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 bool digest_dynamic2(Obj_Entry *, const Elf_Dyn *, const Elf_Dyn *, 92 const Elf_Dyn *); 93 static bool 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(char *, bool); 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 const char **binpath_res); 139 static int parse_args(char* argv[], int argc, bool *use_pathp, int *fdp, 140 const char **argv0); 141 static int parse_integer(const char *); 142 static void *path_enumerate(const char *, path_enum_proc, const char *, void *); 143 static void print_usage(const char *argv0); 144 static void release_object(Obj_Entry *); 145 static int relocate_object_dag(Obj_Entry *root, bool bind_now, 146 Obj_Entry *rtldobj, int flags, RtldLockState *lockstate); 147 static int relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, 148 int flags, RtldLockState *lockstate); 149 static int relocate_objects(Obj_Entry *, bool, Obj_Entry *, int, 150 RtldLockState *); 151 static int resolve_object_ifunc(Obj_Entry *, bool, int, RtldLockState *); 152 static int rtld_dirname(const char *, char *); 153 static int rtld_dirname_abs(const char *, char *); 154 static void *rtld_dlopen(const char *name, int fd, int mode); 155 static void rtld_exit(void); 156 static void rtld_nop_exit(void); 157 static char *search_library_path(const char *, const char *, const char *, 158 int *); 159 static char *search_library_pathfds(const char *, const char *, int *); 160 static const void **get_program_var_addr(const char *, RtldLockState *); 161 static void set_program_var(const char *, const void *); 162 static int symlook_default(SymLook *, const Obj_Entry *refobj); 163 static int symlook_global(SymLook *, DoneList *); 164 static void symlook_init_from_req(SymLook *, const SymLook *); 165 static int symlook_list(SymLook *, const Objlist *, DoneList *); 166 static int symlook_needed(SymLook *, const Needed_Entry *, DoneList *); 167 static int symlook_obj1_sysv(SymLook *, const Obj_Entry *); 168 static int symlook_obj1_gnu(SymLook *, const Obj_Entry *); 169 static void trace_loaded_objects(Obj_Entry *); 170 static void unlink_object(Obj_Entry *); 171 static void unload_object(Obj_Entry *, RtldLockState *lockstate); 172 static void unref_dag(Obj_Entry *); 173 static void ref_dag(Obj_Entry *); 174 static char *origin_subst_one(Obj_Entry *, char *, const char *, 175 const char *, bool); 176 static char *origin_subst(Obj_Entry *, const char *); 177 static bool obj_resolve_origin(Obj_Entry *obj); 178 static void preinit_main(void); 179 static int rtld_verify_versions(const Objlist *); 180 static int rtld_verify_object_versions(Obj_Entry *); 181 static void object_add_name(Obj_Entry *, const char *); 182 static int object_match_name(const Obj_Entry *, const char *); 183 static void ld_utrace_log(int, void *, void *, size_t, int, const char *); 184 static void rtld_fill_dl_phdr_info(const Obj_Entry *obj, 185 struct dl_phdr_info *phdr_info); 186 static uint32_t gnu_hash(const char *); 187 static bool matched_symbol(SymLook *, const Obj_Entry *, Sym_Match_Result *, 188 const unsigned long); 189 190 void r_debug_state(struct r_debug *, struct link_map *) __noinline __exported; 191 void _r_debug_postinit(struct link_map *) __noinline __exported; 192 193 int __sys_openat(int, const char *, int, ...); 194 195 /* 196 * Data declarations. 197 */ 198 static char *error_message; /* Message for dlerror(), or NULL */ 199 struct r_debug r_debug __exported; /* for GDB; */ 200 static bool libmap_disable; /* Disable libmap */ 201 static bool ld_loadfltr; /* Immediate filters processing */ 202 static char *libmap_override; /* Maps to use in addition to libmap.conf */ 203 static bool trust; /* False for setuid and setgid programs */ 204 static bool dangerous_ld_env; /* True if environment variables have been 205 used to affect the libraries loaded */ 206 bool ld_bind_not; /* Disable PLT update */ 207 static char *ld_bind_now; /* Environment variable for immediate binding */ 208 static char *ld_debug; /* Environment variable for debugging */ 209 static char *ld_library_path; /* Environment variable for search path */ 210 static char *ld_library_dirs; /* Environment variable for library descriptors */ 211 static char *ld_preload; /* Environment variable for libraries to 212 load first */ 213 static char *ld_preload_fds; /* Environment variable for libraries represented by 214 descriptors */ 215 static const char *ld_elf_hints_path; /* Environment variable for alternative hints path */ 216 static const char *ld_tracing; /* Called from ldd to print libs */ 217 static char *ld_utrace; /* Use utrace() to log events. */ 218 static struct obj_entry_q obj_list; /* Queue of all loaded objects */ 219 static Obj_Entry *obj_main; /* The main program shared object */ 220 static Obj_Entry obj_rtld; /* The dynamic linker shared object */ 221 static unsigned int obj_count; /* Number of objects in obj_list */ 222 static unsigned int obj_loads; /* Number of loads of objects (gen count) */ 223 224 static Objlist list_global = /* Objects dlopened with RTLD_GLOBAL */ 225 STAILQ_HEAD_INITIALIZER(list_global); 226 static Objlist list_main = /* Objects loaded at program startup */ 227 STAILQ_HEAD_INITIALIZER(list_main); 228 static Objlist list_fini = /* Objects needing fini() calls */ 229 STAILQ_HEAD_INITIALIZER(list_fini); 230 231 Elf_Sym sym_zero; /* For resolving undefined weak refs. */ 232 233 #define GDB_STATE(s,m) r_debug.r_state = s; r_debug_state(&r_debug,m); 234 235 extern Elf_Dyn _DYNAMIC; 236 #pragma weak _DYNAMIC 237 238 int dlclose(void *) __exported; 239 char *dlerror(void) __exported; 240 void *dlopen(const char *, int) __exported; 241 void *fdlopen(int, int) __exported; 242 void *dlsym(void *, const char *) __exported; 243 dlfunc_t dlfunc(void *, const char *) __exported; 244 void *dlvsym(void *, const char *, const char *) __exported; 245 int dladdr(const void *, Dl_info *) __exported; 246 void dllockinit(void *, void *(*)(void *), void (*)(void *), void (*)(void *), 247 void (*)(void *), void (*)(void *), void (*)(void *)) __exported; 248 int dlinfo(void *, int , void *) __exported; 249 int dl_iterate_phdr(__dl_iterate_hdr_callback, void *) __exported; 250 int _rtld_addr_phdr(const void *, struct dl_phdr_info *) __exported; 251 int _rtld_get_stack_prot(void) __exported; 252 int _rtld_is_dlopened(void *) __exported; 253 void _rtld_error(const char *, ...) __exported; 254 255 /* Only here to fix -Wmissing-prototypes warnings */ 256 int __getosreldate(void); 257 func_ptr_type _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp); 258 Elf_Addr _rtld_bind(Obj_Entry *obj, Elf_Size reloff); 259 260 261 int npagesizes; 262 static int osreldate; 263 size_t *pagesizes; 264 265 static int stack_prot = PROT_READ | PROT_WRITE | RTLD_DEFAULT_STACK_EXEC; 266 static int max_stack_flags; 267 268 /* 269 * Global declarations normally provided by crt1. The dynamic linker is 270 * not built with crt1, so we have to provide them ourselves. 271 */ 272 char *__progname; 273 char **environ; 274 275 /* 276 * Used to pass argc, argv to init functions. 277 */ 278 int main_argc; 279 char **main_argv; 280 281 /* 282 * Globals to control TLS allocation. 283 */ 284 size_t tls_last_offset; /* Static TLS offset of last module */ 285 size_t tls_last_size; /* Static TLS size of last module */ 286 size_t tls_static_space; /* Static TLS space allocated */ 287 static size_t tls_static_max_align; 288 Elf_Addr tls_dtv_generation = 1; /* Used to detect when dtv size changes */ 289 int tls_max_index = 1; /* Largest module index allocated */ 290 291 static bool ld_library_path_rpath = false; 292 bool ld_fast_sigblock = false; 293 294 /* 295 * Globals for path names, and such 296 */ 297 const char *ld_elf_hints_default = _PATH_ELF_HINTS; 298 const char *ld_path_libmap_conf = _PATH_LIBMAP_CONF; 299 const char *ld_path_rtld = _PATH_RTLD; 300 const char *ld_standard_library_path = STANDARD_LIBRARY_PATH; 301 const char *ld_env_prefix = LD_; 302 303 static void (*rtld_exit_ptr)(void); 304 305 /* 306 * Fill in a DoneList with an allocation large enough to hold all of 307 * the currently-loaded objects. Keep this as a macro since it calls 308 * alloca and we want that to occur within the scope of the caller. 309 */ 310 #define donelist_init(dlp) \ 311 ((dlp)->objs = alloca(obj_count * sizeof (dlp)->objs[0]), \ 312 assert((dlp)->objs != NULL), \ 313 (dlp)->num_alloc = obj_count, \ 314 (dlp)->num_used = 0) 315 316 #define LD_UTRACE(e, h, mb, ms, r, n) do { \ 317 if (ld_utrace != NULL) \ 318 ld_utrace_log(e, h, mb, ms, r, n); \ 319 } while (0) 320 321 static void 322 ld_utrace_log(int event, void *handle, void *mapbase, size_t mapsize, 323 int refcnt, const char *name) 324 { 325 struct utrace_rtld ut; 326 static const char rtld_utrace_sig[RTLD_UTRACE_SIG_SZ] = RTLD_UTRACE_SIG; 327 328 memcpy(ut.sig, rtld_utrace_sig, sizeof(ut.sig)); 329 ut.event = event; 330 ut.handle = handle; 331 ut.mapbase = mapbase; 332 ut.mapsize = mapsize; 333 ut.refcnt = refcnt; 334 bzero(ut.name, sizeof(ut.name)); 335 if (name) 336 strlcpy(ut.name, name, sizeof(ut.name)); 337 utrace(&ut, sizeof(ut)); 338 } 339 340 #ifdef RTLD_VARIANT_ENV_NAMES 341 /* 342 * construct the env variable based on the type of binary that's 343 * running. 344 */ 345 static inline const char * 346 _LD(const char *var) 347 { 348 static char buffer[128]; 349 350 strlcpy(buffer, ld_env_prefix, sizeof(buffer)); 351 strlcat(buffer, var, sizeof(buffer)); 352 return (buffer); 353 } 354 #else 355 #define _LD(x) LD_ x 356 #endif 357 358 /* 359 * Main entry point for dynamic linking. The first argument is the 360 * stack pointer. The stack is expected to be laid out as described 361 * in the SVR4 ABI specification, Intel 386 Processor Supplement. 362 * Specifically, the stack pointer points to a word containing 363 * ARGC. Following that in the stack is a null-terminated sequence 364 * of pointers to argument strings. Then comes a null-terminated 365 * sequence of pointers to environment strings. Finally, there is a 366 * sequence of "auxiliary vector" entries. 367 * 368 * The second argument points to a place to store the dynamic linker's 369 * exit procedure pointer and the third to a place to store the main 370 * program's object. 371 * 372 * The return value is the main program's entry point. 373 */ 374 func_ptr_type 375 _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp) 376 { 377 Elf_Auxinfo *aux, *auxp, *auxpf, *aux_info[AT_COUNT]; 378 Objlist_Entry *entry; 379 Obj_Entry *last_interposer, *obj, *preload_tail; 380 const Elf_Phdr *phdr; 381 Objlist initlist; 382 RtldLockState lockstate; 383 struct stat st; 384 Elf_Addr *argcp; 385 char **argv, **env, **envp, *kexecpath, *library_path_rpath; 386 const char *argv0, *binpath; 387 caddr_t imgentry; 388 char buf[MAXPATHLEN]; 389 int argc, fd, i, mib[4], old_osrel, osrel, phnum, rtld_argc; 390 size_t sz; 391 #ifdef __powerpc__ 392 int old_auxv_format = 1; 393 #endif 394 bool dir_enable, direct_exec, explicit_fd, search_in_path; 395 396 /* 397 * On entry, the dynamic linker itself has not been relocated yet. 398 * Be very careful not to reference any global data until after 399 * init_rtld has returned. It is OK to reference file-scope statics 400 * and string constants, and to call static and global functions. 401 */ 402 403 /* Find the auxiliary vector on the stack. */ 404 argcp = sp; 405 argc = *sp++; 406 argv = (char **) sp; 407 sp += argc + 1; /* Skip over arguments and NULL terminator */ 408 env = (char **) sp; 409 while (*sp++ != 0) /* Skip over environment, and NULL terminator */ 410 ; 411 aux = (Elf_Auxinfo *) sp; 412 413 /* Digest the auxiliary vector. */ 414 for (i = 0; i < AT_COUNT; i++) 415 aux_info[i] = NULL; 416 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) { 417 if (auxp->a_type < AT_COUNT) 418 aux_info[auxp->a_type] = auxp; 419 #ifdef __powerpc__ 420 if (auxp->a_type == 23) /* AT_STACKPROT */ 421 old_auxv_format = 0; 422 #endif 423 } 424 425 #ifdef __powerpc__ 426 if (old_auxv_format) { 427 /* Remap from old-style auxv numbers. */ 428 aux_info[23] = aux_info[21]; /* AT_STACKPROT */ 429 aux_info[21] = aux_info[19]; /* AT_PAGESIZESLEN */ 430 aux_info[19] = aux_info[17]; /* AT_NCPUS */ 431 aux_info[17] = aux_info[15]; /* AT_CANARYLEN */ 432 aux_info[15] = aux_info[13]; /* AT_EXECPATH */ 433 aux_info[13] = NULL; /* AT_GID */ 434 435 aux_info[20] = aux_info[18]; /* AT_PAGESIZES */ 436 aux_info[18] = aux_info[16]; /* AT_OSRELDATE */ 437 aux_info[16] = aux_info[14]; /* AT_CANARY */ 438 aux_info[14] = NULL; /* AT_EGID */ 439 } 440 #endif 441 442 /* Initialize and relocate ourselves. */ 443 assert(aux_info[AT_BASE] != NULL); 444 init_rtld((caddr_t) aux_info[AT_BASE]->a_un.a_ptr, aux_info); 445 446 __progname = obj_rtld.path; 447 argv0 = argv[0] != NULL ? argv[0] : "(null)"; 448 environ = env; 449 main_argc = argc; 450 main_argv = argv; 451 452 if (aux_info[AT_BSDFLAGS] != NULL && 453 (aux_info[AT_BSDFLAGS]->a_un.a_val & ELF_BSDF_SIGFASTBLK) != 0) 454 ld_fast_sigblock = true; 455 456 trust = !issetugid(); 457 direct_exec = false; 458 459 md_abi_variant_hook(aux_info); 460 461 fd = -1; 462 if (aux_info[AT_EXECFD] != NULL) { 463 fd = aux_info[AT_EXECFD]->a_un.a_val; 464 } else { 465 assert(aux_info[AT_PHDR] != NULL); 466 phdr = (const Elf_Phdr *)aux_info[AT_PHDR]->a_un.a_ptr; 467 if (phdr == obj_rtld.phdr) { 468 if (!trust) { 469 _rtld_error("Tainted process refusing to run binary %s", 470 argv0); 471 rtld_die(); 472 } 473 direct_exec = true; 474 475 dbg("opening main program in direct exec mode"); 476 if (argc >= 2) { 477 rtld_argc = parse_args(argv, argc, &search_in_path, &fd, &argv0); 478 explicit_fd = (fd != -1); 479 binpath = NULL; 480 if (!explicit_fd) 481 fd = open_binary_fd(argv0, search_in_path, &binpath); 482 if (fstat(fd, &st) == -1) { 483 _rtld_error("Failed to fstat FD %d (%s): %s", fd, 484 explicit_fd ? "user-provided descriptor" : argv0, 485 rtld_strerror(errno)); 486 rtld_die(); 487 } 488 489 /* 490 * Rough emulation of the permission checks done by 491 * execve(2), only Unix DACs are checked, ACLs are 492 * ignored. Preserve the semantic of disabling owner 493 * to execute if owner x bit is cleared, even if 494 * others x bit is enabled. 495 * mmap(2) does not allow to mmap with PROT_EXEC if 496 * binary' file comes from noexec mount. We cannot 497 * set a text reference on the binary. 498 */ 499 dir_enable = false; 500 if (st.st_uid == geteuid()) { 501 if ((st.st_mode & S_IXUSR) != 0) 502 dir_enable = true; 503 } else if (st.st_gid == getegid()) { 504 if ((st.st_mode & S_IXGRP) != 0) 505 dir_enable = true; 506 } else if ((st.st_mode & S_IXOTH) != 0) { 507 dir_enable = true; 508 } 509 if (!dir_enable) { 510 _rtld_error("No execute permission for binary %s", 511 argv0); 512 rtld_die(); 513 } 514 515 /* 516 * For direct exec mode, argv[0] is the interpreter 517 * name, we must remove it and shift arguments left 518 * before invoking binary main. Since stack layout 519 * places environment pointers and aux vectors right 520 * after the terminating NULL, we must shift 521 * environment and aux as well. 522 */ 523 main_argc = argc - rtld_argc; 524 for (i = 0; i <= main_argc; i++) 525 argv[i] = argv[i + rtld_argc]; 526 *argcp -= rtld_argc; 527 environ = env = envp = argv + main_argc + 1; 528 dbg("move env from %p to %p", envp + rtld_argc, envp); 529 do { 530 *envp = *(envp + rtld_argc); 531 } while (*envp++ != NULL); 532 aux = auxp = (Elf_Auxinfo *)envp; 533 auxpf = (Elf_Auxinfo *)(envp + rtld_argc); 534 dbg("move aux from %p to %p", auxpf, aux); 535 /* XXXKIB insert place for AT_EXECPATH if not present */ 536 for (;; auxp++, auxpf++) { 537 *auxp = *auxpf; 538 if (auxp->a_type == AT_NULL) 539 break; 540 } 541 /* Since the auxiliary vector has moved, redigest it. */ 542 for (i = 0; i < AT_COUNT; i++) 543 aux_info[i] = NULL; 544 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) { 545 if (auxp->a_type < AT_COUNT) 546 aux_info[auxp->a_type] = auxp; 547 } 548 549 /* Point AT_EXECPATH auxv and aux_info to the binary path. */ 550 if (binpath == NULL) { 551 aux_info[AT_EXECPATH] = NULL; 552 } else { 553 if (aux_info[AT_EXECPATH] == NULL) { 554 aux_info[AT_EXECPATH] = xmalloc(sizeof(Elf_Auxinfo)); 555 aux_info[AT_EXECPATH]->a_type = AT_EXECPATH; 556 } 557 aux_info[AT_EXECPATH]->a_un.a_ptr = __DECONST(void *, 558 binpath); 559 } 560 } else { 561 _rtld_error("No binary"); 562 rtld_die(); 563 } 564 } 565 } 566 567 ld_bind_now = getenv(_LD("BIND_NOW")); 568 569 /* 570 * If the process is tainted, then we un-set the dangerous environment 571 * variables. The process will be marked as tainted until setuid(2) 572 * is called. If any child process calls setuid(2) we do not want any 573 * future processes to honor the potentially un-safe variables. 574 */ 575 if (!trust) { 576 if (unsetenv(_LD("PRELOAD")) || unsetenv(_LD("LIBMAP")) || 577 unsetenv(_LD("LIBRARY_PATH")) || unsetenv(_LD("LIBRARY_PATH_FDS")) || 578 unsetenv(_LD("LIBMAP_DISABLE")) || unsetenv(_LD("BIND_NOT")) || 579 unsetenv(_LD("DEBUG")) || unsetenv(_LD("ELF_HINTS_PATH")) || 580 unsetenv(_LD("LOADFLTR")) || unsetenv(_LD("LIBRARY_PATH_RPATH")) || 581 unsetenv(_LD("PRELOAD_FDS"))) { 582 _rtld_error("environment corrupt; aborting"); 583 rtld_die(); 584 } 585 } 586 ld_debug = getenv(_LD("DEBUG")); 587 if (ld_bind_now == NULL) 588 ld_bind_not = getenv(_LD("BIND_NOT")) != NULL; 589 libmap_disable = getenv(_LD("LIBMAP_DISABLE")) != NULL; 590 libmap_override = getenv(_LD("LIBMAP")); 591 ld_library_path = getenv(_LD("LIBRARY_PATH")); 592 ld_library_dirs = getenv(_LD("LIBRARY_PATH_FDS")); 593 ld_preload = getenv(_LD("PRELOAD")); 594 ld_preload_fds = getenv(_LD("PRELOAD_FDS")); 595 ld_elf_hints_path = getenv(_LD("ELF_HINTS_PATH")); 596 ld_loadfltr = getenv(_LD("LOADFLTR")) != NULL; 597 library_path_rpath = getenv(_LD("LIBRARY_PATH_RPATH")); 598 if (library_path_rpath != NULL) { 599 if (library_path_rpath[0] == 'y' || 600 library_path_rpath[0] == 'Y' || 601 library_path_rpath[0] == '1') 602 ld_library_path_rpath = true; 603 else 604 ld_library_path_rpath = false; 605 } 606 dangerous_ld_env = libmap_disable || (libmap_override != NULL) || 607 (ld_library_path != NULL) || (ld_preload != NULL) || 608 (ld_elf_hints_path != NULL) || ld_loadfltr; 609 ld_tracing = getenv(_LD("TRACE_LOADED_OBJECTS")); 610 ld_utrace = getenv(_LD("UTRACE")); 611 612 if ((ld_elf_hints_path == NULL) || strlen(ld_elf_hints_path) == 0) 613 ld_elf_hints_path = ld_elf_hints_default; 614 615 if (ld_debug != NULL && *ld_debug != '\0') 616 debug = 1; 617 dbg("%s is initialized, base address = %p", __progname, 618 (caddr_t) aux_info[AT_BASE]->a_un.a_ptr); 619 dbg("RTLD dynamic = %p", obj_rtld.dynamic); 620 dbg("RTLD pltgot = %p", obj_rtld.pltgot); 621 622 dbg("initializing thread locks"); 623 lockdflt_init(); 624 625 /* 626 * Load the main program, or process its program header if it is 627 * already loaded. 628 */ 629 if (fd != -1) { /* Load the main program. */ 630 dbg("loading main program"); 631 obj_main = map_object(fd, argv0, NULL); 632 close(fd); 633 if (obj_main == NULL) 634 rtld_die(); 635 max_stack_flags = obj_main->stack_flags; 636 } else { /* Main program already loaded. */ 637 dbg("processing main program's program header"); 638 assert(aux_info[AT_PHDR] != NULL); 639 phdr = (const Elf_Phdr *) aux_info[AT_PHDR]->a_un.a_ptr; 640 assert(aux_info[AT_PHNUM] != NULL); 641 phnum = aux_info[AT_PHNUM]->a_un.a_val; 642 assert(aux_info[AT_PHENT] != NULL); 643 assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr)); 644 assert(aux_info[AT_ENTRY] != NULL); 645 imgentry = (caddr_t) aux_info[AT_ENTRY]->a_un.a_ptr; 646 if ((obj_main = digest_phdr(phdr, phnum, imgentry, argv0)) == NULL) 647 rtld_die(); 648 } 649 650 if (aux_info[AT_EXECPATH] != NULL && fd == -1) { 651 kexecpath = aux_info[AT_EXECPATH]->a_un.a_ptr; 652 dbg("AT_EXECPATH %p %s", kexecpath, kexecpath); 653 if (kexecpath[0] == '/') 654 obj_main->path = kexecpath; 655 else if (getcwd(buf, sizeof(buf)) == NULL || 656 strlcat(buf, "/", sizeof(buf)) >= sizeof(buf) || 657 strlcat(buf, kexecpath, sizeof(buf)) >= sizeof(buf)) 658 obj_main->path = xstrdup(argv0); 659 else 660 obj_main->path = xstrdup(buf); 661 } else { 662 dbg("No AT_EXECPATH or direct exec"); 663 obj_main->path = xstrdup(argv0); 664 } 665 dbg("obj_main path %s", obj_main->path); 666 obj_main->mainprog = true; 667 668 if (aux_info[AT_STACKPROT] != NULL && 669 aux_info[AT_STACKPROT]->a_un.a_val != 0) 670 stack_prot = aux_info[AT_STACKPROT]->a_un.a_val; 671 672 #ifndef COMPAT_32BIT 673 /* 674 * Get the actual dynamic linker pathname from the executable if 675 * possible. (It should always be possible.) That ensures that 676 * gdb will find the right dynamic linker even if a non-standard 677 * one is being used. 678 */ 679 if (obj_main->interp != NULL && 680 strcmp(obj_main->interp, obj_rtld.path) != 0) { 681 free(obj_rtld.path); 682 obj_rtld.path = xstrdup(obj_main->interp); 683 __progname = obj_rtld.path; 684 } 685 #endif 686 687 if (!digest_dynamic(obj_main, 0)) 688 rtld_die(); 689 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", 690 obj_main->path, obj_main->valid_hash_sysv, obj_main->valid_hash_gnu, 691 obj_main->dynsymcount); 692 693 linkmap_add(obj_main); 694 linkmap_add(&obj_rtld); 695 696 /* Link the main program into the list of objects. */ 697 TAILQ_INSERT_HEAD(&obj_list, obj_main, next); 698 obj_count++; 699 obj_loads++; 700 701 /* Initialize a fake symbol for resolving undefined weak references. */ 702 sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE); 703 sym_zero.st_shndx = SHN_UNDEF; 704 sym_zero.st_value = -(uintptr_t)obj_main->relocbase; 705 706 if (!libmap_disable) 707 libmap_disable = (bool)lm_init(libmap_override); 708 709 dbg("loading LD_PRELOAD_FDS libraries"); 710 if (load_preload_objects(ld_preload_fds, true) == -1) 711 rtld_die(); 712 713 dbg("loading LD_PRELOAD libraries"); 714 if (load_preload_objects(ld_preload, false) == -1) 715 rtld_die(); 716 preload_tail = globallist_curr(TAILQ_LAST(&obj_list, obj_entry_q)); 717 718 dbg("loading needed objects"); 719 if (load_needed_objects(obj_main, ld_tracing != NULL ? RTLD_LO_TRACE : 720 0) == -1) 721 rtld_die(); 722 723 /* Make a list of all objects loaded at startup. */ 724 last_interposer = obj_main; 725 TAILQ_FOREACH(obj, &obj_list, next) { 726 if (obj->marker) 727 continue; 728 if (obj->z_interpose && obj != obj_main) { 729 objlist_put_after(&list_main, last_interposer, obj); 730 last_interposer = obj; 731 } else { 732 objlist_push_tail(&list_main, obj); 733 } 734 obj->refcount++; 735 } 736 737 dbg("checking for required versions"); 738 if (rtld_verify_versions(&list_main) == -1 && !ld_tracing) 739 rtld_die(); 740 741 if (ld_tracing) { /* We're done */ 742 trace_loaded_objects(obj_main); 743 exit(0); 744 } 745 746 if (getenv(_LD("DUMP_REL_PRE")) != NULL) { 747 dump_relocations(obj_main); 748 exit (0); 749 } 750 751 /* 752 * Processing tls relocations requires having the tls offsets 753 * initialized. Prepare offsets before starting initial 754 * relocation processing. 755 */ 756 dbg("initializing initial thread local storage offsets"); 757 STAILQ_FOREACH(entry, &list_main, link) { 758 /* 759 * Allocate all the initial objects out of the static TLS 760 * block even if they didn't ask for it. 761 */ 762 allocate_tls_offset(entry->obj); 763 } 764 765 if (relocate_objects(obj_main, 766 ld_bind_now != NULL && *ld_bind_now != '\0', 767 &obj_rtld, SYMLOOK_EARLY, NULL) == -1) 768 rtld_die(); 769 770 dbg("doing copy relocations"); 771 if (do_copy_relocations(obj_main) == -1) 772 rtld_die(); 773 774 if (getenv(_LD("DUMP_REL_POST")) != NULL) { 775 dump_relocations(obj_main); 776 exit (0); 777 } 778 779 ifunc_init(aux); 780 781 /* 782 * Setup TLS for main thread. This must be done after the 783 * relocations are processed, since tls initialization section 784 * might be the subject for relocations. 785 */ 786 dbg("initializing initial thread local storage"); 787 allocate_initial_tls(globallist_curr(TAILQ_FIRST(&obj_list))); 788 789 dbg("initializing key program variables"); 790 set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : ""); 791 set_program_var("environ", env); 792 set_program_var("__elf_aux_vector", aux); 793 794 /* Make a list of init functions to call. */ 795 objlist_init(&initlist); 796 initlist_add_objects(globallist_curr(TAILQ_FIRST(&obj_list)), 797 preload_tail, &initlist); 798 799 r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */ 800 801 map_stacks_exec(NULL); 802 803 if (!obj_main->crt_no_init) { 804 /* 805 * Make sure we don't call the main program's init and fini 806 * functions for binaries linked with old crt1 which calls 807 * _init itself. 808 */ 809 obj_main->init = obj_main->fini = (Elf_Addr)NULL; 810 obj_main->preinit_array = obj_main->init_array = 811 obj_main->fini_array = (Elf_Addr)NULL; 812 } 813 814 if (direct_exec) { 815 /* Set osrel for direct-execed binary */ 816 mib[0] = CTL_KERN; 817 mib[1] = KERN_PROC; 818 mib[2] = KERN_PROC_OSREL; 819 mib[3] = getpid(); 820 osrel = obj_main->osrel; 821 sz = sizeof(old_osrel); 822 dbg("setting osrel to %d", osrel); 823 (void)sysctl(mib, 4, &old_osrel, &sz, &osrel, sizeof(osrel)); 824 } 825 826 wlock_acquire(rtld_bind_lock, &lockstate); 827 828 dbg("resolving ifuncs"); 829 if (initlist_objects_ifunc(&initlist, ld_bind_now != NULL && 830 *ld_bind_now != '\0', SYMLOOK_EARLY, &lockstate) == -1) 831 rtld_die(); 832 833 rtld_exit_ptr = rtld_exit; 834 if (obj_main->crt_no_init) 835 preinit_main(); 836 objlist_call_init(&initlist, &lockstate); 837 _r_debug_postinit(&obj_main->linkmap); 838 objlist_clear(&initlist); 839 dbg("loading filtees"); 840 TAILQ_FOREACH(obj, &obj_list, next) { 841 if (obj->marker) 842 continue; 843 if (ld_loadfltr || obj->z_loadfltr) 844 load_filtees(obj, 0, &lockstate); 845 } 846 847 dbg("enforcing main obj relro"); 848 if (obj_enforce_relro(obj_main) == -1) 849 rtld_die(); 850 851 lock_release(rtld_bind_lock, &lockstate); 852 853 dbg("transferring control to program entry point = %p", obj_main->entry); 854 855 /* Return the exit procedure and the program entry point. */ 856 *exit_proc = rtld_exit_ptr; 857 *objp = obj_main; 858 return (func_ptr_type) obj_main->entry; 859 } 860 861 void * 862 rtld_resolve_ifunc(const Obj_Entry *obj, const Elf_Sym *def) 863 { 864 void *ptr; 865 Elf_Addr target; 866 867 ptr = (void *)make_function_pointer(def, obj); 868 target = call_ifunc_resolver(ptr); 869 return ((void *)target); 870 } 871 872 /* 873 * NB: MIPS uses a private version of this function (_mips_rtld_bind). 874 * Changes to this function should be applied there as well. 875 */ 876 Elf_Addr 877 _rtld_bind(Obj_Entry *obj, Elf_Size reloff) 878 { 879 const Elf_Rel *rel; 880 const Elf_Sym *def; 881 const Obj_Entry *defobj; 882 Elf_Addr *where; 883 Elf_Addr target; 884 RtldLockState lockstate; 885 886 rlock_acquire(rtld_bind_lock, &lockstate); 887 if (sigsetjmp(lockstate.env, 0) != 0) 888 lock_upgrade(rtld_bind_lock, &lockstate); 889 if (obj->pltrel) 890 rel = (const Elf_Rel *)((const char *)obj->pltrel + reloff); 891 else 892 rel = (const Elf_Rel *)((const char *)obj->pltrela + reloff); 893 894 where = (Elf_Addr *)(obj->relocbase + rel->r_offset); 895 def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, SYMLOOK_IN_PLT, 896 NULL, &lockstate); 897 if (def == NULL) 898 rtld_die(); 899 if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 900 target = (Elf_Addr)rtld_resolve_ifunc(defobj, def); 901 else 902 target = (Elf_Addr)(defobj->relocbase + def->st_value); 903 904 dbg("\"%s\" in \"%s\" ==> %p in \"%s\"", 905 defobj->strtab + def->st_name, 906 obj->path == NULL ? NULL : basename(obj->path), 907 (void *)target, 908 defobj->path == NULL ? NULL : basename(defobj->path)); 909 910 /* 911 * Write the new contents for the jmpslot. Note that depending on 912 * architecture, the value which we need to return back to the 913 * lazy binding trampoline may or may not be the target 914 * address. The value returned from reloc_jmpslot() is the value 915 * that the trampoline needs. 916 */ 917 target = reloc_jmpslot(where, target, defobj, obj, rel); 918 lock_release(rtld_bind_lock, &lockstate); 919 return target; 920 } 921 922 /* 923 * Error reporting function. Use it like printf. If formats the message 924 * into a buffer, and sets things up so that the next call to dlerror() 925 * will return the message. 926 */ 927 void 928 _rtld_error(const char *fmt, ...) 929 { 930 static char buf[512]; 931 va_list ap; 932 933 va_start(ap, fmt); 934 rtld_vsnprintf(buf, sizeof buf, fmt, ap); 935 error_message = buf; 936 va_end(ap); 937 LD_UTRACE(UTRACE_RTLD_ERROR, NULL, NULL, 0, 0, error_message); 938 } 939 940 /* 941 * Return a dynamically-allocated copy of the current error message, if any. 942 */ 943 static char * 944 errmsg_save(void) 945 { 946 return error_message == NULL ? NULL : xstrdup(error_message); 947 } 948 949 /* 950 * Restore the current error message from a copy which was previously saved 951 * by errmsg_save(). The copy is freed. 952 */ 953 static void 954 errmsg_restore(char *saved_msg) 955 { 956 if (saved_msg == NULL) 957 error_message = NULL; 958 else { 959 _rtld_error("%s", saved_msg); 960 free(saved_msg); 961 } 962 } 963 964 static const char * 965 basename(const char *name) 966 { 967 const char *p = strrchr(name, '/'); 968 return p != NULL ? p + 1 : name; 969 } 970 971 static struct utsname uts; 972 973 static char * 974 origin_subst_one(Obj_Entry *obj, char *real, const char *kw, 975 const char *subst, bool may_free) 976 { 977 char *p, *p1, *res, *resp; 978 int subst_len, kw_len, subst_count, old_len, new_len; 979 980 kw_len = strlen(kw); 981 982 /* 983 * First, count the number of the keyword occurrences, to 984 * preallocate the final string. 985 */ 986 for (p = real, subst_count = 0;; p = p1 + kw_len, subst_count++) { 987 p1 = strstr(p, kw); 988 if (p1 == NULL) 989 break; 990 } 991 992 /* 993 * If the keyword is not found, just return. 994 * 995 * Return non-substituted string if resolution failed. We 996 * cannot do anything more reasonable, the failure mode of the 997 * caller is unresolved library anyway. 998 */ 999 if (subst_count == 0 || (obj != NULL && !obj_resolve_origin(obj))) 1000 return (may_free ? real : xstrdup(real)); 1001 if (obj != NULL) 1002 subst = obj->origin_path; 1003 1004 /* 1005 * There is indeed something to substitute. Calculate the 1006 * length of the resulting string, and allocate it. 1007 */ 1008 subst_len = strlen(subst); 1009 old_len = strlen(real); 1010 new_len = old_len + (subst_len - kw_len) * subst_count; 1011 res = xmalloc(new_len + 1); 1012 1013 /* 1014 * Now, execute the substitution loop. 1015 */ 1016 for (p = real, resp = res, *resp = '\0';;) { 1017 p1 = strstr(p, kw); 1018 if (p1 != NULL) { 1019 /* Copy the prefix before keyword. */ 1020 memcpy(resp, p, p1 - p); 1021 resp += p1 - p; 1022 /* Keyword replacement. */ 1023 memcpy(resp, subst, subst_len); 1024 resp += subst_len; 1025 *resp = '\0'; 1026 p = p1 + kw_len; 1027 } else 1028 break; 1029 } 1030 1031 /* Copy to the end of string and finish. */ 1032 strcat(resp, p); 1033 if (may_free) 1034 free(real); 1035 return (res); 1036 } 1037 1038 static char * 1039 origin_subst(Obj_Entry *obj, const char *real) 1040 { 1041 char *res1, *res2, *res3, *res4; 1042 1043 if (obj == NULL || !trust) 1044 return (xstrdup(real)); 1045 if (uts.sysname[0] == '\0') { 1046 if (uname(&uts) != 0) { 1047 _rtld_error("utsname failed: %d", errno); 1048 return (NULL); 1049 } 1050 } 1051 /* __DECONST is safe here since without may_free real is unchanged */ 1052 res1 = origin_subst_one(obj, __DECONST(char *, real), "$ORIGIN", NULL, 1053 false); 1054 res2 = origin_subst_one(NULL, res1, "$OSNAME", uts.sysname, true); 1055 res3 = origin_subst_one(NULL, res2, "$OSREL", uts.release, true); 1056 res4 = origin_subst_one(NULL, res3, "$PLATFORM", uts.machine, true); 1057 return (res4); 1058 } 1059 1060 void 1061 rtld_die(void) 1062 { 1063 const char *msg = dlerror(); 1064 1065 if (msg == NULL) 1066 msg = "Fatal error"; 1067 rtld_fdputstr(STDERR_FILENO, _BASENAME_RTLD ": "); 1068 rtld_fdputstr(STDERR_FILENO, msg); 1069 rtld_fdputchar(STDERR_FILENO, '\n'); 1070 _exit(1); 1071 } 1072 1073 /* 1074 * Process a shared object's DYNAMIC section, and save the important 1075 * information in its Obj_Entry structure. 1076 */ 1077 static void 1078 digest_dynamic1(Obj_Entry *obj, int early, const Elf_Dyn **dyn_rpath, 1079 const Elf_Dyn **dyn_soname, const Elf_Dyn **dyn_runpath) 1080 { 1081 const Elf_Dyn *dynp; 1082 Needed_Entry **needed_tail = &obj->needed; 1083 Needed_Entry **needed_filtees_tail = &obj->needed_filtees; 1084 Needed_Entry **needed_aux_filtees_tail = &obj->needed_aux_filtees; 1085 const Elf_Hashelt *hashtab; 1086 const Elf32_Word *hashval; 1087 Elf32_Word bkt, nmaskwords; 1088 int bloom_size32; 1089 int plttype = DT_REL; 1090 1091 *dyn_rpath = NULL; 1092 *dyn_soname = NULL; 1093 *dyn_runpath = NULL; 1094 1095 obj->bind_now = false; 1096 dynp = obj->dynamic; 1097 if (dynp == NULL) 1098 return; 1099 for (; dynp->d_tag != DT_NULL; dynp++) { 1100 switch (dynp->d_tag) { 1101 1102 case DT_REL: 1103 obj->rel = (const Elf_Rel *)(obj->relocbase + dynp->d_un.d_ptr); 1104 break; 1105 1106 case DT_RELSZ: 1107 obj->relsize = dynp->d_un.d_val; 1108 break; 1109 1110 case DT_RELENT: 1111 assert(dynp->d_un.d_val == sizeof(Elf_Rel)); 1112 break; 1113 1114 case DT_JMPREL: 1115 obj->pltrel = (const Elf_Rel *) 1116 (obj->relocbase + dynp->d_un.d_ptr); 1117 break; 1118 1119 case DT_PLTRELSZ: 1120 obj->pltrelsize = dynp->d_un.d_val; 1121 break; 1122 1123 case DT_RELA: 1124 obj->rela = (const Elf_Rela *)(obj->relocbase + dynp->d_un.d_ptr); 1125 break; 1126 1127 case DT_RELASZ: 1128 obj->relasize = dynp->d_un.d_val; 1129 break; 1130 1131 case DT_RELAENT: 1132 assert(dynp->d_un.d_val == sizeof(Elf_Rela)); 1133 break; 1134 1135 case DT_PLTREL: 1136 plttype = dynp->d_un.d_val; 1137 assert(dynp->d_un.d_val == DT_REL || plttype == DT_RELA); 1138 break; 1139 1140 case DT_SYMTAB: 1141 obj->symtab = (const Elf_Sym *) 1142 (obj->relocbase + dynp->d_un.d_ptr); 1143 break; 1144 1145 case DT_SYMENT: 1146 assert(dynp->d_un.d_val == sizeof(Elf_Sym)); 1147 break; 1148 1149 case DT_STRTAB: 1150 obj->strtab = (const char *)(obj->relocbase + dynp->d_un.d_ptr); 1151 break; 1152 1153 case DT_STRSZ: 1154 obj->strsize = dynp->d_un.d_val; 1155 break; 1156 1157 case DT_VERNEED: 1158 obj->verneed = (const Elf_Verneed *)(obj->relocbase + 1159 dynp->d_un.d_val); 1160 break; 1161 1162 case DT_VERNEEDNUM: 1163 obj->verneednum = dynp->d_un.d_val; 1164 break; 1165 1166 case DT_VERDEF: 1167 obj->verdef = (const Elf_Verdef *)(obj->relocbase + 1168 dynp->d_un.d_val); 1169 break; 1170 1171 case DT_VERDEFNUM: 1172 obj->verdefnum = dynp->d_un.d_val; 1173 break; 1174 1175 case DT_VERSYM: 1176 obj->versyms = (const Elf_Versym *)(obj->relocbase + 1177 dynp->d_un.d_val); 1178 break; 1179 1180 case DT_HASH: 1181 { 1182 hashtab = (const Elf_Hashelt *)(obj->relocbase + 1183 dynp->d_un.d_ptr); 1184 obj->nbuckets = hashtab[0]; 1185 obj->nchains = hashtab[1]; 1186 obj->buckets = hashtab + 2; 1187 obj->chains = obj->buckets + obj->nbuckets; 1188 obj->valid_hash_sysv = obj->nbuckets > 0 && obj->nchains > 0 && 1189 obj->buckets != NULL; 1190 } 1191 break; 1192 1193 case DT_GNU_HASH: 1194 { 1195 hashtab = (const Elf_Hashelt *)(obj->relocbase + 1196 dynp->d_un.d_ptr); 1197 obj->nbuckets_gnu = hashtab[0]; 1198 obj->symndx_gnu = hashtab[1]; 1199 nmaskwords = hashtab[2]; 1200 bloom_size32 = (__ELF_WORD_SIZE / 32) * nmaskwords; 1201 obj->maskwords_bm_gnu = nmaskwords - 1; 1202 obj->shift2_gnu = hashtab[3]; 1203 obj->bloom_gnu = (const Elf_Addr *)(hashtab + 4); 1204 obj->buckets_gnu = hashtab + 4 + bloom_size32; 1205 obj->chain_zero_gnu = obj->buckets_gnu + obj->nbuckets_gnu - 1206 obj->symndx_gnu; 1207 /* Number of bitmask words is required to be power of 2 */ 1208 obj->valid_hash_gnu = powerof2(nmaskwords) && 1209 obj->nbuckets_gnu > 0 && obj->buckets_gnu != NULL; 1210 } 1211 break; 1212 1213 case DT_NEEDED: 1214 if (!obj->rtld) { 1215 Needed_Entry *nep = NEW(Needed_Entry); 1216 nep->name = dynp->d_un.d_val; 1217 nep->obj = NULL; 1218 nep->next = NULL; 1219 1220 *needed_tail = nep; 1221 needed_tail = &nep->next; 1222 } 1223 break; 1224 1225 case DT_FILTER: 1226 if (!obj->rtld) { 1227 Needed_Entry *nep = NEW(Needed_Entry); 1228 nep->name = dynp->d_un.d_val; 1229 nep->obj = NULL; 1230 nep->next = NULL; 1231 1232 *needed_filtees_tail = nep; 1233 needed_filtees_tail = &nep->next; 1234 1235 if (obj->linkmap.l_refname == NULL) 1236 obj->linkmap.l_refname = (char *)dynp->d_un.d_val; 1237 } 1238 break; 1239 1240 case DT_AUXILIARY: 1241 if (!obj->rtld) { 1242 Needed_Entry *nep = NEW(Needed_Entry); 1243 nep->name = dynp->d_un.d_val; 1244 nep->obj = NULL; 1245 nep->next = NULL; 1246 1247 *needed_aux_filtees_tail = nep; 1248 needed_aux_filtees_tail = &nep->next; 1249 } 1250 break; 1251 1252 case DT_PLTGOT: 1253 obj->pltgot = (Elf_Addr *)(obj->relocbase + dynp->d_un.d_ptr); 1254 break; 1255 1256 case DT_TEXTREL: 1257 obj->textrel = true; 1258 break; 1259 1260 case DT_SYMBOLIC: 1261 obj->symbolic = true; 1262 break; 1263 1264 case DT_RPATH: 1265 /* 1266 * We have to wait until later to process this, because we 1267 * might not have gotten the address of the string table yet. 1268 */ 1269 *dyn_rpath = dynp; 1270 break; 1271 1272 case DT_SONAME: 1273 *dyn_soname = dynp; 1274 break; 1275 1276 case DT_RUNPATH: 1277 *dyn_runpath = dynp; 1278 break; 1279 1280 case DT_INIT: 1281 obj->init = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1282 break; 1283 1284 case DT_PREINIT_ARRAY: 1285 obj->preinit_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1286 break; 1287 1288 case DT_PREINIT_ARRAYSZ: 1289 obj->preinit_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1290 break; 1291 1292 case DT_INIT_ARRAY: 1293 obj->init_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1294 break; 1295 1296 case DT_INIT_ARRAYSZ: 1297 obj->init_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1298 break; 1299 1300 case DT_FINI: 1301 obj->fini = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1302 break; 1303 1304 case DT_FINI_ARRAY: 1305 obj->fini_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1306 break; 1307 1308 case DT_FINI_ARRAYSZ: 1309 obj->fini_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1310 break; 1311 1312 /* 1313 * Don't process DT_DEBUG on MIPS as the dynamic section 1314 * is mapped read-only. DT_MIPS_RLD_MAP is used instead. 1315 */ 1316 1317 #ifndef __mips__ 1318 case DT_DEBUG: 1319 if (!early) 1320 dbg("Filling in DT_DEBUG entry"); 1321 (__DECONST(Elf_Dyn *, dynp))->d_un.d_ptr = (Elf_Addr)&r_debug; 1322 break; 1323 #endif 1324 1325 case DT_FLAGS: 1326 if (dynp->d_un.d_val & DF_ORIGIN) 1327 obj->z_origin = true; 1328 if (dynp->d_un.d_val & DF_SYMBOLIC) 1329 obj->symbolic = true; 1330 if (dynp->d_un.d_val & DF_TEXTREL) 1331 obj->textrel = true; 1332 if (dynp->d_un.d_val & DF_BIND_NOW) 1333 obj->bind_now = true; 1334 if (dynp->d_un.d_val & DF_STATIC_TLS) 1335 obj->static_tls = true; 1336 break; 1337 #ifdef __mips__ 1338 case DT_MIPS_LOCAL_GOTNO: 1339 obj->local_gotno = dynp->d_un.d_val; 1340 break; 1341 1342 case DT_MIPS_SYMTABNO: 1343 obj->symtabno = dynp->d_un.d_val; 1344 break; 1345 1346 case DT_MIPS_GOTSYM: 1347 obj->gotsym = dynp->d_un.d_val; 1348 break; 1349 1350 case DT_MIPS_RLD_MAP: 1351 *((Elf_Addr *)(dynp->d_un.d_ptr)) = (Elf_Addr) &r_debug; 1352 break; 1353 1354 case DT_MIPS_RLD_MAP_REL: 1355 // The MIPS_RLD_MAP_REL tag stores the offset to the .rld_map 1356 // section relative to the address of the tag itself. 1357 *((Elf_Addr *)(__DECONST(char*, dynp) + dynp->d_un.d_val)) = 1358 (Elf_Addr) &r_debug; 1359 break; 1360 1361 case DT_MIPS_PLTGOT: 1362 obj->mips_pltgot = (Elf_Addr *)(obj->relocbase + 1363 dynp->d_un.d_ptr); 1364 break; 1365 1366 #endif 1367 1368 #ifdef __powerpc__ 1369 #ifdef __powerpc64__ 1370 case DT_PPC64_GLINK: 1371 obj->glink = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1372 break; 1373 #else 1374 case DT_PPC_GOT: 1375 obj->gotptr = (Elf_Addr *)(obj->relocbase + dynp->d_un.d_ptr); 1376 break; 1377 #endif 1378 #endif 1379 1380 case DT_FLAGS_1: 1381 if (dynp->d_un.d_val & DF_1_NOOPEN) 1382 obj->z_noopen = true; 1383 if (dynp->d_un.d_val & DF_1_ORIGIN) 1384 obj->z_origin = true; 1385 if (dynp->d_un.d_val & DF_1_GLOBAL) 1386 obj->z_global = true; 1387 if (dynp->d_un.d_val & DF_1_BIND_NOW) 1388 obj->bind_now = true; 1389 if (dynp->d_un.d_val & DF_1_NODELETE) 1390 obj->z_nodelete = true; 1391 if (dynp->d_un.d_val & DF_1_LOADFLTR) 1392 obj->z_loadfltr = true; 1393 if (dynp->d_un.d_val & DF_1_INTERPOSE) 1394 obj->z_interpose = true; 1395 if (dynp->d_un.d_val & DF_1_NODEFLIB) 1396 obj->z_nodeflib = true; 1397 if (dynp->d_un.d_val & DF_1_PIE) 1398 obj->z_pie = true; 1399 break; 1400 1401 default: 1402 if (!early) { 1403 dbg("Ignoring d_tag %ld = %#lx", (long)dynp->d_tag, 1404 (long)dynp->d_tag); 1405 } 1406 break; 1407 } 1408 } 1409 1410 obj->traced = false; 1411 1412 if (plttype == DT_RELA) { 1413 obj->pltrela = (const Elf_Rela *) obj->pltrel; 1414 obj->pltrel = NULL; 1415 obj->pltrelasize = obj->pltrelsize; 1416 obj->pltrelsize = 0; 1417 } 1418 1419 /* Determine size of dynsym table (equal to nchains of sysv hash) */ 1420 if (obj->valid_hash_sysv) 1421 obj->dynsymcount = obj->nchains; 1422 else if (obj->valid_hash_gnu) { 1423 obj->dynsymcount = 0; 1424 for (bkt = 0; bkt < obj->nbuckets_gnu; bkt++) { 1425 if (obj->buckets_gnu[bkt] == 0) 1426 continue; 1427 hashval = &obj->chain_zero_gnu[obj->buckets_gnu[bkt]]; 1428 do 1429 obj->dynsymcount++; 1430 while ((*hashval++ & 1u) == 0); 1431 } 1432 obj->dynsymcount += obj->symndx_gnu; 1433 } 1434 1435 if (obj->linkmap.l_refname != NULL) 1436 obj->linkmap.l_refname = obj->strtab + (unsigned long)obj-> 1437 linkmap.l_refname; 1438 } 1439 1440 static bool 1441 obj_resolve_origin(Obj_Entry *obj) 1442 { 1443 1444 if (obj->origin_path != NULL) 1445 return (true); 1446 obj->origin_path = xmalloc(PATH_MAX); 1447 return (rtld_dirname_abs(obj->path, obj->origin_path) != -1); 1448 } 1449 1450 static bool 1451 digest_dynamic2(Obj_Entry *obj, const Elf_Dyn *dyn_rpath, 1452 const Elf_Dyn *dyn_soname, const Elf_Dyn *dyn_runpath) 1453 { 1454 1455 if (obj->z_origin && !obj_resolve_origin(obj)) 1456 return (false); 1457 1458 if (dyn_runpath != NULL) { 1459 obj->runpath = (const char *)obj->strtab + dyn_runpath->d_un.d_val; 1460 obj->runpath = origin_subst(obj, obj->runpath); 1461 } else if (dyn_rpath != NULL) { 1462 obj->rpath = (const char *)obj->strtab + dyn_rpath->d_un.d_val; 1463 obj->rpath = origin_subst(obj, obj->rpath); 1464 } 1465 if (dyn_soname != NULL) 1466 object_add_name(obj, obj->strtab + dyn_soname->d_un.d_val); 1467 return (true); 1468 } 1469 1470 static bool 1471 digest_dynamic(Obj_Entry *obj, int early) 1472 { 1473 const Elf_Dyn *dyn_rpath; 1474 const Elf_Dyn *dyn_soname; 1475 const Elf_Dyn *dyn_runpath; 1476 1477 digest_dynamic1(obj, early, &dyn_rpath, &dyn_soname, &dyn_runpath); 1478 return (digest_dynamic2(obj, dyn_rpath, dyn_soname, dyn_runpath)); 1479 } 1480 1481 /* 1482 * Process a shared object's program header. This is used only for the 1483 * main program, when the kernel has already loaded the main program 1484 * into memory before calling the dynamic linker. It creates and 1485 * returns an Obj_Entry structure. 1486 */ 1487 static Obj_Entry * 1488 digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path) 1489 { 1490 Obj_Entry *obj; 1491 const Elf_Phdr *phlimit = phdr + phnum; 1492 const Elf_Phdr *ph; 1493 Elf_Addr note_start, note_end; 1494 int nsegs = 0; 1495 1496 obj = obj_new(); 1497 for (ph = phdr; ph < phlimit; ph++) { 1498 if (ph->p_type != PT_PHDR) 1499 continue; 1500 1501 obj->phdr = phdr; 1502 obj->phsize = ph->p_memsz; 1503 obj->relocbase = __DECONST(char *, phdr) - ph->p_vaddr; 1504 break; 1505 } 1506 1507 obj->stack_flags = PF_X | PF_R | PF_W; 1508 1509 for (ph = phdr; ph < phlimit; ph++) { 1510 switch (ph->p_type) { 1511 1512 case PT_INTERP: 1513 obj->interp = (const char *)(ph->p_vaddr + obj->relocbase); 1514 break; 1515 1516 case PT_LOAD: 1517 if (nsegs == 0) { /* First load segment */ 1518 obj->vaddrbase = trunc_page(ph->p_vaddr); 1519 obj->mapbase = obj->vaddrbase + obj->relocbase; 1520 } else { /* Last load segment */ 1521 obj->mapsize = round_page(ph->p_vaddr + ph->p_memsz) - 1522 obj->vaddrbase; 1523 } 1524 nsegs++; 1525 break; 1526 1527 case PT_DYNAMIC: 1528 obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + obj->relocbase); 1529 break; 1530 1531 case PT_TLS: 1532 obj->tlsindex = 1; 1533 obj->tlssize = ph->p_memsz; 1534 obj->tlsalign = ph->p_align; 1535 obj->tlsinitsize = ph->p_filesz; 1536 obj->tlsinit = (void*)(ph->p_vaddr + obj->relocbase); 1537 obj->tlspoffset = ph->p_offset; 1538 break; 1539 1540 case PT_GNU_STACK: 1541 obj->stack_flags = ph->p_flags; 1542 break; 1543 1544 case PT_GNU_RELRO: 1545 obj->relro_page = obj->relocbase + trunc_page(ph->p_vaddr); 1546 obj->relro_size = round_page(ph->p_memsz); 1547 break; 1548 1549 case PT_NOTE: 1550 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; 1551 note_end = note_start + ph->p_filesz; 1552 digest_notes(obj, note_start, note_end); 1553 break; 1554 } 1555 } 1556 if (nsegs < 1) { 1557 _rtld_error("%s: too few PT_LOAD segments", path); 1558 return NULL; 1559 } 1560 1561 obj->entry = entry; 1562 return obj; 1563 } 1564 1565 void 1566 digest_notes(Obj_Entry *obj, Elf_Addr note_start, Elf_Addr note_end) 1567 { 1568 const Elf_Note *note; 1569 const char *note_name; 1570 uintptr_t p; 1571 1572 for (note = (const Elf_Note *)note_start; (Elf_Addr)note < note_end; 1573 note = (const Elf_Note *)((const char *)(note + 1) + 1574 roundup2(note->n_namesz, sizeof(Elf32_Addr)) + 1575 roundup2(note->n_descsz, sizeof(Elf32_Addr)))) { 1576 if (note->n_namesz != sizeof(NOTE_FREEBSD_VENDOR) || 1577 note->n_descsz != sizeof(int32_t)) 1578 continue; 1579 if (note->n_type != NT_FREEBSD_ABI_TAG && 1580 note->n_type != NT_FREEBSD_FEATURE_CTL && 1581 note->n_type != NT_FREEBSD_NOINIT_TAG) 1582 continue; 1583 note_name = (const char *)(note + 1); 1584 if (strncmp(NOTE_FREEBSD_VENDOR, note_name, 1585 sizeof(NOTE_FREEBSD_VENDOR)) != 0) 1586 continue; 1587 switch (note->n_type) { 1588 case NT_FREEBSD_ABI_TAG: 1589 /* FreeBSD osrel note */ 1590 p = (uintptr_t)(note + 1); 1591 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1592 obj->osrel = *(const int32_t *)(p); 1593 dbg("note osrel %d", obj->osrel); 1594 break; 1595 case NT_FREEBSD_FEATURE_CTL: 1596 /* FreeBSD ABI feature control note */ 1597 p = (uintptr_t)(note + 1); 1598 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1599 obj->fctl0 = *(const uint32_t *)(p); 1600 dbg("note fctl0 %#x", obj->fctl0); 1601 break; 1602 case NT_FREEBSD_NOINIT_TAG: 1603 /* FreeBSD 'crt does not call init' note */ 1604 obj->crt_no_init = true; 1605 dbg("note crt_no_init"); 1606 break; 1607 } 1608 } 1609 } 1610 1611 static Obj_Entry * 1612 dlcheck(void *handle) 1613 { 1614 Obj_Entry *obj; 1615 1616 TAILQ_FOREACH(obj, &obj_list, next) { 1617 if (obj == (Obj_Entry *) handle) 1618 break; 1619 } 1620 1621 if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) { 1622 _rtld_error("Invalid shared object handle %p", handle); 1623 return NULL; 1624 } 1625 return obj; 1626 } 1627 1628 /* 1629 * If the given object is already in the donelist, return true. Otherwise 1630 * add the object to the list and return false. 1631 */ 1632 static bool 1633 donelist_check(DoneList *dlp, const Obj_Entry *obj) 1634 { 1635 unsigned int i; 1636 1637 for (i = 0; i < dlp->num_used; i++) 1638 if (dlp->objs[i] == obj) 1639 return true; 1640 /* 1641 * Our donelist allocation should always be sufficient. But if 1642 * our threads locking isn't working properly, more shared objects 1643 * could have been loaded since we allocated the list. That should 1644 * never happen, but we'll handle it properly just in case it does. 1645 */ 1646 if (dlp->num_used < dlp->num_alloc) 1647 dlp->objs[dlp->num_used++] = obj; 1648 return false; 1649 } 1650 1651 /* 1652 * Hash function for symbol table lookup. Don't even think about changing 1653 * this. It is specified by the System V ABI. 1654 */ 1655 unsigned long 1656 elf_hash(const char *name) 1657 { 1658 const unsigned char *p = (const unsigned char *) name; 1659 unsigned long h = 0; 1660 unsigned long g; 1661 1662 while (*p != '\0') { 1663 h = (h << 4) + *p++; 1664 if ((g = h & 0xf0000000) != 0) 1665 h ^= g >> 24; 1666 h &= ~g; 1667 } 1668 return h; 1669 } 1670 1671 /* 1672 * The GNU hash function is the Daniel J. Bernstein hash clipped to 32 bits 1673 * unsigned in case it's implemented with a wider type. 1674 */ 1675 static uint32_t 1676 gnu_hash(const char *s) 1677 { 1678 uint32_t h; 1679 unsigned char c; 1680 1681 h = 5381; 1682 for (c = *s; c != '\0'; c = *++s) 1683 h = h * 33 + c; 1684 return (h & 0xffffffff); 1685 } 1686 1687 1688 /* 1689 * Find the library with the given name, and return its full pathname. 1690 * The returned string is dynamically allocated. Generates an error 1691 * message and returns NULL if the library cannot be found. 1692 * 1693 * If the second argument is non-NULL, then it refers to an already- 1694 * loaded shared object, whose library search path will be searched. 1695 * 1696 * If a library is successfully located via LD_LIBRARY_PATH_FDS, its 1697 * descriptor (which is close-on-exec) will be passed out via the third 1698 * argument. 1699 * 1700 * The search order is: 1701 * DT_RPATH in the referencing file _unless_ DT_RUNPATH is present (1) 1702 * DT_RPATH of the main object if DSO without defined DT_RUNPATH (1) 1703 * LD_LIBRARY_PATH 1704 * DT_RUNPATH in the referencing file 1705 * ldconfig hints (if -z nodefaultlib, filter out default library directories 1706 * from list) 1707 * /lib:/usr/lib _unless_ the referencing file is linked with -z nodefaultlib 1708 * 1709 * (1) Handled in digest_dynamic2 - rpath left NULL if runpath defined. 1710 */ 1711 static char * 1712 find_library(const char *xname, const Obj_Entry *refobj, int *fdp) 1713 { 1714 char *pathname, *refobj_path; 1715 const char *name; 1716 bool nodeflib, objgiven; 1717 1718 objgiven = refobj != NULL; 1719 1720 if (libmap_disable || !objgiven || 1721 (name = lm_find(refobj->path, xname)) == NULL) 1722 name = xname; 1723 1724 if (strchr(name, '/') != NULL) { /* Hard coded pathname */ 1725 if (name[0] != '/' && !trust) { 1726 _rtld_error("Absolute pathname required " 1727 "for shared object \"%s\"", name); 1728 return (NULL); 1729 } 1730 return (origin_subst(__DECONST(Obj_Entry *, refobj), 1731 __DECONST(char *, name))); 1732 } 1733 1734 dbg(" Searching for \"%s\"", name); 1735 refobj_path = objgiven ? refobj->path : NULL; 1736 1737 /* 1738 * If refobj->rpath != NULL, then refobj->runpath is NULL. Fall 1739 * back to pre-conforming behaviour if user requested so with 1740 * LD_LIBRARY_PATH_RPATH environment variable and ignore -z 1741 * nodeflib. 1742 */ 1743 if (objgiven && refobj->rpath != NULL && ld_library_path_rpath) { 1744 pathname = search_library_path(name, ld_library_path, 1745 refobj_path, fdp); 1746 if (pathname != NULL) 1747 return (pathname); 1748 if (refobj != NULL) { 1749 pathname = search_library_path(name, refobj->rpath, 1750 refobj_path, fdp); 1751 if (pathname != NULL) 1752 return (pathname); 1753 } 1754 pathname = search_library_pathfds(name, ld_library_dirs, fdp); 1755 if (pathname != NULL) 1756 return (pathname); 1757 pathname = search_library_path(name, gethints(false), 1758 refobj_path, fdp); 1759 if (pathname != NULL) 1760 return (pathname); 1761 pathname = search_library_path(name, ld_standard_library_path, 1762 refobj_path, fdp); 1763 if (pathname != NULL) 1764 return (pathname); 1765 } else { 1766 nodeflib = objgiven ? refobj->z_nodeflib : false; 1767 if (objgiven) { 1768 pathname = search_library_path(name, refobj->rpath, 1769 refobj->path, fdp); 1770 if (pathname != NULL) 1771 return (pathname); 1772 } 1773 if (objgiven && refobj->runpath == NULL && refobj != obj_main) { 1774 pathname = search_library_path(name, obj_main->rpath, 1775 refobj_path, fdp); 1776 if (pathname != NULL) 1777 return (pathname); 1778 } 1779 pathname = search_library_path(name, ld_library_path, 1780 refobj_path, fdp); 1781 if (pathname != NULL) 1782 return (pathname); 1783 if (objgiven) { 1784 pathname = search_library_path(name, refobj->runpath, 1785 refobj_path, fdp); 1786 if (pathname != NULL) 1787 return (pathname); 1788 } 1789 pathname = search_library_pathfds(name, ld_library_dirs, fdp); 1790 if (pathname != NULL) 1791 return (pathname); 1792 pathname = search_library_path(name, gethints(nodeflib), 1793 refobj_path, fdp); 1794 if (pathname != NULL) 1795 return (pathname); 1796 if (objgiven && !nodeflib) { 1797 pathname = search_library_path(name, 1798 ld_standard_library_path, refobj_path, fdp); 1799 if (pathname != NULL) 1800 return (pathname); 1801 } 1802 } 1803 1804 if (objgiven && refobj->path != NULL) { 1805 _rtld_error("Shared object \"%s\" not found, " 1806 "required by \"%s\"", name, basename(refobj->path)); 1807 } else { 1808 _rtld_error("Shared object \"%s\" not found", name); 1809 } 1810 return (NULL); 1811 } 1812 1813 /* 1814 * Given a symbol number in a referencing object, find the corresponding 1815 * definition of the symbol. Returns a pointer to the symbol, or NULL if 1816 * no definition was found. Returns a pointer to the Obj_Entry of the 1817 * defining object via the reference parameter DEFOBJ_OUT. 1818 */ 1819 const Elf_Sym * 1820 find_symdef(unsigned long symnum, const Obj_Entry *refobj, 1821 const Obj_Entry **defobj_out, int flags, SymCache *cache, 1822 RtldLockState *lockstate) 1823 { 1824 const Elf_Sym *ref; 1825 const Elf_Sym *def; 1826 const Obj_Entry *defobj; 1827 const Ver_Entry *ve; 1828 SymLook req; 1829 const char *name; 1830 int res; 1831 1832 /* 1833 * If we have already found this symbol, get the information from 1834 * the cache. 1835 */ 1836 if (symnum >= refobj->dynsymcount) 1837 return NULL; /* Bad object */ 1838 if (cache != NULL && cache[symnum].sym != NULL) { 1839 *defobj_out = cache[symnum].obj; 1840 return cache[symnum].sym; 1841 } 1842 1843 ref = refobj->symtab + symnum; 1844 name = refobj->strtab + ref->st_name; 1845 def = NULL; 1846 defobj = NULL; 1847 ve = NULL; 1848 1849 /* 1850 * We don't have to do a full scale lookup if the symbol is local. 1851 * We know it will bind to the instance in this load module; to 1852 * which we already have a pointer (ie ref). By not doing a lookup, 1853 * we not only improve performance, but it also avoids unresolvable 1854 * symbols when local symbols are not in the hash table. This has 1855 * been seen with the ia64 toolchain. 1856 */ 1857 if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) { 1858 if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) { 1859 _rtld_error("%s: Bogus symbol table entry %lu", refobj->path, 1860 symnum); 1861 } 1862 symlook_init(&req, name); 1863 req.flags = flags; 1864 ve = req.ventry = fetch_ventry(refobj, symnum); 1865 req.lockstate = lockstate; 1866 res = symlook_default(&req, refobj); 1867 if (res == 0) { 1868 def = req.sym_out; 1869 defobj = req.defobj_out; 1870 } 1871 } else { 1872 def = ref; 1873 defobj = refobj; 1874 } 1875 1876 /* 1877 * If we found no definition and the reference is weak, treat the 1878 * symbol as having the value zero. 1879 */ 1880 if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) { 1881 def = &sym_zero; 1882 defobj = obj_main; 1883 } 1884 1885 if (def != NULL) { 1886 *defobj_out = defobj; 1887 /* Record the information in the cache to avoid subsequent lookups. */ 1888 if (cache != NULL) { 1889 cache[symnum].sym = def; 1890 cache[symnum].obj = defobj; 1891 } 1892 } else { 1893 if (refobj != &obj_rtld) 1894 _rtld_error("%s: Undefined symbol \"%s%s%s\"", refobj->path, name, 1895 ve != NULL ? "@" : "", ve != NULL ? ve->name : ""); 1896 } 1897 return def; 1898 } 1899 1900 /* 1901 * Return the search path from the ldconfig hints file, reading it if 1902 * necessary. If nostdlib is true, then the default search paths are 1903 * not added to result. 1904 * 1905 * Returns NULL if there are problems with the hints file, 1906 * or if the search path there is empty. 1907 */ 1908 static const char * 1909 gethints(bool nostdlib) 1910 { 1911 static char *filtered_path; 1912 static const char *hints; 1913 static struct elfhints_hdr hdr; 1914 struct fill_search_info_args sargs, hargs; 1915 struct dl_serinfo smeta, hmeta, *SLPinfo, *hintinfo; 1916 struct dl_serpath *SLPpath, *hintpath; 1917 char *p; 1918 struct stat hint_stat; 1919 unsigned int SLPndx, hintndx, fndx, fcount; 1920 int fd; 1921 size_t flen; 1922 uint32_t dl; 1923 bool skip; 1924 1925 /* First call, read the hints file */ 1926 if (hints == NULL) { 1927 /* Keep from trying again in case the hints file is bad. */ 1928 hints = ""; 1929 1930 if ((fd = open(ld_elf_hints_path, O_RDONLY | O_CLOEXEC)) == -1) 1931 return (NULL); 1932 1933 /* 1934 * Check of hdr.dirlistlen value against type limit 1935 * intends to pacify static analyzers. Further 1936 * paranoia leads to checks that dirlist is fully 1937 * contained in the file range. 1938 */ 1939 if (read(fd, &hdr, sizeof hdr) != sizeof hdr || 1940 hdr.magic != ELFHINTS_MAGIC || 1941 hdr.version != 1 || hdr.dirlistlen > UINT_MAX / 2 || 1942 fstat(fd, &hint_stat) == -1) { 1943 cleanup1: 1944 close(fd); 1945 hdr.dirlistlen = 0; 1946 return (NULL); 1947 } 1948 dl = hdr.strtab; 1949 if (dl + hdr.dirlist < dl) 1950 goto cleanup1; 1951 dl += hdr.dirlist; 1952 if (dl + hdr.dirlistlen < dl) 1953 goto cleanup1; 1954 dl += hdr.dirlistlen; 1955 if (dl > hint_stat.st_size) 1956 goto cleanup1; 1957 p = xmalloc(hdr.dirlistlen + 1); 1958 if (pread(fd, p, hdr.dirlistlen + 1, 1959 hdr.strtab + hdr.dirlist) != (ssize_t)hdr.dirlistlen + 1 || 1960 p[hdr.dirlistlen] != '\0') { 1961 free(p); 1962 goto cleanup1; 1963 } 1964 hints = p; 1965 close(fd); 1966 } 1967 1968 /* 1969 * If caller agreed to receive list which includes the default 1970 * paths, we are done. Otherwise, if we still did not 1971 * calculated filtered result, do it now. 1972 */ 1973 if (!nostdlib) 1974 return (hints[0] != '\0' ? hints : NULL); 1975 if (filtered_path != NULL) 1976 goto filt_ret; 1977 1978 /* 1979 * Obtain the list of all configured search paths, and the 1980 * list of the default paths. 1981 * 1982 * First estimate the size of the results. 1983 */ 1984 smeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 1985 smeta.dls_cnt = 0; 1986 hmeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 1987 hmeta.dls_cnt = 0; 1988 1989 sargs.request = RTLD_DI_SERINFOSIZE; 1990 sargs.serinfo = &smeta; 1991 hargs.request = RTLD_DI_SERINFOSIZE; 1992 hargs.serinfo = &hmeta; 1993 1994 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 1995 &sargs); 1996 path_enumerate(hints, fill_search_info, NULL, &hargs); 1997 1998 SLPinfo = xmalloc(smeta.dls_size); 1999 hintinfo = xmalloc(hmeta.dls_size); 2000 2001 /* 2002 * Next fetch both sets of paths. 2003 */ 2004 sargs.request = RTLD_DI_SERINFO; 2005 sargs.serinfo = SLPinfo; 2006 sargs.serpath = &SLPinfo->dls_serpath[0]; 2007 sargs.strspace = (char *)&SLPinfo->dls_serpath[smeta.dls_cnt]; 2008 2009 hargs.request = RTLD_DI_SERINFO; 2010 hargs.serinfo = hintinfo; 2011 hargs.serpath = &hintinfo->dls_serpath[0]; 2012 hargs.strspace = (char *)&hintinfo->dls_serpath[hmeta.dls_cnt]; 2013 2014 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 2015 &sargs); 2016 path_enumerate(hints, fill_search_info, NULL, &hargs); 2017 2018 /* 2019 * Now calculate the difference between two sets, by excluding 2020 * standard paths from the full set. 2021 */ 2022 fndx = 0; 2023 fcount = 0; 2024 filtered_path = xmalloc(hdr.dirlistlen + 1); 2025 hintpath = &hintinfo->dls_serpath[0]; 2026 for (hintndx = 0; hintndx < hmeta.dls_cnt; hintndx++, hintpath++) { 2027 skip = false; 2028 SLPpath = &SLPinfo->dls_serpath[0]; 2029 /* 2030 * Check each standard path against current. 2031 */ 2032 for (SLPndx = 0; SLPndx < smeta.dls_cnt; SLPndx++, SLPpath++) { 2033 /* matched, skip the path */ 2034 if (!strcmp(hintpath->dls_name, SLPpath->dls_name)) { 2035 skip = true; 2036 break; 2037 } 2038 } 2039 if (skip) 2040 continue; 2041 /* 2042 * Not matched against any standard path, add the path 2043 * to result. Separate consequtive paths with ':'. 2044 */ 2045 if (fcount > 0) { 2046 filtered_path[fndx] = ':'; 2047 fndx++; 2048 } 2049 fcount++; 2050 flen = strlen(hintpath->dls_name); 2051 strncpy((filtered_path + fndx), hintpath->dls_name, flen); 2052 fndx += flen; 2053 } 2054 filtered_path[fndx] = '\0'; 2055 2056 free(SLPinfo); 2057 free(hintinfo); 2058 2059 filt_ret: 2060 return (filtered_path[0] != '\0' ? filtered_path : NULL); 2061 } 2062 2063 static void 2064 init_dag(Obj_Entry *root) 2065 { 2066 const Needed_Entry *needed; 2067 const Objlist_Entry *elm; 2068 DoneList donelist; 2069 2070 if (root->dag_inited) 2071 return; 2072 donelist_init(&donelist); 2073 2074 /* Root object belongs to own DAG. */ 2075 objlist_push_tail(&root->dldags, root); 2076 objlist_push_tail(&root->dagmembers, root); 2077 donelist_check(&donelist, root); 2078 2079 /* 2080 * Add dependencies of root object to DAG in breadth order 2081 * by exploiting the fact that each new object get added 2082 * to the tail of the dagmembers list. 2083 */ 2084 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2085 for (needed = elm->obj->needed; needed != NULL; needed = needed->next) { 2086 if (needed->obj == NULL || donelist_check(&donelist, needed->obj)) 2087 continue; 2088 objlist_push_tail(&needed->obj->dldags, root); 2089 objlist_push_tail(&root->dagmembers, needed->obj); 2090 } 2091 } 2092 root->dag_inited = true; 2093 } 2094 2095 static void 2096 init_marker(Obj_Entry *marker) 2097 { 2098 2099 bzero(marker, sizeof(*marker)); 2100 marker->marker = true; 2101 } 2102 2103 Obj_Entry * 2104 globallist_curr(const Obj_Entry *obj) 2105 { 2106 2107 for (;;) { 2108 if (obj == NULL) 2109 return (NULL); 2110 if (!obj->marker) 2111 return (__DECONST(Obj_Entry *, obj)); 2112 obj = TAILQ_PREV(obj, obj_entry_q, next); 2113 } 2114 } 2115 2116 Obj_Entry * 2117 globallist_next(const Obj_Entry *obj) 2118 { 2119 2120 for (;;) { 2121 obj = TAILQ_NEXT(obj, next); 2122 if (obj == NULL) 2123 return (NULL); 2124 if (!obj->marker) 2125 return (__DECONST(Obj_Entry *, obj)); 2126 } 2127 } 2128 2129 /* Prevent the object from being unmapped while the bind lock is dropped. */ 2130 static void 2131 hold_object(Obj_Entry *obj) 2132 { 2133 2134 obj->holdcount++; 2135 } 2136 2137 static void 2138 unhold_object(Obj_Entry *obj) 2139 { 2140 2141 assert(obj->holdcount > 0); 2142 if (--obj->holdcount == 0 && obj->unholdfree) 2143 release_object(obj); 2144 } 2145 2146 static void 2147 process_z(Obj_Entry *root) 2148 { 2149 const Objlist_Entry *elm; 2150 Obj_Entry *obj; 2151 2152 /* 2153 * Walk over object DAG and process every dependent object 2154 * that is marked as DF_1_NODELETE or DF_1_GLOBAL. They need 2155 * to grow their own DAG. 2156 * 2157 * For DF_1_GLOBAL, DAG is required for symbol lookups in 2158 * symlook_global() to work. 2159 * 2160 * For DF_1_NODELETE, the DAG should have its reference upped. 2161 */ 2162 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2163 obj = elm->obj; 2164 if (obj == NULL) 2165 continue; 2166 if (obj->z_nodelete && !obj->ref_nodel) { 2167 dbg("obj %s -z nodelete", obj->path); 2168 init_dag(obj); 2169 ref_dag(obj); 2170 obj->ref_nodel = true; 2171 } 2172 if (obj->z_global && objlist_find(&list_global, obj) == NULL) { 2173 dbg("obj %s -z global", obj->path); 2174 objlist_push_tail(&list_global, obj); 2175 init_dag(obj); 2176 } 2177 } 2178 } 2179 2180 static void 2181 parse_rtld_phdr(Obj_Entry *obj) 2182 { 2183 const Elf_Phdr *ph; 2184 Elf_Addr note_start, note_end; 2185 2186 obj->stack_flags = PF_X | PF_R | PF_W; 2187 for (ph = obj->phdr; (const char *)ph < (const char *)obj->phdr + 2188 obj->phsize; ph++) { 2189 switch (ph->p_type) { 2190 case PT_GNU_STACK: 2191 obj->stack_flags = ph->p_flags; 2192 break; 2193 case PT_GNU_RELRO: 2194 obj->relro_page = obj->relocbase + 2195 trunc_page(ph->p_vaddr); 2196 obj->relro_size = round_page(ph->p_memsz); 2197 break; 2198 case PT_NOTE: 2199 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; 2200 note_end = note_start + ph->p_filesz; 2201 digest_notes(obj, note_start, note_end); 2202 break; 2203 } 2204 } 2205 } 2206 2207 /* 2208 * Initialize the dynamic linker. The argument is the address at which 2209 * the dynamic linker has been mapped into memory. The primary task of 2210 * this function is to relocate the dynamic linker. 2211 */ 2212 static void 2213 init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info) 2214 { 2215 Obj_Entry objtmp; /* Temporary rtld object */ 2216 const Elf_Ehdr *ehdr; 2217 const Elf_Dyn *dyn_rpath; 2218 const Elf_Dyn *dyn_soname; 2219 const Elf_Dyn *dyn_runpath; 2220 2221 #ifdef RTLD_INIT_PAGESIZES_EARLY 2222 /* The page size is required by the dynamic memory allocator. */ 2223 init_pagesizes(aux_info); 2224 #endif 2225 2226 /* 2227 * Conjure up an Obj_Entry structure for the dynamic linker. 2228 * 2229 * The "path" member can't be initialized yet because string constants 2230 * cannot yet be accessed. Below we will set it correctly. 2231 */ 2232 memset(&objtmp, 0, sizeof(objtmp)); 2233 objtmp.path = NULL; 2234 objtmp.rtld = true; 2235 objtmp.mapbase = mapbase; 2236 #ifdef PIC 2237 objtmp.relocbase = mapbase; 2238 #endif 2239 2240 objtmp.dynamic = rtld_dynamic(&objtmp); 2241 digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname, &dyn_runpath); 2242 assert(objtmp.needed == NULL); 2243 #if !defined(__mips__) 2244 /* MIPS has a bogus DT_TEXTREL. */ 2245 assert(!objtmp.textrel); 2246 #endif 2247 /* 2248 * Temporarily put the dynamic linker entry into the object list, so 2249 * that symbols can be found. 2250 */ 2251 relocate_objects(&objtmp, true, &objtmp, 0, NULL); 2252 2253 ehdr = (Elf_Ehdr *)mapbase; 2254 objtmp.phdr = (Elf_Phdr *)((char *)mapbase + ehdr->e_phoff); 2255 objtmp.phsize = ehdr->e_phnum * sizeof(objtmp.phdr[0]); 2256 2257 /* Initialize the object list. */ 2258 TAILQ_INIT(&obj_list); 2259 2260 /* Now that non-local variables can be accesses, copy out obj_rtld. */ 2261 memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld)); 2262 2263 #ifndef RTLD_INIT_PAGESIZES_EARLY 2264 /* The page size is required by the dynamic memory allocator. */ 2265 init_pagesizes(aux_info); 2266 #endif 2267 2268 if (aux_info[AT_OSRELDATE] != NULL) 2269 osreldate = aux_info[AT_OSRELDATE]->a_un.a_val; 2270 2271 digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname, dyn_runpath); 2272 2273 /* Replace the path with a dynamically allocated copy. */ 2274 obj_rtld.path = xstrdup(ld_path_rtld); 2275 2276 parse_rtld_phdr(&obj_rtld); 2277 obj_enforce_relro(&obj_rtld); 2278 2279 r_debug.r_version = R_DEBUG_VERSION; 2280 r_debug.r_brk = r_debug_state; 2281 r_debug.r_state = RT_CONSISTENT; 2282 r_debug.r_ldbase = obj_rtld.relocbase; 2283 } 2284 2285 /* 2286 * Retrieve the array of supported page sizes. The kernel provides the page 2287 * sizes in increasing order. 2288 */ 2289 static void 2290 init_pagesizes(Elf_Auxinfo **aux_info) 2291 { 2292 static size_t psa[MAXPAGESIZES]; 2293 int mib[2]; 2294 size_t len, size; 2295 2296 if (aux_info[AT_PAGESIZES] != NULL && aux_info[AT_PAGESIZESLEN] != 2297 NULL) { 2298 size = aux_info[AT_PAGESIZESLEN]->a_un.a_val; 2299 pagesizes = aux_info[AT_PAGESIZES]->a_un.a_ptr; 2300 } else { 2301 len = 2; 2302 if (sysctlnametomib("hw.pagesizes", mib, &len) == 0) 2303 size = sizeof(psa); 2304 else { 2305 /* As a fallback, retrieve the base page size. */ 2306 size = sizeof(psa[0]); 2307 if (aux_info[AT_PAGESZ] != NULL) { 2308 psa[0] = aux_info[AT_PAGESZ]->a_un.a_val; 2309 goto psa_filled; 2310 } else { 2311 mib[0] = CTL_HW; 2312 mib[1] = HW_PAGESIZE; 2313 len = 2; 2314 } 2315 } 2316 if (sysctl(mib, len, psa, &size, NULL, 0) == -1) { 2317 _rtld_error("sysctl for hw.pagesize(s) failed"); 2318 rtld_die(); 2319 } 2320 psa_filled: 2321 pagesizes = psa; 2322 } 2323 npagesizes = size / sizeof(pagesizes[0]); 2324 /* Discard any invalid entries at the end of the array. */ 2325 while (npagesizes > 0 && pagesizes[npagesizes - 1] == 0) 2326 npagesizes--; 2327 } 2328 2329 /* 2330 * Add the init functions from a needed object list (and its recursive 2331 * needed objects) to "list". This is not used directly; it is a helper 2332 * function for initlist_add_objects(). The write lock must be held 2333 * when this function is called. 2334 */ 2335 static void 2336 initlist_add_neededs(Needed_Entry *needed, Objlist *list) 2337 { 2338 /* Recursively process the successor needed objects. */ 2339 if (needed->next != NULL) 2340 initlist_add_neededs(needed->next, list); 2341 2342 /* Process the current needed object. */ 2343 if (needed->obj != NULL) 2344 initlist_add_objects(needed->obj, needed->obj, list); 2345 } 2346 2347 /* 2348 * Scan all of the DAGs rooted in the range of objects from "obj" to 2349 * "tail" and add their init functions to "list". This recurses over 2350 * the DAGs and ensure the proper init ordering such that each object's 2351 * needed libraries are initialized before the object itself. At the 2352 * same time, this function adds the objects to the global finalization 2353 * list "list_fini" in the opposite order. The write lock must be 2354 * held when this function is called. 2355 */ 2356 static void 2357 initlist_add_objects(Obj_Entry *obj, Obj_Entry *tail, Objlist *list) 2358 { 2359 Obj_Entry *nobj; 2360 2361 if (obj->init_scanned || obj->init_done) 2362 return; 2363 obj->init_scanned = true; 2364 2365 /* Recursively process the successor objects. */ 2366 nobj = globallist_next(obj); 2367 if (nobj != NULL && obj != tail) 2368 initlist_add_objects(nobj, tail, list); 2369 2370 /* Recursively process the needed objects. */ 2371 if (obj->needed != NULL) 2372 initlist_add_neededs(obj->needed, list); 2373 if (obj->needed_filtees != NULL) 2374 initlist_add_neededs(obj->needed_filtees, list); 2375 if (obj->needed_aux_filtees != NULL) 2376 initlist_add_neededs(obj->needed_aux_filtees, list); 2377 2378 /* Add the object to the init list. */ 2379 objlist_push_tail(list, obj); 2380 2381 /* Add the object to the global fini list in the reverse order. */ 2382 if ((obj->fini != (Elf_Addr)NULL || obj->fini_array != (Elf_Addr)NULL) 2383 && !obj->on_fini_list) { 2384 objlist_push_head(&list_fini, obj); 2385 obj->on_fini_list = true; 2386 } 2387 } 2388 2389 #ifndef FPTR_TARGET 2390 #define FPTR_TARGET(f) ((Elf_Addr) (f)) 2391 #endif 2392 2393 static void 2394 free_needed_filtees(Needed_Entry *n, RtldLockState *lockstate) 2395 { 2396 Needed_Entry *needed, *needed1; 2397 2398 for (needed = n; needed != NULL; needed = needed->next) { 2399 if (needed->obj != NULL) { 2400 dlclose_locked(needed->obj, lockstate); 2401 needed->obj = NULL; 2402 } 2403 } 2404 for (needed = n; needed != NULL; needed = needed1) { 2405 needed1 = needed->next; 2406 free(needed); 2407 } 2408 } 2409 2410 static void 2411 unload_filtees(Obj_Entry *obj, RtldLockState *lockstate) 2412 { 2413 2414 free_needed_filtees(obj->needed_filtees, lockstate); 2415 obj->needed_filtees = NULL; 2416 free_needed_filtees(obj->needed_aux_filtees, lockstate); 2417 obj->needed_aux_filtees = NULL; 2418 obj->filtees_loaded = false; 2419 } 2420 2421 static void 2422 load_filtee1(Obj_Entry *obj, Needed_Entry *needed, int flags, 2423 RtldLockState *lockstate) 2424 { 2425 2426 for (; needed != NULL; needed = needed->next) { 2427 needed->obj = dlopen_object(obj->strtab + needed->name, -1, obj, 2428 flags, ((ld_loadfltr || obj->z_loadfltr) ? RTLD_NOW : RTLD_LAZY) | 2429 RTLD_LOCAL, lockstate); 2430 } 2431 } 2432 2433 static void 2434 load_filtees(Obj_Entry *obj, int flags, RtldLockState *lockstate) 2435 { 2436 2437 lock_restart_for_upgrade(lockstate); 2438 if (!obj->filtees_loaded) { 2439 load_filtee1(obj, obj->needed_filtees, flags, lockstate); 2440 load_filtee1(obj, obj->needed_aux_filtees, flags, lockstate); 2441 obj->filtees_loaded = true; 2442 } 2443 } 2444 2445 static int 2446 process_needed(Obj_Entry *obj, Needed_Entry *needed, int flags) 2447 { 2448 Obj_Entry *obj1; 2449 2450 for (; needed != NULL; needed = needed->next) { 2451 obj1 = needed->obj = load_object(obj->strtab + needed->name, -1, obj, 2452 flags & ~RTLD_LO_NOLOAD); 2453 if (obj1 == NULL && !ld_tracing && (flags & RTLD_LO_FILTEES) == 0) 2454 return (-1); 2455 } 2456 return (0); 2457 } 2458 2459 /* 2460 * Given a shared object, traverse its list of needed objects, and load 2461 * each of them. Returns 0 on success. Generates an error message and 2462 * returns -1 on failure. 2463 */ 2464 static int 2465 load_needed_objects(Obj_Entry *first, int flags) 2466 { 2467 Obj_Entry *obj; 2468 2469 for (obj = first; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 2470 if (obj->marker) 2471 continue; 2472 if (process_needed(obj, obj->needed, flags) == -1) 2473 return (-1); 2474 } 2475 return (0); 2476 } 2477 2478 static int 2479 load_preload_objects(char *p, bool isfd) 2480 { 2481 Obj_Entry *obj; 2482 static const char delim[] = " \t:;"; 2483 2484 if (p == NULL) 2485 return (0); 2486 2487 p += strspn(p, delim); 2488 while (*p != '\0') { 2489 const char *name; 2490 size_t len = strcspn(p, delim); 2491 char savech; 2492 int fd; 2493 2494 savech = p[len]; 2495 p[len] = '\0'; 2496 if (isfd) { 2497 name = NULL; 2498 fd = parse_integer(p); 2499 if (fd == -1) 2500 return (-1); 2501 } else { 2502 name = p; 2503 fd = -1; 2504 } 2505 2506 obj = load_object(name, fd, NULL, 0); 2507 if (obj == NULL) 2508 return (-1); /* XXX - cleanup */ 2509 obj->z_interpose = true; 2510 p[len] = savech; 2511 p += len; 2512 p += strspn(p, delim); 2513 } 2514 LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL); 2515 2516 return (0); 2517 } 2518 2519 static const char * 2520 printable_path(const char *path) 2521 { 2522 2523 return (path == NULL ? "<unknown>" : path); 2524 } 2525 2526 /* 2527 * Load a shared object into memory, if it is not already loaded. The 2528 * object may be specified by name or by user-supplied file descriptor 2529 * fd_u. In the later case, the fd_u descriptor is not closed, but its 2530 * duplicate is. 2531 * 2532 * Returns a pointer to the Obj_Entry for the object. Returns NULL 2533 * on failure. 2534 */ 2535 static Obj_Entry * 2536 load_object(const char *name, int fd_u, const Obj_Entry *refobj, int flags) 2537 { 2538 Obj_Entry *obj; 2539 int fd; 2540 struct stat sb; 2541 char *path; 2542 2543 fd = -1; 2544 if (name != NULL) { 2545 TAILQ_FOREACH(obj, &obj_list, next) { 2546 if (obj->marker || obj->doomed) 2547 continue; 2548 if (object_match_name(obj, name)) 2549 return (obj); 2550 } 2551 2552 path = find_library(name, refobj, &fd); 2553 if (path == NULL) 2554 return (NULL); 2555 } else 2556 path = NULL; 2557 2558 if (fd >= 0) { 2559 /* 2560 * search_library_pathfds() opens a fresh file descriptor for the 2561 * library, so there is no need to dup(). 2562 */ 2563 } else if (fd_u == -1) { 2564 /* 2565 * If we didn't find a match by pathname, or the name is not 2566 * supplied, open the file and check again by device and inode. 2567 * This avoids false mismatches caused by multiple links or ".." 2568 * in pathnames. 2569 * 2570 * To avoid a race, we open the file and use fstat() rather than 2571 * using stat(). 2572 */ 2573 if ((fd = open(path, O_RDONLY | O_CLOEXEC | O_VERIFY)) == -1) { 2574 _rtld_error("Cannot open \"%s\"", path); 2575 free(path); 2576 return (NULL); 2577 } 2578 } else { 2579 fd = fcntl(fd_u, F_DUPFD_CLOEXEC, 0); 2580 if (fd == -1) { 2581 _rtld_error("Cannot dup fd"); 2582 free(path); 2583 return (NULL); 2584 } 2585 } 2586 if (fstat(fd, &sb) == -1) { 2587 _rtld_error("Cannot fstat \"%s\"", printable_path(path)); 2588 close(fd); 2589 free(path); 2590 return NULL; 2591 } 2592 TAILQ_FOREACH(obj, &obj_list, next) { 2593 if (obj->marker || obj->doomed) 2594 continue; 2595 if (obj->ino == sb.st_ino && obj->dev == sb.st_dev) 2596 break; 2597 } 2598 if (obj != NULL && name != NULL) { 2599 object_add_name(obj, name); 2600 free(path); 2601 close(fd); 2602 return obj; 2603 } 2604 if (flags & RTLD_LO_NOLOAD) { 2605 free(path); 2606 close(fd); 2607 return (NULL); 2608 } 2609 2610 /* First use of this object, so we must map it in */ 2611 obj = do_load_object(fd, name, path, &sb, flags); 2612 if (obj == NULL) 2613 free(path); 2614 close(fd); 2615 2616 return obj; 2617 } 2618 2619 static Obj_Entry * 2620 do_load_object(int fd, const char *name, char *path, struct stat *sbp, 2621 int flags) 2622 { 2623 Obj_Entry *obj; 2624 struct statfs fs; 2625 2626 /* 2627 * but first, make sure that environment variables haven't been 2628 * used to circumvent the noexec flag on a filesystem. 2629 */ 2630 if (dangerous_ld_env) { 2631 if (fstatfs(fd, &fs) != 0) { 2632 _rtld_error("Cannot fstatfs \"%s\"", printable_path(path)); 2633 return NULL; 2634 } 2635 if (fs.f_flags & MNT_NOEXEC) { 2636 _rtld_error("Cannot execute objects on %s", fs.f_mntonname); 2637 return NULL; 2638 } 2639 } 2640 dbg("loading \"%s\"", printable_path(path)); 2641 obj = map_object(fd, printable_path(path), sbp); 2642 if (obj == NULL) 2643 return NULL; 2644 2645 /* 2646 * If DT_SONAME is present in the object, digest_dynamic2 already 2647 * added it to the object names. 2648 */ 2649 if (name != NULL) 2650 object_add_name(obj, name); 2651 obj->path = path; 2652 if (!digest_dynamic(obj, 0)) 2653 goto errp; 2654 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", obj->path, 2655 obj->valid_hash_sysv, obj->valid_hash_gnu, obj->dynsymcount); 2656 if (obj->z_pie && (flags & RTLD_LO_TRACE) == 0) { 2657 dbg("refusing to load PIE executable \"%s\"", obj->path); 2658 _rtld_error("Cannot load PIE binary %s as DSO", obj->path); 2659 goto errp; 2660 } 2661 if (obj->z_noopen && (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) == 2662 RTLD_LO_DLOPEN) { 2663 dbg("refusing to load non-loadable \"%s\"", obj->path); 2664 _rtld_error("Cannot dlopen non-loadable %s", obj->path); 2665 goto errp; 2666 } 2667 2668 obj->dlopened = (flags & RTLD_LO_DLOPEN) != 0; 2669 TAILQ_INSERT_TAIL(&obj_list, obj, next); 2670 obj_count++; 2671 obj_loads++; 2672 linkmap_add(obj); /* for GDB & dlinfo() */ 2673 max_stack_flags |= obj->stack_flags; 2674 2675 dbg(" %p .. %p: %s", obj->mapbase, 2676 obj->mapbase + obj->mapsize - 1, obj->path); 2677 if (obj->textrel) 2678 dbg(" WARNING: %s has impure text", obj->path); 2679 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 2680 obj->path); 2681 2682 return (obj); 2683 2684 errp: 2685 munmap(obj->mapbase, obj->mapsize); 2686 obj_free(obj); 2687 return (NULL); 2688 } 2689 2690 static Obj_Entry * 2691 obj_from_addr(const void *addr) 2692 { 2693 Obj_Entry *obj; 2694 2695 TAILQ_FOREACH(obj, &obj_list, next) { 2696 if (obj->marker) 2697 continue; 2698 if (addr < (void *) obj->mapbase) 2699 continue; 2700 if (addr < (void *)(obj->mapbase + obj->mapsize)) 2701 return obj; 2702 } 2703 return NULL; 2704 } 2705 2706 static void 2707 preinit_main(void) 2708 { 2709 Elf_Addr *preinit_addr; 2710 int index; 2711 2712 preinit_addr = (Elf_Addr *)obj_main->preinit_array; 2713 if (preinit_addr == NULL) 2714 return; 2715 2716 for (index = 0; index < obj_main->preinit_array_num; index++) { 2717 if (preinit_addr[index] != 0 && preinit_addr[index] != 1) { 2718 dbg("calling preinit function for %s at %p", obj_main->path, 2719 (void *)preinit_addr[index]); 2720 LD_UTRACE(UTRACE_INIT_CALL, obj_main, (void *)preinit_addr[index], 2721 0, 0, obj_main->path); 2722 call_init_pointer(obj_main, preinit_addr[index]); 2723 } 2724 } 2725 } 2726 2727 /* 2728 * Call the finalization functions for each of the objects in "list" 2729 * belonging to the DAG of "root" and referenced once. If NULL "root" 2730 * is specified, every finalization function will be called regardless 2731 * of the reference count and the list elements won't be freed. All of 2732 * the objects are expected to have non-NULL fini functions. 2733 */ 2734 static void 2735 objlist_call_fini(Objlist *list, Obj_Entry *root, RtldLockState *lockstate) 2736 { 2737 Objlist_Entry *elm; 2738 char *saved_msg; 2739 Elf_Addr *fini_addr; 2740 int index; 2741 2742 assert(root == NULL || root->refcount == 1); 2743 2744 if (root != NULL) 2745 root->doomed = true; 2746 2747 /* 2748 * Preserve the current error message since a fini function might 2749 * call into the dynamic linker and overwrite it. 2750 */ 2751 saved_msg = errmsg_save(); 2752 do { 2753 STAILQ_FOREACH(elm, list, link) { 2754 if (root != NULL && (elm->obj->refcount != 1 || 2755 objlist_find(&root->dagmembers, elm->obj) == NULL)) 2756 continue; 2757 /* Remove object from fini list to prevent recursive invocation. */ 2758 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 2759 /* Ensure that new references cannot be acquired. */ 2760 elm->obj->doomed = true; 2761 2762 hold_object(elm->obj); 2763 lock_release(rtld_bind_lock, lockstate); 2764 /* 2765 * It is legal to have both DT_FINI and DT_FINI_ARRAY defined. 2766 * When this happens, DT_FINI_ARRAY is processed first. 2767 */ 2768 fini_addr = (Elf_Addr *)elm->obj->fini_array; 2769 if (fini_addr != NULL && elm->obj->fini_array_num > 0) { 2770 for (index = elm->obj->fini_array_num - 1; index >= 0; 2771 index--) { 2772 if (fini_addr[index] != 0 && fini_addr[index] != 1) { 2773 dbg("calling fini function for %s at %p", 2774 elm->obj->path, (void *)fini_addr[index]); 2775 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, 2776 (void *)fini_addr[index], 0, 0, elm->obj->path); 2777 call_initfini_pointer(elm->obj, fini_addr[index]); 2778 } 2779 } 2780 } 2781 if (elm->obj->fini != (Elf_Addr)NULL) { 2782 dbg("calling fini function for %s at %p", elm->obj->path, 2783 (void *)elm->obj->fini); 2784 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, (void *)elm->obj->fini, 2785 0, 0, elm->obj->path); 2786 call_initfini_pointer(elm->obj, elm->obj->fini); 2787 } 2788 wlock_acquire(rtld_bind_lock, lockstate); 2789 unhold_object(elm->obj); 2790 /* No need to free anything if process is going down. */ 2791 if (root != NULL) 2792 free(elm); 2793 /* 2794 * We must restart the list traversal after every fini call 2795 * because a dlclose() call from the fini function or from 2796 * another thread might have modified the reference counts. 2797 */ 2798 break; 2799 } 2800 } while (elm != NULL); 2801 errmsg_restore(saved_msg); 2802 } 2803 2804 /* 2805 * Call the initialization functions for each of the objects in 2806 * "list". All of the objects are expected to have non-NULL init 2807 * functions. 2808 */ 2809 static void 2810 objlist_call_init(Objlist *list, RtldLockState *lockstate) 2811 { 2812 Objlist_Entry *elm; 2813 Obj_Entry *obj; 2814 char *saved_msg; 2815 Elf_Addr *init_addr; 2816 void (*reg)(void (*)(void)); 2817 int index; 2818 2819 /* 2820 * Clean init_scanned flag so that objects can be rechecked and 2821 * possibly initialized earlier if any of vectors called below 2822 * cause the change by using dlopen. 2823 */ 2824 TAILQ_FOREACH(obj, &obj_list, next) { 2825 if (obj->marker) 2826 continue; 2827 obj->init_scanned = false; 2828 } 2829 2830 /* 2831 * Preserve the current error message since an init function might 2832 * call into the dynamic linker and overwrite it. 2833 */ 2834 saved_msg = errmsg_save(); 2835 STAILQ_FOREACH(elm, list, link) { 2836 if (elm->obj->init_done) /* Initialized early. */ 2837 continue; 2838 /* 2839 * Race: other thread might try to use this object before current 2840 * one completes the initialization. Not much can be done here 2841 * without better locking. 2842 */ 2843 elm->obj->init_done = true; 2844 hold_object(elm->obj); 2845 reg = NULL; 2846 if (elm->obj == obj_main && obj_main->crt_no_init) { 2847 reg = (void (*)(void (*)(void)))get_program_var_addr( 2848 "__libc_atexit", lockstate); 2849 } 2850 lock_release(rtld_bind_lock, lockstate); 2851 if (reg != NULL) { 2852 reg(rtld_exit); 2853 rtld_exit_ptr = rtld_nop_exit; 2854 } 2855 2856 /* 2857 * It is legal to have both DT_INIT and DT_INIT_ARRAY defined. 2858 * When this happens, DT_INIT is processed first. 2859 */ 2860 if (elm->obj->init != (Elf_Addr)NULL) { 2861 dbg("calling init function for %s at %p", elm->obj->path, 2862 (void *)elm->obj->init); 2863 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, (void *)elm->obj->init, 2864 0, 0, elm->obj->path); 2865 call_init_pointer(elm->obj, elm->obj->init); 2866 } 2867 init_addr = (Elf_Addr *)elm->obj->init_array; 2868 if (init_addr != NULL) { 2869 for (index = 0; index < elm->obj->init_array_num; index++) { 2870 if (init_addr[index] != 0 && init_addr[index] != 1) { 2871 dbg("calling init function for %s at %p", elm->obj->path, 2872 (void *)init_addr[index]); 2873 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, 2874 (void *)init_addr[index], 0, 0, elm->obj->path); 2875 call_init_pointer(elm->obj, init_addr[index]); 2876 } 2877 } 2878 } 2879 wlock_acquire(rtld_bind_lock, lockstate); 2880 unhold_object(elm->obj); 2881 } 2882 errmsg_restore(saved_msg); 2883 } 2884 2885 static void 2886 objlist_clear(Objlist *list) 2887 { 2888 Objlist_Entry *elm; 2889 2890 while (!STAILQ_EMPTY(list)) { 2891 elm = STAILQ_FIRST(list); 2892 STAILQ_REMOVE_HEAD(list, link); 2893 free(elm); 2894 } 2895 } 2896 2897 static Objlist_Entry * 2898 objlist_find(Objlist *list, const Obj_Entry *obj) 2899 { 2900 Objlist_Entry *elm; 2901 2902 STAILQ_FOREACH(elm, list, link) 2903 if (elm->obj == obj) 2904 return elm; 2905 return NULL; 2906 } 2907 2908 static void 2909 objlist_init(Objlist *list) 2910 { 2911 STAILQ_INIT(list); 2912 } 2913 2914 static void 2915 objlist_push_head(Objlist *list, Obj_Entry *obj) 2916 { 2917 Objlist_Entry *elm; 2918 2919 elm = NEW(Objlist_Entry); 2920 elm->obj = obj; 2921 STAILQ_INSERT_HEAD(list, elm, link); 2922 } 2923 2924 static void 2925 objlist_push_tail(Objlist *list, Obj_Entry *obj) 2926 { 2927 Objlist_Entry *elm; 2928 2929 elm = NEW(Objlist_Entry); 2930 elm->obj = obj; 2931 STAILQ_INSERT_TAIL(list, elm, link); 2932 } 2933 2934 static void 2935 objlist_put_after(Objlist *list, Obj_Entry *listobj, Obj_Entry *obj) 2936 { 2937 Objlist_Entry *elm, *listelm; 2938 2939 STAILQ_FOREACH(listelm, list, link) { 2940 if (listelm->obj == listobj) 2941 break; 2942 } 2943 elm = NEW(Objlist_Entry); 2944 elm->obj = obj; 2945 if (listelm != NULL) 2946 STAILQ_INSERT_AFTER(list, listelm, elm, link); 2947 else 2948 STAILQ_INSERT_TAIL(list, elm, link); 2949 } 2950 2951 static void 2952 objlist_remove(Objlist *list, Obj_Entry *obj) 2953 { 2954 Objlist_Entry *elm; 2955 2956 if ((elm = objlist_find(list, obj)) != NULL) { 2957 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 2958 free(elm); 2959 } 2960 } 2961 2962 /* 2963 * Relocate dag rooted in the specified object. 2964 * Returns 0 on success, or -1 on failure. 2965 */ 2966 2967 static int 2968 relocate_object_dag(Obj_Entry *root, bool bind_now, Obj_Entry *rtldobj, 2969 int flags, RtldLockState *lockstate) 2970 { 2971 Objlist_Entry *elm; 2972 int error; 2973 2974 error = 0; 2975 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2976 error = relocate_object(elm->obj, bind_now, rtldobj, flags, 2977 lockstate); 2978 if (error == -1) 2979 break; 2980 } 2981 return (error); 2982 } 2983 2984 /* 2985 * Prepare for, or clean after, relocating an object marked with 2986 * DT_TEXTREL or DF_TEXTREL. Before relocating, all read-only 2987 * segments are remapped read-write. After relocations are done, the 2988 * segment's permissions are returned back to the modes specified in 2989 * the phdrs. If any relocation happened, or always for wired 2990 * program, COW is triggered. 2991 */ 2992 static int 2993 reloc_textrel_prot(Obj_Entry *obj, bool before) 2994 { 2995 const Elf_Phdr *ph; 2996 void *base; 2997 size_t l, sz; 2998 int prot; 2999 3000 for (l = obj->phsize / sizeof(*ph), ph = obj->phdr; l > 0; 3001 l--, ph++) { 3002 if (ph->p_type != PT_LOAD || (ph->p_flags & PF_W) != 0) 3003 continue; 3004 base = obj->relocbase + trunc_page(ph->p_vaddr); 3005 sz = round_page(ph->p_vaddr + ph->p_filesz) - 3006 trunc_page(ph->p_vaddr); 3007 prot = before ? (PROT_READ | PROT_WRITE) : 3008 convert_prot(ph->p_flags); 3009 if (mprotect(base, sz, prot) == -1) { 3010 _rtld_error("%s: Cannot write-%sable text segment: %s", 3011 obj->path, before ? "en" : "dis", 3012 rtld_strerror(errno)); 3013 return (-1); 3014 } 3015 } 3016 return (0); 3017 } 3018 3019 /* 3020 * Relocate single object. 3021 * Returns 0 on success, or -1 on failure. 3022 */ 3023 static int 3024 relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, 3025 int flags, RtldLockState *lockstate) 3026 { 3027 3028 if (obj->relocated) 3029 return (0); 3030 obj->relocated = true; 3031 if (obj != rtldobj) 3032 dbg("relocating \"%s\"", obj->path); 3033 3034 if (obj->symtab == NULL || obj->strtab == NULL || 3035 !(obj->valid_hash_sysv || obj->valid_hash_gnu)) 3036 dbg("object %s has no run-time symbol table", obj->path); 3037 3038 /* There are relocations to the write-protected text segment. */ 3039 if (obj->textrel && reloc_textrel_prot(obj, true) != 0) 3040 return (-1); 3041 3042 /* Process the non-PLT non-IFUNC relocations. */ 3043 if (reloc_non_plt(obj, rtldobj, flags, lockstate)) 3044 return (-1); 3045 3046 /* Re-protected the text segment. */ 3047 if (obj->textrel && reloc_textrel_prot(obj, false) != 0) 3048 return (-1); 3049 3050 /* Set the special PLT or GOT entries. */ 3051 init_pltgot(obj); 3052 3053 /* Process the PLT relocations. */ 3054 if (reloc_plt(obj, flags, lockstate) == -1) 3055 return (-1); 3056 /* Relocate the jump slots if we are doing immediate binding. */ 3057 if ((obj->bind_now || bind_now) && reloc_jmpslots(obj, flags, 3058 lockstate) == -1) 3059 return (-1); 3060 3061 if (!obj->mainprog && obj_enforce_relro(obj) == -1) 3062 return (-1); 3063 3064 /* 3065 * Set up the magic number and version in the Obj_Entry. These 3066 * were checked in the crt1.o from the original ElfKit, so we 3067 * set them for backward compatibility. 3068 */ 3069 obj->magic = RTLD_MAGIC; 3070 obj->version = RTLD_VERSION; 3071 3072 return (0); 3073 } 3074 3075 /* 3076 * Relocate newly-loaded shared objects. The argument is a pointer to 3077 * the Obj_Entry for the first such object. All objects from the first 3078 * to the end of the list of objects are relocated. Returns 0 on success, 3079 * or -1 on failure. 3080 */ 3081 static int 3082 relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj, 3083 int flags, RtldLockState *lockstate) 3084 { 3085 Obj_Entry *obj; 3086 int error; 3087 3088 for (error = 0, obj = first; obj != NULL; 3089 obj = TAILQ_NEXT(obj, next)) { 3090 if (obj->marker) 3091 continue; 3092 error = relocate_object(obj, bind_now, rtldobj, flags, 3093 lockstate); 3094 if (error == -1) 3095 break; 3096 } 3097 return (error); 3098 } 3099 3100 /* 3101 * The handling of R_MACHINE_IRELATIVE relocations and jumpslots 3102 * referencing STT_GNU_IFUNC symbols is postponed till the other 3103 * relocations are done. The indirect functions specified as 3104 * ifunc are allowed to call other symbols, so we need to have 3105 * objects relocated before asking for resolution from indirects. 3106 * 3107 * The R_MACHINE_IRELATIVE slots are resolved in greedy fashion, 3108 * instead of the usual lazy handling of PLT slots. It is 3109 * consistent with how GNU does it. 3110 */ 3111 static int 3112 resolve_object_ifunc(Obj_Entry *obj, bool bind_now, int flags, 3113 RtldLockState *lockstate) 3114 { 3115 3116 if (obj->ifuncs_resolved) 3117 return (0); 3118 obj->ifuncs_resolved = true; 3119 if (!obj->irelative && !obj->irelative_nonplt && 3120 !((obj->bind_now || bind_now) && obj->gnu_ifunc) && 3121 !obj->non_plt_gnu_ifunc) 3122 return (0); 3123 if (obj_disable_relro(obj) == -1 || 3124 (obj->irelative && reloc_iresolve(obj, lockstate) == -1) || 3125 (obj->irelative_nonplt && reloc_iresolve_nonplt(obj, 3126 lockstate) == -1) || 3127 ((obj->bind_now || bind_now) && obj->gnu_ifunc && 3128 reloc_gnu_ifunc(obj, flags, lockstate) == -1) || 3129 (obj->non_plt_gnu_ifunc && reloc_non_plt(obj, &obj_rtld, 3130 flags | SYMLOOK_IFUNC, lockstate) == -1) || 3131 obj_enforce_relro(obj) == -1) 3132 return (-1); 3133 return (0); 3134 } 3135 3136 static int 3137 initlist_objects_ifunc(Objlist *list, bool bind_now, int flags, 3138 RtldLockState *lockstate) 3139 { 3140 Objlist_Entry *elm; 3141 Obj_Entry *obj; 3142 3143 STAILQ_FOREACH(elm, list, link) { 3144 obj = elm->obj; 3145 if (obj->marker) 3146 continue; 3147 if (resolve_object_ifunc(obj, bind_now, flags, 3148 lockstate) == -1) 3149 return (-1); 3150 } 3151 return (0); 3152 } 3153 3154 /* 3155 * Cleanup procedure. It will be called (by the atexit mechanism) just 3156 * before the process exits. 3157 */ 3158 static void 3159 rtld_exit(void) 3160 { 3161 RtldLockState lockstate; 3162 3163 wlock_acquire(rtld_bind_lock, &lockstate); 3164 dbg("rtld_exit()"); 3165 objlist_call_fini(&list_fini, NULL, &lockstate); 3166 /* No need to remove the items from the list, since we are exiting. */ 3167 if (!libmap_disable) 3168 lm_fini(); 3169 lock_release(rtld_bind_lock, &lockstate); 3170 } 3171 3172 static void 3173 rtld_nop_exit(void) 3174 { 3175 } 3176 3177 /* 3178 * Iterate over a search path, translate each element, and invoke the 3179 * callback on the result. 3180 */ 3181 static void * 3182 path_enumerate(const char *path, path_enum_proc callback, 3183 const char *refobj_path, void *arg) 3184 { 3185 const char *trans; 3186 if (path == NULL) 3187 return (NULL); 3188 3189 path += strspn(path, ":;"); 3190 while (*path != '\0') { 3191 size_t len; 3192 char *res; 3193 3194 len = strcspn(path, ":;"); 3195 trans = lm_findn(refobj_path, path, len); 3196 if (trans) 3197 res = callback(trans, strlen(trans), arg); 3198 else 3199 res = callback(path, len, arg); 3200 3201 if (res != NULL) 3202 return (res); 3203 3204 path += len; 3205 path += strspn(path, ":;"); 3206 } 3207 3208 return (NULL); 3209 } 3210 3211 struct try_library_args { 3212 const char *name; 3213 size_t namelen; 3214 char *buffer; 3215 size_t buflen; 3216 int fd; 3217 }; 3218 3219 static void * 3220 try_library_path(const char *dir, size_t dirlen, void *param) 3221 { 3222 struct try_library_args *arg; 3223 int fd; 3224 3225 arg = param; 3226 if (*dir == '/' || trust) { 3227 char *pathname; 3228 3229 if (dirlen + 1 + arg->namelen + 1 > arg->buflen) 3230 return (NULL); 3231 3232 pathname = arg->buffer; 3233 strncpy(pathname, dir, dirlen); 3234 pathname[dirlen] = '/'; 3235 strcpy(pathname + dirlen + 1, arg->name); 3236 3237 dbg(" Trying \"%s\"", pathname); 3238 fd = open(pathname, O_RDONLY | O_CLOEXEC | O_VERIFY); 3239 if (fd >= 0) { 3240 dbg(" Opened \"%s\", fd %d", pathname, fd); 3241 pathname = xmalloc(dirlen + 1 + arg->namelen + 1); 3242 strcpy(pathname, arg->buffer); 3243 arg->fd = fd; 3244 return (pathname); 3245 } else { 3246 dbg(" Failed to open \"%s\": %s", 3247 pathname, rtld_strerror(errno)); 3248 } 3249 } 3250 return (NULL); 3251 } 3252 3253 static char * 3254 search_library_path(const char *name, const char *path, 3255 const char *refobj_path, int *fdp) 3256 { 3257 char *p; 3258 struct try_library_args arg; 3259 3260 if (path == NULL) 3261 return NULL; 3262 3263 arg.name = name; 3264 arg.namelen = strlen(name); 3265 arg.buffer = xmalloc(PATH_MAX); 3266 arg.buflen = PATH_MAX; 3267 arg.fd = -1; 3268 3269 p = path_enumerate(path, try_library_path, refobj_path, &arg); 3270 *fdp = arg.fd; 3271 3272 free(arg.buffer); 3273 3274 return (p); 3275 } 3276 3277 3278 /* 3279 * Finds the library with the given name using the directory descriptors 3280 * listed in the LD_LIBRARY_PATH_FDS environment variable. 3281 * 3282 * Returns a freshly-opened close-on-exec file descriptor for the library, 3283 * or -1 if the library cannot be found. 3284 */ 3285 static char * 3286 search_library_pathfds(const char *name, const char *path, int *fdp) 3287 { 3288 char *envcopy, *fdstr, *found, *last_token; 3289 size_t len; 3290 int dirfd, fd; 3291 3292 dbg("%s('%s', '%s', fdp)", __func__, name, path); 3293 3294 /* Don't load from user-specified libdirs into setuid binaries. */ 3295 if (!trust) 3296 return (NULL); 3297 3298 /* We can't do anything if LD_LIBRARY_PATH_FDS isn't set. */ 3299 if (path == NULL) 3300 return (NULL); 3301 3302 /* LD_LIBRARY_PATH_FDS only works with relative paths. */ 3303 if (name[0] == '/') { 3304 dbg("Absolute path (%s) passed to %s", name, __func__); 3305 return (NULL); 3306 } 3307 3308 /* 3309 * Use strtok_r() to walk the FD:FD:FD list. This requires a local 3310 * copy of the path, as strtok_r rewrites separator tokens 3311 * with '\0'. 3312 */ 3313 found = NULL; 3314 envcopy = xstrdup(path); 3315 for (fdstr = strtok_r(envcopy, ":", &last_token); fdstr != NULL; 3316 fdstr = strtok_r(NULL, ":", &last_token)) { 3317 dirfd = parse_integer(fdstr); 3318 if (dirfd < 0) { 3319 _rtld_error("failed to parse directory FD: '%s'", 3320 fdstr); 3321 break; 3322 } 3323 fd = __sys_openat(dirfd, name, O_RDONLY | O_CLOEXEC | O_VERIFY); 3324 if (fd >= 0) { 3325 *fdp = fd; 3326 len = strlen(fdstr) + strlen(name) + 3; 3327 found = xmalloc(len); 3328 if (rtld_snprintf(found, len, "#%d/%s", dirfd, name) < 0) { 3329 _rtld_error("error generating '%d/%s'", 3330 dirfd, name); 3331 rtld_die(); 3332 } 3333 dbg("open('%s') => %d", found, fd); 3334 break; 3335 } 3336 } 3337 free(envcopy); 3338 3339 return (found); 3340 } 3341 3342 3343 int 3344 dlclose(void *handle) 3345 { 3346 RtldLockState lockstate; 3347 int error; 3348 3349 wlock_acquire(rtld_bind_lock, &lockstate); 3350 error = dlclose_locked(handle, &lockstate); 3351 lock_release(rtld_bind_lock, &lockstate); 3352 return (error); 3353 } 3354 3355 static int 3356 dlclose_locked(void *handle, RtldLockState *lockstate) 3357 { 3358 Obj_Entry *root; 3359 3360 root = dlcheck(handle); 3361 if (root == NULL) 3362 return -1; 3363 LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount, 3364 root->path); 3365 3366 /* Unreference the object and its dependencies. */ 3367 root->dl_refcount--; 3368 3369 if (root->refcount == 1) { 3370 /* 3371 * The object will be no longer referenced, so we must unload it. 3372 * First, call the fini functions. 3373 */ 3374 objlist_call_fini(&list_fini, root, lockstate); 3375 3376 unref_dag(root); 3377 3378 /* Finish cleaning up the newly-unreferenced objects. */ 3379 GDB_STATE(RT_DELETE,&root->linkmap); 3380 unload_object(root, lockstate); 3381 GDB_STATE(RT_CONSISTENT,NULL); 3382 } else 3383 unref_dag(root); 3384 3385 LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL); 3386 return 0; 3387 } 3388 3389 char * 3390 dlerror(void) 3391 { 3392 char *msg = error_message; 3393 error_message = NULL; 3394 return msg; 3395 } 3396 3397 /* 3398 * This function is deprecated and has no effect. 3399 */ 3400 void 3401 dllockinit(void *context, 3402 void *(*_lock_create)(void *context) __unused, 3403 void (*_rlock_acquire)(void *lock) __unused, 3404 void (*_wlock_acquire)(void *lock) __unused, 3405 void (*_lock_release)(void *lock) __unused, 3406 void (*_lock_destroy)(void *lock) __unused, 3407 void (*context_destroy)(void *context)) 3408 { 3409 static void *cur_context; 3410 static void (*cur_context_destroy)(void *); 3411 3412 /* Just destroy the context from the previous call, if necessary. */ 3413 if (cur_context_destroy != NULL) 3414 cur_context_destroy(cur_context); 3415 cur_context = context; 3416 cur_context_destroy = context_destroy; 3417 } 3418 3419 void * 3420 dlopen(const char *name, int mode) 3421 { 3422 3423 return (rtld_dlopen(name, -1, mode)); 3424 } 3425 3426 void * 3427 fdlopen(int fd, int mode) 3428 { 3429 3430 return (rtld_dlopen(NULL, fd, mode)); 3431 } 3432 3433 static void * 3434 rtld_dlopen(const char *name, int fd, int mode) 3435 { 3436 RtldLockState lockstate; 3437 int lo_flags; 3438 3439 LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name); 3440 ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1"; 3441 if (ld_tracing != NULL) { 3442 rlock_acquire(rtld_bind_lock, &lockstate); 3443 if (sigsetjmp(lockstate.env, 0) != 0) 3444 lock_upgrade(rtld_bind_lock, &lockstate); 3445 environ = __DECONST(char **, *get_program_var_addr("environ", &lockstate)); 3446 lock_release(rtld_bind_lock, &lockstate); 3447 } 3448 lo_flags = RTLD_LO_DLOPEN; 3449 if (mode & RTLD_NODELETE) 3450 lo_flags |= RTLD_LO_NODELETE; 3451 if (mode & RTLD_NOLOAD) 3452 lo_flags |= RTLD_LO_NOLOAD; 3453 if (mode & RTLD_DEEPBIND) 3454 lo_flags |= RTLD_LO_DEEPBIND; 3455 if (ld_tracing != NULL) 3456 lo_flags |= RTLD_LO_TRACE | RTLD_LO_IGNSTLS; 3457 3458 return (dlopen_object(name, fd, obj_main, lo_flags, 3459 mode & (RTLD_MODEMASK | RTLD_GLOBAL), NULL)); 3460 } 3461 3462 static void 3463 dlopen_cleanup(Obj_Entry *obj, RtldLockState *lockstate) 3464 { 3465 3466 obj->dl_refcount--; 3467 unref_dag(obj); 3468 if (obj->refcount == 0) 3469 unload_object(obj, lockstate); 3470 } 3471 3472 static Obj_Entry * 3473 dlopen_object(const char *name, int fd, Obj_Entry *refobj, int lo_flags, 3474 int mode, RtldLockState *lockstate) 3475 { 3476 Obj_Entry *old_obj_tail; 3477 Obj_Entry *obj; 3478 Objlist initlist; 3479 RtldLockState mlockstate; 3480 int result; 3481 3482 dbg("dlopen_object name \"%s\" fd %d refobj \"%s\" lo_flags %#x mode %#x", 3483 name != NULL ? name : "<null>", fd, refobj == NULL ? "<null>" : 3484 refobj->path, lo_flags, mode); 3485 objlist_init(&initlist); 3486 3487 if (lockstate == NULL && !(lo_flags & RTLD_LO_EARLY)) { 3488 wlock_acquire(rtld_bind_lock, &mlockstate); 3489 lockstate = &mlockstate; 3490 } 3491 GDB_STATE(RT_ADD,NULL); 3492 3493 old_obj_tail = globallist_curr(TAILQ_LAST(&obj_list, obj_entry_q)); 3494 obj = NULL; 3495 if (name == NULL && fd == -1) { 3496 obj = obj_main; 3497 obj->refcount++; 3498 } else { 3499 obj = load_object(name, fd, refobj, lo_flags); 3500 } 3501 3502 if (obj) { 3503 obj->dl_refcount++; 3504 if (mode & RTLD_GLOBAL && objlist_find(&list_global, obj) == NULL) 3505 objlist_push_tail(&list_global, obj); 3506 if (globallist_next(old_obj_tail) != NULL) { 3507 /* We loaded something new. */ 3508 assert(globallist_next(old_obj_tail) == obj); 3509 if ((lo_flags & RTLD_LO_DEEPBIND) != 0) 3510 obj->symbolic = true; 3511 result = 0; 3512 if ((lo_flags & (RTLD_LO_EARLY | RTLD_LO_IGNSTLS)) == 0 && 3513 obj->static_tls && !allocate_tls_offset(obj)) { 3514 _rtld_error("%s: No space available " 3515 "for static Thread Local Storage", obj->path); 3516 result = -1; 3517 } 3518 if (result != -1) 3519 result = load_needed_objects(obj, lo_flags & (RTLD_LO_DLOPEN | 3520 RTLD_LO_EARLY | RTLD_LO_IGNSTLS | RTLD_LO_TRACE)); 3521 init_dag(obj); 3522 ref_dag(obj); 3523 if (result != -1) 3524 result = rtld_verify_versions(&obj->dagmembers); 3525 if (result != -1 && ld_tracing) 3526 goto trace; 3527 if (result == -1 || relocate_object_dag(obj, 3528 (mode & RTLD_MODEMASK) == RTLD_NOW, &obj_rtld, 3529 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 3530 lockstate) == -1) { 3531 dlopen_cleanup(obj, lockstate); 3532 obj = NULL; 3533 } else if (lo_flags & RTLD_LO_EARLY) { 3534 /* 3535 * Do not call the init functions for early loaded 3536 * filtees. The image is still not initialized enough 3537 * for them to work. 3538 * 3539 * Our object is found by the global object list and 3540 * will be ordered among all init calls done right 3541 * before transferring control to main. 3542 */ 3543 } else { 3544 /* Make list of init functions to call. */ 3545 initlist_add_objects(obj, obj, &initlist); 3546 } 3547 /* 3548 * Process all no_delete or global objects here, given 3549 * them own DAGs to prevent their dependencies from being 3550 * unloaded. This has to be done after we have loaded all 3551 * of the dependencies, so that we do not miss any. 3552 */ 3553 if (obj != NULL) 3554 process_z(obj); 3555 } else { 3556 /* 3557 * Bump the reference counts for objects on this DAG. If 3558 * this is the first dlopen() call for the object that was 3559 * already loaded as a dependency, initialize the dag 3560 * starting at it. 3561 */ 3562 init_dag(obj); 3563 ref_dag(obj); 3564 3565 if ((lo_flags & RTLD_LO_TRACE) != 0) 3566 goto trace; 3567 } 3568 if (obj != NULL && ((lo_flags & RTLD_LO_NODELETE) != 0 || 3569 obj->z_nodelete) && !obj->ref_nodel) { 3570 dbg("obj %s nodelete", obj->path); 3571 ref_dag(obj); 3572 obj->z_nodelete = obj->ref_nodel = true; 3573 } 3574 } 3575 3576 LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0, 3577 name); 3578 GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL); 3579 3580 if ((lo_flags & RTLD_LO_EARLY) == 0) { 3581 map_stacks_exec(lockstate); 3582 if (obj != NULL) 3583 distribute_static_tls(&initlist, lockstate); 3584 } 3585 3586 if (initlist_objects_ifunc(&initlist, (mode & RTLD_MODEMASK) == RTLD_NOW, 3587 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 3588 lockstate) == -1) { 3589 objlist_clear(&initlist); 3590 dlopen_cleanup(obj, lockstate); 3591 if (lockstate == &mlockstate) 3592 lock_release(rtld_bind_lock, lockstate); 3593 return (NULL); 3594 } 3595 3596 if (!(lo_flags & RTLD_LO_EARLY)) { 3597 /* Call the init functions. */ 3598 objlist_call_init(&initlist, lockstate); 3599 } 3600 objlist_clear(&initlist); 3601 if (lockstate == &mlockstate) 3602 lock_release(rtld_bind_lock, lockstate); 3603 return obj; 3604 trace: 3605 trace_loaded_objects(obj); 3606 if (lockstate == &mlockstate) 3607 lock_release(rtld_bind_lock, lockstate); 3608 exit(0); 3609 } 3610 3611 static void * 3612 do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve, 3613 int flags) 3614 { 3615 DoneList donelist; 3616 const Obj_Entry *obj, *defobj; 3617 const Elf_Sym *def; 3618 SymLook req; 3619 RtldLockState lockstate; 3620 tls_index ti; 3621 void *sym; 3622 int res; 3623 3624 def = NULL; 3625 defobj = NULL; 3626 symlook_init(&req, name); 3627 req.ventry = ve; 3628 req.flags = flags | SYMLOOK_IN_PLT; 3629 req.lockstate = &lockstate; 3630 3631 LD_UTRACE(UTRACE_DLSYM_START, handle, NULL, 0, 0, name); 3632 rlock_acquire(rtld_bind_lock, &lockstate); 3633 if (sigsetjmp(lockstate.env, 0) != 0) 3634 lock_upgrade(rtld_bind_lock, &lockstate); 3635 if (handle == NULL || handle == RTLD_NEXT || 3636 handle == RTLD_DEFAULT || handle == RTLD_SELF) { 3637 3638 if ((obj = obj_from_addr(retaddr)) == NULL) { 3639 _rtld_error("Cannot determine caller's shared object"); 3640 lock_release(rtld_bind_lock, &lockstate); 3641 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 3642 return NULL; 3643 } 3644 if (handle == NULL) { /* Just the caller's shared object. */ 3645 res = symlook_obj(&req, obj); 3646 if (res == 0) { 3647 def = req.sym_out; 3648 defobj = req.defobj_out; 3649 } 3650 } else if (handle == RTLD_NEXT || /* Objects after caller's */ 3651 handle == RTLD_SELF) { /* ... caller included */ 3652 if (handle == RTLD_NEXT) 3653 obj = globallist_next(obj); 3654 for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 3655 if (obj->marker) 3656 continue; 3657 res = symlook_obj(&req, obj); 3658 if (res == 0) { 3659 if (def == NULL || 3660 ELF_ST_BIND(req.sym_out->st_info) != STB_WEAK) { 3661 def = req.sym_out; 3662 defobj = req.defobj_out; 3663 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 3664 break; 3665 } 3666 } 3667 } 3668 /* 3669 * Search the dynamic linker itself, and possibly resolve the 3670 * symbol from there. This is how the application links to 3671 * dynamic linker services such as dlopen. 3672 */ 3673 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 3674 res = symlook_obj(&req, &obj_rtld); 3675 if (res == 0) { 3676 def = req.sym_out; 3677 defobj = req.defobj_out; 3678 } 3679 } 3680 } else { 3681 assert(handle == RTLD_DEFAULT); 3682 res = symlook_default(&req, obj); 3683 if (res == 0) { 3684 defobj = req.defobj_out; 3685 def = req.sym_out; 3686 } 3687 } 3688 } else { 3689 if ((obj = dlcheck(handle)) == NULL) { 3690 lock_release(rtld_bind_lock, &lockstate); 3691 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 3692 return NULL; 3693 } 3694 3695 donelist_init(&donelist); 3696 if (obj->mainprog) { 3697 /* Handle obtained by dlopen(NULL, ...) implies global scope. */ 3698 res = symlook_global(&req, &donelist); 3699 if (res == 0) { 3700 def = req.sym_out; 3701 defobj = req.defobj_out; 3702 } 3703 /* 3704 * Search the dynamic linker itself, and possibly resolve the 3705 * symbol from there. This is how the application links to 3706 * dynamic linker services such as dlopen. 3707 */ 3708 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 3709 res = symlook_obj(&req, &obj_rtld); 3710 if (res == 0) { 3711 def = req.sym_out; 3712 defobj = req.defobj_out; 3713 } 3714 } 3715 } 3716 else { 3717 /* Search the whole DAG rooted at the given object. */ 3718 res = symlook_list(&req, &obj->dagmembers, &donelist); 3719 if (res == 0) { 3720 def = req.sym_out; 3721 defobj = req.defobj_out; 3722 } 3723 } 3724 } 3725 3726 if (def != NULL) { 3727 lock_release(rtld_bind_lock, &lockstate); 3728 3729 /* 3730 * The value required by the caller is derived from the value 3731 * of the symbol. this is simply the relocated value of the 3732 * symbol. 3733 */ 3734 if (ELF_ST_TYPE(def->st_info) == STT_FUNC) 3735 sym = make_function_pointer(def, defobj); 3736 else if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 3737 sym = rtld_resolve_ifunc(defobj, def); 3738 else if (ELF_ST_TYPE(def->st_info) == STT_TLS) { 3739 ti.ti_module = defobj->tlsindex; 3740 ti.ti_offset = def->st_value; 3741 sym = __tls_get_addr(&ti); 3742 } else 3743 sym = defobj->relocbase + def->st_value; 3744 LD_UTRACE(UTRACE_DLSYM_STOP, handle, sym, 0, 0, name); 3745 return (sym); 3746 } 3747 3748 _rtld_error("Undefined symbol \"%s%s%s\"", name, ve != NULL ? "@" : "", 3749 ve != NULL ? ve->name : ""); 3750 lock_release(rtld_bind_lock, &lockstate); 3751 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 3752 return NULL; 3753 } 3754 3755 void * 3756 dlsym(void *handle, const char *name) 3757 { 3758 return do_dlsym(handle, name, __builtin_return_address(0), NULL, 3759 SYMLOOK_DLSYM); 3760 } 3761 3762 dlfunc_t 3763 dlfunc(void *handle, const char *name) 3764 { 3765 union { 3766 void *d; 3767 dlfunc_t f; 3768 } rv; 3769 3770 rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL, 3771 SYMLOOK_DLSYM); 3772 return (rv.f); 3773 } 3774 3775 void * 3776 dlvsym(void *handle, const char *name, const char *version) 3777 { 3778 Ver_Entry ventry; 3779 3780 ventry.name = version; 3781 ventry.file = NULL; 3782 ventry.hash = elf_hash(version); 3783 ventry.flags= 0; 3784 return do_dlsym(handle, name, __builtin_return_address(0), &ventry, 3785 SYMLOOK_DLSYM); 3786 } 3787 3788 int 3789 _rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info) 3790 { 3791 const Obj_Entry *obj; 3792 RtldLockState lockstate; 3793 3794 rlock_acquire(rtld_bind_lock, &lockstate); 3795 obj = obj_from_addr(addr); 3796 if (obj == NULL) { 3797 _rtld_error("No shared object contains address"); 3798 lock_release(rtld_bind_lock, &lockstate); 3799 return (0); 3800 } 3801 rtld_fill_dl_phdr_info(obj, phdr_info); 3802 lock_release(rtld_bind_lock, &lockstate); 3803 return (1); 3804 } 3805 3806 int 3807 dladdr(const void *addr, Dl_info *info) 3808 { 3809 const Obj_Entry *obj; 3810 const Elf_Sym *def; 3811 void *symbol_addr; 3812 unsigned long symoffset; 3813 RtldLockState lockstate; 3814 3815 rlock_acquire(rtld_bind_lock, &lockstate); 3816 obj = obj_from_addr(addr); 3817 if (obj == NULL) { 3818 _rtld_error("No shared object contains address"); 3819 lock_release(rtld_bind_lock, &lockstate); 3820 return 0; 3821 } 3822 info->dli_fname = obj->path; 3823 info->dli_fbase = obj->mapbase; 3824 info->dli_saddr = (void *)0; 3825 info->dli_sname = NULL; 3826 3827 /* 3828 * Walk the symbol list looking for the symbol whose address is 3829 * closest to the address sent in. 3830 */ 3831 for (symoffset = 0; symoffset < obj->dynsymcount; symoffset++) { 3832 def = obj->symtab + symoffset; 3833 3834 /* 3835 * For skip the symbol if st_shndx is either SHN_UNDEF or 3836 * SHN_COMMON. 3837 */ 3838 if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON) 3839 continue; 3840 3841 /* 3842 * If the symbol is greater than the specified address, or if it 3843 * is further away from addr than the current nearest symbol, 3844 * then reject it. 3845 */ 3846 symbol_addr = obj->relocbase + def->st_value; 3847 if (symbol_addr > addr || symbol_addr < info->dli_saddr) 3848 continue; 3849 3850 /* Update our idea of the nearest symbol. */ 3851 info->dli_sname = obj->strtab + def->st_name; 3852 info->dli_saddr = symbol_addr; 3853 3854 /* Exact match? */ 3855 if (info->dli_saddr == addr) 3856 break; 3857 } 3858 lock_release(rtld_bind_lock, &lockstate); 3859 return 1; 3860 } 3861 3862 int 3863 dlinfo(void *handle, int request, void *p) 3864 { 3865 const Obj_Entry *obj; 3866 RtldLockState lockstate; 3867 int error; 3868 3869 rlock_acquire(rtld_bind_lock, &lockstate); 3870 3871 if (handle == NULL || handle == RTLD_SELF) { 3872 void *retaddr; 3873 3874 retaddr = __builtin_return_address(0); /* __GNUC__ only */ 3875 if ((obj = obj_from_addr(retaddr)) == NULL) 3876 _rtld_error("Cannot determine caller's shared object"); 3877 } else 3878 obj = dlcheck(handle); 3879 3880 if (obj == NULL) { 3881 lock_release(rtld_bind_lock, &lockstate); 3882 return (-1); 3883 } 3884 3885 error = 0; 3886 switch (request) { 3887 case RTLD_DI_LINKMAP: 3888 *((struct link_map const **)p) = &obj->linkmap; 3889 break; 3890 case RTLD_DI_ORIGIN: 3891 error = rtld_dirname(obj->path, p); 3892 break; 3893 3894 case RTLD_DI_SERINFOSIZE: 3895 case RTLD_DI_SERINFO: 3896 error = do_search_info(obj, request, (struct dl_serinfo *)p); 3897 break; 3898 3899 default: 3900 _rtld_error("Invalid request %d passed to dlinfo()", request); 3901 error = -1; 3902 } 3903 3904 lock_release(rtld_bind_lock, &lockstate); 3905 3906 return (error); 3907 } 3908 3909 static void 3910 rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info) 3911 { 3912 3913 phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase; 3914 phdr_info->dlpi_name = obj->path; 3915 phdr_info->dlpi_phdr = obj->phdr; 3916 phdr_info->dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]); 3917 phdr_info->dlpi_tls_modid = obj->tlsindex; 3918 phdr_info->dlpi_tls_data = obj->tlsinit; 3919 phdr_info->dlpi_adds = obj_loads; 3920 phdr_info->dlpi_subs = obj_loads - obj_count; 3921 } 3922 3923 int 3924 dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param) 3925 { 3926 struct dl_phdr_info phdr_info; 3927 Obj_Entry *obj, marker; 3928 RtldLockState bind_lockstate, phdr_lockstate; 3929 int error; 3930 3931 init_marker(&marker); 3932 error = 0; 3933 3934 wlock_acquire(rtld_phdr_lock, &phdr_lockstate); 3935 wlock_acquire(rtld_bind_lock, &bind_lockstate); 3936 for (obj = globallist_curr(TAILQ_FIRST(&obj_list)); obj != NULL;) { 3937 TAILQ_INSERT_AFTER(&obj_list, obj, &marker, next); 3938 rtld_fill_dl_phdr_info(obj, &phdr_info); 3939 hold_object(obj); 3940 lock_release(rtld_bind_lock, &bind_lockstate); 3941 3942 error = callback(&phdr_info, sizeof phdr_info, param); 3943 3944 wlock_acquire(rtld_bind_lock, &bind_lockstate); 3945 unhold_object(obj); 3946 obj = globallist_next(&marker); 3947 TAILQ_REMOVE(&obj_list, &marker, next); 3948 if (error != 0) { 3949 lock_release(rtld_bind_lock, &bind_lockstate); 3950 lock_release(rtld_phdr_lock, &phdr_lockstate); 3951 return (error); 3952 } 3953 } 3954 3955 if (error == 0) { 3956 rtld_fill_dl_phdr_info(&obj_rtld, &phdr_info); 3957 lock_release(rtld_bind_lock, &bind_lockstate); 3958 error = callback(&phdr_info, sizeof(phdr_info), param); 3959 } 3960 lock_release(rtld_phdr_lock, &phdr_lockstate); 3961 return (error); 3962 } 3963 3964 static void * 3965 fill_search_info(const char *dir, size_t dirlen, void *param) 3966 { 3967 struct fill_search_info_args *arg; 3968 3969 arg = param; 3970 3971 if (arg->request == RTLD_DI_SERINFOSIZE) { 3972 arg->serinfo->dls_cnt ++; 3973 arg->serinfo->dls_size += sizeof(struct dl_serpath) + dirlen + 1; 3974 } else { 3975 struct dl_serpath *s_entry; 3976 3977 s_entry = arg->serpath; 3978 s_entry->dls_name = arg->strspace; 3979 s_entry->dls_flags = arg->flags; 3980 3981 strncpy(arg->strspace, dir, dirlen); 3982 arg->strspace[dirlen] = '\0'; 3983 3984 arg->strspace += dirlen + 1; 3985 arg->serpath++; 3986 } 3987 3988 return (NULL); 3989 } 3990 3991 static int 3992 do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info) 3993 { 3994 struct dl_serinfo _info; 3995 struct fill_search_info_args args; 3996 3997 args.request = RTLD_DI_SERINFOSIZE; 3998 args.serinfo = &_info; 3999 4000 _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 4001 _info.dls_cnt = 0; 4002 4003 path_enumerate(obj->rpath, fill_search_info, NULL, &args); 4004 path_enumerate(ld_library_path, fill_search_info, NULL, &args); 4005 path_enumerate(obj->runpath, fill_search_info, NULL, &args); 4006 path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, &args); 4007 if (!obj->z_nodeflib) 4008 path_enumerate(ld_standard_library_path, fill_search_info, NULL, &args); 4009 4010 4011 if (request == RTLD_DI_SERINFOSIZE) { 4012 info->dls_size = _info.dls_size; 4013 info->dls_cnt = _info.dls_cnt; 4014 return (0); 4015 } 4016 4017 if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) { 4018 _rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()"); 4019 return (-1); 4020 } 4021 4022 args.request = RTLD_DI_SERINFO; 4023 args.serinfo = info; 4024 args.serpath = &info->dls_serpath[0]; 4025 args.strspace = (char *)&info->dls_serpath[_info.dls_cnt]; 4026 4027 args.flags = LA_SER_RUNPATH; 4028 if (path_enumerate(obj->rpath, fill_search_info, NULL, &args) != NULL) 4029 return (-1); 4030 4031 args.flags = LA_SER_LIBPATH; 4032 if (path_enumerate(ld_library_path, fill_search_info, NULL, &args) != NULL) 4033 return (-1); 4034 4035 args.flags = LA_SER_RUNPATH; 4036 if (path_enumerate(obj->runpath, fill_search_info, NULL, &args) != NULL) 4037 return (-1); 4038 4039 args.flags = LA_SER_CONFIG; 4040 if (path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, &args) 4041 != NULL) 4042 return (-1); 4043 4044 args.flags = LA_SER_DEFAULT; 4045 if (!obj->z_nodeflib && path_enumerate(ld_standard_library_path, 4046 fill_search_info, NULL, &args) != NULL) 4047 return (-1); 4048 return (0); 4049 } 4050 4051 static int 4052 rtld_dirname(const char *path, char *bname) 4053 { 4054 const char *endp; 4055 4056 /* Empty or NULL string gets treated as "." */ 4057 if (path == NULL || *path == '\0') { 4058 bname[0] = '.'; 4059 bname[1] = '\0'; 4060 return (0); 4061 } 4062 4063 /* Strip trailing slashes */ 4064 endp = path + strlen(path) - 1; 4065 while (endp > path && *endp == '/') 4066 endp--; 4067 4068 /* Find the start of the dir */ 4069 while (endp > path && *endp != '/') 4070 endp--; 4071 4072 /* Either the dir is "/" or there are no slashes */ 4073 if (endp == path) { 4074 bname[0] = *endp == '/' ? '/' : '.'; 4075 bname[1] = '\0'; 4076 return (0); 4077 } else { 4078 do { 4079 endp--; 4080 } while (endp > path && *endp == '/'); 4081 } 4082 4083 if (endp - path + 2 > PATH_MAX) 4084 { 4085 _rtld_error("Filename is too long: %s", path); 4086 return(-1); 4087 } 4088 4089 strncpy(bname, path, endp - path + 1); 4090 bname[endp - path + 1] = '\0'; 4091 return (0); 4092 } 4093 4094 static int 4095 rtld_dirname_abs(const char *path, char *base) 4096 { 4097 char *last; 4098 4099 if (realpath(path, base) == NULL) { 4100 _rtld_error("realpath \"%s\" failed (%s)", path, 4101 rtld_strerror(errno)); 4102 return (-1); 4103 } 4104 dbg("%s -> %s", path, base); 4105 last = strrchr(base, '/'); 4106 if (last == NULL) { 4107 _rtld_error("non-abs result from realpath \"%s\"", path); 4108 return (-1); 4109 } 4110 if (last != base) 4111 *last = '\0'; 4112 return (0); 4113 } 4114 4115 static void 4116 linkmap_add(Obj_Entry *obj) 4117 { 4118 struct link_map *l, *prev; 4119 4120 l = &obj->linkmap; 4121 l->l_name = obj->path; 4122 l->l_base = obj->mapbase; 4123 l->l_ld = obj->dynamic; 4124 l->l_addr = obj->relocbase; 4125 4126 if (r_debug.r_map == NULL) { 4127 r_debug.r_map = l; 4128 return; 4129 } 4130 4131 /* 4132 * Scan to the end of the list, but not past the entry for the 4133 * dynamic linker, which we want to keep at the very end. 4134 */ 4135 for (prev = r_debug.r_map; 4136 prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap; 4137 prev = prev->l_next) 4138 ; 4139 4140 /* Link in the new entry. */ 4141 l->l_prev = prev; 4142 l->l_next = prev->l_next; 4143 if (l->l_next != NULL) 4144 l->l_next->l_prev = l; 4145 prev->l_next = l; 4146 } 4147 4148 static void 4149 linkmap_delete(Obj_Entry *obj) 4150 { 4151 struct link_map *l; 4152 4153 l = &obj->linkmap; 4154 if (l->l_prev == NULL) { 4155 if ((r_debug.r_map = l->l_next) != NULL) 4156 l->l_next->l_prev = NULL; 4157 return; 4158 } 4159 4160 if ((l->l_prev->l_next = l->l_next) != NULL) 4161 l->l_next->l_prev = l->l_prev; 4162 } 4163 4164 /* 4165 * Function for the debugger to set a breakpoint on to gain control. 4166 * 4167 * The two parameters allow the debugger to easily find and determine 4168 * what the runtime loader is doing and to whom it is doing it. 4169 * 4170 * When the loadhook trap is hit (r_debug_state, set at program 4171 * initialization), the arguments can be found on the stack: 4172 * 4173 * +8 struct link_map *m 4174 * +4 struct r_debug *rd 4175 * +0 RetAddr 4176 */ 4177 void 4178 r_debug_state(struct r_debug* rd __unused, struct link_map *m __unused) 4179 { 4180 /* 4181 * The following is a hack to force the compiler to emit calls to 4182 * this function, even when optimizing. If the function is empty, 4183 * the compiler is not obliged to emit any code for calls to it, 4184 * even when marked __noinline. However, gdb depends on those 4185 * calls being made. 4186 */ 4187 __compiler_membar(); 4188 } 4189 4190 /* 4191 * A function called after init routines have completed. This can be used to 4192 * break before a program's entry routine is called, and can be used when 4193 * main is not available in the symbol table. 4194 */ 4195 void 4196 _r_debug_postinit(struct link_map *m __unused) 4197 { 4198 4199 /* See r_debug_state(). */ 4200 __compiler_membar(); 4201 } 4202 4203 static void 4204 release_object(Obj_Entry *obj) 4205 { 4206 4207 if (obj->holdcount > 0) { 4208 obj->unholdfree = true; 4209 return; 4210 } 4211 munmap(obj->mapbase, obj->mapsize); 4212 linkmap_delete(obj); 4213 obj_free(obj); 4214 } 4215 4216 /* 4217 * Get address of the pointer variable in the main program. 4218 * Prefer non-weak symbol over the weak one. 4219 */ 4220 static const void ** 4221 get_program_var_addr(const char *name, RtldLockState *lockstate) 4222 { 4223 SymLook req; 4224 DoneList donelist; 4225 4226 symlook_init(&req, name); 4227 req.lockstate = lockstate; 4228 donelist_init(&donelist); 4229 if (symlook_global(&req, &donelist) != 0) 4230 return (NULL); 4231 if (ELF_ST_TYPE(req.sym_out->st_info) == STT_FUNC) 4232 return ((const void **)make_function_pointer(req.sym_out, 4233 req.defobj_out)); 4234 else if (ELF_ST_TYPE(req.sym_out->st_info) == STT_GNU_IFUNC) 4235 return ((const void **)rtld_resolve_ifunc(req.defobj_out, req.sym_out)); 4236 else 4237 return ((const void **)(req.defobj_out->relocbase + 4238 req.sym_out->st_value)); 4239 } 4240 4241 /* 4242 * Set a pointer variable in the main program to the given value. This 4243 * is used to set key variables such as "environ" before any of the 4244 * init functions are called. 4245 */ 4246 static void 4247 set_program_var(const char *name, const void *value) 4248 { 4249 const void **addr; 4250 4251 if ((addr = get_program_var_addr(name, NULL)) != NULL) { 4252 dbg("\"%s\": *%p <-- %p", name, addr, value); 4253 *addr = value; 4254 } 4255 } 4256 4257 /* 4258 * Search the global objects, including dependencies and main object, 4259 * for the given symbol. 4260 */ 4261 static int 4262 symlook_global(SymLook *req, DoneList *donelist) 4263 { 4264 SymLook req1; 4265 const Objlist_Entry *elm; 4266 int res; 4267 4268 symlook_init_from_req(&req1, req); 4269 4270 /* Search all objects loaded at program start up. */ 4271 if (req->defobj_out == NULL || 4272 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 4273 res = symlook_list(&req1, &list_main, donelist); 4274 if (res == 0 && (req->defobj_out == NULL || 4275 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4276 req->sym_out = req1.sym_out; 4277 req->defobj_out = req1.defobj_out; 4278 assert(req->defobj_out != NULL); 4279 } 4280 } 4281 4282 /* Search all DAGs whose roots are RTLD_GLOBAL objects. */ 4283 STAILQ_FOREACH(elm, &list_global, link) { 4284 if (req->defobj_out != NULL && 4285 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK) 4286 break; 4287 res = symlook_list(&req1, &elm->obj->dagmembers, donelist); 4288 if (res == 0 && (req->defobj_out == NULL || 4289 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4290 req->sym_out = req1.sym_out; 4291 req->defobj_out = req1.defobj_out; 4292 assert(req->defobj_out != NULL); 4293 } 4294 } 4295 4296 return (req->sym_out != NULL ? 0 : ESRCH); 4297 } 4298 4299 /* 4300 * Given a symbol name in a referencing object, find the corresponding 4301 * definition of the symbol. Returns a pointer to the symbol, or NULL if 4302 * no definition was found. Returns a pointer to the Obj_Entry of the 4303 * defining object via the reference parameter DEFOBJ_OUT. 4304 */ 4305 static int 4306 symlook_default(SymLook *req, const Obj_Entry *refobj) 4307 { 4308 DoneList donelist; 4309 const Objlist_Entry *elm; 4310 SymLook req1; 4311 int res; 4312 4313 donelist_init(&donelist); 4314 symlook_init_from_req(&req1, req); 4315 4316 /* 4317 * Look first in the referencing object if linked symbolically, 4318 * and similarly handle protected symbols. 4319 */ 4320 res = symlook_obj(&req1, refobj); 4321 if (res == 0 && (refobj->symbolic || 4322 ELF_ST_VISIBILITY(req1.sym_out->st_other) == STV_PROTECTED)) { 4323 req->sym_out = req1.sym_out; 4324 req->defobj_out = req1.defobj_out; 4325 assert(req->defobj_out != NULL); 4326 } 4327 if (refobj->symbolic || req->defobj_out != NULL) 4328 donelist_check(&donelist, refobj); 4329 4330 symlook_global(req, &donelist); 4331 4332 /* Search all dlopened DAGs containing the referencing object. */ 4333 STAILQ_FOREACH(elm, &refobj->dldags, link) { 4334 if (req->sym_out != NULL && 4335 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK) 4336 break; 4337 res = symlook_list(&req1, &elm->obj->dagmembers, &donelist); 4338 if (res == 0 && (req->sym_out == NULL || 4339 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4340 req->sym_out = req1.sym_out; 4341 req->defobj_out = req1.defobj_out; 4342 assert(req->defobj_out != NULL); 4343 } 4344 } 4345 4346 /* 4347 * Search the dynamic linker itself, and possibly resolve the 4348 * symbol from there. This is how the application links to 4349 * dynamic linker services such as dlopen. 4350 */ 4351 if (req->sym_out == NULL || 4352 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 4353 res = symlook_obj(&req1, &obj_rtld); 4354 if (res == 0) { 4355 req->sym_out = req1.sym_out; 4356 req->defobj_out = req1.defobj_out; 4357 assert(req->defobj_out != NULL); 4358 } 4359 } 4360 4361 return (req->sym_out != NULL ? 0 : ESRCH); 4362 } 4363 4364 static int 4365 symlook_list(SymLook *req, const Objlist *objlist, DoneList *dlp) 4366 { 4367 const Elf_Sym *def; 4368 const Obj_Entry *defobj; 4369 const Objlist_Entry *elm; 4370 SymLook req1; 4371 int res; 4372 4373 def = NULL; 4374 defobj = NULL; 4375 STAILQ_FOREACH(elm, objlist, link) { 4376 if (donelist_check(dlp, elm->obj)) 4377 continue; 4378 symlook_init_from_req(&req1, req); 4379 if ((res = symlook_obj(&req1, elm->obj)) == 0) { 4380 if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) { 4381 def = req1.sym_out; 4382 defobj = req1.defobj_out; 4383 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 4384 break; 4385 } 4386 } 4387 } 4388 if (def != NULL) { 4389 req->sym_out = def; 4390 req->defobj_out = defobj; 4391 return (0); 4392 } 4393 return (ESRCH); 4394 } 4395 4396 /* 4397 * Search the chain of DAGS cointed to by the given Needed_Entry 4398 * for a symbol of the given name. Each DAG is scanned completely 4399 * before advancing to the next one. Returns a pointer to the symbol, 4400 * or NULL if no definition was found. 4401 */ 4402 static int 4403 symlook_needed(SymLook *req, const Needed_Entry *needed, DoneList *dlp) 4404 { 4405 const Elf_Sym *def; 4406 const Needed_Entry *n; 4407 const Obj_Entry *defobj; 4408 SymLook req1; 4409 int res; 4410 4411 def = NULL; 4412 defobj = NULL; 4413 symlook_init_from_req(&req1, req); 4414 for (n = needed; n != NULL; n = n->next) { 4415 if (n->obj == NULL || 4416 (res = symlook_list(&req1, &n->obj->dagmembers, dlp)) != 0) 4417 continue; 4418 if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) { 4419 def = req1.sym_out; 4420 defobj = req1.defobj_out; 4421 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 4422 break; 4423 } 4424 } 4425 if (def != NULL) { 4426 req->sym_out = def; 4427 req->defobj_out = defobj; 4428 return (0); 4429 } 4430 return (ESRCH); 4431 } 4432 4433 /* 4434 * Search the symbol table of a single shared object for a symbol of 4435 * the given name and version, if requested. Returns a pointer to the 4436 * symbol, or NULL if no definition was found. If the object is 4437 * filter, return filtered symbol from filtee. 4438 * 4439 * The symbol's hash value is passed in for efficiency reasons; that 4440 * eliminates many recomputations of the hash value. 4441 */ 4442 int 4443 symlook_obj(SymLook *req, const Obj_Entry *obj) 4444 { 4445 DoneList donelist; 4446 SymLook req1; 4447 int flags, res, mres; 4448 4449 /* 4450 * If there is at least one valid hash at this point, we prefer to 4451 * use the faster GNU version if available. 4452 */ 4453 if (obj->valid_hash_gnu) 4454 mres = symlook_obj1_gnu(req, obj); 4455 else if (obj->valid_hash_sysv) 4456 mres = symlook_obj1_sysv(req, obj); 4457 else 4458 return (EINVAL); 4459 4460 if (mres == 0) { 4461 if (obj->needed_filtees != NULL) { 4462 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; 4463 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 4464 donelist_init(&donelist); 4465 symlook_init_from_req(&req1, req); 4466 res = symlook_needed(&req1, obj->needed_filtees, &donelist); 4467 if (res == 0) { 4468 req->sym_out = req1.sym_out; 4469 req->defobj_out = req1.defobj_out; 4470 } 4471 return (res); 4472 } 4473 if (obj->needed_aux_filtees != NULL) { 4474 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; 4475 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 4476 donelist_init(&donelist); 4477 symlook_init_from_req(&req1, req); 4478 res = symlook_needed(&req1, obj->needed_aux_filtees, &donelist); 4479 if (res == 0) { 4480 req->sym_out = req1.sym_out; 4481 req->defobj_out = req1.defobj_out; 4482 return (res); 4483 } 4484 } 4485 } 4486 return (mres); 4487 } 4488 4489 /* Symbol match routine common to both hash functions */ 4490 static bool 4491 matched_symbol(SymLook *req, const Obj_Entry *obj, Sym_Match_Result *result, 4492 const unsigned long symnum) 4493 { 4494 Elf_Versym verndx; 4495 const Elf_Sym *symp; 4496 const char *strp; 4497 4498 symp = obj->symtab + symnum; 4499 strp = obj->strtab + symp->st_name; 4500 4501 switch (ELF_ST_TYPE(symp->st_info)) { 4502 case STT_FUNC: 4503 case STT_NOTYPE: 4504 case STT_OBJECT: 4505 case STT_COMMON: 4506 case STT_GNU_IFUNC: 4507 if (symp->st_value == 0) 4508 return (false); 4509 /* fallthrough */ 4510 case STT_TLS: 4511 if (symp->st_shndx != SHN_UNDEF) 4512 break; 4513 #ifndef __mips__ 4514 else if (((req->flags & SYMLOOK_IN_PLT) == 0) && 4515 (ELF_ST_TYPE(symp->st_info) == STT_FUNC)) 4516 break; 4517 #endif 4518 /* fallthrough */ 4519 default: 4520 return (false); 4521 } 4522 if (req->name[0] != strp[0] || strcmp(req->name, strp) != 0) 4523 return (false); 4524 4525 if (req->ventry == NULL) { 4526 if (obj->versyms != NULL) { 4527 verndx = VER_NDX(obj->versyms[symnum]); 4528 if (verndx > obj->vernum) { 4529 _rtld_error( 4530 "%s: symbol %s references wrong version %d", 4531 obj->path, obj->strtab + symnum, verndx); 4532 return (false); 4533 } 4534 /* 4535 * If we are not called from dlsym (i.e. this 4536 * is a normal relocation from unversioned 4537 * binary), accept the symbol immediately if 4538 * it happens to have first version after this 4539 * shared object became versioned. Otherwise, 4540 * if symbol is versioned and not hidden, 4541 * remember it. If it is the only symbol with 4542 * this name exported by the shared object, it 4543 * will be returned as a match by the calling 4544 * function. If symbol is global (verndx < 2) 4545 * accept it unconditionally. 4546 */ 4547 if ((req->flags & SYMLOOK_DLSYM) == 0 && 4548 verndx == VER_NDX_GIVEN) { 4549 result->sym_out = symp; 4550 return (true); 4551 } 4552 else if (verndx >= VER_NDX_GIVEN) { 4553 if ((obj->versyms[symnum] & VER_NDX_HIDDEN) 4554 == 0) { 4555 if (result->vsymp == NULL) 4556 result->vsymp = symp; 4557 result->vcount++; 4558 } 4559 return (false); 4560 } 4561 } 4562 result->sym_out = symp; 4563 return (true); 4564 } 4565 if (obj->versyms == NULL) { 4566 if (object_match_name(obj, req->ventry->name)) { 4567 _rtld_error("%s: object %s should provide version %s " 4568 "for symbol %s", obj_rtld.path, obj->path, 4569 req->ventry->name, obj->strtab + symnum); 4570 return (false); 4571 } 4572 } else { 4573 verndx = VER_NDX(obj->versyms[symnum]); 4574 if (verndx > obj->vernum) { 4575 _rtld_error("%s: symbol %s references wrong version %d", 4576 obj->path, obj->strtab + symnum, verndx); 4577 return (false); 4578 } 4579 if (obj->vertab[verndx].hash != req->ventry->hash || 4580 strcmp(obj->vertab[verndx].name, req->ventry->name)) { 4581 /* 4582 * Version does not match. Look if this is a 4583 * global symbol and if it is not hidden. If 4584 * global symbol (verndx < 2) is available, 4585 * use it. Do not return symbol if we are 4586 * called by dlvsym, because dlvsym looks for 4587 * a specific version and default one is not 4588 * what dlvsym wants. 4589 */ 4590 if ((req->flags & SYMLOOK_DLSYM) || 4591 (verndx >= VER_NDX_GIVEN) || 4592 (obj->versyms[symnum] & VER_NDX_HIDDEN)) 4593 return (false); 4594 } 4595 } 4596 result->sym_out = symp; 4597 return (true); 4598 } 4599 4600 /* 4601 * Search for symbol using SysV hash function. 4602 * obj->buckets is known not to be NULL at this point; the test for this was 4603 * performed with the obj->valid_hash_sysv assignment. 4604 */ 4605 static int 4606 symlook_obj1_sysv(SymLook *req, const Obj_Entry *obj) 4607 { 4608 unsigned long symnum; 4609 Sym_Match_Result matchres; 4610 4611 matchres.sym_out = NULL; 4612 matchres.vsymp = NULL; 4613 matchres.vcount = 0; 4614 4615 for (symnum = obj->buckets[req->hash % obj->nbuckets]; 4616 symnum != STN_UNDEF; symnum = obj->chains[symnum]) { 4617 if (symnum >= obj->nchains) 4618 return (ESRCH); /* Bad object */ 4619 4620 if (matched_symbol(req, obj, &matchres, symnum)) { 4621 req->sym_out = matchres.sym_out; 4622 req->defobj_out = obj; 4623 return (0); 4624 } 4625 } 4626 if (matchres.vcount == 1) { 4627 req->sym_out = matchres.vsymp; 4628 req->defobj_out = obj; 4629 return (0); 4630 } 4631 return (ESRCH); 4632 } 4633 4634 /* Search for symbol using GNU hash function */ 4635 static int 4636 symlook_obj1_gnu(SymLook *req, const Obj_Entry *obj) 4637 { 4638 Elf_Addr bloom_word; 4639 const Elf32_Word *hashval; 4640 Elf32_Word bucket; 4641 Sym_Match_Result matchres; 4642 unsigned int h1, h2; 4643 unsigned long symnum; 4644 4645 matchres.sym_out = NULL; 4646 matchres.vsymp = NULL; 4647 matchres.vcount = 0; 4648 4649 /* Pick right bitmask word from Bloom filter array */ 4650 bloom_word = obj->bloom_gnu[(req->hash_gnu / __ELF_WORD_SIZE) & 4651 obj->maskwords_bm_gnu]; 4652 4653 /* Calculate modulus word size of gnu hash and its derivative */ 4654 h1 = req->hash_gnu & (__ELF_WORD_SIZE - 1); 4655 h2 = ((req->hash_gnu >> obj->shift2_gnu) & (__ELF_WORD_SIZE - 1)); 4656 4657 /* Filter out the "definitely not in set" queries */ 4658 if (((bloom_word >> h1) & (bloom_word >> h2) & 1) == 0) 4659 return (ESRCH); 4660 4661 /* Locate hash chain and corresponding value element*/ 4662 bucket = obj->buckets_gnu[req->hash_gnu % obj->nbuckets_gnu]; 4663 if (bucket == 0) 4664 return (ESRCH); 4665 hashval = &obj->chain_zero_gnu[bucket]; 4666 do { 4667 if (((*hashval ^ req->hash_gnu) >> 1) == 0) { 4668 symnum = hashval - obj->chain_zero_gnu; 4669 if (matched_symbol(req, obj, &matchres, symnum)) { 4670 req->sym_out = matchres.sym_out; 4671 req->defobj_out = obj; 4672 return (0); 4673 } 4674 } 4675 } while ((*hashval++ & 1) == 0); 4676 if (matchres.vcount == 1) { 4677 req->sym_out = matchres.vsymp; 4678 req->defobj_out = obj; 4679 return (0); 4680 } 4681 return (ESRCH); 4682 } 4683 4684 static void 4685 trace_loaded_objects(Obj_Entry *obj) 4686 { 4687 const char *fmt1, *fmt2, *fmt, *main_local, *list_containers; 4688 int c; 4689 4690 if ((main_local = getenv(_LD("TRACE_LOADED_OBJECTS_PROGNAME"))) == NULL) 4691 main_local = ""; 4692 4693 if ((fmt1 = getenv(_LD("TRACE_LOADED_OBJECTS_FMT1"))) == NULL) 4694 fmt1 = "\t%o => %p (%x)\n"; 4695 4696 if ((fmt2 = getenv(_LD("TRACE_LOADED_OBJECTS_FMT2"))) == NULL) 4697 fmt2 = "\t%o (%x)\n"; 4698 4699 list_containers = getenv(_LD("TRACE_LOADED_OBJECTS_ALL")); 4700 4701 for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 4702 Needed_Entry *needed; 4703 const char *name, *path; 4704 bool is_lib; 4705 4706 if (obj->marker) 4707 continue; 4708 if (list_containers && obj->needed != NULL) 4709 rtld_printf("%s:\n", obj->path); 4710 for (needed = obj->needed; needed; needed = needed->next) { 4711 if (needed->obj != NULL) { 4712 if (needed->obj->traced && !list_containers) 4713 continue; 4714 needed->obj->traced = true; 4715 path = needed->obj->path; 4716 } else 4717 path = "not found"; 4718 4719 name = obj->strtab + needed->name; 4720 is_lib = strncmp(name, "lib", 3) == 0; /* XXX - bogus */ 4721 4722 fmt = is_lib ? fmt1 : fmt2; 4723 while ((c = *fmt++) != '\0') { 4724 switch (c) { 4725 default: 4726 rtld_putchar(c); 4727 continue; 4728 case '\\': 4729 switch (c = *fmt) { 4730 case '\0': 4731 continue; 4732 case 'n': 4733 rtld_putchar('\n'); 4734 break; 4735 case 't': 4736 rtld_putchar('\t'); 4737 break; 4738 } 4739 break; 4740 case '%': 4741 switch (c = *fmt) { 4742 case '\0': 4743 continue; 4744 case '%': 4745 default: 4746 rtld_putchar(c); 4747 break; 4748 case 'A': 4749 rtld_putstr(main_local); 4750 break; 4751 case 'a': 4752 rtld_putstr(obj_main->path); 4753 break; 4754 case 'o': 4755 rtld_putstr(name); 4756 break; 4757 #if 0 4758 case 'm': 4759 rtld_printf("%d", sodp->sod_major); 4760 break; 4761 case 'n': 4762 rtld_printf("%d", sodp->sod_minor); 4763 break; 4764 #endif 4765 case 'p': 4766 rtld_putstr(path); 4767 break; 4768 case 'x': 4769 rtld_printf("%p", needed->obj ? needed->obj->mapbase : 4770 0); 4771 break; 4772 } 4773 break; 4774 } 4775 ++fmt; 4776 } 4777 } 4778 } 4779 } 4780 4781 /* 4782 * Unload a dlopened object and its dependencies from memory and from 4783 * our data structures. It is assumed that the DAG rooted in the 4784 * object has already been unreferenced, and that the object has a 4785 * reference count of 0. 4786 */ 4787 static void 4788 unload_object(Obj_Entry *root, RtldLockState *lockstate) 4789 { 4790 Obj_Entry marker, *obj, *next; 4791 4792 assert(root->refcount == 0); 4793 4794 /* 4795 * Pass over the DAG removing unreferenced objects from 4796 * appropriate lists. 4797 */ 4798 unlink_object(root); 4799 4800 /* Unmap all objects that are no longer referenced. */ 4801 for (obj = TAILQ_FIRST(&obj_list); obj != NULL; obj = next) { 4802 next = TAILQ_NEXT(obj, next); 4803 if (obj->marker || obj->refcount != 0) 4804 continue; 4805 LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase, 4806 obj->mapsize, 0, obj->path); 4807 dbg("unloading \"%s\"", obj->path); 4808 /* 4809 * Unlink the object now to prevent new references from 4810 * being acquired while the bind lock is dropped in 4811 * recursive dlclose() invocations. 4812 */ 4813 TAILQ_REMOVE(&obj_list, obj, next); 4814 obj_count--; 4815 4816 if (obj->filtees_loaded) { 4817 if (next != NULL) { 4818 init_marker(&marker); 4819 TAILQ_INSERT_BEFORE(next, &marker, next); 4820 unload_filtees(obj, lockstate); 4821 next = TAILQ_NEXT(&marker, next); 4822 TAILQ_REMOVE(&obj_list, &marker, next); 4823 } else 4824 unload_filtees(obj, lockstate); 4825 } 4826 release_object(obj); 4827 } 4828 } 4829 4830 static void 4831 unlink_object(Obj_Entry *root) 4832 { 4833 Objlist_Entry *elm; 4834 4835 if (root->refcount == 0) { 4836 /* Remove the object from the RTLD_GLOBAL list. */ 4837 objlist_remove(&list_global, root); 4838 4839 /* Remove the object from all objects' DAG lists. */ 4840 STAILQ_FOREACH(elm, &root->dagmembers, link) { 4841 objlist_remove(&elm->obj->dldags, root); 4842 if (elm->obj != root) 4843 unlink_object(elm->obj); 4844 } 4845 } 4846 } 4847 4848 static void 4849 ref_dag(Obj_Entry *root) 4850 { 4851 Objlist_Entry *elm; 4852 4853 assert(root->dag_inited); 4854 STAILQ_FOREACH(elm, &root->dagmembers, link) 4855 elm->obj->refcount++; 4856 } 4857 4858 static void 4859 unref_dag(Obj_Entry *root) 4860 { 4861 Objlist_Entry *elm; 4862 4863 assert(root->dag_inited); 4864 STAILQ_FOREACH(elm, &root->dagmembers, link) 4865 elm->obj->refcount--; 4866 } 4867 4868 /* 4869 * Common code for MD __tls_get_addr(). 4870 */ 4871 static void *tls_get_addr_slow(Elf_Addr **, int, size_t) __noinline; 4872 static void * 4873 tls_get_addr_slow(Elf_Addr **dtvp, int index, size_t offset) 4874 { 4875 Elf_Addr *newdtv, *dtv; 4876 RtldLockState lockstate; 4877 int to_copy; 4878 4879 dtv = *dtvp; 4880 /* Check dtv generation in case new modules have arrived */ 4881 if (dtv[0] != tls_dtv_generation) { 4882 wlock_acquire(rtld_bind_lock, &lockstate); 4883 newdtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4884 to_copy = dtv[1]; 4885 if (to_copy > tls_max_index) 4886 to_copy = tls_max_index; 4887 memcpy(&newdtv[2], &dtv[2], to_copy * sizeof(Elf_Addr)); 4888 newdtv[0] = tls_dtv_generation; 4889 newdtv[1] = tls_max_index; 4890 free(dtv); 4891 lock_release(rtld_bind_lock, &lockstate); 4892 dtv = *dtvp = newdtv; 4893 } 4894 4895 /* Dynamically allocate module TLS if necessary */ 4896 if (dtv[index + 1] == 0) { 4897 /* Signal safe, wlock will block out signals. */ 4898 wlock_acquire(rtld_bind_lock, &lockstate); 4899 if (!dtv[index + 1]) 4900 dtv[index + 1] = (Elf_Addr)allocate_module_tls(index); 4901 lock_release(rtld_bind_lock, &lockstate); 4902 } 4903 return ((void *)(dtv[index + 1] + offset)); 4904 } 4905 4906 void * 4907 tls_get_addr_common(Elf_Addr **dtvp, int index, size_t offset) 4908 { 4909 Elf_Addr *dtv; 4910 4911 dtv = *dtvp; 4912 /* Check dtv generation in case new modules have arrived */ 4913 if (__predict_true(dtv[0] == tls_dtv_generation && 4914 dtv[index + 1] != 0)) 4915 return ((void *)(dtv[index + 1] + offset)); 4916 return (tls_get_addr_slow(dtvp, index, offset)); 4917 } 4918 4919 #if defined(__aarch64__) || defined(__arm__) || defined(__mips__) || \ 4920 defined(__powerpc__) || defined(__riscv) 4921 4922 /* 4923 * Return pointer to allocated TLS block 4924 */ 4925 static void * 4926 get_tls_block_ptr(void *tcb, size_t tcbsize) 4927 { 4928 size_t extra_size, post_size, pre_size, tls_block_size; 4929 size_t tls_init_align; 4930 4931 tls_init_align = MAX(obj_main->tlsalign, 1); 4932 4933 /* Compute fragments sizes. */ 4934 extra_size = tcbsize - TLS_TCB_SIZE; 4935 post_size = calculate_tls_post_size(tls_init_align); 4936 tls_block_size = tcbsize + post_size; 4937 pre_size = roundup2(tls_block_size, tls_init_align) - tls_block_size; 4938 4939 return ((char *)tcb - pre_size - extra_size); 4940 } 4941 4942 /* 4943 * Allocate Static TLS using the Variant I method. 4944 * 4945 * For details on the layout, see lib/libc/gen/tls.c. 4946 * 4947 * NB: rtld's tls_static_space variable includes TLS_TCB_SIZE and post_size as 4948 * it is based on tls_last_offset, and TLS offsets here are really TCB 4949 * offsets, whereas libc's tls_static_space is just the executable's static 4950 * TLS segment. 4951 */ 4952 void * 4953 allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign) 4954 { 4955 Obj_Entry *obj; 4956 char *tls_block; 4957 Elf_Addr *dtv, **tcb; 4958 Elf_Addr addr; 4959 Elf_Addr i; 4960 size_t extra_size, maxalign, post_size, pre_size, tls_block_size; 4961 size_t tls_init_align, tls_init_offset; 4962 4963 if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE) 4964 return (oldtcb); 4965 4966 assert(tcbsize >= TLS_TCB_SIZE); 4967 maxalign = MAX(tcbalign, tls_static_max_align); 4968 tls_init_align = MAX(obj_main->tlsalign, 1); 4969 4970 /* Compute fragmets sizes. */ 4971 extra_size = tcbsize - TLS_TCB_SIZE; 4972 post_size = calculate_tls_post_size(tls_init_align); 4973 tls_block_size = tcbsize + post_size; 4974 pre_size = roundup2(tls_block_size, tls_init_align) - tls_block_size; 4975 tls_block_size += pre_size + tls_static_space - TLS_TCB_SIZE - post_size; 4976 4977 /* Allocate whole TLS block */ 4978 tls_block = malloc_aligned(tls_block_size, maxalign, 0); 4979 tcb = (Elf_Addr **)(tls_block + pre_size + extra_size); 4980 4981 if (oldtcb != NULL) { 4982 memcpy(tls_block, get_tls_block_ptr(oldtcb, tcbsize), 4983 tls_static_space); 4984 free_aligned(get_tls_block_ptr(oldtcb, tcbsize)); 4985 4986 /* Adjust the DTV. */ 4987 dtv = tcb[0]; 4988 for (i = 0; i < dtv[1]; i++) { 4989 if (dtv[i+2] >= (Elf_Addr)oldtcb && 4990 dtv[i+2] < (Elf_Addr)oldtcb + tls_static_space) { 4991 dtv[i+2] = dtv[i+2] - (Elf_Addr)oldtcb + (Elf_Addr)tcb; 4992 } 4993 } 4994 } else { 4995 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4996 tcb[0] = dtv; 4997 dtv[0] = tls_dtv_generation; 4998 dtv[1] = tls_max_index; 4999 5000 for (obj = globallist_curr(objs); obj != NULL; 5001 obj = globallist_next(obj)) { 5002 if (obj->tlsoffset == 0) 5003 continue; 5004 tls_init_offset = obj->tlspoffset & (obj->tlsalign - 1); 5005 addr = (Elf_Addr)tcb + obj->tlsoffset; 5006 if (tls_init_offset > 0) 5007 memset((void *)addr, 0, tls_init_offset); 5008 if (obj->tlsinitsize > 0) { 5009 memcpy((void *)(addr + tls_init_offset), obj->tlsinit, 5010 obj->tlsinitsize); 5011 } 5012 if (obj->tlssize > obj->tlsinitsize) { 5013 memset((void *)(addr + tls_init_offset + obj->tlsinitsize), 5014 0, obj->tlssize - obj->tlsinitsize - tls_init_offset); 5015 } 5016 dtv[obj->tlsindex + 1] = addr; 5017 } 5018 } 5019 5020 return (tcb); 5021 } 5022 5023 void 5024 free_tls(void *tcb, size_t tcbsize, size_t tcbalign __unused) 5025 { 5026 Elf_Addr *dtv; 5027 Elf_Addr tlsstart, tlsend; 5028 size_t post_size; 5029 size_t dtvsize, i, tls_init_align; 5030 5031 assert(tcbsize >= TLS_TCB_SIZE); 5032 tls_init_align = MAX(obj_main->tlsalign, 1); 5033 5034 /* Compute fragments sizes. */ 5035 post_size = calculate_tls_post_size(tls_init_align); 5036 5037 tlsstart = (Elf_Addr)tcb + TLS_TCB_SIZE + post_size; 5038 tlsend = (Elf_Addr)tcb + tls_static_space; 5039 5040 dtv = *(Elf_Addr **)tcb; 5041 dtvsize = dtv[1]; 5042 for (i = 0; i < dtvsize; i++) { 5043 if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] >= tlsend)) { 5044 free((void*)dtv[i+2]); 5045 } 5046 } 5047 free(dtv); 5048 free_aligned(get_tls_block_ptr(tcb, tcbsize)); 5049 } 5050 5051 #endif 5052 5053 #if defined(__i386__) || defined(__amd64__) 5054 5055 /* 5056 * Allocate Static TLS using the Variant II method. 5057 */ 5058 void * 5059 allocate_tls(Obj_Entry *objs, void *oldtls, size_t tcbsize, size_t tcbalign) 5060 { 5061 Obj_Entry *obj; 5062 size_t size, ralign; 5063 char *tls; 5064 Elf_Addr *dtv, *olddtv; 5065 Elf_Addr segbase, oldsegbase, addr; 5066 size_t i; 5067 5068 ralign = tcbalign; 5069 if (tls_static_max_align > ralign) 5070 ralign = tls_static_max_align; 5071 size = roundup(tls_static_space, ralign) + roundup(tcbsize, ralign); 5072 5073 assert(tcbsize >= 2*sizeof(Elf_Addr)); 5074 tls = malloc_aligned(size, ralign, 0 /* XXX */); 5075 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 5076 5077 segbase = (Elf_Addr)(tls + roundup(tls_static_space, ralign)); 5078 ((Elf_Addr*)segbase)[0] = segbase; 5079 ((Elf_Addr*)segbase)[1] = (Elf_Addr) dtv; 5080 5081 dtv[0] = tls_dtv_generation; 5082 dtv[1] = tls_max_index; 5083 5084 if (oldtls) { 5085 /* 5086 * Copy the static TLS block over whole. 5087 */ 5088 oldsegbase = (Elf_Addr) oldtls; 5089 memcpy((void *)(segbase - tls_static_space), 5090 (const void *)(oldsegbase - tls_static_space), 5091 tls_static_space); 5092 5093 /* 5094 * If any dynamic TLS blocks have been created tls_get_addr(), 5095 * move them over. 5096 */ 5097 olddtv = ((Elf_Addr**)oldsegbase)[1]; 5098 for (i = 0; i < olddtv[1]; i++) { 5099 if (olddtv[i+2] < oldsegbase - size || olddtv[i+2] > oldsegbase) { 5100 dtv[i+2] = olddtv[i+2]; 5101 olddtv[i+2] = 0; 5102 } 5103 } 5104 5105 /* 5106 * We assume that this block was the one we created with 5107 * allocate_initial_tls(). 5108 */ 5109 free_tls(oldtls, 2*sizeof(Elf_Addr), sizeof(Elf_Addr)); 5110 } else { 5111 for (obj = objs; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 5112 if (obj->marker || obj->tlsoffset == 0) 5113 continue; 5114 addr = segbase - obj->tlsoffset; 5115 memset((void*)(addr + obj->tlsinitsize), 5116 0, obj->tlssize - obj->tlsinitsize); 5117 if (obj->tlsinit) { 5118 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize); 5119 obj->static_tls_copied = true; 5120 } 5121 dtv[obj->tlsindex + 1] = addr; 5122 } 5123 } 5124 5125 return (void*) segbase; 5126 } 5127 5128 void 5129 free_tls(void *tls, size_t tcbsize __unused, size_t tcbalign) 5130 { 5131 Elf_Addr* dtv; 5132 size_t size, ralign; 5133 int dtvsize, i; 5134 Elf_Addr tlsstart, tlsend; 5135 5136 /* 5137 * Figure out the size of the initial TLS block so that we can 5138 * find stuff which ___tls_get_addr() allocated dynamically. 5139 */ 5140 ralign = tcbalign; 5141 if (tls_static_max_align > ralign) 5142 ralign = tls_static_max_align; 5143 size = roundup(tls_static_space, ralign); 5144 5145 dtv = ((Elf_Addr**)tls)[1]; 5146 dtvsize = dtv[1]; 5147 tlsend = (Elf_Addr) tls; 5148 tlsstart = tlsend - size; 5149 for (i = 0; i < dtvsize; i++) { 5150 if (dtv[i + 2] != 0 && (dtv[i + 2] < tlsstart || dtv[i + 2] > tlsend)) { 5151 free_aligned((void *)dtv[i + 2]); 5152 } 5153 } 5154 5155 free_aligned((void *)tlsstart); 5156 free((void*) dtv); 5157 } 5158 5159 #endif 5160 5161 /* 5162 * Allocate TLS block for module with given index. 5163 */ 5164 void * 5165 allocate_module_tls(int index) 5166 { 5167 Obj_Entry *obj; 5168 char *p; 5169 5170 TAILQ_FOREACH(obj, &obj_list, next) { 5171 if (obj->marker) 5172 continue; 5173 if (obj->tlsindex == index) 5174 break; 5175 } 5176 if (obj == NULL) { 5177 _rtld_error("Can't find module with TLS index %d", index); 5178 rtld_die(); 5179 } 5180 5181 p = malloc_aligned(obj->tlssize, obj->tlsalign, obj->tlspoffset); 5182 memcpy(p, obj->tlsinit, obj->tlsinitsize); 5183 memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize); 5184 return (p); 5185 } 5186 5187 bool 5188 allocate_tls_offset(Obj_Entry *obj) 5189 { 5190 size_t off; 5191 5192 if (obj->tls_done) 5193 return true; 5194 5195 if (obj->tlssize == 0) { 5196 obj->tls_done = true; 5197 return true; 5198 } 5199 5200 if (tls_last_offset == 0) 5201 off = calculate_first_tls_offset(obj->tlssize, obj->tlsalign, 5202 obj->tlspoffset); 5203 else 5204 off = calculate_tls_offset(tls_last_offset, tls_last_size, 5205 obj->tlssize, obj->tlsalign, obj->tlspoffset); 5206 5207 /* 5208 * If we have already fixed the size of the static TLS block, we 5209 * must stay within that size. When allocating the static TLS, we 5210 * leave a small amount of space spare to be used for dynamically 5211 * loading modules which use static TLS. 5212 */ 5213 if (tls_static_space != 0) { 5214 if (calculate_tls_end(off, obj->tlssize) > tls_static_space) 5215 return false; 5216 } else if (obj->tlsalign > tls_static_max_align) { 5217 tls_static_max_align = obj->tlsalign; 5218 } 5219 5220 tls_last_offset = obj->tlsoffset = off; 5221 tls_last_size = obj->tlssize; 5222 obj->tls_done = true; 5223 5224 return true; 5225 } 5226 5227 void 5228 free_tls_offset(Obj_Entry *obj) 5229 { 5230 5231 /* 5232 * If we were the last thing to allocate out of the static TLS 5233 * block, we give our space back to the 'allocator'. This is a 5234 * simplistic workaround to allow libGL.so.1 to be loaded and 5235 * unloaded multiple times. 5236 */ 5237 if (calculate_tls_end(obj->tlsoffset, obj->tlssize) 5238 == calculate_tls_end(tls_last_offset, tls_last_size)) { 5239 tls_last_offset -= obj->tlssize; 5240 tls_last_size = 0; 5241 } 5242 } 5243 5244 void * 5245 _rtld_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign) 5246 { 5247 void *ret; 5248 RtldLockState lockstate; 5249 5250 wlock_acquire(rtld_bind_lock, &lockstate); 5251 ret = allocate_tls(globallist_curr(TAILQ_FIRST(&obj_list)), oldtls, 5252 tcbsize, tcbalign); 5253 lock_release(rtld_bind_lock, &lockstate); 5254 return (ret); 5255 } 5256 5257 void 5258 _rtld_free_tls(void *tcb, size_t tcbsize, size_t tcbalign) 5259 { 5260 RtldLockState lockstate; 5261 5262 wlock_acquire(rtld_bind_lock, &lockstate); 5263 free_tls(tcb, tcbsize, tcbalign); 5264 lock_release(rtld_bind_lock, &lockstate); 5265 } 5266 5267 static void 5268 object_add_name(Obj_Entry *obj, const char *name) 5269 { 5270 Name_Entry *entry; 5271 size_t len; 5272 5273 len = strlen(name); 5274 entry = malloc(sizeof(Name_Entry) + len); 5275 5276 if (entry != NULL) { 5277 strcpy(entry->name, name); 5278 STAILQ_INSERT_TAIL(&obj->names, entry, link); 5279 } 5280 } 5281 5282 static int 5283 object_match_name(const Obj_Entry *obj, const char *name) 5284 { 5285 Name_Entry *entry; 5286 5287 STAILQ_FOREACH(entry, &obj->names, link) { 5288 if (strcmp(name, entry->name) == 0) 5289 return (1); 5290 } 5291 return (0); 5292 } 5293 5294 static Obj_Entry * 5295 locate_dependency(const Obj_Entry *obj, const char *name) 5296 { 5297 const Objlist_Entry *entry; 5298 const Needed_Entry *needed; 5299 5300 STAILQ_FOREACH(entry, &list_main, link) { 5301 if (object_match_name(entry->obj, name)) 5302 return entry->obj; 5303 } 5304 5305 for (needed = obj->needed; needed != NULL; needed = needed->next) { 5306 if (strcmp(obj->strtab + needed->name, name) == 0 || 5307 (needed->obj != NULL && object_match_name(needed->obj, name))) { 5308 /* 5309 * If there is DT_NEEDED for the name we are looking for, 5310 * we are all set. Note that object might not be found if 5311 * dependency was not loaded yet, so the function can 5312 * return NULL here. This is expected and handled 5313 * properly by the caller. 5314 */ 5315 return (needed->obj); 5316 } 5317 } 5318 _rtld_error("%s: Unexpected inconsistency: dependency %s not found", 5319 obj->path, name); 5320 rtld_die(); 5321 } 5322 5323 static int 5324 check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj, 5325 const Elf_Vernaux *vna) 5326 { 5327 const Elf_Verdef *vd; 5328 const char *vername; 5329 5330 vername = refobj->strtab + vna->vna_name; 5331 vd = depobj->verdef; 5332 if (vd == NULL) { 5333 _rtld_error("%s: version %s required by %s not defined", 5334 depobj->path, vername, refobj->path); 5335 return (-1); 5336 } 5337 for (;;) { 5338 if (vd->vd_version != VER_DEF_CURRENT) { 5339 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 5340 depobj->path, vd->vd_version); 5341 return (-1); 5342 } 5343 if (vna->vna_hash == vd->vd_hash) { 5344 const Elf_Verdaux *aux = (const Elf_Verdaux *) 5345 ((const char *)vd + vd->vd_aux); 5346 if (strcmp(vername, depobj->strtab + aux->vda_name) == 0) 5347 return (0); 5348 } 5349 if (vd->vd_next == 0) 5350 break; 5351 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 5352 } 5353 if (vna->vna_flags & VER_FLG_WEAK) 5354 return (0); 5355 _rtld_error("%s: version %s required by %s not found", 5356 depobj->path, vername, refobj->path); 5357 return (-1); 5358 } 5359 5360 static int 5361 rtld_verify_object_versions(Obj_Entry *obj) 5362 { 5363 const Elf_Verneed *vn; 5364 const Elf_Verdef *vd; 5365 const Elf_Verdaux *vda; 5366 const Elf_Vernaux *vna; 5367 const Obj_Entry *depobj; 5368 int maxvernum, vernum; 5369 5370 if (obj->ver_checked) 5371 return (0); 5372 obj->ver_checked = true; 5373 5374 maxvernum = 0; 5375 /* 5376 * Walk over defined and required version records and figure out 5377 * max index used by any of them. Do very basic sanity checking 5378 * while there. 5379 */ 5380 vn = obj->verneed; 5381 while (vn != NULL) { 5382 if (vn->vn_version != VER_NEED_CURRENT) { 5383 _rtld_error("%s: Unsupported version %d of Elf_Verneed entry", 5384 obj->path, vn->vn_version); 5385 return (-1); 5386 } 5387 vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux); 5388 for (;;) { 5389 vernum = VER_NEED_IDX(vna->vna_other); 5390 if (vernum > maxvernum) 5391 maxvernum = vernum; 5392 if (vna->vna_next == 0) 5393 break; 5394 vna = (const Elf_Vernaux *)((const char *)vna + vna->vna_next); 5395 } 5396 if (vn->vn_next == 0) 5397 break; 5398 vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next); 5399 } 5400 5401 vd = obj->verdef; 5402 while (vd != NULL) { 5403 if (vd->vd_version != VER_DEF_CURRENT) { 5404 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 5405 obj->path, vd->vd_version); 5406 return (-1); 5407 } 5408 vernum = VER_DEF_IDX(vd->vd_ndx); 5409 if (vernum > maxvernum) 5410 maxvernum = vernum; 5411 if (vd->vd_next == 0) 5412 break; 5413 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 5414 } 5415 5416 if (maxvernum == 0) 5417 return (0); 5418 5419 /* 5420 * Store version information in array indexable by version index. 5421 * Verify that object version requirements are satisfied along the 5422 * way. 5423 */ 5424 obj->vernum = maxvernum + 1; 5425 obj->vertab = xcalloc(obj->vernum, sizeof(Ver_Entry)); 5426 5427 vd = obj->verdef; 5428 while (vd != NULL) { 5429 if ((vd->vd_flags & VER_FLG_BASE) == 0) { 5430 vernum = VER_DEF_IDX(vd->vd_ndx); 5431 assert(vernum <= maxvernum); 5432 vda = (const Elf_Verdaux *)((const char *)vd + vd->vd_aux); 5433 obj->vertab[vernum].hash = vd->vd_hash; 5434 obj->vertab[vernum].name = obj->strtab + vda->vda_name; 5435 obj->vertab[vernum].file = NULL; 5436 obj->vertab[vernum].flags = 0; 5437 } 5438 if (vd->vd_next == 0) 5439 break; 5440 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 5441 } 5442 5443 vn = obj->verneed; 5444 while (vn != NULL) { 5445 depobj = locate_dependency(obj, obj->strtab + vn->vn_file); 5446 if (depobj == NULL) 5447 return (-1); 5448 vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux); 5449 for (;;) { 5450 if (check_object_provided_version(obj, depobj, vna)) 5451 return (-1); 5452 vernum = VER_NEED_IDX(vna->vna_other); 5453 assert(vernum <= maxvernum); 5454 obj->vertab[vernum].hash = vna->vna_hash; 5455 obj->vertab[vernum].name = obj->strtab + vna->vna_name; 5456 obj->vertab[vernum].file = obj->strtab + vn->vn_file; 5457 obj->vertab[vernum].flags = (vna->vna_other & VER_NEED_HIDDEN) ? 5458 VER_INFO_HIDDEN : 0; 5459 if (vna->vna_next == 0) 5460 break; 5461 vna = (const Elf_Vernaux *)((const char *)vna + vna->vna_next); 5462 } 5463 if (vn->vn_next == 0) 5464 break; 5465 vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next); 5466 } 5467 return 0; 5468 } 5469 5470 static int 5471 rtld_verify_versions(const Objlist *objlist) 5472 { 5473 Objlist_Entry *entry; 5474 int rc; 5475 5476 rc = 0; 5477 STAILQ_FOREACH(entry, objlist, link) { 5478 /* 5479 * Skip dummy objects or objects that have their version requirements 5480 * already checked. 5481 */ 5482 if (entry->obj->strtab == NULL || entry->obj->vertab != NULL) 5483 continue; 5484 if (rtld_verify_object_versions(entry->obj) == -1) { 5485 rc = -1; 5486 if (ld_tracing == NULL) 5487 break; 5488 } 5489 } 5490 if (rc == 0 || ld_tracing != NULL) 5491 rc = rtld_verify_object_versions(&obj_rtld); 5492 return rc; 5493 } 5494 5495 const Ver_Entry * 5496 fetch_ventry(const Obj_Entry *obj, unsigned long symnum) 5497 { 5498 Elf_Versym vernum; 5499 5500 if (obj->vertab) { 5501 vernum = VER_NDX(obj->versyms[symnum]); 5502 if (vernum >= obj->vernum) { 5503 _rtld_error("%s: symbol %s has wrong verneed value %d", 5504 obj->path, obj->strtab + symnum, vernum); 5505 } else if (obj->vertab[vernum].hash != 0) { 5506 return &obj->vertab[vernum]; 5507 } 5508 } 5509 return NULL; 5510 } 5511 5512 int 5513 _rtld_get_stack_prot(void) 5514 { 5515 5516 return (stack_prot); 5517 } 5518 5519 int 5520 _rtld_is_dlopened(void *arg) 5521 { 5522 Obj_Entry *obj; 5523 RtldLockState lockstate; 5524 int res; 5525 5526 rlock_acquire(rtld_bind_lock, &lockstate); 5527 obj = dlcheck(arg); 5528 if (obj == NULL) 5529 obj = obj_from_addr(arg); 5530 if (obj == NULL) { 5531 _rtld_error("No shared object contains address"); 5532 lock_release(rtld_bind_lock, &lockstate); 5533 return (-1); 5534 } 5535 res = obj->dlopened ? 1 : 0; 5536 lock_release(rtld_bind_lock, &lockstate); 5537 return (res); 5538 } 5539 5540 static int 5541 obj_remap_relro(Obj_Entry *obj, int prot) 5542 { 5543 5544 if (obj->relro_size > 0 && mprotect(obj->relro_page, obj->relro_size, 5545 prot) == -1) { 5546 _rtld_error("%s: Cannot set relro protection to %#x: %s", 5547 obj->path, prot, rtld_strerror(errno)); 5548 return (-1); 5549 } 5550 return (0); 5551 } 5552 5553 static int 5554 obj_disable_relro(Obj_Entry *obj) 5555 { 5556 5557 return (obj_remap_relro(obj, PROT_READ | PROT_WRITE)); 5558 } 5559 5560 static int 5561 obj_enforce_relro(Obj_Entry *obj) 5562 { 5563 5564 return (obj_remap_relro(obj, PROT_READ)); 5565 } 5566 5567 static void 5568 map_stacks_exec(RtldLockState *lockstate) 5569 { 5570 void (*thr_map_stacks_exec)(void); 5571 5572 if ((max_stack_flags & PF_X) == 0 || (stack_prot & PROT_EXEC) != 0) 5573 return; 5574 thr_map_stacks_exec = (void (*)(void))(uintptr_t) 5575 get_program_var_addr("__pthread_map_stacks_exec", lockstate); 5576 if (thr_map_stacks_exec != NULL) { 5577 stack_prot |= PROT_EXEC; 5578 thr_map_stacks_exec(); 5579 } 5580 } 5581 5582 static void 5583 distribute_static_tls(Objlist *list, RtldLockState *lockstate) 5584 { 5585 Objlist_Entry *elm; 5586 Obj_Entry *obj; 5587 void (*distrib)(size_t, void *, size_t, size_t); 5588 5589 distrib = (void (*)(size_t, void *, size_t, size_t))(uintptr_t) 5590 get_program_var_addr("__pthread_distribute_static_tls", lockstate); 5591 if (distrib == NULL) 5592 return; 5593 STAILQ_FOREACH(elm, list, link) { 5594 obj = elm->obj; 5595 if (obj->marker || !obj->tls_done || obj->static_tls_copied) 5596 continue; 5597 distrib(obj->tlsoffset, obj->tlsinit, obj->tlsinitsize, 5598 obj->tlssize); 5599 obj->static_tls_copied = true; 5600 } 5601 } 5602 5603 void 5604 symlook_init(SymLook *dst, const char *name) 5605 { 5606 5607 bzero(dst, sizeof(*dst)); 5608 dst->name = name; 5609 dst->hash = elf_hash(name); 5610 dst->hash_gnu = gnu_hash(name); 5611 } 5612 5613 static void 5614 symlook_init_from_req(SymLook *dst, const SymLook *src) 5615 { 5616 5617 dst->name = src->name; 5618 dst->hash = src->hash; 5619 dst->hash_gnu = src->hash_gnu; 5620 dst->ventry = src->ventry; 5621 dst->flags = src->flags; 5622 dst->defobj_out = NULL; 5623 dst->sym_out = NULL; 5624 dst->lockstate = src->lockstate; 5625 } 5626 5627 static int 5628 open_binary_fd(const char *argv0, bool search_in_path, 5629 const char **binpath_res) 5630 { 5631 char *binpath, *pathenv, *pe, *res1; 5632 const char *res; 5633 int fd; 5634 5635 binpath = NULL; 5636 res = NULL; 5637 if (search_in_path && strchr(argv0, '/') == NULL) { 5638 binpath = xmalloc(PATH_MAX); 5639 pathenv = getenv("PATH"); 5640 if (pathenv == NULL) { 5641 _rtld_error("-p and no PATH environment variable"); 5642 rtld_die(); 5643 } 5644 pathenv = strdup(pathenv); 5645 if (pathenv == NULL) { 5646 _rtld_error("Cannot allocate memory"); 5647 rtld_die(); 5648 } 5649 fd = -1; 5650 errno = ENOENT; 5651 while ((pe = strsep(&pathenv, ":")) != NULL) { 5652 if (strlcpy(binpath, pe, PATH_MAX) >= PATH_MAX) 5653 continue; 5654 if (binpath[0] != '\0' && 5655 strlcat(binpath, "/", PATH_MAX) >= PATH_MAX) 5656 continue; 5657 if (strlcat(binpath, argv0, PATH_MAX) >= PATH_MAX) 5658 continue; 5659 fd = open(binpath, O_RDONLY | O_CLOEXEC | O_VERIFY); 5660 if (fd != -1 || errno != ENOENT) { 5661 res = binpath; 5662 break; 5663 } 5664 } 5665 free(pathenv); 5666 } else { 5667 fd = open(argv0, O_RDONLY | O_CLOEXEC | O_VERIFY); 5668 res = argv0; 5669 } 5670 5671 if (fd == -1) { 5672 _rtld_error("Cannot open %s: %s", argv0, rtld_strerror(errno)); 5673 rtld_die(); 5674 } 5675 if (res != NULL && res[0] != '/') { 5676 res1 = xmalloc(PATH_MAX); 5677 if (realpath(res, res1) != NULL) { 5678 if (res != argv0) 5679 free(__DECONST(char *, res)); 5680 res = res1; 5681 } else { 5682 free(res1); 5683 } 5684 } 5685 *binpath_res = res; 5686 return (fd); 5687 } 5688 5689 /* 5690 * Parse a set of command-line arguments. 5691 */ 5692 static int 5693 parse_args(char* argv[], int argc, bool *use_pathp, int *fdp, 5694 const char **argv0) 5695 { 5696 const char *arg; 5697 char machine[64]; 5698 size_t sz; 5699 int arglen, fd, i, j, mib[2]; 5700 char opt; 5701 bool seen_b, seen_f; 5702 5703 dbg("Parsing command-line arguments"); 5704 *use_pathp = false; 5705 *fdp = -1; 5706 seen_b = seen_f = false; 5707 5708 for (i = 1; i < argc; i++ ) { 5709 arg = argv[i]; 5710 dbg("argv[%d]: '%s'", i, arg); 5711 5712 /* 5713 * rtld arguments end with an explicit "--" or with the first 5714 * non-prefixed argument. 5715 */ 5716 if (strcmp(arg, "--") == 0) { 5717 i++; 5718 break; 5719 } 5720 if (arg[0] != '-') 5721 break; 5722 5723 /* 5724 * All other arguments are single-character options that can 5725 * be combined, so we need to search through `arg` for them. 5726 */ 5727 arglen = strlen(arg); 5728 for (j = 1; j < arglen; j++) { 5729 opt = arg[j]; 5730 if (opt == 'h') { 5731 print_usage(argv[0]); 5732 _exit(0); 5733 } else if (opt == 'b') { 5734 if (seen_f) { 5735 _rtld_error("Both -b and -f specified"); 5736 rtld_die(); 5737 } 5738 i++; 5739 *argv0 = argv[i]; 5740 seen_b = true; 5741 break; 5742 } else if (opt == 'f') { 5743 if (seen_b) { 5744 _rtld_error("Both -b and -f specified"); 5745 rtld_die(); 5746 } 5747 5748 /* 5749 * -f XX can be used to specify a 5750 * descriptor for the binary named at 5751 * the command line (i.e., the later 5752 * argument will specify the process 5753 * name but the descriptor is what 5754 * will actually be executed). 5755 * 5756 * -f must be the last option in, e.g., -abcf. 5757 */ 5758 if (j != arglen - 1) { 5759 _rtld_error("Invalid options: %s", arg); 5760 rtld_die(); 5761 } 5762 i++; 5763 fd = parse_integer(argv[i]); 5764 if (fd == -1) { 5765 _rtld_error( 5766 "Invalid file descriptor: '%s'", 5767 argv[i]); 5768 rtld_die(); 5769 } 5770 *fdp = fd; 5771 seen_f = true; 5772 break; 5773 } else if (opt == 'p') { 5774 *use_pathp = true; 5775 } else if (opt == 'v') { 5776 machine[0] = '\0'; 5777 mib[0] = CTL_HW; 5778 mib[1] = HW_MACHINE; 5779 sz = sizeof(machine); 5780 sysctl(mib, nitems(mib), machine, &sz, NULL, 0); 5781 rtld_printf( 5782 "FreeBSD ld-elf.so.1 %s\n" 5783 "FreeBSD_version %d\n" 5784 "Default lib path %s\n" 5785 "Env prefix %s\n" 5786 "Hint file %s\n" 5787 "libmap file %s\n", 5788 machine, 5789 __FreeBSD_version, ld_standard_library_path, 5790 ld_env_prefix, ld_elf_hints_default, 5791 ld_path_libmap_conf); 5792 _exit(0); 5793 } else { 5794 _rtld_error("Invalid argument: '%s'", arg); 5795 print_usage(argv[0]); 5796 rtld_die(); 5797 } 5798 } 5799 } 5800 5801 if (!seen_b) 5802 *argv0 = argv[i]; 5803 return (i); 5804 } 5805 5806 /* 5807 * Parse a file descriptor number without pulling in more of libc (e.g. atoi). 5808 */ 5809 static int 5810 parse_integer(const char *str) 5811 { 5812 static const int RADIX = 10; /* XXXJA: possibly support hex? */ 5813 const char *orig; 5814 int n; 5815 char c; 5816 5817 orig = str; 5818 n = 0; 5819 for (c = *str; c != '\0'; c = *++str) { 5820 if (c < '0' || c > '9') 5821 return (-1); 5822 5823 n *= RADIX; 5824 n += c - '0'; 5825 } 5826 5827 /* Make sure we actually parsed something. */ 5828 if (str == orig) 5829 return (-1); 5830 return (n); 5831 } 5832 5833 static void 5834 print_usage(const char *argv0) 5835 { 5836 5837 rtld_printf( 5838 "Usage: %s [-h] [-b <exe>] [-f <FD>] [-p] [--] <binary> [<args>]\n" 5839 "\n" 5840 "Options:\n" 5841 " -h Display this help message\n" 5842 " -b <exe> Execute <exe> instead of <binary>, arg0 is <binary>\n" 5843 " -f <FD> Execute <FD> instead of searching for <binary>\n" 5844 " -p Search in PATH for named binary\n" 5845 " -v Display identification information\n" 5846 " -- End of RTLD options\n" 5847 " <binary> Name of process to execute\n" 5848 " <args> Arguments to the executed process\n", argv0); 5849 } 5850 5851 /* 5852 * Overrides for libc_pic-provided functions. 5853 */ 5854 5855 int 5856 __getosreldate(void) 5857 { 5858 size_t len; 5859 int oid[2]; 5860 int error, osrel; 5861 5862 if (osreldate != 0) 5863 return (osreldate); 5864 5865 oid[0] = CTL_KERN; 5866 oid[1] = KERN_OSRELDATE; 5867 osrel = 0; 5868 len = sizeof(osrel); 5869 error = sysctl(oid, 2, &osrel, &len, NULL, 0); 5870 if (error == 0 && osrel > 0 && len == sizeof(osrel)) 5871 osreldate = osrel; 5872 return (osreldate); 5873 } 5874 const char * 5875 rtld_strerror(int errnum) 5876 { 5877 5878 if (errnum < 0 || errnum >= sys_nerr) 5879 return ("Unknown error"); 5880 return (sys_errlist[errnum]); 5881 } 5882 5883 /* malloc */ 5884 void * 5885 malloc(size_t nbytes) 5886 { 5887 5888 return (__crt_malloc(nbytes)); 5889 } 5890 5891 void * 5892 calloc(size_t num, size_t size) 5893 { 5894 5895 return (__crt_calloc(num, size)); 5896 } 5897 5898 void 5899 free(void *cp) 5900 { 5901 5902 __crt_free(cp); 5903 } 5904 5905 void * 5906 realloc(void *cp, size_t nbytes) 5907 { 5908 5909 return (__crt_realloc(cp, nbytes)); 5910 } 5911 5912 extern int _rtld_version__FreeBSD_version __exported; 5913 int _rtld_version__FreeBSD_version = __FreeBSD_version; 5914 5915 extern char _rtld_version_laddr_offset __exported; 5916 char _rtld_version_laddr_offset; 5917