1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright 1996, 1997, 1998, 1999, 2000 John D. Polstra. 5 * Copyright 2003 Alexander Kabaev <[email protected]>. 6 * Copyright 2009-2013 Konstantin Belousov <[email protected]>. 7 * Copyright 2012 John Marino <[email protected]>. 8 * Copyright 2014-2017 The FreeBSD Foundation 9 * All rights reserved. 10 * 11 * Portions of this software were developed by Konstantin Belousov 12 * under sponsorship from the FreeBSD Foundation. 13 * 14 * Redistribution and use in source and binary forms, with or without 15 * modification, are permitted provided that the following conditions 16 * are met: 17 * 1. Redistributions of source code must retain the above copyright 18 * notice, this list of conditions and the following disclaimer. 19 * 2. Redistributions in binary form must reproduce the above copyright 20 * notice, this list of conditions and the following disclaimer in the 21 * documentation and/or other materials provided with the distribution. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 24 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 25 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 26 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 27 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 28 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 29 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 30 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 31 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 32 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 33 */ 34 35 /* 36 * Dynamic linker for ELF. 37 * 38 * John Polstra <[email protected]>. 39 */ 40 41 #include <sys/cdefs.h> 42 __FBSDID("$FreeBSD$"); 43 44 #include <sys/param.h> 45 #include <sys/mount.h> 46 #include <sys/mman.h> 47 #include <sys/stat.h> 48 #include <sys/sysctl.h> 49 #include <sys/uio.h> 50 #include <sys/utsname.h> 51 #include <sys/ktrace.h> 52 53 #include <dlfcn.h> 54 #include <err.h> 55 #include <errno.h> 56 #include <fcntl.h> 57 #include <stdarg.h> 58 #include <stdio.h> 59 #include <stdlib.h> 60 #include <string.h> 61 #include <unistd.h> 62 63 #include "debug.h" 64 #include "rtld.h" 65 #include "libmap.h" 66 #include "paths.h" 67 #include "rtld_tls.h" 68 #include "rtld_printf.h" 69 #include "rtld_malloc.h" 70 #include "rtld_utrace.h" 71 #include "notes.h" 72 #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(void); 123 static Obj_Entry *load_object(const char *, int fd, const Obj_Entry *, int); 124 static void map_stacks_exec(RtldLockState *); 125 static int obj_disable_relro(Obj_Entry *); 126 static int obj_enforce_relro(Obj_Entry *); 127 static void objlist_call_fini(Objlist *, Obj_Entry *, RtldLockState *); 128 static void objlist_call_init(Objlist *, RtldLockState *); 129 static void objlist_clear(Objlist *); 130 static Objlist_Entry *objlist_find(Objlist *, const Obj_Entry *); 131 static void objlist_init(Objlist *); 132 static void objlist_push_head(Objlist *, Obj_Entry *); 133 static void objlist_push_tail(Objlist *, Obj_Entry *); 134 static void objlist_put_after(Objlist *, Obj_Entry *, Obj_Entry *); 135 static void objlist_remove(Objlist *, Obj_Entry *); 136 static int open_binary_fd(const char *argv0, bool search_in_path, 137 const char **binpath_res); 138 static int parse_args(char* argv[], int argc, bool *use_pathp, int *fdp, 139 const char **argv0); 140 static int parse_integer(const char *); 141 static void *path_enumerate(const char *, path_enum_proc, const char *, void *); 142 static void print_usage(const char *argv0); 143 static void release_object(Obj_Entry *); 144 static int relocate_object_dag(Obj_Entry *root, bool bind_now, 145 Obj_Entry *rtldobj, int flags, RtldLockState *lockstate); 146 static int relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, 147 int flags, RtldLockState *lockstate); 148 static int relocate_objects(Obj_Entry *, bool, Obj_Entry *, int, 149 RtldLockState *); 150 static int resolve_object_ifunc(Obj_Entry *, bool, int, RtldLockState *); 151 static int rtld_dirname(const char *, char *); 152 static int rtld_dirname_abs(const char *, char *); 153 static void *rtld_dlopen(const char *name, int fd, int mode); 154 static void rtld_exit(void); 155 static void rtld_nop_exit(void); 156 static char *search_library_path(const char *, const char *, const char *, 157 int *); 158 static char *search_library_pathfds(const char *, const char *, int *); 159 static const void **get_program_var_addr(const char *, RtldLockState *); 160 static void set_program_var(const char *, const void *); 161 static int symlook_default(SymLook *, const Obj_Entry *refobj); 162 static int symlook_global(SymLook *, DoneList *); 163 static void symlook_init_from_req(SymLook *, const SymLook *); 164 static int symlook_list(SymLook *, const Objlist *, DoneList *); 165 static int symlook_needed(SymLook *, const Needed_Entry *, DoneList *); 166 static int symlook_obj1_sysv(SymLook *, const Obj_Entry *); 167 static int symlook_obj1_gnu(SymLook *, const Obj_Entry *); 168 static void *tls_get_addr_slow(Elf_Addr **, int, size_t, bool) __noinline; 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 struct r_debug r_debug __exported; /* for GDB; */ 199 static bool libmap_disable; /* Disable libmap */ 200 static bool ld_loadfltr; /* Immediate filters processing */ 201 static char *libmap_override; /* Maps to use in addition to libmap.conf */ 202 static bool trust; /* False for setuid and setgid programs */ 203 static bool dangerous_ld_env; /* True if environment variables have been 204 used to affect the libraries loaded */ 205 bool ld_bind_not; /* Disable PLT update */ 206 static char *ld_bind_now; /* Environment variable for immediate binding */ 207 static char *ld_debug; /* Environment variable for debugging */ 208 static char *ld_library_path; /* Environment variable for search path */ 209 static char *ld_library_dirs; /* Environment variable for library descriptors */ 210 static char *ld_preload; /* Environment variable for libraries to 211 load first */ 212 static const char *ld_elf_hints_path; /* Environment variable for alternative hints path */ 213 static const char *ld_tracing; /* Called from ldd to print libs */ 214 static char *ld_utrace; /* Use utrace() to log events. */ 215 static struct obj_entry_q obj_list; /* Queue of all loaded objects */ 216 static Obj_Entry *obj_main; /* The main program shared object */ 217 static Obj_Entry obj_rtld; /* The dynamic linker shared object */ 218 static unsigned int obj_count; /* Number of objects in obj_list */ 219 static unsigned int obj_loads; /* Number of loads of objects (gen count) */ 220 221 static Objlist list_global = /* Objects dlopened with RTLD_GLOBAL */ 222 STAILQ_HEAD_INITIALIZER(list_global); 223 static Objlist list_main = /* Objects loaded at program startup */ 224 STAILQ_HEAD_INITIALIZER(list_main); 225 static Objlist list_fini = /* Objects needing fini() calls */ 226 STAILQ_HEAD_INITIALIZER(list_fini); 227 228 Elf_Sym sym_zero; /* For resolving undefined weak refs. */ 229 230 #define GDB_STATE(s,m) r_debug.r_state = s; r_debug_state(&r_debug,m); 231 232 extern Elf_Dyn _DYNAMIC; 233 #pragma weak _DYNAMIC 234 235 int dlclose(void *) __exported; 236 char *dlerror(void) __exported; 237 void *dlopen(const char *, int) __exported; 238 void *fdlopen(int, int) __exported; 239 void *dlsym(void *, const char *) __exported; 240 dlfunc_t dlfunc(void *, const char *) __exported; 241 void *dlvsym(void *, const char *, const char *) __exported; 242 int dladdr(const void *, Dl_info *) __exported; 243 void dllockinit(void *, void *(*)(void *), void (*)(void *), void (*)(void *), 244 void (*)(void *), void (*)(void *), void (*)(void *)) __exported; 245 int dlinfo(void *, int , void *) __exported; 246 int dl_iterate_phdr(__dl_iterate_hdr_callback, void *) __exported; 247 int _rtld_addr_phdr(const void *, struct dl_phdr_info *) __exported; 248 int _rtld_get_stack_prot(void) __exported; 249 int _rtld_is_dlopened(void *) __exported; 250 void _rtld_error(const char *, ...) __exported; 251 252 /* Only here to fix -Wmissing-prototypes warnings */ 253 int __getosreldate(void); 254 func_ptr_type _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp); 255 Elf_Addr _rtld_bind(Obj_Entry *obj, Elf_Size reloff); 256 257 258 int npagesizes; 259 static int osreldate; 260 size_t *pagesizes; 261 262 static int stack_prot = PROT_READ | PROT_WRITE | RTLD_DEFAULT_STACK_EXEC; 263 static int max_stack_flags; 264 265 /* 266 * Global declarations normally provided by crt1. The dynamic linker is 267 * not built with crt1, so we have to provide them ourselves. 268 */ 269 char *__progname; 270 char **environ; 271 272 /* 273 * Used to pass argc, argv to init functions. 274 */ 275 int main_argc; 276 char **main_argv; 277 278 /* 279 * Globals to control TLS allocation. 280 */ 281 size_t tls_last_offset; /* Static TLS offset of last module */ 282 size_t tls_last_size; /* Static TLS size of last module */ 283 size_t tls_static_space; /* Static TLS space allocated */ 284 static size_t tls_static_max_align; 285 Elf_Addr tls_dtv_generation = 1; /* Used to detect when dtv size changes */ 286 int tls_max_index = 1; /* Largest module index allocated */ 287 288 static bool ld_library_path_rpath = false; 289 bool ld_fast_sigblock = false; 290 291 /* 292 * Globals for path names, and such 293 */ 294 const char *ld_elf_hints_default = _PATH_ELF_HINTS; 295 const char *ld_path_libmap_conf = _PATH_LIBMAP_CONF; 296 const char *ld_path_rtld = _PATH_RTLD; 297 const char *ld_standard_library_path = STANDARD_LIBRARY_PATH; 298 const char *ld_env_prefix = LD_; 299 300 static void (*rtld_exit_ptr)(void); 301 302 /* 303 * Fill in a DoneList with an allocation large enough to hold all of 304 * the currently-loaded objects. Keep this as a macro since it calls 305 * alloca and we want that to occur within the scope of the caller. 306 */ 307 #define donelist_init(dlp) \ 308 ((dlp)->objs = alloca(obj_count * sizeof (dlp)->objs[0]), \ 309 assert((dlp)->objs != NULL), \ 310 (dlp)->num_alloc = obj_count, \ 311 (dlp)->num_used = 0) 312 313 #define LD_UTRACE(e, h, mb, ms, r, n) do { \ 314 if (ld_utrace != NULL) \ 315 ld_utrace_log(e, h, mb, ms, r, n); \ 316 } while (0) 317 318 static void 319 ld_utrace_log(int event, void *handle, void *mapbase, size_t mapsize, 320 int refcnt, const char *name) 321 { 322 struct utrace_rtld ut; 323 static const char rtld_utrace_sig[RTLD_UTRACE_SIG_SZ] = RTLD_UTRACE_SIG; 324 325 memcpy(ut.sig, rtld_utrace_sig, sizeof(ut.sig)); 326 ut.event = event; 327 ut.handle = handle; 328 ut.mapbase = mapbase; 329 ut.mapsize = mapsize; 330 ut.refcnt = refcnt; 331 bzero(ut.name, sizeof(ut.name)); 332 if (name) 333 strlcpy(ut.name, name, sizeof(ut.name)); 334 utrace(&ut, sizeof(ut)); 335 } 336 337 #ifdef RTLD_VARIANT_ENV_NAMES 338 /* 339 * construct the env variable based on the type of binary that's 340 * running. 341 */ 342 static inline const char * 343 _LD(const char *var) 344 { 345 static char buffer[128]; 346 347 strlcpy(buffer, ld_env_prefix, sizeof(buffer)); 348 strlcat(buffer, var, sizeof(buffer)); 349 return (buffer); 350 } 351 #else 352 #define _LD(x) LD_ x 353 #endif 354 355 /* 356 * Main entry point for dynamic linking. The first argument is the 357 * stack pointer. The stack is expected to be laid out as described 358 * in the SVR4 ABI specification, Intel 386 Processor Supplement. 359 * Specifically, the stack pointer points to a word containing 360 * ARGC. Following that in the stack is a null-terminated sequence 361 * of pointers to argument strings. Then comes a null-terminated 362 * sequence of pointers to environment strings. Finally, there is a 363 * sequence of "auxiliary vector" entries. 364 * 365 * The second argument points to a place to store the dynamic linker's 366 * exit procedure pointer and the third to a place to store the main 367 * program's object. 368 * 369 * The return value is the main program's entry point. 370 */ 371 func_ptr_type 372 _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp) 373 { 374 Elf_Auxinfo *aux, *auxp, *auxpf, *aux_info[AT_COUNT]; 375 Objlist_Entry *entry; 376 Obj_Entry *last_interposer, *obj, *preload_tail; 377 const Elf_Phdr *phdr; 378 Objlist initlist; 379 RtldLockState lockstate; 380 struct stat st; 381 Elf_Addr *argcp; 382 char **argv, **env, **envp, *kexecpath, *library_path_rpath; 383 const char *argv0, *binpath; 384 caddr_t imgentry; 385 char buf[MAXPATHLEN]; 386 int argc, fd, i, mib[4], old_osrel, osrel, phnum, rtld_argc; 387 size_t sz; 388 #ifdef __powerpc__ 389 int old_auxv_format = 1; 390 #endif 391 bool dir_enable, direct_exec, explicit_fd, search_in_path; 392 393 /* 394 * On entry, the dynamic linker itself has not been relocated yet. 395 * Be very careful not to reference any global data until after 396 * init_rtld has returned. It is OK to reference file-scope statics 397 * and string constants, and to call static and global functions. 398 */ 399 400 /* Find the auxiliary vector on the stack. */ 401 argcp = sp; 402 argc = *sp++; 403 argv = (char **) sp; 404 sp += argc + 1; /* Skip over arguments and NULL terminator */ 405 env = (char **) sp; 406 while (*sp++ != 0) /* Skip over environment, and NULL terminator */ 407 ; 408 aux = (Elf_Auxinfo *) sp; 409 410 /* Digest the auxiliary vector. */ 411 for (i = 0; i < AT_COUNT; i++) 412 aux_info[i] = NULL; 413 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) { 414 if (auxp->a_type < AT_COUNT) 415 aux_info[auxp->a_type] = auxp; 416 #ifdef __powerpc__ 417 if (auxp->a_type == 23) /* AT_STACKPROT */ 418 old_auxv_format = 0; 419 #endif 420 } 421 422 #ifdef __powerpc__ 423 if (old_auxv_format) { 424 /* Remap from old-style auxv numbers. */ 425 aux_info[23] = aux_info[21]; /* AT_STACKPROT */ 426 aux_info[21] = aux_info[19]; /* AT_PAGESIZESLEN */ 427 aux_info[19] = aux_info[17]; /* AT_NCPUS */ 428 aux_info[17] = aux_info[15]; /* AT_CANARYLEN */ 429 aux_info[15] = aux_info[13]; /* AT_EXECPATH */ 430 aux_info[13] = NULL; /* AT_GID */ 431 432 aux_info[20] = aux_info[18]; /* AT_PAGESIZES */ 433 aux_info[18] = aux_info[16]; /* AT_OSRELDATE */ 434 aux_info[16] = aux_info[14]; /* AT_CANARY */ 435 aux_info[14] = NULL; /* AT_EGID */ 436 } 437 #endif 438 439 /* Initialize and relocate ourselves. */ 440 assert(aux_info[AT_BASE] != NULL); 441 init_rtld((caddr_t) aux_info[AT_BASE]->a_un.a_ptr, aux_info); 442 443 dlerror_dflt_init(); 444 445 __progname = obj_rtld.path; 446 argv0 = argv[0] != NULL ? argv[0] : "(null)"; 447 environ = env; 448 main_argc = argc; 449 main_argv = argv; 450 451 if (aux_info[AT_BSDFLAGS] != NULL && 452 (aux_info[AT_BSDFLAGS]->a_un.a_val & ELF_BSDF_SIGFASTBLK) != 0) 453 ld_fast_sigblock = true; 454 455 trust = !issetugid(); 456 direct_exec = false; 457 458 md_abi_variant_hook(aux_info); 459 460 fd = -1; 461 if (aux_info[AT_EXECFD] != NULL) { 462 fd = aux_info[AT_EXECFD]->a_un.a_val; 463 } else { 464 assert(aux_info[AT_PHDR] != NULL); 465 phdr = (const Elf_Phdr *)aux_info[AT_PHDR]->a_un.a_ptr; 466 if (phdr == obj_rtld.phdr) { 467 if (!trust) { 468 _rtld_error("Tainted process refusing to run binary %s", 469 argv0); 470 rtld_die(); 471 } 472 direct_exec = true; 473 474 dbg("opening main program in direct exec mode"); 475 if (argc >= 2) { 476 rtld_argc = parse_args(argv, argc, &search_in_path, &fd, &argv0); 477 explicit_fd = (fd != -1); 478 binpath = NULL; 479 if (!explicit_fd) 480 fd = open_binary_fd(argv0, search_in_path, &binpath); 481 if (fstat(fd, &st) == -1) { 482 _rtld_error("Failed to fstat FD %d (%s): %s", fd, 483 explicit_fd ? "user-provided descriptor" : argv0, 484 rtld_strerror(errno)); 485 rtld_die(); 486 } 487 488 /* 489 * Rough emulation of the permission checks done by 490 * execve(2), only Unix DACs are checked, ACLs are 491 * ignored. Preserve the semantic of disabling owner 492 * to execute if owner x bit is cleared, even if 493 * others x bit is enabled. 494 * mmap(2) does not allow to mmap with PROT_EXEC if 495 * binary' file comes from noexec mount. We cannot 496 * set a text reference on the binary. 497 */ 498 dir_enable = false; 499 if (st.st_uid == geteuid()) { 500 if ((st.st_mode & S_IXUSR) != 0) 501 dir_enable = true; 502 } else if (st.st_gid == getegid()) { 503 if ((st.st_mode & S_IXGRP) != 0) 504 dir_enable = true; 505 } else if ((st.st_mode & S_IXOTH) != 0) { 506 dir_enable = true; 507 } 508 if (!dir_enable) { 509 _rtld_error("No execute permission for binary %s", 510 argv0); 511 rtld_die(); 512 } 513 514 /* 515 * For direct exec mode, argv[0] is the interpreter 516 * name, we must remove it and shift arguments left 517 * before invoking binary main. Since stack layout 518 * places environment pointers and aux vectors right 519 * after the terminating NULL, we must shift 520 * environment and aux as well. 521 */ 522 main_argc = argc - rtld_argc; 523 for (i = 0; i <= main_argc; i++) 524 argv[i] = argv[i + rtld_argc]; 525 *argcp -= rtld_argc; 526 environ = env = envp = argv + main_argc + 1; 527 dbg("move env from %p to %p", envp + rtld_argc, envp); 528 do { 529 *envp = *(envp + rtld_argc); 530 } while (*envp++ != NULL); 531 aux = auxp = (Elf_Auxinfo *)envp; 532 auxpf = (Elf_Auxinfo *)(envp + rtld_argc); 533 dbg("move aux from %p to %p", auxpf, aux); 534 /* XXXKIB insert place for AT_EXECPATH if not present */ 535 for (;; auxp++, auxpf++) { 536 *auxp = *auxpf; 537 if (auxp->a_type == AT_NULL) 538 break; 539 } 540 /* Since the auxiliary vector has moved, redigest it. */ 541 for (i = 0; i < AT_COUNT; i++) 542 aux_info[i] = NULL; 543 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) { 544 if (auxp->a_type < AT_COUNT) 545 aux_info[auxp->a_type] = auxp; 546 } 547 548 /* Point AT_EXECPATH auxv and aux_info to the binary path. */ 549 if (binpath == NULL) { 550 aux_info[AT_EXECPATH] = NULL; 551 } else { 552 if (aux_info[AT_EXECPATH] == NULL) { 553 aux_info[AT_EXECPATH] = xmalloc(sizeof(Elf_Auxinfo)); 554 aux_info[AT_EXECPATH]->a_type = AT_EXECPATH; 555 } 556 aux_info[AT_EXECPATH]->a_un.a_ptr = __DECONST(void *, 557 binpath); 558 } 559 } else { 560 _rtld_error("No binary"); 561 rtld_die(); 562 } 563 } 564 } 565 566 ld_bind_now = getenv(_LD("BIND_NOW")); 567 568 /* 569 * If the process is tainted, then we un-set the dangerous environment 570 * variables. The process will be marked as tainted until setuid(2) 571 * is called. If any child process calls setuid(2) we do not want any 572 * future processes to honor the potentially un-safe variables. 573 */ 574 if (!trust) { 575 if (unsetenv(_LD("PRELOAD")) || unsetenv(_LD("LIBMAP")) || 576 unsetenv(_LD("LIBRARY_PATH")) || unsetenv(_LD("LIBRARY_PATH_FDS")) || 577 unsetenv(_LD("LIBMAP_DISABLE")) || unsetenv(_LD("BIND_NOT")) || 578 unsetenv(_LD("DEBUG")) || unsetenv(_LD("ELF_HINTS_PATH")) || 579 unsetenv(_LD("LOADFLTR")) || unsetenv(_LD("LIBRARY_PATH_RPATH"))) { 580 _rtld_error("environment corrupt; aborting"); 581 rtld_die(); 582 } 583 } 584 ld_debug = getenv(_LD("DEBUG")); 585 if (ld_bind_now == NULL) 586 ld_bind_not = getenv(_LD("BIND_NOT")) != NULL; 587 libmap_disable = getenv(_LD("LIBMAP_DISABLE")) != NULL; 588 libmap_override = getenv(_LD("LIBMAP")); 589 ld_library_path = getenv(_LD("LIBRARY_PATH")); 590 ld_library_dirs = getenv(_LD("LIBRARY_PATH_FDS")); 591 ld_preload = getenv(_LD("PRELOAD")); 592 ld_elf_hints_path = getenv(_LD("ELF_HINTS_PATH")); 593 ld_loadfltr = getenv(_LD("LOADFLTR")) != NULL; 594 library_path_rpath = getenv(_LD("LIBRARY_PATH_RPATH")); 595 if (library_path_rpath != NULL) { 596 if (library_path_rpath[0] == 'y' || 597 library_path_rpath[0] == 'Y' || 598 library_path_rpath[0] == '1') 599 ld_library_path_rpath = true; 600 else 601 ld_library_path_rpath = false; 602 } 603 dangerous_ld_env = libmap_disable || (libmap_override != NULL) || 604 (ld_library_path != NULL) || (ld_preload != NULL) || 605 (ld_elf_hints_path != NULL) || ld_loadfltr; 606 ld_tracing = getenv(_LD("TRACE_LOADED_OBJECTS")); 607 ld_utrace = getenv(_LD("UTRACE")); 608 609 if ((ld_elf_hints_path == NULL) || strlen(ld_elf_hints_path) == 0) 610 ld_elf_hints_path = ld_elf_hints_default; 611 612 if (ld_debug != NULL && *ld_debug != '\0') 613 debug = 1; 614 dbg("%s is initialized, base address = %p", __progname, 615 (caddr_t) aux_info[AT_BASE]->a_un.a_ptr); 616 dbg("RTLD dynamic = %p", obj_rtld.dynamic); 617 dbg("RTLD pltgot = %p", obj_rtld.pltgot); 618 619 dbg("initializing thread locks"); 620 lockdflt_init(); 621 622 /* 623 * Load the main program, or process its program header if it is 624 * already loaded. 625 */ 626 if (fd != -1) { /* Load the main program. */ 627 dbg("loading main program"); 628 obj_main = map_object(fd, argv0, NULL); 629 close(fd); 630 if (obj_main == NULL) 631 rtld_die(); 632 max_stack_flags = obj_main->stack_flags; 633 } else { /* Main program already loaded. */ 634 dbg("processing main program's program header"); 635 assert(aux_info[AT_PHDR] != NULL); 636 phdr = (const Elf_Phdr *) aux_info[AT_PHDR]->a_un.a_ptr; 637 assert(aux_info[AT_PHNUM] != NULL); 638 phnum = aux_info[AT_PHNUM]->a_un.a_val; 639 assert(aux_info[AT_PHENT] != NULL); 640 assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr)); 641 assert(aux_info[AT_ENTRY] != NULL); 642 imgentry = (caddr_t) aux_info[AT_ENTRY]->a_un.a_ptr; 643 if ((obj_main = digest_phdr(phdr, phnum, imgentry, argv0)) == NULL) 644 rtld_die(); 645 } 646 647 if (aux_info[AT_EXECPATH] != NULL && fd == -1) { 648 kexecpath = aux_info[AT_EXECPATH]->a_un.a_ptr; 649 dbg("AT_EXECPATH %p %s", kexecpath, kexecpath); 650 if (kexecpath[0] == '/') 651 obj_main->path = kexecpath; 652 else if (getcwd(buf, sizeof(buf)) == NULL || 653 strlcat(buf, "/", sizeof(buf)) >= sizeof(buf) || 654 strlcat(buf, kexecpath, sizeof(buf)) >= sizeof(buf)) 655 obj_main->path = xstrdup(argv0); 656 else 657 obj_main->path = xstrdup(buf); 658 } else { 659 dbg("No AT_EXECPATH or direct exec"); 660 obj_main->path = xstrdup(argv0); 661 } 662 dbg("obj_main path %s", obj_main->path); 663 obj_main->mainprog = true; 664 665 if (aux_info[AT_STACKPROT] != NULL && 666 aux_info[AT_STACKPROT]->a_un.a_val != 0) 667 stack_prot = aux_info[AT_STACKPROT]->a_un.a_val; 668 669 #ifndef COMPAT_32BIT 670 /* 671 * Get the actual dynamic linker pathname from the executable if 672 * possible. (It should always be possible.) That ensures that 673 * gdb will find the right dynamic linker even if a non-standard 674 * one is being used. 675 */ 676 if (obj_main->interp != NULL && 677 strcmp(obj_main->interp, obj_rtld.path) != 0) { 678 free(obj_rtld.path); 679 obj_rtld.path = xstrdup(obj_main->interp); 680 __progname = obj_rtld.path; 681 } 682 #endif 683 684 if (!digest_dynamic(obj_main, 0)) 685 rtld_die(); 686 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", 687 obj_main->path, obj_main->valid_hash_sysv, obj_main->valid_hash_gnu, 688 obj_main->dynsymcount); 689 690 linkmap_add(obj_main); 691 linkmap_add(&obj_rtld); 692 693 /* Link the main program into the list of objects. */ 694 TAILQ_INSERT_HEAD(&obj_list, obj_main, next); 695 obj_count++; 696 obj_loads++; 697 698 /* Initialize a fake symbol for resolving undefined weak references. */ 699 sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE); 700 sym_zero.st_shndx = SHN_UNDEF; 701 sym_zero.st_value = -(uintptr_t)obj_main->relocbase; 702 703 if (!libmap_disable) 704 libmap_disable = (bool)lm_init(libmap_override); 705 706 dbg("loading LD_PRELOAD libraries"); 707 if (load_preload_objects() == -1) 708 rtld_die(); 709 preload_tail = globallist_curr(TAILQ_LAST(&obj_list, obj_entry_q)); 710 711 dbg("loading needed objects"); 712 if (load_needed_objects(obj_main, ld_tracing != NULL ? RTLD_LO_TRACE : 713 0) == -1) 714 rtld_die(); 715 716 /* Make a list of all objects loaded at startup. */ 717 last_interposer = obj_main; 718 TAILQ_FOREACH(obj, &obj_list, next) { 719 if (obj->marker) 720 continue; 721 if (obj->z_interpose && obj != obj_main) { 722 objlist_put_after(&list_main, last_interposer, obj); 723 last_interposer = obj; 724 } else { 725 objlist_push_tail(&list_main, obj); 726 } 727 obj->refcount++; 728 } 729 730 dbg("checking for required versions"); 731 if (rtld_verify_versions(&list_main) == -1 && !ld_tracing) 732 rtld_die(); 733 734 if (ld_tracing) { /* We're done */ 735 trace_loaded_objects(obj_main); 736 exit(0); 737 } 738 739 if (getenv(_LD("DUMP_REL_PRE")) != NULL) { 740 dump_relocations(obj_main); 741 exit (0); 742 } 743 744 /* 745 * Processing tls relocations requires having the tls offsets 746 * initialized. Prepare offsets before starting initial 747 * relocation processing. 748 */ 749 dbg("initializing initial thread local storage offsets"); 750 STAILQ_FOREACH(entry, &list_main, link) { 751 /* 752 * Allocate all the initial objects out of the static TLS 753 * block even if they didn't ask for it. 754 */ 755 allocate_tls_offset(entry->obj); 756 } 757 758 if (relocate_objects(obj_main, 759 ld_bind_now != NULL && *ld_bind_now != '\0', 760 &obj_rtld, SYMLOOK_EARLY, NULL) == -1) 761 rtld_die(); 762 763 dbg("doing copy relocations"); 764 if (do_copy_relocations(obj_main) == -1) 765 rtld_die(); 766 767 if (getenv(_LD("DUMP_REL_POST")) != NULL) { 768 dump_relocations(obj_main); 769 exit (0); 770 } 771 772 ifunc_init(aux); 773 774 /* 775 * Setup TLS for main thread. This must be done after the 776 * relocations are processed, since tls initialization section 777 * might be the subject for relocations. 778 */ 779 dbg("initializing initial thread local storage"); 780 allocate_initial_tls(globallist_curr(TAILQ_FIRST(&obj_list))); 781 782 dbg("initializing key program variables"); 783 set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : ""); 784 set_program_var("environ", env); 785 set_program_var("__elf_aux_vector", aux); 786 787 /* Make a list of init functions to call. */ 788 objlist_init(&initlist); 789 initlist_add_objects(globallist_curr(TAILQ_FIRST(&obj_list)), 790 preload_tail, &initlist); 791 792 r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */ 793 794 map_stacks_exec(NULL); 795 796 if (!obj_main->crt_no_init) { 797 /* 798 * Make sure we don't call the main program's init and fini 799 * functions for binaries linked with old crt1 which calls 800 * _init itself. 801 */ 802 obj_main->init = obj_main->fini = (Elf_Addr)NULL; 803 obj_main->preinit_array = obj_main->init_array = 804 obj_main->fini_array = (Elf_Addr)NULL; 805 } 806 807 if (direct_exec) { 808 /* Set osrel for direct-execed binary */ 809 mib[0] = CTL_KERN; 810 mib[1] = KERN_PROC; 811 mib[2] = KERN_PROC_OSREL; 812 mib[3] = getpid(); 813 osrel = obj_main->osrel; 814 sz = sizeof(old_osrel); 815 dbg("setting osrel to %d", osrel); 816 (void)sysctl(mib, 4, &old_osrel, &sz, &osrel, sizeof(osrel)); 817 } 818 819 wlock_acquire(rtld_bind_lock, &lockstate); 820 821 dbg("resolving ifuncs"); 822 if (initlist_objects_ifunc(&initlist, ld_bind_now != NULL && 823 *ld_bind_now != '\0', SYMLOOK_EARLY, &lockstate) == -1) 824 rtld_die(); 825 826 rtld_exit_ptr = rtld_exit; 827 if (obj_main->crt_no_init) 828 preinit_main(); 829 objlist_call_init(&initlist, &lockstate); 830 _r_debug_postinit(&obj_main->linkmap); 831 objlist_clear(&initlist); 832 dbg("loading filtees"); 833 TAILQ_FOREACH(obj, &obj_list, next) { 834 if (obj->marker) 835 continue; 836 if (ld_loadfltr || obj->z_loadfltr) 837 load_filtees(obj, 0, &lockstate); 838 } 839 840 dbg("enforcing main obj relro"); 841 if (obj_enforce_relro(obj_main) == -1) 842 rtld_die(); 843 844 lock_release(rtld_bind_lock, &lockstate); 845 846 dbg("transferring control to program entry point = %p", obj_main->entry); 847 848 /* Return the exit procedure and the program entry point. */ 849 *exit_proc = rtld_exit_ptr; 850 *objp = obj_main; 851 return (func_ptr_type) obj_main->entry; 852 } 853 854 void * 855 rtld_resolve_ifunc(const Obj_Entry *obj, const Elf_Sym *def) 856 { 857 void *ptr; 858 Elf_Addr target; 859 860 ptr = (void *)make_function_pointer(def, obj); 861 target = call_ifunc_resolver(ptr); 862 return ((void *)target); 863 } 864 865 /* 866 * NB: MIPS uses a private version of this function (_mips_rtld_bind). 867 * Changes to this function should be applied there as well. 868 */ 869 Elf_Addr 870 _rtld_bind(Obj_Entry *obj, Elf_Size reloff) 871 { 872 const Elf_Rel *rel; 873 const Elf_Sym *def; 874 const Obj_Entry *defobj; 875 Elf_Addr *where; 876 Elf_Addr target; 877 RtldLockState lockstate; 878 879 rlock_acquire(rtld_bind_lock, &lockstate); 880 if (sigsetjmp(lockstate.env, 0) != 0) 881 lock_upgrade(rtld_bind_lock, &lockstate); 882 if (obj->pltrel) 883 rel = (const Elf_Rel *)((const char *)obj->pltrel + reloff); 884 else 885 rel = (const Elf_Rel *)((const char *)obj->pltrela + reloff); 886 887 where = (Elf_Addr *)(obj->relocbase + rel->r_offset); 888 def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, SYMLOOK_IN_PLT, 889 NULL, &lockstate); 890 if (def == NULL) 891 rtld_die(); 892 if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 893 target = (Elf_Addr)rtld_resolve_ifunc(defobj, def); 894 else 895 target = (Elf_Addr)(defobj->relocbase + def->st_value); 896 897 dbg("\"%s\" in \"%s\" ==> %p in \"%s\"", 898 defobj->strtab + def->st_name, 899 obj->path == NULL ? NULL : basename(obj->path), 900 (void *)target, 901 defobj->path == NULL ? NULL : basename(defobj->path)); 902 903 /* 904 * Write the new contents for the jmpslot. Note that depending on 905 * architecture, the value which we need to return back to the 906 * lazy binding trampoline may or may not be the target 907 * address. The value returned from reloc_jmpslot() is the value 908 * that the trampoline needs. 909 */ 910 target = reloc_jmpslot(where, target, defobj, obj, rel); 911 lock_release(rtld_bind_lock, &lockstate); 912 return target; 913 } 914 915 /* 916 * Error reporting function. Use it like printf. If formats the message 917 * into a buffer, and sets things up so that the next call to dlerror() 918 * will return the message. 919 */ 920 void 921 _rtld_error(const char *fmt, ...) 922 { 923 va_list ap; 924 925 va_start(ap, fmt); 926 rtld_vsnprintf(lockinfo.dlerror_loc(), lockinfo.dlerror_loc_sz, 927 fmt, ap); 928 va_end(ap); 929 *lockinfo.dlerror_seen() = 0; 930 LD_UTRACE(UTRACE_RTLD_ERROR, NULL, NULL, 0, 0, lockinfo.dlerror_loc()); 931 } 932 933 /* 934 * Return a dynamically-allocated copy of the current error message, if any. 935 */ 936 static char * 937 errmsg_save(void) 938 { 939 return (xstrdup(lockinfo.dlerror_loc())); 940 } 941 942 /* 943 * Restore the current error message from a copy which was previously saved 944 * by errmsg_save(). The copy is freed. 945 */ 946 static void 947 errmsg_restore(char *saved_msg) 948 { 949 if (saved_msg == NULL) 950 _rtld_error(""); 951 else { 952 _rtld_error("%s", saved_msg); 953 free(saved_msg); 954 } 955 } 956 957 static const char * 958 basename(const char *name) 959 { 960 const char *p = strrchr(name, '/'); 961 return p != NULL ? p + 1 : name; 962 } 963 964 static struct utsname uts; 965 966 static char * 967 origin_subst_one(Obj_Entry *obj, char *real, const char *kw, 968 const char *subst, bool may_free) 969 { 970 char *p, *p1, *res, *resp; 971 int subst_len, kw_len, subst_count, old_len, new_len; 972 973 kw_len = strlen(kw); 974 975 /* 976 * First, count the number of the keyword occurrences, to 977 * preallocate the final string. 978 */ 979 for (p = real, subst_count = 0;; p = p1 + kw_len, subst_count++) { 980 p1 = strstr(p, kw); 981 if (p1 == NULL) 982 break; 983 } 984 985 /* 986 * If the keyword is not found, just return. 987 * 988 * Return non-substituted string if resolution failed. We 989 * cannot do anything more reasonable, the failure mode of the 990 * caller is unresolved library anyway. 991 */ 992 if (subst_count == 0 || (obj != NULL && !obj_resolve_origin(obj))) 993 return (may_free ? real : xstrdup(real)); 994 if (obj != NULL) 995 subst = obj->origin_path; 996 997 /* 998 * There is indeed something to substitute. Calculate the 999 * length of the resulting string, and allocate it. 1000 */ 1001 subst_len = strlen(subst); 1002 old_len = strlen(real); 1003 new_len = old_len + (subst_len - kw_len) * subst_count; 1004 res = xmalloc(new_len + 1); 1005 1006 /* 1007 * Now, execute the substitution loop. 1008 */ 1009 for (p = real, resp = res, *resp = '\0';;) { 1010 p1 = strstr(p, kw); 1011 if (p1 != NULL) { 1012 /* Copy the prefix before keyword. */ 1013 memcpy(resp, p, p1 - p); 1014 resp += p1 - p; 1015 /* Keyword replacement. */ 1016 memcpy(resp, subst, subst_len); 1017 resp += subst_len; 1018 *resp = '\0'; 1019 p = p1 + kw_len; 1020 } else 1021 break; 1022 } 1023 1024 /* Copy to the end of string and finish. */ 1025 strcat(resp, p); 1026 if (may_free) 1027 free(real); 1028 return (res); 1029 } 1030 1031 static char * 1032 origin_subst(Obj_Entry *obj, const char *real) 1033 { 1034 char *res1, *res2, *res3, *res4; 1035 1036 if (obj == NULL || !trust) 1037 return (xstrdup(real)); 1038 if (uts.sysname[0] == '\0') { 1039 if (uname(&uts) != 0) { 1040 _rtld_error("utsname failed: %d", errno); 1041 return (NULL); 1042 } 1043 } 1044 /* __DECONST is safe here since without may_free real is unchanged */ 1045 res1 = origin_subst_one(obj, __DECONST(char *, real), "$ORIGIN", NULL, 1046 false); 1047 res2 = origin_subst_one(NULL, res1, "$OSNAME", uts.sysname, true); 1048 res3 = origin_subst_one(NULL, res2, "$OSREL", uts.release, true); 1049 res4 = origin_subst_one(NULL, res3, "$PLATFORM", uts.machine, true); 1050 return (res4); 1051 } 1052 1053 void 1054 rtld_die(void) 1055 { 1056 const char *msg = dlerror(); 1057 1058 if (msg == NULL) 1059 msg = "Fatal error"; 1060 rtld_fdputstr(STDERR_FILENO, _BASENAME_RTLD ": "); 1061 rtld_fdputstr(STDERR_FILENO, msg); 1062 rtld_fdputchar(STDERR_FILENO, '\n'); 1063 _exit(1); 1064 } 1065 1066 /* 1067 * Process a shared object's DYNAMIC section, and save the important 1068 * information in its Obj_Entry structure. 1069 */ 1070 static void 1071 digest_dynamic1(Obj_Entry *obj, int early, const Elf_Dyn **dyn_rpath, 1072 const Elf_Dyn **dyn_soname, const Elf_Dyn **dyn_runpath) 1073 { 1074 const Elf_Dyn *dynp; 1075 Needed_Entry **needed_tail = &obj->needed; 1076 Needed_Entry **needed_filtees_tail = &obj->needed_filtees; 1077 Needed_Entry **needed_aux_filtees_tail = &obj->needed_aux_filtees; 1078 const Elf_Hashelt *hashtab; 1079 const Elf32_Word *hashval; 1080 Elf32_Word bkt, nmaskwords; 1081 int bloom_size32; 1082 int plttype = DT_REL; 1083 1084 *dyn_rpath = NULL; 1085 *dyn_soname = NULL; 1086 *dyn_runpath = NULL; 1087 1088 obj->bind_now = false; 1089 dynp = obj->dynamic; 1090 if (dynp == NULL) 1091 return; 1092 for (; dynp->d_tag != DT_NULL; dynp++) { 1093 switch (dynp->d_tag) { 1094 1095 case DT_REL: 1096 obj->rel = (const Elf_Rel *)(obj->relocbase + dynp->d_un.d_ptr); 1097 break; 1098 1099 case DT_RELSZ: 1100 obj->relsize = dynp->d_un.d_val; 1101 break; 1102 1103 case DT_RELENT: 1104 assert(dynp->d_un.d_val == sizeof(Elf_Rel)); 1105 break; 1106 1107 case DT_JMPREL: 1108 obj->pltrel = (const Elf_Rel *) 1109 (obj->relocbase + dynp->d_un.d_ptr); 1110 break; 1111 1112 case DT_PLTRELSZ: 1113 obj->pltrelsize = dynp->d_un.d_val; 1114 break; 1115 1116 case DT_RELA: 1117 obj->rela = (const Elf_Rela *)(obj->relocbase + dynp->d_un.d_ptr); 1118 break; 1119 1120 case DT_RELASZ: 1121 obj->relasize = dynp->d_un.d_val; 1122 break; 1123 1124 case DT_RELAENT: 1125 assert(dynp->d_un.d_val == sizeof(Elf_Rela)); 1126 break; 1127 1128 case DT_PLTREL: 1129 plttype = dynp->d_un.d_val; 1130 assert(dynp->d_un.d_val == DT_REL || plttype == DT_RELA); 1131 break; 1132 1133 case DT_SYMTAB: 1134 obj->symtab = (const Elf_Sym *) 1135 (obj->relocbase + dynp->d_un.d_ptr); 1136 break; 1137 1138 case DT_SYMENT: 1139 assert(dynp->d_un.d_val == sizeof(Elf_Sym)); 1140 break; 1141 1142 case DT_STRTAB: 1143 obj->strtab = (const char *)(obj->relocbase + dynp->d_un.d_ptr); 1144 break; 1145 1146 case DT_STRSZ: 1147 obj->strsize = dynp->d_un.d_val; 1148 break; 1149 1150 case DT_VERNEED: 1151 obj->verneed = (const Elf_Verneed *)(obj->relocbase + 1152 dynp->d_un.d_val); 1153 break; 1154 1155 case DT_VERNEEDNUM: 1156 obj->verneednum = dynp->d_un.d_val; 1157 break; 1158 1159 case DT_VERDEF: 1160 obj->verdef = (const Elf_Verdef *)(obj->relocbase + 1161 dynp->d_un.d_val); 1162 break; 1163 1164 case DT_VERDEFNUM: 1165 obj->verdefnum = dynp->d_un.d_val; 1166 break; 1167 1168 case DT_VERSYM: 1169 obj->versyms = (const Elf_Versym *)(obj->relocbase + 1170 dynp->d_un.d_val); 1171 break; 1172 1173 case DT_HASH: 1174 { 1175 hashtab = (const Elf_Hashelt *)(obj->relocbase + 1176 dynp->d_un.d_ptr); 1177 obj->nbuckets = hashtab[0]; 1178 obj->nchains = hashtab[1]; 1179 obj->buckets = hashtab + 2; 1180 obj->chains = obj->buckets + obj->nbuckets; 1181 obj->valid_hash_sysv = obj->nbuckets > 0 && obj->nchains > 0 && 1182 obj->buckets != NULL; 1183 } 1184 break; 1185 1186 case DT_GNU_HASH: 1187 { 1188 hashtab = (const Elf_Hashelt *)(obj->relocbase + 1189 dynp->d_un.d_ptr); 1190 obj->nbuckets_gnu = hashtab[0]; 1191 obj->symndx_gnu = hashtab[1]; 1192 nmaskwords = hashtab[2]; 1193 bloom_size32 = (__ELF_WORD_SIZE / 32) * nmaskwords; 1194 obj->maskwords_bm_gnu = nmaskwords - 1; 1195 obj->shift2_gnu = hashtab[3]; 1196 obj->bloom_gnu = (const Elf_Addr *)(hashtab + 4); 1197 obj->buckets_gnu = hashtab + 4 + bloom_size32; 1198 obj->chain_zero_gnu = obj->buckets_gnu + obj->nbuckets_gnu - 1199 obj->symndx_gnu; 1200 /* Number of bitmask words is required to be power of 2 */ 1201 obj->valid_hash_gnu = powerof2(nmaskwords) && 1202 obj->nbuckets_gnu > 0 && obj->buckets_gnu != NULL; 1203 } 1204 break; 1205 1206 case DT_NEEDED: 1207 if (!obj->rtld) { 1208 Needed_Entry *nep = NEW(Needed_Entry); 1209 nep->name = dynp->d_un.d_val; 1210 nep->obj = NULL; 1211 nep->next = NULL; 1212 1213 *needed_tail = nep; 1214 needed_tail = &nep->next; 1215 } 1216 break; 1217 1218 case DT_FILTER: 1219 if (!obj->rtld) { 1220 Needed_Entry *nep = NEW(Needed_Entry); 1221 nep->name = dynp->d_un.d_val; 1222 nep->obj = NULL; 1223 nep->next = NULL; 1224 1225 *needed_filtees_tail = nep; 1226 needed_filtees_tail = &nep->next; 1227 1228 if (obj->linkmap.l_refname == NULL) 1229 obj->linkmap.l_refname = (char *)dynp->d_un.d_val; 1230 } 1231 break; 1232 1233 case DT_AUXILIARY: 1234 if (!obj->rtld) { 1235 Needed_Entry *nep = NEW(Needed_Entry); 1236 nep->name = dynp->d_un.d_val; 1237 nep->obj = NULL; 1238 nep->next = NULL; 1239 1240 *needed_aux_filtees_tail = nep; 1241 needed_aux_filtees_tail = &nep->next; 1242 } 1243 break; 1244 1245 case DT_PLTGOT: 1246 obj->pltgot = (Elf_Addr *)(obj->relocbase + dynp->d_un.d_ptr); 1247 break; 1248 1249 case DT_TEXTREL: 1250 obj->textrel = true; 1251 break; 1252 1253 case DT_SYMBOLIC: 1254 obj->symbolic = true; 1255 break; 1256 1257 case DT_RPATH: 1258 /* 1259 * We have to wait until later to process this, because we 1260 * might not have gotten the address of the string table yet. 1261 */ 1262 *dyn_rpath = dynp; 1263 break; 1264 1265 case DT_SONAME: 1266 *dyn_soname = dynp; 1267 break; 1268 1269 case DT_RUNPATH: 1270 *dyn_runpath = dynp; 1271 break; 1272 1273 case DT_INIT: 1274 obj->init = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1275 break; 1276 1277 case DT_PREINIT_ARRAY: 1278 obj->preinit_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1279 break; 1280 1281 case DT_PREINIT_ARRAYSZ: 1282 obj->preinit_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1283 break; 1284 1285 case DT_INIT_ARRAY: 1286 obj->init_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1287 break; 1288 1289 case DT_INIT_ARRAYSZ: 1290 obj->init_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1291 break; 1292 1293 case DT_FINI: 1294 obj->fini = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1295 break; 1296 1297 case DT_FINI_ARRAY: 1298 obj->fini_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1299 break; 1300 1301 case DT_FINI_ARRAYSZ: 1302 obj->fini_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1303 break; 1304 1305 /* 1306 * Don't process DT_DEBUG on MIPS as the dynamic section 1307 * is mapped read-only. DT_MIPS_RLD_MAP is used instead. 1308 */ 1309 1310 #ifndef __mips__ 1311 case DT_DEBUG: 1312 if (!early) 1313 dbg("Filling in DT_DEBUG entry"); 1314 (__DECONST(Elf_Dyn *, dynp))->d_un.d_ptr = (Elf_Addr)&r_debug; 1315 break; 1316 #endif 1317 1318 case DT_FLAGS: 1319 if (dynp->d_un.d_val & DF_ORIGIN) 1320 obj->z_origin = true; 1321 if (dynp->d_un.d_val & DF_SYMBOLIC) 1322 obj->symbolic = true; 1323 if (dynp->d_un.d_val & DF_TEXTREL) 1324 obj->textrel = true; 1325 if (dynp->d_un.d_val & DF_BIND_NOW) 1326 obj->bind_now = true; 1327 if (dynp->d_un.d_val & DF_STATIC_TLS) 1328 obj->static_tls = true; 1329 break; 1330 #ifdef __mips__ 1331 case DT_MIPS_LOCAL_GOTNO: 1332 obj->local_gotno = dynp->d_un.d_val; 1333 break; 1334 1335 case DT_MIPS_SYMTABNO: 1336 obj->symtabno = dynp->d_un.d_val; 1337 break; 1338 1339 case DT_MIPS_GOTSYM: 1340 obj->gotsym = dynp->d_un.d_val; 1341 break; 1342 1343 case DT_MIPS_RLD_MAP: 1344 *((Elf_Addr *)(dynp->d_un.d_ptr)) = (Elf_Addr) &r_debug; 1345 break; 1346 1347 case DT_MIPS_RLD_MAP_REL: 1348 // The MIPS_RLD_MAP_REL tag stores the offset to the .rld_map 1349 // section relative to the address of the tag itself. 1350 *((Elf_Addr *)(__DECONST(char*, dynp) + dynp->d_un.d_val)) = 1351 (Elf_Addr) &r_debug; 1352 break; 1353 1354 case DT_MIPS_PLTGOT: 1355 obj->mips_pltgot = (Elf_Addr *)(obj->relocbase + 1356 dynp->d_un.d_ptr); 1357 break; 1358 1359 #endif 1360 1361 #ifdef __powerpc__ 1362 #ifdef __powerpc64__ 1363 case DT_PPC64_GLINK: 1364 obj->glink = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1365 break; 1366 #else 1367 case DT_PPC_GOT: 1368 obj->gotptr = (Elf_Addr *)(obj->relocbase + dynp->d_un.d_ptr); 1369 break; 1370 #endif 1371 #endif 1372 1373 case DT_FLAGS_1: 1374 if (dynp->d_un.d_val & DF_1_NOOPEN) 1375 obj->z_noopen = true; 1376 if (dynp->d_un.d_val & DF_1_ORIGIN) 1377 obj->z_origin = true; 1378 if (dynp->d_un.d_val & DF_1_GLOBAL) 1379 obj->z_global = true; 1380 if (dynp->d_un.d_val & DF_1_BIND_NOW) 1381 obj->bind_now = true; 1382 if (dynp->d_un.d_val & DF_1_NODELETE) 1383 obj->z_nodelete = true; 1384 if (dynp->d_un.d_val & DF_1_LOADFLTR) 1385 obj->z_loadfltr = true; 1386 if (dynp->d_un.d_val & DF_1_INTERPOSE) 1387 obj->z_interpose = true; 1388 if (dynp->d_un.d_val & DF_1_NODEFLIB) 1389 obj->z_nodeflib = true; 1390 if (dynp->d_un.d_val & DF_1_PIE) 1391 obj->z_pie = true; 1392 break; 1393 1394 default: 1395 if (!early) { 1396 dbg("Ignoring d_tag %ld = %#lx", (long)dynp->d_tag, 1397 (long)dynp->d_tag); 1398 } 1399 break; 1400 } 1401 } 1402 1403 obj->traced = false; 1404 1405 if (plttype == DT_RELA) { 1406 obj->pltrela = (const Elf_Rela *) obj->pltrel; 1407 obj->pltrel = NULL; 1408 obj->pltrelasize = obj->pltrelsize; 1409 obj->pltrelsize = 0; 1410 } 1411 1412 /* Determine size of dynsym table (equal to nchains of sysv hash) */ 1413 if (obj->valid_hash_sysv) 1414 obj->dynsymcount = obj->nchains; 1415 else if (obj->valid_hash_gnu) { 1416 obj->dynsymcount = 0; 1417 for (bkt = 0; bkt < obj->nbuckets_gnu; bkt++) { 1418 if (obj->buckets_gnu[bkt] == 0) 1419 continue; 1420 hashval = &obj->chain_zero_gnu[obj->buckets_gnu[bkt]]; 1421 do 1422 obj->dynsymcount++; 1423 while ((*hashval++ & 1u) == 0); 1424 } 1425 obj->dynsymcount += obj->symndx_gnu; 1426 } 1427 1428 if (obj->linkmap.l_refname != NULL) 1429 obj->linkmap.l_refname = obj->strtab + (unsigned long)obj-> 1430 linkmap.l_refname; 1431 } 1432 1433 static bool 1434 obj_resolve_origin(Obj_Entry *obj) 1435 { 1436 1437 if (obj->origin_path != NULL) 1438 return (true); 1439 obj->origin_path = xmalloc(PATH_MAX); 1440 return (rtld_dirname_abs(obj->path, obj->origin_path) != -1); 1441 } 1442 1443 static bool 1444 digest_dynamic2(Obj_Entry *obj, const Elf_Dyn *dyn_rpath, 1445 const Elf_Dyn *dyn_soname, const Elf_Dyn *dyn_runpath) 1446 { 1447 1448 if (obj->z_origin && !obj_resolve_origin(obj)) 1449 return (false); 1450 1451 if (dyn_runpath != NULL) { 1452 obj->runpath = (const char *)obj->strtab + dyn_runpath->d_un.d_val; 1453 obj->runpath = origin_subst(obj, obj->runpath); 1454 } else if (dyn_rpath != NULL) { 1455 obj->rpath = (const char *)obj->strtab + dyn_rpath->d_un.d_val; 1456 obj->rpath = origin_subst(obj, obj->rpath); 1457 } 1458 if (dyn_soname != NULL) 1459 object_add_name(obj, obj->strtab + dyn_soname->d_un.d_val); 1460 return (true); 1461 } 1462 1463 static bool 1464 digest_dynamic(Obj_Entry *obj, int early) 1465 { 1466 const Elf_Dyn *dyn_rpath; 1467 const Elf_Dyn *dyn_soname; 1468 const Elf_Dyn *dyn_runpath; 1469 1470 digest_dynamic1(obj, early, &dyn_rpath, &dyn_soname, &dyn_runpath); 1471 return (digest_dynamic2(obj, dyn_rpath, dyn_soname, dyn_runpath)); 1472 } 1473 1474 /* 1475 * Process a shared object's program header. This is used only for the 1476 * main program, when the kernel has already loaded the main program 1477 * into memory before calling the dynamic linker. It creates and 1478 * returns an Obj_Entry structure. 1479 */ 1480 static Obj_Entry * 1481 digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path) 1482 { 1483 Obj_Entry *obj; 1484 const Elf_Phdr *phlimit = phdr + phnum; 1485 const Elf_Phdr *ph; 1486 Elf_Addr note_start, note_end; 1487 int nsegs = 0; 1488 1489 obj = obj_new(); 1490 for (ph = phdr; ph < phlimit; ph++) { 1491 if (ph->p_type != PT_PHDR) 1492 continue; 1493 1494 obj->phdr = phdr; 1495 obj->phsize = ph->p_memsz; 1496 obj->relocbase = __DECONST(char *, phdr) - ph->p_vaddr; 1497 break; 1498 } 1499 1500 obj->stack_flags = PF_X | PF_R | PF_W; 1501 1502 for (ph = phdr; ph < phlimit; ph++) { 1503 switch (ph->p_type) { 1504 1505 case PT_INTERP: 1506 obj->interp = (const char *)(ph->p_vaddr + obj->relocbase); 1507 break; 1508 1509 case PT_LOAD: 1510 if (nsegs == 0) { /* First load segment */ 1511 obj->vaddrbase = trunc_page(ph->p_vaddr); 1512 obj->mapbase = obj->vaddrbase + obj->relocbase; 1513 } else { /* Last load segment */ 1514 obj->mapsize = round_page(ph->p_vaddr + ph->p_memsz) - 1515 obj->vaddrbase; 1516 } 1517 nsegs++; 1518 break; 1519 1520 case PT_DYNAMIC: 1521 obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + obj->relocbase); 1522 break; 1523 1524 case PT_TLS: 1525 obj->tlsindex = 1; 1526 obj->tlssize = ph->p_memsz; 1527 obj->tlsalign = ph->p_align; 1528 obj->tlsinitsize = ph->p_filesz; 1529 obj->tlsinit = (void*)(ph->p_vaddr + obj->relocbase); 1530 obj->tlspoffset = ph->p_offset; 1531 break; 1532 1533 case PT_GNU_STACK: 1534 obj->stack_flags = ph->p_flags; 1535 break; 1536 1537 case PT_GNU_RELRO: 1538 obj->relro_page = obj->relocbase + trunc_page(ph->p_vaddr); 1539 obj->relro_size = round_page(ph->p_memsz); 1540 break; 1541 1542 case PT_NOTE: 1543 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; 1544 note_end = note_start + ph->p_filesz; 1545 digest_notes(obj, note_start, note_end); 1546 break; 1547 } 1548 } 1549 if (nsegs < 1) { 1550 _rtld_error("%s: too few PT_LOAD segments", path); 1551 return NULL; 1552 } 1553 1554 obj->entry = entry; 1555 return obj; 1556 } 1557 1558 void 1559 digest_notes(Obj_Entry *obj, Elf_Addr note_start, Elf_Addr note_end) 1560 { 1561 const Elf_Note *note; 1562 const char *note_name; 1563 uintptr_t p; 1564 1565 for (note = (const Elf_Note *)note_start; (Elf_Addr)note < note_end; 1566 note = (const Elf_Note *)((const char *)(note + 1) + 1567 roundup2(note->n_namesz, sizeof(Elf32_Addr)) + 1568 roundup2(note->n_descsz, sizeof(Elf32_Addr)))) { 1569 if (note->n_namesz != sizeof(NOTE_FREEBSD_VENDOR) || 1570 note->n_descsz != sizeof(int32_t)) 1571 continue; 1572 if (note->n_type != NT_FREEBSD_ABI_TAG && 1573 note->n_type != NT_FREEBSD_FEATURE_CTL && 1574 note->n_type != NT_FREEBSD_NOINIT_TAG) 1575 continue; 1576 note_name = (const char *)(note + 1); 1577 if (strncmp(NOTE_FREEBSD_VENDOR, note_name, 1578 sizeof(NOTE_FREEBSD_VENDOR)) != 0) 1579 continue; 1580 switch (note->n_type) { 1581 case NT_FREEBSD_ABI_TAG: 1582 /* FreeBSD osrel note */ 1583 p = (uintptr_t)(note + 1); 1584 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1585 obj->osrel = *(const int32_t *)(p); 1586 dbg("note osrel %d", obj->osrel); 1587 break; 1588 case NT_FREEBSD_FEATURE_CTL: 1589 /* FreeBSD ABI feature control note */ 1590 p = (uintptr_t)(note + 1); 1591 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1592 obj->fctl0 = *(const uint32_t *)(p); 1593 dbg("note fctl0 %#x", obj->fctl0); 1594 break; 1595 case NT_FREEBSD_NOINIT_TAG: 1596 /* FreeBSD 'crt does not call init' note */ 1597 obj->crt_no_init = true; 1598 dbg("note crt_no_init"); 1599 break; 1600 } 1601 } 1602 } 1603 1604 static Obj_Entry * 1605 dlcheck(void *handle) 1606 { 1607 Obj_Entry *obj; 1608 1609 TAILQ_FOREACH(obj, &obj_list, next) { 1610 if (obj == (Obj_Entry *) handle) 1611 break; 1612 } 1613 1614 if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) { 1615 _rtld_error("Invalid shared object handle %p", handle); 1616 return NULL; 1617 } 1618 return obj; 1619 } 1620 1621 /* 1622 * If the given object is already in the donelist, return true. Otherwise 1623 * add the object to the list and return false. 1624 */ 1625 static bool 1626 donelist_check(DoneList *dlp, const Obj_Entry *obj) 1627 { 1628 unsigned int i; 1629 1630 for (i = 0; i < dlp->num_used; i++) 1631 if (dlp->objs[i] == obj) 1632 return true; 1633 /* 1634 * Our donelist allocation should always be sufficient. But if 1635 * our threads locking isn't working properly, more shared objects 1636 * could have been loaded since we allocated the list. That should 1637 * never happen, but we'll handle it properly just in case it does. 1638 */ 1639 if (dlp->num_used < dlp->num_alloc) 1640 dlp->objs[dlp->num_used++] = obj; 1641 return false; 1642 } 1643 1644 /* 1645 * Hash function for symbol table lookup. Don't even think about changing 1646 * this. It is specified by the System V ABI. 1647 */ 1648 unsigned long 1649 elf_hash(const char *name) 1650 { 1651 const unsigned char *p = (const unsigned char *) name; 1652 unsigned long h = 0; 1653 unsigned long g; 1654 1655 while (*p != '\0') { 1656 h = (h << 4) + *p++; 1657 if ((g = h & 0xf0000000) != 0) 1658 h ^= g >> 24; 1659 h &= ~g; 1660 } 1661 return h; 1662 } 1663 1664 /* 1665 * The GNU hash function is the Daniel J. Bernstein hash clipped to 32 bits 1666 * unsigned in case it's implemented with a wider type. 1667 */ 1668 static uint32_t 1669 gnu_hash(const char *s) 1670 { 1671 uint32_t h; 1672 unsigned char c; 1673 1674 h = 5381; 1675 for (c = *s; c != '\0'; c = *++s) 1676 h = h * 33 + c; 1677 return (h & 0xffffffff); 1678 } 1679 1680 1681 /* 1682 * Find the library with the given name, and return its full pathname. 1683 * The returned string is dynamically allocated. Generates an error 1684 * message and returns NULL if the library cannot be found. 1685 * 1686 * If the second argument is non-NULL, then it refers to an already- 1687 * loaded shared object, whose library search path will be searched. 1688 * 1689 * If a library is successfully located via LD_LIBRARY_PATH_FDS, its 1690 * descriptor (which is close-on-exec) will be passed out via the third 1691 * argument. 1692 * 1693 * The search order is: 1694 * DT_RPATH in the referencing file _unless_ DT_RUNPATH is present (1) 1695 * DT_RPATH of the main object if DSO without defined DT_RUNPATH (1) 1696 * LD_LIBRARY_PATH 1697 * DT_RUNPATH in the referencing file 1698 * ldconfig hints (if -z nodefaultlib, filter out default library directories 1699 * from list) 1700 * /lib:/usr/lib _unless_ the referencing file is linked with -z nodefaultlib 1701 * 1702 * (1) Handled in digest_dynamic2 - rpath left NULL if runpath defined. 1703 */ 1704 static char * 1705 find_library(const char *xname, const Obj_Entry *refobj, int *fdp) 1706 { 1707 char *pathname, *refobj_path; 1708 const char *name; 1709 bool nodeflib, objgiven; 1710 1711 objgiven = refobj != NULL; 1712 1713 if (libmap_disable || !objgiven || 1714 (name = lm_find(refobj->path, xname)) == NULL) 1715 name = xname; 1716 1717 if (strchr(name, '/') != NULL) { /* Hard coded pathname */ 1718 if (name[0] != '/' && !trust) { 1719 _rtld_error("Absolute pathname required " 1720 "for shared object \"%s\"", name); 1721 return (NULL); 1722 } 1723 return (origin_subst(__DECONST(Obj_Entry *, refobj), 1724 __DECONST(char *, name))); 1725 } 1726 1727 dbg(" Searching for \"%s\"", name); 1728 refobj_path = objgiven ? refobj->path : NULL; 1729 1730 /* 1731 * If refobj->rpath != NULL, then refobj->runpath is NULL. Fall 1732 * back to pre-conforming behaviour if user requested so with 1733 * LD_LIBRARY_PATH_RPATH environment variable and ignore -z 1734 * nodeflib. 1735 */ 1736 if (objgiven && refobj->rpath != NULL && ld_library_path_rpath) { 1737 pathname = search_library_path(name, ld_library_path, 1738 refobj_path, fdp); 1739 if (pathname != NULL) 1740 return (pathname); 1741 if (refobj != NULL) { 1742 pathname = search_library_path(name, refobj->rpath, 1743 refobj_path, fdp); 1744 if (pathname != NULL) 1745 return (pathname); 1746 } 1747 pathname = search_library_pathfds(name, ld_library_dirs, fdp); 1748 if (pathname != NULL) 1749 return (pathname); 1750 pathname = search_library_path(name, gethints(false), 1751 refobj_path, fdp); 1752 if (pathname != NULL) 1753 return (pathname); 1754 pathname = search_library_path(name, ld_standard_library_path, 1755 refobj_path, fdp); 1756 if (pathname != NULL) 1757 return (pathname); 1758 } else { 1759 nodeflib = objgiven ? refobj->z_nodeflib : false; 1760 if (objgiven) { 1761 pathname = search_library_path(name, refobj->rpath, 1762 refobj->path, fdp); 1763 if (pathname != NULL) 1764 return (pathname); 1765 } 1766 if (objgiven && refobj->runpath == NULL && refobj != obj_main) { 1767 pathname = search_library_path(name, obj_main->rpath, 1768 refobj_path, fdp); 1769 if (pathname != NULL) 1770 return (pathname); 1771 } 1772 pathname = search_library_path(name, ld_library_path, 1773 refobj_path, fdp); 1774 if (pathname != NULL) 1775 return (pathname); 1776 if (objgiven) { 1777 pathname = search_library_path(name, refobj->runpath, 1778 refobj_path, fdp); 1779 if (pathname != NULL) 1780 return (pathname); 1781 } 1782 pathname = search_library_pathfds(name, ld_library_dirs, fdp); 1783 if (pathname != NULL) 1784 return (pathname); 1785 pathname = search_library_path(name, gethints(nodeflib), 1786 refobj_path, fdp); 1787 if (pathname != NULL) 1788 return (pathname); 1789 if (objgiven && !nodeflib) { 1790 pathname = search_library_path(name, 1791 ld_standard_library_path, refobj_path, fdp); 1792 if (pathname != NULL) 1793 return (pathname); 1794 } 1795 } 1796 1797 if (objgiven && refobj->path != NULL) { 1798 _rtld_error("Shared object \"%s\" not found, " 1799 "required by \"%s\"", name, basename(refobj->path)); 1800 } else { 1801 _rtld_error("Shared object \"%s\" not found", name); 1802 } 1803 return (NULL); 1804 } 1805 1806 /* 1807 * Given a symbol number in a referencing object, find the corresponding 1808 * definition of the symbol. Returns a pointer to the symbol, or NULL if 1809 * no definition was found. Returns a pointer to the Obj_Entry of the 1810 * defining object via the reference parameter DEFOBJ_OUT. 1811 */ 1812 const Elf_Sym * 1813 find_symdef(unsigned long symnum, const Obj_Entry *refobj, 1814 const Obj_Entry **defobj_out, int flags, SymCache *cache, 1815 RtldLockState *lockstate) 1816 { 1817 const Elf_Sym *ref; 1818 const Elf_Sym *def; 1819 const Obj_Entry *defobj; 1820 const Ver_Entry *ve; 1821 SymLook req; 1822 const char *name; 1823 int res; 1824 1825 /* 1826 * If we have already found this symbol, get the information from 1827 * the cache. 1828 */ 1829 if (symnum >= refobj->dynsymcount) 1830 return NULL; /* Bad object */ 1831 if (cache != NULL && cache[symnum].sym != NULL) { 1832 *defobj_out = cache[symnum].obj; 1833 return cache[symnum].sym; 1834 } 1835 1836 ref = refobj->symtab + symnum; 1837 name = refobj->strtab + ref->st_name; 1838 def = NULL; 1839 defobj = NULL; 1840 ve = NULL; 1841 1842 /* 1843 * We don't have to do a full scale lookup if the symbol is local. 1844 * We know it will bind to the instance in this load module; to 1845 * which we already have a pointer (ie ref). By not doing a lookup, 1846 * we not only improve performance, but it also avoids unresolvable 1847 * symbols when local symbols are not in the hash table. This has 1848 * been seen with the ia64 toolchain. 1849 */ 1850 if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) { 1851 if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) { 1852 _rtld_error("%s: Bogus symbol table entry %lu", refobj->path, 1853 symnum); 1854 } 1855 symlook_init(&req, name); 1856 req.flags = flags; 1857 ve = req.ventry = fetch_ventry(refobj, symnum); 1858 req.lockstate = lockstate; 1859 res = symlook_default(&req, refobj); 1860 if (res == 0) { 1861 def = req.sym_out; 1862 defobj = req.defobj_out; 1863 } 1864 } else { 1865 def = ref; 1866 defobj = refobj; 1867 } 1868 1869 /* 1870 * If we found no definition and the reference is weak, treat the 1871 * symbol as having the value zero. 1872 */ 1873 if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) { 1874 def = &sym_zero; 1875 defobj = obj_main; 1876 } 1877 1878 if (def != NULL) { 1879 *defobj_out = defobj; 1880 /* Record the information in the cache to avoid subsequent lookups. */ 1881 if (cache != NULL) { 1882 cache[symnum].sym = def; 1883 cache[symnum].obj = defobj; 1884 } 1885 } else { 1886 if (refobj != &obj_rtld) 1887 _rtld_error("%s: Undefined symbol \"%s%s%s\"", refobj->path, name, 1888 ve != NULL ? "@" : "", ve != NULL ? ve->name : ""); 1889 } 1890 return def; 1891 } 1892 1893 /* 1894 * Return the search path from the ldconfig hints file, reading it if 1895 * necessary. If nostdlib is true, then the default search paths are 1896 * not added to result. 1897 * 1898 * Returns NULL if there are problems with the hints file, 1899 * or if the search path there is empty. 1900 */ 1901 static const char * 1902 gethints(bool nostdlib) 1903 { 1904 static char *filtered_path; 1905 static const char *hints; 1906 static struct elfhints_hdr hdr; 1907 struct fill_search_info_args sargs, hargs; 1908 struct dl_serinfo smeta, hmeta, *SLPinfo, *hintinfo; 1909 struct dl_serpath *SLPpath, *hintpath; 1910 char *p; 1911 struct stat hint_stat; 1912 unsigned int SLPndx, hintndx, fndx, fcount; 1913 int fd; 1914 size_t flen; 1915 uint32_t dl; 1916 bool skip; 1917 1918 /* First call, read the hints file */ 1919 if (hints == NULL) { 1920 /* Keep from trying again in case the hints file is bad. */ 1921 hints = ""; 1922 1923 if ((fd = open(ld_elf_hints_path, O_RDONLY | O_CLOEXEC)) == -1) 1924 return (NULL); 1925 1926 /* 1927 * Check of hdr.dirlistlen value against type limit 1928 * intends to pacify static analyzers. Further 1929 * paranoia leads to checks that dirlist is fully 1930 * contained in the file range. 1931 */ 1932 if (read(fd, &hdr, sizeof hdr) != sizeof hdr || 1933 hdr.magic != ELFHINTS_MAGIC || 1934 hdr.version != 1 || hdr.dirlistlen > UINT_MAX / 2 || 1935 fstat(fd, &hint_stat) == -1) { 1936 cleanup1: 1937 close(fd); 1938 hdr.dirlistlen = 0; 1939 return (NULL); 1940 } 1941 dl = hdr.strtab; 1942 if (dl + hdr.dirlist < dl) 1943 goto cleanup1; 1944 dl += hdr.dirlist; 1945 if (dl + hdr.dirlistlen < dl) 1946 goto cleanup1; 1947 dl += hdr.dirlistlen; 1948 if (dl > hint_stat.st_size) 1949 goto cleanup1; 1950 p = xmalloc(hdr.dirlistlen + 1); 1951 if (pread(fd, p, hdr.dirlistlen + 1, 1952 hdr.strtab + hdr.dirlist) != (ssize_t)hdr.dirlistlen + 1 || 1953 p[hdr.dirlistlen] != '\0') { 1954 free(p); 1955 goto cleanup1; 1956 } 1957 hints = p; 1958 close(fd); 1959 } 1960 1961 /* 1962 * If caller agreed to receive list which includes the default 1963 * paths, we are done. Otherwise, if we still did not 1964 * calculated filtered result, do it now. 1965 */ 1966 if (!nostdlib) 1967 return (hints[0] != '\0' ? hints : NULL); 1968 if (filtered_path != NULL) 1969 goto filt_ret; 1970 1971 /* 1972 * Obtain the list of all configured search paths, and the 1973 * list of the default paths. 1974 * 1975 * First estimate the size of the results. 1976 */ 1977 smeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 1978 smeta.dls_cnt = 0; 1979 hmeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 1980 hmeta.dls_cnt = 0; 1981 1982 sargs.request = RTLD_DI_SERINFOSIZE; 1983 sargs.serinfo = &smeta; 1984 hargs.request = RTLD_DI_SERINFOSIZE; 1985 hargs.serinfo = &hmeta; 1986 1987 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 1988 &sargs); 1989 path_enumerate(hints, fill_search_info, NULL, &hargs); 1990 1991 SLPinfo = xmalloc(smeta.dls_size); 1992 hintinfo = xmalloc(hmeta.dls_size); 1993 1994 /* 1995 * Next fetch both sets of paths. 1996 */ 1997 sargs.request = RTLD_DI_SERINFO; 1998 sargs.serinfo = SLPinfo; 1999 sargs.serpath = &SLPinfo->dls_serpath[0]; 2000 sargs.strspace = (char *)&SLPinfo->dls_serpath[smeta.dls_cnt]; 2001 2002 hargs.request = RTLD_DI_SERINFO; 2003 hargs.serinfo = hintinfo; 2004 hargs.serpath = &hintinfo->dls_serpath[0]; 2005 hargs.strspace = (char *)&hintinfo->dls_serpath[hmeta.dls_cnt]; 2006 2007 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 2008 &sargs); 2009 path_enumerate(hints, fill_search_info, NULL, &hargs); 2010 2011 /* 2012 * Now calculate the difference between two sets, by excluding 2013 * standard paths from the full set. 2014 */ 2015 fndx = 0; 2016 fcount = 0; 2017 filtered_path = xmalloc(hdr.dirlistlen + 1); 2018 hintpath = &hintinfo->dls_serpath[0]; 2019 for (hintndx = 0; hintndx < hmeta.dls_cnt; hintndx++, hintpath++) { 2020 skip = false; 2021 SLPpath = &SLPinfo->dls_serpath[0]; 2022 /* 2023 * Check each standard path against current. 2024 */ 2025 for (SLPndx = 0; SLPndx < smeta.dls_cnt; SLPndx++, SLPpath++) { 2026 /* matched, skip the path */ 2027 if (!strcmp(hintpath->dls_name, SLPpath->dls_name)) { 2028 skip = true; 2029 break; 2030 } 2031 } 2032 if (skip) 2033 continue; 2034 /* 2035 * Not matched against any standard path, add the path 2036 * to result. Separate consequtive paths with ':'. 2037 */ 2038 if (fcount > 0) { 2039 filtered_path[fndx] = ':'; 2040 fndx++; 2041 } 2042 fcount++; 2043 flen = strlen(hintpath->dls_name); 2044 strncpy((filtered_path + fndx), hintpath->dls_name, flen); 2045 fndx += flen; 2046 } 2047 filtered_path[fndx] = '\0'; 2048 2049 free(SLPinfo); 2050 free(hintinfo); 2051 2052 filt_ret: 2053 return (filtered_path[0] != '\0' ? filtered_path : NULL); 2054 } 2055 2056 static void 2057 init_dag(Obj_Entry *root) 2058 { 2059 const Needed_Entry *needed; 2060 const Objlist_Entry *elm; 2061 DoneList donelist; 2062 2063 if (root->dag_inited) 2064 return; 2065 donelist_init(&donelist); 2066 2067 /* Root object belongs to own DAG. */ 2068 objlist_push_tail(&root->dldags, root); 2069 objlist_push_tail(&root->dagmembers, root); 2070 donelist_check(&donelist, root); 2071 2072 /* 2073 * Add dependencies of root object to DAG in breadth order 2074 * by exploiting the fact that each new object get added 2075 * to the tail of the dagmembers list. 2076 */ 2077 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2078 for (needed = elm->obj->needed; needed != NULL; needed = needed->next) { 2079 if (needed->obj == NULL || donelist_check(&donelist, needed->obj)) 2080 continue; 2081 objlist_push_tail(&needed->obj->dldags, root); 2082 objlist_push_tail(&root->dagmembers, needed->obj); 2083 } 2084 } 2085 root->dag_inited = true; 2086 } 2087 2088 static void 2089 init_marker(Obj_Entry *marker) 2090 { 2091 2092 bzero(marker, sizeof(*marker)); 2093 marker->marker = true; 2094 } 2095 2096 Obj_Entry * 2097 globallist_curr(const Obj_Entry *obj) 2098 { 2099 2100 for (;;) { 2101 if (obj == NULL) 2102 return (NULL); 2103 if (!obj->marker) 2104 return (__DECONST(Obj_Entry *, obj)); 2105 obj = TAILQ_PREV(obj, obj_entry_q, next); 2106 } 2107 } 2108 2109 Obj_Entry * 2110 globallist_next(const Obj_Entry *obj) 2111 { 2112 2113 for (;;) { 2114 obj = TAILQ_NEXT(obj, next); 2115 if (obj == NULL) 2116 return (NULL); 2117 if (!obj->marker) 2118 return (__DECONST(Obj_Entry *, obj)); 2119 } 2120 } 2121 2122 /* Prevent the object from being unmapped while the bind lock is dropped. */ 2123 static void 2124 hold_object(Obj_Entry *obj) 2125 { 2126 2127 obj->holdcount++; 2128 } 2129 2130 static void 2131 unhold_object(Obj_Entry *obj) 2132 { 2133 2134 assert(obj->holdcount > 0); 2135 if (--obj->holdcount == 0 && obj->unholdfree) 2136 release_object(obj); 2137 } 2138 2139 static void 2140 process_z(Obj_Entry *root) 2141 { 2142 const Objlist_Entry *elm; 2143 Obj_Entry *obj; 2144 2145 /* 2146 * Walk over object DAG and process every dependent object 2147 * that is marked as DF_1_NODELETE or DF_1_GLOBAL. They need 2148 * to grow their own DAG. 2149 * 2150 * For DF_1_GLOBAL, DAG is required for symbol lookups in 2151 * symlook_global() to work. 2152 * 2153 * For DF_1_NODELETE, the DAG should have its reference upped. 2154 */ 2155 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2156 obj = elm->obj; 2157 if (obj == NULL) 2158 continue; 2159 if (obj->z_nodelete && !obj->ref_nodel) { 2160 dbg("obj %s -z nodelete", obj->path); 2161 init_dag(obj); 2162 ref_dag(obj); 2163 obj->ref_nodel = true; 2164 } 2165 if (obj->z_global && objlist_find(&list_global, obj) == NULL) { 2166 dbg("obj %s -z global", obj->path); 2167 objlist_push_tail(&list_global, obj); 2168 init_dag(obj); 2169 } 2170 } 2171 } 2172 2173 static void 2174 parse_rtld_phdr(Obj_Entry *obj) 2175 { 2176 const Elf_Phdr *ph; 2177 Elf_Addr note_start, note_end; 2178 2179 obj->stack_flags = PF_X | PF_R | PF_W; 2180 for (ph = obj->phdr; (const char *)ph < (const char *)obj->phdr + 2181 obj->phsize; ph++) { 2182 switch (ph->p_type) { 2183 case PT_GNU_STACK: 2184 obj->stack_flags = ph->p_flags; 2185 break; 2186 case PT_GNU_RELRO: 2187 obj->relro_page = obj->relocbase + 2188 trunc_page(ph->p_vaddr); 2189 obj->relro_size = round_page(ph->p_memsz); 2190 break; 2191 case PT_NOTE: 2192 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; 2193 note_end = note_start + ph->p_filesz; 2194 digest_notes(obj, note_start, note_end); 2195 break; 2196 } 2197 } 2198 } 2199 2200 /* 2201 * Initialize the dynamic linker. The argument is the address at which 2202 * the dynamic linker has been mapped into memory. The primary task of 2203 * this function is to relocate the dynamic linker. 2204 */ 2205 static void 2206 init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info) 2207 { 2208 Obj_Entry objtmp; /* Temporary rtld object */ 2209 const Elf_Ehdr *ehdr; 2210 const Elf_Dyn *dyn_rpath; 2211 const Elf_Dyn *dyn_soname; 2212 const Elf_Dyn *dyn_runpath; 2213 2214 #ifdef RTLD_INIT_PAGESIZES_EARLY 2215 /* The page size is required by the dynamic memory allocator. */ 2216 init_pagesizes(aux_info); 2217 #endif 2218 2219 /* 2220 * Conjure up an Obj_Entry structure for the dynamic linker. 2221 * 2222 * The "path" member can't be initialized yet because string constants 2223 * cannot yet be accessed. Below we will set it correctly. 2224 */ 2225 memset(&objtmp, 0, sizeof(objtmp)); 2226 objtmp.path = NULL; 2227 objtmp.rtld = true; 2228 objtmp.mapbase = mapbase; 2229 #ifdef PIC 2230 objtmp.relocbase = mapbase; 2231 #endif 2232 2233 objtmp.dynamic = rtld_dynamic(&objtmp); 2234 digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname, &dyn_runpath); 2235 assert(objtmp.needed == NULL); 2236 #if !defined(__mips__) 2237 /* MIPS has a bogus DT_TEXTREL. */ 2238 assert(!objtmp.textrel); 2239 #endif 2240 /* 2241 * Temporarily put the dynamic linker entry into the object list, so 2242 * that symbols can be found. 2243 */ 2244 relocate_objects(&objtmp, true, &objtmp, 0, NULL); 2245 2246 ehdr = (Elf_Ehdr *)mapbase; 2247 objtmp.phdr = (Elf_Phdr *)((char *)mapbase + ehdr->e_phoff); 2248 objtmp.phsize = ehdr->e_phnum * sizeof(objtmp.phdr[0]); 2249 2250 /* Initialize the object list. */ 2251 TAILQ_INIT(&obj_list); 2252 2253 /* Now that non-local variables can be accesses, copy out obj_rtld. */ 2254 memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld)); 2255 2256 #ifndef RTLD_INIT_PAGESIZES_EARLY 2257 /* The page size is required by the dynamic memory allocator. */ 2258 init_pagesizes(aux_info); 2259 #endif 2260 2261 if (aux_info[AT_OSRELDATE] != NULL) 2262 osreldate = aux_info[AT_OSRELDATE]->a_un.a_val; 2263 2264 digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname, dyn_runpath); 2265 2266 /* Replace the path with a dynamically allocated copy. */ 2267 obj_rtld.path = xstrdup(ld_path_rtld); 2268 2269 parse_rtld_phdr(&obj_rtld); 2270 obj_enforce_relro(&obj_rtld); 2271 2272 r_debug.r_version = R_DEBUG_VERSION; 2273 r_debug.r_brk = r_debug_state; 2274 r_debug.r_state = RT_CONSISTENT; 2275 r_debug.r_ldbase = obj_rtld.relocbase; 2276 } 2277 2278 /* 2279 * Retrieve the array of supported page sizes. The kernel provides the page 2280 * sizes in increasing order. 2281 */ 2282 static void 2283 init_pagesizes(Elf_Auxinfo **aux_info) 2284 { 2285 static size_t psa[MAXPAGESIZES]; 2286 int mib[2]; 2287 size_t len, size; 2288 2289 if (aux_info[AT_PAGESIZES] != NULL && aux_info[AT_PAGESIZESLEN] != 2290 NULL) { 2291 size = aux_info[AT_PAGESIZESLEN]->a_un.a_val; 2292 pagesizes = aux_info[AT_PAGESIZES]->a_un.a_ptr; 2293 } else { 2294 len = 2; 2295 if (sysctlnametomib("hw.pagesizes", mib, &len) == 0) 2296 size = sizeof(psa); 2297 else { 2298 /* As a fallback, retrieve the base page size. */ 2299 size = sizeof(psa[0]); 2300 if (aux_info[AT_PAGESZ] != NULL) { 2301 psa[0] = aux_info[AT_PAGESZ]->a_un.a_val; 2302 goto psa_filled; 2303 } else { 2304 mib[0] = CTL_HW; 2305 mib[1] = HW_PAGESIZE; 2306 len = 2; 2307 } 2308 } 2309 if (sysctl(mib, len, psa, &size, NULL, 0) == -1) { 2310 _rtld_error("sysctl for hw.pagesize(s) failed"); 2311 rtld_die(); 2312 } 2313 psa_filled: 2314 pagesizes = psa; 2315 } 2316 npagesizes = size / sizeof(pagesizes[0]); 2317 /* Discard any invalid entries at the end of the array. */ 2318 while (npagesizes > 0 && pagesizes[npagesizes - 1] == 0) 2319 npagesizes--; 2320 } 2321 2322 /* 2323 * Add the init functions from a needed object list (and its recursive 2324 * needed objects) to "list". This is not used directly; it is a helper 2325 * function for initlist_add_objects(). The write lock must be held 2326 * when this function is called. 2327 */ 2328 static void 2329 initlist_add_neededs(Needed_Entry *needed, Objlist *list) 2330 { 2331 /* Recursively process the successor needed objects. */ 2332 if (needed->next != NULL) 2333 initlist_add_neededs(needed->next, list); 2334 2335 /* Process the current needed object. */ 2336 if (needed->obj != NULL) 2337 initlist_add_objects(needed->obj, needed->obj, list); 2338 } 2339 2340 /* 2341 * Scan all of the DAGs rooted in the range of objects from "obj" to 2342 * "tail" and add their init functions to "list". This recurses over 2343 * the DAGs and ensure the proper init ordering such that each object's 2344 * needed libraries are initialized before the object itself. At the 2345 * same time, this function adds the objects to the global finalization 2346 * list "list_fini" in the opposite order. The write lock must be 2347 * held when this function is called. 2348 */ 2349 static void 2350 initlist_add_objects(Obj_Entry *obj, Obj_Entry *tail, Objlist *list) 2351 { 2352 Obj_Entry *nobj; 2353 2354 if (obj->init_scanned || obj->init_done) 2355 return; 2356 obj->init_scanned = true; 2357 2358 /* Recursively process the successor objects. */ 2359 nobj = globallist_next(obj); 2360 if (nobj != NULL && obj != tail) 2361 initlist_add_objects(nobj, tail, list); 2362 2363 /* Recursively process the needed objects. */ 2364 if (obj->needed != NULL) 2365 initlist_add_neededs(obj->needed, list); 2366 if (obj->needed_filtees != NULL) 2367 initlist_add_neededs(obj->needed_filtees, list); 2368 if (obj->needed_aux_filtees != NULL) 2369 initlist_add_neededs(obj->needed_aux_filtees, list); 2370 2371 /* Add the object to the init list. */ 2372 objlist_push_tail(list, obj); 2373 2374 /* Add the object to the global fini list in the reverse order. */ 2375 if ((obj->fini != (Elf_Addr)NULL || obj->fini_array != (Elf_Addr)NULL) 2376 && !obj->on_fini_list) { 2377 objlist_push_head(&list_fini, obj); 2378 obj->on_fini_list = true; 2379 } 2380 } 2381 2382 #ifndef FPTR_TARGET 2383 #define FPTR_TARGET(f) ((Elf_Addr) (f)) 2384 #endif 2385 2386 static void 2387 free_needed_filtees(Needed_Entry *n, RtldLockState *lockstate) 2388 { 2389 Needed_Entry *needed, *needed1; 2390 2391 for (needed = n; needed != NULL; needed = needed->next) { 2392 if (needed->obj != NULL) { 2393 dlclose_locked(needed->obj, lockstate); 2394 needed->obj = NULL; 2395 } 2396 } 2397 for (needed = n; needed != NULL; needed = needed1) { 2398 needed1 = needed->next; 2399 free(needed); 2400 } 2401 } 2402 2403 static void 2404 unload_filtees(Obj_Entry *obj, RtldLockState *lockstate) 2405 { 2406 2407 free_needed_filtees(obj->needed_filtees, lockstate); 2408 obj->needed_filtees = NULL; 2409 free_needed_filtees(obj->needed_aux_filtees, lockstate); 2410 obj->needed_aux_filtees = NULL; 2411 obj->filtees_loaded = false; 2412 } 2413 2414 static void 2415 load_filtee1(Obj_Entry *obj, Needed_Entry *needed, int flags, 2416 RtldLockState *lockstate) 2417 { 2418 2419 for (; needed != NULL; needed = needed->next) { 2420 needed->obj = dlopen_object(obj->strtab + needed->name, -1, obj, 2421 flags, ((ld_loadfltr || obj->z_loadfltr) ? RTLD_NOW : RTLD_LAZY) | 2422 RTLD_LOCAL, lockstate); 2423 } 2424 } 2425 2426 static void 2427 load_filtees(Obj_Entry *obj, int flags, RtldLockState *lockstate) 2428 { 2429 2430 lock_restart_for_upgrade(lockstate); 2431 if (!obj->filtees_loaded) { 2432 load_filtee1(obj, obj->needed_filtees, flags, lockstate); 2433 load_filtee1(obj, obj->needed_aux_filtees, flags, lockstate); 2434 obj->filtees_loaded = true; 2435 } 2436 } 2437 2438 static int 2439 process_needed(Obj_Entry *obj, Needed_Entry *needed, int flags) 2440 { 2441 Obj_Entry *obj1; 2442 2443 for (; needed != NULL; needed = needed->next) { 2444 obj1 = needed->obj = load_object(obj->strtab + needed->name, -1, obj, 2445 flags & ~RTLD_LO_NOLOAD); 2446 if (obj1 == NULL && !ld_tracing && (flags & RTLD_LO_FILTEES) == 0) 2447 return (-1); 2448 } 2449 return (0); 2450 } 2451 2452 /* 2453 * Given a shared object, traverse its list of needed objects, and load 2454 * each of them. Returns 0 on success. Generates an error message and 2455 * returns -1 on failure. 2456 */ 2457 static int 2458 load_needed_objects(Obj_Entry *first, int flags) 2459 { 2460 Obj_Entry *obj; 2461 2462 for (obj = first; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 2463 if (obj->marker) 2464 continue; 2465 if (process_needed(obj, obj->needed, flags) == -1) 2466 return (-1); 2467 } 2468 return (0); 2469 } 2470 2471 static int 2472 load_preload_objects(void) 2473 { 2474 char *p = ld_preload; 2475 Obj_Entry *obj; 2476 static const char delim[] = " \t:;"; 2477 2478 if (p == NULL) 2479 return 0; 2480 2481 p += strspn(p, delim); 2482 while (*p != '\0') { 2483 size_t len = strcspn(p, delim); 2484 char savech; 2485 2486 savech = p[len]; 2487 p[len] = '\0'; 2488 obj = load_object(p, -1, NULL, 0); 2489 if (obj == NULL) 2490 return -1; /* XXX - cleanup */ 2491 obj->z_interpose = true; 2492 p[len] = savech; 2493 p += len; 2494 p += strspn(p, delim); 2495 } 2496 LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL); 2497 return 0; 2498 } 2499 2500 static const char * 2501 printable_path(const char *path) 2502 { 2503 2504 return (path == NULL ? "<unknown>" : path); 2505 } 2506 2507 /* 2508 * Load a shared object into memory, if it is not already loaded. The 2509 * object may be specified by name or by user-supplied file descriptor 2510 * fd_u. In the later case, the fd_u descriptor is not closed, but its 2511 * duplicate is. 2512 * 2513 * Returns a pointer to the Obj_Entry for the object. Returns NULL 2514 * on failure. 2515 */ 2516 static Obj_Entry * 2517 load_object(const char *name, int fd_u, const Obj_Entry *refobj, int flags) 2518 { 2519 Obj_Entry *obj; 2520 int fd; 2521 struct stat sb; 2522 char *path; 2523 2524 fd = -1; 2525 if (name != NULL) { 2526 TAILQ_FOREACH(obj, &obj_list, next) { 2527 if (obj->marker || obj->doomed) 2528 continue; 2529 if (object_match_name(obj, name)) 2530 return (obj); 2531 } 2532 2533 path = find_library(name, refobj, &fd); 2534 if (path == NULL) 2535 return (NULL); 2536 } else 2537 path = NULL; 2538 2539 if (fd >= 0) { 2540 /* 2541 * search_library_pathfds() opens a fresh file descriptor for the 2542 * library, so there is no need to dup(). 2543 */ 2544 } else if (fd_u == -1) { 2545 /* 2546 * If we didn't find a match by pathname, or the name is not 2547 * supplied, open the file and check again by device and inode. 2548 * This avoids false mismatches caused by multiple links or ".." 2549 * in pathnames. 2550 * 2551 * To avoid a race, we open the file and use fstat() rather than 2552 * using stat(). 2553 */ 2554 if ((fd = open(path, O_RDONLY | O_CLOEXEC | O_VERIFY)) == -1) { 2555 _rtld_error("Cannot open \"%s\"", path); 2556 free(path); 2557 return (NULL); 2558 } 2559 } else { 2560 fd = fcntl(fd_u, F_DUPFD_CLOEXEC, 0); 2561 if (fd == -1) { 2562 _rtld_error("Cannot dup fd"); 2563 free(path); 2564 return (NULL); 2565 } 2566 } 2567 if (fstat(fd, &sb) == -1) { 2568 _rtld_error("Cannot fstat \"%s\"", printable_path(path)); 2569 close(fd); 2570 free(path); 2571 return NULL; 2572 } 2573 TAILQ_FOREACH(obj, &obj_list, next) { 2574 if (obj->marker || obj->doomed) 2575 continue; 2576 if (obj->ino == sb.st_ino && obj->dev == sb.st_dev) 2577 break; 2578 } 2579 if (obj != NULL && name != NULL) { 2580 object_add_name(obj, name); 2581 free(path); 2582 close(fd); 2583 return obj; 2584 } 2585 if (flags & RTLD_LO_NOLOAD) { 2586 free(path); 2587 close(fd); 2588 return (NULL); 2589 } 2590 2591 /* First use of this object, so we must map it in */ 2592 obj = do_load_object(fd, name, path, &sb, flags); 2593 if (obj == NULL) 2594 free(path); 2595 close(fd); 2596 2597 return obj; 2598 } 2599 2600 static Obj_Entry * 2601 do_load_object(int fd, const char *name, char *path, struct stat *sbp, 2602 int flags) 2603 { 2604 Obj_Entry *obj; 2605 struct statfs fs; 2606 2607 /* 2608 * but first, make sure that environment variables haven't been 2609 * used to circumvent the noexec flag on a filesystem. 2610 */ 2611 if (dangerous_ld_env) { 2612 if (fstatfs(fd, &fs) != 0) { 2613 _rtld_error("Cannot fstatfs \"%s\"", printable_path(path)); 2614 return NULL; 2615 } 2616 if (fs.f_flags & MNT_NOEXEC) { 2617 _rtld_error("Cannot execute objects on %s", fs.f_mntonname); 2618 return NULL; 2619 } 2620 } 2621 dbg("loading \"%s\"", printable_path(path)); 2622 obj = map_object(fd, printable_path(path), sbp); 2623 if (obj == NULL) 2624 return NULL; 2625 2626 /* 2627 * If DT_SONAME is present in the object, digest_dynamic2 already 2628 * added it to the object names. 2629 */ 2630 if (name != NULL) 2631 object_add_name(obj, name); 2632 obj->path = path; 2633 if (!digest_dynamic(obj, 0)) 2634 goto errp; 2635 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", obj->path, 2636 obj->valid_hash_sysv, obj->valid_hash_gnu, obj->dynsymcount); 2637 if (obj->z_pie && (flags & RTLD_LO_TRACE) == 0) { 2638 dbg("refusing to load PIE executable \"%s\"", obj->path); 2639 _rtld_error("Cannot load PIE binary %s as DSO", obj->path); 2640 goto errp; 2641 } 2642 if (obj->z_noopen && (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) == 2643 RTLD_LO_DLOPEN) { 2644 dbg("refusing to load non-loadable \"%s\"", obj->path); 2645 _rtld_error("Cannot dlopen non-loadable %s", obj->path); 2646 goto errp; 2647 } 2648 2649 obj->dlopened = (flags & RTLD_LO_DLOPEN) != 0; 2650 TAILQ_INSERT_TAIL(&obj_list, obj, next); 2651 obj_count++; 2652 obj_loads++; 2653 linkmap_add(obj); /* for GDB & dlinfo() */ 2654 max_stack_flags |= obj->stack_flags; 2655 2656 dbg(" %p .. %p: %s", obj->mapbase, 2657 obj->mapbase + obj->mapsize - 1, obj->path); 2658 if (obj->textrel) 2659 dbg(" WARNING: %s has impure text", obj->path); 2660 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 2661 obj->path); 2662 2663 return (obj); 2664 2665 errp: 2666 munmap(obj->mapbase, obj->mapsize); 2667 obj_free(obj); 2668 return (NULL); 2669 } 2670 2671 Obj_Entry * 2672 obj_from_addr(const void *addr) 2673 { 2674 Obj_Entry *obj; 2675 2676 TAILQ_FOREACH(obj, &obj_list, next) { 2677 if (obj->marker) 2678 continue; 2679 if (addr < (void *) obj->mapbase) 2680 continue; 2681 if (addr < (void *)(obj->mapbase + obj->mapsize)) 2682 return obj; 2683 } 2684 return NULL; 2685 } 2686 2687 static void 2688 preinit_main(void) 2689 { 2690 Elf_Addr *preinit_addr; 2691 int index; 2692 2693 preinit_addr = (Elf_Addr *)obj_main->preinit_array; 2694 if (preinit_addr == NULL) 2695 return; 2696 2697 for (index = 0; index < obj_main->preinit_array_num; index++) { 2698 if (preinit_addr[index] != 0 && preinit_addr[index] != 1) { 2699 dbg("calling preinit function for %s at %p", obj_main->path, 2700 (void *)preinit_addr[index]); 2701 LD_UTRACE(UTRACE_INIT_CALL, obj_main, (void *)preinit_addr[index], 2702 0, 0, obj_main->path); 2703 call_init_pointer(obj_main, preinit_addr[index]); 2704 } 2705 } 2706 } 2707 2708 /* 2709 * Call the finalization functions for each of the objects in "list" 2710 * belonging to the DAG of "root" and referenced once. If NULL "root" 2711 * is specified, every finalization function will be called regardless 2712 * of the reference count and the list elements won't be freed. All of 2713 * the objects are expected to have non-NULL fini functions. 2714 */ 2715 static void 2716 objlist_call_fini(Objlist *list, Obj_Entry *root, RtldLockState *lockstate) 2717 { 2718 Objlist_Entry *elm; 2719 char *saved_msg; 2720 Elf_Addr *fini_addr; 2721 int index; 2722 2723 assert(root == NULL || root->refcount == 1); 2724 2725 if (root != NULL) 2726 root->doomed = true; 2727 2728 /* 2729 * Preserve the current error message since a fini function might 2730 * call into the dynamic linker and overwrite it. 2731 */ 2732 saved_msg = errmsg_save(); 2733 do { 2734 STAILQ_FOREACH(elm, list, link) { 2735 if (root != NULL && (elm->obj->refcount != 1 || 2736 objlist_find(&root->dagmembers, elm->obj) == NULL)) 2737 continue; 2738 /* Remove object from fini list to prevent recursive invocation. */ 2739 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 2740 /* Ensure that new references cannot be acquired. */ 2741 elm->obj->doomed = true; 2742 2743 hold_object(elm->obj); 2744 lock_release(rtld_bind_lock, lockstate); 2745 /* 2746 * It is legal to have both DT_FINI and DT_FINI_ARRAY defined. 2747 * When this happens, DT_FINI_ARRAY is processed first. 2748 */ 2749 fini_addr = (Elf_Addr *)elm->obj->fini_array; 2750 if (fini_addr != NULL && elm->obj->fini_array_num > 0) { 2751 for (index = elm->obj->fini_array_num - 1; index >= 0; 2752 index--) { 2753 if (fini_addr[index] != 0 && fini_addr[index] != 1) { 2754 dbg("calling fini function for %s at %p", 2755 elm->obj->path, (void *)fini_addr[index]); 2756 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, 2757 (void *)fini_addr[index], 0, 0, elm->obj->path); 2758 call_initfini_pointer(elm->obj, fini_addr[index]); 2759 } 2760 } 2761 } 2762 if (elm->obj->fini != (Elf_Addr)NULL) { 2763 dbg("calling fini function for %s at %p", elm->obj->path, 2764 (void *)elm->obj->fini); 2765 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, (void *)elm->obj->fini, 2766 0, 0, elm->obj->path); 2767 call_initfini_pointer(elm->obj, elm->obj->fini); 2768 } 2769 wlock_acquire(rtld_bind_lock, lockstate); 2770 unhold_object(elm->obj); 2771 /* No need to free anything if process is going down. */ 2772 if (root != NULL) 2773 free(elm); 2774 /* 2775 * We must restart the list traversal after every fini call 2776 * because a dlclose() call from the fini function or from 2777 * another thread might have modified the reference counts. 2778 */ 2779 break; 2780 } 2781 } while (elm != NULL); 2782 errmsg_restore(saved_msg); 2783 } 2784 2785 /* 2786 * Call the initialization functions for each of the objects in 2787 * "list". All of the objects are expected to have non-NULL init 2788 * functions. 2789 */ 2790 static void 2791 objlist_call_init(Objlist *list, RtldLockState *lockstate) 2792 { 2793 Objlist_Entry *elm; 2794 Obj_Entry *obj; 2795 char *saved_msg; 2796 Elf_Addr *init_addr; 2797 void (*reg)(void (*)(void)); 2798 int index; 2799 2800 /* 2801 * Clean init_scanned flag so that objects can be rechecked and 2802 * possibly initialized earlier if any of vectors called below 2803 * cause the change by using dlopen. 2804 */ 2805 TAILQ_FOREACH(obj, &obj_list, next) { 2806 if (obj->marker) 2807 continue; 2808 obj->init_scanned = false; 2809 } 2810 2811 /* 2812 * Preserve the current error message since an init function might 2813 * call into the dynamic linker and overwrite it. 2814 */ 2815 saved_msg = errmsg_save(); 2816 STAILQ_FOREACH(elm, list, link) { 2817 if (elm->obj->init_done) /* Initialized early. */ 2818 continue; 2819 /* 2820 * Race: other thread might try to use this object before current 2821 * one completes the initialization. Not much can be done here 2822 * without better locking. 2823 */ 2824 elm->obj->init_done = true; 2825 hold_object(elm->obj); 2826 reg = NULL; 2827 if (elm->obj == obj_main && obj_main->crt_no_init) { 2828 reg = (void (*)(void (*)(void)))get_program_var_addr( 2829 "__libc_atexit", lockstate); 2830 } 2831 lock_release(rtld_bind_lock, lockstate); 2832 if (reg != NULL) { 2833 reg(rtld_exit); 2834 rtld_exit_ptr = rtld_nop_exit; 2835 } 2836 2837 /* 2838 * It is legal to have both DT_INIT and DT_INIT_ARRAY defined. 2839 * When this happens, DT_INIT is processed first. 2840 */ 2841 if (elm->obj->init != (Elf_Addr)NULL) { 2842 dbg("calling init function for %s at %p", elm->obj->path, 2843 (void *)elm->obj->init); 2844 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, (void *)elm->obj->init, 2845 0, 0, elm->obj->path); 2846 call_init_pointer(elm->obj, elm->obj->init); 2847 } 2848 init_addr = (Elf_Addr *)elm->obj->init_array; 2849 if (init_addr != NULL) { 2850 for (index = 0; index < elm->obj->init_array_num; index++) { 2851 if (init_addr[index] != 0 && init_addr[index] != 1) { 2852 dbg("calling init function for %s at %p", elm->obj->path, 2853 (void *)init_addr[index]); 2854 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, 2855 (void *)init_addr[index], 0, 0, elm->obj->path); 2856 call_init_pointer(elm->obj, init_addr[index]); 2857 } 2858 } 2859 } 2860 wlock_acquire(rtld_bind_lock, lockstate); 2861 unhold_object(elm->obj); 2862 } 2863 errmsg_restore(saved_msg); 2864 } 2865 2866 static void 2867 objlist_clear(Objlist *list) 2868 { 2869 Objlist_Entry *elm; 2870 2871 while (!STAILQ_EMPTY(list)) { 2872 elm = STAILQ_FIRST(list); 2873 STAILQ_REMOVE_HEAD(list, link); 2874 free(elm); 2875 } 2876 } 2877 2878 static Objlist_Entry * 2879 objlist_find(Objlist *list, const Obj_Entry *obj) 2880 { 2881 Objlist_Entry *elm; 2882 2883 STAILQ_FOREACH(elm, list, link) 2884 if (elm->obj == obj) 2885 return elm; 2886 return NULL; 2887 } 2888 2889 static void 2890 objlist_init(Objlist *list) 2891 { 2892 STAILQ_INIT(list); 2893 } 2894 2895 static void 2896 objlist_push_head(Objlist *list, Obj_Entry *obj) 2897 { 2898 Objlist_Entry *elm; 2899 2900 elm = NEW(Objlist_Entry); 2901 elm->obj = obj; 2902 STAILQ_INSERT_HEAD(list, elm, link); 2903 } 2904 2905 static void 2906 objlist_push_tail(Objlist *list, Obj_Entry *obj) 2907 { 2908 Objlist_Entry *elm; 2909 2910 elm = NEW(Objlist_Entry); 2911 elm->obj = obj; 2912 STAILQ_INSERT_TAIL(list, elm, link); 2913 } 2914 2915 static void 2916 objlist_put_after(Objlist *list, Obj_Entry *listobj, Obj_Entry *obj) 2917 { 2918 Objlist_Entry *elm, *listelm; 2919 2920 STAILQ_FOREACH(listelm, list, link) { 2921 if (listelm->obj == listobj) 2922 break; 2923 } 2924 elm = NEW(Objlist_Entry); 2925 elm->obj = obj; 2926 if (listelm != NULL) 2927 STAILQ_INSERT_AFTER(list, listelm, elm, link); 2928 else 2929 STAILQ_INSERT_TAIL(list, elm, link); 2930 } 2931 2932 static void 2933 objlist_remove(Objlist *list, Obj_Entry *obj) 2934 { 2935 Objlist_Entry *elm; 2936 2937 if ((elm = objlist_find(list, obj)) != NULL) { 2938 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 2939 free(elm); 2940 } 2941 } 2942 2943 /* 2944 * Relocate dag rooted in the specified object. 2945 * Returns 0 on success, or -1 on failure. 2946 */ 2947 2948 static int 2949 relocate_object_dag(Obj_Entry *root, bool bind_now, Obj_Entry *rtldobj, 2950 int flags, RtldLockState *lockstate) 2951 { 2952 Objlist_Entry *elm; 2953 int error; 2954 2955 error = 0; 2956 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2957 error = relocate_object(elm->obj, bind_now, rtldobj, flags, 2958 lockstate); 2959 if (error == -1) 2960 break; 2961 } 2962 return (error); 2963 } 2964 2965 /* 2966 * Prepare for, or clean after, relocating an object marked with 2967 * DT_TEXTREL or DF_TEXTREL. Before relocating, all read-only 2968 * segments are remapped read-write. After relocations are done, the 2969 * segment's permissions are returned back to the modes specified in 2970 * the phdrs. If any relocation happened, or always for wired 2971 * program, COW is triggered. 2972 */ 2973 static int 2974 reloc_textrel_prot(Obj_Entry *obj, bool before) 2975 { 2976 const Elf_Phdr *ph; 2977 void *base; 2978 size_t l, sz; 2979 int prot; 2980 2981 for (l = obj->phsize / sizeof(*ph), ph = obj->phdr; l > 0; 2982 l--, ph++) { 2983 if (ph->p_type != PT_LOAD || (ph->p_flags & PF_W) != 0) 2984 continue; 2985 base = obj->relocbase + trunc_page(ph->p_vaddr); 2986 sz = round_page(ph->p_vaddr + ph->p_filesz) - 2987 trunc_page(ph->p_vaddr); 2988 prot = before ? (PROT_READ | PROT_WRITE) : 2989 convert_prot(ph->p_flags); 2990 if (mprotect(base, sz, prot) == -1) { 2991 _rtld_error("%s: Cannot write-%sable text segment: %s", 2992 obj->path, before ? "en" : "dis", 2993 rtld_strerror(errno)); 2994 return (-1); 2995 } 2996 } 2997 return (0); 2998 } 2999 3000 /* 3001 * Relocate single object. 3002 * Returns 0 on success, or -1 on failure. 3003 */ 3004 static int 3005 relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, 3006 int flags, RtldLockState *lockstate) 3007 { 3008 3009 if (obj->relocated) 3010 return (0); 3011 obj->relocated = true; 3012 if (obj != rtldobj) 3013 dbg("relocating \"%s\"", obj->path); 3014 3015 if (obj->symtab == NULL || obj->strtab == NULL || 3016 !(obj->valid_hash_sysv || obj->valid_hash_gnu)) 3017 dbg("object %s has no run-time symbol table", obj->path); 3018 3019 /* There are relocations to the write-protected text segment. */ 3020 if (obj->textrel && reloc_textrel_prot(obj, true) != 0) 3021 return (-1); 3022 3023 /* Process the non-PLT non-IFUNC relocations. */ 3024 if (reloc_non_plt(obj, rtldobj, flags, lockstate)) 3025 return (-1); 3026 3027 /* Re-protected the text segment. */ 3028 if (obj->textrel && reloc_textrel_prot(obj, false) != 0) 3029 return (-1); 3030 3031 /* Set the special PLT or GOT entries. */ 3032 init_pltgot(obj); 3033 3034 /* Process the PLT relocations. */ 3035 if (reloc_plt(obj, flags, lockstate) == -1) 3036 return (-1); 3037 /* Relocate the jump slots if we are doing immediate binding. */ 3038 if ((obj->bind_now || bind_now) && reloc_jmpslots(obj, flags, 3039 lockstate) == -1) 3040 return (-1); 3041 3042 if (!obj->mainprog && obj_enforce_relro(obj) == -1) 3043 return (-1); 3044 3045 /* 3046 * Set up the magic number and version in the Obj_Entry. These 3047 * were checked in the crt1.o from the original ElfKit, so we 3048 * set them for backward compatibility. 3049 */ 3050 obj->magic = RTLD_MAGIC; 3051 obj->version = RTLD_VERSION; 3052 3053 return (0); 3054 } 3055 3056 /* 3057 * Relocate newly-loaded shared objects. The argument is a pointer to 3058 * the Obj_Entry for the first such object. All objects from the first 3059 * to the end of the list of objects are relocated. Returns 0 on success, 3060 * or -1 on failure. 3061 */ 3062 static int 3063 relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj, 3064 int flags, RtldLockState *lockstate) 3065 { 3066 Obj_Entry *obj; 3067 int error; 3068 3069 for (error = 0, obj = first; obj != NULL; 3070 obj = TAILQ_NEXT(obj, next)) { 3071 if (obj->marker) 3072 continue; 3073 error = relocate_object(obj, bind_now, rtldobj, flags, 3074 lockstate); 3075 if (error == -1) 3076 break; 3077 } 3078 return (error); 3079 } 3080 3081 /* 3082 * The handling of R_MACHINE_IRELATIVE relocations and jumpslots 3083 * referencing STT_GNU_IFUNC symbols is postponed till the other 3084 * relocations are done. The indirect functions specified as 3085 * ifunc are allowed to call other symbols, so we need to have 3086 * objects relocated before asking for resolution from indirects. 3087 * 3088 * The R_MACHINE_IRELATIVE slots are resolved in greedy fashion, 3089 * instead of the usual lazy handling of PLT slots. It is 3090 * consistent with how GNU does it. 3091 */ 3092 static int 3093 resolve_object_ifunc(Obj_Entry *obj, bool bind_now, int flags, 3094 RtldLockState *lockstate) 3095 { 3096 3097 if (obj->ifuncs_resolved) 3098 return (0); 3099 obj->ifuncs_resolved = true; 3100 if (!obj->irelative && !obj->irelative_nonplt && 3101 !((obj->bind_now || bind_now) && obj->gnu_ifunc) && 3102 !obj->non_plt_gnu_ifunc) 3103 return (0); 3104 if (obj_disable_relro(obj) == -1 || 3105 (obj->irelative && reloc_iresolve(obj, lockstate) == -1) || 3106 (obj->irelative_nonplt && reloc_iresolve_nonplt(obj, 3107 lockstate) == -1) || 3108 ((obj->bind_now || bind_now) && obj->gnu_ifunc && 3109 reloc_gnu_ifunc(obj, flags, lockstate) == -1) || 3110 (obj->non_plt_gnu_ifunc && reloc_non_plt(obj, &obj_rtld, 3111 flags | SYMLOOK_IFUNC, lockstate) == -1) || 3112 obj_enforce_relro(obj) == -1) 3113 return (-1); 3114 return (0); 3115 } 3116 3117 static int 3118 initlist_objects_ifunc(Objlist *list, bool bind_now, int flags, 3119 RtldLockState *lockstate) 3120 { 3121 Objlist_Entry *elm; 3122 Obj_Entry *obj; 3123 3124 STAILQ_FOREACH(elm, list, link) { 3125 obj = elm->obj; 3126 if (obj->marker) 3127 continue; 3128 if (resolve_object_ifunc(obj, bind_now, flags, 3129 lockstate) == -1) 3130 return (-1); 3131 } 3132 return (0); 3133 } 3134 3135 /* 3136 * Cleanup procedure. It will be called (by the atexit mechanism) just 3137 * before the process exits. 3138 */ 3139 static void 3140 rtld_exit(void) 3141 { 3142 RtldLockState lockstate; 3143 3144 wlock_acquire(rtld_bind_lock, &lockstate); 3145 dbg("rtld_exit()"); 3146 objlist_call_fini(&list_fini, NULL, &lockstate); 3147 /* No need to remove the items from the list, since we are exiting. */ 3148 if (!libmap_disable) 3149 lm_fini(); 3150 lock_release(rtld_bind_lock, &lockstate); 3151 } 3152 3153 static void 3154 rtld_nop_exit(void) 3155 { 3156 } 3157 3158 /* 3159 * Iterate over a search path, translate each element, and invoke the 3160 * callback on the result. 3161 */ 3162 static void * 3163 path_enumerate(const char *path, path_enum_proc callback, 3164 const char *refobj_path, void *arg) 3165 { 3166 const char *trans; 3167 if (path == NULL) 3168 return (NULL); 3169 3170 path += strspn(path, ":;"); 3171 while (*path != '\0') { 3172 size_t len; 3173 char *res; 3174 3175 len = strcspn(path, ":;"); 3176 trans = lm_findn(refobj_path, path, len); 3177 if (trans) 3178 res = callback(trans, strlen(trans), arg); 3179 else 3180 res = callback(path, len, arg); 3181 3182 if (res != NULL) 3183 return (res); 3184 3185 path += len; 3186 path += strspn(path, ":;"); 3187 } 3188 3189 return (NULL); 3190 } 3191 3192 struct try_library_args { 3193 const char *name; 3194 size_t namelen; 3195 char *buffer; 3196 size_t buflen; 3197 int fd; 3198 }; 3199 3200 static void * 3201 try_library_path(const char *dir, size_t dirlen, void *param) 3202 { 3203 struct try_library_args *arg; 3204 int fd; 3205 3206 arg = param; 3207 if (*dir == '/' || trust) { 3208 char *pathname; 3209 3210 if (dirlen + 1 + arg->namelen + 1 > arg->buflen) 3211 return (NULL); 3212 3213 pathname = arg->buffer; 3214 strncpy(pathname, dir, dirlen); 3215 pathname[dirlen] = '/'; 3216 strcpy(pathname + dirlen + 1, arg->name); 3217 3218 dbg(" Trying \"%s\"", pathname); 3219 fd = open(pathname, O_RDONLY | O_CLOEXEC | O_VERIFY); 3220 if (fd >= 0) { 3221 dbg(" Opened \"%s\", fd %d", pathname, fd); 3222 pathname = xmalloc(dirlen + 1 + arg->namelen + 1); 3223 strcpy(pathname, arg->buffer); 3224 arg->fd = fd; 3225 return (pathname); 3226 } else { 3227 dbg(" Failed to open \"%s\": %s", 3228 pathname, rtld_strerror(errno)); 3229 } 3230 } 3231 return (NULL); 3232 } 3233 3234 static char * 3235 search_library_path(const char *name, const char *path, 3236 const char *refobj_path, int *fdp) 3237 { 3238 char *p; 3239 struct try_library_args arg; 3240 3241 if (path == NULL) 3242 return NULL; 3243 3244 arg.name = name; 3245 arg.namelen = strlen(name); 3246 arg.buffer = xmalloc(PATH_MAX); 3247 arg.buflen = PATH_MAX; 3248 arg.fd = -1; 3249 3250 p = path_enumerate(path, try_library_path, refobj_path, &arg); 3251 *fdp = arg.fd; 3252 3253 free(arg.buffer); 3254 3255 return (p); 3256 } 3257 3258 3259 /* 3260 * Finds the library with the given name using the directory descriptors 3261 * listed in the LD_LIBRARY_PATH_FDS environment variable. 3262 * 3263 * Returns a freshly-opened close-on-exec file descriptor for the library, 3264 * or -1 if the library cannot be found. 3265 */ 3266 static char * 3267 search_library_pathfds(const char *name, const char *path, int *fdp) 3268 { 3269 char *envcopy, *fdstr, *found, *last_token; 3270 size_t len; 3271 int dirfd, fd; 3272 3273 dbg("%s('%s', '%s', fdp)", __func__, name, path); 3274 3275 /* Don't load from user-specified libdirs into setuid binaries. */ 3276 if (!trust) 3277 return (NULL); 3278 3279 /* We can't do anything if LD_LIBRARY_PATH_FDS isn't set. */ 3280 if (path == NULL) 3281 return (NULL); 3282 3283 /* LD_LIBRARY_PATH_FDS only works with relative paths. */ 3284 if (name[0] == '/') { 3285 dbg("Absolute path (%s) passed to %s", name, __func__); 3286 return (NULL); 3287 } 3288 3289 /* 3290 * Use strtok_r() to walk the FD:FD:FD list. This requires a local 3291 * copy of the path, as strtok_r rewrites separator tokens 3292 * with '\0'. 3293 */ 3294 found = NULL; 3295 envcopy = xstrdup(path); 3296 for (fdstr = strtok_r(envcopy, ":", &last_token); fdstr != NULL; 3297 fdstr = strtok_r(NULL, ":", &last_token)) { 3298 dirfd = parse_integer(fdstr); 3299 if (dirfd < 0) { 3300 _rtld_error("failed to parse directory FD: '%s'", 3301 fdstr); 3302 break; 3303 } 3304 fd = __sys_openat(dirfd, name, O_RDONLY | O_CLOEXEC | O_VERIFY); 3305 if (fd >= 0) { 3306 *fdp = fd; 3307 len = strlen(fdstr) + strlen(name) + 3; 3308 found = xmalloc(len); 3309 if (rtld_snprintf(found, len, "#%d/%s", dirfd, name) < 0) { 3310 _rtld_error("error generating '%d/%s'", 3311 dirfd, name); 3312 rtld_die(); 3313 } 3314 dbg("open('%s') => %d", found, fd); 3315 break; 3316 } 3317 } 3318 free(envcopy); 3319 3320 return (found); 3321 } 3322 3323 3324 int 3325 dlclose(void *handle) 3326 { 3327 RtldLockState lockstate; 3328 int error; 3329 3330 wlock_acquire(rtld_bind_lock, &lockstate); 3331 error = dlclose_locked(handle, &lockstate); 3332 lock_release(rtld_bind_lock, &lockstate); 3333 return (error); 3334 } 3335 3336 static int 3337 dlclose_locked(void *handle, RtldLockState *lockstate) 3338 { 3339 Obj_Entry *root; 3340 3341 root = dlcheck(handle); 3342 if (root == NULL) 3343 return -1; 3344 LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount, 3345 root->path); 3346 3347 /* Unreference the object and its dependencies. */ 3348 root->dl_refcount--; 3349 3350 if (root->refcount == 1) { 3351 /* 3352 * The object will be no longer referenced, so we must unload it. 3353 * First, call the fini functions. 3354 */ 3355 objlist_call_fini(&list_fini, root, lockstate); 3356 3357 unref_dag(root); 3358 3359 /* Finish cleaning up the newly-unreferenced objects. */ 3360 GDB_STATE(RT_DELETE,&root->linkmap); 3361 unload_object(root, lockstate); 3362 GDB_STATE(RT_CONSISTENT,NULL); 3363 } else 3364 unref_dag(root); 3365 3366 LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL); 3367 return 0; 3368 } 3369 3370 char * 3371 dlerror(void) 3372 { 3373 if (*(lockinfo.dlerror_seen()) != 0) 3374 return (NULL); 3375 *lockinfo.dlerror_seen() = 1; 3376 return (lockinfo.dlerror_loc()); 3377 } 3378 3379 /* 3380 * This function is deprecated and has no effect. 3381 */ 3382 void 3383 dllockinit(void *context, 3384 void *(*_lock_create)(void *context) __unused, 3385 void (*_rlock_acquire)(void *lock) __unused, 3386 void (*_wlock_acquire)(void *lock) __unused, 3387 void (*_lock_release)(void *lock) __unused, 3388 void (*_lock_destroy)(void *lock) __unused, 3389 void (*context_destroy)(void *context)) 3390 { 3391 static void *cur_context; 3392 static void (*cur_context_destroy)(void *); 3393 3394 /* Just destroy the context from the previous call, if necessary. */ 3395 if (cur_context_destroy != NULL) 3396 cur_context_destroy(cur_context); 3397 cur_context = context; 3398 cur_context_destroy = context_destroy; 3399 } 3400 3401 void * 3402 dlopen(const char *name, int mode) 3403 { 3404 3405 return (rtld_dlopen(name, -1, mode)); 3406 } 3407 3408 void * 3409 fdlopen(int fd, int mode) 3410 { 3411 3412 return (rtld_dlopen(NULL, fd, mode)); 3413 } 3414 3415 static void * 3416 rtld_dlopen(const char *name, int fd, int mode) 3417 { 3418 RtldLockState lockstate; 3419 int lo_flags; 3420 3421 LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name); 3422 ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1"; 3423 if (ld_tracing != NULL) { 3424 rlock_acquire(rtld_bind_lock, &lockstate); 3425 if (sigsetjmp(lockstate.env, 0) != 0) 3426 lock_upgrade(rtld_bind_lock, &lockstate); 3427 environ = __DECONST(char **, *get_program_var_addr("environ", &lockstate)); 3428 lock_release(rtld_bind_lock, &lockstate); 3429 } 3430 lo_flags = RTLD_LO_DLOPEN; 3431 if (mode & RTLD_NODELETE) 3432 lo_flags |= RTLD_LO_NODELETE; 3433 if (mode & RTLD_NOLOAD) 3434 lo_flags |= RTLD_LO_NOLOAD; 3435 if (mode & RTLD_DEEPBIND) 3436 lo_flags |= RTLD_LO_DEEPBIND; 3437 if (ld_tracing != NULL) 3438 lo_flags |= RTLD_LO_TRACE | RTLD_LO_IGNSTLS; 3439 3440 return (dlopen_object(name, fd, obj_main, lo_flags, 3441 mode & (RTLD_MODEMASK | RTLD_GLOBAL), NULL)); 3442 } 3443 3444 static void 3445 dlopen_cleanup(Obj_Entry *obj, RtldLockState *lockstate) 3446 { 3447 3448 obj->dl_refcount--; 3449 unref_dag(obj); 3450 if (obj->refcount == 0) 3451 unload_object(obj, lockstate); 3452 } 3453 3454 static Obj_Entry * 3455 dlopen_object(const char *name, int fd, Obj_Entry *refobj, int lo_flags, 3456 int mode, RtldLockState *lockstate) 3457 { 3458 Obj_Entry *old_obj_tail; 3459 Obj_Entry *obj; 3460 Objlist initlist; 3461 RtldLockState mlockstate; 3462 int result; 3463 3464 dbg("dlopen_object name \"%s\" fd %d refobj \"%s\" lo_flags %#x mode %#x", 3465 name != NULL ? name : "<null>", fd, refobj == NULL ? "<null>" : 3466 refobj->path, lo_flags, mode); 3467 objlist_init(&initlist); 3468 3469 if (lockstate == NULL && !(lo_flags & RTLD_LO_EARLY)) { 3470 wlock_acquire(rtld_bind_lock, &mlockstate); 3471 lockstate = &mlockstate; 3472 } 3473 GDB_STATE(RT_ADD,NULL); 3474 3475 old_obj_tail = globallist_curr(TAILQ_LAST(&obj_list, obj_entry_q)); 3476 obj = NULL; 3477 if (name == NULL && fd == -1) { 3478 obj = obj_main; 3479 obj->refcount++; 3480 } else { 3481 obj = load_object(name, fd, refobj, lo_flags); 3482 } 3483 3484 if (obj) { 3485 obj->dl_refcount++; 3486 if (mode & RTLD_GLOBAL && objlist_find(&list_global, obj) == NULL) 3487 objlist_push_tail(&list_global, obj); 3488 if (globallist_next(old_obj_tail) != NULL) { 3489 /* We loaded something new. */ 3490 assert(globallist_next(old_obj_tail) == obj); 3491 if ((lo_flags & RTLD_LO_DEEPBIND) != 0) 3492 obj->symbolic = true; 3493 result = 0; 3494 if ((lo_flags & (RTLD_LO_EARLY | RTLD_LO_IGNSTLS)) == 0 && 3495 obj->static_tls && !allocate_tls_offset(obj)) { 3496 _rtld_error("%s: No space available " 3497 "for static Thread Local Storage", obj->path); 3498 result = -1; 3499 } 3500 if (result != -1) 3501 result = load_needed_objects(obj, lo_flags & (RTLD_LO_DLOPEN | 3502 RTLD_LO_EARLY | RTLD_LO_IGNSTLS | RTLD_LO_TRACE)); 3503 init_dag(obj); 3504 ref_dag(obj); 3505 if (result != -1) 3506 result = rtld_verify_versions(&obj->dagmembers); 3507 if (result != -1 && ld_tracing) 3508 goto trace; 3509 if (result == -1 || relocate_object_dag(obj, 3510 (mode & RTLD_MODEMASK) == RTLD_NOW, &obj_rtld, 3511 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 3512 lockstate) == -1) { 3513 dlopen_cleanup(obj, lockstate); 3514 obj = NULL; 3515 } else if (lo_flags & RTLD_LO_EARLY) { 3516 /* 3517 * Do not call the init functions for early loaded 3518 * filtees. The image is still not initialized enough 3519 * for them to work. 3520 * 3521 * Our object is found by the global object list and 3522 * will be ordered among all init calls done right 3523 * before transferring control to main. 3524 */ 3525 } else { 3526 /* Make list of init functions to call. */ 3527 initlist_add_objects(obj, obj, &initlist); 3528 } 3529 /* 3530 * Process all no_delete or global objects here, given 3531 * them own DAGs to prevent their dependencies from being 3532 * unloaded. This has to be done after we have loaded all 3533 * of the dependencies, so that we do not miss any. 3534 */ 3535 if (obj != NULL) 3536 process_z(obj); 3537 } else { 3538 /* 3539 * Bump the reference counts for objects on this DAG. If 3540 * this is the first dlopen() call for the object that was 3541 * already loaded as a dependency, initialize the dag 3542 * starting at it. 3543 */ 3544 init_dag(obj); 3545 ref_dag(obj); 3546 3547 if ((lo_flags & RTLD_LO_TRACE) != 0) 3548 goto trace; 3549 } 3550 if (obj != NULL && ((lo_flags & RTLD_LO_NODELETE) != 0 || 3551 obj->z_nodelete) && !obj->ref_nodel) { 3552 dbg("obj %s nodelete", obj->path); 3553 ref_dag(obj); 3554 obj->z_nodelete = obj->ref_nodel = true; 3555 } 3556 } 3557 3558 LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0, 3559 name); 3560 GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL); 3561 3562 if ((lo_flags & RTLD_LO_EARLY) == 0) { 3563 map_stacks_exec(lockstate); 3564 if (obj != NULL) 3565 distribute_static_tls(&initlist, lockstate); 3566 } 3567 3568 if (initlist_objects_ifunc(&initlist, (mode & RTLD_MODEMASK) == RTLD_NOW, 3569 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 3570 lockstate) == -1) { 3571 objlist_clear(&initlist); 3572 dlopen_cleanup(obj, lockstate); 3573 if (lockstate == &mlockstate) 3574 lock_release(rtld_bind_lock, lockstate); 3575 return (NULL); 3576 } 3577 3578 if (!(lo_flags & RTLD_LO_EARLY)) { 3579 /* Call the init functions. */ 3580 objlist_call_init(&initlist, lockstate); 3581 } 3582 objlist_clear(&initlist); 3583 if (lockstate == &mlockstate) 3584 lock_release(rtld_bind_lock, lockstate); 3585 return obj; 3586 trace: 3587 trace_loaded_objects(obj); 3588 if (lockstate == &mlockstate) 3589 lock_release(rtld_bind_lock, lockstate); 3590 exit(0); 3591 } 3592 3593 static void * 3594 do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve, 3595 int flags) 3596 { 3597 DoneList donelist; 3598 const Obj_Entry *obj, *defobj; 3599 const Elf_Sym *def; 3600 SymLook req; 3601 RtldLockState lockstate; 3602 tls_index ti; 3603 void *sym; 3604 int res; 3605 3606 def = NULL; 3607 defobj = NULL; 3608 symlook_init(&req, name); 3609 req.ventry = ve; 3610 req.flags = flags | SYMLOOK_IN_PLT; 3611 req.lockstate = &lockstate; 3612 3613 LD_UTRACE(UTRACE_DLSYM_START, handle, NULL, 0, 0, name); 3614 rlock_acquire(rtld_bind_lock, &lockstate); 3615 if (sigsetjmp(lockstate.env, 0) != 0) 3616 lock_upgrade(rtld_bind_lock, &lockstate); 3617 if (handle == NULL || handle == RTLD_NEXT || 3618 handle == RTLD_DEFAULT || handle == RTLD_SELF) { 3619 3620 if ((obj = obj_from_addr(retaddr)) == NULL) { 3621 _rtld_error("Cannot determine caller's shared object"); 3622 lock_release(rtld_bind_lock, &lockstate); 3623 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 3624 return NULL; 3625 } 3626 if (handle == NULL) { /* Just the caller's shared object. */ 3627 res = symlook_obj(&req, obj); 3628 if (res == 0) { 3629 def = req.sym_out; 3630 defobj = req.defobj_out; 3631 } 3632 } else if (handle == RTLD_NEXT || /* Objects after caller's */ 3633 handle == RTLD_SELF) { /* ... caller included */ 3634 if (handle == RTLD_NEXT) 3635 obj = globallist_next(obj); 3636 for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 3637 if (obj->marker) 3638 continue; 3639 res = symlook_obj(&req, obj); 3640 if (res == 0) { 3641 if (def == NULL || 3642 ELF_ST_BIND(req.sym_out->st_info) != STB_WEAK) { 3643 def = req.sym_out; 3644 defobj = req.defobj_out; 3645 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 3646 break; 3647 } 3648 } 3649 } 3650 /* 3651 * Search the dynamic linker itself, and possibly resolve the 3652 * symbol from there. This is how the application links to 3653 * dynamic linker services such as dlopen. 3654 */ 3655 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 3656 res = symlook_obj(&req, &obj_rtld); 3657 if (res == 0) { 3658 def = req.sym_out; 3659 defobj = req.defobj_out; 3660 } 3661 } 3662 } else { 3663 assert(handle == RTLD_DEFAULT); 3664 res = symlook_default(&req, obj); 3665 if (res == 0) { 3666 defobj = req.defobj_out; 3667 def = req.sym_out; 3668 } 3669 } 3670 } else { 3671 if ((obj = dlcheck(handle)) == NULL) { 3672 lock_release(rtld_bind_lock, &lockstate); 3673 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 3674 return NULL; 3675 } 3676 3677 donelist_init(&donelist); 3678 if (obj->mainprog) { 3679 /* Handle obtained by dlopen(NULL, ...) implies global scope. */ 3680 res = symlook_global(&req, &donelist); 3681 if (res == 0) { 3682 def = req.sym_out; 3683 defobj = req.defobj_out; 3684 } 3685 /* 3686 * Search the dynamic linker itself, and possibly resolve the 3687 * symbol from there. This is how the application links to 3688 * dynamic linker services such as dlopen. 3689 */ 3690 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 3691 res = symlook_obj(&req, &obj_rtld); 3692 if (res == 0) { 3693 def = req.sym_out; 3694 defobj = req.defobj_out; 3695 } 3696 } 3697 } 3698 else { 3699 /* Search the whole DAG rooted at the given object. */ 3700 res = symlook_list(&req, &obj->dagmembers, &donelist); 3701 if (res == 0) { 3702 def = req.sym_out; 3703 defobj = req.defobj_out; 3704 } 3705 } 3706 } 3707 3708 if (def != NULL) { 3709 lock_release(rtld_bind_lock, &lockstate); 3710 3711 /* 3712 * The value required by the caller is derived from the value 3713 * of the symbol. this is simply the relocated value of the 3714 * symbol. 3715 */ 3716 if (ELF_ST_TYPE(def->st_info) == STT_FUNC) 3717 sym = make_function_pointer(def, defobj); 3718 else if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 3719 sym = rtld_resolve_ifunc(defobj, def); 3720 else if (ELF_ST_TYPE(def->st_info) == STT_TLS) { 3721 ti.ti_module = defobj->tlsindex; 3722 ti.ti_offset = def->st_value; 3723 sym = __tls_get_addr(&ti); 3724 } else 3725 sym = defobj->relocbase + def->st_value; 3726 LD_UTRACE(UTRACE_DLSYM_STOP, handle, sym, 0, 0, name); 3727 return (sym); 3728 } 3729 3730 _rtld_error("Undefined symbol \"%s%s%s\"", name, ve != NULL ? "@" : "", 3731 ve != NULL ? ve->name : ""); 3732 lock_release(rtld_bind_lock, &lockstate); 3733 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 3734 return NULL; 3735 } 3736 3737 void * 3738 dlsym(void *handle, const char *name) 3739 { 3740 return do_dlsym(handle, name, __builtin_return_address(0), NULL, 3741 SYMLOOK_DLSYM); 3742 } 3743 3744 dlfunc_t 3745 dlfunc(void *handle, const char *name) 3746 { 3747 union { 3748 void *d; 3749 dlfunc_t f; 3750 } rv; 3751 3752 rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL, 3753 SYMLOOK_DLSYM); 3754 return (rv.f); 3755 } 3756 3757 void * 3758 dlvsym(void *handle, const char *name, const char *version) 3759 { 3760 Ver_Entry ventry; 3761 3762 ventry.name = version; 3763 ventry.file = NULL; 3764 ventry.hash = elf_hash(version); 3765 ventry.flags= 0; 3766 return do_dlsym(handle, name, __builtin_return_address(0), &ventry, 3767 SYMLOOK_DLSYM); 3768 } 3769 3770 int 3771 _rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info) 3772 { 3773 const Obj_Entry *obj; 3774 RtldLockState lockstate; 3775 3776 rlock_acquire(rtld_bind_lock, &lockstate); 3777 obj = obj_from_addr(addr); 3778 if (obj == NULL) { 3779 _rtld_error("No shared object contains address"); 3780 lock_release(rtld_bind_lock, &lockstate); 3781 return (0); 3782 } 3783 rtld_fill_dl_phdr_info(obj, phdr_info); 3784 lock_release(rtld_bind_lock, &lockstate); 3785 return (1); 3786 } 3787 3788 int 3789 dladdr(const void *addr, Dl_info *info) 3790 { 3791 const Obj_Entry *obj; 3792 const Elf_Sym *def; 3793 void *symbol_addr; 3794 unsigned long symoffset; 3795 RtldLockState lockstate; 3796 3797 rlock_acquire(rtld_bind_lock, &lockstate); 3798 obj = obj_from_addr(addr); 3799 if (obj == NULL) { 3800 _rtld_error("No shared object contains address"); 3801 lock_release(rtld_bind_lock, &lockstate); 3802 return 0; 3803 } 3804 info->dli_fname = obj->path; 3805 info->dli_fbase = obj->mapbase; 3806 info->dli_saddr = (void *)0; 3807 info->dli_sname = NULL; 3808 3809 /* 3810 * Walk the symbol list looking for the symbol whose address is 3811 * closest to the address sent in. 3812 */ 3813 for (symoffset = 0; symoffset < obj->dynsymcount; symoffset++) { 3814 def = obj->symtab + symoffset; 3815 3816 /* 3817 * For skip the symbol if st_shndx is either SHN_UNDEF or 3818 * SHN_COMMON. 3819 */ 3820 if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON) 3821 continue; 3822 3823 /* 3824 * If the symbol is greater than the specified address, or if it 3825 * is further away from addr than the current nearest symbol, 3826 * then reject it. 3827 */ 3828 symbol_addr = obj->relocbase + def->st_value; 3829 if (symbol_addr > addr || symbol_addr < info->dli_saddr) 3830 continue; 3831 3832 /* Update our idea of the nearest symbol. */ 3833 info->dli_sname = obj->strtab + def->st_name; 3834 info->dli_saddr = symbol_addr; 3835 3836 /* Exact match? */ 3837 if (info->dli_saddr == addr) 3838 break; 3839 } 3840 lock_release(rtld_bind_lock, &lockstate); 3841 return 1; 3842 } 3843 3844 int 3845 dlinfo(void *handle, int request, void *p) 3846 { 3847 const Obj_Entry *obj; 3848 RtldLockState lockstate; 3849 int error; 3850 3851 rlock_acquire(rtld_bind_lock, &lockstate); 3852 3853 if (handle == NULL || handle == RTLD_SELF) { 3854 void *retaddr; 3855 3856 retaddr = __builtin_return_address(0); /* __GNUC__ only */ 3857 if ((obj = obj_from_addr(retaddr)) == NULL) 3858 _rtld_error("Cannot determine caller's shared object"); 3859 } else 3860 obj = dlcheck(handle); 3861 3862 if (obj == NULL) { 3863 lock_release(rtld_bind_lock, &lockstate); 3864 return (-1); 3865 } 3866 3867 error = 0; 3868 switch (request) { 3869 case RTLD_DI_LINKMAP: 3870 *((struct link_map const **)p) = &obj->linkmap; 3871 break; 3872 case RTLD_DI_ORIGIN: 3873 error = rtld_dirname(obj->path, p); 3874 break; 3875 3876 case RTLD_DI_SERINFOSIZE: 3877 case RTLD_DI_SERINFO: 3878 error = do_search_info(obj, request, (struct dl_serinfo *)p); 3879 break; 3880 3881 default: 3882 _rtld_error("Invalid request %d passed to dlinfo()", request); 3883 error = -1; 3884 } 3885 3886 lock_release(rtld_bind_lock, &lockstate); 3887 3888 return (error); 3889 } 3890 3891 static void 3892 rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info) 3893 { 3894 Elf_Addr **dtvp; 3895 3896 phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase; 3897 phdr_info->dlpi_name = obj->path; 3898 phdr_info->dlpi_phdr = obj->phdr; 3899 phdr_info->dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]); 3900 phdr_info->dlpi_tls_modid = obj->tlsindex; 3901 dtvp = _get_tp(); 3902 phdr_info->dlpi_tls_data = (char *)tls_get_addr_slow(dtvp, 3903 obj->tlsindex, 0, true) + TLS_DTV_OFFSET; 3904 phdr_info->dlpi_adds = obj_loads; 3905 phdr_info->dlpi_subs = obj_loads - obj_count; 3906 } 3907 3908 int 3909 dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param) 3910 { 3911 struct dl_phdr_info phdr_info; 3912 Obj_Entry *obj, marker; 3913 RtldLockState bind_lockstate, phdr_lockstate; 3914 int error; 3915 3916 init_marker(&marker); 3917 error = 0; 3918 3919 wlock_acquire(rtld_phdr_lock, &phdr_lockstate); 3920 wlock_acquire(rtld_bind_lock, &bind_lockstate); 3921 for (obj = globallist_curr(TAILQ_FIRST(&obj_list)); obj != NULL;) { 3922 TAILQ_INSERT_AFTER(&obj_list, obj, &marker, next); 3923 rtld_fill_dl_phdr_info(obj, &phdr_info); 3924 hold_object(obj); 3925 lock_release(rtld_bind_lock, &bind_lockstate); 3926 3927 error = callback(&phdr_info, sizeof phdr_info, param); 3928 3929 wlock_acquire(rtld_bind_lock, &bind_lockstate); 3930 unhold_object(obj); 3931 obj = globallist_next(&marker); 3932 TAILQ_REMOVE(&obj_list, &marker, next); 3933 if (error != 0) { 3934 lock_release(rtld_bind_lock, &bind_lockstate); 3935 lock_release(rtld_phdr_lock, &phdr_lockstate); 3936 return (error); 3937 } 3938 } 3939 3940 if (error == 0) { 3941 rtld_fill_dl_phdr_info(&obj_rtld, &phdr_info); 3942 lock_release(rtld_bind_lock, &bind_lockstate); 3943 error = callback(&phdr_info, sizeof(phdr_info), param); 3944 } 3945 lock_release(rtld_phdr_lock, &phdr_lockstate); 3946 return (error); 3947 } 3948 3949 static void * 3950 fill_search_info(const char *dir, size_t dirlen, void *param) 3951 { 3952 struct fill_search_info_args *arg; 3953 3954 arg = param; 3955 3956 if (arg->request == RTLD_DI_SERINFOSIZE) { 3957 arg->serinfo->dls_cnt ++; 3958 arg->serinfo->dls_size += sizeof(struct dl_serpath) + dirlen + 1; 3959 } else { 3960 struct dl_serpath *s_entry; 3961 3962 s_entry = arg->serpath; 3963 s_entry->dls_name = arg->strspace; 3964 s_entry->dls_flags = arg->flags; 3965 3966 strncpy(arg->strspace, dir, dirlen); 3967 arg->strspace[dirlen] = '\0'; 3968 3969 arg->strspace += dirlen + 1; 3970 arg->serpath++; 3971 } 3972 3973 return (NULL); 3974 } 3975 3976 static int 3977 do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info) 3978 { 3979 struct dl_serinfo _info; 3980 struct fill_search_info_args args; 3981 3982 args.request = RTLD_DI_SERINFOSIZE; 3983 args.serinfo = &_info; 3984 3985 _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 3986 _info.dls_cnt = 0; 3987 3988 path_enumerate(obj->rpath, fill_search_info, NULL, &args); 3989 path_enumerate(ld_library_path, fill_search_info, NULL, &args); 3990 path_enumerate(obj->runpath, fill_search_info, NULL, &args); 3991 path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, &args); 3992 if (!obj->z_nodeflib) 3993 path_enumerate(ld_standard_library_path, fill_search_info, NULL, &args); 3994 3995 3996 if (request == RTLD_DI_SERINFOSIZE) { 3997 info->dls_size = _info.dls_size; 3998 info->dls_cnt = _info.dls_cnt; 3999 return (0); 4000 } 4001 4002 if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) { 4003 _rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()"); 4004 return (-1); 4005 } 4006 4007 args.request = RTLD_DI_SERINFO; 4008 args.serinfo = info; 4009 args.serpath = &info->dls_serpath[0]; 4010 args.strspace = (char *)&info->dls_serpath[_info.dls_cnt]; 4011 4012 args.flags = LA_SER_RUNPATH; 4013 if (path_enumerate(obj->rpath, fill_search_info, NULL, &args) != NULL) 4014 return (-1); 4015 4016 args.flags = LA_SER_LIBPATH; 4017 if (path_enumerate(ld_library_path, fill_search_info, NULL, &args) != NULL) 4018 return (-1); 4019 4020 args.flags = LA_SER_RUNPATH; 4021 if (path_enumerate(obj->runpath, fill_search_info, NULL, &args) != NULL) 4022 return (-1); 4023 4024 args.flags = LA_SER_CONFIG; 4025 if (path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, &args) 4026 != NULL) 4027 return (-1); 4028 4029 args.flags = LA_SER_DEFAULT; 4030 if (!obj->z_nodeflib && path_enumerate(ld_standard_library_path, 4031 fill_search_info, NULL, &args) != NULL) 4032 return (-1); 4033 return (0); 4034 } 4035 4036 static int 4037 rtld_dirname(const char *path, char *bname) 4038 { 4039 const char *endp; 4040 4041 /* Empty or NULL string gets treated as "." */ 4042 if (path == NULL || *path == '\0') { 4043 bname[0] = '.'; 4044 bname[1] = '\0'; 4045 return (0); 4046 } 4047 4048 /* Strip trailing slashes */ 4049 endp = path + strlen(path) - 1; 4050 while (endp > path && *endp == '/') 4051 endp--; 4052 4053 /* Find the start of the dir */ 4054 while (endp > path && *endp != '/') 4055 endp--; 4056 4057 /* Either the dir is "/" or there are no slashes */ 4058 if (endp == path) { 4059 bname[0] = *endp == '/' ? '/' : '.'; 4060 bname[1] = '\0'; 4061 return (0); 4062 } else { 4063 do { 4064 endp--; 4065 } while (endp > path && *endp == '/'); 4066 } 4067 4068 if (endp - path + 2 > PATH_MAX) 4069 { 4070 _rtld_error("Filename is too long: %s", path); 4071 return(-1); 4072 } 4073 4074 strncpy(bname, path, endp - path + 1); 4075 bname[endp - path + 1] = '\0'; 4076 return (0); 4077 } 4078 4079 static int 4080 rtld_dirname_abs(const char *path, char *base) 4081 { 4082 char *last; 4083 4084 if (realpath(path, base) == NULL) { 4085 _rtld_error("realpath \"%s\" failed (%s)", path, 4086 rtld_strerror(errno)); 4087 return (-1); 4088 } 4089 dbg("%s -> %s", path, base); 4090 last = strrchr(base, '/'); 4091 if (last == NULL) { 4092 _rtld_error("non-abs result from realpath \"%s\"", path); 4093 return (-1); 4094 } 4095 if (last != base) 4096 *last = '\0'; 4097 return (0); 4098 } 4099 4100 static void 4101 linkmap_add(Obj_Entry *obj) 4102 { 4103 struct link_map *l, *prev; 4104 4105 l = &obj->linkmap; 4106 l->l_name = obj->path; 4107 l->l_base = obj->mapbase; 4108 l->l_ld = obj->dynamic; 4109 l->l_addr = obj->relocbase; 4110 4111 if (r_debug.r_map == NULL) { 4112 r_debug.r_map = l; 4113 return; 4114 } 4115 4116 /* 4117 * Scan to the end of the list, but not past the entry for the 4118 * dynamic linker, which we want to keep at the very end. 4119 */ 4120 for (prev = r_debug.r_map; 4121 prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap; 4122 prev = prev->l_next) 4123 ; 4124 4125 /* Link in the new entry. */ 4126 l->l_prev = prev; 4127 l->l_next = prev->l_next; 4128 if (l->l_next != NULL) 4129 l->l_next->l_prev = l; 4130 prev->l_next = l; 4131 } 4132 4133 static void 4134 linkmap_delete(Obj_Entry *obj) 4135 { 4136 struct link_map *l; 4137 4138 l = &obj->linkmap; 4139 if (l->l_prev == NULL) { 4140 if ((r_debug.r_map = l->l_next) != NULL) 4141 l->l_next->l_prev = NULL; 4142 return; 4143 } 4144 4145 if ((l->l_prev->l_next = l->l_next) != NULL) 4146 l->l_next->l_prev = l->l_prev; 4147 } 4148 4149 /* 4150 * Function for the debugger to set a breakpoint on to gain control. 4151 * 4152 * The two parameters allow the debugger to easily find and determine 4153 * what the runtime loader is doing and to whom it is doing it. 4154 * 4155 * When the loadhook trap is hit (r_debug_state, set at program 4156 * initialization), the arguments can be found on the stack: 4157 * 4158 * +8 struct link_map *m 4159 * +4 struct r_debug *rd 4160 * +0 RetAddr 4161 */ 4162 void 4163 r_debug_state(struct r_debug* rd __unused, struct link_map *m __unused) 4164 { 4165 /* 4166 * The following is a hack to force the compiler to emit calls to 4167 * this function, even when optimizing. If the function is empty, 4168 * the compiler is not obliged to emit any code for calls to it, 4169 * even when marked __noinline. However, gdb depends on those 4170 * calls being made. 4171 */ 4172 __compiler_membar(); 4173 } 4174 4175 /* 4176 * A function called after init routines have completed. This can be used to 4177 * break before a program's entry routine is called, and can be used when 4178 * main is not available in the symbol table. 4179 */ 4180 void 4181 _r_debug_postinit(struct link_map *m __unused) 4182 { 4183 4184 /* See r_debug_state(). */ 4185 __compiler_membar(); 4186 } 4187 4188 static void 4189 release_object(Obj_Entry *obj) 4190 { 4191 4192 if (obj->holdcount > 0) { 4193 obj->unholdfree = true; 4194 return; 4195 } 4196 munmap(obj->mapbase, obj->mapsize); 4197 linkmap_delete(obj); 4198 obj_free(obj); 4199 } 4200 4201 /* 4202 * Get address of the pointer variable in the main program. 4203 * Prefer non-weak symbol over the weak one. 4204 */ 4205 static const void ** 4206 get_program_var_addr(const char *name, RtldLockState *lockstate) 4207 { 4208 SymLook req; 4209 DoneList donelist; 4210 4211 symlook_init(&req, name); 4212 req.lockstate = lockstate; 4213 donelist_init(&donelist); 4214 if (symlook_global(&req, &donelist) != 0) 4215 return (NULL); 4216 if (ELF_ST_TYPE(req.sym_out->st_info) == STT_FUNC) 4217 return ((const void **)make_function_pointer(req.sym_out, 4218 req.defobj_out)); 4219 else if (ELF_ST_TYPE(req.sym_out->st_info) == STT_GNU_IFUNC) 4220 return ((const void **)rtld_resolve_ifunc(req.defobj_out, req.sym_out)); 4221 else 4222 return ((const void **)(req.defobj_out->relocbase + 4223 req.sym_out->st_value)); 4224 } 4225 4226 /* 4227 * Set a pointer variable in the main program to the given value. This 4228 * is used to set key variables such as "environ" before any of the 4229 * init functions are called. 4230 */ 4231 static void 4232 set_program_var(const char *name, const void *value) 4233 { 4234 const void **addr; 4235 4236 if ((addr = get_program_var_addr(name, NULL)) != NULL) { 4237 dbg("\"%s\": *%p <-- %p", name, addr, value); 4238 *addr = value; 4239 } 4240 } 4241 4242 /* 4243 * Search the global objects, including dependencies and main object, 4244 * for the given symbol. 4245 */ 4246 static int 4247 symlook_global(SymLook *req, DoneList *donelist) 4248 { 4249 SymLook req1; 4250 const Objlist_Entry *elm; 4251 int res; 4252 4253 symlook_init_from_req(&req1, req); 4254 4255 /* Search all objects loaded at program start up. */ 4256 if (req->defobj_out == NULL || 4257 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 4258 res = symlook_list(&req1, &list_main, donelist); 4259 if (res == 0 && (req->defobj_out == NULL || 4260 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4261 req->sym_out = req1.sym_out; 4262 req->defobj_out = req1.defobj_out; 4263 assert(req->defobj_out != NULL); 4264 } 4265 } 4266 4267 /* Search all DAGs whose roots are RTLD_GLOBAL objects. */ 4268 STAILQ_FOREACH(elm, &list_global, link) { 4269 if (req->defobj_out != NULL && 4270 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK) 4271 break; 4272 res = symlook_list(&req1, &elm->obj->dagmembers, donelist); 4273 if (res == 0 && (req->defobj_out == NULL || 4274 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4275 req->sym_out = req1.sym_out; 4276 req->defobj_out = req1.defobj_out; 4277 assert(req->defobj_out != NULL); 4278 } 4279 } 4280 4281 return (req->sym_out != NULL ? 0 : ESRCH); 4282 } 4283 4284 /* 4285 * Given a symbol name in a referencing object, find the corresponding 4286 * definition of the symbol. Returns a pointer to the symbol, or NULL if 4287 * no definition was found. Returns a pointer to the Obj_Entry of the 4288 * defining object via the reference parameter DEFOBJ_OUT. 4289 */ 4290 static int 4291 symlook_default(SymLook *req, const Obj_Entry *refobj) 4292 { 4293 DoneList donelist; 4294 const Objlist_Entry *elm; 4295 SymLook req1; 4296 int res; 4297 4298 donelist_init(&donelist); 4299 symlook_init_from_req(&req1, req); 4300 4301 /* 4302 * Look first in the referencing object if linked symbolically, 4303 * and similarly handle protected symbols. 4304 */ 4305 res = symlook_obj(&req1, refobj); 4306 if (res == 0 && (refobj->symbolic || 4307 ELF_ST_VISIBILITY(req1.sym_out->st_other) == STV_PROTECTED)) { 4308 req->sym_out = req1.sym_out; 4309 req->defobj_out = req1.defobj_out; 4310 assert(req->defobj_out != NULL); 4311 } 4312 if (refobj->symbolic || req->defobj_out != NULL) 4313 donelist_check(&donelist, refobj); 4314 4315 symlook_global(req, &donelist); 4316 4317 /* Search all dlopened DAGs containing the referencing object. */ 4318 STAILQ_FOREACH(elm, &refobj->dldags, link) { 4319 if (req->sym_out != NULL && 4320 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK) 4321 break; 4322 res = symlook_list(&req1, &elm->obj->dagmembers, &donelist); 4323 if (res == 0 && (req->sym_out == NULL || 4324 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4325 req->sym_out = req1.sym_out; 4326 req->defobj_out = req1.defobj_out; 4327 assert(req->defobj_out != NULL); 4328 } 4329 } 4330 4331 /* 4332 * Search the dynamic linker itself, and possibly resolve the 4333 * symbol from there. This is how the application links to 4334 * dynamic linker services such as dlopen. 4335 */ 4336 if (req->sym_out == NULL || 4337 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 4338 res = symlook_obj(&req1, &obj_rtld); 4339 if (res == 0) { 4340 req->sym_out = req1.sym_out; 4341 req->defobj_out = req1.defobj_out; 4342 assert(req->defobj_out != NULL); 4343 } 4344 } 4345 4346 return (req->sym_out != NULL ? 0 : ESRCH); 4347 } 4348 4349 static int 4350 symlook_list(SymLook *req, const Objlist *objlist, DoneList *dlp) 4351 { 4352 const Elf_Sym *def; 4353 const Obj_Entry *defobj; 4354 const Objlist_Entry *elm; 4355 SymLook req1; 4356 int res; 4357 4358 def = NULL; 4359 defobj = NULL; 4360 STAILQ_FOREACH(elm, objlist, link) { 4361 if (donelist_check(dlp, elm->obj)) 4362 continue; 4363 symlook_init_from_req(&req1, req); 4364 if ((res = symlook_obj(&req1, elm->obj)) == 0) { 4365 if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) { 4366 def = req1.sym_out; 4367 defobj = req1.defobj_out; 4368 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 4369 break; 4370 } 4371 } 4372 } 4373 if (def != NULL) { 4374 req->sym_out = def; 4375 req->defobj_out = defobj; 4376 return (0); 4377 } 4378 return (ESRCH); 4379 } 4380 4381 /* 4382 * Search the chain of DAGS cointed to by the given Needed_Entry 4383 * for a symbol of the given name. Each DAG is scanned completely 4384 * before advancing to the next one. Returns a pointer to the symbol, 4385 * or NULL if no definition was found. 4386 */ 4387 static int 4388 symlook_needed(SymLook *req, const Needed_Entry *needed, DoneList *dlp) 4389 { 4390 const Elf_Sym *def; 4391 const Needed_Entry *n; 4392 const Obj_Entry *defobj; 4393 SymLook req1; 4394 int res; 4395 4396 def = NULL; 4397 defobj = NULL; 4398 symlook_init_from_req(&req1, req); 4399 for (n = needed; n != NULL; n = n->next) { 4400 if (n->obj == NULL || 4401 (res = symlook_list(&req1, &n->obj->dagmembers, dlp)) != 0) 4402 continue; 4403 if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) { 4404 def = req1.sym_out; 4405 defobj = req1.defobj_out; 4406 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 4407 break; 4408 } 4409 } 4410 if (def != NULL) { 4411 req->sym_out = def; 4412 req->defobj_out = defobj; 4413 return (0); 4414 } 4415 return (ESRCH); 4416 } 4417 4418 /* 4419 * Search the symbol table of a single shared object for a symbol of 4420 * the given name and version, if requested. Returns a pointer to the 4421 * symbol, or NULL if no definition was found. If the object is 4422 * filter, return filtered symbol from filtee. 4423 * 4424 * The symbol's hash value is passed in for efficiency reasons; that 4425 * eliminates many recomputations of the hash value. 4426 */ 4427 int 4428 symlook_obj(SymLook *req, const Obj_Entry *obj) 4429 { 4430 DoneList donelist; 4431 SymLook req1; 4432 int flags, res, mres; 4433 4434 /* 4435 * If there is at least one valid hash at this point, we prefer to 4436 * use the faster GNU version if available. 4437 */ 4438 if (obj->valid_hash_gnu) 4439 mres = symlook_obj1_gnu(req, obj); 4440 else if (obj->valid_hash_sysv) 4441 mres = symlook_obj1_sysv(req, obj); 4442 else 4443 return (EINVAL); 4444 4445 if (mres == 0) { 4446 if (obj->needed_filtees != NULL) { 4447 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; 4448 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 4449 donelist_init(&donelist); 4450 symlook_init_from_req(&req1, req); 4451 res = symlook_needed(&req1, obj->needed_filtees, &donelist); 4452 if (res == 0) { 4453 req->sym_out = req1.sym_out; 4454 req->defobj_out = req1.defobj_out; 4455 } 4456 return (res); 4457 } 4458 if (obj->needed_aux_filtees != NULL) { 4459 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; 4460 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 4461 donelist_init(&donelist); 4462 symlook_init_from_req(&req1, req); 4463 res = symlook_needed(&req1, obj->needed_aux_filtees, &donelist); 4464 if (res == 0) { 4465 req->sym_out = req1.sym_out; 4466 req->defobj_out = req1.defobj_out; 4467 return (res); 4468 } 4469 } 4470 } 4471 return (mres); 4472 } 4473 4474 /* Symbol match routine common to both hash functions */ 4475 static bool 4476 matched_symbol(SymLook *req, const Obj_Entry *obj, Sym_Match_Result *result, 4477 const unsigned long symnum) 4478 { 4479 Elf_Versym verndx; 4480 const Elf_Sym *symp; 4481 const char *strp; 4482 4483 symp = obj->symtab + symnum; 4484 strp = obj->strtab + symp->st_name; 4485 4486 switch (ELF_ST_TYPE(symp->st_info)) { 4487 case STT_FUNC: 4488 case STT_NOTYPE: 4489 case STT_OBJECT: 4490 case STT_COMMON: 4491 case STT_GNU_IFUNC: 4492 if (symp->st_value == 0) 4493 return (false); 4494 /* fallthrough */ 4495 case STT_TLS: 4496 if (symp->st_shndx != SHN_UNDEF) 4497 break; 4498 #ifndef __mips__ 4499 else if (((req->flags & SYMLOOK_IN_PLT) == 0) && 4500 (ELF_ST_TYPE(symp->st_info) == STT_FUNC)) 4501 break; 4502 #endif 4503 /* fallthrough */ 4504 default: 4505 return (false); 4506 } 4507 if (req->name[0] != strp[0] || strcmp(req->name, strp) != 0) 4508 return (false); 4509 4510 if (req->ventry == NULL) { 4511 if (obj->versyms != NULL) { 4512 verndx = VER_NDX(obj->versyms[symnum]); 4513 if (verndx > obj->vernum) { 4514 _rtld_error( 4515 "%s: symbol %s references wrong version %d", 4516 obj->path, obj->strtab + symnum, verndx); 4517 return (false); 4518 } 4519 /* 4520 * If we are not called from dlsym (i.e. this 4521 * is a normal relocation from unversioned 4522 * binary), accept the symbol immediately if 4523 * it happens to have first version after this 4524 * shared object became versioned. Otherwise, 4525 * if symbol is versioned and not hidden, 4526 * remember it. If it is the only symbol with 4527 * this name exported by the shared object, it 4528 * will be returned as a match by the calling 4529 * function. If symbol is global (verndx < 2) 4530 * accept it unconditionally. 4531 */ 4532 if ((req->flags & SYMLOOK_DLSYM) == 0 && 4533 verndx == VER_NDX_GIVEN) { 4534 result->sym_out = symp; 4535 return (true); 4536 } 4537 else if (verndx >= VER_NDX_GIVEN) { 4538 if ((obj->versyms[symnum] & VER_NDX_HIDDEN) 4539 == 0) { 4540 if (result->vsymp == NULL) 4541 result->vsymp = symp; 4542 result->vcount++; 4543 } 4544 return (false); 4545 } 4546 } 4547 result->sym_out = symp; 4548 return (true); 4549 } 4550 if (obj->versyms == NULL) { 4551 if (object_match_name(obj, req->ventry->name)) { 4552 _rtld_error("%s: object %s should provide version %s " 4553 "for symbol %s", obj_rtld.path, obj->path, 4554 req->ventry->name, obj->strtab + symnum); 4555 return (false); 4556 } 4557 } else { 4558 verndx = VER_NDX(obj->versyms[symnum]); 4559 if (verndx > obj->vernum) { 4560 _rtld_error("%s: symbol %s references wrong version %d", 4561 obj->path, obj->strtab + symnum, verndx); 4562 return (false); 4563 } 4564 if (obj->vertab[verndx].hash != req->ventry->hash || 4565 strcmp(obj->vertab[verndx].name, req->ventry->name)) { 4566 /* 4567 * Version does not match. Look if this is a 4568 * global symbol and if it is not hidden. If 4569 * global symbol (verndx < 2) is available, 4570 * use it. Do not return symbol if we are 4571 * called by dlvsym, because dlvsym looks for 4572 * a specific version and default one is not 4573 * what dlvsym wants. 4574 */ 4575 if ((req->flags & SYMLOOK_DLSYM) || 4576 (verndx >= VER_NDX_GIVEN) || 4577 (obj->versyms[symnum] & VER_NDX_HIDDEN)) 4578 return (false); 4579 } 4580 } 4581 result->sym_out = symp; 4582 return (true); 4583 } 4584 4585 /* 4586 * Search for symbol using SysV hash function. 4587 * obj->buckets is known not to be NULL at this point; the test for this was 4588 * performed with the obj->valid_hash_sysv assignment. 4589 */ 4590 static int 4591 symlook_obj1_sysv(SymLook *req, const Obj_Entry *obj) 4592 { 4593 unsigned long symnum; 4594 Sym_Match_Result matchres; 4595 4596 matchres.sym_out = NULL; 4597 matchres.vsymp = NULL; 4598 matchres.vcount = 0; 4599 4600 for (symnum = obj->buckets[req->hash % obj->nbuckets]; 4601 symnum != STN_UNDEF; symnum = obj->chains[symnum]) { 4602 if (symnum >= obj->nchains) 4603 return (ESRCH); /* Bad object */ 4604 4605 if (matched_symbol(req, obj, &matchres, symnum)) { 4606 req->sym_out = matchres.sym_out; 4607 req->defobj_out = obj; 4608 return (0); 4609 } 4610 } 4611 if (matchres.vcount == 1) { 4612 req->sym_out = matchres.vsymp; 4613 req->defobj_out = obj; 4614 return (0); 4615 } 4616 return (ESRCH); 4617 } 4618 4619 /* Search for symbol using GNU hash function */ 4620 static int 4621 symlook_obj1_gnu(SymLook *req, const Obj_Entry *obj) 4622 { 4623 Elf_Addr bloom_word; 4624 const Elf32_Word *hashval; 4625 Elf32_Word bucket; 4626 Sym_Match_Result matchres; 4627 unsigned int h1, h2; 4628 unsigned long symnum; 4629 4630 matchres.sym_out = NULL; 4631 matchres.vsymp = NULL; 4632 matchres.vcount = 0; 4633 4634 /* Pick right bitmask word from Bloom filter array */ 4635 bloom_word = obj->bloom_gnu[(req->hash_gnu / __ELF_WORD_SIZE) & 4636 obj->maskwords_bm_gnu]; 4637 4638 /* Calculate modulus word size of gnu hash and its derivative */ 4639 h1 = req->hash_gnu & (__ELF_WORD_SIZE - 1); 4640 h2 = ((req->hash_gnu >> obj->shift2_gnu) & (__ELF_WORD_SIZE - 1)); 4641 4642 /* Filter out the "definitely not in set" queries */ 4643 if (((bloom_word >> h1) & (bloom_word >> h2) & 1) == 0) 4644 return (ESRCH); 4645 4646 /* Locate hash chain and corresponding value element*/ 4647 bucket = obj->buckets_gnu[req->hash_gnu % obj->nbuckets_gnu]; 4648 if (bucket == 0) 4649 return (ESRCH); 4650 hashval = &obj->chain_zero_gnu[bucket]; 4651 do { 4652 if (((*hashval ^ req->hash_gnu) >> 1) == 0) { 4653 symnum = hashval - obj->chain_zero_gnu; 4654 if (matched_symbol(req, obj, &matchres, symnum)) { 4655 req->sym_out = matchres.sym_out; 4656 req->defobj_out = obj; 4657 return (0); 4658 } 4659 } 4660 } while ((*hashval++ & 1) == 0); 4661 if (matchres.vcount == 1) { 4662 req->sym_out = matchres.vsymp; 4663 req->defobj_out = obj; 4664 return (0); 4665 } 4666 return (ESRCH); 4667 } 4668 4669 static void 4670 trace_loaded_objects(Obj_Entry *obj) 4671 { 4672 const char *fmt1, *fmt2, *fmt, *main_local, *list_containers; 4673 int c; 4674 4675 if ((main_local = getenv(_LD("TRACE_LOADED_OBJECTS_PROGNAME"))) == NULL) 4676 main_local = ""; 4677 4678 if ((fmt1 = getenv(_LD("TRACE_LOADED_OBJECTS_FMT1"))) == NULL) 4679 fmt1 = "\t%o => %p (%x)\n"; 4680 4681 if ((fmt2 = getenv(_LD("TRACE_LOADED_OBJECTS_FMT2"))) == NULL) 4682 fmt2 = "\t%o (%x)\n"; 4683 4684 list_containers = getenv(_LD("TRACE_LOADED_OBJECTS_ALL")); 4685 4686 for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 4687 Needed_Entry *needed; 4688 const char *name, *path; 4689 bool is_lib; 4690 4691 if (obj->marker) 4692 continue; 4693 if (list_containers && obj->needed != NULL) 4694 rtld_printf("%s:\n", obj->path); 4695 for (needed = obj->needed; needed; needed = needed->next) { 4696 if (needed->obj != NULL) { 4697 if (needed->obj->traced && !list_containers) 4698 continue; 4699 needed->obj->traced = true; 4700 path = needed->obj->path; 4701 } else 4702 path = "not found"; 4703 4704 name = obj->strtab + needed->name; 4705 is_lib = strncmp(name, "lib", 3) == 0; /* XXX - bogus */ 4706 4707 fmt = is_lib ? fmt1 : fmt2; 4708 while ((c = *fmt++) != '\0') { 4709 switch (c) { 4710 default: 4711 rtld_putchar(c); 4712 continue; 4713 case '\\': 4714 switch (c = *fmt) { 4715 case '\0': 4716 continue; 4717 case 'n': 4718 rtld_putchar('\n'); 4719 break; 4720 case 't': 4721 rtld_putchar('\t'); 4722 break; 4723 } 4724 break; 4725 case '%': 4726 switch (c = *fmt) { 4727 case '\0': 4728 continue; 4729 case '%': 4730 default: 4731 rtld_putchar(c); 4732 break; 4733 case 'A': 4734 rtld_putstr(main_local); 4735 break; 4736 case 'a': 4737 rtld_putstr(obj_main->path); 4738 break; 4739 case 'o': 4740 rtld_putstr(name); 4741 break; 4742 #if 0 4743 case 'm': 4744 rtld_printf("%d", sodp->sod_major); 4745 break; 4746 case 'n': 4747 rtld_printf("%d", sodp->sod_minor); 4748 break; 4749 #endif 4750 case 'p': 4751 rtld_putstr(path); 4752 break; 4753 case 'x': 4754 rtld_printf("%p", needed->obj ? needed->obj->mapbase : 4755 0); 4756 break; 4757 } 4758 break; 4759 } 4760 ++fmt; 4761 } 4762 } 4763 } 4764 } 4765 4766 /* 4767 * Unload a dlopened object and its dependencies from memory and from 4768 * our data structures. It is assumed that the DAG rooted in the 4769 * object has already been unreferenced, and that the object has a 4770 * reference count of 0. 4771 */ 4772 static void 4773 unload_object(Obj_Entry *root, RtldLockState *lockstate) 4774 { 4775 Obj_Entry marker, *obj, *next; 4776 4777 assert(root->refcount == 0); 4778 4779 /* 4780 * Pass over the DAG removing unreferenced objects from 4781 * appropriate lists. 4782 */ 4783 unlink_object(root); 4784 4785 /* Unmap all objects that are no longer referenced. */ 4786 for (obj = TAILQ_FIRST(&obj_list); obj != NULL; obj = next) { 4787 next = TAILQ_NEXT(obj, next); 4788 if (obj->marker || obj->refcount != 0) 4789 continue; 4790 LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase, 4791 obj->mapsize, 0, obj->path); 4792 dbg("unloading \"%s\"", obj->path); 4793 /* 4794 * Unlink the object now to prevent new references from 4795 * being acquired while the bind lock is dropped in 4796 * recursive dlclose() invocations. 4797 */ 4798 TAILQ_REMOVE(&obj_list, obj, next); 4799 obj_count--; 4800 4801 if (obj->filtees_loaded) { 4802 if (next != NULL) { 4803 init_marker(&marker); 4804 TAILQ_INSERT_BEFORE(next, &marker, next); 4805 unload_filtees(obj, lockstate); 4806 next = TAILQ_NEXT(&marker, next); 4807 TAILQ_REMOVE(&obj_list, &marker, next); 4808 } else 4809 unload_filtees(obj, lockstate); 4810 } 4811 release_object(obj); 4812 } 4813 } 4814 4815 static void 4816 unlink_object(Obj_Entry *root) 4817 { 4818 Objlist_Entry *elm; 4819 4820 if (root->refcount == 0) { 4821 /* Remove the object from the RTLD_GLOBAL list. */ 4822 objlist_remove(&list_global, root); 4823 4824 /* Remove the object from all objects' DAG lists. */ 4825 STAILQ_FOREACH(elm, &root->dagmembers, link) { 4826 objlist_remove(&elm->obj->dldags, root); 4827 if (elm->obj != root) 4828 unlink_object(elm->obj); 4829 } 4830 } 4831 } 4832 4833 static void 4834 ref_dag(Obj_Entry *root) 4835 { 4836 Objlist_Entry *elm; 4837 4838 assert(root->dag_inited); 4839 STAILQ_FOREACH(elm, &root->dagmembers, link) 4840 elm->obj->refcount++; 4841 } 4842 4843 static void 4844 unref_dag(Obj_Entry *root) 4845 { 4846 Objlist_Entry *elm; 4847 4848 assert(root->dag_inited); 4849 STAILQ_FOREACH(elm, &root->dagmembers, link) 4850 elm->obj->refcount--; 4851 } 4852 4853 /* 4854 * Common code for MD __tls_get_addr(). 4855 */ 4856 static void * 4857 tls_get_addr_slow(Elf_Addr **dtvp, int index, size_t offset, bool locked) 4858 { 4859 Elf_Addr *newdtv, *dtv; 4860 RtldLockState lockstate; 4861 int to_copy; 4862 4863 dtv = *dtvp; 4864 /* Check dtv generation in case new modules have arrived */ 4865 if (dtv[0] != tls_dtv_generation) { 4866 if (!locked) 4867 wlock_acquire(rtld_bind_lock, &lockstate); 4868 newdtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4869 to_copy = dtv[1]; 4870 if (to_copy > tls_max_index) 4871 to_copy = tls_max_index; 4872 memcpy(&newdtv[2], &dtv[2], to_copy * sizeof(Elf_Addr)); 4873 newdtv[0] = tls_dtv_generation; 4874 newdtv[1] = tls_max_index; 4875 free(dtv); 4876 if (!locked) 4877 lock_release(rtld_bind_lock, &lockstate); 4878 dtv = *dtvp = newdtv; 4879 } 4880 4881 /* Dynamically allocate module TLS if necessary */ 4882 if (dtv[index + 1] == 0) { 4883 /* Signal safe, wlock will block out signals. */ 4884 if (!locked) 4885 wlock_acquire(rtld_bind_lock, &lockstate); 4886 if (!dtv[index + 1]) 4887 dtv[index + 1] = (Elf_Addr)allocate_module_tls(index); 4888 if (!locked) 4889 lock_release(rtld_bind_lock, &lockstate); 4890 } 4891 return ((void *)(dtv[index + 1] + offset)); 4892 } 4893 4894 void * 4895 tls_get_addr_common(Elf_Addr **dtvp, int index, size_t offset) 4896 { 4897 Elf_Addr *dtv; 4898 4899 dtv = *dtvp; 4900 /* Check dtv generation in case new modules have arrived */ 4901 if (__predict_true(dtv[0] == tls_dtv_generation && 4902 dtv[index + 1] != 0)) 4903 return ((void *)(dtv[index + 1] + offset)); 4904 return (tls_get_addr_slow(dtvp, index, offset, false)); 4905 } 4906 4907 #if defined(__aarch64__) || defined(__arm__) || defined(__mips__) || \ 4908 defined(__powerpc__) || defined(__riscv) 4909 4910 /* 4911 * Return pointer to allocated TLS block 4912 */ 4913 static void * 4914 get_tls_block_ptr(void *tcb, size_t tcbsize) 4915 { 4916 size_t extra_size, post_size, pre_size, tls_block_size; 4917 size_t tls_init_align; 4918 4919 tls_init_align = MAX(obj_main->tlsalign, 1); 4920 4921 /* Compute fragments sizes. */ 4922 extra_size = tcbsize - TLS_TCB_SIZE; 4923 post_size = calculate_tls_post_size(tls_init_align); 4924 tls_block_size = tcbsize + post_size; 4925 pre_size = roundup2(tls_block_size, tls_init_align) - tls_block_size; 4926 4927 return ((char *)tcb - pre_size - extra_size); 4928 } 4929 4930 /* 4931 * Allocate Static TLS using the Variant I method. 4932 * 4933 * For details on the layout, see lib/libc/gen/tls.c. 4934 * 4935 * NB: rtld's tls_static_space variable includes TLS_TCB_SIZE and post_size as 4936 * it is based on tls_last_offset, and TLS offsets here are really TCB 4937 * offsets, whereas libc's tls_static_space is just the executable's static 4938 * TLS segment. 4939 */ 4940 void * 4941 allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign) 4942 { 4943 Obj_Entry *obj; 4944 char *tls_block; 4945 Elf_Addr *dtv, **tcb; 4946 Elf_Addr addr; 4947 Elf_Addr i; 4948 size_t extra_size, maxalign, post_size, pre_size, tls_block_size; 4949 size_t tls_init_align, tls_init_offset; 4950 4951 if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE) 4952 return (oldtcb); 4953 4954 assert(tcbsize >= TLS_TCB_SIZE); 4955 maxalign = MAX(tcbalign, tls_static_max_align); 4956 tls_init_align = MAX(obj_main->tlsalign, 1); 4957 4958 /* Compute fragmets sizes. */ 4959 extra_size = tcbsize - TLS_TCB_SIZE; 4960 post_size = calculate_tls_post_size(tls_init_align); 4961 tls_block_size = tcbsize + post_size; 4962 pre_size = roundup2(tls_block_size, tls_init_align) - tls_block_size; 4963 tls_block_size += pre_size + tls_static_space - TLS_TCB_SIZE - post_size; 4964 4965 /* Allocate whole TLS block */ 4966 tls_block = malloc_aligned(tls_block_size, maxalign, 0); 4967 tcb = (Elf_Addr **)(tls_block + pre_size + extra_size); 4968 4969 if (oldtcb != NULL) { 4970 memcpy(tls_block, get_tls_block_ptr(oldtcb, tcbsize), 4971 tls_static_space); 4972 free_aligned(get_tls_block_ptr(oldtcb, tcbsize)); 4973 4974 /* Adjust the DTV. */ 4975 dtv = tcb[0]; 4976 for (i = 0; i < dtv[1]; i++) { 4977 if (dtv[i+2] >= (Elf_Addr)oldtcb && 4978 dtv[i+2] < (Elf_Addr)oldtcb + tls_static_space) { 4979 dtv[i+2] = dtv[i+2] - (Elf_Addr)oldtcb + (Elf_Addr)tcb; 4980 } 4981 } 4982 } else { 4983 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4984 tcb[0] = dtv; 4985 dtv[0] = tls_dtv_generation; 4986 dtv[1] = tls_max_index; 4987 4988 for (obj = globallist_curr(objs); obj != NULL; 4989 obj = globallist_next(obj)) { 4990 if (obj->tlsoffset == 0) 4991 continue; 4992 tls_init_offset = obj->tlspoffset & (obj->tlsalign - 1); 4993 addr = (Elf_Addr)tcb + obj->tlsoffset; 4994 if (tls_init_offset > 0) 4995 memset((void *)addr, 0, tls_init_offset); 4996 if (obj->tlsinitsize > 0) { 4997 memcpy((void *)(addr + tls_init_offset), obj->tlsinit, 4998 obj->tlsinitsize); 4999 } 5000 if (obj->tlssize > obj->tlsinitsize) { 5001 memset((void *)(addr + tls_init_offset + obj->tlsinitsize), 5002 0, obj->tlssize - obj->tlsinitsize - tls_init_offset); 5003 } 5004 dtv[obj->tlsindex + 1] = addr; 5005 } 5006 } 5007 5008 return (tcb); 5009 } 5010 5011 void 5012 free_tls(void *tcb, size_t tcbsize, size_t tcbalign __unused) 5013 { 5014 Elf_Addr *dtv; 5015 Elf_Addr tlsstart, tlsend; 5016 size_t post_size; 5017 size_t dtvsize, i, tls_init_align; 5018 5019 assert(tcbsize >= TLS_TCB_SIZE); 5020 tls_init_align = MAX(obj_main->tlsalign, 1); 5021 5022 /* Compute fragments sizes. */ 5023 post_size = calculate_tls_post_size(tls_init_align); 5024 5025 tlsstart = (Elf_Addr)tcb + TLS_TCB_SIZE + post_size; 5026 tlsend = (Elf_Addr)tcb + tls_static_space; 5027 5028 dtv = *(Elf_Addr **)tcb; 5029 dtvsize = dtv[1]; 5030 for (i = 0; i < dtvsize; i++) { 5031 if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] >= tlsend)) { 5032 free((void*)dtv[i+2]); 5033 } 5034 } 5035 free(dtv); 5036 free_aligned(get_tls_block_ptr(tcb, tcbsize)); 5037 } 5038 5039 #endif 5040 5041 #if defined(__i386__) || defined(__amd64__) 5042 5043 /* 5044 * Allocate Static TLS using the Variant II method. 5045 */ 5046 void * 5047 allocate_tls(Obj_Entry *objs, void *oldtls, size_t tcbsize, size_t tcbalign) 5048 { 5049 Obj_Entry *obj; 5050 size_t size, ralign; 5051 char *tls; 5052 Elf_Addr *dtv, *olddtv; 5053 Elf_Addr segbase, oldsegbase, addr; 5054 size_t i; 5055 5056 ralign = tcbalign; 5057 if (tls_static_max_align > ralign) 5058 ralign = tls_static_max_align; 5059 size = roundup(tls_static_space, ralign) + roundup(tcbsize, ralign); 5060 5061 assert(tcbsize >= 2*sizeof(Elf_Addr)); 5062 tls = malloc_aligned(size, ralign, 0 /* XXX */); 5063 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 5064 5065 segbase = (Elf_Addr)(tls + roundup(tls_static_space, ralign)); 5066 ((Elf_Addr*)segbase)[0] = segbase; 5067 ((Elf_Addr*)segbase)[1] = (Elf_Addr) dtv; 5068 5069 dtv[0] = tls_dtv_generation; 5070 dtv[1] = tls_max_index; 5071 5072 if (oldtls) { 5073 /* 5074 * Copy the static TLS block over whole. 5075 */ 5076 oldsegbase = (Elf_Addr) oldtls; 5077 memcpy((void *)(segbase - tls_static_space), 5078 (const void *)(oldsegbase - tls_static_space), 5079 tls_static_space); 5080 5081 /* 5082 * If any dynamic TLS blocks have been created tls_get_addr(), 5083 * move them over. 5084 */ 5085 olddtv = ((Elf_Addr**)oldsegbase)[1]; 5086 for (i = 0; i < olddtv[1]; i++) { 5087 if (olddtv[i+2] < oldsegbase - size || olddtv[i+2] > oldsegbase) { 5088 dtv[i+2] = olddtv[i+2]; 5089 olddtv[i+2] = 0; 5090 } 5091 } 5092 5093 /* 5094 * We assume that this block was the one we created with 5095 * allocate_initial_tls(). 5096 */ 5097 free_tls(oldtls, 2*sizeof(Elf_Addr), sizeof(Elf_Addr)); 5098 } else { 5099 for (obj = objs; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 5100 if (obj->marker || obj->tlsoffset == 0) 5101 continue; 5102 addr = segbase - obj->tlsoffset; 5103 memset((void*)(addr + obj->tlsinitsize), 5104 0, obj->tlssize - obj->tlsinitsize); 5105 if (obj->tlsinit) { 5106 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize); 5107 obj->static_tls_copied = true; 5108 } 5109 dtv[obj->tlsindex + 1] = addr; 5110 } 5111 } 5112 5113 return (void*) segbase; 5114 } 5115 5116 void 5117 free_tls(void *tls, size_t tcbsize __unused, size_t tcbalign) 5118 { 5119 Elf_Addr* dtv; 5120 size_t size, ralign; 5121 int dtvsize, i; 5122 Elf_Addr tlsstart, tlsend; 5123 5124 /* 5125 * Figure out the size of the initial TLS block so that we can 5126 * find stuff which ___tls_get_addr() allocated dynamically. 5127 */ 5128 ralign = tcbalign; 5129 if (tls_static_max_align > ralign) 5130 ralign = tls_static_max_align; 5131 size = roundup(tls_static_space, ralign); 5132 5133 dtv = ((Elf_Addr**)tls)[1]; 5134 dtvsize = dtv[1]; 5135 tlsend = (Elf_Addr) tls; 5136 tlsstart = tlsend - size; 5137 for (i = 0; i < dtvsize; i++) { 5138 if (dtv[i + 2] != 0 && (dtv[i + 2] < tlsstart || dtv[i + 2] > tlsend)) { 5139 free_aligned((void *)dtv[i + 2]); 5140 } 5141 } 5142 5143 free_aligned((void *)tlsstart); 5144 free((void*) dtv); 5145 } 5146 5147 #endif 5148 5149 /* 5150 * Allocate TLS block for module with given index. 5151 */ 5152 void * 5153 allocate_module_tls(int index) 5154 { 5155 Obj_Entry *obj; 5156 char *p; 5157 5158 TAILQ_FOREACH(obj, &obj_list, next) { 5159 if (obj->marker) 5160 continue; 5161 if (obj->tlsindex == index) 5162 break; 5163 } 5164 if (obj == NULL) { 5165 _rtld_error("Can't find module with TLS index %d", index); 5166 rtld_die(); 5167 } 5168 5169 p = malloc_aligned(obj->tlssize, obj->tlsalign, obj->tlspoffset); 5170 memcpy(p, obj->tlsinit, obj->tlsinitsize); 5171 memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize); 5172 return (p); 5173 } 5174 5175 bool 5176 allocate_tls_offset(Obj_Entry *obj) 5177 { 5178 size_t off; 5179 5180 if (obj->tls_done) 5181 return true; 5182 5183 if (obj->tlssize == 0) { 5184 obj->tls_done = true; 5185 return true; 5186 } 5187 5188 if (tls_last_offset == 0) 5189 off = calculate_first_tls_offset(obj->tlssize, obj->tlsalign, 5190 obj->tlspoffset); 5191 else 5192 off = calculate_tls_offset(tls_last_offset, tls_last_size, 5193 obj->tlssize, obj->tlsalign, obj->tlspoffset); 5194 5195 /* 5196 * If we have already fixed the size of the static TLS block, we 5197 * must stay within that size. When allocating the static TLS, we 5198 * leave a small amount of space spare to be used for dynamically 5199 * loading modules which use static TLS. 5200 */ 5201 if (tls_static_space != 0) { 5202 if (calculate_tls_end(off, obj->tlssize) > tls_static_space) 5203 return false; 5204 } else if (obj->tlsalign > tls_static_max_align) { 5205 tls_static_max_align = obj->tlsalign; 5206 } 5207 5208 tls_last_offset = obj->tlsoffset = off; 5209 tls_last_size = obj->tlssize; 5210 obj->tls_done = true; 5211 5212 return true; 5213 } 5214 5215 void 5216 free_tls_offset(Obj_Entry *obj) 5217 { 5218 5219 /* 5220 * If we were the last thing to allocate out of the static TLS 5221 * block, we give our space back to the 'allocator'. This is a 5222 * simplistic workaround to allow libGL.so.1 to be loaded and 5223 * unloaded multiple times. 5224 */ 5225 if (calculate_tls_end(obj->tlsoffset, obj->tlssize) 5226 == calculate_tls_end(tls_last_offset, tls_last_size)) { 5227 tls_last_offset -= obj->tlssize; 5228 tls_last_size = 0; 5229 } 5230 } 5231 5232 void * 5233 _rtld_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign) 5234 { 5235 void *ret; 5236 RtldLockState lockstate; 5237 5238 wlock_acquire(rtld_bind_lock, &lockstate); 5239 ret = allocate_tls(globallist_curr(TAILQ_FIRST(&obj_list)), oldtls, 5240 tcbsize, tcbalign); 5241 lock_release(rtld_bind_lock, &lockstate); 5242 return (ret); 5243 } 5244 5245 void 5246 _rtld_free_tls(void *tcb, size_t tcbsize, size_t tcbalign) 5247 { 5248 RtldLockState lockstate; 5249 5250 wlock_acquire(rtld_bind_lock, &lockstate); 5251 free_tls(tcb, tcbsize, tcbalign); 5252 lock_release(rtld_bind_lock, &lockstate); 5253 } 5254 5255 static void 5256 object_add_name(Obj_Entry *obj, const char *name) 5257 { 5258 Name_Entry *entry; 5259 size_t len; 5260 5261 len = strlen(name); 5262 entry = malloc(sizeof(Name_Entry) + len); 5263 5264 if (entry != NULL) { 5265 strcpy(entry->name, name); 5266 STAILQ_INSERT_TAIL(&obj->names, entry, link); 5267 } 5268 } 5269 5270 static int 5271 object_match_name(const Obj_Entry *obj, const char *name) 5272 { 5273 Name_Entry *entry; 5274 5275 STAILQ_FOREACH(entry, &obj->names, link) { 5276 if (strcmp(name, entry->name) == 0) 5277 return (1); 5278 } 5279 return (0); 5280 } 5281 5282 static Obj_Entry * 5283 locate_dependency(const Obj_Entry *obj, const char *name) 5284 { 5285 const Objlist_Entry *entry; 5286 const Needed_Entry *needed; 5287 5288 STAILQ_FOREACH(entry, &list_main, link) { 5289 if (object_match_name(entry->obj, name)) 5290 return entry->obj; 5291 } 5292 5293 for (needed = obj->needed; needed != NULL; needed = needed->next) { 5294 if (strcmp(obj->strtab + needed->name, name) == 0 || 5295 (needed->obj != NULL && object_match_name(needed->obj, name))) { 5296 /* 5297 * If there is DT_NEEDED for the name we are looking for, 5298 * we are all set. Note that object might not be found if 5299 * dependency was not loaded yet, so the function can 5300 * return NULL here. This is expected and handled 5301 * properly by the caller. 5302 */ 5303 return (needed->obj); 5304 } 5305 } 5306 _rtld_error("%s: Unexpected inconsistency: dependency %s not found", 5307 obj->path, name); 5308 rtld_die(); 5309 } 5310 5311 static int 5312 check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj, 5313 const Elf_Vernaux *vna) 5314 { 5315 const Elf_Verdef *vd; 5316 const char *vername; 5317 5318 vername = refobj->strtab + vna->vna_name; 5319 vd = depobj->verdef; 5320 if (vd == NULL) { 5321 _rtld_error("%s: version %s required by %s not defined", 5322 depobj->path, vername, refobj->path); 5323 return (-1); 5324 } 5325 for (;;) { 5326 if (vd->vd_version != VER_DEF_CURRENT) { 5327 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 5328 depobj->path, vd->vd_version); 5329 return (-1); 5330 } 5331 if (vna->vna_hash == vd->vd_hash) { 5332 const Elf_Verdaux *aux = (const Elf_Verdaux *) 5333 ((const char *)vd + vd->vd_aux); 5334 if (strcmp(vername, depobj->strtab + aux->vda_name) == 0) 5335 return (0); 5336 } 5337 if (vd->vd_next == 0) 5338 break; 5339 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 5340 } 5341 if (vna->vna_flags & VER_FLG_WEAK) 5342 return (0); 5343 _rtld_error("%s: version %s required by %s not found", 5344 depobj->path, vername, refobj->path); 5345 return (-1); 5346 } 5347 5348 static int 5349 rtld_verify_object_versions(Obj_Entry *obj) 5350 { 5351 const Elf_Verneed *vn; 5352 const Elf_Verdef *vd; 5353 const Elf_Verdaux *vda; 5354 const Elf_Vernaux *vna; 5355 const Obj_Entry *depobj; 5356 int maxvernum, vernum; 5357 5358 if (obj->ver_checked) 5359 return (0); 5360 obj->ver_checked = true; 5361 5362 maxvernum = 0; 5363 /* 5364 * Walk over defined and required version records and figure out 5365 * max index used by any of them. Do very basic sanity checking 5366 * while there. 5367 */ 5368 vn = obj->verneed; 5369 while (vn != NULL) { 5370 if (vn->vn_version != VER_NEED_CURRENT) { 5371 _rtld_error("%s: Unsupported version %d of Elf_Verneed entry", 5372 obj->path, vn->vn_version); 5373 return (-1); 5374 } 5375 vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux); 5376 for (;;) { 5377 vernum = VER_NEED_IDX(vna->vna_other); 5378 if (vernum > maxvernum) 5379 maxvernum = vernum; 5380 if (vna->vna_next == 0) 5381 break; 5382 vna = (const Elf_Vernaux *)((const char *)vna + vna->vna_next); 5383 } 5384 if (vn->vn_next == 0) 5385 break; 5386 vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next); 5387 } 5388 5389 vd = obj->verdef; 5390 while (vd != NULL) { 5391 if (vd->vd_version != VER_DEF_CURRENT) { 5392 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 5393 obj->path, vd->vd_version); 5394 return (-1); 5395 } 5396 vernum = VER_DEF_IDX(vd->vd_ndx); 5397 if (vernum > maxvernum) 5398 maxvernum = vernum; 5399 if (vd->vd_next == 0) 5400 break; 5401 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 5402 } 5403 5404 if (maxvernum == 0) 5405 return (0); 5406 5407 /* 5408 * Store version information in array indexable by version index. 5409 * Verify that object version requirements are satisfied along the 5410 * way. 5411 */ 5412 obj->vernum = maxvernum + 1; 5413 obj->vertab = xcalloc(obj->vernum, sizeof(Ver_Entry)); 5414 5415 vd = obj->verdef; 5416 while (vd != NULL) { 5417 if ((vd->vd_flags & VER_FLG_BASE) == 0) { 5418 vernum = VER_DEF_IDX(vd->vd_ndx); 5419 assert(vernum <= maxvernum); 5420 vda = (const Elf_Verdaux *)((const char *)vd + vd->vd_aux); 5421 obj->vertab[vernum].hash = vd->vd_hash; 5422 obj->vertab[vernum].name = obj->strtab + vda->vda_name; 5423 obj->vertab[vernum].file = NULL; 5424 obj->vertab[vernum].flags = 0; 5425 } 5426 if (vd->vd_next == 0) 5427 break; 5428 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 5429 } 5430 5431 vn = obj->verneed; 5432 while (vn != NULL) { 5433 depobj = locate_dependency(obj, obj->strtab + vn->vn_file); 5434 if (depobj == NULL) 5435 return (-1); 5436 vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux); 5437 for (;;) { 5438 if (check_object_provided_version(obj, depobj, vna)) 5439 return (-1); 5440 vernum = VER_NEED_IDX(vna->vna_other); 5441 assert(vernum <= maxvernum); 5442 obj->vertab[vernum].hash = vna->vna_hash; 5443 obj->vertab[vernum].name = obj->strtab + vna->vna_name; 5444 obj->vertab[vernum].file = obj->strtab + vn->vn_file; 5445 obj->vertab[vernum].flags = (vna->vna_other & VER_NEED_HIDDEN) ? 5446 VER_INFO_HIDDEN : 0; 5447 if (vna->vna_next == 0) 5448 break; 5449 vna = (const Elf_Vernaux *)((const char *)vna + vna->vna_next); 5450 } 5451 if (vn->vn_next == 0) 5452 break; 5453 vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next); 5454 } 5455 return 0; 5456 } 5457 5458 static int 5459 rtld_verify_versions(const Objlist *objlist) 5460 { 5461 Objlist_Entry *entry; 5462 int rc; 5463 5464 rc = 0; 5465 STAILQ_FOREACH(entry, objlist, link) { 5466 /* 5467 * Skip dummy objects or objects that have their version requirements 5468 * already checked. 5469 */ 5470 if (entry->obj->strtab == NULL || entry->obj->vertab != NULL) 5471 continue; 5472 if (rtld_verify_object_versions(entry->obj) == -1) { 5473 rc = -1; 5474 if (ld_tracing == NULL) 5475 break; 5476 } 5477 } 5478 if (rc == 0 || ld_tracing != NULL) 5479 rc = rtld_verify_object_versions(&obj_rtld); 5480 return rc; 5481 } 5482 5483 const Ver_Entry * 5484 fetch_ventry(const Obj_Entry *obj, unsigned long symnum) 5485 { 5486 Elf_Versym vernum; 5487 5488 if (obj->vertab) { 5489 vernum = VER_NDX(obj->versyms[symnum]); 5490 if (vernum >= obj->vernum) { 5491 _rtld_error("%s: symbol %s has wrong verneed value %d", 5492 obj->path, obj->strtab + symnum, vernum); 5493 } else if (obj->vertab[vernum].hash != 0) { 5494 return &obj->vertab[vernum]; 5495 } 5496 } 5497 return NULL; 5498 } 5499 5500 int 5501 _rtld_get_stack_prot(void) 5502 { 5503 5504 return (stack_prot); 5505 } 5506 5507 int 5508 _rtld_is_dlopened(void *arg) 5509 { 5510 Obj_Entry *obj; 5511 RtldLockState lockstate; 5512 int res; 5513 5514 rlock_acquire(rtld_bind_lock, &lockstate); 5515 obj = dlcheck(arg); 5516 if (obj == NULL) 5517 obj = obj_from_addr(arg); 5518 if (obj == NULL) { 5519 _rtld_error("No shared object contains address"); 5520 lock_release(rtld_bind_lock, &lockstate); 5521 return (-1); 5522 } 5523 res = obj->dlopened ? 1 : 0; 5524 lock_release(rtld_bind_lock, &lockstate); 5525 return (res); 5526 } 5527 5528 static int 5529 obj_remap_relro(Obj_Entry *obj, int prot) 5530 { 5531 5532 if (obj->relro_size > 0 && mprotect(obj->relro_page, obj->relro_size, 5533 prot) == -1) { 5534 _rtld_error("%s: Cannot set relro protection to %#x: %s", 5535 obj->path, prot, rtld_strerror(errno)); 5536 return (-1); 5537 } 5538 return (0); 5539 } 5540 5541 static int 5542 obj_disable_relro(Obj_Entry *obj) 5543 { 5544 5545 return (obj_remap_relro(obj, PROT_READ | PROT_WRITE)); 5546 } 5547 5548 static int 5549 obj_enforce_relro(Obj_Entry *obj) 5550 { 5551 5552 return (obj_remap_relro(obj, PROT_READ)); 5553 } 5554 5555 static void 5556 map_stacks_exec(RtldLockState *lockstate) 5557 { 5558 void (*thr_map_stacks_exec)(void); 5559 5560 if ((max_stack_flags & PF_X) == 0 || (stack_prot & PROT_EXEC) != 0) 5561 return; 5562 thr_map_stacks_exec = (void (*)(void))(uintptr_t) 5563 get_program_var_addr("__pthread_map_stacks_exec", lockstate); 5564 if (thr_map_stacks_exec != NULL) { 5565 stack_prot |= PROT_EXEC; 5566 thr_map_stacks_exec(); 5567 } 5568 } 5569 5570 static void 5571 distribute_static_tls(Objlist *list, RtldLockState *lockstate) 5572 { 5573 Objlist_Entry *elm; 5574 Obj_Entry *obj; 5575 void (*distrib)(size_t, void *, size_t, size_t); 5576 5577 distrib = (void (*)(size_t, void *, size_t, size_t))(uintptr_t) 5578 get_program_var_addr("__pthread_distribute_static_tls", lockstate); 5579 if (distrib == NULL) 5580 return; 5581 STAILQ_FOREACH(elm, list, link) { 5582 obj = elm->obj; 5583 if (obj->marker || !obj->tls_done || obj->static_tls_copied) 5584 continue; 5585 distrib(obj->tlsoffset, obj->tlsinit, obj->tlsinitsize, 5586 obj->tlssize); 5587 obj->static_tls_copied = true; 5588 } 5589 } 5590 5591 void 5592 symlook_init(SymLook *dst, const char *name) 5593 { 5594 5595 bzero(dst, sizeof(*dst)); 5596 dst->name = name; 5597 dst->hash = elf_hash(name); 5598 dst->hash_gnu = gnu_hash(name); 5599 } 5600 5601 static void 5602 symlook_init_from_req(SymLook *dst, const SymLook *src) 5603 { 5604 5605 dst->name = src->name; 5606 dst->hash = src->hash; 5607 dst->hash_gnu = src->hash_gnu; 5608 dst->ventry = src->ventry; 5609 dst->flags = src->flags; 5610 dst->defobj_out = NULL; 5611 dst->sym_out = NULL; 5612 dst->lockstate = src->lockstate; 5613 } 5614 5615 static int 5616 open_binary_fd(const char *argv0, bool search_in_path, 5617 const char **binpath_res) 5618 { 5619 char *binpath, *pathenv, *pe, *res1; 5620 const char *res; 5621 int fd; 5622 5623 binpath = NULL; 5624 res = NULL; 5625 if (search_in_path && strchr(argv0, '/') == NULL) { 5626 binpath = xmalloc(PATH_MAX); 5627 pathenv = getenv("PATH"); 5628 if (pathenv == NULL) { 5629 _rtld_error("-p and no PATH environment variable"); 5630 rtld_die(); 5631 } 5632 pathenv = strdup(pathenv); 5633 if (pathenv == NULL) { 5634 _rtld_error("Cannot allocate memory"); 5635 rtld_die(); 5636 } 5637 fd = -1; 5638 errno = ENOENT; 5639 while ((pe = strsep(&pathenv, ":")) != NULL) { 5640 if (strlcpy(binpath, pe, PATH_MAX) >= PATH_MAX) 5641 continue; 5642 if (binpath[0] != '\0' && 5643 strlcat(binpath, "/", PATH_MAX) >= PATH_MAX) 5644 continue; 5645 if (strlcat(binpath, argv0, PATH_MAX) >= PATH_MAX) 5646 continue; 5647 fd = open(binpath, O_RDONLY | O_CLOEXEC | O_VERIFY); 5648 if (fd != -1 || errno != ENOENT) { 5649 res = binpath; 5650 break; 5651 } 5652 } 5653 free(pathenv); 5654 } else { 5655 fd = open(argv0, O_RDONLY | O_CLOEXEC | O_VERIFY); 5656 res = argv0; 5657 } 5658 5659 if (fd == -1) { 5660 _rtld_error("Cannot open %s: %s", argv0, rtld_strerror(errno)); 5661 rtld_die(); 5662 } 5663 if (res != NULL && res[0] != '/') { 5664 res1 = xmalloc(PATH_MAX); 5665 if (realpath(res, res1) != NULL) { 5666 if (res != argv0) 5667 free(__DECONST(char *, res)); 5668 res = res1; 5669 } else { 5670 free(res1); 5671 } 5672 } 5673 *binpath_res = res; 5674 return (fd); 5675 } 5676 5677 /* 5678 * Parse a set of command-line arguments. 5679 */ 5680 static int 5681 parse_args(char* argv[], int argc, bool *use_pathp, int *fdp, 5682 const char **argv0) 5683 { 5684 const char *arg; 5685 char machine[64]; 5686 size_t sz; 5687 int arglen, fd, i, j, mib[2]; 5688 char opt; 5689 bool seen_b, seen_f; 5690 5691 dbg("Parsing command-line arguments"); 5692 *use_pathp = false; 5693 *fdp = -1; 5694 seen_b = seen_f = false; 5695 5696 for (i = 1; i < argc; i++ ) { 5697 arg = argv[i]; 5698 dbg("argv[%d]: '%s'", i, arg); 5699 5700 /* 5701 * rtld arguments end with an explicit "--" or with the first 5702 * non-prefixed argument. 5703 */ 5704 if (strcmp(arg, "--") == 0) { 5705 i++; 5706 break; 5707 } 5708 if (arg[0] != '-') 5709 break; 5710 5711 /* 5712 * All other arguments are single-character options that can 5713 * be combined, so we need to search through `arg` for them. 5714 */ 5715 arglen = strlen(arg); 5716 for (j = 1; j < arglen; j++) { 5717 opt = arg[j]; 5718 if (opt == 'h') { 5719 print_usage(argv[0]); 5720 _exit(0); 5721 } else if (opt == 'b') { 5722 if (seen_f) { 5723 _rtld_error("Both -b and -f specified"); 5724 rtld_die(); 5725 } 5726 i++; 5727 *argv0 = argv[i]; 5728 seen_b = true; 5729 break; 5730 } else if (opt == 'f') { 5731 if (seen_b) { 5732 _rtld_error("Both -b and -f specified"); 5733 rtld_die(); 5734 } 5735 5736 /* 5737 * -f XX can be used to specify a 5738 * descriptor for the binary named at 5739 * the command line (i.e., the later 5740 * argument will specify the process 5741 * name but the descriptor is what 5742 * will actually be executed). 5743 * 5744 * -f must be the last option in, e.g., -abcf. 5745 */ 5746 if (j != arglen - 1) { 5747 _rtld_error("Invalid options: %s", arg); 5748 rtld_die(); 5749 } 5750 i++; 5751 fd = parse_integer(argv[i]); 5752 if (fd == -1) { 5753 _rtld_error( 5754 "Invalid file descriptor: '%s'", 5755 argv[i]); 5756 rtld_die(); 5757 } 5758 *fdp = fd; 5759 seen_f = true; 5760 break; 5761 } else if (opt == 'p') { 5762 *use_pathp = true; 5763 } else if (opt == 'v') { 5764 machine[0] = '\0'; 5765 mib[0] = CTL_HW; 5766 mib[1] = HW_MACHINE; 5767 sz = sizeof(machine); 5768 sysctl(mib, nitems(mib), machine, &sz, NULL, 0); 5769 rtld_printf( 5770 "FreeBSD ld-elf.so.1 %s\n" 5771 "FreeBSD_version %d\n" 5772 "Default lib path %s\n" 5773 "Env prefix %s\n" 5774 "Hint file %s\n" 5775 "libmap file %s\n", 5776 machine, 5777 __FreeBSD_version, ld_standard_library_path, 5778 ld_env_prefix, ld_elf_hints_default, 5779 ld_path_libmap_conf); 5780 _exit(0); 5781 } else { 5782 _rtld_error("Invalid argument: '%s'", arg); 5783 print_usage(argv[0]); 5784 rtld_die(); 5785 } 5786 } 5787 } 5788 5789 if (!seen_b) 5790 *argv0 = argv[i]; 5791 return (i); 5792 } 5793 5794 /* 5795 * Parse a file descriptor number without pulling in more of libc (e.g. atoi). 5796 */ 5797 static int 5798 parse_integer(const char *str) 5799 { 5800 static const int RADIX = 10; /* XXXJA: possibly support hex? */ 5801 const char *orig; 5802 int n; 5803 char c; 5804 5805 orig = str; 5806 n = 0; 5807 for (c = *str; c != '\0'; c = *++str) { 5808 if (c < '0' || c > '9') 5809 return (-1); 5810 5811 n *= RADIX; 5812 n += c - '0'; 5813 } 5814 5815 /* Make sure we actually parsed something. */ 5816 if (str == orig) 5817 return (-1); 5818 return (n); 5819 } 5820 5821 static void 5822 print_usage(const char *argv0) 5823 { 5824 5825 rtld_printf( 5826 "Usage: %s [-h] [-b <exe>] [-f <FD>] [-p] [--] <binary> [<args>]\n" 5827 "\n" 5828 "Options:\n" 5829 " -h Display this help message\n" 5830 " -b <exe> Execute <exe> instead of <binary>, arg0 is <binary>\n" 5831 " -f <FD> Execute <FD> instead of searching for <binary>\n" 5832 " -p Search in PATH for named binary\n" 5833 " -v Display identification information\n" 5834 " -- End of RTLD options\n" 5835 " <binary> Name of process to execute\n" 5836 " <args> Arguments to the executed process\n", argv0); 5837 } 5838 5839 /* 5840 * Overrides for libc_pic-provided functions. 5841 */ 5842 5843 int 5844 __getosreldate(void) 5845 { 5846 size_t len; 5847 int oid[2]; 5848 int error, osrel; 5849 5850 if (osreldate != 0) 5851 return (osreldate); 5852 5853 oid[0] = CTL_KERN; 5854 oid[1] = KERN_OSRELDATE; 5855 osrel = 0; 5856 len = sizeof(osrel); 5857 error = sysctl(oid, 2, &osrel, &len, NULL, 0); 5858 if (error == 0 && osrel > 0 && len == sizeof(osrel)) 5859 osreldate = osrel; 5860 return (osreldate); 5861 } 5862 const char * 5863 rtld_strerror(int errnum) 5864 { 5865 5866 if (errnum < 0 || errnum >= sys_nerr) 5867 return ("Unknown error"); 5868 return (sys_errlist[errnum]); 5869 } 5870 5871 /* malloc */ 5872 void * 5873 malloc(size_t nbytes) 5874 { 5875 5876 return (__crt_malloc(nbytes)); 5877 } 5878 5879 void * 5880 calloc(size_t num, size_t size) 5881 { 5882 5883 return (__crt_calloc(num, size)); 5884 } 5885 5886 void 5887 free(void *cp) 5888 { 5889 5890 __crt_free(cp); 5891 } 5892 5893 void * 5894 realloc(void *cp, size_t nbytes) 5895 { 5896 5897 return (__crt_realloc(cp, nbytes)); 5898 } 5899 5900 extern int _rtld_version__FreeBSD_version __exported; 5901 int _rtld_version__FreeBSD_version = __FreeBSD_version; 5902 5903 extern char _rtld_version_laddr_offset __exported; 5904 char _rtld_version_laddr_offset; 5905 5906 extern char _rtld_version_dlpi_tls_data __exported; 5907 char _rtld_version_dlpi_tls_data; 5908