1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright 1996, 1997, 1998, 1999, 2000 John D. Polstra. 5 * Copyright 2003 Alexander Kabaev <kan@FreeBSD.ORG>. 6 * Copyright 2009-2013 Konstantin Belousov <kib@FreeBSD.ORG>. 7 * Copyright 2012 John Marino <draco@marino.st>. 8 * Copyright 2014-2017 The FreeBSD Foundation 9 * All rights reserved. 10 * 11 * Portions of this software were developed by Konstantin Belousov 12 * under sponsorship from the FreeBSD Foundation. 13 * 14 * Redistribution and use in source and binary forms, with or without 15 * modification, are permitted provided that the following conditions 16 * are met: 17 * 1. Redistributions of source code must retain the above copyright 18 * notice, this list of conditions and the following disclaimer. 19 * 2. Redistributions in binary form must reproduce the above copyright 20 * notice, this list of conditions and the following disclaimer in the 21 * documentation and/or other materials provided with the distribution. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 24 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 25 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 26 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 27 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 28 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 29 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 30 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 31 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 32 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 33 */ 34 35 /* 36 * Dynamic linker for ELF. 37 * 38 * John Polstra <jdp@polstra.com>. 39 */ 40 41 #include <sys/cdefs.h> 42 __FBSDID("$FreeBSD$"); 43 44 #include <sys/param.h> 45 #include <sys/mount.h> 46 #include <sys/mman.h> 47 #include <sys/stat.h> 48 #include <sys/sysctl.h> 49 #include <sys/uio.h> 50 #include <sys/utsname.h> 51 #include <sys/ktrace.h> 52 53 #include <dlfcn.h> 54 #include <err.h> 55 #include <errno.h> 56 #include <fcntl.h> 57 #include <stdarg.h> 58 #include <stdio.h> 59 #include <stdlib.h> 60 #include <string.h> 61 #include <unistd.h> 62 63 #include "debug.h" 64 #include "rtld.h" 65 #include "libmap.h" 66 #include "paths.h" 67 #include "rtld_tls.h" 68 #include "rtld_printf.h" 69 #include "rtld_malloc.h" 70 #include "rtld_utrace.h" 71 #include "notes.h" 72 #include "rtld_libc.h" 73 74 /* Types. */ 75 typedef void (*func_ptr_type)(void); 76 typedef void * (*path_enum_proc) (const char *path, size_t len, void *arg); 77 78 79 /* Variables that cannot be static: */ 80 extern struct r_debug r_debug; /* For GDB */ 81 extern int _thread_autoinit_dummy_decl; 82 extern void (*__cleanup)(void); 83 84 struct dlerror_save { 85 int seen; 86 char *msg; 87 }; 88 89 /* 90 * Function declarations. 91 */ 92 static const char *basename(const char *); 93 static void digest_dynamic1(Obj_Entry *, int, const Elf_Dyn **, 94 const Elf_Dyn **, const Elf_Dyn **); 95 static bool digest_dynamic2(Obj_Entry *, const Elf_Dyn *, const Elf_Dyn *, 96 const Elf_Dyn *); 97 static bool digest_dynamic(Obj_Entry *, int); 98 static Obj_Entry *digest_phdr(const Elf_Phdr *, int, caddr_t, const char *); 99 static void distribute_static_tls(Objlist *, RtldLockState *); 100 static Obj_Entry *dlcheck(void *); 101 static int dlclose_locked(void *, RtldLockState *); 102 static Obj_Entry *dlopen_object(const char *name, int fd, Obj_Entry *refobj, 103 int lo_flags, int mode, RtldLockState *lockstate); 104 static Obj_Entry *do_load_object(int, const char *, char *, struct stat *, int); 105 static int do_search_info(const Obj_Entry *obj, int, struct dl_serinfo *); 106 static bool donelist_check(DoneList *, const Obj_Entry *); 107 static void errmsg_restore(struct dlerror_save *); 108 static struct dlerror_save *errmsg_save(void); 109 static void *fill_search_info(const char *, size_t, void *); 110 static char *find_library(const char *, const Obj_Entry *, int *); 111 static const char *gethints(bool); 112 static void hold_object(Obj_Entry *); 113 static void unhold_object(Obj_Entry *); 114 static void init_dag(Obj_Entry *); 115 static void init_marker(Obj_Entry *); 116 static void init_pagesizes(Elf_Auxinfo **aux_info); 117 static void init_rtld(caddr_t, Elf_Auxinfo **); 118 static void initlist_add_neededs(Needed_Entry *, Objlist *); 119 static void initlist_add_objects(Obj_Entry *, Obj_Entry *, Objlist *); 120 static int initlist_objects_ifunc(Objlist *, bool, int, RtldLockState *); 121 static void linkmap_add(Obj_Entry *); 122 static void linkmap_delete(Obj_Entry *); 123 static void load_filtees(Obj_Entry *, int flags, RtldLockState *); 124 static void unload_filtees(Obj_Entry *, RtldLockState *); 125 static int load_needed_objects(Obj_Entry *, int); 126 static int load_preload_objects(char *, bool); 127 static Obj_Entry *load_object(const char *, int fd, const Obj_Entry *, int); 128 static void map_stacks_exec(RtldLockState *); 129 static int obj_disable_relro(Obj_Entry *); 130 static int obj_enforce_relro(Obj_Entry *); 131 static void objlist_call_fini(Objlist *, Obj_Entry *, RtldLockState *); 132 static void objlist_call_init(Objlist *, RtldLockState *); 133 static void objlist_clear(Objlist *); 134 static Objlist_Entry *objlist_find(Objlist *, const Obj_Entry *); 135 static void objlist_init(Objlist *); 136 static void objlist_push_head(Objlist *, Obj_Entry *); 137 static void objlist_push_tail(Objlist *, Obj_Entry *); 138 static void objlist_put_after(Objlist *, Obj_Entry *, Obj_Entry *); 139 static void objlist_remove(Objlist *, Obj_Entry *); 140 static int open_binary_fd(const char *argv0, bool search_in_path, 141 const char **binpath_res); 142 static int parse_args(char* argv[], int argc, bool *use_pathp, int *fdp, 143 const char **argv0); 144 static int parse_integer(const char *); 145 static void *path_enumerate(const char *, path_enum_proc, const char *, void *); 146 static void print_usage(const char *argv0); 147 static void release_object(Obj_Entry *); 148 static int relocate_object_dag(Obj_Entry *root, bool bind_now, 149 Obj_Entry *rtldobj, int flags, RtldLockState *lockstate); 150 static int relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, 151 int flags, RtldLockState *lockstate); 152 static int relocate_objects(Obj_Entry *, bool, Obj_Entry *, int, 153 RtldLockState *); 154 static int resolve_object_ifunc(Obj_Entry *, bool, int, RtldLockState *); 155 static int rtld_dirname(const char *, char *); 156 static int rtld_dirname_abs(const char *, char *); 157 static void *rtld_dlopen(const char *name, int fd, int mode); 158 static void rtld_exit(void); 159 static void rtld_nop_exit(void); 160 static char *search_library_path(const char *, const char *, const char *, 161 int *); 162 static char *search_library_pathfds(const char *, const char *, int *); 163 static const void **get_program_var_addr(const char *, RtldLockState *); 164 static void set_program_var(const char *, const void *); 165 static int symlook_default(SymLook *, const Obj_Entry *refobj); 166 static int symlook_global(SymLook *, DoneList *); 167 static void symlook_init_from_req(SymLook *, const SymLook *); 168 static int symlook_list(SymLook *, const Objlist *, DoneList *); 169 static int symlook_needed(SymLook *, const Needed_Entry *, DoneList *); 170 static int symlook_obj1_sysv(SymLook *, const Obj_Entry *); 171 static int symlook_obj1_gnu(SymLook *, const Obj_Entry *); 172 static void *tls_get_addr_slow(Elf_Addr **, int, size_t, bool) __noinline; 173 static void trace_loaded_objects(Obj_Entry *); 174 static void unlink_object(Obj_Entry *); 175 static void unload_object(Obj_Entry *, RtldLockState *lockstate); 176 static void unref_dag(Obj_Entry *); 177 static void ref_dag(Obj_Entry *); 178 static char *origin_subst_one(Obj_Entry *, char *, const char *, 179 const char *, bool); 180 static char *origin_subst(Obj_Entry *, const char *); 181 static bool obj_resolve_origin(Obj_Entry *obj); 182 static void preinit_main(void); 183 static int rtld_verify_versions(const Objlist *); 184 static int rtld_verify_object_versions(Obj_Entry *); 185 static void object_add_name(Obj_Entry *, const char *); 186 static int object_match_name(const Obj_Entry *, const char *); 187 static void ld_utrace_log(int, void *, void *, size_t, int, const char *); 188 static void rtld_fill_dl_phdr_info(const Obj_Entry *obj, 189 struct dl_phdr_info *phdr_info); 190 static uint32_t gnu_hash(const char *); 191 static bool matched_symbol(SymLook *, const Obj_Entry *, Sym_Match_Result *, 192 const unsigned long); 193 194 void r_debug_state(struct r_debug *, struct link_map *) __noinline __exported; 195 void _r_debug_postinit(struct link_map *) __noinline __exported; 196 197 int __sys_openat(int, const char *, int, ...); 198 199 /* 200 * Data declarations. 201 */ 202 struct r_debug r_debug __exported; /* for GDB; */ 203 static bool libmap_disable; /* Disable libmap */ 204 static bool ld_loadfltr; /* Immediate filters processing */ 205 static char *libmap_override; /* Maps to use in addition to libmap.conf */ 206 static bool trust; /* False for setuid and setgid programs */ 207 static bool dangerous_ld_env; /* True if environment variables have been 208 used to affect the libraries loaded */ 209 bool ld_bind_not; /* Disable PLT update */ 210 static char *ld_bind_now; /* Environment variable for immediate binding */ 211 static char *ld_debug; /* Environment variable for debugging */ 212 static bool ld_dynamic_weak = true; /* True if non-weak definition overrides 213 weak definition */ 214 static char *ld_library_path; /* Environment variable for search path */ 215 static char *ld_library_dirs; /* Environment variable for library descriptors */ 216 static char *ld_preload; /* Environment variable for libraries to 217 load first */ 218 static char *ld_preload_fds; /* Environment variable for libraries represented by 219 descriptors */ 220 static const char *ld_elf_hints_path; /* Environment variable for alternative hints path */ 221 static const char *ld_tracing; /* Called from ldd to print libs */ 222 static char *ld_utrace; /* Use utrace() to log events. */ 223 static struct obj_entry_q obj_list; /* Queue of all loaded objects */ 224 static Obj_Entry *obj_main; /* The main program shared object */ 225 static Obj_Entry obj_rtld; /* The dynamic linker shared object */ 226 static unsigned int obj_count; /* Number of objects in obj_list */ 227 static unsigned int obj_loads; /* Number of loads of objects (gen count) */ 228 229 static Objlist list_global = /* Objects dlopened with RTLD_GLOBAL */ 230 STAILQ_HEAD_INITIALIZER(list_global); 231 static Objlist list_main = /* Objects loaded at program startup */ 232 STAILQ_HEAD_INITIALIZER(list_main); 233 static Objlist list_fini = /* Objects needing fini() calls */ 234 STAILQ_HEAD_INITIALIZER(list_fini); 235 236 Elf_Sym sym_zero; /* For resolving undefined weak refs. */ 237 238 #define GDB_STATE(s,m) r_debug.r_state = s; r_debug_state(&r_debug,m); 239 240 extern Elf_Dyn _DYNAMIC; 241 #pragma weak _DYNAMIC 242 243 int dlclose(void *) __exported; 244 char *dlerror(void) __exported; 245 void *dlopen(const char *, int) __exported; 246 void *fdlopen(int, int) __exported; 247 void *dlsym(void *, const char *) __exported; 248 dlfunc_t dlfunc(void *, const char *) __exported; 249 void *dlvsym(void *, const char *, const char *) __exported; 250 int dladdr(const void *, Dl_info *) __exported; 251 void dllockinit(void *, void *(*)(void *), void (*)(void *), void (*)(void *), 252 void (*)(void *), void (*)(void *), void (*)(void *)) __exported; 253 int dlinfo(void *, int , void *) __exported; 254 int dl_iterate_phdr(__dl_iterate_hdr_callback, void *) __exported; 255 int _rtld_addr_phdr(const void *, struct dl_phdr_info *) __exported; 256 int _rtld_get_stack_prot(void) __exported; 257 int _rtld_is_dlopened(void *) __exported; 258 void _rtld_error(const char *, ...) __exported; 259 260 /* Only here to fix -Wmissing-prototypes warnings */ 261 int __getosreldate(void); 262 func_ptr_type _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp); 263 Elf_Addr _rtld_bind(Obj_Entry *obj, Elf_Size reloff); 264 265 266 int npagesizes; 267 static int osreldate; 268 size_t *pagesizes; 269 270 static int stack_prot = PROT_READ | PROT_WRITE | RTLD_DEFAULT_STACK_EXEC; 271 static int max_stack_flags; 272 273 /* 274 * Global declarations normally provided by crt1. The dynamic linker is 275 * not built with crt1, so we have to provide them ourselves. 276 */ 277 char *__progname; 278 char **environ; 279 280 /* 281 * Used to pass argc, argv to init functions. 282 */ 283 int main_argc; 284 char **main_argv; 285 286 /* 287 * Globals to control TLS allocation. 288 */ 289 size_t tls_last_offset; /* Static TLS offset of last module */ 290 size_t tls_last_size; /* Static TLS size of last module */ 291 size_t tls_static_space; /* Static TLS space allocated */ 292 static size_t tls_static_max_align; 293 Elf_Addr tls_dtv_generation = 1; /* Used to detect when dtv size changes */ 294 int tls_max_index = 1; /* Largest module index allocated */ 295 296 static bool ld_library_path_rpath = false; 297 bool ld_fast_sigblock = false; 298 299 /* 300 * Globals for path names, and such 301 */ 302 const char *ld_elf_hints_default = _PATH_ELF_HINTS; 303 const char *ld_path_libmap_conf = _PATH_LIBMAP_CONF; 304 const char *ld_path_rtld = _PATH_RTLD; 305 const char *ld_standard_library_path = STANDARD_LIBRARY_PATH; 306 const char *ld_env_prefix = LD_; 307 308 static void (*rtld_exit_ptr)(void); 309 310 /* 311 * Fill in a DoneList with an allocation large enough to hold all of 312 * the currently-loaded objects. Keep this as a macro since it calls 313 * alloca and we want that to occur within the scope of the caller. 314 */ 315 #define donelist_init(dlp) \ 316 ((dlp)->objs = alloca(obj_count * sizeof (dlp)->objs[0]), \ 317 assert((dlp)->objs != NULL), \ 318 (dlp)->num_alloc = obj_count, \ 319 (dlp)->num_used = 0) 320 321 #define LD_UTRACE(e, h, mb, ms, r, n) do { \ 322 if (ld_utrace != NULL) \ 323 ld_utrace_log(e, h, mb, ms, r, n); \ 324 } while (0) 325 326 static void 327 ld_utrace_log(int event, void *handle, void *mapbase, size_t mapsize, 328 int refcnt, const char *name) 329 { 330 struct utrace_rtld ut; 331 static const char rtld_utrace_sig[RTLD_UTRACE_SIG_SZ] = RTLD_UTRACE_SIG; 332 333 memcpy(ut.sig, rtld_utrace_sig, sizeof(ut.sig)); 334 ut.event = event; 335 ut.handle = handle; 336 ut.mapbase = mapbase; 337 ut.mapsize = mapsize; 338 ut.refcnt = refcnt; 339 bzero(ut.name, sizeof(ut.name)); 340 if (name) 341 strlcpy(ut.name, name, sizeof(ut.name)); 342 utrace(&ut, sizeof(ut)); 343 } 344 345 #ifdef RTLD_VARIANT_ENV_NAMES 346 /* 347 * construct the env variable based on the type of binary that's 348 * running. 349 */ 350 static inline const char * 351 _LD(const char *var) 352 { 353 static char buffer[128]; 354 355 strlcpy(buffer, ld_env_prefix, sizeof(buffer)); 356 strlcat(buffer, var, sizeof(buffer)); 357 return (buffer); 358 } 359 #else 360 #define _LD(x) LD_ x 361 #endif 362 363 /* 364 * Main entry point for dynamic linking. The first argument is the 365 * stack pointer. The stack is expected to be laid out as described 366 * in the SVR4 ABI specification, Intel 386 Processor Supplement. 367 * Specifically, the stack pointer points to a word containing 368 * ARGC. Following that in the stack is a null-terminated sequence 369 * of pointers to argument strings. Then comes a null-terminated 370 * sequence of pointers to environment strings. Finally, there is a 371 * sequence of "auxiliary vector" entries. 372 * 373 * The second argument points to a place to store the dynamic linker's 374 * exit procedure pointer and the third to a place to store the main 375 * program's object. 376 * 377 * The return value is the main program's entry point. 378 */ 379 func_ptr_type 380 _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp) 381 { 382 Elf_Auxinfo *aux, *auxp, *auxpf, *aux_info[AT_COUNT]; 383 Objlist_Entry *entry; 384 Obj_Entry *last_interposer, *obj, *preload_tail; 385 const Elf_Phdr *phdr; 386 Objlist initlist; 387 RtldLockState lockstate; 388 struct stat st; 389 Elf_Addr *argcp; 390 char **argv, **env, **envp, *kexecpath, *library_path_rpath; 391 const char *argv0, *binpath; 392 caddr_t imgentry; 393 char buf[MAXPATHLEN]; 394 int argc, fd, i, mib[4], old_osrel, osrel, phnum, rtld_argc; 395 size_t sz; 396 #ifdef __powerpc__ 397 int old_auxv_format = 1; 398 #endif 399 bool dir_enable, direct_exec, explicit_fd, search_in_path; 400 401 /* 402 * On entry, the dynamic linker itself has not been relocated yet. 403 * Be very careful not to reference any global data until after 404 * init_rtld has returned. It is OK to reference file-scope statics 405 * and string constants, and to call static and global functions. 406 */ 407 408 /* Find the auxiliary vector on the stack. */ 409 argcp = sp; 410 argc = *sp++; 411 argv = (char **) sp; 412 sp += argc + 1; /* Skip over arguments and NULL terminator */ 413 env = (char **) sp; 414 while (*sp++ != 0) /* Skip over environment, and NULL terminator */ 415 ; 416 aux = (Elf_Auxinfo *) sp; 417 418 /* Digest the auxiliary vector. */ 419 for (i = 0; i < AT_COUNT; i++) 420 aux_info[i] = NULL; 421 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) { 422 if (auxp->a_type < AT_COUNT) 423 aux_info[auxp->a_type] = auxp; 424 #ifdef __powerpc__ 425 if (auxp->a_type == 23) /* AT_STACKPROT */ 426 old_auxv_format = 0; 427 #endif 428 } 429 430 #ifdef __powerpc__ 431 if (old_auxv_format) { 432 /* Remap from old-style auxv numbers. */ 433 aux_info[23] = aux_info[21]; /* AT_STACKPROT */ 434 aux_info[21] = aux_info[19]; /* AT_PAGESIZESLEN */ 435 aux_info[19] = aux_info[17]; /* AT_NCPUS */ 436 aux_info[17] = aux_info[15]; /* AT_CANARYLEN */ 437 aux_info[15] = aux_info[13]; /* AT_EXECPATH */ 438 aux_info[13] = NULL; /* AT_GID */ 439 440 aux_info[20] = aux_info[18]; /* AT_PAGESIZES */ 441 aux_info[18] = aux_info[16]; /* AT_OSRELDATE */ 442 aux_info[16] = aux_info[14]; /* AT_CANARY */ 443 aux_info[14] = NULL; /* AT_EGID */ 444 } 445 #endif 446 447 /* Initialize and relocate ourselves. */ 448 assert(aux_info[AT_BASE] != NULL); 449 init_rtld((caddr_t) aux_info[AT_BASE]->a_un.a_ptr, aux_info); 450 451 dlerror_dflt_init(); 452 453 __progname = obj_rtld.path; 454 argv0 = argv[0] != NULL ? argv[0] : "(null)"; 455 environ = env; 456 main_argc = argc; 457 main_argv = argv; 458 459 if (aux_info[AT_BSDFLAGS] != NULL && 460 (aux_info[AT_BSDFLAGS]->a_un.a_val & ELF_BSDF_SIGFASTBLK) != 0) 461 ld_fast_sigblock = true; 462 463 trust = !issetugid(); 464 direct_exec = false; 465 466 md_abi_variant_hook(aux_info); 467 468 fd = -1; 469 if (aux_info[AT_EXECFD] != NULL) { 470 fd = aux_info[AT_EXECFD]->a_un.a_val; 471 } else { 472 assert(aux_info[AT_PHDR] != NULL); 473 phdr = (const Elf_Phdr *)aux_info[AT_PHDR]->a_un.a_ptr; 474 if (phdr == obj_rtld.phdr) { 475 if (!trust) { 476 _rtld_error("Tainted process refusing to run binary %s", 477 argv0); 478 rtld_die(); 479 } 480 direct_exec = true; 481 482 dbg("opening main program in direct exec mode"); 483 if (argc >= 2) { 484 rtld_argc = parse_args(argv, argc, &search_in_path, &fd, &argv0); 485 explicit_fd = (fd != -1); 486 binpath = NULL; 487 if (!explicit_fd) 488 fd = open_binary_fd(argv0, search_in_path, &binpath); 489 if (fstat(fd, &st) == -1) { 490 _rtld_error("Failed to fstat FD %d (%s): %s", fd, 491 explicit_fd ? "user-provided descriptor" : argv0, 492 rtld_strerror(errno)); 493 rtld_die(); 494 } 495 496 /* 497 * Rough emulation of the permission checks done by 498 * execve(2), only Unix DACs are checked, ACLs are 499 * ignored. Preserve the semantic of disabling owner 500 * to execute if owner x bit is cleared, even if 501 * others x bit is enabled. 502 * mmap(2) does not allow to mmap with PROT_EXEC if 503 * binary' file comes from noexec mount. We cannot 504 * set a text reference on the binary. 505 */ 506 dir_enable = false; 507 if (st.st_uid == geteuid()) { 508 if ((st.st_mode & S_IXUSR) != 0) 509 dir_enable = true; 510 } else if (st.st_gid == getegid()) { 511 if ((st.st_mode & S_IXGRP) != 0) 512 dir_enable = true; 513 } else if ((st.st_mode & S_IXOTH) != 0) { 514 dir_enable = true; 515 } 516 if (!dir_enable) { 517 _rtld_error("No execute permission for binary %s", 518 argv0); 519 rtld_die(); 520 } 521 522 /* 523 * For direct exec mode, argv[0] is the interpreter 524 * name, we must remove it and shift arguments left 525 * before invoking binary main. Since stack layout 526 * places environment pointers and aux vectors right 527 * after the terminating NULL, we must shift 528 * environment and aux as well. 529 */ 530 main_argc = argc - rtld_argc; 531 for (i = 0; i <= main_argc; i++) 532 argv[i] = argv[i + rtld_argc]; 533 *argcp -= rtld_argc; 534 environ = env = envp = argv + main_argc + 1; 535 dbg("move env from %p to %p", envp + rtld_argc, envp); 536 do { 537 *envp = *(envp + rtld_argc); 538 } while (*envp++ != NULL); 539 aux = auxp = (Elf_Auxinfo *)envp; 540 auxpf = (Elf_Auxinfo *)(envp + rtld_argc); 541 dbg("move aux from %p to %p", auxpf, aux); 542 /* XXXKIB insert place for AT_EXECPATH if not present */ 543 for (;; auxp++, auxpf++) { 544 *auxp = *auxpf; 545 if (auxp->a_type == AT_NULL) 546 break; 547 } 548 /* Since the auxiliary vector has moved, redigest it. */ 549 for (i = 0; i < AT_COUNT; i++) 550 aux_info[i] = NULL; 551 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) { 552 if (auxp->a_type < AT_COUNT) 553 aux_info[auxp->a_type] = auxp; 554 } 555 556 /* Point AT_EXECPATH auxv and aux_info to the binary path. */ 557 if (binpath == NULL) { 558 aux_info[AT_EXECPATH] = NULL; 559 } else { 560 if (aux_info[AT_EXECPATH] == NULL) { 561 aux_info[AT_EXECPATH] = xmalloc(sizeof(Elf_Auxinfo)); 562 aux_info[AT_EXECPATH]->a_type = AT_EXECPATH; 563 } 564 aux_info[AT_EXECPATH]->a_un.a_ptr = __DECONST(void *, 565 binpath); 566 } 567 } else { 568 _rtld_error("No binary"); 569 rtld_die(); 570 } 571 } 572 } 573 574 ld_bind_now = getenv(_LD("BIND_NOW")); 575 576 /* 577 * If the process is tainted, then we un-set the dangerous environment 578 * variables. The process will be marked as tainted until setuid(2) 579 * is called. If any child process calls setuid(2) we do not want any 580 * future processes to honor the potentially un-safe variables. 581 */ 582 if (!trust) { 583 if (unsetenv(_LD("PRELOAD")) || unsetenv(_LD("LIBMAP")) || 584 unsetenv(_LD("LIBRARY_PATH")) || unsetenv(_LD("LIBRARY_PATH_FDS")) || 585 unsetenv(_LD("LIBMAP_DISABLE")) || unsetenv(_LD("BIND_NOT")) || 586 unsetenv(_LD("DEBUG")) || unsetenv(_LD("ELF_HINTS_PATH")) || 587 unsetenv(_LD("LOADFLTR")) || unsetenv(_LD("LIBRARY_PATH_RPATH")) || 588 unsetenv(_LD("PRELOAD_FDS")) || unsetenv(_LD("DYNAMIC_WEAK"))) { 589 _rtld_error("environment corrupt; aborting"); 590 rtld_die(); 591 } 592 } 593 ld_debug = getenv(_LD("DEBUG")); 594 if (ld_bind_now == NULL) 595 ld_bind_not = getenv(_LD("BIND_NOT")) != NULL; 596 ld_dynamic_weak = getenv(_LD("DYNAMIC_WEAK")) == NULL; 597 libmap_disable = getenv(_LD("LIBMAP_DISABLE")) != NULL; 598 libmap_override = getenv(_LD("LIBMAP")); 599 ld_library_path = getenv(_LD("LIBRARY_PATH")); 600 ld_library_dirs = getenv(_LD("LIBRARY_PATH_FDS")); 601 ld_preload = getenv(_LD("PRELOAD")); 602 ld_preload_fds = getenv(_LD("PRELOAD_FDS")); 603 ld_elf_hints_path = getenv(_LD("ELF_HINTS_PATH")); 604 ld_loadfltr = getenv(_LD("LOADFLTR")) != NULL; 605 library_path_rpath = getenv(_LD("LIBRARY_PATH_RPATH")); 606 if (library_path_rpath != NULL) { 607 if (library_path_rpath[0] == 'y' || 608 library_path_rpath[0] == 'Y' || 609 library_path_rpath[0] == '1') 610 ld_library_path_rpath = true; 611 else 612 ld_library_path_rpath = false; 613 } 614 dangerous_ld_env = libmap_disable || (libmap_override != NULL) || 615 (ld_library_path != NULL) || (ld_preload != NULL) || 616 (ld_elf_hints_path != NULL) || ld_loadfltr || ld_dynamic_weak; 617 ld_tracing = getenv(_LD("TRACE_LOADED_OBJECTS")); 618 ld_utrace = getenv(_LD("UTRACE")); 619 620 if ((ld_elf_hints_path == NULL) || strlen(ld_elf_hints_path) == 0) 621 ld_elf_hints_path = ld_elf_hints_default; 622 623 if (ld_debug != NULL && *ld_debug != '\0') 624 debug = 1; 625 dbg("%s is initialized, base address = %p", __progname, 626 (caddr_t) aux_info[AT_BASE]->a_un.a_ptr); 627 dbg("RTLD dynamic = %p", obj_rtld.dynamic); 628 dbg("RTLD pltgot = %p", obj_rtld.pltgot); 629 630 dbg("initializing thread locks"); 631 lockdflt_init(); 632 633 /* 634 * Load the main program, or process its program header if it is 635 * already loaded. 636 */ 637 if (fd != -1) { /* Load the main program. */ 638 dbg("loading main program"); 639 obj_main = map_object(fd, argv0, NULL); 640 close(fd); 641 if (obj_main == NULL) 642 rtld_die(); 643 max_stack_flags = obj_main->stack_flags; 644 } else { /* Main program already loaded. */ 645 dbg("processing main program's program header"); 646 assert(aux_info[AT_PHDR] != NULL); 647 phdr = (const Elf_Phdr *) aux_info[AT_PHDR]->a_un.a_ptr; 648 assert(aux_info[AT_PHNUM] != NULL); 649 phnum = aux_info[AT_PHNUM]->a_un.a_val; 650 assert(aux_info[AT_PHENT] != NULL); 651 assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr)); 652 assert(aux_info[AT_ENTRY] != NULL); 653 imgentry = (caddr_t) aux_info[AT_ENTRY]->a_un.a_ptr; 654 if ((obj_main = digest_phdr(phdr, phnum, imgentry, argv0)) == NULL) 655 rtld_die(); 656 } 657 658 if (aux_info[AT_EXECPATH] != NULL && fd == -1) { 659 kexecpath = aux_info[AT_EXECPATH]->a_un.a_ptr; 660 dbg("AT_EXECPATH %p %s", kexecpath, kexecpath); 661 if (kexecpath[0] == '/') 662 obj_main->path = kexecpath; 663 else if (getcwd(buf, sizeof(buf)) == NULL || 664 strlcat(buf, "/", sizeof(buf)) >= sizeof(buf) || 665 strlcat(buf, kexecpath, sizeof(buf)) >= sizeof(buf)) 666 obj_main->path = xstrdup(argv0); 667 else 668 obj_main->path = xstrdup(buf); 669 } else { 670 dbg("No AT_EXECPATH or direct exec"); 671 obj_main->path = xstrdup(argv0); 672 } 673 dbg("obj_main path %s", obj_main->path); 674 obj_main->mainprog = true; 675 676 if (aux_info[AT_STACKPROT] != NULL && 677 aux_info[AT_STACKPROT]->a_un.a_val != 0) 678 stack_prot = aux_info[AT_STACKPROT]->a_un.a_val; 679 680 #ifndef COMPAT_32BIT 681 /* 682 * Get the actual dynamic linker pathname from the executable if 683 * possible. (It should always be possible.) That ensures that 684 * gdb will find the right dynamic linker even if a non-standard 685 * one is being used. 686 */ 687 if (obj_main->interp != NULL && 688 strcmp(obj_main->interp, obj_rtld.path) != 0) { 689 free(obj_rtld.path); 690 obj_rtld.path = xstrdup(obj_main->interp); 691 __progname = obj_rtld.path; 692 } 693 #endif 694 695 if (!digest_dynamic(obj_main, 0)) 696 rtld_die(); 697 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", 698 obj_main->path, obj_main->valid_hash_sysv, obj_main->valid_hash_gnu, 699 obj_main->dynsymcount); 700 701 linkmap_add(obj_main); 702 linkmap_add(&obj_rtld); 703 704 /* Link the main program into the list of objects. */ 705 TAILQ_INSERT_HEAD(&obj_list, obj_main, next); 706 obj_count++; 707 obj_loads++; 708 709 /* Initialize a fake symbol for resolving undefined weak references. */ 710 sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE); 711 sym_zero.st_shndx = SHN_UNDEF; 712 sym_zero.st_value = -(uintptr_t)obj_main->relocbase; 713 714 if (!libmap_disable) 715 libmap_disable = (bool)lm_init(libmap_override); 716 717 dbg("loading LD_PRELOAD_FDS libraries"); 718 if (load_preload_objects(ld_preload_fds, true) == -1) 719 rtld_die(); 720 721 dbg("loading LD_PRELOAD libraries"); 722 if (load_preload_objects(ld_preload, false) == -1) 723 rtld_die(); 724 preload_tail = globallist_curr(TAILQ_LAST(&obj_list, obj_entry_q)); 725 726 dbg("loading needed objects"); 727 if (load_needed_objects(obj_main, ld_tracing != NULL ? RTLD_LO_TRACE : 728 0) == -1) 729 rtld_die(); 730 731 /* Make a list of all objects loaded at startup. */ 732 last_interposer = obj_main; 733 TAILQ_FOREACH(obj, &obj_list, next) { 734 if (obj->marker) 735 continue; 736 if (obj->z_interpose && obj != obj_main) { 737 objlist_put_after(&list_main, last_interposer, obj); 738 last_interposer = obj; 739 } else { 740 objlist_push_tail(&list_main, obj); 741 } 742 obj->refcount++; 743 } 744 745 dbg("checking for required versions"); 746 if (rtld_verify_versions(&list_main) == -1 && !ld_tracing) 747 rtld_die(); 748 749 if (ld_tracing) { /* We're done */ 750 trace_loaded_objects(obj_main); 751 exit(0); 752 } 753 754 if (getenv(_LD("DUMP_REL_PRE")) != NULL) { 755 dump_relocations(obj_main); 756 exit (0); 757 } 758 759 /* 760 * Processing tls relocations requires having the tls offsets 761 * initialized. Prepare offsets before starting initial 762 * relocation processing. 763 */ 764 dbg("initializing initial thread local storage offsets"); 765 STAILQ_FOREACH(entry, &list_main, link) { 766 /* 767 * Allocate all the initial objects out of the static TLS 768 * block even if they didn't ask for it. 769 */ 770 allocate_tls_offset(entry->obj); 771 } 772 773 if (relocate_objects(obj_main, 774 ld_bind_now != NULL && *ld_bind_now != '\0', 775 &obj_rtld, SYMLOOK_EARLY, NULL) == -1) 776 rtld_die(); 777 778 dbg("doing copy relocations"); 779 if (do_copy_relocations(obj_main) == -1) 780 rtld_die(); 781 782 if (getenv(_LD("DUMP_REL_POST")) != NULL) { 783 dump_relocations(obj_main); 784 exit (0); 785 } 786 787 ifunc_init(aux); 788 789 /* 790 * Setup TLS for main thread. This must be done after the 791 * relocations are processed, since tls initialization section 792 * might be the subject for relocations. 793 */ 794 dbg("initializing initial thread local storage"); 795 allocate_initial_tls(globallist_curr(TAILQ_FIRST(&obj_list))); 796 797 dbg("initializing key program variables"); 798 set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : ""); 799 set_program_var("environ", env); 800 set_program_var("__elf_aux_vector", aux); 801 802 /* Make a list of init functions to call. */ 803 objlist_init(&initlist); 804 initlist_add_objects(globallist_curr(TAILQ_FIRST(&obj_list)), 805 preload_tail, &initlist); 806 807 r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */ 808 809 map_stacks_exec(NULL); 810 811 if (!obj_main->crt_no_init) { 812 /* 813 * Make sure we don't call the main program's init and fini 814 * functions for binaries linked with old crt1 which calls 815 * _init itself. 816 */ 817 obj_main->init = obj_main->fini = (Elf_Addr)NULL; 818 obj_main->preinit_array = obj_main->init_array = 819 obj_main->fini_array = (Elf_Addr)NULL; 820 } 821 822 if (direct_exec) { 823 /* Set osrel for direct-execed binary */ 824 mib[0] = CTL_KERN; 825 mib[1] = KERN_PROC; 826 mib[2] = KERN_PROC_OSREL; 827 mib[3] = getpid(); 828 osrel = obj_main->osrel; 829 sz = sizeof(old_osrel); 830 dbg("setting osrel to %d", osrel); 831 (void)sysctl(mib, 4, &old_osrel, &sz, &osrel, sizeof(osrel)); 832 } 833 834 wlock_acquire(rtld_bind_lock, &lockstate); 835 836 dbg("resolving ifuncs"); 837 if (initlist_objects_ifunc(&initlist, ld_bind_now != NULL && 838 *ld_bind_now != '\0', SYMLOOK_EARLY, &lockstate) == -1) 839 rtld_die(); 840 841 rtld_exit_ptr = rtld_exit; 842 if (obj_main->crt_no_init) 843 preinit_main(); 844 objlist_call_init(&initlist, &lockstate); 845 _r_debug_postinit(&obj_main->linkmap); 846 objlist_clear(&initlist); 847 dbg("loading filtees"); 848 TAILQ_FOREACH(obj, &obj_list, next) { 849 if (obj->marker) 850 continue; 851 if (ld_loadfltr || obj->z_loadfltr) 852 load_filtees(obj, 0, &lockstate); 853 } 854 855 dbg("enforcing main obj relro"); 856 if (obj_enforce_relro(obj_main) == -1) 857 rtld_die(); 858 859 lock_release(rtld_bind_lock, &lockstate); 860 861 dbg("transferring control to program entry point = %p", obj_main->entry); 862 863 /* Return the exit procedure and the program entry point. */ 864 *exit_proc = rtld_exit_ptr; 865 *objp = obj_main; 866 return (func_ptr_type) obj_main->entry; 867 } 868 869 void * 870 rtld_resolve_ifunc(const Obj_Entry *obj, const Elf_Sym *def) 871 { 872 void *ptr; 873 Elf_Addr target; 874 875 ptr = (void *)make_function_pointer(def, obj); 876 target = call_ifunc_resolver(ptr); 877 return ((void *)target); 878 } 879 880 /* 881 * NB: MIPS uses a private version of this function (_mips_rtld_bind). 882 * Changes to this function should be applied there as well. 883 */ 884 Elf_Addr 885 _rtld_bind(Obj_Entry *obj, Elf_Size reloff) 886 { 887 const Elf_Rel *rel; 888 const Elf_Sym *def; 889 const Obj_Entry *defobj; 890 Elf_Addr *where; 891 Elf_Addr target; 892 RtldLockState lockstate; 893 894 rlock_acquire(rtld_bind_lock, &lockstate); 895 if (sigsetjmp(lockstate.env, 0) != 0) 896 lock_upgrade(rtld_bind_lock, &lockstate); 897 if (obj->pltrel) 898 rel = (const Elf_Rel *)((const char *)obj->pltrel + reloff); 899 else 900 rel = (const Elf_Rel *)((const char *)obj->pltrela + reloff); 901 902 where = (Elf_Addr *)(obj->relocbase + rel->r_offset); 903 def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, SYMLOOK_IN_PLT, 904 NULL, &lockstate); 905 if (def == NULL) 906 rtld_die(); 907 if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 908 target = (Elf_Addr)rtld_resolve_ifunc(defobj, def); 909 else 910 target = (Elf_Addr)(defobj->relocbase + def->st_value); 911 912 dbg("\"%s\" in \"%s\" ==> %p in \"%s\"", 913 defobj->strtab + def->st_name, 914 obj->path == NULL ? NULL : basename(obj->path), 915 (void *)target, 916 defobj->path == NULL ? NULL : basename(defobj->path)); 917 918 /* 919 * Write the new contents for the jmpslot. Note that depending on 920 * architecture, the value which we need to return back to the 921 * lazy binding trampoline may or may not be the target 922 * address. The value returned from reloc_jmpslot() is the value 923 * that the trampoline needs. 924 */ 925 target = reloc_jmpslot(where, target, defobj, obj, rel); 926 lock_release(rtld_bind_lock, &lockstate); 927 return target; 928 } 929 930 /* 931 * Error reporting function. Use it like printf. If formats the message 932 * into a buffer, and sets things up so that the next call to dlerror() 933 * will return the message. 934 */ 935 void 936 _rtld_error(const char *fmt, ...) 937 { 938 va_list ap; 939 940 va_start(ap, fmt); 941 rtld_vsnprintf(lockinfo.dlerror_loc(), lockinfo.dlerror_loc_sz, 942 fmt, ap); 943 va_end(ap); 944 *lockinfo.dlerror_seen() = 0; 945 LD_UTRACE(UTRACE_RTLD_ERROR, NULL, NULL, 0, 0, lockinfo.dlerror_loc()); 946 } 947 948 /* 949 * Return a dynamically-allocated copy of the current error message, if any. 950 */ 951 static struct dlerror_save * 952 errmsg_save(void) 953 { 954 struct dlerror_save *res; 955 956 res = xmalloc(sizeof(*res)); 957 res->seen = *lockinfo.dlerror_seen(); 958 if (res->seen == 0) 959 res->msg = xstrdup(lockinfo.dlerror_loc()); 960 return (res); 961 } 962 963 /* 964 * Restore the current error message from a copy which was previously saved 965 * by errmsg_save(). The copy is freed. 966 */ 967 static void 968 errmsg_restore(struct dlerror_save *saved_msg) 969 { 970 if (saved_msg == NULL || saved_msg->seen == 1) { 971 *lockinfo.dlerror_seen() = 1; 972 } else { 973 *lockinfo.dlerror_seen() = 0; 974 strlcpy(lockinfo.dlerror_loc(), saved_msg->msg, 975 lockinfo.dlerror_loc_sz); 976 free(saved_msg->msg); 977 } 978 free(saved_msg); 979 } 980 981 static const char * 982 basename(const char *name) 983 { 984 const char *p = strrchr(name, '/'); 985 return p != NULL ? p + 1 : name; 986 } 987 988 static struct utsname uts; 989 990 static char * 991 origin_subst_one(Obj_Entry *obj, char *real, const char *kw, 992 const char *subst, bool may_free) 993 { 994 char *p, *p1, *res, *resp; 995 int subst_len, kw_len, subst_count, old_len, new_len; 996 997 kw_len = strlen(kw); 998 999 /* 1000 * First, count the number of the keyword occurrences, to 1001 * preallocate the final string. 1002 */ 1003 for (p = real, subst_count = 0;; p = p1 + kw_len, subst_count++) { 1004 p1 = strstr(p, kw); 1005 if (p1 == NULL) 1006 break; 1007 } 1008 1009 /* 1010 * If the keyword is not found, just return. 1011 * 1012 * Return non-substituted string if resolution failed. We 1013 * cannot do anything more reasonable, the failure mode of the 1014 * caller is unresolved library anyway. 1015 */ 1016 if (subst_count == 0 || (obj != NULL && !obj_resolve_origin(obj))) 1017 return (may_free ? real : xstrdup(real)); 1018 if (obj != NULL) 1019 subst = obj->origin_path; 1020 1021 /* 1022 * There is indeed something to substitute. Calculate the 1023 * length of the resulting string, and allocate it. 1024 */ 1025 subst_len = strlen(subst); 1026 old_len = strlen(real); 1027 new_len = old_len + (subst_len - kw_len) * subst_count; 1028 res = xmalloc(new_len + 1); 1029 1030 /* 1031 * Now, execute the substitution loop. 1032 */ 1033 for (p = real, resp = res, *resp = '\0';;) { 1034 p1 = strstr(p, kw); 1035 if (p1 != NULL) { 1036 /* Copy the prefix before keyword. */ 1037 memcpy(resp, p, p1 - p); 1038 resp += p1 - p; 1039 /* Keyword replacement. */ 1040 memcpy(resp, subst, subst_len); 1041 resp += subst_len; 1042 *resp = '\0'; 1043 p = p1 + kw_len; 1044 } else 1045 break; 1046 } 1047 1048 /* Copy to the end of string and finish. */ 1049 strcat(resp, p); 1050 if (may_free) 1051 free(real); 1052 return (res); 1053 } 1054 1055 static char * 1056 origin_subst(Obj_Entry *obj, const char *real) 1057 { 1058 char *res1, *res2, *res3, *res4; 1059 1060 if (obj == NULL || !trust) 1061 return (xstrdup(real)); 1062 if (uts.sysname[0] == '\0') { 1063 if (uname(&uts) != 0) { 1064 _rtld_error("utsname failed: %d", errno); 1065 return (NULL); 1066 } 1067 } 1068 /* __DECONST is safe here since without may_free real is unchanged */ 1069 res1 = origin_subst_one(obj, __DECONST(char *, real), "$ORIGIN", NULL, 1070 false); 1071 res2 = origin_subst_one(NULL, res1, "$OSNAME", uts.sysname, true); 1072 res3 = origin_subst_one(NULL, res2, "$OSREL", uts.release, true); 1073 res4 = origin_subst_one(NULL, res3, "$PLATFORM", uts.machine, true); 1074 return (res4); 1075 } 1076 1077 void 1078 rtld_die(void) 1079 { 1080 const char *msg = dlerror(); 1081 1082 if (msg == NULL) 1083 msg = "Fatal error"; 1084 rtld_fdputstr(STDERR_FILENO, _BASENAME_RTLD ": "); 1085 rtld_fdputstr(STDERR_FILENO, msg); 1086 rtld_fdputchar(STDERR_FILENO, '\n'); 1087 _exit(1); 1088 } 1089 1090 /* 1091 * Process a shared object's DYNAMIC section, and save the important 1092 * information in its Obj_Entry structure. 1093 */ 1094 static void 1095 digest_dynamic1(Obj_Entry *obj, int early, const Elf_Dyn **dyn_rpath, 1096 const Elf_Dyn **dyn_soname, const Elf_Dyn **dyn_runpath) 1097 { 1098 const Elf_Dyn *dynp; 1099 Needed_Entry **needed_tail = &obj->needed; 1100 Needed_Entry **needed_filtees_tail = &obj->needed_filtees; 1101 Needed_Entry **needed_aux_filtees_tail = &obj->needed_aux_filtees; 1102 const Elf_Hashelt *hashtab; 1103 const Elf32_Word *hashval; 1104 Elf32_Word bkt, nmaskwords; 1105 int bloom_size32; 1106 int plttype = DT_REL; 1107 1108 *dyn_rpath = NULL; 1109 *dyn_soname = NULL; 1110 *dyn_runpath = NULL; 1111 1112 obj->bind_now = false; 1113 dynp = obj->dynamic; 1114 if (dynp == NULL) 1115 return; 1116 for (; dynp->d_tag != DT_NULL; dynp++) { 1117 switch (dynp->d_tag) { 1118 1119 case DT_REL: 1120 obj->rel = (const Elf_Rel *)(obj->relocbase + dynp->d_un.d_ptr); 1121 break; 1122 1123 case DT_RELSZ: 1124 obj->relsize = dynp->d_un.d_val; 1125 break; 1126 1127 case DT_RELENT: 1128 assert(dynp->d_un.d_val == sizeof(Elf_Rel)); 1129 break; 1130 1131 case DT_JMPREL: 1132 obj->pltrel = (const Elf_Rel *) 1133 (obj->relocbase + dynp->d_un.d_ptr); 1134 break; 1135 1136 case DT_PLTRELSZ: 1137 obj->pltrelsize = dynp->d_un.d_val; 1138 break; 1139 1140 case DT_RELA: 1141 obj->rela = (const Elf_Rela *)(obj->relocbase + dynp->d_un.d_ptr); 1142 break; 1143 1144 case DT_RELASZ: 1145 obj->relasize = dynp->d_un.d_val; 1146 break; 1147 1148 case DT_RELAENT: 1149 assert(dynp->d_un.d_val == sizeof(Elf_Rela)); 1150 break; 1151 1152 case DT_PLTREL: 1153 plttype = dynp->d_un.d_val; 1154 assert(dynp->d_un.d_val == DT_REL || plttype == DT_RELA); 1155 break; 1156 1157 case DT_SYMTAB: 1158 obj->symtab = (const Elf_Sym *) 1159 (obj->relocbase + dynp->d_un.d_ptr); 1160 break; 1161 1162 case DT_SYMENT: 1163 assert(dynp->d_un.d_val == sizeof(Elf_Sym)); 1164 break; 1165 1166 case DT_STRTAB: 1167 obj->strtab = (const char *)(obj->relocbase + dynp->d_un.d_ptr); 1168 break; 1169 1170 case DT_STRSZ: 1171 obj->strsize = dynp->d_un.d_val; 1172 break; 1173 1174 case DT_VERNEED: 1175 obj->verneed = (const Elf_Verneed *)(obj->relocbase + 1176 dynp->d_un.d_val); 1177 break; 1178 1179 case DT_VERNEEDNUM: 1180 obj->verneednum = dynp->d_un.d_val; 1181 break; 1182 1183 case DT_VERDEF: 1184 obj->verdef = (const Elf_Verdef *)(obj->relocbase + 1185 dynp->d_un.d_val); 1186 break; 1187 1188 case DT_VERDEFNUM: 1189 obj->verdefnum = dynp->d_un.d_val; 1190 break; 1191 1192 case DT_VERSYM: 1193 obj->versyms = (const Elf_Versym *)(obj->relocbase + 1194 dynp->d_un.d_val); 1195 break; 1196 1197 case DT_HASH: 1198 { 1199 hashtab = (const Elf_Hashelt *)(obj->relocbase + 1200 dynp->d_un.d_ptr); 1201 obj->nbuckets = hashtab[0]; 1202 obj->nchains = hashtab[1]; 1203 obj->buckets = hashtab + 2; 1204 obj->chains = obj->buckets + obj->nbuckets; 1205 obj->valid_hash_sysv = obj->nbuckets > 0 && obj->nchains > 0 && 1206 obj->buckets != NULL; 1207 } 1208 break; 1209 1210 case DT_GNU_HASH: 1211 { 1212 hashtab = (const Elf_Hashelt *)(obj->relocbase + 1213 dynp->d_un.d_ptr); 1214 obj->nbuckets_gnu = hashtab[0]; 1215 obj->symndx_gnu = hashtab[1]; 1216 nmaskwords = hashtab[2]; 1217 bloom_size32 = (__ELF_WORD_SIZE / 32) * nmaskwords; 1218 obj->maskwords_bm_gnu = nmaskwords - 1; 1219 obj->shift2_gnu = hashtab[3]; 1220 obj->bloom_gnu = (const Elf_Addr *)(hashtab + 4); 1221 obj->buckets_gnu = hashtab + 4 + bloom_size32; 1222 obj->chain_zero_gnu = obj->buckets_gnu + obj->nbuckets_gnu - 1223 obj->symndx_gnu; 1224 /* Number of bitmask words is required to be power of 2 */ 1225 obj->valid_hash_gnu = powerof2(nmaskwords) && 1226 obj->nbuckets_gnu > 0 && obj->buckets_gnu != NULL; 1227 } 1228 break; 1229 1230 case DT_NEEDED: 1231 if (!obj->rtld) { 1232 Needed_Entry *nep = NEW(Needed_Entry); 1233 nep->name = dynp->d_un.d_val; 1234 nep->obj = NULL; 1235 nep->next = NULL; 1236 1237 *needed_tail = nep; 1238 needed_tail = &nep->next; 1239 } 1240 break; 1241 1242 case DT_FILTER: 1243 if (!obj->rtld) { 1244 Needed_Entry *nep = NEW(Needed_Entry); 1245 nep->name = dynp->d_un.d_val; 1246 nep->obj = NULL; 1247 nep->next = NULL; 1248 1249 *needed_filtees_tail = nep; 1250 needed_filtees_tail = &nep->next; 1251 1252 if (obj->linkmap.l_refname == NULL) 1253 obj->linkmap.l_refname = (char *)dynp->d_un.d_val; 1254 } 1255 break; 1256 1257 case DT_AUXILIARY: 1258 if (!obj->rtld) { 1259 Needed_Entry *nep = NEW(Needed_Entry); 1260 nep->name = dynp->d_un.d_val; 1261 nep->obj = NULL; 1262 nep->next = NULL; 1263 1264 *needed_aux_filtees_tail = nep; 1265 needed_aux_filtees_tail = &nep->next; 1266 } 1267 break; 1268 1269 case DT_PLTGOT: 1270 obj->pltgot = (Elf_Addr *)(obj->relocbase + dynp->d_un.d_ptr); 1271 break; 1272 1273 case DT_TEXTREL: 1274 obj->textrel = true; 1275 break; 1276 1277 case DT_SYMBOLIC: 1278 obj->symbolic = true; 1279 break; 1280 1281 case DT_RPATH: 1282 /* 1283 * We have to wait until later to process this, because we 1284 * might not have gotten the address of the string table yet. 1285 */ 1286 *dyn_rpath = dynp; 1287 break; 1288 1289 case DT_SONAME: 1290 *dyn_soname = dynp; 1291 break; 1292 1293 case DT_RUNPATH: 1294 *dyn_runpath = dynp; 1295 break; 1296 1297 case DT_INIT: 1298 obj->init = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1299 break; 1300 1301 case DT_PREINIT_ARRAY: 1302 obj->preinit_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1303 break; 1304 1305 case DT_PREINIT_ARRAYSZ: 1306 obj->preinit_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1307 break; 1308 1309 case DT_INIT_ARRAY: 1310 obj->init_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1311 break; 1312 1313 case DT_INIT_ARRAYSZ: 1314 obj->init_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1315 break; 1316 1317 case DT_FINI: 1318 obj->fini = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1319 break; 1320 1321 case DT_FINI_ARRAY: 1322 obj->fini_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1323 break; 1324 1325 case DT_FINI_ARRAYSZ: 1326 obj->fini_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1327 break; 1328 1329 /* 1330 * Don't process DT_DEBUG on MIPS as the dynamic section 1331 * is mapped read-only. DT_MIPS_RLD_MAP is used instead. 1332 */ 1333 1334 #ifndef __mips__ 1335 case DT_DEBUG: 1336 if (!early) 1337 dbg("Filling in DT_DEBUG entry"); 1338 (__DECONST(Elf_Dyn *, dynp))->d_un.d_ptr = (Elf_Addr)&r_debug; 1339 break; 1340 #endif 1341 1342 case DT_FLAGS: 1343 if (dynp->d_un.d_val & DF_ORIGIN) 1344 obj->z_origin = true; 1345 if (dynp->d_un.d_val & DF_SYMBOLIC) 1346 obj->symbolic = true; 1347 if (dynp->d_un.d_val & DF_TEXTREL) 1348 obj->textrel = true; 1349 if (dynp->d_un.d_val & DF_BIND_NOW) 1350 obj->bind_now = true; 1351 if (dynp->d_un.d_val & DF_STATIC_TLS) 1352 obj->static_tls = true; 1353 break; 1354 #ifdef __mips__ 1355 case DT_MIPS_LOCAL_GOTNO: 1356 obj->local_gotno = dynp->d_un.d_val; 1357 break; 1358 1359 case DT_MIPS_SYMTABNO: 1360 obj->symtabno = dynp->d_un.d_val; 1361 break; 1362 1363 case DT_MIPS_GOTSYM: 1364 obj->gotsym = dynp->d_un.d_val; 1365 break; 1366 1367 case DT_MIPS_RLD_MAP: 1368 *((Elf_Addr *)(dynp->d_un.d_ptr)) = (Elf_Addr) &r_debug; 1369 break; 1370 1371 case DT_MIPS_RLD_MAP_REL: 1372 // The MIPS_RLD_MAP_REL tag stores the offset to the .rld_map 1373 // section relative to the address of the tag itself. 1374 *((Elf_Addr *)(__DECONST(char*, dynp) + dynp->d_un.d_val)) = 1375 (Elf_Addr) &r_debug; 1376 break; 1377 1378 case DT_MIPS_PLTGOT: 1379 obj->mips_pltgot = (Elf_Addr *)(obj->relocbase + 1380 dynp->d_un.d_ptr); 1381 break; 1382 1383 #endif 1384 1385 #ifdef __powerpc__ 1386 #ifdef __powerpc64__ 1387 case DT_PPC64_GLINK: 1388 obj->glink = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1389 break; 1390 #else 1391 case DT_PPC_GOT: 1392 obj->gotptr = (Elf_Addr *)(obj->relocbase + dynp->d_un.d_ptr); 1393 break; 1394 #endif 1395 #endif 1396 1397 case DT_FLAGS_1: 1398 if (dynp->d_un.d_val & DF_1_NOOPEN) 1399 obj->z_noopen = true; 1400 if (dynp->d_un.d_val & DF_1_ORIGIN) 1401 obj->z_origin = true; 1402 if (dynp->d_un.d_val & DF_1_GLOBAL) 1403 obj->z_global = true; 1404 if (dynp->d_un.d_val & DF_1_BIND_NOW) 1405 obj->bind_now = true; 1406 if (dynp->d_un.d_val & DF_1_NODELETE) 1407 obj->z_nodelete = true; 1408 if (dynp->d_un.d_val & DF_1_LOADFLTR) 1409 obj->z_loadfltr = true; 1410 if (dynp->d_un.d_val & DF_1_INTERPOSE) 1411 obj->z_interpose = true; 1412 if (dynp->d_un.d_val & DF_1_NODEFLIB) 1413 obj->z_nodeflib = true; 1414 if (dynp->d_un.d_val & DF_1_PIE) 1415 obj->z_pie = true; 1416 break; 1417 1418 default: 1419 if (!early) { 1420 dbg("Ignoring d_tag %ld = %#lx", (long)dynp->d_tag, 1421 (long)dynp->d_tag); 1422 } 1423 break; 1424 } 1425 } 1426 1427 obj->traced = false; 1428 1429 if (plttype == DT_RELA) { 1430 obj->pltrela = (const Elf_Rela *) obj->pltrel; 1431 obj->pltrel = NULL; 1432 obj->pltrelasize = obj->pltrelsize; 1433 obj->pltrelsize = 0; 1434 } 1435 1436 /* Determine size of dynsym table (equal to nchains of sysv hash) */ 1437 if (obj->valid_hash_sysv) 1438 obj->dynsymcount = obj->nchains; 1439 else if (obj->valid_hash_gnu) { 1440 obj->dynsymcount = 0; 1441 for (bkt = 0; bkt < obj->nbuckets_gnu; bkt++) { 1442 if (obj->buckets_gnu[bkt] == 0) 1443 continue; 1444 hashval = &obj->chain_zero_gnu[obj->buckets_gnu[bkt]]; 1445 do 1446 obj->dynsymcount++; 1447 while ((*hashval++ & 1u) == 0); 1448 } 1449 obj->dynsymcount += obj->symndx_gnu; 1450 } 1451 1452 if (obj->linkmap.l_refname != NULL) 1453 obj->linkmap.l_refname = obj->strtab + (unsigned long)obj-> 1454 linkmap.l_refname; 1455 } 1456 1457 static bool 1458 obj_resolve_origin(Obj_Entry *obj) 1459 { 1460 1461 if (obj->origin_path != NULL) 1462 return (true); 1463 obj->origin_path = xmalloc(PATH_MAX); 1464 return (rtld_dirname_abs(obj->path, obj->origin_path) != -1); 1465 } 1466 1467 static bool 1468 digest_dynamic2(Obj_Entry *obj, const Elf_Dyn *dyn_rpath, 1469 const Elf_Dyn *dyn_soname, const Elf_Dyn *dyn_runpath) 1470 { 1471 1472 if (obj->z_origin && !obj_resolve_origin(obj)) 1473 return (false); 1474 1475 if (dyn_runpath != NULL) { 1476 obj->runpath = (const char *)obj->strtab + dyn_runpath->d_un.d_val; 1477 obj->runpath = origin_subst(obj, obj->runpath); 1478 } else if (dyn_rpath != NULL) { 1479 obj->rpath = (const char *)obj->strtab + dyn_rpath->d_un.d_val; 1480 obj->rpath = origin_subst(obj, obj->rpath); 1481 } 1482 if (dyn_soname != NULL) 1483 object_add_name(obj, obj->strtab + dyn_soname->d_un.d_val); 1484 return (true); 1485 } 1486 1487 static bool 1488 digest_dynamic(Obj_Entry *obj, int early) 1489 { 1490 const Elf_Dyn *dyn_rpath; 1491 const Elf_Dyn *dyn_soname; 1492 const Elf_Dyn *dyn_runpath; 1493 1494 digest_dynamic1(obj, early, &dyn_rpath, &dyn_soname, &dyn_runpath); 1495 return (digest_dynamic2(obj, dyn_rpath, dyn_soname, dyn_runpath)); 1496 } 1497 1498 /* 1499 * Process a shared object's program header. This is used only for the 1500 * main program, when the kernel has already loaded the main program 1501 * into memory before calling the dynamic linker. It creates and 1502 * returns an Obj_Entry structure. 1503 */ 1504 static Obj_Entry * 1505 digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path) 1506 { 1507 Obj_Entry *obj; 1508 const Elf_Phdr *phlimit = phdr + phnum; 1509 const Elf_Phdr *ph; 1510 Elf_Addr note_start, note_end; 1511 int nsegs = 0; 1512 1513 obj = obj_new(); 1514 for (ph = phdr; ph < phlimit; ph++) { 1515 if (ph->p_type != PT_PHDR) 1516 continue; 1517 1518 obj->phdr = phdr; 1519 obj->phsize = ph->p_memsz; 1520 obj->relocbase = __DECONST(char *, phdr) - ph->p_vaddr; 1521 break; 1522 } 1523 1524 obj->stack_flags = PF_X | PF_R | PF_W; 1525 1526 for (ph = phdr; ph < phlimit; ph++) { 1527 switch (ph->p_type) { 1528 1529 case PT_INTERP: 1530 obj->interp = (const char *)(ph->p_vaddr + obj->relocbase); 1531 break; 1532 1533 case PT_LOAD: 1534 if (nsegs == 0) { /* First load segment */ 1535 obj->vaddrbase = trunc_page(ph->p_vaddr); 1536 obj->mapbase = obj->vaddrbase + obj->relocbase; 1537 } else { /* Last load segment */ 1538 obj->mapsize = round_page(ph->p_vaddr + ph->p_memsz) - 1539 obj->vaddrbase; 1540 } 1541 nsegs++; 1542 break; 1543 1544 case PT_DYNAMIC: 1545 obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + obj->relocbase); 1546 break; 1547 1548 case PT_TLS: 1549 obj->tlsindex = 1; 1550 obj->tlssize = ph->p_memsz; 1551 obj->tlsalign = ph->p_align; 1552 obj->tlsinitsize = ph->p_filesz; 1553 obj->tlsinit = (void*)(ph->p_vaddr + obj->relocbase); 1554 obj->tlspoffset = ph->p_offset; 1555 break; 1556 1557 case PT_GNU_STACK: 1558 obj->stack_flags = ph->p_flags; 1559 break; 1560 1561 case PT_GNU_RELRO: 1562 obj->relro_page = obj->relocbase + trunc_page(ph->p_vaddr); 1563 obj->relro_size = trunc_page(ph->p_vaddr + ph->p_memsz) - 1564 trunc_page(ph->p_vaddr); 1565 break; 1566 1567 case PT_NOTE: 1568 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; 1569 note_end = note_start + ph->p_filesz; 1570 digest_notes(obj, note_start, note_end); 1571 break; 1572 } 1573 } 1574 if (nsegs < 1) { 1575 _rtld_error("%s: too few PT_LOAD segments", path); 1576 return NULL; 1577 } 1578 1579 obj->entry = entry; 1580 return obj; 1581 } 1582 1583 void 1584 digest_notes(Obj_Entry *obj, Elf_Addr note_start, Elf_Addr note_end) 1585 { 1586 const Elf_Note *note; 1587 const char *note_name; 1588 uintptr_t p; 1589 1590 for (note = (const Elf_Note *)note_start; (Elf_Addr)note < note_end; 1591 note = (const Elf_Note *)((const char *)(note + 1) + 1592 roundup2(note->n_namesz, sizeof(Elf32_Addr)) + 1593 roundup2(note->n_descsz, sizeof(Elf32_Addr)))) { 1594 if (note->n_namesz != sizeof(NOTE_FREEBSD_VENDOR) || 1595 note->n_descsz != sizeof(int32_t)) 1596 continue; 1597 if (note->n_type != NT_FREEBSD_ABI_TAG && 1598 note->n_type != NT_FREEBSD_FEATURE_CTL && 1599 note->n_type != NT_FREEBSD_NOINIT_TAG) 1600 continue; 1601 note_name = (const char *)(note + 1); 1602 if (strncmp(NOTE_FREEBSD_VENDOR, note_name, 1603 sizeof(NOTE_FREEBSD_VENDOR)) != 0) 1604 continue; 1605 switch (note->n_type) { 1606 case NT_FREEBSD_ABI_TAG: 1607 /* FreeBSD osrel note */ 1608 p = (uintptr_t)(note + 1); 1609 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1610 obj->osrel = *(const int32_t *)(p); 1611 dbg("note osrel %d", obj->osrel); 1612 break; 1613 case NT_FREEBSD_FEATURE_CTL: 1614 /* FreeBSD ABI feature control note */ 1615 p = (uintptr_t)(note + 1); 1616 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1617 obj->fctl0 = *(const uint32_t *)(p); 1618 dbg("note fctl0 %#x", obj->fctl0); 1619 break; 1620 case NT_FREEBSD_NOINIT_TAG: 1621 /* FreeBSD 'crt does not call init' note */ 1622 obj->crt_no_init = true; 1623 dbg("note crt_no_init"); 1624 break; 1625 } 1626 } 1627 } 1628 1629 static Obj_Entry * 1630 dlcheck(void *handle) 1631 { 1632 Obj_Entry *obj; 1633 1634 TAILQ_FOREACH(obj, &obj_list, next) { 1635 if (obj == (Obj_Entry *) handle) 1636 break; 1637 } 1638 1639 if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) { 1640 _rtld_error("Invalid shared object handle %p", handle); 1641 return NULL; 1642 } 1643 return obj; 1644 } 1645 1646 /* 1647 * If the given object is already in the donelist, return true. Otherwise 1648 * add the object to the list and return false. 1649 */ 1650 static bool 1651 donelist_check(DoneList *dlp, const Obj_Entry *obj) 1652 { 1653 unsigned int i; 1654 1655 for (i = 0; i < dlp->num_used; i++) 1656 if (dlp->objs[i] == obj) 1657 return true; 1658 /* 1659 * Our donelist allocation should always be sufficient. But if 1660 * our threads locking isn't working properly, more shared objects 1661 * could have been loaded since we allocated the list. That should 1662 * never happen, but we'll handle it properly just in case it does. 1663 */ 1664 if (dlp->num_used < dlp->num_alloc) 1665 dlp->objs[dlp->num_used++] = obj; 1666 return false; 1667 } 1668 1669 /* 1670 * Hash function for symbol table lookup. Don't even think about changing 1671 * this. It is specified by the System V ABI. 1672 */ 1673 unsigned long 1674 elf_hash(const char *name) 1675 { 1676 const unsigned char *p = (const unsigned char *) name; 1677 unsigned long h = 0; 1678 unsigned long g; 1679 1680 while (*p != '\0') { 1681 h = (h << 4) + *p++; 1682 if ((g = h & 0xf0000000) != 0) 1683 h ^= g >> 24; 1684 h &= ~g; 1685 } 1686 return h; 1687 } 1688 1689 /* 1690 * The GNU hash function is the Daniel J. Bernstein hash clipped to 32 bits 1691 * unsigned in case it's implemented with a wider type. 1692 */ 1693 static uint32_t 1694 gnu_hash(const char *s) 1695 { 1696 uint32_t h; 1697 unsigned char c; 1698 1699 h = 5381; 1700 for (c = *s; c != '\0'; c = *++s) 1701 h = h * 33 + c; 1702 return (h & 0xffffffff); 1703 } 1704 1705 1706 /* 1707 * Find the library with the given name, and return its full pathname. 1708 * The returned string is dynamically allocated. Generates an error 1709 * message and returns NULL if the library cannot be found. 1710 * 1711 * If the second argument is non-NULL, then it refers to an already- 1712 * loaded shared object, whose library search path will be searched. 1713 * 1714 * If a library is successfully located via LD_LIBRARY_PATH_FDS, its 1715 * descriptor (which is close-on-exec) will be passed out via the third 1716 * argument. 1717 * 1718 * The search order is: 1719 * DT_RPATH in the referencing file _unless_ DT_RUNPATH is present (1) 1720 * DT_RPATH of the main object if DSO without defined DT_RUNPATH (1) 1721 * LD_LIBRARY_PATH 1722 * DT_RUNPATH in the referencing file 1723 * ldconfig hints (if -z nodefaultlib, filter out default library directories 1724 * from list) 1725 * /lib:/usr/lib _unless_ the referencing file is linked with -z nodefaultlib 1726 * 1727 * (1) Handled in digest_dynamic2 - rpath left NULL if runpath defined. 1728 */ 1729 static char * 1730 find_library(const char *xname, const Obj_Entry *refobj, int *fdp) 1731 { 1732 char *pathname, *refobj_path; 1733 const char *name; 1734 bool nodeflib, objgiven; 1735 1736 objgiven = refobj != NULL; 1737 1738 if (libmap_disable || !objgiven || 1739 (name = lm_find(refobj->path, xname)) == NULL) 1740 name = xname; 1741 1742 if (strchr(name, '/') != NULL) { /* Hard coded pathname */ 1743 if (name[0] != '/' && !trust) { 1744 _rtld_error("Absolute pathname required " 1745 "for shared object \"%s\"", name); 1746 return (NULL); 1747 } 1748 return (origin_subst(__DECONST(Obj_Entry *, refobj), 1749 __DECONST(char *, name))); 1750 } 1751 1752 dbg(" Searching for \"%s\"", name); 1753 refobj_path = objgiven ? refobj->path : NULL; 1754 1755 /* 1756 * If refobj->rpath != NULL, then refobj->runpath is NULL. Fall 1757 * back to pre-conforming behaviour if user requested so with 1758 * LD_LIBRARY_PATH_RPATH environment variable and ignore -z 1759 * nodeflib. 1760 */ 1761 if (objgiven && refobj->rpath != NULL && ld_library_path_rpath) { 1762 pathname = search_library_path(name, ld_library_path, 1763 refobj_path, fdp); 1764 if (pathname != NULL) 1765 return (pathname); 1766 if (refobj != NULL) { 1767 pathname = search_library_path(name, refobj->rpath, 1768 refobj_path, fdp); 1769 if (pathname != NULL) 1770 return (pathname); 1771 } 1772 pathname = search_library_pathfds(name, ld_library_dirs, fdp); 1773 if (pathname != NULL) 1774 return (pathname); 1775 pathname = search_library_path(name, gethints(false), 1776 refobj_path, fdp); 1777 if (pathname != NULL) 1778 return (pathname); 1779 pathname = search_library_path(name, ld_standard_library_path, 1780 refobj_path, fdp); 1781 if (pathname != NULL) 1782 return (pathname); 1783 } else { 1784 nodeflib = objgiven ? refobj->z_nodeflib : false; 1785 if (objgiven) { 1786 pathname = search_library_path(name, refobj->rpath, 1787 refobj->path, fdp); 1788 if (pathname != NULL) 1789 return (pathname); 1790 } 1791 if (objgiven && refobj->runpath == NULL && refobj != obj_main) { 1792 pathname = search_library_path(name, obj_main->rpath, 1793 refobj_path, fdp); 1794 if (pathname != NULL) 1795 return (pathname); 1796 } 1797 pathname = search_library_path(name, ld_library_path, 1798 refobj_path, fdp); 1799 if (pathname != NULL) 1800 return (pathname); 1801 if (objgiven) { 1802 pathname = search_library_path(name, refobj->runpath, 1803 refobj_path, fdp); 1804 if (pathname != NULL) 1805 return (pathname); 1806 } 1807 pathname = search_library_pathfds(name, ld_library_dirs, fdp); 1808 if (pathname != NULL) 1809 return (pathname); 1810 pathname = search_library_path(name, gethints(nodeflib), 1811 refobj_path, fdp); 1812 if (pathname != NULL) 1813 return (pathname); 1814 if (objgiven && !nodeflib) { 1815 pathname = search_library_path(name, 1816 ld_standard_library_path, refobj_path, fdp); 1817 if (pathname != NULL) 1818 return (pathname); 1819 } 1820 } 1821 1822 if (objgiven && refobj->path != NULL) { 1823 _rtld_error("Shared object \"%s\" not found, " 1824 "required by \"%s\"", name, basename(refobj->path)); 1825 } else { 1826 _rtld_error("Shared object \"%s\" not found", name); 1827 } 1828 return (NULL); 1829 } 1830 1831 /* 1832 * Given a symbol number in a referencing object, find the corresponding 1833 * definition of the symbol. Returns a pointer to the symbol, or NULL if 1834 * no definition was found. Returns a pointer to the Obj_Entry of the 1835 * defining object via the reference parameter DEFOBJ_OUT. 1836 */ 1837 const Elf_Sym * 1838 find_symdef(unsigned long symnum, const Obj_Entry *refobj, 1839 const Obj_Entry **defobj_out, int flags, SymCache *cache, 1840 RtldLockState *lockstate) 1841 { 1842 const Elf_Sym *ref; 1843 const Elf_Sym *def; 1844 const Obj_Entry *defobj; 1845 const Ver_Entry *ve; 1846 SymLook req; 1847 const char *name; 1848 int res; 1849 1850 /* 1851 * If we have already found this symbol, get the information from 1852 * the cache. 1853 */ 1854 if (symnum >= refobj->dynsymcount) 1855 return NULL; /* Bad object */ 1856 if (cache != NULL && cache[symnum].sym != NULL) { 1857 *defobj_out = cache[symnum].obj; 1858 return cache[symnum].sym; 1859 } 1860 1861 ref = refobj->symtab + symnum; 1862 name = refobj->strtab + ref->st_name; 1863 def = NULL; 1864 defobj = NULL; 1865 ve = NULL; 1866 1867 /* 1868 * We don't have to do a full scale lookup if the symbol is local. 1869 * We know it will bind to the instance in this load module; to 1870 * which we already have a pointer (ie ref). By not doing a lookup, 1871 * we not only improve performance, but it also avoids unresolvable 1872 * symbols when local symbols are not in the hash table. This has 1873 * been seen with the ia64 toolchain. 1874 */ 1875 if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) { 1876 if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) { 1877 _rtld_error("%s: Bogus symbol table entry %lu", refobj->path, 1878 symnum); 1879 } 1880 symlook_init(&req, name); 1881 req.flags = flags; 1882 ve = req.ventry = fetch_ventry(refobj, symnum); 1883 req.lockstate = lockstate; 1884 res = symlook_default(&req, refobj); 1885 if (res == 0) { 1886 def = req.sym_out; 1887 defobj = req.defobj_out; 1888 } 1889 } else { 1890 def = ref; 1891 defobj = refobj; 1892 } 1893 1894 /* 1895 * If we found no definition and the reference is weak, treat the 1896 * symbol as having the value zero. 1897 */ 1898 if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) { 1899 def = &sym_zero; 1900 defobj = obj_main; 1901 } 1902 1903 if (def != NULL) { 1904 *defobj_out = defobj; 1905 /* Record the information in the cache to avoid subsequent lookups. */ 1906 if (cache != NULL) { 1907 cache[symnum].sym = def; 1908 cache[symnum].obj = defobj; 1909 } 1910 } else { 1911 if (refobj != &obj_rtld) 1912 _rtld_error("%s: Undefined symbol \"%s%s%s\"", refobj->path, name, 1913 ve != NULL ? "@" : "", ve != NULL ? ve->name : ""); 1914 } 1915 return def; 1916 } 1917 1918 /* 1919 * Return the search path from the ldconfig hints file, reading it if 1920 * necessary. If nostdlib is true, then the default search paths are 1921 * not added to result. 1922 * 1923 * Returns NULL if there are problems with the hints file, 1924 * or if the search path there is empty. 1925 */ 1926 static const char * 1927 gethints(bool nostdlib) 1928 { 1929 static char *filtered_path; 1930 static const char *hints; 1931 static struct elfhints_hdr hdr; 1932 struct fill_search_info_args sargs, hargs; 1933 struct dl_serinfo smeta, hmeta, *SLPinfo, *hintinfo; 1934 struct dl_serpath *SLPpath, *hintpath; 1935 char *p; 1936 struct stat hint_stat; 1937 unsigned int SLPndx, hintndx, fndx, fcount; 1938 int fd; 1939 size_t flen; 1940 uint32_t dl; 1941 bool skip; 1942 1943 /* First call, read the hints file */ 1944 if (hints == NULL) { 1945 /* Keep from trying again in case the hints file is bad. */ 1946 hints = ""; 1947 1948 if ((fd = open(ld_elf_hints_path, O_RDONLY | O_CLOEXEC)) == -1) 1949 return (NULL); 1950 1951 /* 1952 * Check of hdr.dirlistlen value against type limit 1953 * intends to pacify static analyzers. Further 1954 * paranoia leads to checks that dirlist is fully 1955 * contained in the file range. 1956 */ 1957 if (read(fd, &hdr, sizeof hdr) != sizeof hdr || 1958 hdr.magic != ELFHINTS_MAGIC || 1959 hdr.version != 1 || hdr.dirlistlen > UINT_MAX / 2 || 1960 fstat(fd, &hint_stat) == -1) { 1961 cleanup1: 1962 close(fd); 1963 hdr.dirlistlen = 0; 1964 return (NULL); 1965 } 1966 dl = hdr.strtab; 1967 if (dl + hdr.dirlist < dl) 1968 goto cleanup1; 1969 dl += hdr.dirlist; 1970 if (dl + hdr.dirlistlen < dl) 1971 goto cleanup1; 1972 dl += hdr.dirlistlen; 1973 if (dl > hint_stat.st_size) 1974 goto cleanup1; 1975 p = xmalloc(hdr.dirlistlen + 1); 1976 if (pread(fd, p, hdr.dirlistlen + 1, 1977 hdr.strtab + hdr.dirlist) != (ssize_t)hdr.dirlistlen + 1 || 1978 p[hdr.dirlistlen] != '\0') { 1979 free(p); 1980 goto cleanup1; 1981 } 1982 hints = p; 1983 close(fd); 1984 } 1985 1986 /* 1987 * If caller agreed to receive list which includes the default 1988 * paths, we are done. Otherwise, if we still did not 1989 * calculated filtered result, do it now. 1990 */ 1991 if (!nostdlib) 1992 return (hints[0] != '\0' ? hints : NULL); 1993 if (filtered_path != NULL) 1994 goto filt_ret; 1995 1996 /* 1997 * Obtain the list of all configured search paths, and the 1998 * list of the default paths. 1999 * 2000 * First estimate the size of the results. 2001 */ 2002 smeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 2003 smeta.dls_cnt = 0; 2004 hmeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 2005 hmeta.dls_cnt = 0; 2006 2007 sargs.request = RTLD_DI_SERINFOSIZE; 2008 sargs.serinfo = &smeta; 2009 hargs.request = RTLD_DI_SERINFOSIZE; 2010 hargs.serinfo = &hmeta; 2011 2012 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 2013 &sargs); 2014 path_enumerate(hints, fill_search_info, NULL, &hargs); 2015 2016 SLPinfo = xmalloc(smeta.dls_size); 2017 hintinfo = xmalloc(hmeta.dls_size); 2018 2019 /* 2020 * Next fetch both sets of paths. 2021 */ 2022 sargs.request = RTLD_DI_SERINFO; 2023 sargs.serinfo = SLPinfo; 2024 sargs.serpath = &SLPinfo->dls_serpath[0]; 2025 sargs.strspace = (char *)&SLPinfo->dls_serpath[smeta.dls_cnt]; 2026 2027 hargs.request = RTLD_DI_SERINFO; 2028 hargs.serinfo = hintinfo; 2029 hargs.serpath = &hintinfo->dls_serpath[0]; 2030 hargs.strspace = (char *)&hintinfo->dls_serpath[hmeta.dls_cnt]; 2031 2032 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 2033 &sargs); 2034 path_enumerate(hints, fill_search_info, NULL, &hargs); 2035 2036 /* 2037 * Now calculate the difference between two sets, by excluding 2038 * standard paths from the full set. 2039 */ 2040 fndx = 0; 2041 fcount = 0; 2042 filtered_path = xmalloc(hdr.dirlistlen + 1); 2043 hintpath = &hintinfo->dls_serpath[0]; 2044 for (hintndx = 0; hintndx < hmeta.dls_cnt; hintndx++, hintpath++) { 2045 skip = false; 2046 SLPpath = &SLPinfo->dls_serpath[0]; 2047 /* 2048 * Check each standard path against current. 2049 */ 2050 for (SLPndx = 0; SLPndx < smeta.dls_cnt; SLPndx++, SLPpath++) { 2051 /* matched, skip the path */ 2052 if (!strcmp(hintpath->dls_name, SLPpath->dls_name)) { 2053 skip = true; 2054 break; 2055 } 2056 } 2057 if (skip) 2058 continue; 2059 /* 2060 * Not matched against any standard path, add the path 2061 * to result. Separate consequtive paths with ':'. 2062 */ 2063 if (fcount > 0) { 2064 filtered_path[fndx] = ':'; 2065 fndx++; 2066 } 2067 fcount++; 2068 flen = strlen(hintpath->dls_name); 2069 strncpy((filtered_path + fndx), hintpath->dls_name, flen); 2070 fndx += flen; 2071 } 2072 filtered_path[fndx] = '\0'; 2073 2074 free(SLPinfo); 2075 free(hintinfo); 2076 2077 filt_ret: 2078 return (filtered_path[0] != '\0' ? filtered_path : NULL); 2079 } 2080 2081 static void 2082 init_dag(Obj_Entry *root) 2083 { 2084 const Needed_Entry *needed; 2085 const Objlist_Entry *elm; 2086 DoneList donelist; 2087 2088 if (root->dag_inited) 2089 return; 2090 donelist_init(&donelist); 2091 2092 /* Root object belongs to own DAG. */ 2093 objlist_push_tail(&root->dldags, root); 2094 objlist_push_tail(&root->dagmembers, root); 2095 donelist_check(&donelist, root); 2096 2097 /* 2098 * Add dependencies of root object to DAG in breadth order 2099 * by exploiting the fact that each new object get added 2100 * to the tail of the dagmembers list. 2101 */ 2102 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2103 for (needed = elm->obj->needed; needed != NULL; needed = needed->next) { 2104 if (needed->obj == NULL || donelist_check(&donelist, needed->obj)) 2105 continue; 2106 objlist_push_tail(&needed->obj->dldags, root); 2107 objlist_push_tail(&root->dagmembers, needed->obj); 2108 } 2109 } 2110 root->dag_inited = true; 2111 } 2112 2113 static void 2114 init_marker(Obj_Entry *marker) 2115 { 2116 2117 bzero(marker, sizeof(*marker)); 2118 marker->marker = true; 2119 } 2120 2121 Obj_Entry * 2122 globallist_curr(const Obj_Entry *obj) 2123 { 2124 2125 for (;;) { 2126 if (obj == NULL) 2127 return (NULL); 2128 if (!obj->marker) 2129 return (__DECONST(Obj_Entry *, obj)); 2130 obj = TAILQ_PREV(obj, obj_entry_q, next); 2131 } 2132 } 2133 2134 Obj_Entry * 2135 globallist_next(const Obj_Entry *obj) 2136 { 2137 2138 for (;;) { 2139 obj = TAILQ_NEXT(obj, next); 2140 if (obj == NULL) 2141 return (NULL); 2142 if (!obj->marker) 2143 return (__DECONST(Obj_Entry *, obj)); 2144 } 2145 } 2146 2147 /* Prevent the object from being unmapped while the bind lock is dropped. */ 2148 static void 2149 hold_object(Obj_Entry *obj) 2150 { 2151 2152 obj->holdcount++; 2153 } 2154 2155 static void 2156 unhold_object(Obj_Entry *obj) 2157 { 2158 2159 assert(obj->holdcount > 0); 2160 if (--obj->holdcount == 0 && obj->unholdfree) 2161 release_object(obj); 2162 } 2163 2164 static void 2165 process_z(Obj_Entry *root) 2166 { 2167 const Objlist_Entry *elm; 2168 Obj_Entry *obj; 2169 2170 /* 2171 * Walk over object DAG and process every dependent object 2172 * that is marked as DF_1_NODELETE or DF_1_GLOBAL. They need 2173 * to grow their own DAG. 2174 * 2175 * For DF_1_GLOBAL, DAG is required for symbol lookups in 2176 * symlook_global() to work. 2177 * 2178 * For DF_1_NODELETE, the DAG should have its reference upped. 2179 */ 2180 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2181 obj = elm->obj; 2182 if (obj == NULL) 2183 continue; 2184 if (obj->z_nodelete && !obj->ref_nodel) { 2185 dbg("obj %s -z nodelete", obj->path); 2186 init_dag(obj); 2187 ref_dag(obj); 2188 obj->ref_nodel = true; 2189 } 2190 if (obj->z_global && objlist_find(&list_global, obj) == NULL) { 2191 dbg("obj %s -z global", obj->path); 2192 objlist_push_tail(&list_global, obj); 2193 init_dag(obj); 2194 } 2195 } 2196 } 2197 2198 static void 2199 parse_rtld_phdr(Obj_Entry *obj) 2200 { 2201 const Elf_Phdr *ph; 2202 Elf_Addr note_start, note_end; 2203 2204 obj->stack_flags = PF_X | PF_R | PF_W; 2205 for (ph = obj->phdr; (const char *)ph < (const char *)obj->phdr + 2206 obj->phsize; ph++) { 2207 switch (ph->p_type) { 2208 case PT_GNU_STACK: 2209 obj->stack_flags = ph->p_flags; 2210 break; 2211 case PT_GNU_RELRO: 2212 obj->relro_page = obj->relocbase + 2213 trunc_page(ph->p_vaddr); 2214 obj->relro_size = round_page(ph->p_memsz); 2215 break; 2216 case PT_NOTE: 2217 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; 2218 note_end = note_start + ph->p_filesz; 2219 digest_notes(obj, note_start, note_end); 2220 break; 2221 } 2222 } 2223 } 2224 2225 /* 2226 * Initialize the dynamic linker. The argument is the address at which 2227 * the dynamic linker has been mapped into memory. The primary task of 2228 * this function is to relocate the dynamic linker. 2229 */ 2230 static void 2231 init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info) 2232 { 2233 Obj_Entry objtmp; /* Temporary rtld object */ 2234 const Elf_Ehdr *ehdr; 2235 const Elf_Dyn *dyn_rpath; 2236 const Elf_Dyn *dyn_soname; 2237 const Elf_Dyn *dyn_runpath; 2238 2239 #ifdef RTLD_INIT_PAGESIZES_EARLY 2240 /* The page size is required by the dynamic memory allocator. */ 2241 init_pagesizes(aux_info); 2242 #endif 2243 2244 /* 2245 * Conjure up an Obj_Entry structure for the dynamic linker. 2246 * 2247 * The "path" member can't be initialized yet because string constants 2248 * cannot yet be accessed. Below we will set it correctly. 2249 */ 2250 memset(&objtmp, 0, sizeof(objtmp)); 2251 objtmp.path = NULL; 2252 objtmp.rtld = true; 2253 objtmp.mapbase = mapbase; 2254 #ifdef PIC 2255 objtmp.relocbase = mapbase; 2256 #endif 2257 2258 objtmp.dynamic = rtld_dynamic(&objtmp); 2259 digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname, &dyn_runpath); 2260 assert(objtmp.needed == NULL); 2261 #if !defined(__mips__) 2262 /* MIPS has a bogus DT_TEXTREL. */ 2263 assert(!objtmp.textrel); 2264 #endif 2265 /* 2266 * Temporarily put the dynamic linker entry into the object list, so 2267 * that symbols can be found. 2268 */ 2269 relocate_objects(&objtmp, true, &objtmp, 0, NULL); 2270 2271 ehdr = (Elf_Ehdr *)mapbase; 2272 objtmp.phdr = (Elf_Phdr *)((char *)mapbase + ehdr->e_phoff); 2273 objtmp.phsize = ehdr->e_phnum * sizeof(objtmp.phdr[0]); 2274 2275 /* Initialize the object list. */ 2276 TAILQ_INIT(&obj_list); 2277 2278 /* Now that non-local variables can be accesses, copy out obj_rtld. */ 2279 memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld)); 2280 2281 #ifndef RTLD_INIT_PAGESIZES_EARLY 2282 /* The page size is required by the dynamic memory allocator. */ 2283 init_pagesizes(aux_info); 2284 #endif 2285 2286 if (aux_info[AT_OSRELDATE] != NULL) 2287 osreldate = aux_info[AT_OSRELDATE]->a_un.a_val; 2288 2289 digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname, dyn_runpath); 2290 2291 /* Replace the path with a dynamically allocated copy. */ 2292 obj_rtld.path = xstrdup(ld_path_rtld); 2293 2294 parse_rtld_phdr(&obj_rtld); 2295 if (obj_enforce_relro(&obj_rtld) == -1) 2296 rtld_die(); 2297 2298 r_debug.r_version = R_DEBUG_VERSION; 2299 r_debug.r_brk = r_debug_state; 2300 r_debug.r_state = RT_CONSISTENT; 2301 r_debug.r_ldbase = obj_rtld.relocbase; 2302 } 2303 2304 /* 2305 * Retrieve the array of supported page sizes. The kernel provides the page 2306 * sizes in increasing order. 2307 */ 2308 static void 2309 init_pagesizes(Elf_Auxinfo **aux_info) 2310 { 2311 static size_t psa[MAXPAGESIZES]; 2312 int mib[2]; 2313 size_t len, size; 2314 2315 if (aux_info[AT_PAGESIZES] != NULL && aux_info[AT_PAGESIZESLEN] != 2316 NULL) { 2317 size = aux_info[AT_PAGESIZESLEN]->a_un.a_val; 2318 pagesizes = aux_info[AT_PAGESIZES]->a_un.a_ptr; 2319 } else { 2320 len = 2; 2321 if (sysctlnametomib("hw.pagesizes", mib, &len) == 0) 2322 size = sizeof(psa); 2323 else { 2324 /* As a fallback, retrieve the base page size. */ 2325 size = sizeof(psa[0]); 2326 if (aux_info[AT_PAGESZ] != NULL) { 2327 psa[0] = aux_info[AT_PAGESZ]->a_un.a_val; 2328 goto psa_filled; 2329 } else { 2330 mib[0] = CTL_HW; 2331 mib[1] = HW_PAGESIZE; 2332 len = 2; 2333 } 2334 } 2335 if (sysctl(mib, len, psa, &size, NULL, 0) == -1) { 2336 _rtld_error("sysctl for hw.pagesize(s) failed"); 2337 rtld_die(); 2338 } 2339 psa_filled: 2340 pagesizes = psa; 2341 } 2342 npagesizes = size / sizeof(pagesizes[0]); 2343 /* Discard any invalid entries at the end of the array. */ 2344 while (npagesizes > 0 && pagesizes[npagesizes - 1] == 0) 2345 npagesizes--; 2346 } 2347 2348 /* 2349 * Add the init functions from a needed object list (and its recursive 2350 * needed objects) to "list". This is not used directly; it is a helper 2351 * function for initlist_add_objects(). The write lock must be held 2352 * when this function is called. 2353 */ 2354 static void 2355 initlist_add_neededs(Needed_Entry *needed, Objlist *list) 2356 { 2357 /* Recursively process the successor needed objects. */ 2358 if (needed->next != NULL) 2359 initlist_add_neededs(needed->next, list); 2360 2361 /* Process the current needed object. */ 2362 if (needed->obj != NULL) 2363 initlist_add_objects(needed->obj, needed->obj, list); 2364 } 2365 2366 /* 2367 * Scan all of the DAGs rooted in the range of objects from "obj" to 2368 * "tail" and add their init functions to "list". This recurses over 2369 * the DAGs and ensure the proper init ordering such that each object's 2370 * needed libraries are initialized before the object itself. At the 2371 * same time, this function adds the objects to the global finalization 2372 * list "list_fini" in the opposite order. The write lock must be 2373 * held when this function is called. 2374 */ 2375 static void 2376 initlist_add_objects(Obj_Entry *obj, Obj_Entry *tail, Objlist *list) 2377 { 2378 Obj_Entry *nobj; 2379 2380 if (obj->init_scanned || obj->init_done) 2381 return; 2382 obj->init_scanned = true; 2383 2384 /* Recursively process the successor objects. */ 2385 nobj = globallist_next(obj); 2386 if (nobj != NULL && obj != tail) 2387 initlist_add_objects(nobj, tail, list); 2388 2389 /* Recursively process the needed objects. */ 2390 if (obj->needed != NULL) 2391 initlist_add_neededs(obj->needed, list); 2392 if (obj->needed_filtees != NULL) 2393 initlist_add_neededs(obj->needed_filtees, list); 2394 if (obj->needed_aux_filtees != NULL) 2395 initlist_add_neededs(obj->needed_aux_filtees, list); 2396 2397 /* Add the object to the init list. */ 2398 objlist_push_tail(list, obj); 2399 2400 /* Add the object to the global fini list in the reverse order. */ 2401 if ((obj->fini != (Elf_Addr)NULL || obj->fini_array != (Elf_Addr)NULL) 2402 && !obj->on_fini_list) { 2403 objlist_push_head(&list_fini, obj); 2404 obj->on_fini_list = true; 2405 } 2406 } 2407 2408 #ifndef FPTR_TARGET 2409 #define FPTR_TARGET(f) ((Elf_Addr) (f)) 2410 #endif 2411 2412 static void 2413 free_needed_filtees(Needed_Entry *n, RtldLockState *lockstate) 2414 { 2415 Needed_Entry *needed, *needed1; 2416 2417 for (needed = n; needed != NULL; needed = needed->next) { 2418 if (needed->obj != NULL) { 2419 dlclose_locked(needed->obj, lockstate); 2420 needed->obj = NULL; 2421 } 2422 } 2423 for (needed = n; needed != NULL; needed = needed1) { 2424 needed1 = needed->next; 2425 free(needed); 2426 } 2427 } 2428 2429 static void 2430 unload_filtees(Obj_Entry *obj, RtldLockState *lockstate) 2431 { 2432 2433 free_needed_filtees(obj->needed_filtees, lockstate); 2434 obj->needed_filtees = NULL; 2435 free_needed_filtees(obj->needed_aux_filtees, lockstate); 2436 obj->needed_aux_filtees = NULL; 2437 obj->filtees_loaded = false; 2438 } 2439 2440 static void 2441 load_filtee1(Obj_Entry *obj, Needed_Entry *needed, int flags, 2442 RtldLockState *lockstate) 2443 { 2444 2445 for (; needed != NULL; needed = needed->next) { 2446 needed->obj = dlopen_object(obj->strtab + needed->name, -1, obj, 2447 flags, ((ld_loadfltr || obj->z_loadfltr) ? RTLD_NOW : RTLD_LAZY) | 2448 RTLD_LOCAL, lockstate); 2449 } 2450 } 2451 2452 static void 2453 load_filtees(Obj_Entry *obj, int flags, RtldLockState *lockstate) 2454 { 2455 2456 lock_restart_for_upgrade(lockstate); 2457 if (!obj->filtees_loaded) { 2458 load_filtee1(obj, obj->needed_filtees, flags, lockstate); 2459 load_filtee1(obj, obj->needed_aux_filtees, flags, lockstate); 2460 obj->filtees_loaded = true; 2461 } 2462 } 2463 2464 static int 2465 process_needed(Obj_Entry *obj, Needed_Entry *needed, int flags) 2466 { 2467 Obj_Entry *obj1; 2468 2469 for (; needed != NULL; needed = needed->next) { 2470 obj1 = needed->obj = load_object(obj->strtab + needed->name, -1, obj, 2471 flags & ~RTLD_LO_NOLOAD); 2472 if (obj1 == NULL && !ld_tracing && (flags & RTLD_LO_FILTEES) == 0) 2473 return (-1); 2474 } 2475 return (0); 2476 } 2477 2478 /* 2479 * Given a shared object, traverse its list of needed objects, and load 2480 * each of them. Returns 0 on success. Generates an error message and 2481 * returns -1 on failure. 2482 */ 2483 static int 2484 load_needed_objects(Obj_Entry *first, int flags) 2485 { 2486 Obj_Entry *obj; 2487 2488 for (obj = first; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 2489 if (obj->marker) 2490 continue; 2491 if (process_needed(obj, obj->needed, flags) == -1) 2492 return (-1); 2493 } 2494 return (0); 2495 } 2496 2497 static int 2498 load_preload_objects(char *p, bool isfd) 2499 { 2500 Obj_Entry *obj; 2501 static const char delim[] = " \t:;"; 2502 2503 if (p == NULL) 2504 return (0); 2505 2506 p += strspn(p, delim); 2507 while (*p != '\0') { 2508 const char *name; 2509 size_t len = strcspn(p, delim); 2510 char savech; 2511 int fd; 2512 2513 savech = p[len]; 2514 p[len] = '\0'; 2515 if (isfd) { 2516 name = NULL; 2517 fd = parse_integer(p); 2518 if (fd == -1) 2519 return (-1); 2520 } else { 2521 name = p; 2522 fd = -1; 2523 } 2524 2525 obj = load_object(name, fd, NULL, 0); 2526 if (obj == NULL) 2527 return (-1); /* XXX - cleanup */ 2528 obj->z_interpose = true; 2529 p[len] = savech; 2530 p += len; 2531 p += strspn(p, delim); 2532 } 2533 LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL); 2534 2535 return (0); 2536 } 2537 2538 static const char * 2539 printable_path(const char *path) 2540 { 2541 2542 return (path == NULL ? "<unknown>" : path); 2543 } 2544 2545 /* 2546 * Load a shared object into memory, if it is not already loaded. The 2547 * object may be specified by name or by user-supplied file descriptor 2548 * fd_u. In the later case, the fd_u descriptor is not closed, but its 2549 * duplicate is. 2550 * 2551 * Returns a pointer to the Obj_Entry for the object. Returns NULL 2552 * on failure. 2553 */ 2554 static Obj_Entry * 2555 load_object(const char *name, int fd_u, const Obj_Entry *refobj, int flags) 2556 { 2557 Obj_Entry *obj; 2558 int fd; 2559 struct stat sb; 2560 char *path; 2561 2562 fd = -1; 2563 if (name != NULL) { 2564 TAILQ_FOREACH(obj, &obj_list, next) { 2565 if (obj->marker || obj->doomed) 2566 continue; 2567 if (object_match_name(obj, name)) 2568 return (obj); 2569 } 2570 2571 path = find_library(name, refobj, &fd); 2572 if (path == NULL) 2573 return (NULL); 2574 } else 2575 path = NULL; 2576 2577 if (fd >= 0) { 2578 /* 2579 * search_library_pathfds() opens a fresh file descriptor for the 2580 * library, so there is no need to dup(). 2581 */ 2582 } else if (fd_u == -1) { 2583 /* 2584 * If we didn't find a match by pathname, or the name is not 2585 * supplied, open the file and check again by device and inode. 2586 * This avoids false mismatches caused by multiple links or ".." 2587 * in pathnames. 2588 * 2589 * To avoid a race, we open the file and use fstat() rather than 2590 * using stat(). 2591 */ 2592 if ((fd = open(path, O_RDONLY | O_CLOEXEC | O_VERIFY)) == -1) { 2593 _rtld_error("Cannot open \"%s\"", path); 2594 free(path); 2595 return (NULL); 2596 } 2597 } else { 2598 fd = fcntl(fd_u, F_DUPFD_CLOEXEC, 0); 2599 if (fd == -1) { 2600 _rtld_error("Cannot dup fd"); 2601 free(path); 2602 return (NULL); 2603 } 2604 } 2605 if (fstat(fd, &sb) == -1) { 2606 _rtld_error("Cannot fstat \"%s\"", printable_path(path)); 2607 close(fd); 2608 free(path); 2609 return NULL; 2610 } 2611 TAILQ_FOREACH(obj, &obj_list, next) { 2612 if (obj->marker || obj->doomed) 2613 continue; 2614 if (obj->ino == sb.st_ino && obj->dev == sb.st_dev) 2615 break; 2616 } 2617 if (obj != NULL && name != NULL) { 2618 object_add_name(obj, name); 2619 free(path); 2620 close(fd); 2621 return obj; 2622 } 2623 if (flags & RTLD_LO_NOLOAD) { 2624 free(path); 2625 close(fd); 2626 return (NULL); 2627 } 2628 2629 /* First use of this object, so we must map it in */ 2630 obj = do_load_object(fd, name, path, &sb, flags); 2631 if (obj == NULL) 2632 free(path); 2633 close(fd); 2634 2635 return obj; 2636 } 2637 2638 static Obj_Entry * 2639 do_load_object(int fd, const char *name, char *path, struct stat *sbp, 2640 int flags) 2641 { 2642 Obj_Entry *obj; 2643 struct statfs fs; 2644 2645 /* 2646 * but first, make sure that environment variables haven't been 2647 * used to circumvent the noexec flag on a filesystem. 2648 */ 2649 if (dangerous_ld_env) { 2650 if (fstatfs(fd, &fs) != 0) { 2651 _rtld_error("Cannot fstatfs \"%s\"", printable_path(path)); 2652 return NULL; 2653 } 2654 if (fs.f_flags & MNT_NOEXEC) { 2655 _rtld_error("Cannot execute objects on %s", fs.f_mntonname); 2656 return NULL; 2657 } 2658 } 2659 dbg("loading \"%s\"", printable_path(path)); 2660 obj = map_object(fd, printable_path(path), sbp); 2661 if (obj == NULL) 2662 return NULL; 2663 2664 /* 2665 * If DT_SONAME is present in the object, digest_dynamic2 already 2666 * added it to the object names. 2667 */ 2668 if (name != NULL) 2669 object_add_name(obj, name); 2670 obj->path = path; 2671 if (!digest_dynamic(obj, 0)) 2672 goto errp; 2673 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", obj->path, 2674 obj->valid_hash_sysv, obj->valid_hash_gnu, obj->dynsymcount); 2675 if (obj->z_pie && (flags & RTLD_LO_TRACE) == 0) { 2676 dbg("refusing to load PIE executable \"%s\"", obj->path); 2677 _rtld_error("Cannot load PIE binary %s as DSO", obj->path); 2678 goto errp; 2679 } 2680 if (obj->z_noopen && (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) == 2681 RTLD_LO_DLOPEN) { 2682 dbg("refusing to load non-loadable \"%s\"", obj->path); 2683 _rtld_error("Cannot dlopen non-loadable %s", obj->path); 2684 goto errp; 2685 } 2686 2687 obj->dlopened = (flags & RTLD_LO_DLOPEN) != 0; 2688 TAILQ_INSERT_TAIL(&obj_list, obj, next); 2689 obj_count++; 2690 obj_loads++; 2691 linkmap_add(obj); /* for GDB & dlinfo() */ 2692 max_stack_flags |= obj->stack_flags; 2693 2694 dbg(" %p .. %p: %s", obj->mapbase, 2695 obj->mapbase + obj->mapsize - 1, obj->path); 2696 if (obj->textrel) 2697 dbg(" WARNING: %s has impure text", obj->path); 2698 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 2699 obj->path); 2700 2701 return (obj); 2702 2703 errp: 2704 munmap(obj->mapbase, obj->mapsize); 2705 obj_free(obj); 2706 return (NULL); 2707 } 2708 2709 Obj_Entry * 2710 obj_from_addr(const void *addr) 2711 { 2712 Obj_Entry *obj; 2713 2714 TAILQ_FOREACH(obj, &obj_list, next) { 2715 if (obj->marker) 2716 continue; 2717 if (addr < (void *) obj->mapbase) 2718 continue; 2719 if (addr < (void *)(obj->mapbase + obj->mapsize)) 2720 return obj; 2721 } 2722 return NULL; 2723 } 2724 2725 static void 2726 preinit_main(void) 2727 { 2728 Elf_Addr *preinit_addr; 2729 int index; 2730 2731 preinit_addr = (Elf_Addr *)obj_main->preinit_array; 2732 if (preinit_addr == NULL) 2733 return; 2734 2735 for (index = 0; index < obj_main->preinit_array_num; index++) { 2736 if (preinit_addr[index] != 0 && preinit_addr[index] != 1) { 2737 dbg("calling preinit function for %s at %p", obj_main->path, 2738 (void *)preinit_addr[index]); 2739 LD_UTRACE(UTRACE_INIT_CALL, obj_main, (void *)preinit_addr[index], 2740 0, 0, obj_main->path); 2741 call_init_pointer(obj_main, preinit_addr[index]); 2742 } 2743 } 2744 } 2745 2746 /* 2747 * Call the finalization functions for each of the objects in "list" 2748 * belonging to the DAG of "root" and referenced once. If NULL "root" 2749 * is specified, every finalization function will be called regardless 2750 * of the reference count and the list elements won't be freed. All of 2751 * the objects are expected to have non-NULL fini functions. 2752 */ 2753 static void 2754 objlist_call_fini(Objlist *list, Obj_Entry *root, RtldLockState *lockstate) 2755 { 2756 Objlist_Entry *elm; 2757 struct dlerror_save *saved_msg; 2758 Elf_Addr *fini_addr; 2759 int index; 2760 2761 assert(root == NULL || root->refcount == 1); 2762 2763 if (root != NULL) 2764 root->doomed = true; 2765 2766 /* 2767 * Preserve the current error message since a fini function might 2768 * call into the dynamic linker and overwrite it. 2769 */ 2770 saved_msg = errmsg_save(); 2771 do { 2772 STAILQ_FOREACH(elm, list, link) { 2773 if (root != NULL && (elm->obj->refcount != 1 || 2774 objlist_find(&root->dagmembers, elm->obj) == NULL)) 2775 continue; 2776 /* Remove object from fini list to prevent recursive invocation. */ 2777 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 2778 /* Ensure that new references cannot be acquired. */ 2779 elm->obj->doomed = true; 2780 2781 hold_object(elm->obj); 2782 lock_release(rtld_bind_lock, lockstate); 2783 /* 2784 * It is legal to have both DT_FINI and DT_FINI_ARRAY defined. 2785 * When this happens, DT_FINI_ARRAY is processed first. 2786 */ 2787 fini_addr = (Elf_Addr *)elm->obj->fini_array; 2788 if (fini_addr != NULL && elm->obj->fini_array_num > 0) { 2789 for (index = elm->obj->fini_array_num - 1; index >= 0; 2790 index--) { 2791 if (fini_addr[index] != 0 && fini_addr[index] != 1) { 2792 dbg("calling fini function for %s at %p", 2793 elm->obj->path, (void *)fini_addr[index]); 2794 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, 2795 (void *)fini_addr[index], 0, 0, elm->obj->path); 2796 call_initfini_pointer(elm->obj, fini_addr[index]); 2797 } 2798 } 2799 } 2800 if (elm->obj->fini != (Elf_Addr)NULL) { 2801 dbg("calling fini function for %s at %p", elm->obj->path, 2802 (void *)elm->obj->fini); 2803 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, (void *)elm->obj->fini, 2804 0, 0, elm->obj->path); 2805 call_initfini_pointer(elm->obj, elm->obj->fini); 2806 } 2807 wlock_acquire(rtld_bind_lock, lockstate); 2808 unhold_object(elm->obj); 2809 /* No need to free anything if process is going down. */ 2810 if (root != NULL) 2811 free(elm); 2812 /* 2813 * We must restart the list traversal after every fini call 2814 * because a dlclose() call from the fini function or from 2815 * another thread might have modified the reference counts. 2816 */ 2817 break; 2818 } 2819 } while (elm != NULL); 2820 errmsg_restore(saved_msg); 2821 } 2822 2823 /* 2824 * Call the initialization functions for each of the objects in 2825 * "list". All of the objects are expected to have non-NULL init 2826 * functions. 2827 */ 2828 static void 2829 objlist_call_init(Objlist *list, RtldLockState *lockstate) 2830 { 2831 Objlist_Entry *elm; 2832 Obj_Entry *obj; 2833 struct dlerror_save *saved_msg; 2834 Elf_Addr *init_addr; 2835 void (*reg)(void (*)(void)); 2836 int index; 2837 2838 /* 2839 * Clean init_scanned flag so that objects can be rechecked and 2840 * possibly initialized earlier if any of vectors called below 2841 * cause the change by using dlopen. 2842 */ 2843 TAILQ_FOREACH(obj, &obj_list, next) { 2844 if (obj->marker) 2845 continue; 2846 obj->init_scanned = false; 2847 } 2848 2849 /* 2850 * Preserve the current error message since an init function might 2851 * call into the dynamic linker and overwrite it. 2852 */ 2853 saved_msg = errmsg_save(); 2854 STAILQ_FOREACH(elm, list, link) { 2855 if (elm->obj->init_done) /* Initialized early. */ 2856 continue; 2857 /* 2858 * Race: other thread might try to use this object before current 2859 * one completes the initialization. Not much can be done here 2860 * without better locking. 2861 */ 2862 elm->obj->init_done = true; 2863 hold_object(elm->obj); 2864 reg = NULL; 2865 if (elm->obj == obj_main && obj_main->crt_no_init) { 2866 reg = (void (*)(void (*)(void)))get_program_var_addr( 2867 "__libc_atexit", lockstate); 2868 } 2869 lock_release(rtld_bind_lock, lockstate); 2870 if (reg != NULL) { 2871 reg(rtld_exit); 2872 rtld_exit_ptr = rtld_nop_exit; 2873 } 2874 2875 /* 2876 * It is legal to have both DT_INIT and DT_INIT_ARRAY defined. 2877 * When this happens, DT_INIT is processed first. 2878 */ 2879 if (elm->obj->init != (Elf_Addr)NULL) { 2880 dbg("calling init function for %s at %p", elm->obj->path, 2881 (void *)elm->obj->init); 2882 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, (void *)elm->obj->init, 2883 0, 0, elm->obj->path); 2884 call_init_pointer(elm->obj, elm->obj->init); 2885 } 2886 init_addr = (Elf_Addr *)elm->obj->init_array; 2887 if (init_addr != NULL) { 2888 for (index = 0; index < elm->obj->init_array_num; index++) { 2889 if (init_addr[index] != 0 && init_addr[index] != 1) { 2890 dbg("calling init function for %s at %p", elm->obj->path, 2891 (void *)init_addr[index]); 2892 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, 2893 (void *)init_addr[index], 0, 0, elm->obj->path); 2894 call_init_pointer(elm->obj, init_addr[index]); 2895 } 2896 } 2897 } 2898 wlock_acquire(rtld_bind_lock, lockstate); 2899 unhold_object(elm->obj); 2900 } 2901 errmsg_restore(saved_msg); 2902 } 2903 2904 static void 2905 objlist_clear(Objlist *list) 2906 { 2907 Objlist_Entry *elm; 2908 2909 while (!STAILQ_EMPTY(list)) { 2910 elm = STAILQ_FIRST(list); 2911 STAILQ_REMOVE_HEAD(list, link); 2912 free(elm); 2913 } 2914 } 2915 2916 static Objlist_Entry * 2917 objlist_find(Objlist *list, const Obj_Entry *obj) 2918 { 2919 Objlist_Entry *elm; 2920 2921 STAILQ_FOREACH(elm, list, link) 2922 if (elm->obj == obj) 2923 return elm; 2924 return NULL; 2925 } 2926 2927 static void 2928 objlist_init(Objlist *list) 2929 { 2930 STAILQ_INIT(list); 2931 } 2932 2933 static void 2934 objlist_push_head(Objlist *list, Obj_Entry *obj) 2935 { 2936 Objlist_Entry *elm; 2937 2938 elm = NEW(Objlist_Entry); 2939 elm->obj = obj; 2940 STAILQ_INSERT_HEAD(list, elm, link); 2941 } 2942 2943 static void 2944 objlist_push_tail(Objlist *list, Obj_Entry *obj) 2945 { 2946 Objlist_Entry *elm; 2947 2948 elm = NEW(Objlist_Entry); 2949 elm->obj = obj; 2950 STAILQ_INSERT_TAIL(list, elm, link); 2951 } 2952 2953 static void 2954 objlist_put_after(Objlist *list, Obj_Entry *listobj, Obj_Entry *obj) 2955 { 2956 Objlist_Entry *elm, *listelm; 2957 2958 STAILQ_FOREACH(listelm, list, link) { 2959 if (listelm->obj == listobj) 2960 break; 2961 } 2962 elm = NEW(Objlist_Entry); 2963 elm->obj = obj; 2964 if (listelm != NULL) 2965 STAILQ_INSERT_AFTER(list, listelm, elm, link); 2966 else 2967 STAILQ_INSERT_TAIL(list, elm, link); 2968 } 2969 2970 static void 2971 objlist_remove(Objlist *list, Obj_Entry *obj) 2972 { 2973 Objlist_Entry *elm; 2974 2975 if ((elm = objlist_find(list, obj)) != NULL) { 2976 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 2977 free(elm); 2978 } 2979 } 2980 2981 /* 2982 * Relocate dag rooted in the specified object. 2983 * Returns 0 on success, or -1 on failure. 2984 */ 2985 2986 static int 2987 relocate_object_dag(Obj_Entry *root, bool bind_now, Obj_Entry *rtldobj, 2988 int flags, RtldLockState *lockstate) 2989 { 2990 Objlist_Entry *elm; 2991 int error; 2992 2993 error = 0; 2994 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2995 error = relocate_object(elm->obj, bind_now, rtldobj, flags, 2996 lockstate); 2997 if (error == -1) 2998 break; 2999 } 3000 return (error); 3001 } 3002 3003 /* 3004 * Prepare for, or clean after, relocating an object marked with 3005 * DT_TEXTREL or DF_TEXTREL. Before relocating, all read-only 3006 * segments are remapped read-write. After relocations are done, the 3007 * segment's permissions are returned back to the modes specified in 3008 * the phdrs. If any relocation happened, or always for wired 3009 * program, COW is triggered. 3010 */ 3011 static int 3012 reloc_textrel_prot(Obj_Entry *obj, bool before) 3013 { 3014 const Elf_Phdr *ph; 3015 void *base; 3016 size_t l, sz; 3017 int prot; 3018 3019 for (l = obj->phsize / sizeof(*ph), ph = obj->phdr; l > 0; 3020 l--, ph++) { 3021 if (ph->p_type != PT_LOAD || (ph->p_flags & PF_W) != 0) 3022 continue; 3023 base = obj->relocbase + trunc_page(ph->p_vaddr); 3024 sz = round_page(ph->p_vaddr + ph->p_filesz) - 3025 trunc_page(ph->p_vaddr); 3026 prot = before ? (PROT_READ | PROT_WRITE) : 3027 convert_prot(ph->p_flags); 3028 if (mprotect(base, sz, prot) == -1) { 3029 _rtld_error("%s: Cannot write-%sable text segment: %s", 3030 obj->path, before ? "en" : "dis", 3031 rtld_strerror(errno)); 3032 return (-1); 3033 } 3034 } 3035 return (0); 3036 } 3037 3038 /* 3039 * Relocate single object. 3040 * Returns 0 on success, or -1 on failure. 3041 */ 3042 static int 3043 relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, 3044 int flags, RtldLockState *lockstate) 3045 { 3046 3047 if (obj->relocated) 3048 return (0); 3049 obj->relocated = true; 3050 if (obj != rtldobj) 3051 dbg("relocating \"%s\"", obj->path); 3052 3053 if (obj->symtab == NULL || obj->strtab == NULL || 3054 !(obj->valid_hash_sysv || obj->valid_hash_gnu)) 3055 dbg("object %s has no run-time symbol table", obj->path); 3056 3057 /* There are relocations to the write-protected text segment. */ 3058 if (obj->textrel && reloc_textrel_prot(obj, true) != 0) 3059 return (-1); 3060 3061 /* Process the non-PLT non-IFUNC relocations. */ 3062 if (reloc_non_plt(obj, rtldobj, flags, lockstate)) 3063 return (-1); 3064 3065 /* Re-protected the text segment. */ 3066 if (obj->textrel && reloc_textrel_prot(obj, false) != 0) 3067 return (-1); 3068 3069 /* Set the special PLT or GOT entries. */ 3070 init_pltgot(obj); 3071 3072 /* Process the PLT relocations. */ 3073 if (reloc_plt(obj, flags, lockstate) == -1) 3074 return (-1); 3075 /* Relocate the jump slots if we are doing immediate binding. */ 3076 if ((obj->bind_now || bind_now) && reloc_jmpslots(obj, flags, 3077 lockstate) == -1) 3078 return (-1); 3079 3080 if (!obj->mainprog && obj_enforce_relro(obj) == -1) 3081 return (-1); 3082 3083 /* 3084 * Set up the magic number and version in the Obj_Entry. These 3085 * were checked in the crt1.o from the original ElfKit, so we 3086 * set them for backward compatibility. 3087 */ 3088 obj->magic = RTLD_MAGIC; 3089 obj->version = RTLD_VERSION; 3090 3091 return (0); 3092 } 3093 3094 /* 3095 * Relocate newly-loaded shared objects. The argument is a pointer to 3096 * the Obj_Entry for the first such object. All objects from the first 3097 * to the end of the list of objects are relocated. Returns 0 on success, 3098 * or -1 on failure. 3099 */ 3100 static int 3101 relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj, 3102 int flags, RtldLockState *lockstate) 3103 { 3104 Obj_Entry *obj; 3105 int error; 3106 3107 for (error = 0, obj = first; obj != NULL; 3108 obj = TAILQ_NEXT(obj, next)) { 3109 if (obj->marker) 3110 continue; 3111 error = relocate_object(obj, bind_now, rtldobj, flags, 3112 lockstate); 3113 if (error == -1) 3114 break; 3115 } 3116 return (error); 3117 } 3118 3119 /* 3120 * The handling of R_MACHINE_IRELATIVE relocations and jumpslots 3121 * referencing STT_GNU_IFUNC symbols is postponed till the other 3122 * relocations are done. The indirect functions specified as 3123 * ifunc are allowed to call other symbols, so we need to have 3124 * objects relocated before asking for resolution from indirects. 3125 * 3126 * The R_MACHINE_IRELATIVE slots are resolved in greedy fashion, 3127 * instead of the usual lazy handling of PLT slots. It is 3128 * consistent with how GNU does it. 3129 */ 3130 static int 3131 resolve_object_ifunc(Obj_Entry *obj, bool bind_now, int flags, 3132 RtldLockState *lockstate) 3133 { 3134 3135 if (obj->ifuncs_resolved) 3136 return (0); 3137 obj->ifuncs_resolved = true; 3138 if (!obj->irelative && !obj->irelative_nonplt && 3139 !((obj->bind_now || bind_now) && obj->gnu_ifunc) && 3140 !obj->non_plt_gnu_ifunc) 3141 return (0); 3142 if (obj_disable_relro(obj) == -1 || 3143 (obj->irelative && reloc_iresolve(obj, lockstate) == -1) || 3144 (obj->irelative_nonplt && reloc_iresolve_nonplt(obj, 3145 lockstate) == -1) || 3146 ((obj->bind_now || bind_now) && obj->gnu_ifunc && 3147 reloc_gnu_ifunc(obj, flags, lockstate) == -1) || 3148 (obj->non_plt_gnu_ifunc && reloc_non_plt(obj, &obj_rtld, 3149 flags | SYMLOOK_IFUNC, lockstate) == -1) || 3150 obj_enforce_relro(obj) == -1) 3151 return (-1); 3152 return (0); 3153 } 3154 3155 static int 3156 initlist_objects_ifunc(Objlist *list, bool bind_now, int flags, 3157 RtldLockState *lockstate) 3158 { 3159 Objlist_Entry *elm; 3160 Obj_Entry *obj; 3161 3162 STAILQ_FOREACH(elm, list, link) { 3163 obj = elm->obj; 3164 if (obj->marker) 3165 continue; 3166 if (resolve_object_ifunc(obj, bind_now, flags, 3167 lockstate) == -1) 3168 return (-1); 3169 } 3170 return (0); 3171 } 3172 3173 /* 3174 * Cleanup procedure. It will be called (by the atexit mechanism) just 3175 * before the process exits. 3176 */ 3177 static void 3178 rtld_exit(void) 3179 { 3180 RtldLockState lockstate; 3181 3182 wlock_acquire(rtld_bind_lock, &lockstate); 3183 dbg("rtld_exit()"); 3184 objlist_call_fini(&list_fini, NULL, &lockstate); 3185 /* No need to remove the items from the list, since we are exiting. */ 3186 if (!libmap_disable) 3187 lm_fini(); 3188 lock_release(rtld_bind_lock, &lockstate); 3189 } 3190 3191 static void 3192 rtld_nop_exit(void) 3193 { 3194 } 3195 3196 /* 3197 * Iterate over a search path, translate each element, and invoke the 3198 * callback on the result. 3199 */ 3200 static void * 3201 path_enumerate(const char *path, path_enum_proc callback, 3202 const char *refobj_path, void *arg) 3203 { 3204 const char *trans; 3205 if (path == NULL) 3206 return (NULL); 3207 3208 path += strspn(path, ":;"); 3209 while (*path != '\0') { 3210 size_t len; 3211 char *res; 3212 3213 len = strcspn(path, ":;"); 3214 trans = lm_findn(refobj_path, path, len); 3215 if (trans) 3216 res = callback(trans, strlen(trans), arg); 3217 else 3218 res = callback(path, len, arg); 3219 3220 if (res != NULL) 3221 return (res); 3222 3223 path += len; 3224 path += strspn(path, ":;"); 3225 } 3226 3227 return (NULL); 3228 } 3229 3230 struct try_library_args { 3231 const char *name; 3232 size_t namelen; 3233 char *buffer; 3234 size_t buflen; 3235 int fd; 3236 }; 3237 3238 static void * 3239 try_library_path(const char *dir, size_t dirlen, void *param) 3240 { 3241 struct try_library_args *arg; 3242 int fd; 3243 3244 arg = param; 3245 if (*dir == '/' || trust) { 3246 char *pathname; 3247 3248 if (dirlen + 1 + arg->namelen + 1 > arg->buflen) 3249 return (NULL); 3250 3251 pathname = arg->buffer; 3252 strncpy(pathname, dir, dirlen); 3253 pathname[dirlen] = '/'; 3254 strcpy(pathname + dirlen + 1, arg->name); 3255 3256 dbg(" Trying \"%s\"", pathname); 3257 fd = open(pathname, O_RDONLY | O_CLOEXEC | O_VERIFY); 3258 if (fd >= 0) { 3259 dbg(" Opened \"%s\", fd %d", pathname, fd); 3260 pathname = xmalloc(dirlen + 1 + arg->namelen + 1); 3261 strcpy(pathname, arg->buffer); 3262 arg->fd = fd; 3263 return (pathname); 3264 } else { 3265 dbg(" Failed to open \"%s\": %s", 3266 pathname, rtld_strerror(errno)); 3267 } 3268 } 3269 return (NULL); 3270 } 3271 3272 static char * 3273 search_library_path(const char *name, const char *path, 3274 const char *refobj_path, int *fdp) 3275 { 3276 char *p; 3277 struct try_library_args arg; 3278 3279 if (path == NULL) 3280 return NULL; 3281 3282 arg.name = name; 3283 arg.namelen = strlen(name); 3284 arg.buffer = xmalloc(PATH_MAX); 3285 arg.buflen = PATH_MAX; 3286 arg.fd = -1; 3287 3288 p = path_enumerate(path, try_library_path, refobj_path, &arg); 3289 *fdp = arg.fd; 3290 3291 free(arg.buffer); 3292 3293 return (p); 3294 } 3295 3296 3297 /* 3298 * Finds the library with the given name using the directory descriptors 3299 * listed in the LD_LIBRARY_PATH_FDS environment variable. 3300 * 3301 * Returns a freshly-opened close-on-exec file descriptor for the library, 3302 * or -1 if the library cannot be found. 3303 */ 3304 static char * 3305 search_library_pathfds(const char *name, const char *path, int *fdp) 3306 { 3307 char *envcopy, *fdstr, *found, *last_token; 3308 size_t len; 3309 int dirfd, fd; 3310 3311 dbg("%s('%s', '%s', fdp)", __func__, name, path); 3312 3313 /* Don't load from user-specified libdirs into setuid binaries. */ 3314 if (!trust) 3315 return (NULL); 3316 3317 /* We can't do anything if LD_LIBRARY_PATH_FDS isn't set. */ 3318 if (path == NULL) 3319 return (NULL); 3320 3321 /* LD_LIBRARY_PATH_FDS only works with relative paths. */ 3322 if (name[0] == '/') { 3323 dbg("Absolute path (%s) passed to %s", name, __func__); 3324 return (NULL); 3325 } 3326 3327 /* 3328 * Use strtok_r() to walk the FD:FD:FD list. This requires a local 3329 * copy of the path, as strtok_r rewrites separator tokens 3330 * with '\0'. 3331 */ 3332 found = NULL; 3333 envcopy = xstrdup(path); 3334 for (fdstr = strtok_r(envcopy, ":", &last_token); fdstr != NULL; 3335 fdstr = strtok_r(NULL, ":", &last_token)) { 3336 dirfd = parse_integer(fdstr); 3337 if (dirfd < 0) { 3338 _rtld_error("failed to parse directory FD: '%s'", 3339 fdstr); 3340 break; 3341 } 3342 fd = __sys_openat(dirfd, name, O_RDONLY | O_CLOEXEC | O_VERIFY); 3343 if (fd >= 0) { 3344 *fdp = fd; 3345 len = strlen(fdstr) + strlen(name) + 3; 3346 found = xmalloc(len); 3347 if (rtld_snprintf(found, len, "#%d/%s", dirfd, name) < 0) { 3348 _rtld_error("error generating '%d/%s'", 3349 dirfd, name); 3350 rtld_die(); 3351 } 3352 dbg("open('%s') => %d", found, fd); 3353 break; 3354 } 3355 } 3356 free(envcopy); 3357 3358 return (found); 3359 } 3360 3361 3362 int 3363 dlclose(void *handle) 3364 { 3365 RtldLockState lockstate; 3366 int error; 3367 3368 wlock_acquire(rtld_bind_lock, &lockstate); 3369 error = dlclose_locked(handle, &lockstate); 3370 lock_release(rtld_bind_lock, &lockstate); 3371 return (error); 3372 } 3373 3374 static int 3375 dlclose_locked(void *handle, RtldLockState *lockstate) 3376 { 3377 Obj_Entry *root; 3378 3379 root = dlcheck(handle); 3380 if (root == NULL) 3381 return -1; 3382 LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount, 3383 root->path); 3384 3385 /* Unreference the object and its dependencies. */ 3386 root->dl_refcount--; 3387 3388 if (root->refcount == 1) { 3389 /* 3390 * The object will be no longer referenced, so we must unload it. 3391 * First, call the fini functions. 3392 */ 3393 objlist_call_fini(&list_fini, root, lockstate); 3394 3395 unref_dag(root); 3396 3397 /* Finish cleaning up the newly-unreferenced objects. */ 3398 GDB_STATE(RT_DELETE,&root->linkmap); 3399 unload_object(root, lockstate); 3400 GDB_STATE(RT_CONSISTENT,NULL); 3401 } else 3402 unref_dag(root); 3403 3404 LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL); 3405 return 0; 3406 } 3407 3408 char * 3409 dlerror(void) 3410 { 3411 if (*(lockinfo.dlerror_seen()) != 0) 3412 return (NULL); 3413 *lockinfo.dlerror_seen() = 1; 3414 return (lockinfo.dlerror_loc()); 3415 } 3416 3417 /* 3418 * This function is deprecated and has no effect. 3419 */ 3420 void 3421 dllockinit(void *context, 3422 void *(*_lock_create)(void *context) __unused, 3423 void (*_rlock_acquire)(void *lock) __unused, 3424 void (*_wlock_acquire)(void *lock) __unused, 3425 void (*_lock_release)(void *lock) __unused, 3426 void (*_lock_destroy)(void *lock) __unused, 3427 void (*context_destroy)(void *context)) 3428 { 3429 static void *cur_context; 3430 static void (*cur_context_destroy)(void *); 3431 3432 /* Just destroy the context from the previous call, if necessary. */ 3433 if (cur_context_destroy != NULL) 3434 cur_context_destroy(cur_context); 3435 cur_context = context; 3436 cur_context_destroy = context_destroy; 3437 } 3438 3439 void * 3440 dlopen(const char *name, int mode) 3441 { 3442 3443 return (rtld_dlopen(name, -1, mode)); 3444 } 3445 3446 void * 3447 fdlopen(int fd, int mode) 3448 { 3449 3450 return (rtld_dlopen(NULL, fd, mode)); 3451 } 3452 3453 static void * 3454 rtld_dlopen(const char *name, int fd, int mode) 3455 { 3456 RtldLockState lockstate; 3457 int lo_flags; 3458 3459 LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name); 3460 ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1"; 3461 if (ld_tracing != NULL) { 3462 rlock_acquire(rtld_bind_lock, &lockstate); 3463 if (sigsetjmp(lockstate.env, 0) != 0) 3464 lock_upgrade(rtld_bind_lock, &lockstate); 3465 environ = __DECONST(char **, *get_program_var_addr("environ", &lockstate)); 3466 lock_release(rtld_bind_lock, &lockstate); 3467 } 3468 lo_flags = RTLD_LO_DLOPEN; 3469 if (mode & RTLD_NODELETE) 3470 lo_flags |= RTLD_LO_NODELETE; 3471 if (mode & RTLD_NOLOAD) 3472 lo_flags |= RTLD_LO_NOLOAD; 3473 if (mode & RTLD_DEEPBIND) 3474 lo_flags |= RTLD_LO_DEEPBIND; 3475 if (ld_tracing != NULL) 3476 lo_flags |= RTLD_LO_TRACE | RTLD_LO_IGNSTLS; 3477 3478 return (dlopen_object(name, fd, obj_main, lo_flags, 3479 mode & (RTLD_MODEMASK | RTLD_GLOBAL), NULL)); 3480 } 3481 3482 static void 3483 dlopen_cleanup(Obj_Entry *obj, RtldLockState *lockstate) 3484 { 3485 3486 obj->dl_refcount--; 3487 unref_dag(obj); 3488 if (obj->refcount == 0) 3489 unload_object(obj, lockstate); 3490 } 3491 3492 static Obj_Entry * 3493 dlopen_object(const char *name, int fd, Obj_Entry *refobj, int lo_flags, 3494 int mode, RtldLockState *lockstate) 3495 { 3496 Obj_Entry *old_obj_tail; 3497 Obj_Entry *obj; 3498 Objlist initlist; 3499 RtldLockState mlockstate; 3500 int result; 3501 3502 dbg("dlopen_object name \"%s\" fd %d refobj \"%s\" lo_flags %#x mode %#x", 3503 name != NULL ? name : "<null>", fd, refobj == NULL ? "<null>" : 3504 refobj->path, lo_flags, mode); 3505 objlist_init(&initlist); 3506 3507 if (lockstate == NULL && !(lo_flags & RTLD_LO_EARLY)) { 3508 wlock_acquire(rtld_bind_lock, &mlockstate); 3509 lockstate = &mlockstate; 3510 } 3511 GDB_STATE(RT_ADD,NULL); 3512 3513 old_obj_tail = globallist_curr(TAILQ_LAST(&obj_list, obj_entry_q)); 3514 obj = NULL; 3515 if (name == NULL && fd == -1) { 3516 obj = obj_main; 3517 obj->refcount++; 3518 } else { 3519 obj = load_object(name, fd, refobj, lo_flags); 3520 } 3521 3522 if (obj) { 3523 obj->dl_refcount++; 3524 if (mode & RTLD_GLOBAL && objlist_find(&list_global, obj) == NULL) 3525 objlist_push_tail(&list_global, obj); 3526 if (globallist_next(old_obj_tail) != NULL) { 3527 /* We loaded something new. */ 3528 assert(globallist_next(old_obj_tail) == obj); 3529 if ((lo_flags & RTLD_LO_DEEPBIND) != 0) 3530 obj->symbolic = true; 3531 result = 0; 3532 if ((lo_flags & (RTLD_LO_EARLY | RTLD_LO_IGNSTLS)) == 0 && 3533 obj->static_tls && !allocate_tls_offset(obj)) { 3534 _rtld_error("%s: No space available " 3535 "for static Thread Local Storage", obj->path); 3536 result = -1; 3537 } 3538 if (result != -1) 3539 result = load_needed_objects(obj, lo_flags & (RTLD_LO_DLOPEN | 3540 RTLD_LO_EARLY | RTLD_LO_IGNSTLS | RTLD_LO_TRACE)); 3541 init_dag(obj); 3542 ref_dag(obj); 3543 if (result != -1) 3544 result = rtld_verify_versions(&obj->dagmembers); 3545 if (result != -1 && ld_tracing) 3546 goto trace; 3547 if (result == -1 || relocate_object_dag(obj, 3548 (mode & RTLD_MODEMASK) == RTLD_NOW, &obj_rtld, 3549 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 3550 lockstate) == -1) { 3551 dlopen_cleanup(obj, lockstate); 3552 obj = NULL; 3553 } else if (lo_flags & RTLD_LO_EARLY) { 3554 /* 3555 * Do not call the init functions for early loaded 3556 * filtees. The image is still not initialized enough 3557 * for them to work. 3558 * 3559 * Our object is found by the global object list and 3560 * will be ordered among all init calls done right 3561 * before transferring control to main. 3562 */ 3563 } else { 3564 /* Make list of init functions to call. */ 3565 initlist_add_objects(obj, obj, &initlist); 3566 } 3567 /* 3568 * Process all no_delete or global objects here, given 3569 * them own DAGs to prevent their dependencies from being 3570 * unloaded. This has to be done after we have loaded all 3571 * of the dependencies, so that we do not miss any. 3572 */ 3573 if (obj != NULL) 3574 process_z(obj); 3575 } else { 3576 /* 3577 * Bump the reference counts for objects on this DAG. If 3578 * this is the first dlopen() call for the object that was 3579 * already loaded as a dependency, initialize the dag 3580 * starting at it. 3581 */ 3582 init_dag(obj); 3583 ref_dag(obj); 3584 3585 if ((lo_flags & RTLD_LO_TRACE) != 0) 3586 goto trace; 3587 } 3588 if (obj != NULL && ((lo_flags & RTLD_LO_NODELETE) != 0 || 3589 obj->z_nodelete) && !obj->ref_nodel) { 3590 dbg("obj %s nodelete", obj->path); 3591 ref_dag(obj); 3592 obj->z_nodelete = obj->ref_nodel = true; 3593 } 3594 } 3595 3596 LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0, 3597 name); 3598 GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL); 3599 3600 if ((lo_flags & RTLD_LO_EARLY) == 0) { 3601 map_stacks_exec(lockstate); 3602 if (obj != NULL) 3603 distribute_static_tls(&initlist, lockstate); 3604 } 3605 3606 if (initlist_objects_ifunc(&initlist, (mode & RTLD_MODEMASK) == RTLD_NOW, 3607 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 3608 lockstate) == -1) { 3609 objlist_clear(&initlist); 3610 dlopen_cleanup(obj, lockstate); 3611 if (lockstate == &mlockstate) 3612 lock_release(rtld_bind_lock, lockstate); 3613 return (NULL); 3614 } 3615 3616 if (!(lo_flags & RTLD_LO_EARLY)) { 3617 /* Call the init functions. */ 3618 objlist_call_init(&initlist, lockstate); 3619 } 3620 objlist_clear(&initlist); 3621 if (lockstate == &mlockstate) 3622 lock_release(rtld_bind_lock, lockstate); 3623 return obj; 3624 trace: 3625 trace_loaded_objects(obj); 3626 if (lockstate == &mlockstate) 3627 lock_release(rtld_bind_lock, lockstate); 3628 exit(0); 3629 } 3630 3631 static void * 3632 do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve, 3633 int flags) 3634 { 3635 DoneList donelist; 3636 const Obj_Entry *obj, *defobj; 3637 const Elf_Sym *def; 3638 SymLook req; 3639 RtldLockState lockstate; 3640 tls_index ti; 3641 void *sym; 3642 int res; 3643 3644 def = NULL; 3645 defobj = NULL; 3646 symlook_init(&req, name); 3647 req.ventry = ve; 3648 req.flags = flags | SYMLOOK_IN_PLT; 3649 req.lockstate = &lockstate; 3650 3651 LD_UTRACE(UTRACE_DLSYM_START, handle, NULL, 0, 0, name); 3652 rlock_acquire(rtld_bind_lock, &lockstate); 3653 if (sigsetjmp(lockstate.env, 0) != 0) 3654 lock_upgrade(rtld_bind_lock, &lockstate); 3655 if (handle == NULL || handle == RTLD_NEXT || 3656 handle == RTLD_DEFAULT || handle == RTLD_SELF) { 3657 3658 if ((obj = obj_from_addr(retaddr)) == NULL) { 3659 _rtld_error("Cannot determine caller's shared object"); 3660 lock_release(rtld_bind_lock, &lockstate); 3661 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 3662 return NULL; 3663 } 3664 if (handle == NULL) { /* Just the caller's shared object. */ 3665 res = symlook_obj(&req, obj); 3666 if (res == 0) { 3667 def = req.sym_out; 3668 defobj = req.defobj_out; 3669 } 3670 } else if (handle == RTLD_NEXT || /* Objects after caller's */ 3671 handle == RTLD_SELF) { /* ... caller included */ 3672 if (handle == RTLD_NEXT) 3673 obj = globallist_next(obj); 3674 for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 3675 if (obj->marker) 3676 continue; 3677 res = symlook_obj(&req, obj); 3678 if (res == 0) { 3679 if (def == NULL || (ld_dynamic_weak && 3680 ELF_ST_BIND(req.sym_out->st_info) != STB_WEAK)) { 3681 def = req.sym_out; 3682 defobj = req.defobj_out; 3683 if (!ld_dynamic_weak || 3684 ELF_ST_BIND(def->st_info) != STB_WEAK) 3685 break; 3686 } 3687 } 3688 } 3689 /* 3690 * Search the dynamic linker itself, and possibly resolve the 3691 * symbol from there. This is how the application links to 3692 * dynamic linker services such as dlopen. 3693 * Note that we ignore ld_dynamic_weak == false case, 3694 * always overriding weak symbols by rtld definitions. 3695 */ 3696 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 3697 res = symlook_obj(&req, &obj_rtld); 3698 if (res == 0) { 3699 def = req.sym_out; 3700 defobj = req.defobj_out; 3701 } 3702 } 3703 } else { 3704 assert(handle == RTLD_DEFAULT); 3705 res = symlook_default(&req, obj); 3706 if (res == 0) { 3707 defobj = req.defobj_out; 3708 def = req.sym_out; 3709 } 3710 } 3711 } else { 3712 if ((obj = dlcheck(handle)) == NULL) { 3713 lock_release(rtld_bind_lock, &lockstate); 3714 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 3715 return NULL; 3716 } 3717 3718 donelist_init(&donelist); 3719 if (obj->mainprog) { 3720 /* Handle obtained by dlopen(NULL, ...) implies global scope. */ 3721 res = symlook_global(&req, &donelist); 3722 if (res == 0) { 3723 def = req.sym_out; 3724 defobj = req.defobj_out; 3725 } 3726 /* 3727 * Search the dynamic linker itself, and possibly resolve the 3728 * symbol from there. This is how the application links to 3729 * dynamic linker services such as dlopen. 3730 */ 3731 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 3732 res = symlook_obj(&req, &obj_rtld); 3733 if (res == 0) { 3734 def = req.sym_out; 3735 defobj = req.defobj_out; 3736 } 3737 } 3738 } 3739 else { 3740 /* Search the whole DAG rooted at the given object. */ 3741 res = symlook_list(&req, &obj->dagmembers, &donelist); 3742 if (res == 0) { 3743 def = req.sym_out; 3744 defobj = req.defobj_out; 3745 } 3746 } 3747 } 3748 3749 if (def != NULL) { 3750 lock_release(rtld_bind_lock, &lockstate); 3751 3752 /* 3753 * The value required by the caller is derived from the value 3754 * of the symbol. this is simply the relocated value of the 3755 * symbol. 3756 */ 3757 if (ELF_ST_TYPE(def->st_info) == STT_FUNC) 3758 sym = make_function_pointer(def, defobj); 3759 else if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 3760 sym = rtld_resolve_ifunc(defobj, def); 3761 else if (ELF_ST_TYPE(def->st_info) == STT_TLS) { 3762 ti.ti_module = defobj->tlsindex; 3763 ti.ti_offset = def->st_value; 3764 sym = __tls_get_addr(&ti); 3765 } else 3766 sym = defobj->relocbase + def->st_value; 3767 LD_UTRACE(UTRACE_DLSYM_STOP, handle, sym, 0, 0, name); 3768 return (sym); 3769 } 3770 3771 _rtld_error("Undefined symbol \"%s%s%s\"", name, ve != NULL ? "@" : "", 3772 ve != NULL ? ve->name : ""); 3773 lock_release(rtld_bind_lock, &lockstate); 3774 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 3775 return NULL; 3776 } 3777 3778 void * 3779 dlsym(void *handle, const char *name) 3780 { 3781 return do_dlsym(handle, name, __builtin_return_address(0), NULL, 3782 SYMLOOK_DLSYM); 3783 } 3784 3785 dlfunc_t 3786 dlfunc(void *handle, const char *name) 3787 { 3788 union { 3789 void *d; 3790 dlfunc_t f; 3791 } rv; 3792 3793 rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL, 3794 SYMLOOK_DLSYM); 3795 return (rv.f); 3796 } 3797 3798 void * 3799 dlvsym(void *handle, const char *name, const char *version) 3800 { 3801 Ver_Entry ventry; 3802 3803 ventry.name = version; 3804 ventry.file = NULL; 3805 ventry.hash = elf_hash(version); 3806 ventry.flags= 0; 3807 return do_dlsym(handle, name, __builtin_return_address(0), &ventry, 3808 SYMLOOK_DLSYM); 3809 } 3810 3811 int 3812 _rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info) 3813 { 3814 const Obj_Entry *obj; 3815 RtldLockState lockstate; 3816 3817 rlock_acquire(rtld_bind_lock, &lockstate); 3818 obj = obj_from_addr(addr); 3819 if (obj == NULL) { 3820 _rtld_error("No shared object contains address"); 3821 lock_release(rtld_bind_lock, &lockstate); 3822 return (0); 3823 } 3824 rtld_fill_dl_phdr_info(obj, phdr_info); 3825 lock_release(rtld_bind_lock, &lockstate); 3826 return (1); 3827 } 3828 3829 int 3830 dladdr(const void *addr, Dl_info *info) 3831 { 3832 const Obj_Entry *obj; 3833 const Elf_Sym *def; 3834 void *symbol_addr; 3835 unsigned long symoffset; 3836 RtldLockState lockstate; 3837 3838 rlock_acquire(rtld_bind_lock, &lockstate); 3839 obj = obj_from_addr(addr); 3840 if (obj == NULL) { 3841 _rtld_error("No shared object contains address"); 3842 lock_release(rtld_bind_lock, &lockstate); 3843 return 0; 3844 } 3845 info->dli_fname = obj->path; 3846 info->dli_fbase = obj->mapbase; 3847 info->dli_saddr = (void *)0; 3848 info->dli_sname = NULL; 3849 3850 /* 3851 * Walk the symbol list looking for the symbol whose address is 3852 * closest to the address sent in. 3853 */ 3854 for (symoffset = 0; symoffset < obj->dynsymcount; symoffset++) { 3855 def = obj->symtab + symoffset; 3856 3857 /* 3858 * For skip the symbol if st_shndx is either SHN_UNDEF or 3859 * SHN_COMMON. 3860 */ 3861 if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON) 3862 continue; 3863 3864 /* 3865 * If the symbol is greater than the specified address, or if it 3866 * is further away from addr than the current nearest symbol, 3867 * then reject it. 3868 */ 3869 symbol_addr = obj->relocbase + def->st_value; 3870 if (symbol_addr > addr || symbol_addr < info->dli_saddr) 3871 continue; 3872 3873 /* Update our idea of the nearest symbol. */ 3874 info->dli_sname = obj->strtab + def->st_name; 3875 info->dli_saddr = symbol_addr; 3876 3877 /* Exact match? */ 3878 if (info->dli_saddr == addr) 3879 break; 3880 } 3881 lock_release(rtld_bind_lock, &lockstate); 3882 return 1; 3883 } 3884 3885 int 3886 dlinfo(void *handle, int request, void *p) 3887 { 3888 const Obj_Entry *obj; 3889 RtldLockState lockstate; 3890 int error; 3891 3892 rlock_acquire(rtld_bind_lock, &lockstate); 3893 3894 if (handle == NULL || handle == RTLD_SELF) { 3895 void *retaddr; 3896 3897 retaddr = __builtin_return_address(0); /* __GNUC__ only */ 3898 if ((obj = obj_from_addr(retaddr)) == NULL) 3899 _rtld_error("Cannot determine caller's shared object"); 3900 } else 3901 obj = dlcheck(handle); 3902 3903 if (obj == NULL) { 3904 lock_release(rtld_bind_lock, &lockstate); 3905 return (-1); 3906 } 3907 3908 error = 0; 3909 switch (request) { 3910 case RTLD_DI_LINKMAP: 3911 *((struct link_map const **)p) = &obj->linkmap; 3912 break; 3913 case RTLD_DI_ORIGIN: 3914 error = rtld_dirname(obj->path, p); 3915 break; 3916 3917 case RTLD_DI_SERINFOSIZE: 3918 case RTLD_DI_SERINFO: 3919 error = do_search_info(obj, request, (struct dl_serinfo *)p); 3920 break; 3921 3922 default: 3923 _rtld_error("Invalid request %d passed to dlinfo()", request); 3924 error = -1; 3925 } 3926 3927 lock_release(rtld_bind_lock, &lockstate); 3928 3929 return (error); 3930 } 3931 3932 static void 3933 rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info) 3934 { 3935 Elf_Addr **dtvp; 3936 3937 phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase; 3938 phdr_info->dlpi_name = obj->path; 3939 phdr_info->dlpi_phdr = obj->phdr; 3940 phdr_info->dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]); 3941 phdr_info->dlpi_tls_modid = obj->tlsindex; 3942 dtvp = _get_tp(); 3943 phdr_info->dlpi_tls_data = (char *)tls_get_addr_slow(dtvp, 3944 obj->tlsindex, 0, true) + TLS_DTV_OFFSET; 3945 phdr_info->dlpi_adds = obj_loads; 3946 phdr_info->dlpi_subs = obj_loads - obj_count; 3947 } 3948 3949 int 3950 dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param) 3951 { 3952 struct dl_phdr_info phdr_info; 3953 Obj_Entry *obj, marker; 3954 RtldLockState bind_lockstate, phdr_lockstate; 3955 int error; 3956 3957 init_marker(&marker); 3958 error = 0; 3959 3960 wlock_acquire(rtld_phdr_lock, &phdr_lockstate); 3961 wlock_acquire(rtld_bind_lock, &bind_lockstate); 3962 for (obj = globallist_curr(TAILQ_FIRST(&obj_list)); obj != NULL;) { 3963 TAILQ_INSERT_AFTER(&obj_list, obj, &marker, next); 3964 rtld_fill_dl_phdr_info(obj, &phdr_info); 3965 hold_object(obj); 3966 lock_release(rtld_bind_lock, &bind_lockstate); 3967 3968 error = callback(&phdr_info, sizeof phdr_info, param); 3969 3970 wlock_acquire(rtld_bind_lock, &bind_lockstate); 3971 unhold_object(obj); 3972 obj = globallist_next(&marker); 3973 TAILQ_REMOVE(&obj_list, &marker, next); 3974 if (error != 0) { 3975 lock_release(rtld_bind_lock, &bind_lockstate); 3976 lock_release(rtld_phdr_lock, &phdr_lockstate); 3977 return (error); 3978 } 3979 } 3980 3981 if (error == 0) { 3982 rtld_fill_dl_phdr_info(&obj_rtld, &phdr_info); 3983 lock_release(rtld_bind_lock, &bind_lockstate); 3984 error = callback(&phdr_info, sizeof(phdr_info), param); 3985 } 3986 lock_release(rtld_phdr_lock, &phdr_lockstate); 3987 return (error); 3988 } 3989 3990 static void * 3991 fill_search_info(const char *dir, size_t dirlen, void *param) 3992 { 3993 struct fill_search_info_args *arg; 3994 3995 arg = param; 3996 3997 if (arg->request == RTLD_DI_SERINFOSIZE) { 3998 arg->serinfo->dls_cnt ++; 3999 arg->serinfo->dls_size += sizeof(struct dl_serpath) + dirlen + 1; 4000 } else { 4001 struct dl_serpath *s_entry; 4002 4003 s_entry = arg->serpath; 4004 s_entry->dls_name = arg->strspace; 4005 s_entry->dls_flags = arg->flags; 4006 4007 strncpy(arg->strspace, dir, dirlen); 4008 arg->strspace[dirlen] = '\0'; 4009 4010 arg->strspace += dirlen + 1; 4011 arg->serpath++; 4012 } 4013 4014 return (NULL); 4015 } 4016 4017 static int 4018 do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info) 4019 { 4020 struct dl_serinfo _info; 4021 struct fill_search_info_args args; 4022 4023 args.request = RTLD_DI_SERINFOSIZE; 4024 args.serinfo = &_info; 4025 4026 _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 4027 _info.dls_cnt = 0; 4028 4029 path_enumerate(obj->rpath, fill_search_info, NULL, &args); 4030 path_enumerate(ld_library_path, fill_search_info, NULL, &args); 4031 path_enumerate(obj->runpath, fill_search_info, NULL, &args); 4032 path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, &args); 4033 if (!obj->z_nodeflib) 4034 path_enumerate(ld_standard_library_path, fill_search_info, NULL, &args); 4035 4036 4037 if (request == RTLD_DI_SERINFOSIZE) { 4038 info->dls_size = _info.dls_size; 4039 info->dls_cnt = _info.dls_cnt; 4040 return (0); 4041 } 4042 4043 if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) { 4044 _rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()"); 4045 return (-1); 4046 } 4047 4048 args.request = RTLD_DI_SERINFO; 4049 args.serinfo = info; 4050 args.serpath = &info->dls_serpath[0]; 4051 args.strspace = (char *)&info->dls_serpath[_info.dls_cnt]; 4052 4053 args.flags = LA_SER_RUNPATH; 4054 if (path_enumerate(obj->rpath, fill_search_info, NULL, &args) != NULL) 4055 return (-1); 4056 4057 args.flags = LA_SER_LIBPATH; 4058 if (path_enumerate(ld_library_path, fill_search_info, NULL, &args) != NULL) 4059 return (-1); 4060 4061 args.flags = LA_SER_RUNPATH; 4062 if (path_enumerate(obj->runpath, fill_search_info, NULL, &args) != NULL) 4063 return (-1); 4064 4065 args.flags = LA_SER_CONFIG; 4066 if (path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, &args) 4067 != NULL) 4068 return (-1); 4069 4070 args.flags = LA_SER_DEFAULT; 4071 if (!obj->z_nodeflib && path_enumerate(ld_standard_library_path, 4072 fill_search_info, NULL, &args) != NULL) 4073 return (-1); 4074 return (0); 4075 } 4076 4077 static int 4078 rtld_dirname(const char *path, char *bname) 4079 { 4080 const char *endp; 4081 4082 /* Empty or NULL string gets treated as "." */ 4083 if (path == NULL || *path == '\0') { 4084 bname[0] = '.'; 4085 bname[1] = '\0'; 4086 return (0); 4087 } 4088 4089 /* Strip trailing slashes */ 4090 endp = path + strlen(path) - 1; 4091 while (endp > path && *endp == '/') 4092 endp--; 4093 4094 /* Find the start of the dir */ 4095 while (endp > path && *endp != '/') 4096 endp--; 4097 4098 /* Either the dir is "/" or there are no slashes */ 4099 if (endp == path) { 4100 bname[0] = *endp == '/' ? '/' : '.'; 4101 bname[1] = '\0'; 4102 return (0); 4103 } else { 4104 do { 4105 endp--; 4106 } while (endp > path && *endp == '/'); 4107 } 4108 4109 if (endp - path + 2 > PATH_MAX) 4110 { 4111 _rtld_error("Filename is too long: %s", path); 4112 return(-1); 4113 } 4114 4115 strncpy(bname, path, endp - path + 1); 4116 bname[endp - path + 1] = '\0'; 4117 return (0); 4118 } 4119 4120 static int 4121 rtld_dirname_abs(const char *path, char *base) 4122 { 4123 char *last; 4124 4125 if (realpath(path, base) == NULL) { 4126 _rtld_error("realpath \"%s\" failed (%s)", path, 4127 rtld_strerror(errno)); 4128 return (-1); 4129 } 4130 dbg("%s -> %s", path, base); 4131 last = strrchr(base, '/'); 4132 if (last == NULL) { 4133 _rtld_error("non-abs result from realpath \"%s\"", path); 4134 return (-1); 4135 } 4136 if (last != base) 4137 *last = '\0'; 4138 return (0); 4139 } 4140 4141 static void 4142 linkmap_add(Obj_Entry *obj) 4143 { 4144 struct link_map *l, *prev; 4145 4146 l = &obj->linkmap; 4147 l->l_name = obj->path; 4148 l->l_base = obj->mapbase; 4149 l->l_ld = obj->dynamic; 4150 l->l_addr = obj->relocbase; 4151 4152 if (r_debug.r_map == NULL) { 4153 r_debug.r_map = l; 4154 return; 4155 } 4156 4157 /* 4158 * Scan to the end of the list, but not past the entry for the 4159 * dynamic linker, which we want to keep at the very end. 4160 */ 4161 for (prev = r_debug.r_map; 4162 prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap; 4163 prev = prev->l_next) 4164 ; 4165 4166 /* Link in the new entry. */ 4167 l->l_prev = prev; 4168 l->l_next = prev->l_next; 4169 if (l->l_next != NULL) 4170 l->l_next->l_prev = l; 4171 prev->l_next = l; 4172 } 4173 4174 static void 4175 linkmap_delete(Obj_Entry *obj) 4176 { 4177 struct link_map *l; 4178 4179 l = &obj->linkmap; 4180 if (l->l_prev == NULL) { 4181 if ((r_debug.r_map = l->l_next) != NULL) 4182 l->l_next->l_prev = NULL; 4183 return; 4184 } 4185 4186 if ((l->l_prev->l_next = l->l_next) != NULL) 4187 l->l_next->l_prev = l->l_prev; 4188 } 4189 4190 /* 4191 * Function for the debugger to set a breakpoint on to gain control. 4192 * 4193 * The two parameters allow the debugger to easily find and determine 4194 * what the runtime loader is doing and to whom it is doing it. 4195 * 4196 * When the loadhook trap is hit (r_debug_state, set at program 4197 * initialization), the arguments can be found on the stack: 4198 * 4199 * +8 struct link_map *m 4200 * +4 struct r_debug *rd 4201 * +0 RetAddr 4202 */ 4203 void 4204 r_debug_state(struct r_debug* rd __unused, struct link_map *m __unused) 4205 { 4206 /* 4207 * The following is a hack to force the compiler to emit calls to 4208 * this function, even when optimizing. If the function is empty, 4209 * the compiler is not obliged to emit any code for calls to it, 4210 * even when marked __noinline. However, gdb depends on those 4211 * calls being made. 4212 */ 4213 __compiler_membar(); 4214 } 4215 4216 /* 4217 * A function called after init routines have completed. This can be used to 4218 * break before a program's entry routine is called, and can be used when 4219 * main is not available in the symbol table. 4220 */ 4221 void 4222 _r_debug_postinit(struct link_map *m __unused) 4223 { 4224 4225 /* See r_debug_state(). */ 4226 __compiler_membar(); 4227 } 4228 4229 static void 4230 release_object(Obj_Entry *obj) 4231 { 4232 4233 if (obj->holdcount > 0) { 4234 obj->unholdfree = true; 4235 return; 4236 } 4237 munmap(obj->mapbase, obj->mapsize); 4238 linkmap_delete(obj); 4239 obj_free(obj); 4240 } 4241 4242 /* 4243 * Get address of the pointer variable in the main program. 4244 * Prefer non-weak symbol over the weak one. 4245 */ 4246 static const void ** 4247 get_program_var_addr(const char *name, RtldLockState *lockstate) 4248 { 4249 SymLook req; 4250 DoneList donelist; 4251 4252 symlook_init(&req, name); 4253 req.lockstate = lockstate; 4254 donelist_init(&donelist); 4255 if (symlook_global(&req, &donelist) != 0) 4256 return (NULL); 4257 if (ELF_ST_TYPE(req.sym_out->st_info) == STT_FUNC) 4258 return ((const void **)make_function_pointer(req.sym_out, 4259 req.defobj_out)); 4260 else if (ELF_ST_TYPE(req.sym_out->st_info) == STT_GNU_IFUNC) 4261 return ((const void **)rtld_resolve_ifunc(req.defobj_out, req.sym_out)); 4262 else 4263 return ((const void **)(req.defobj_out->relocbase + 4264 req.sym_out->st_value)); 4265 } 4266 4267 /* 4268 * Set a pointer variable in the main program to the given value. This 4269 * is used to set key variables such as "environ" before any of the 4270 * init functions are called. 4271 */ 4272 static void 4273 set_program_var(const char *name, const void *value) 4274 { 4275 const void **addr; 4276 4277 if ((addr = get_program_var_addr(name, NULL)) != NULL) { 4278 dbg("\"%s\": *%p <-- %p", name, addr, value); 4279 *addr = value; 4280 } 4281 } 4282 4283 /* 4284 * Search the global objects, including dependencies and main object, 4285 * for the given symbol. 4286 */ 4287 static int 4288 symlook_global(SymLook *req, DoneList *donelist) 4289 { 4290 SymLook req1; 4291 const Objlist_Entry *elm; 4292 int res; 4293 4294 symlook_init_from_req(&req1, req); 4295 4296 /* Search all objects loaded at program start up. */ 4297 if (req->defobj_out == NULL || (ld_dynamic_weak && 4298 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK)) { 4299 res = symlook_list(&req1, &list_main, donelist); 4300 if (res == 0 && (!ld_dynamic_weak || req->defobj_out == NULL || 4301 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4302 req->sym_out = req1.sym_out; 4303 req->defobj_out = req1.defobj_out; 4304 assert(req->defobj_out != NULL); 4305 } 4306 } 4307 4308 /* Search all DAGs whose roots are RTLD_GLOBAL objects. */ 4309 STAILQ_FOREACH(elm, &list_global, link) { 4310 if (req->defobj_out != NULL && (!ld_dynamic_weak || 4311 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK)) 4312 break; 4313 res = symlook_list(&req1, &elm->obj->dagmembers, donelist); 4314 if (res == 0 && (req->defobj_out == NULL || 4315 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4316 req->sym_out = req1.sym_out; 4317 req->defobj_out = req1.defobj_out; 4318 assert(req->defobj_out != NULL); 4319 } 4320 } 4321 4322 return (req->sym_out != NULL ? 0 : ESRCH); 4323 } 4324 4325 /* 4326 * Given a symbol name in a referencing object, find the corresponding 4327 * definition of the symbol. Returns a pointer to the symbol, or NULL if 4328 * no definition was found. Returns a pointer to the Obj_Entry of the 4329 * defining object via the reference parameter DEFOBJ_OUT. 4330 */ 4331 static int 4332 symlook_default(SymLook *req, const Obj_Entry *refobj) 4333 { 4334 DoneList donelist; 4335 const Objlist_Entry *elm; 4336 SymLook req1; 4337 int res; 4338 4339 donelist_init(&donelist); 4340 symlook_init_from_req(&req1, req); 4341 4342 /* 4343 * Look first in the referencing object if linked symbolically, 4344 * and similarly handle protected symbols. 4345 */ 4346 res = symlook_obj(&req1, refobj); 4347 if (res == 0 && (refobj->symbolic || 4348 ELF_ST_VISIBILITY(req1.sym_out->st_other) == STV_PROTECTED)) { 4349 req->sym_out = req1.sym_out; 4350 req->defobj_out = req1.defobj_out; 4351 assert(req->defobj_out != NULL); 4352 } 4353 if (refobj->symbolic || req->defobj_out != NULL) 4354 donelist_check(&donelist, refobj); 4355 4356 symlook_global(req, &donelist); 4357 4358 /* Search all dlopened DAGs containing the referencing object. */ 4359 STAILQ_FOREACH(elm, &refobj->dldags, link) { 4360 if (req->sym_out != NULL && (!ld_dynamic_weak || 4361 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK)) 4362 break; 4363 res = symlook_list(&req1, &elm->obj->dagmembers, &donelist); 4364 if (res == 0 && (req->sym_out == NULL || 4365 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4366 req->sym_out = req1.sym_out; 4367 req->defobj_out = req1.defobj_out; 4368 assert(req->defobj_out != NULL); 4369 } 4370 } 4371 4372 /* 4373 * Search the dynamic linker itself, and possibly resolve the 4374 * symbol from there. This is how the application links to 4375 * dynamic linker services such as dlopen. 4376 */ 4377 if (req->sym_out == NULL || 4378 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 4379 res = symlook_obj(&req1, &obj_rtld); 4380 if (res == 0) { 4381 req->sym_out = req1.sym_out; 4382 req->defobj_out = req1.defobj_out; 4383 assert(req->defobj_out != NULL); 4384 } 4385 } 4386 4387 return (req->sym_out != NULL ? 0 : ESRCH); 4388 } 4389 4390 static int 4391 symlook_list(SymLook *req, const Objlist *objlist, DoneList *dlp) 4392 { 4393 const Elf_Sym *def; 4394 const Obj_Entry *defobj; 4395 const Objlist_Entry *elm; 4396 SymLook req1; 4397 int res; 4398 4399 def = NULL; 4400 defobj = NULL; 4401 STAILQ_FOREACH(elm, objlist, link) { 4402 if (donelist_check(dlp, elm->obj)) 4403 continue; 4404 symlook_init_from_req(&req1, req); 4405 if ((res = symlook_obj(&req1, elm->obj)) == 0) { 4406 if (def == NULL || (ld_dynamic_weak && 4407 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4408 def = req1.sym_out; 4409 defobj = req1.defobj_out; 4410 if (!ld_dynamic_weak || ELF_ST_BIND(def->st_info) != STB_WEAK) 4411 break; 4412 } 4413 } 4414 } 4415 if (def != NULL) { 4416 req->sym_out = def; 4417 req->defobj_out = defobj; 4418 return (0); 4419 } 4420 return (ESRCH); 4421 } 4422 4423 /* 4424 * Search the chain of DAGS cointed to by the given Needed_Entry 4425 * for a symbol of the given name. Each DAG is scanned completely 4426 * before advancing to the next one. Returns a pointer to the symbol, 4427 * or NULL if no definition was found. 4428 */ 4429 static int 4430 symlook_needed(SymLook *req, const Needed_Entry *needed, DoneList *dlp) 4431 { 4432 const Elf_Sym *def; 4433 const Needed_Entry *n; 4434 const Obj_Entry *defobj; 4435 SymLook req1; 4436 int res; 4437 4438 def = NULL; 4439 defobj = NULL; 4440 symlook_init_from_req(&req1, req); 4441 for (n = needed; n != NULL; n = n->next) { 4442 if (n->obj == NULL || 4443 (res = symlook_list(&req1, &n->obj->dagmembers, dlp)) != 0) 4444 continue; 4445 if (def == NULL || (ld_dynamic_weak && 4446 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4447 def = req1.sym_out; 4448 defobj = req1.defobj_out; 4449 if (!ld_dynamic_weak || ELF_ST_BIND(def->st_info) != STB_WEAK) 4450 break; 4451 } 4452 } 4453 if (def != NULL) { 4454 req->sym_out = def; 4455 req->defobj_out = defobj; 4456 return (0); 4457 } 4458 return (ESRCH); 4459 } 4460 4461 /* 4462 * Search the symbol table of a single shared object for a symbol of 4463 * the given name and version, if requested. Returns a pointer to the 4464 * symbol, or NULL if no definition was found. If the object is 4465 * filter, return filtered symbol from filtee. 4466 * 4467 * The symbol's hash value is passed in for efficiency reasons; that 4468 * eliminates many recomputations of the hash value. 4469 */ 4470 int 4471 symlook_obj(SymLook *req, const Obj_Entry *obj) 4472 { 4473 DoneList donelist; 4474 SymLook req1; 4475 int flags, res, mres; 4476 4477 /* 4478 * If there is at least one valid hash at this point, we prefer to 4479 * use the faster GNU version if available. 4480 */ 4481 if (obj->valid_hash_gnu) 4482 mres = symlook_obj1_gnu(req, obj); 4483 else if (obj->valid_hash_sysv) 4484 mres = symlook_obj1_sysv(req, obj); 4485 else 4486 return (EINVAL); 4487 4488 if (mres == 0) { 4489 if (obj->needed_filtees != NULL) { 4490 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; 4491 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 4492 donelist_init(&donelist); 4493 symlook_init_from_req(&req1, req); 4494 res = symlook_needed(&req1, obj->needed_filtees, &donelist); 4495 if (res == 0) { 4496 req->sym_out = req1.sym_out; 4497 req->defobj_out = req1.defobj_out; 4498 } 4499 return (res); 4500 } 4501 if (obj->needed_aux_filtees != NULL) { 4502 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; 4503 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 4504 donelist_init(&donelist); 4505 symlook_init_from_req(&req1, req); 4506 res = symlook_needed(&req1, obj->needed_aux_filtees, &donelist); 4507 if (res == 0) { 4508 req->sym_out = req1.sym_out; 4509 req->defobj_out = req1.defobj_out; 4510 return (res); 4511 } 4512 } 4513 } 4514 return (mres); 4515 } 4516 4517 /* Symbol match routine common to both hash functions */ 4518 static bool 4519 matched_symbol(SymLook *req, const Obj_Entry *obj, Sym_Match_Result *result, 4520 const unsigned long symnum) 4521 { 4522 Elf_Versym verndx; 4523 const Elf_Sym *symp; 4524 const char *strp; 4525 4526 symp = obj->symtab + symnum; 4527 strp = obj->strtab + symp->st_name; 4528 4529 switch (ELF_ST_TYPE(symp->st_info)) { 4530 case STT_FUNC: 4531 case STT_NOTYPE: 4532 case STT_OBJECT: 4533 case STT_COMMON: 4534 case STT_GNU_IFUNC: 4535 if (symp->st_value == 0) 4536 return (false); 4537 /* fallthrough */ 4538 case STT_TLS: 4539 if (symp->st_shndx != SHN_UNDEF) 4540 break; 4541 #ifndef __mips__ 4542 else if (((req->flags & SYMLOOK_IN_PLT) == 0) && 4543 (ELF_ST_TYPE(symp->st_info) == STT_FUNC)) 4544 break; 4545 #endif 4546 /* fallthrough */ 4547 default: 4548 return (false); 4549 } 4550 if (req->name[0] != strp[0] || strcmp(req->name, strp) != 0) 4551 return (false); 4552 4553 if (req->ventry == NULL) { 4554 if (obj->versyms != NULL) { 4555 verndx = VER_NDX(obj->versyms[symnum]); 4556 if (verndx > obj->vernum) { 4557 _rtld_error( 4558 "%s: symbol %s references wrong version %d", 4559 obj->path, obj->strtab + symnum, verndx); 4560 return (false); 4561 } 4562 /* 4563 * If we are not called from dlsym (i.e. this 4564 * is a normal relocation from unversioned 4565 * binary), accept the symbol immediately if 4566 * it happens to have first version after this 4567 * shared object became versioned. Otherwise, 4568 * if symbol is versioned and not hidden, 4569 * remember it. If it is the only symbol with 4570 * this name exported by the shared object, it 4571 * will be returned as a match by the calling 4572 * function. If symbol is global (verndx < 2) 4573 * accept it unconditionally. 4574 */ 4575 if ((req->flags & SYMLOOK_DLSYM) == 0 && 4576 verndx == VER_NDX_GIVEN) { 4577 result->sym_out = symp; 4578 return (true); 4579 } 4580 else if (verndx >= VER_NDX_GIVEN) { 4581 if ((obj->versyms[symnum] & VER_NDX_HIDDEN) 4582 == 0) { 4583 if (result->vsymp == NULL) 4584 result->vsymp = symp; 4585 result->vcount++; 4586 } 4587 return (false); 4588 } 4589 } 4590 result->sym_out = symp; 4591 return (true); 4592 } 4593 if (obj->versyms == NULL) { 4594 if (object_match_name(obj, req->ventry->name)) { 4595 _rtld_error("%s: object %s should provide version %s " 4596 "for symbol %s", obj_rtld.path, obj->path, 4597 req->ventry->name, obj->strtab + symnum); 4598 return (false); 4599 } 4600 } else { 4601 verndx = VER_NDX(obj->versyms[symnum]); 4602 if (verndx > obj->vernum) { 4603 _rtld_error("%s: symbol %s references wrong version %d", 4604 obj->path, obj->strtab + symnum, verndx); 4605 return (false); 4606 } 4607 if (obj->vertab[verndx].hash != req->ventry->hash || 4608 strcmp(obj->vertab[verndx].name, req->ventry->name)) { 4609 /* 4610 * Version does not match. Look if this is a 4611 * global symbol and if it is not hidden. If 4612 * global symbol (verndx < 2) is available, 4613 * use it. Do not return symbol if we are 4614 * called by dlvsym, because dlvsym looks for 4615 * a specific version and default one is not 4616 * what dlvsym wants. 4617 */ 4618 if ((req->flags & SYMLOOK_DLSYM) || 4619 (verndx >= VER_NDX_GIVEN) || 4620 (obj->versyms[symnum] & VER_NDX_HIDDEN)) 4621 return (false); 4622 } 4623 } 4624 result->sym_out = symp; 4625 return (true); 4626 } 4627 4628 /* 4629 * Search for symbol using SysV hash function. 4630 * obj->buckets is known not to be NULL at this point; the test for this was 4631 * performed with the obj->valid_hash_sysv assignment. 4632 */ 4633 static int 4634 symlook_obj1_sysv(SymLook *req, const Obj_Entry *obj) 4635 { 4636 unsigned long symnum; 4637 Sym_Match_Result matchres; 4638 4639 matchres.sym_out = NULL; 4640 matchres.vsymp = NULL; 4641 matchres.vcount = 0; 4642 4643 for (symnum = obj->buckets[req->hash % obj->nbuckets]; 4644 symnum != STN_UNDEF; symnum = obj->chains[symnum]) { 4645 if (symnum >= obj->nchains) 4646 return (ESRCH); /* Bad object */ 4647 4648 if (matched_symbol(req, obj, &matchres, symnum)) { 4649 req->sym_out = matchres.sym_out; 4650 req->defobj_out = obj; 4651 return (0); 4652 } 4653 } 4654 if (matchres.vcount == 1) { 4655 req->sym_out = matchres.vsymp; 4656 req->defobj_out = obj; 4657 return (0); 4658 } 4659 return (ESRCH); 4660 } 4661 4662 /* Search for symbol using GNU hash function */ 4663 static int 4664 symlook_obj1_gnu(SymLook *req, const Obj_Entry *obj) 4665 { 4666 Elf_Addr bloom_word; 4667 const Elf32_Word *hashval; 4668 Elf32_Word bucket; 4669 Sym_Match_Result matchres; 4670 unsigned int h1, h2; 4671 unsigned long symnum; 4672 4673 matchres.sym_out = NULL; 4674 matchres.vsymp = NULL; 4675 matchres.vcount = 0; 4676 4677 /* Pick right bitmask word from Bloom filter array */ 4678 bloom_word = obj->bloom_gnu[(req->hash_gnu / __ELF_WORD_SIZE) & 4679 obj->maskwords_bm_gnu]; 4680 4681 /* Calculate modulus word size of gnu hash and its derivative */ 4682 h1 = req->hash_gnu & (__ELF_WORD_SIZE - 1); 4683 h2 = ((req->hash_gnu >> obj->shift2_gnu) & (__ELF_WORD_SIZE - 1)); 4684 4685 /* Filter out the "definitely not in set" queries */ 4686 if (((bloom_word >> h1) & (bloom_word >> h2) & 1) == 0) 4687 return (ESRCH); 4688 4689 /* Locate hash chain and corresponding value element*/ 4690 bucket = obj->buckets_gnu[req->hash_gnu % obj->nbuckets_gnu]; 4691 if (bucket == 0) 4692 return (ESRCH); 4693 hashval = &obj->chain_zero_gnu[bucket]; 4694 do { 4695 if (((*hashval ^ req->hash_gnu) >> 1) == 0) { 4696 symnum = hashval - obj->chain_zero_gnu; 4697 if (matched_symbol(req, obj, &matchres, symnum)) { 4698 req->sym_out = matchres.sym_out; 4699 req->defobj_out = obj; 4700 return (0); 4701 } 4702 } 4703 } while ((*hashval++ & 1) == 0); 4704 if (matchres.vcount == 1) { 4705 req->sym_out = matchres.vsymp; 4706 req->defobj_out = obj; 4707 return (0); 4708 } 4709 return (ESRCH); 4710 } 4711 4712 static void 4713 trace_loaded_objects(Obj_Entry *obj) 4714 { 4715 const char *fmt1, *fmt2, *fmt, *main_local, *list_containers; 4716 int c; 4717 4718 if ((main_local = getenv(_LD("TRACE_LOADED_OBJECTS_PROGNAME"))) == NULL) 4719 main_local = ""; 4720 4721 if ((fmt1 = getenv(_LD("TRACE_LOADED_OBJECTS_FMT1"))) == NULL) 4722 fmt1 = "\t%o => %p (%x)\n"; 4723 4724 if ((fmt2 = getenv(_LD("TRACE_LOADED_OBJECTS_FMT2"))) == NULL) 4725 fmt2 = "\t%o (%x)\n"; 4726 4727 list_containers = getenv(_LD("TRACE_LOADED_OBJECTS_ALL")); 4728 4729 for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 4730 Needed_Entry *needed; 4731 const char *name, *path; 4732 bool is_lib; 4733 4734 if (obj->marker) 4735 continue; 4736 if (list_containers && obj->needed != NULL) 4737 rtld_printf("%s:\n", obj->path); 4738 for (needed = obj->needed; needed; needed = needed->next) { 4739 if (needed->obj != NULL) { 4740 if (needed->obj->traced && !list_containers) 4741 continue; 4742 needed->obj->traced = true; 4743 path = needed->obj->path; 4744 } else 4745 path = "not found"; 4746 4747 name = obj->strtab + needed->name; 4748 is_lib = strncmp(name, "lib", 3) == 0; /* XXX - bogus */ 4749 4750 fmt = is_lib ? fmt1 : fmt2; 4751 while ((c = *fmt++) != '\0') { 4752 switch (c) { 4753 default: 4754 rtld_putchar(c); 4755 continue; 4756 case '\\': 4757 switch (c = *fmt) { 4758 case '\0': 4759 continue; 4760 case 'n': 4761 rtld_putchar('\n'); 4762 break; 4763 case 't': 4764 rtld_putchar('\t'); 4765 break; 4766 } 4767 break; 4768 case '%': 4769 switch (c = *fmt) { 4770 case '\0': 4771 continue; 4772 case '%': 4773 default: 4774 rtld_putchar(c); 4775 break; 4776 case 'A': 4777 rtld_putstr(main_local); 4778 break; 4779 case 'a': 4780 rtld_putstr(obj_main->path); 4781 break; 4782 case 'o': 4783 rtld_putstr(name); 4784 break; 4785 #if 0 4786 case 'm': 4787 rtld_printf("%d", sodp->sod_major); 4788 break; 4789 case 'n': 4790 rtld_printf("%d", sodp->sod_minor); 4791 break; 4792 #endif 4793 case 'p': 4794 rtld_putstr(path); 4795 break; 4796 case 'x': 4797 rtld_printf("%p", needed->obj ? needed->obj->mapbase : 4798 0); 4799 break; 4800 } 4801 break; 4802 } 4803 ++fmt; 4804 } 4805 } 4806 } 4807 } 4808 4809 /* 4810 * Unload a dlopened object and its dependencies from memory and from 4811 * our data structures. It is assumed that the DAG rooted in the 4812 * object has already been unreferenced, and that the object has a 4813 * reference count of 0. 4814 */ 4815 static void 4816 unload_object(Obj_Entry *root, RtldLockState *lockstate) 4817 { 4818 Obj_Entry marker, *obj, *next; 4819 4820 assert(root->refcount == 0); 4821 4822 /* 4823 * Pass over the DAG removing unreferenced objects from 4824 * appropriate lists. 4825 */ 4826 unlink_object(root); 4827 4828 /* Unmap all objects that are no longer referenced. */ 4829 for (obj = TAILQ_FIRST(&obj_list); obj != NULL; obj = next) { 4830 next = TAILQ_NEXT(obj, next); 4831 if (obj->marker || obj->refcount != 0) 4832 continue; 4833 LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase, 4834 obj->mapsize, 0, obj->path); 4835 dbg("unloading \"%s\"", obj->path); 4836 /* 4837 * Unlink the object now to prevent new references from 4838 * being acquired while the bind lock is dropped in 4839 * recursive dlclose() invocations. 4840 */ 4841 TAILQ_REMOVE(&obj_list, obj, next); 4842 obj_count--; 4843 4844 if (obj->filtees_loaded) { 4845 if (next != NULL) { 4846 init_marker(&marker); 4847 TAILQ_INSERT_BEFORE(next, &marker, next); 4848 unload_filtees(obj, lockstate); 4849 next = TAILQ_NEXT(&marker, next); 4850 TAILQ_REMOVE(&obj_list, &marker, next); 4851 } else 4852 unload_filtees(obj, lockstate); 4853 } 4854 release_object(obj); 4855 } 4856 } 4857 4858 static void 4859 unlink_object(Obj_Entry *root) 4860 { 4861 Objlist_Entry *elm; 4862 4863 if (root->refcount == 0) { 4864 /* Remove the object from the RTLD_GLOBAL list. */ 4865 objlist_remove(&list_global, root); 4866 4867 /* Remove the object from all objects' DAG lists. */ 4868 STAILQ_FOREACH(elm, &root->dagmembers, link) { 4869 objlist_remove(&elm->obj->dldags, root); 4870 if (elm->obj != root) 4871 unlink_object(elm->obj); 4872 } 4873 } 4874 } 4875 4876 static void 4877 ref_dag(Obj_Entry *root) 4878 { 4879 Objlist_Entry *elm; 4880 4881 assert(root->dag_inited); 4882 STAILQ_FOREACH(elm, &root->dagmembers, link) 4883 elm->obj->refcount++; 4884 } 4885 4886 static void 4887 unref_dag(Obj_Entry *root) 4888 { 4889 Objlist_Entry *elm; 4890 4891 assert(root->dag_inited); 4892 STAILQ_FOREACH(elm, &root->dagmembers, link) 4893 elm->obj->refcount--; 4894 } 4895 4896 /* 4897 * Common code for MD __tls_get_addr(). 4898 */ 4899 static void * 4900 tls_get_addr_slow(Elf_Addr **dtvp, int index, size_t offset, bool locked) 4901 { 4902 Elf_Addr *newdtv, *dtv; 4903 RtldLockState lockstate; 4904 int to_copy; 4905 4906 dtv = *dtvp; 4907 /* Check dtv generation in case new modules have arrived */ 4908 if (dtv[0] != tls_dtv_generation) { 4909 if (!locked) 4910 wlock_acquire(rtld_bind_lock, &lockstate); 4911 newdtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4912 to_copy = dtv[1]; 4913 if (to_copy > tls_max_index) 4914 to_copy = tls_max_index; 4915 memcpy(&newdtv[2], &dtv[2], to_copy * sizeof(Elf_Addr)); 4916 newdtv[0] = tls_dtv_generation; 4917 newdtv[1] = tls_max_index; 4918 free(dtv); 4919 if (!locked) 4920 lock_release(rtld_bind_lock, &lockstate); 4921 dtv = *dtvp = newdtv; 4922 } 4923 4924 /* Dynamically allocate module TLS if necessary */ 4925 if (dtv[index + 1] == 0) { 4926 /* Signal safe, wlock will block out signals. */ 4927 if (!locked) 4928 wlock_acquire(rtld_bind_lock, &lockstate); 4929 if (!dtv[index + 1]) 4930 dtv[index + 1] = (Elf_Addr)allocate_module_tls(index); 4931 if (!locked) 4932 lock_release(rtld_bind_lock, &lockstate); 4933 } 4934 return ((void *)(dtv[index + 1] + offset)); 4935 } 4936 4937 void * 4938 tls_get_addr_common(Elf_Addr **dtvp, int index, size_t offset) 4939 { 4940 Elf_Addr *dtv; 4941 4942 dtv = *dtvp; 4943 /* Check dtv generation in case new modules have arrived */ 4944 if (__predict_true(dtv[0] == tls_dtv_generation && 4945 dtv[index + 1] != 0)) 4946 return ((void *)(dtv[index + 1] + offset)); 4947 return (tls_get_addr_slow(dtvp, index, offset, false)); 4948 } 4949 4950 #ifdef TLS_VARIANT_I 4951 4952 /* 4953 * Return pointer to allocated TLS block 4954 */ 4955 static void * 4956 get_tls_block_ptr(void *tcb, size_t tcbsize) 4957 { 4958 size_t extra_size, post_size, pre_size, tls_block_size; 4959 size_t tls_init_align; 4960 4961 tls_init_align = MAX(obj_main->tlsalign, 1); 4962 4963 /* Compute fragments sizes. */ 4964 extra_size = tcbsize - TLS_TCB_SIZE; 4965 post_size = calculate_tls_post_size(tls_init_align); 4966 tls_block_size = tcbsize + post_size; 4967 pre_size = roundup2(tls_block_size, tls_init_align) - tls_block_size; 4968 4969 return ((char *)tcb - pre_size - extra_size); 4970 } 4971 4972 /* 4973 * Allocate Static TLS using the Variant I method. 4974 * 4975 * For details on the layout, see lib/libc/gen/tls.c. 4976 * 4977 * NB: rtld's tls_static_space variable includes TLS_TCB_SIZE and post_size as 4978 * it is based on tls_last_offset, and TLS offsets here are really TCB 4979 * offsets, whereas libc's tls_static_space is just the executable's static 4980 * TLS segment. 4981 */ 4982 void * 4983 allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign) 4984 { 4985 Obj_Entry *obj; 4986 char *tls_block; 4987 Elf_Addr *dtv, **tcb; 4988 Elf_Addr addr; 4989 Elf_Addr i; 4990 size_t extra_size, maxalign, post_size, pre_size, tls_block_size; 4991 size_t tls_init_align, tls_init_offset; 4992 4993 if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE) 4994 return (oldtcb); 4995 4996 assert(tcbsize >= TLS_TCB_SIZE); 4997 maxalign = MAX(tcbalign, tls_static_max_align); 4998 tls_init_align = MAX(obj_main->tlsalign, 1); 4999 5000 /* Compute fragmets sizes. */ 5001 extra_size = tcbsize - TLS_TCB_SIZE; 5002 post_size = calculate_tls_post_size(tls_init_align); 5003 tls_block_size = tcbsize + post_size; 5004 pre_size = roundup2(tls_block_size, tls_init_align) - tls_block_size; 5005 tls_block_size += pre_size + tls_static_space - TLS_TCB_SIZE - post_size; 5006 5007 /* Allocate whole TLS block */ 5008 tls_block = malloc_aligned(tls_block_size, maxalign, 0); 5009 tcb = (Elf_Addr **)(tls_block + pre_size + extra_size); 5010 5011 if (oldtcb != NULL) { 5012 memcpy(tls_block, get_tls_block_ptr(oldtcb, tcbsize), 5013 tls_static_space); 5014 free_aligned(get_tls_block_ptr(oldtcb, tcbsize)); 5015 5016 /* Adjust the DTV. */ 5017 dtv = tcb[0]; 5018 for (i = 0; i < dtv[1]; i++) { 5019 if (dtv[i+2] >= (Elf_Addr)oldtcb && 5020 dtv[i+2] < (Elf_Addr)oldtcb + tls_static_space) { 5021 dtv[i+2] = dtv[i+2] - (Elf_Addr)oldtcb + (Elf_Addr)tcb; 5022 } 5023 } 5024 } else { 5025 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 5026 tcb[0] = dtv; 5027 dtv[0] = tls_dtv_generation; 5028 dtv[1] = tls_max_index; 5029 5030 for (obj = globallist_curr(objs); obj != NULL; 5031 obj = globallist_next(obj)) { 5032 if (obj->tlsoffset == 0) 5033 continue; 5034 tls_init_offset = obj->tlspoffset & (obj->tlsalign - 1); 5035 addr = (Elf_Addr)tcb + obj->tlsoffset; 5036 if (tls_init_offset > 0) 5037 memset((void *)addr, 0, tls_init_offset); 5038 if (obj->tlsinitsize > 0) { 5039 memcpy((void *)(addr + tls_init_offset), obj->tlsinit, 5040 obj->tlsinitsize); 5041 } 5042 if (obj->tlssize > obj->tlsinitsize) { 5043 memset((void *)(addr + tls_init_offset + obj->tlsinitsize), 5044 0, obj->tlssize - obj->tlsinitsize - tls_init_offset); 5045 } 5046 dtv[obj->tlsindex + 1] = addr; 5047 } 5048 } 5049 5050 return (tcb); 5051 } 5052 5053 void 5054 free_tls(void *tcb, size_t tcbsize, size_t tcbalign __unused) 5055 { 5056 Elf_Addr *dtv; 5057 Elf_Addr tlsstart, tlsend; 5058 size_t post_size; 5059 size_t dtvsize, i, tls_init_align; 5060 5061 assert(tcbsize >= TLS_TCB_SIZE); 5062 tls_init_align = MAX(obj_main->tlsalign, 1); 5063 5064 /* Compute fragments sizes. */ 5065 post_size = calculate_tls_post_size(tls_init_align); 5066 5067 tlsstart = (Elf_Addr)tcb + TLS_TCB_SIZE + post_size; 5068 tlsend = (Elf_Addr)tcb + tls_static_space; 5069 5070 dtv = *(Elf_Addr **)tcb; 5071 dtvsize = dtv[1]; 5072 for (i = 0; i < dtvsize; i++) { 5073 if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] >= tlsend)) { 5074 free((void*)dtv[i+2]); 5075 } 5076 } 5077 free(dtv); 5078 free_aligned(get_tls_block_ptr(tcb, tcbsize)); 5079 } 5080 5081 #endif /* TLS_VARIANT_I */ 5082 5083 #ifdef TLS_VARIANT_II 5084 5085 /* 5086 * Allocate Static TLS using the Variant II method. 5087 */ 5088 void * 5089 allocate_tls(Obj_Entry *objs, void *oldtls, size_t tcbsize, size_t tcbalign) 5090 { 5091 Obj_Entry *obj; 5092 size_t size, ralign; 5093 char *tls; 5094 Elf_Addr *dtv, *olddtv; 5095 Elf_Addr segbase, oldsegbase, addr; 5096 size_t i; 5097 5098 ralign = tcbalign; 5099 if (tls_static_max_align > ralign) 5100 ralign = tls_static_max_align; 5101 size = roundup(tls_static_space, ralign) + roundup(tcbsize, ralign); 5102 5103 assert(tcbsize >= 2*sizeof(Elf_Addr)); 5104 tls = malloc_aligned(size, ralign, 0 /* XXX */); 5105 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 5106 5107 segbase = (Elf_Addr)(tls + roundup(tls_static_space, ralign)); 5108 ((Elf_Addr*)segbase)[0] = segbase; 5109 ((Elf_Addr*)segbase)[1] = (Elf_Addr) dtv; 5110 5111 dtv[0] = tls_dtv_generation; 5112 dtv[1] = tls_max_index; 5113 5114 if (oldtls) { 5115 /* 5116 * Copy the static TLS block over whole. 5117 */ 5118 oldsegbase = (Elf_Addr) oldtls; 5119 memcpy((void *)(segbase - tls_static_space), 5120 (const void *)(oldsegbase - tls_static_space), 5121 tls_static_space); 5122 5123 /* 5124 * If any dynamic TLS blocks have been created tls_get_addr(), 5125 * move them over. 5126 */ 5127 olddtv = ((Elf_Addr**)oldsegbase)[1]; 5128 for (i = 0; i < olddtv[1]; i++) { 5129 if (olddtv[i+2] < oldsegbase - size || olddtv[i+2] > oldsegbase) { 5130 dtv[i+2] = olddtv[i+2]; 5131 olddtv[i+2] = 0; 5132 } 5133 } 5134 5135 /* 5136 * We assume that this block was the one we created with 5137 * allocate_initial_tls(). 5138 */ 5139 free_tls(oldtls, 2*sizeof(Elf_Addr), sizeof(Elf_Addr)); 5140 } else { 5141 for (obj = objs; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 5142 if (obj->marker || obj->tlsoffset == 0) 5143 continue; 5144 addr = segbase - obj->tlsoffset; 5145 memset((void*)(addr + obj->tlsinitsize), 5146 0, obj->tlssize - obj->tlsinitsize); 5147 if (obj->tlsinit) { 5148 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize); 5149 obj->static_tls_copied = true; 5150 } 5151 dtv[obj->tlsindex + 1] = addr; 5152 } 5153 } 5154 5155 return (void*) segbase; 5156 } 5157 5158 void 5159 free_tls(void *tls, size_t tcbsize __unused, size_t tcbalign) 5160 { 5161 Elf_Addr* dtv; 5162 size_t size, ralign; 5163 int dtvsize, i; 5164 Elf_Addr tlsstart, tlsend; 5165 5166 /* 5167 * Figure out the size of the initial TLS block so that we can 5168 * find stuff which ___tls_get_addr() allocated dynamically. 5169 */ 5170 ralign = tcbalign; 5171 if (tls_static_max_align > ralign) 5172 ralign = tls_static_max_align; 5173 size = roundup(tls_static_space, ralign); 5174 5175 dtv = ((Elf_Addr**)tls)[1]; 5176 dtvsize = dtv[1]; 5177 tlsend = (Elf_Addr) tls; 5178 tlsstart = tlsend - size; 5179 for (i = 0; i < dtvsize; i++) { 5180 if (dtv[i + 2] != 0 && (dtv[i + 2] < tlsstart || dtv[i + 2] > tlsend)) { 5181 free_aligned((void *)dtv[i + 2]); 5182 } 5183 } 5184 5185 free_aligned((void *)tlsstart); 5186 free((void*) dtv); 5187 } 5188 5189 #endif /* TLS_VARIANT_II */ 5190 5191 /* 5192 * Allocate TLS block for module with given index. 5193 */ 5194 void * 5195 allocate_module_tls(int index) 5196 { 5197 Obj_Entry *obj; 5198 char *p; 5199 5200 TAILQ_FOREACH(obj, &obj_list, next) { 5201 if (obj->marker) 5202 continue; 5203 if (obj->tlsindex == index) 5204 break; 5205 } 5206 if (obj == NULL) { 5207 _rtld_error("Can't find module with TLS index %d", index); 5208 rtld_die(); 5209 } 5210 5211 p = malloc_aligned(obj->tlssize, obj->tlsalign, obj->tlspoffset); 5212 memcpy(p, obj->tlsinit, obj->tlsinitsize); 5213 memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize); 5214 return (p); 5215 } 5216 5217 bool 5218 allocate_tls_offset(Obj_Entry *obj) 5219 { 5220 size_t off; 5221 5222 if (obj->tls_done) 5223 return true; 5224 5225 if (obj->tlssize == 0) { 5226 obj->tls_done = true; 5227 return true; 5228 } 5229 5230 if (tls_last_offset == 0) 5231 off = calculate_first_tls_offset(obj->tlssize, obj->tlsalign, 5232 obj->tlspoffset); 5233 else 5234 off = calculate_tls_offset(tls_last_offset, tls_last_size, 5235 obj->tlssize, obj->tlsalign, obj->tlspoffset); 5236 5237 obj->tlsoffset = off; 5238 #ifdef TLS_VARIANT_I 5239 off += obj->tlssize; 5240 #endif 5241 5242 /* 5243 * If we have already fixed the size of the static TLS block, we 5244 * must stay within that size. When allocating the static TLS, we 5245 * leave a small amount of space spare to be used for dynamically 5246 * loading modules which use static TLS. 5247 */ 5248 if (tls_static_space != 0) { 5249 if (off > tls_static_space) 5250 return false; 5251 } else if (obj->tlsalign > tls_static_max_align) { 5252 tls_static_max_align = obj->tlsalign; 5253 } 5254 5255 tls_last_offset = off; 5256 tls_last_size = obj->tlssize; 5257 obj->tls_done = true; 5258 5259 return true; 5260 } 5261 5262 void 5263 free_tls_offset(Obj_Entry *obj) 5264 { 5265 5266 /* 5267 * If we were the last thing to allocate out of the static TLS 5268 * block, we give our space back to the 'allocator'. This is a 5269 * simplistic workaround to allow libGL.so.1 to be loaded and 5270 * unloaded multiple times. 5271 */ 5272 size_t off = obj->tlsoffset; 5273 #ifdef TLS_VARIANT_I 5274 off += obj->tlssize; 5275 #endif 5276 if (off == tls_last_offset) { 5277 tls_last_offset -= obj->tlssize; 5278 tls_last_size = 0; 5279 } 5280 } 5281 5282 void * 5283 _rtld_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign) 5284 { 5285 void *ret; 5286 RtldLockState lockstate; 5287 5288 wlock_acquire(rtld_bind_lock, &lockstate); 5289 ret = allocate_tls(globallist_curr(TAILQ_FIRST(&obj_list)), oldtls, 5290 tcbsize, tcbalign); 5291 lock_release(rtld_bind_lock, &lockstate); 5292 return (ret); 5293 } 5294 5295 void 5296 _rtld_free_tls(void *tcb, size_t tcbsize, size_t tcbalign) 5297 { 5298 RtldLockState lockstate; 5299 5300 wlock_acquire(rtld_bind_lock, &lockstate); 5301 free_tls(tcb, tcbsize, tcbalign); 5302 lock_release(rtld_bind_lock, &lockstate); 5303 } 5304 5305 static void 5306 object_add_name(Obj_Entry *obj, const char *name) 5307 { 5308 Name_Entry *entry; 5309 size_t len; 5310 5311 len = strlen(name); 5312 entry = malloc(sizeof(Name_Entry) + len); 5313 5314 if (entry != NULL) { 5315 strcpy(entry->name, name); 5316 STAILQ_INSERT_TAIL(&obj->names, entry, link); 5317 } 5318 } 5319 5320 static int 5321 object_match_name(const Obj_Entry *obj, const char *name) 5322 { 5323 Name_Entry *entry; 5324 5325 STAILQ_FOREACH(entry, &obj->names, link) { 5326 if (strcmp(name, entry->name) == 0) 5327 return (1); 5328 } 5329 return (0); 5330 } 5331 5332 static Obj_Entry * 5333 locate_dependency(const Obj_Entry *obj, const char *name) 5334 { 5335 const Objlist_Entry *entry; 5336 const Needed_Entry *needed; 5337 5338 STAILQ_FOREACH(entry, &list_main, link) { 5339 if (object_match_name(entry->obj, name)) 5340 return entry->obj; 5341 } 5342 5343 for (needed = obj->needed; needed != NULL; needed = needed->next) { 5344 if (strcmp(obj->strtab + needed->name, name) == 0 || 5345 (needed->obj != NULL && object_match_name(needed->obj, name))) { 5346 /* 5347 * If there is DT_NEEDED for the name we are looking for, 5348 * we are all set. Note that object might not be found if 5349 * dependency was not loaded yet, so the function can 5350 * return NULL here. This is expected and handled 5351 * properly by the caller. 5352 */ 5353 return (needed->obj); 5354 } 5355 } 5356 _rtld_error("%s: Unexpected inconsistency: dependency %s not found", 5357 obj->path, name); 5358 rtld_die(); 5359 } 5360 5361 static int 5362 check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj, 5363 const Elf_Vernaux *vna) 5364 { 5365 const Elf_Verdef *vd; 5366 const char *vername; 5367 5368 vername = refobj->strtab + vna->vna_name; 5369 vd = depobj->verdef; 5370 if (vd == NULL) { 5371 _rtld_error("%s: version %s required by %s not defined", 5372 depobj->path, vername, refobj->path); 5373 return (-1); 5374 } 5375 for (;;) { 5376 if (vd->vd_version != VER_DEF_CURRENT) { 5377 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 5378 depobj->path, vd->vd_version); 5379 return (-1); 5380 } 5381 if (vna->vna_hash == vd->vd_hash) { 5382 const Elf_Verdaux *aux = (const Elf_Verdaux *) 5383 ((const char *)vd + vd->vd_aux); 5384 if (strcmp(vername, depobj->strtab + aux->vda_name) == 0) 5385 return (0); 5386 } 5387 if (vd->vd_next == 0) 5388 break; 5389 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 5390 } 5391 if (vna->vna_flags & VER_FLG_WEAK) 5392 return (0); 5393 _rtld_error("%s: version %s required by %s not found", 5394 depobj->path, vername, refobj->path); 5395 return (-1); 5396 } 5397 5398 static int 5399 rtld_verify_object_versions(Obj_Entry *obj) 5400 { 5401 const Elf_Verneed *vn; 5402 const Elf_Verdef *vd; 5403 const Elf_Verdaux *vda; 5404 const Elf_Vernaux *vna; 5405 const Obj_Entry *depobj; 5406 int maxvernum, vernum; 5407 5408 if (obj->ver_checked) 5409 return (0); 5410 obj->ver_checked = true; 5411 5412 maxvernum = 0; 5413 /* 5414 * Walk over defined and required version records and figure out 5415 * max index used by any of them. Do very basic sanity checking 5416 * while there. 5417 */ 5418 vn = obj->verneed; 5419 while (vn != NULL) { 5420 if (vn->vn_version != VER_NEED_CURRENT) { 5421 _rtld_error("%s: Unsupported version %d of Elf_Verneed entry", 5422 obj->path, vn->vn_version); 5423 return (-1); 5424 } 5425 vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux); 5426 for (;;) { 5427 vernum = VER_NEED_IDX(vna->vna_other); 5428 if (vernum > maxvernum) 5429 maxvernum = vernum; 5430 if (vna->vna_next == 0) 5431 break; 5432 vna = (const Elf_Vernaux *)((const char *)vna + vna->vna_next); 5433 } 5434 if (vn->vn_next == 0) 5435 break; 5436 vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next); 5437 } 5438 5439 vd = obj->verdef; 5440 while (vd != NULL) { 5441 if (vd->vd_version != VER_DEF_CURRENT) { 5442 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 5443 obj->path, vd->vd_version); 5444 return (-1); 5445 } 5446 vernum = VER_DEF_IDX(vd->vd_ndx); 5447 if (vernum > maxvernum) 5448 maxvernum = vernum; 5449 if (vd->vd_next == 0) 5450 break; 5451 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 5452 } 5453 5454 if (maxvernum == 0) 5455 return (0); 5456 5457 /* 5458 * Store version information in array indexable by version index. 5459 * Verify that object version requirements are satisfied along the 5460 * way. 5461 */ 5462 obj->vernum = maxvernum + 1; 5463 obj->vertab = xcalloc(obj->vernum, sizeof(Ver_Entry)); 5464 5465 vd = obj->verdef; 5466 while (vd != NULL) { 5467 if ((vd->vd_flags & VER_FLG_BASE) == 0) { 5468 vernum = VER_DEF_IDX(vd->vd_ndx); 5469 assert(vernum <= maxvernum); 5470 vda = (const Elf_Verdaux *)((const char *)vd + vd->vd_aux); 5471 obj->vertab[vernum].hash = vd->vd_hash; 5472 obj->vertab[vernum].name = obj->strtab + vda->vda_name; 5473 obj->vertab[vernum].file = NULL; 5474 obj->vertab[vernum].flags = 0; 5475 } 5476 if (vd->vd_next == 0) 5477 break; 5478 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 5479 } 5480 5481 vn = obj->verneed; 5482 while (vn != NULL) { 5483 depobj = locate_dependency(obj, obj->strtab + vn->vn_file); 5484 if (depobj == NULL) 5485 return (-1); 5486 vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux); 5487 for (;;) { 5488 if (check_object_provided_version(obj, depobj, vna)) 5489 return (-1); 5490 vernum = VER_NEED_IDX(vna->vna_other); 5491 assert(vernum <= maxvernum); 5492 obj->vertab[vernum].hash = vna->vna_hash; 5493 obj->vertab[vernum].name = obj->strtab + vna->vna_name; 5494 obj->vertab[vernum].file = obj->strtab + vn->vn_file; 5495 obj->vertab[vernum].flags = (vna->vna_other & VER_NEED_HIDDEN) ? 5496 VER_INFO_HIDDEN : 0; 5497 if (vna->vna_next == 0) 5498 break; 5499 vna = (const Elf_Vernaux *)((const char *)vna + vna->vna_next); 5500 } 5501 if (vn->vn_next == 0) 5502 break; 5503 vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next); 5504 } 5505 return 0; 5506 } 5507 5508 static int 5509 rtld_verify_versions(const Objlist *objlist) 5510 { 5511 Objlist_Entry *entry; 5512 int rc; 5513 5514 rc = 0; 5515 STAILQ_FOREACH(entry, objlist, link) { 5516 /* 5517 * Skip dummy objects or objects that have their version requirements 5518 * already checked. 5519 */ 5520 if (entry->obj->strtab == NULL || entry->obj->vertab != NULL) 5521 continue; 5522 if (rtld_verify_object_versions(entry->obj) == -1) { 5523 rc = -1; 5524 if (ld_tracing == NULL) 5525 break; 5526 } 5527 } 5528 if (rc == 0 || ld_tracing != NULL) 5529 rc = rtld_verify_object_versions(&obj_rtld); 5530 return rc; 5531 } 5532 5533 const Ver_Entry * 5534 fetch_ventry(const Obj_Entry *obj, unsigned long symnum) 5535 { 5536 Elf_Versym vernum; 5537 5538 if (obj->vertab) { 5539 vernum = VER_NDX(obj->versyms[symnum]); 5540 if (vernum >= obj->vernum) { 5541 _rtld_error("%s: symbol %s has wrong verneed value %d", 5542 obj->path, obj->strtab + symnum, vernum); 5543 } else if (obj->vertab[vernum].hash != 0) { 5544 return &obj->vertab[vernum]; 5545 } 5546 } 5547 return NULL; 5548 } 5549 5550 int 5551 _rtld_get_stack_prot(void) 5552 { 5553 5554 return (stack_prot); 5555 } 5556 5557 int 5558 _rtld_is_dlopened(void *arg) 5559 { 5560 Obj_Entry *obj; 5561 RtldLockState lockstate; 5562 int res; 5563 5564 rlock_acquire(rtld_bind_lock, &lockstate); 5565 obj = dlcheck(arg); 5566 if (obj == NULL) 5567 obj = obj_from_addr(arg); 5568 if (obj == NULL) { 5569 _rtld_error("No shared object contains address"); 5570 lock_release(rtld_bind_lock, &lockstate); 5571 return (-1); 5572 } 5573 res = obj->dlopened ? 1 : 0; 5574 lock_release(rtld_bind_lock, &lockstate); 5575 return (res); 5576 } 5577 5578 static int 5579 obj_remap_relro(Obj_Entry *obj, int prot) 5580 { 5581 5582 if (obj->relro_size > 0 && mprotect(obj->relro_page, obj->relro_size, 5583 prot) == -1) { 5584 _rtld_error("%s: Cannot set relro protection to %#x: %s", 5585 obj->path, prot, rtld_strerror(errno)); 5586 return (-1); 5587 } 5588 return (0); 5589 } 5590 5591 static int 5592 obj_disable_relro(Obj_Entry *obj) 5593 { 5594 5595 return (obj_remap_relro(obj, PROT_READ | PROT_WRITE)); 5596 } 5597 5598 static int 5599 obj_enforce_relro(Obj_Entry *obj) 5600 { 5601 5602 return (obj_remap_relro(obj, PROT_READ)); 5603 } 5604 5605 static void 5606 map_stacks_exec(RtldLockState *lockstate) 5607 { 5608 void (*thr_map_stacks_exec)(void); 5609 5610 if ((max_stack_flags & PF_X) == 0 || (stack_prot & PROT_EXEC) != 0) 5611 return; 5612 thr_map_stacks_exec = (void (*)(void))(uintptr_t) 5613 get_program_var_addr("__pthread_map_stacks_exec", lockstate); 5614 if (thr_map_stacks_exec != NULL) { 5615 stack_prot |= PROT_EXEC; 5616 thr_map_stacks_exec(); 5617 } 5618 } 5619 5620 static void 5621 distribute_static_tls(Objlist *list, RtldLockState *lockstate) 5622 { 5623 Objlist_Entry *elm; 5624 Obj_Entry *obj; 5625 void (*distrib)(size_t, void *, size_t, size_t); 5626 5627 distrib = (void (*)(size_t, void *, size_t, size_t))(uintptr_t) 5628 get_program_var_addr("__pthread_distribute_static_tls", lockstate); 5629 if (distrib == NULL) 5630 return; 5631 STAILQ_FOREACH(elm, list, link) { 5632 obj = elm->obj; 5633 if (obj->marker || !obj->tls_done || obj->static_tls_copied) 5634 continue; 5635 distrib(obj->tlsoffset, obj->tlsinit, obj->tlsinitsize, 5636 obj->tlssize); 5637 obj->static_tls_copied = true; 5638 } 5639 } 5640 5641 void 5642 symlook_init(SymLook *dst, const char *name) 5643 { 5644 5645 bzero(dst, sizeof(*dst)); 5646 dst->name = name; 5647 dst->hash = elf_hash(name); 5648 dst->hash_gnu = gnu_hash(name); 5649 } 5650 5651 static void 5652 symlook_init_from_req(SymLook *dst, const SymLook *src) 5653 { 5654 5655 dst->name = src->name; 5656 dst->hash = src->hash; 5657 dst->hash_gnu = src->hash_gnu; 5658 dst->ventry = src->ventry; 5659 dst->flags = src->flags; 5660 dst->defobj_out = NULL; 5661 dst->sym_out = NULL; 5662 dst->lockstate = src->lockstate; 5663 } 5664 5665 static int 5666 open_binary_fd(const char *argv0, bool search_in_path, 5667 const char **binpath_res) 5668 { 5669 char *binpath, *pathenv, *pe, *res1; 5670 const char *res; 5671 int fd; 5672 5673 binpath = NULL; 5674 res = NULL; 5675 if (search_in_path && strchr(argv0, '/') == NULL) { 5676 binpath = xmalloc(PATH_MAX); 5677 pathenv = getenv("PATH"); 5678 if (pathenv == NULL) { 5679 _rtld_error("-p and no PATH environment variable"); 5680 rtld_die(); 5681 } 5682 pathenv = strdup(pathenv); 5683 if (pathenv == NULL) { 5684 _rtld_error("Cannot allocate memory"); 5685 rtld_die(); 5686 } 5687 fd = -1; 5688 errno = ENOENT; 5689 while ((pe = strsep(&pathenv, ":")) != NULL) { 5690 if (strlcpy(binpath, pe, PATH_MAX) >= PATH_MAX) 5691 continue; 5692 if (binpath[0] != '\0' && 5693 strlcat(binpath, "/", PATH_MAX) >= PATH_MAX) 5694 continue; 5695 if (strlcat(binpath, argv0, PATH_MAX) >= PATH_MAX) 5696 continue; 5697 fd = open(binpath, O_RDONLY | O_CLOEXEC | O_VERIFY); 5698 if (fd != -1 || errno != ENOENT) { 5699 res = binpath; 5700 break; 5701 } 5702 } 5703 free(pathenv); 5704 } else { 5705 fd = open(argv0, O_RDONLY | O_CLOEXEC | O_VERIFY); 5706 res = argv0; 5707 } 5708 5709 if (fd == -1) { 5710 _rtld_error("Cannot open %s: %s", argv0, rtld_strerror(errno)); 5711 rtld_die(); 5712 } 5713 if (res != NULL && res[0] != '/') { 5714 res1 = xmalloc(PATH_MAX); 5715 if (realpath(res, res1) != NULL) { 5716 if (res != argv0) 5717 free(__DECONST(char *, res)); 5718 res = res1; 5719 } else { 5720 free(res1); 5721 } 5722 } 5723 *binpath_res = res; 5724 return (fd); 5725 } 5726 5727 /* 5728 * Parse a set of command-line arguments. 5729 */ 5730 static int 5731 parse_args(char* argv[], int argc, bool *use_pathp, int *fdp, 5732 const char **argv0) 5733 { 5734 const char *arg; 5735 char machine[64]; 5736 size_t sz; 5737 int arglen, fd, i, j, mib[2]; 5738 char opt; 5739 bool seen_b, seen_f; 5740 5741 dbg("Parsing command-line arguments"); 5742 *use_pathp = false; 5743 *fdp = -1; 5744 seen_b = seen_f = false; 5745 5746 for (i = 1; i < argc; i++ ) { 5747 arg = argv[i]; 5748 dbg("argv[%d]: '%s'", i, arg); 5749 5750 /* 5751 * rtld arguments end with an explicit "--" or with the first 5752 * non-prefixed argument. 5753 */ 5754 if (strcmp(arg, "--") == 0) { 5755 i++; 5756 break; 5757 } 5758 if (arg[0] != '-') 5759 break; 5760 5761 /* 5762 * All other arguments are single-character options that can 5763 * be combined, so we need to search through `arg` for them. 5764 */ 5765 arglen = strlen(arg); 5766 for (j = 1; j < arglen; j++) { 5767 opt = arg[j]; 5768 if (opt == 'h') { 5769 print_usage(argv[0]); 5770 _exit(0); 5771 } else if (opt == 'b') { 5772 if (seen_f) { 5773 _rtld_error("Both -b and -f specified"); 5774 rtld_die(); 5775 } 5776 i++; 5777 *argv0 = argv[i]; 5778 seen_b = true; 5779 break; 5780 } else if (opt == 'f') { 5781 if (seen_b) { 5782 _rtld_error("Both -b and -f specified"); 5783 rtld_die(); 5784 } 5785 5786 /* 5787 * -f XX can be used to specify a 5788 * descriptor for the binary named at 5789 * the command line (i.e., the later 5790 * argument will specify the process 5791 * name but the descriptor is what 5792 * will actually be executed). 5793 * 5794 * -f must be the last option in, e.g., -abcf. 5795 */ 5796 if (j != arglen - 1) { 5797 _rtld_error("Invalid options: %s", arg); 5798 rtld_die(); 5799 } 5800 i++; 5801 fd = parse_integer(argv[i]); 5802 if (fd == -1) { 5803 _rtld_error( 5804 "Invalid file descriptor: '%s'", 5805 argv[i]); 5806 rtld_die(); 5807 } 5808 *fdp = fd; 5809 seen_f = true; 5810 break; 5811 } else if (opt == 'p') { 5812 *use_pathp = true; 5813 } else if (opt == 'u') { 5814 trust = false; 5815 } else if (opt == 'v') { 5816 machine[0] = '\0'; 5817 mib[0] = CTL_HW; 5818 mib[1] = HW_MACHINE; 5819 sz = sizeof(machine); 5820 sysctl(mib, nitems(mib), machine, &sz, NULL, 0); 5821 rtld_printf( 5822 "FreeBSD ld-elf.so.1 %s\n" 5823 "FreeBSD_version %d\n" 5824 "Default lib path %s\n" 5825 "Env prefix %s\n" 5826 "Hint file %s\n" 5827 "libmap file %s\n", 5828 machine, 5829 __FreeBSD_version, ld_standard_library_path, 5830 ld_env_prefix, ld_elf_hints_default, 5831 ld_path_libmap_conf); 5832 _exit(0); 5833 } else { 5834 _rtld_error("Invalid argument: '%s'", arg); 5835 print_usage(argv[0]); 5836 rtld_die(); 5837 } 5838 } 5839 } 5840 5841 if (!seen_b) 5842 *argv0 = argv[i]; 5843 return (i); 5844 } 5845 5846 /* 5847 * Parse a file descriptor number without pulling in more of libc (e.g. atoi). 5848 */ 5849 static int 5850 parse_integer(const char *str) 5851 { 5852 static const int RADIX = 10; /* XXXJA: possibly support hex? */ 5853 const char *orig; 5854 int n; 5855 char c; 5856 5857 orig = str; 5858 n = 0; 5859 for (c = *str; c != '\0'; c = *++str) { 5860 if (c < '0' || c > '9') 5861 return (-1); 5862 5863 n *= RADIX; 5864 n += c - '0'; 5865 } 5866 5867 /* Make sure we actually parsed something. */ 5868 if (str == orig) 5869 return (-1); 5870 return (n); 5871 } 5872 5873 static void 5874 print_usage(const char *argv0) 5875 { 5876 5877 rtld_printf( 5878 "Usage: %s [-h] [-b <exe>] [-f <FD>] [-p] [--] <binary> [<args>]\n" 5879 "\n" 5880 "Options:\n" 5881 " -h Display this help message\n" 5882 " -b <exe> Execute <exe> instead of <binary>, arg0 is <binary>\n" 5883 " -f <FD> Execute <FD> instead of searching for <binary>\n" 5884 " -p Search in PATH for named binary\n" 5885 " -u Ignore LD_ environment variables\n" 5886 " -v Display identification information\n" 5887 " -- End of RTLD options\n" 5888 " <binary> Name of process to execute\n" 5889 " <args> Arguments to the executed process\n", argv0); 5890 } 5891 5892 /* 5893 * Overrides for libc_pic-provided functions. 5894 */ 5895 5896 int 5897 __getosreldate(void) 5898 { 5899 size_t len; 5900 int oid[2]; 5901 int error, osrel; 5902 5903 if (osreldate != 0) 5904 return (osreldate); 5905 5906 oid[0] = CTL_KERN; 5907 oid[1] = KERN_OSRELDATE; 5908 osrel = 0; 5909 len = sizeof(osrel); 5910 error = sysctl(oid, 2, &osrel, &len, NULL, 0); 5911 if (error == 0 && osrel > 0 && len == sizeof(osrel)) 5912 osreldate = osrel; 5913 return (osreldate); 5914 } 5915 const char * 5916 rtld_strerror(int errnum) 5917 { 5918 5919 if (errnum < 0 || errnum >= sys_nerr) 5920 return ("Unknown error"); 5921 return (sys_errlist[errnum]); 5922 } 5923 5924 /* malloc */ 5925 void * 5926 malloc(size_t nbytes) 5927 { 5928 5929 return (__crt_malloc(nbytes)); 5930 } 5931 5932 void * 5933 calloc(size_t num, size_t size) 5934 { 5935 5936 return (__crt_calloc(num, size)); 5937 } 5938 5939 void 5940 free(void *cp) 5941 { 5942 5943 __crt_free(cp); 5944 } 5945 5946 void * 5947 realloc(void *cp, size_t nbytes) 5948 { 5949 5950 return (__crt_realloc(cp, nbytes)); 5951 } 5952 5953 extern int _rtld_version__FreeBSD_version __exported; 5954 int _rtld_version__FreeBSD_version = __FreeBSD_version; 5955 5956 extern char _rtld_version_laddr_offset __exported; 5957 char _rtld_version_laddr_offset; 5958 5959 extern char _rtld_version_dlpi_tls_data __exported; 5960 char _rtld_version_dlpi_tls_data; 5961