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