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 = round_page(ph->p_memsz); 1561 break; 1562 1563 case PT_NOTE: 1564 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; 1565 note_end = note_start + ph->p_filesz; 1566 digest_notes(obj, note_start, note_end); 1567 break; 1568 } 1569 } 1570 if (nsegs < 1) { 1571 _rtld_error("%s: too few PT_LOAD segments", path); 1572 return NULL; 1573 } 1574 1575 obj->entry = entry; 1576 return obj; 1577 } 1578 1579 void 1580 digest_notes(Obj_Entry *obj, Elf_Addr note_start, Elf_Addr note_end) 1581 { 1582 const Elf_Note *note; 1583 const char *note_name; 1584 uintptr_t p; 1585 1586 for (note = (const Elf_Note *)note_start; (Elf_Addr)note < note_end; 1587 note = (const Elf_Note *)((const char *)(note + 1) + 1588 roundup2(note->n_namesz, sizeof(Elf32_Addr)) + 1589 roundup2(note->n_descsz, sizeof(Elf32_Addr)))) { 1590 if (note->n_namesz != sizeof(NOTE_FREEBSD_VENDOR) || 1591 note->n_descsz != sizeof(int32_t)) 1592 continue; 1593 if (note->n_type != NT_FREEBSD_ABI_TAG && 1594 note->n_type != NT_FREEBSD_FEATURE_CTL && 1595 note->n_type != NT_FREEBSD_NOINIT_TAG) 1596 continue; 1597 note_name = (const char *)(note + 1); 1598 if (strncmp(NOTE_FREEBSD_VENDOR, note_name, 1599 sizeof(NOTE_FREEBSD_VENDOR)) != 0) 1600 continue; 1601 switch (note->n_type) { 1602 case NT_FREEBSD_ABI_TAG: 1603 /* FreeBSD osrel note */ 1604 p = (uintptr_t)(note + 1); 1605 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1606 obj->osrel = *(const int32_t *)(p); 1607 dbg("note osrel %d", obj->osrel); 1608 break; 1609 case NT_FREEBSD_FEATURE_CTL: 1610 /* FreeBSD ABI feature control note */ 1611 p = (uintptr_t)(note + 1); 1612 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1613 obj->fctl0 = *(const uint32_t *)(p); 1614 dbg("note fctl0 %#x", obj->fctl0); 1615 break; 1616 case NT_FREEBSD_NOINIT_TAG: 1617 /* FreeBSD 'crt does not call init' note */ 1618 obj->crt_no_init = true; 1619 dbg("note crt_no_init"); 1620 break; 1621 } 1622 } 1623 } 1624 1625 static Obj_Entry * 1626 dlcheck(void *handle) 1627 { 1628 Obj_Entry *obj; 1629 1630 TAILQ_FOREACH(obj, &obj_list, next) { 1631 if (obj == (Obj_Entry *) handle) 1632 break; 1633 } 1634 1635 if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) { 1636 _rtld_error("Invalid shared object handle %p", handle); 1637 return NULL; 1638 } 1639 return obj; 1640 } 1641 1642 /* 1643 * If the given object is already in the donelist, return true. Otherwise 1644 * add the object to the list and return false. 1645 */ 1646 static bool 1647 donelist_check(DoneList *dlp, const Obj_Entry *obj) 1648 { 1649 unsigned int i; 1650 1651 for (i = 0; i < dlp->num_used; i++) 1652 if (dlp->objs[i] == obj) 1653 return true; 1654 /* 1655 * Our donelist allocation should always be sufficient. But if 1656 * our threads locking isn't working properly, more shared objects 1657 * could have been loaded since we allocated the list. That should 1658 * never happen, but we'll handle it properly just in case it does. 1659 */ 1660 if (dlp->num_used < dlp->num_alloc) 1661 dlp->objs[dlp->num_used++] = obj; 1662 return false; 1663 } 1664 1665 /* 1666 * Hash function for symbol table lookup. Don't even think about changing 1667 * this. It is specified by the System V ABI. 1668 */ 1669 unsigned long 1670 elf_hash(const char *name) 1671 { 1672 const unsigned char *p = (const unsigned char *) name; 1673 unsigned long h = 0; 1674 unsigned long g; 1675 1676 while (*p != '\0') { 1677 h = (h << 4) + *p++; 1678 if ((g = h & 0xf0000000) != 0) 1679 h ^= g >> 24; 1680 h &= ~g; 1681 } 1682 return h; 1683 } 1684 1685 /* 1686 * The GNU hash function is the Daniel J. Bernstein hash clipped to 32 bits 1687 * unsigned in case it's implemented with a wider type. 1688 */ 1689 static uint32_t 1690 gnu_hash(const char *s) 1691 { 1692 uint32_t h; 1693 unsigned char c; 1694 1695 h = 5381; 1696 for (c = *s; c != '\0'; c = *++s) 1697 h = h * 33 + c; 1698 return (h & 0xffffffff); 1699 } 1700 1701 1702 /* 1703 * Find the library with the given name, and return its full pathname. 1704 * The returned string is dynamically allocated. Generates an error 1705 * message and returns NULL if the library cannot be found. 1706 * 1707 * If the second argument is non-NULL, then it refers to an already- 1708 * loaded shared object, whose library search path will be searched. 1709 * 1710 * If a library is successfully located via LD_LIBRARY_PATH_FDS, its 1711 * descriptor (which is close-on-exec) will be passed out via the third 1712 * argument. 1713 * 1714 * The search order is: 1715 * DT_RPATH in the referencing file _unless_ DT_RUNPATH is present (1) 1716 * DT_RPATH of the main object if DSO without defined DT_RUNPATH (1) 1717 * LD_LIBRARY_PATH 1718 * DT_RUNPATH in the referencing file 1719 * ldconfig hints (if -z nodefaultlib, filter out default library directories 1720 * from list) 1721 * /lib:/usr/lib _unless_ the referencing file is linked with -z nodefaultlib 1722 * 1723 * (1) Handled in digest_dynamic2 - rpath left NULL if runpath defined. 1724 */ 1725 static char * 1726 find_library(const char *xname, const Obj_Entry *refobj, int *fdp) 1727 { 1728 char *pathname, *refobj_path; 1729 const char *name; 1730 bool nodeflib, objgiven; 1731 1732 objgiven = refobj != NULL; 1733 1734 if (libmap_disable || !objgiven || 1735 (name = lm_find(refobj->path, xname)) == NULL) 1736 name = xname; 1737 1738 if (strchr(name, '/') != NULL) { /* Hard coded pathname */ 1739 if (name[0] != '/' && !trust) { 1740 _rtld_error("Absolute pathname required " 1741 "for shared object \"%s\"", name); 1742 return (NULL); 1743 } 1744 return (origin_subst(__DECONST(Obj_Entry *, refobj), 1745 __DECONST(char *, name))); 1746 } 1747 1748 dbg(" Searching for \"%s\"", name); 1749 refobj_path = objgiven ? refobj->path : NULL; 1750 1751 /* 1752 * If refobj->rpath != NULL, then refobj->runpath is NULL. Fall 1753 * back to pre-conforming behaviour if user requested so with 1754 * LD_LIBRARY_PATH_RPATH environment variable and ignore -z 1755 * nodeflib. 1756 */ 1757 if (objgiven && refobj->rpath != NULL && ld_library_path_rpath) { 1758 pathname = search_library_path(name, ld_library_path, 1759 refobj_path, fdp); 1760 if (pathname != NULL) 1761 return (pathname); 1762 if (refobj != NULL) { 1763 pathname = search_library_path(name, refobj->rpath, 1764 refobj_path, fdp); 1765 if (pathname != NULL) 1766 return (pathname); 1767 } 1768 pathname = search_library_pathfds(name, ld_library_dirs, fdp); 1769 if (pathname != NULL) 1770 return (pathname); 1771 pathname = search_library_path(name, gethints(false), 1772 refobj_path, fdp); 1773 if (pathname != NULL) 1774 return (pathname); 1775 pathname = search_library_path(name, ld_standard_library_path, 1776 refobj_path, fdp); 1777 if (pathname != NULL) 1778 return (pathname); 1779 } else { 1780 nodeflib = objgiven ? refobj->z_nodeflib : false; 1781 if (objgiven) { 1782 pathname = search_library_path(name, refobj->rpath, 1783 refobj->path, fdp); 1784 if (pathname != NULL) 1785 return (pathname); 1786 } 1787 if (objgiven && refobj->runpath == NULL && refobj != obj_main) { 1788 pathname = search_library_path(name, obj_main->rpath, 1789 refobj_path, fdp); 1790 if (pathname != NULL) 1791 return (pathname); 1792 } 1793 pathname = search_library_path(name, ld_library_path, 1794 refobj_path, fdp); 1795 if (pathname != NULL) 1796 return (pathname); 1797 if (objgiven) { 1798 pathname = search_library_path(name, refobj->runpath, 1799 refobj_path, fdp); 1800 if (pathname != NULL) 1801 return (pathname); 1802 } 1803 pathname = search_library_pathfds(name, ld_library_dirs, fdp); 1804 if (pathname != NULL) 1805 return (pathname); 1806 pathname = search_library_path(name, gethints(nodeflib), 1807 refobj_path, fdp); 1808 if (pathname != NULL) 1809 return (pathname); 1810 if (objgiven && !nodeflib) { 1811 pathname = search_library_path(name, 1812 ld_standard_library_path, refobj_path, fdp); 1813 if (pathname != NULL) 1814 return (pathname); 1815 } 1816 } 1817 1818 if (objgiven && refobj->path != NULL) { 1819 _rtld_error("Shared object \"%s\" not found, " 1820 "required by \"%s\"", name, basename(refobj->path)); 1821 } else { 1822 _rtld_error("Shared object \"%s\" not found", name); 1823 } 1824 return (NULL); 1825 } 1826 1827 /* 1828 * Given a symbol number in a referencing object, find the corresponding 1829 * definition of the symbol. Returns a pointer to the symbol, or NULL if 1830 * no definition was found. Returns a pointer to the Obj_Entry of the 1831 * defining object via the reference parameter DEFOBJ_OUT. 1832 */ 1833 const Elf_Sym * 1834 find_symdef(unsigned long symnum, const Obj_Entry *refobj, 1835 const Obj_Entry **defobj_out, int flags, SymCache *cache, 1836 RtldLockState *lockstate) 1837 { 1838 const Elf_Sym *ref; 1839 const Elf_Sym *def; 1840 const Obj_Entry *defobj; 1841 const Ver_Entry *ve; 1842 SymLook req; 1843 const char *name; 1844 int res; 1845 1846 /* 1847 * If we have already found this symbol, get the information from 1848 * the cache. 1849 */ 1850 if (symnum >= refobj->dynsymcount) 1851 return NULL; /* Bad object */ 1852 if (cache != NULL && cache[symnum].sym != NULL) { 1853 *defobj_out = cache[symnum].obj; 1854 return cache[symnum].sym; 1855 } 1856 1857 ref = refobj->symtab + symnum; 1858 name = refobj->strtab + ref->st_name; 1859 def = NULL; 1860 defobj = NULL; 1861 ve = NULL; 1862 1863 /* 1864 * We don't have to do a full scale lookup if the symbol is local. 1865 * We know it will bind to the instance in this load module; to 1866 * which we already have a pointer (ie ref). By not doing a lookup, 1867 * we not only improve performance, but it also avoids unresolvable 1868 * symbols when local symbols are not in the hash table. This has 1869 * been seen with the ia64 toolchain. 1870 */ 1871 if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) { 1872 if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) { 1873 _rtld_error("%s: Bogus symbol table entry %lu", refobj->path, 1874 symnum); 1875 } 1876 symlook_init(&req, name); 1877 req.flags = flags; 1878 ve = req.ventry = fetch_ventry(refobj, symnum); 1879 req.lockstate = lockstate; 1880 res = symlook_default(&req, refobj); 1881 if (res == 0) { 1882 def = req.sym_out; 1883 defobj = req.defobj_out; 1884 } 1885 } else { 1886 def = ref; 1887 defobj = refobj; 1888 } 1889 1890 /* 1891 * If we found no definition and the reference is weak, treat the 1892 * symbol as having the value zero. 1893 */ 1894 if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) { 1895 def = &sym_zero; 1896 defobj = obj_main; 1897 } 1898 1899 if (def != NULL) { 1900 *defobj_out = defobj; 1901 /* Record the information in the cache to avoid subsequent lookups. */ 1902 if (cache != NULL) { 1903 cache[symnum].sym = def; 1904 cache[symnum].obj = defobj; 1905 } 1906 } else { 1907 if (refobj != &obj_rtld) 1908 _rtld_error("%s: Undefined symbol \"%s%s%s\"", refobj->path, name, 1909 ve != NULL ? "@" : "", ve != NULL ? ve->name : ""); 1910 } 1911 return def; 1912 } 1913 1914 /* 1915 * Return the search path from the ldconfig hints file, reading it if 1916 * necessary. If nostdlib is true, then the default search paths are 1917 * not added to result. 1918 * 1919 * Returns NULL if there are problems with the hints file, 1920 * or if the search path there is empty. 1921 */ 1922 static const char * 1923 gethints(bool nostdlib) 1924 { 1925 static char *filtered_path; 1926 static const char *hints; 1927 static struct elfhints_hdr hdr; 1928 struct fill_search_info_args sargs, hargs; 1929 struct dl_serinfo smeta, hmeta, *SLPinfo, *hintinfo; 1930 struct dl_serpath *SLPpath, *hintpath; 1931 char *p; 1932 struct stat hint_stat; 1933 unsigned int SLPndx, hintndx, fndx, fcount; 1934 int fd; 1935 size_t flen; 1936 uint32_t dl; 1937 bool skip; 1938 1939 /* First call, read the hints file */ 1940 if (hints == NULL) { 1941 /* Keep from trying again in case the hints file is bad. */ 1942 hints = ""; 1943 1944 if ((fd = open(ld_elf_hints_path, O_RDONLY | O_CLOEXEC)) == -1) 1945 return (NULL); 1946 1947 /* 1948 * Check of hdr.dirlistlen value against type limit 1949 * intends to pacify static analyzers. Further 1950 * paranoia leads to checks that dirlist is fully 1951 * contained in the file range. 1952 */ 1953 if (read(fd, &hdr, sizeof hdr) != sizeof hdr || 1954 hdr.magic != ELFHINTS_MAGIC || 1955 hdr.version != 1 || hdr.dirlistlen > UINT_MAX / 2 || 1956 fstat(fd, &hint_stat) == -1) { 1957 cleanup1: 1958 close(fd); 1959 hdr.dirlistlen = 0; 1960 return (NULL); 1961 } 1962 dl = hdr.strtab; 1963 if (dl + hdr.dirlist < dl) 1964 goto cleanup1; 1965 dl += hdr.dirlist; 1966 if (dl + hdr.dirlistlen < dl) 1967 goto cleanup1; 1968 dl += hdr.dirlistlen; 1969 if (dl > hint_stat.st_size) 1970 goto cleanup1; 1971 p = xmalloc(hdr.dirlistlen + 1); 1972 if (pread(fd, p, hdr.dirlistlen + 1, 1973 hdr.strtab + hdr.dirlist) != (ssize_t)hdr.dirlistlen + 1 || 1974 p[hdr.dirlistlen] != '\0') { 1975 free(p); 1976 goto cleanup1; 1977 } 1978 hints = p; 1979 close(fd); 1980 } 1981 1982 /* 1983 * If caller agreed to receive list which includes the default 1984 * paths, we are done. Otherwise, if we still did not 1985 * calculated filtered result, do it now. 1986 */ 1987 if (!nostdlib) 1988 return (hints[0] != '\0' ? hints : NULL); 1989 if (filtered_path != NULL) 1990 goto filt_ret; 1991 1992 /* 1993 * Obtain the list of all configured search paths, and the 1994 * list of the default paths. 1995 * 1996 * First estimate the size of the results. 1997 */ 1998 smeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 1999 smeta.dls_cnt = 0; 2000 hmeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 2001 hmeta.dls_cnt = 0; 2002 2003 sargs.request = RTLD_DI_SERINFOSIZE; 2004 sargs.serinfo = &smeta; 2005 hargs.request = RTLD_DI_SERINFOSIZE; 2006 hargs.serinfo = &hmeta; 2007 2008 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 2009 &sargs); 2010 path_enumerate(hints, fill_search_info, NULL, &hargs); 2011 2012 SLPinfo = xmalloc(smeta.dls_size); 2013 hintinfo = xmalloc(hmeta.dls_size); 2014 2015 /* 2016 * Next fetch both sets of paths. 2017 */ 2018 sargs.request = RTLD_DI_SERINFO; 2019 sargs.serinfo = SLPinfo; 2020 sargs.serpath = &SLPinfo->dls_serpath[0]; 2021 sargs.strspace = (char *)&SLPinfo->dls_serpath[smeta.dls_cnt]; 2022 2023 hargs.request = RTLD_DI_SERINFO; 2024 hargs.serinfo = hintinfo; 2025 hargs.serpath = &hintinfo->dls_serpath[0]; 2026 hargs.strspace = (char *)&hintinfo->dls_serpath[hmeta.dls_cnt]; 2027 2028 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 2029 &sargs); 2030 path_enumerate(hints, fill_search_info, NULL, &hargs); 2031 2032 /* 2033 * Now calculate the difference between two sets, by excluding 2034 * standard paths from the full set. 2035 */ 2036 fndx = 0; 2037 fcount = 0; 2038 filtered_path = xmalloc(hdr.dirlistlen + 1); 2039 hintpath = &hintinfo->dls_serpath[0]; 2040 for (hintndx = 0; hintndx < hmeta.dls_cnt; hintndx++, hintpath++) { 2041 skip = false; 2042 SLPpath = &SLPinfo->dls_serpath[0]; 2043 /* 2044 * Check each standard path against current. 2045 */ 2046 for (SLPndx = 0; SLPndx < smeta.dls_cnt; SLPndx++, SLPpath++) { 2047 /* matched, skip the path */ 2048 if (!strcmp(hintpath->dls_name, SLPpath->dls_name)) { 2049 skip = true; 2050 break; 2051 } 2052 } 2053 if (skip) 2054 continue; 2055 /* 2056 * Not matched against any standard path, add the path 2057 * to result. Separate consequtive paths with ':'. 2058 */ 2059 if (fcount > 0) { 2060 filtered_path[fndx] = ':'; 2061 fndx++; 2062 } 2063 fcount++; 2064 flen = strlen(hintpath->dls_name); 2065 strncpy((filtered_path + fndx), hintpath->dls_name, flen); 2066 fndx += flen; 2067 } 2068 filtered_path[fndx] = '\0'; 2069 2070 free(SLPinfo); 2071 free(hintinfo); 2072 2073 filt_ret: 2074 return (filtered_path[0] != '\0' ? filtered_path : NULL); 2075 } 2076 2077 static void 2078 init_dag(Obj_Entry *root) 2079 { 2080 const Needed_Entry *needed; 2081 const Objlist_Entry *elm; 2082 DoneList donelist; 2083 2084 if (root->dag_inited) 2085 return; 2086 donelist_init(&donelist); 2087 2088 /* Root object belongs to own DAG. */ 2089 objlist_push_tail(&root->dldags, root); 2090 objlist_push_tail(&root->dagmembers, root); 2091 donelist_check(&donelist, root); 2092 2093 /* 2094 * Add dependencies of root object to DAG in breadth order 2095 * by exploiting the fact that each new object get added 2096 * to the tail of the dagmembers list. 2097 */ 2098 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2099 for (needed = elm->obj->needed; needed != NULL; needed = needed->next) { 2100 if (needed->obj == NULL || donelist_check(&donelist, needed->obj)) 2101 continue; 2102 objlist_push_tail(&needed->obj->dldags, root); 2103 objlist_push_tail(&root->dagmembers, needed->obj); 2104 } 2105 } 2106 root->dag_inited = true; 2107 } 2108 2109 static void 2110 init_marker(Obj_Entry *marker) 2111 { 2112 2113 bzero(marker, sizeof(*marker)); 2114 marker->marker = true; 2115 } 2116 2117 Obj_Entry * 2118 globallist_curr(const Obj_Entry *obj) 2119 { 2120 2121 for (;;) { 2122 if (obj == NULL) 2123 return (NULL); 2124 if (!obj->marker) 2125 return (__DECONST(Obj_Entry *, obj)); 2126 obj = TAILQ_PREV(obj, obj_entry_q, next); 2127 } 2128 } 2129 2130 Obj_Entry * 2131 globallist_next(const Obj_Entry *obj) 2132 { 2133 2134 for (;;) { 2135 obj = TAILQ_NEXT(obj, next); 2136 if (obj == NULL) 2137 return (NULL); 2138 if (!obj->marker) 2139 return (__DECONST(Obj_Entry *, obj)); 2140 } 2141 } 2142 2143 /* Prevent the object from being unmapped while the bind lock is dropped. */ 2144 static void 2145 hold_object(Obj_Entry *obj) 2146 { 2147 2148 obj->holdcount++; 2149 } 2150 2151 static void 2152 unhold_object(Obj_Entry *obj) 2153 { 2154 2155 assert(obj->holdcount > 0); 2156 if (--obj->holdcount == 0 && obj->unholdfree) 2157 release_object(obj); 2158 } 2159 2160 static void 2161 process_z(Obj_Entry *root) 2162 { 2163 const Objlist_Entry *elm; 2164 Obj_Entry *obj; 2165 2166 /* 2167 * Walk over object DAG and process every dependent object 2168 * that is marked as DF_1_NODELETE or DF_1_GLOBAL. They need 2169 * to grow their own DAG. 2170 * 2171 * For DF_1_GLOBAL, DAG is required for symbol lookups in 2172 * symlook_global() to work. 2173 * 2174 * For DF_1_NODELETE, the DAG should have its reference upped. 2175 */ 2176 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2177 obj = elm->obj; 2178 if (obj == NULL) 2179 continue; 2180 if (obj->z_nodelete && !obj->ref_nodel) { 2181 dbg("obj %s -z nodelete", obj->path); 2182 init_dag(obj); 2183 ref_dag(obj); 2184 obj->ref_nodel = true; 2185 } 2186 if (obj->z_global && objlist_find(&list_global, obj) == NULL) { 2187 dbg("obj %s -z global", obj->path); 2188 objlist_push_tail(&list_global, obj); 2189 init_dag(obj); 2190 } 2191 } 2192 } 2193 2194 static void 2195 parse_rtld_phdr(Obj_Entry *obj) 2196 { 2197 const Elf_Phdr *ph; 2198 Elf_Addr note_start, note_end; 2199 2200 obj->stack_flags = PF_X | PF_R | PF_W; 2201 for (ph = obj->phdr; (const char *)ph < (const char *)obj->phdr + 2202 obj->phsize; ph++) { 2203 switch (ph->p_type) { 2204 case PT_GNU_STACK: 2205 obj->stack_flags = ph->p_flags; 2206 break; 2207 case PT_GNU_RELRO: 2208 obj->relro_page = obj->relocbase + 2209 trunc_page(ph->p_vaddr); 2210 obj->relro_size = round_page(ph->p_memsz); 2211 break; 2212 case PT_NOTE: 2213 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; 2214 note_end = note_start + ph->p_filesz; 2215 digest_notes(obj, note_start, note_end); 2216 break; 2217 } 2218 } 2219 } 2220 2221 /* 2222 * Initialize the dynamic linker. The argument is the address at which 2223 * the dynamic linker has been mapped into memory. The primary task of 2224 * this function is to relocate the dynamic linker. 2225 */ 2226 static void 2227 init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info) 2228 { 2229 Obj_Entry objtmp; /* Temporary rtld object */ 2230 const Elf_Ehdr *ehdr; 2231 const Elf_Dyn *dyn_rpath; 2232 const Elf_Dyn *dyn_soname; 2233 const Elf_Dyn *dyn_runpath; 2234 2235 #ifdef RTLD_INIT_PAGESIZES_EARLY 2236 /* The page size is required by the dynamic memory allocator. */ 2237 init_pagesizes(aux_info); 2238 #endif 2239 2240 /* 2241 * Conjure up an Obj_Entry structure for the dynamic linker. 2242 * 2243 * The "path" member can't be initialized yet because string constants 2244 * cannot yet be accessed. Below we will set it correctly. 2245 */ 2246 memset(&objtmp, 0, sizeof(objtmp)); 2247 objtmp.path = NULL; 2248 objtmp.rtld = true; 2249 objtmp.mapbase = mapbase; 2250 #ifdef PIC 2251 objtmp.relocbase = mapbase; 2252 #endif 2253 2254 objtmp.dynamic = rtld_dynamic(&objtmp); 2255 digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname, &dyn_runpath); 2256 assert(objtmp.needed == NULL); 2257 #if !defined(__mips__) 2258 /* MIPS has a bogus DT_TEXTREL. */ 2259 assert(!objtmp.textrel); 2260 #endif 2261 /* 2262 * Temporarily put the dynamic linker entry into the object list, so 2263 * that symbols can be found. 2264 */ 2265 relocate_objects(&objtmp, true, &objtmp, 0, NULL); 2266 2267 ehdr = (Elf_Ehdr *)mapbase; 2268 objtmp.phdr = (Elf_Phdr *)((char *)mapbase + ehdr->e_phoff); 2269 objtmp.phsize = ehdr->e_phnum * sizeof(objtmp.phdr[0]); 2270 2271 /* Initialize the object list. */ 2272 TAILQ_INIT(&obj_list); 2273 2274 /* Now that non-local variables can be accesses, copy out obj_rtld. */ 2275 memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld)); 2276 2277 #ifndef RTLD_INIT_PAGESIZES_EARLY 2278 /* The page size is required by the dynamic memory allocator. */ 2279 init_pagesizes(aux_info); 2280 #endif 2281 2282 if (aux_info[AT_OSRELDATE] != NULL) 2283 osreldate = aux_info[AT_OSRELDATE]->a_un.a_val; 2284 2285 digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname, dyn_runpath); 2286 2287 /* Replace the path with a dynamically allocated copy. */ 2288 obj_rtld.path = xstrdup(ld_path_rtld); 2289 2290 parse_rtld_phdr(&obj_rtld); 2291 if (obj_enforce_relro(&obj_rtld) == -1) 2292 rtld_die(); 2293 2294 r_debug.r_version = R_DEBUG_VERSION; 2295 r_debug.r_brk = r_debug_state; 2296 r_debug.r_state = RT_CONSISTENT; 2297 r_debug.r_ldbase = obj_rtld.relocbase; 2298 } 2299 2300 /* 2301 * Retrieve the array of supported page sizes. The kernel provides the page 2302 * sizes in increasing order. 2303 */ 2304 static void 2305 init_pagesizes(Elf_Auxinfo **aux_info) 2306 { 2307 static size_t psa[MAXPAGESIZES]; 2308 int mib[2]; 2309 size_t len, size; 2310 2311 if (aux_info[AT_PAGESIZES] != NULL && aux_info[AT_PAGESIZESLEN] != 2312 NULL) { 2313 size = aux_info[AT_PAGESIZESLEN]->a_un.a_val; 2314 pagesizes = aux_info[AT_PAGESIZES]->a_un.a_ptr; 2315 } else { 2316 len = 2; 2317 if (sysctlnametomib("hw.pagesizes", mib, &len) == 0) 2318 size = sizeof(psa); 2319 else { 2320 /* As a fallback, retrieve the base page size. */ 2321 size = sizeof(psa[0]); 2322 if (aux_info[AT_PAGESZ] != NULL) { 2323 psa[0] = aux_info[AT_PAGESZ]->a_un.a_val; 2324 goto psa_filled; 2325 } else { 2326 mib[0] = CTL_HW; 2327 mib[1] = HW_PAGESIZE; 2328 len = 2; 2329 } 2330 } 2331 if (sysctl(mib, len, psa, &size, NULL, 0) == -1) { 2332 _rtld_error("sysctl for hw.pagesize(s) failed"); 2333 rtld_die(); 2334 } 2335 psa_filled: 2336 pagesizes = psa; 2337 } 2338 npagesizes = size / sizeof(pagesizes[0]); 2339 /* Discard any invalid entries at the end of the array. */ 2340 while (npagesizes > 0 && pagesizes[npagesizes - 1] == 0) 2341 npagesizes--; 2342 } 2343 2344 /* 2345 * Add the init functions from a needed object list (and its recursive 2346 * needed objects) to "list". This is not used directly; it is a helper 2347 * function for initlist_add_objects(). The write lock must be held 2348 * when this function is called. 2349 */ 2350 static void 2351 initlist_add_neededs(Needed_Entry *needed, Objlist *list) 2352 { 2353 /* Recursively process the successor needed objects. */ 2354 if (needed->next != NULL) 2355 initlist_add_neededs(needed->next, list); 2356 2357 /* Process the current needed object. */ 2358 if (needed->obj != NULL) 2359 initlist_add_objects(needed->obj, needed->obj, list); 2360 } 2361 2362 /* 2363 * Scan all of the DAGs rooted in the range of objects from "obj" to 2364 * "tail" and add their init functions to "list". This recurses over 2365 * the DAGs and ensure the proper init ordering such that each object's 2366 * needed libraries are initialized before the object itself. At the 2367 * same time, this function adds the objects to the global finalization 2368 * list "list_fini" in the opposite order. The write lock must be 2369 * held when this function is called. 2370 */ 2371 static void 2372 initlist_add_objects(Obj_Entry *obj, Obj_Entry *tail, Objlist *list) 2373 { 2374 Obj_Entry *nobj; 2375 2376 if (obj->init_scanned || obj->init_done) 2377 return; 2378 obj->init_scanned = true; 2379 2380 /* Recursively process the successor objects. */ 2381 nobj = globallist_next(obj); 2382 if (nobj != NULL && obj != tail) 2383 initlist_add_objects(nobj, tail, list); 2384 2385 /* Recursively process the needed objects. */ 2386 if (obj->needed != NULL) 2387 initlist_add_neededs(obj->needed, list); 2388 if (obj->needed_filtees != NULL) 2389 initlist_add_neededs(obj->needed_filtees, list); 2390 if (obj->needed_aux_filtees != NULL) 2391 initlist_add_neededs(obj->needed_aux_filtees, list); 2392 2393 /* Add the object to the init list. */ 2394 objlist_push_tail(list, obj); 2395 2396 /* Add the object to the global fini list in the reverse order. */ 2397 if ((obj->fini != (Elf_Addr)NULL || obj->fini_array != (Elf_Addr)NULL) 2398 && !obj->on_fini_list) { 2399 objlist_push_head(&list_fini, obj); 2400 obj->on_fini_list = true; 2401 } 2402 } 2403 2404 #ifndef FPTR_TARGET 2405 #define FPTR_TARGET(f) ((Elf_Addr) (f)) 2406 #endif 2407 2408 static void 2409 free_needed_filtees(Needed_Entry *n, RtldLockState *lockstate) 2410 { 2411 Needed_Entry *needed, *needed1; 2412 2413 for (needed = n; needed != NULL; needed = needed->next) { 2414 if (needed->obj != NULL) { 2415 dlclose_locked(needed->obj, lockstate); 2416 needed->obj = NULL; 2417 } 2418 } 2419 for (needed = n; needed != NULL; needed = needed1) { 2420 needed1 = needed->next; 2421 free(needed); 2422 } 2423 } 2424 2425 static void 2426 unload_filtees(Obj_Entry *obj, RtldLockState *lockstate) 2427 { 2428 2429 free_needed_filtees(obj->needed_filtees, lockstate); 2430 obj->needed_filtees = NULL; 2431 free_needed_filtees(obj->needed_aux_filtees, lockstate); 2432 obj->needed_aux_filtees = NULL; 2433 obj->filtees_loaded = false; 2434 } 2435 2436 static void 2437 load_filtee1(Obj_Entry *obj, Needed_Entry *needed, int flags, 2438 RtldLockState *lockstate) 2439 { 2440 2441 for (; needed != NULL; needed = needed->next) { 2442 needed->obj = dlopen_object(obj->strtab + needed->name, -1, obj, 2443 flags, ((ld_loadfltr || obj->z_loadfltr) ? RTLD_NOW : RTLD_LAZY) | 2444 RTLD_LOCAL, lockstate); 2445 } 2446 } 2447 2448 static void 2449 load_filtees(Obj_Entry *obj, int flags, RtldLockState *lockstate) 2450 { 2451 2452 lock_restart_for_upgrade(lockstate); 2453 if (!obj->filtees_loaded) { 2454 load_filtee1(obj, obj->needed_filtees, flags, lockstate); 2455 load_filtee1(obj, obj->needed_aux_filtees, flags, lockstate); 2456 obj->filtees_loaded = true; 2457 } 2458 } 2459 2460 static int 2461 process_needed(Obj_Entry *obj, Needed_Entry *needed, int flags) 2462 { 2463 Obj_Entry *obj1; 2464 2465 for (; needed != NULL; needed = needed->next) { 2466 obj1 = needed->obj = load_object(obj->strtab + needed->name, -1, obj, 2467 flags & ~RTLD_LO_NOLOAD); 2468 if (obj1 == NULL && !ld_tracing && (flags & RTLD_LO_FILTEES) == 0) 2469 return (-1); 2470 } 2471 return (0); 2472 } 2473 2474 /* 2475 * Given a shared object, traverse its list of needed objects, and load 2476 * each of them. Returns 0 on success. Generates an error message and 2477 * returns -1 on failure. 2478 */ 2479 static int 2480 load_needed_objects(Obj_Entry *first, int flags) 2481 { 2482 Obj_Entry *obj; 2483 2484 for (obj = first; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 2485 if (obj->marker) 2486 continue; 2487 if (process_needed(obj, obj->needed, flags) == -1) 2488 return (-1); 2489 } 2490 return (0); 2491 } 2492 2493 static int 2494 load_preload_objects(char *p, bool isfd) 2495 { 2496 Obj_Entry *obj; 2497 static const char delim[] = " \t:;"; 2498 2499 if (p == NULL) 2500 return (0); 2501 2502 p += strspn(p, delim); 2503 while (*p != '\0') { 2504 const char *name; 2505 size_t len = strcspn(p, delim); 2506 char savech; 2507 int fd; 2508 2509 savech = p[len]; 2510 p[len] = '\0'; 2511 if (isfd) { 2512 name = NULL; 2513 fd = parse_integer(p); 2514 if (fd == -1) 2515 return (-1); 2516 } else { 2517 name = p; 2518 fd = -1; 2519 } 2520 2521 obj = load_object(name, fd, NULL, 0); 2522 if (obj == NULL) 2523 return (-1); /* XXX - cleanup */ 2524 obj->z_interpose = true; 2525 p[len] = savech; 2526 p += len; 2527 p += strspn(p, delim); 2528 } 2529 LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL); 2530 2531 return (0); 2532 } 2533 2534 static const char * 2535 printable_path(const char *path) 2536 { 2537 2538 return (path == NULL ? "<unknown>" : path); 2539 } 2540 2541 /* 2542 * Load a shared object into memory, if it is not already loaded. The 2543 * object may be specified by name or by user-supplied file descriptor 2544 * fd_u. In the later case, the fd_u descriptor is not closed, but its 2545 * duplicate is. 2546 * 2547 * Returns a pointer to the Obj_Entry for the object. Returns NULL 2548 * on failure. 2549 */ 2550 static Obj_Entry * 2551 load_object(const char *name, int fd_u, const Obj_Entry *refobj, int flags) 2552 { 2553 Obj_Entry *obj; 2554 int fd; 2555 struct stat sb; 2556 char *path; 2557 2558 fd = -1; 2559 if (name != NULL) { 2560 TAILQ_FOREACH(obj, &obj_list, next) { 2561 if (obj->marker || obj->doomed) 2562 continue; 2563 if (object_match_name(obj, name)) 2564 return (obj); 2565 } 2566 2567 path = find_library(name, refobj, &fd); 2568 if (path == NULL) 2569 return (NULL); 2570 } else 2571 path = NULL; 2572 2573 if (fd >= 0) { 2574 /* 2575 * search_library_pathfds() opens a fresh file descriptor for the 2576 * library, so there is no need to dup(). 2577 */ 2578 } else if (fd_u == -1) { 2579 /* 2580 * If we didn't find a match by pathname, or the name is not 2581 * supplied, open the file and check again by device and inode. 2582 * This avoids false mismatches caused by multiple links or ".." 2583 * in pathnames. 2584 * 2585 * To avoid a race, we open the file and use fstat() rather than 2586 * using stat(). 2587 */ 2588 if ((fd = open(path, O_RDONLY | O_CLOEXEC | O_VERIFY)) == -1) { 2589 _rtld_error("Cannot open \"%s\"", path); 2590 free(path); 2591 return (NULL); 2592 } 2593 } else { 2594 fd = fcntl(fd_u, F_DUPFD_CLOEXEC, 0); 2595 if (fd == -1) { 2596 _rtld_error("Cannot dup fd"); 2597 free(path); 2598 return (NULL); 2599 } 2600 } 2601 if (fstat(fd, &sb) == -1) { 2602 _rtld_error("Cannot fstat \"%s\"", printable_path(path)); 2603 close(fd); 2604 free(path); 2605 return NULL; 2606 } 2607 TAILQ_FOREACH(obj, &obj_list, next) { 2608 if (obj->marker || obj->doomed) 2609 continue; 2610 if (obj->ino == sb.st_ino && obj->dev == sb.st_dev) 2611 break; 2612 } 2613 if (obj != NULL && name != NULL) { 2614 object_add_name(obj, name); 2615 free(path); 2616 close(fd); 2617 return obj; 2618 } 2619 if (flags & RTLD_LO_NOLOAD) { 2620 free(path); 2621 close(fd); 2622 return (NULL); 2623 } 2624 2625 /* First use of this object, so we must map it in */ 2626 obj = do_load_object(fd, name, path, &sb, flags); 2627 if (obj == NULL) 2628 free(path); 2629 close(fd); 2630 2631 return obj; 2632 } 2633 2634 static Obj_Entry * 2635 do_load_object(int fd, const char *name, char *path, struct stat *sbp, 2636 int flags) 2637 { 2638 Obj_Entry *obj; 2639 struct statfs fs; 2640 2641 /* 2642 * but first, make sure that environment variables haven't been 2643 * used to circumvent the noexec flag on a filesystem. 2644 */ 2645 if (dangerous_ld_env) { 2646 if (fstatfs(fd, &fs) != 0) { 2647 _rtld_error("Cannot fstatfs \"%s\"", printable_path(path)); 2648 return NULL; 2649 } 2650 if (fs.f_flags & MNT_NOEXEC) { 2651 _rtld_error("Cannot execute objects on %s", fs.f_mntonname); 2652 return NULL; 2653 } 2654 } 2655 dbg("loading \"%s\"", printable_path(path)); 2656 obj = map_object(fd, printable_path(path), sbp); 2657 if (obj == NULL) 2658 return NULL; 2659 2660 /* 2661 * If DT_SONAME is present in the object, digest_dynamic2 already 2662 * added it to the object names. 2663 */ 2664 if (name != NULL) 2665 object_add_name(obj, name); 2666 obj->path = path; 2667 if (!digest_dynamic(obj, 0)) 2668 goto errp; 2669 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", obj->path, 2670 obj->valid_hash_sysv, obj->valid_hash_gnu, obj->dynsymcount); 2671 if (obj->z_pie && (flags & RTLD_LO_TRACE) == 0) { 2672 dbg("refusing to load PIE executable \"%s\"", obj->path); 2673 _rtld_error("Cannot load PIE binary %s as DSO", obj->path); 2674 goto errp; 2675 } 2676 if (obj->z_noopen && (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) == 2677 RTLD_LO_DLOPEN) { 2678 dbg("refusing to load non-loadable \"%s\"", obj->path); 2679 _rtld_error("Cannot dlopen non-loadable %s", obj->path); 2680 goto errp; 2681 } 2682 2683 obj->dlopened = (flags & RTLD_LO_DLOPEN) != 0; 2684 TAILQ_INSERT_TAIL(&obj_list, obj, next); 2685 obj_count++; 2686 obj_loads++; 2687 linkmap_add(obj); /* for GDB & dlinfo() */ 2688 max_stack_flags |= obj->stack_flags; 2689 2690 dbg(" %p .. %p: %s", obj->mapbase, 2691 obj->mapbase + obj->mapsize - 1, obj->path); 2692 if (obj->textrel) 2693 dbg(" WARNING: %s has impure text", obj->path); 2694 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 2695 obj->path); 2696 2697 return (obj); 2698 2699 errp: 2700 munmap(obj->mapbase, obj->mapsize); 2701 obj_free(obj); 2702 return (NULL); 2703 } 2704 2705 Obj_Entry * 2706 obj_from_addr(const void *addr) 2707 { 2708 Obj_Entry *obj; 2709 2710 TAILQ_FOREACH(obj, &obj_list, next) { 2711 if (obj->marker) 2712 continue; 2713 if (addr < (void *) obj->mapbase) 2714 continue; 2715 if (addr < (void *)(obj->mapbase + obj->mapsize)) 2716 return obj; 2717 } 2718 return NULL; 2719 } 2720 2721 static void 2722 preinit_main(void) 2723 { 2724 Elf_Addr *preinit_addr; 2725 int index; 2726 2727 preinit_addr = (Elf_Addr *)obj_main->preinit_array; 2728 if (preinit_addr == NULL) 2729 return; 2730 2731 for (index = 0; index < obj_main->preinit_array_num; index++) { 2732 if (preinit_addr[index] != 0 && preinit_addr[index] != 1) { 2733 dbg("calling preinit function for %s at %p", obj_main->path, 2734 (void *)preinit_addr[index]); 2735 LD_UTRACE(UTRACE_INIT_CALL, obj_main, (void *)preinit_addr[index], 2736 0, 0, obj_main->path); 2737 call_init_pointer(obj_main, preinit_addr[index]); 2738 } 2739 } 2740 } 2741 2742 /* 2743 * Call the finalization functions for each of the objects in "list" 2744 * belonging to the DAG of "root" and referenced once. If NULL "root" 2745 * is specified, every finalization function will be called regardless 2746 * of the reference count and the list elements won't be freed. All of 2747 * the objects are expected to have non-NULL fini functions. 2748 */ 2749 static void 2750 objlist_call_fini(Objlist *list, Obj_Entry *root, RtldLockState *lockstate) 2751 { 2752 Objlist_Entry *elm; 2753 struct dlerror_save *saved_msg; 2754 Elf_Addr *fini_addr; 2755 int index; 2756 2757 assert(root == NULL || root->refcount == 1); 2758 2759 if (root != NULL) 2760 root->doomed = true; 2761 2762 /* 2763 * Preserve the current error message since a fini function might 2764 * call into the dynamic linker and overwrite it. 2765 */ 2766 saved_msg = errmsg_save(); 2767 do { 2768 STAILQ_FOREACH(elm, list, link) { 2769 if (root != NULL && (elm->obj->refcount != 1 || 2770 objlist_find(&root->dagmembers, elm->obj) == NULL)) 2771 continue; 2772 /* Remove object from fini list to prevent recursive invocation. */ 2773 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 2774 /* Ensure that new references cannot be acquired. */ 2775 elm->obj->doomed = true; 2776 2777 hold_object(elm->obj); 2778 lock_release(rtld_bind_lock, lockstate); 2779 /* 2780 * It is legal to have both DT_FINI and DT_FINI_ARRAY defined. 2781 * When this happens, DT_FINI_ARRAY is processed first. 2782 */ 2783 fini_addr = (Elf_Addr *)elm->obj->fini_array; 2784 if (fini_addr != NULL && elm->obj->fini_array_num > 0) { 2785 for (index = elm->obj->fini_array_num - 1; index >= 0; 2786 index--) { 2787 if (fini_addr[index] != 0 && fini_addr[index] != 1) { 2788 dbg("calling fini function for %s at %p", 2789 elm->obj->path, (void *)fini_addr[index]); 2790 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, 2791 (void *)fini_addr[index], 0, 0, elm->obj->path); 2792 call_initfini_pointer(elm->obj, fini_addr[index]); 2793 } 2794 } 2795 } 2796 if (elm->obj->fini != (Elf_Addr)NULL) { 2797 dbg("calling fini function for %s at %p", elm->obj->path, 2798 (void *)elm->obj->fini); 2799 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, (void *)elm->obj->fini, 2800 0, 0, elm->obj->path); 2801 call_initfini_pointer(elm->obj, elm->obj->fini); 2802 } 2803 wlock_acquire(rtld_bind_lock, lockstate); 2804 unhold_object(elm->obj); 2805 /* No need to free anything if process is going down. */ 2806 if (root != NULL) 2807 free(elm); 2808 /* 2809 * We must restart the list traversal after every fini call 2810 * because a dlclose() call from the fini function or from 2811 * another thread might have modified the reference counts. 2812 */ 2813 break; 2814 } 2815 } while (elm != NULL); 2816 errmsg_restore(saved_msg); 2817 } 2818 2819 /* 2820 * Call the initialization functions for each of the objects in 2821 * "list". All of the objects are expected to have non-NULL init 2822 * functions. 2823 */ 2824 static void 2825 objlist_call_init(Objlist *list, RtldLockState *lockstate) 2826 { 2827 Objlist_Entry *elm; 2828 Obj_Entry *obj; 2829 struct dlerror_save *saved_msg; 2830 Elf_Addr *init_addr; 2831 void (*reg)(void (*)(void)); 2832 int index; 2833 2834 /* 2835 * Clean init_scanned flag so that objects can be rechecked and 2836 * possibly initialized earlier if any of vectors called below 2837 * cause the change by using dlopen. 2838 */ 2839 TAILQ_FOREACH(obj, &obj_list, next) { 2840 if (obj->marker) 2841 continue; 2842 obj->init_scanned = false; 2843 } 2844 2845 /* 2846 * Preserve the current error message since an init function might 2847 * call into the dynamic linker and overwrite it. 2848 */ 2849 saved_msg = errmsg_save(); 2850 STAILQ_FOREACH(elm, list, link) { 2851 if (elm->obj->init_done) /* Initialized early. */ 2852 continue; 2853 /* 2854 * Race: other thread might try to use this object before current 2855 * one completes the initialization. Not much can be done here 2856 * without better locking. 2857 */ 2858 elm->obj->init_done = true; 2859 hold_object(elm->obj); 2860 reg = NULL; 2861 if (elm->obj == obj_main && obj_main->crt_no_init) { 2862 reg = (void (*)(void (*)(void)))get_program_var_addr( 2863 "__libc_atexit", lockstate); 2864 } 2865 lock_release(rtld_bind_lock, lockstate); 2866 if (reg != NULL) { 2867 reg(rtld_exit); 2868 rtld_exit_ptr = rtld_nop_exit; 2869 } 2870 2871 /* 2872 * It is legal to have both DT_INIT and DT_INIT_ARRAY defined. 2873 * When this happens, DT_INIT is processed first. 2874 */ 2875 if (elm->obj->init != (Elf_Addr)NULL) { 2876 dbg("calling init function for %s at %p", elm->obj->path, 2877 (void *)elm->obj->init); 2878 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, (void *)elm->obj->init, 2879 0, 0, elm->obj->path); 2880 call_init_pointer(elm->obj, elm->obj->init); 2881 } 2882 init_addr = (Elf_Addr *)elm->obj->init_array; 2883 if (init_addr != NULL) { 2884 for (index = 0; index < elm->obj->init_array_num; index++) { 2885 if (init_addr[index] != 0 && init_addr[index] != 1) { 2886 dbg("calling init function for %s at %p", elm->obj->path, 2887 (void *)init_addr[index]); 2888 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, 2889 (void *)init_addr[index], 0, 0, elm->obj->path); 2890 call_init_pointer(elm->obj, init_addr[index]); 2891 } 2892 } 2893 } 2894 wlock_acquire(rtld_bind_lock, lockstate); 2895 unhold_object(elm->obj); 2896 } 2897 errmsg_restore(saved_msg); 2898 } 2899 2900 static void 2901 objlist_clear(Objlist *list) 2902 { 2903 Objlist_Entry *elm; 2904 2905 while (!STAILQ_EMPTY(list)) { 2906 elm = STAILQ_FIRST(list); 2907 STAILQ_REMOVE_HEAD(list, link); 2908 free(elm); 2909 } 2910 } 2911 2912 static Objlist_Entry * 2913 objlist_find(Objlist *list, const Obj_Entry *obj) 2914 { 2915 Objlist_Entry *elm; 2916 2917 STAILQ_FOREACH(elm, list, link) 2918 if (elm->obj == obj) 2919 return elm; 2920 return NULL; 2921 } 2922 2923 static void 2924 objlist_init(Objlist *list) 2925 { 2926 STAILQ_INIT(list); 2927 } 2928 2929 static void 2930 objlist_push_head(Objlist *list, Obj_Entry *obj) 2931 { 2932 Objlist_Entry *elm; 2933 2934 elm = NEW(Objlist_Entry); 2935 elm->obj = obj; 2936 STAILQ_INSERT_HEAD(list, elm, link); 2937 } 2938 2939 static void 2940 objlist_push_tail(Objlist *list, Obj_Entry *obj) 2941 { 2942 Objlist_Entry *elm; 2943 2944 elm = NEW(Objlist_Entry); 2945 elm->obj = obj; 2946 STAILQ_INSERT_TAIL(list, elm, link); 2947 } 2948 2949 static void 2950 objlist_put_after(Objlist *list, Obj_Entry *listobj, Obj_Entry *obj) 2951 { 2952 Objlist_Entry *elm, *listelm; 2953 2954 STAILQ_FOREACH(listelm, list, link) { 2955 if (listelm->obj == listobj) 2956 break; 2957 } 2958 elm = NEW(Objlist_Entry); 2959 elm->obj = obj; 2960 if (listelm != NULL) 2961 STAILQ_INSERT_AFTER(list, listelm, elm, link); 2962 else 2963 STAILQ_INSERT_TAIL(list, elm, link); 2964 } 2965 2966 static void 2967 objlist_remove(Objlist *list, Obj_Entry *obj) 2968 { 2969 Objlist_Entry *elm; 2970 2971 if ((elm = objlist_find(list, obj)) != NULL) { 2972 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 2973 free(elm); 2974 } 2975 } 2976 2977 /* 2978 * Relocate dag rooted in the specified object. 2979 * Returns 0 on success, or -1 on failure. 2980 */ 2981 2982 static int 2983 relocate_object_dag(Obj_Entry *root, bool bind_now, Obj_Entry *rtldobj, 2984 int flags, RtldLockState *lockstate) 2985 { 2986 Objlist_Entry *elm; 2987 int error; 2988 2989 error = 0; 2990 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2991 error = relocate_object(elm->obj, bind_now, rtldobj, flags, 2992 lockstate); 2993 if (error == -1) 2994 break; 2995 } 2996 return (error); 2997 } 2998 2999 /* 3000 * Prepare for, or clean after, relocating an object marked with 3001 * DT_TEXTREL or DF_TEXTREL. Before relocating, all read-only 3002 * segments are remapped read-write. After relocations are done, the 3003 * segment's permissions are returned back to the modes specified in 3004 * the phdrs. If any relocation happened, or always for wired 3005 * program, COW is triggered. 3006 */ 3007 static int 3008 reloc_textrel_prot(Obj_Entry *obj, bool before) 3009 { 3010 const Elf_Phdr *ph; 3011 void *base; 3012 size_t l, sz; 3013 int prot; 3014 3015 for (l = obj->phsize / sizeof(*ph), ph = obj->phdr; l > 0; 3016 l--, ph++) { 3017 if (ph->p_type != PT_LOAD || (ph->p_flags & PF_W) != 0) 3018 continue; 3019 base = obj->relocbase + trunc_page(ph->p_vaddr); 3020 sz = round_page(ph->p_vaddr + ph->p_filesz) - 3021 trunc_page(ph->p_vaddr); 3022 prot = before ? (PROT_READ | PROT_WRITE) : 3023 convert_prot(ph->p_flags); 3024 if (mprotect(base, sz, prot) == -1) { 3025 _rtld_error("%s: Cannot write-%sable text segment: %s", 3026 obj->path, before ? "en" : "dis", 3027 rtld_strerror(errno)); 3028 return (-1); 3029 } 3030 } 3031 return (0); 3032 } 3033 3034 /* 3035 * Relocate single object. 3036 * Returns 0 on success, or -1 on failure. 3037 */ 3038 static int 3039 relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, 3040 int flags, RtldLockState *lockstate) 3041 { 3042 3043 if (obj->relocated) 3044 return (0); 3045 obj->relocated = true; 3046 if (obj != rtldobj) 3047 dbg("relocating \"%s\"", obj->path); 3048 3049 if (obj->symtab == NULL || obj->strtab == NULL || 3050 !(obj->valid_hash_sysv || obj->valid_hash_gnu)) 3051 dbg("object %s has no run-time symbol table", obj->path); 3052 3053 /* There are relocations to the write-protected text segment. */ 3054 if (obj->textrel && reloc_textrel_prot(obj, true) != 0) 3055 return (-1); 3056 3057 /* Process the non-PLT non-IFUNC relocations. */ 3058 if (reloc_non_plt(obj, rtldobj, flags, lockstate)) 3059 return (-1); 3060 3061 /* Re-protected the text segment. */ 3062 if (obj->textrel && reloc_textrel_prot(obj, false) != 0) 3063 return (-1); 3064 3065 /* Set the special PLT or GOT entries. */ 3066 init_pltgot(obj); 3067 3068 /* Process the PLT relocations. */ 3069 if (reloc_plt(obj, flags, lockstate) == -1) 3070 return (-1); 3071 /* Relocate the jump slots if we are doing immediate binding. */ 3072 if ((obj->bind_now || bind_now) && reloc_jmpslots(obj, flags, 3073 lockstate) == -1) 3074 return (-1); 3075 3076 if (!obj->mainprog && obj_enforce_relro(obj) == -1) 3077 return (-1); 3078 3079 /* 3080 * Set up the magic number and version in the Obj_Entry. These 3081 * were checked in the crt1.o from the original ElfKit, so we 3082 * set them for backward compatibility. 3083 */ 3084 obj->magic = RTLD_MAGIC; 3085 obj->version = RTLD_VERSION; 3086 3087 return (0); 3088 } 3089 3090 /* 3091 * Relocate newly-loaded shared objects. The argument is a pointer to 3092 * the Obj_Entry for the first such object. All objects from the first 3093 * to the end of the list of objects are relocated. Returns 0 on success, 3094 * or -1 on failure. 3095 */ 3096 static int 3097 relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj, 3098 int flags, RtldLockState *lockstate) 3099 { 3100 Obj_Entry *obj; 3101 int error; 3102 3103 for (error = 0, obj = first; obj != NULL; 3104 obj = TAILQ_NEXT(obj, next)) { 3105 if (obj->marker) 3106 continue; 3107 error = relocate_object(obj, bind_now, rtldobj, flags, 3108 lockstate); 3109 if (error == -1) 3110 break; 3111 } 3112 return (error); 3113 } 3114 3115 /* 3116 * The handling of R_MACHINE_IRELATIVE relocations and jumpslots 3117 * referencing STT_GNU_IFUNC symbols is postponed till the other 3118 * relocations are done. The indirect functions specified as 3119 * ifunc are allowed to call other symbols, so we need to have 3120 * objects relocated before asking for resolution from indirects. 3121 * 3122 * The R_MACHINE_IRELATIVE slots are resolved in greedy fashion, 3123 * instead of the usual lazy handling of PLT slots. It is 3124 * consistent with how GNU does it. 3125 */ 3126 static int 3127 resolve_object_ifunc(Obj_Entry *obj, bool bind_now, int flags, 3128 RtldLockState *lockstate) 3129 { 3130 3131 if (obj->ifuncs_resolved) 3132 return (0); 3133 obj->ifuncs_resolved = true; 3134 if (!obj->irelative && !obj->irelative_nonplt && 3135 !((obj->bind_now || bind_now) && obj->gnu_ifunc) && 3136 !obj->non_plt_gnu_ifunc) 3137 return (0); 3138 if (obj_disable_relro(obj) == -1 || 3139 (obj->irelative && reloc_iresolve(obj, lockstate) == -1) || 3140 (obj->irelative_nonplt && reloc_iresolve_nonplt(obj, 3141 lockstate) == -1) || 3142 ((obj->bind_now || bind_now) && obj->gnu_ifunc && 3143 reloc_gnu_ifunc(obj, flags, lockstate) == -1) || 3144 (obj->non_plt_gnu_ifunc && reloc_non_plt(obj, &obj_rtld, 3145 flags | SYMLOOK_IFUNC, lockstate) == -1) || 3146 obj_enforce_relro(obj) == -1) 3147 return (-1); 3148 return (0); 3149 } 3150 3151 static int 3152 initlist_objects_ifunc(Objlist *list, bool bind_now, int flags, 3153 RtldLockState *lockstate) 3154 { 3155 Objlist_Entry *elm; 3156 Obj_Entry *obj; 3157 3158 STAILQ_FOREACH(elm, list, link) { 3159 obj = elm->obj; 3160 if (obj->marker) 3161 continue; 3162 if (resolve_object_ifunc(obj, bind_now, flags, 3163 lockstate) == -1) 3164 return (-1); 3165 } 3166 return (0); 3167 } 3168 3169 /* 3170 * Cleanup procedure. It will be called (by the atexit mechanism) just 3171 * before the process exits. 3172 */ 3173 static void 3174 rtld_exit(void) 3175 { 3176 RtldLockState lockstate; 3177 3178 wlock_acquire(rtld_bind_lock, &lockstate); 3179 dbg("rtld_exit()"); 3180 objlist_call_fini(&list_fini, NULL, &lockstate); 3181 /* No need to remove the items from the list, since we are exiting. */ 3182 if (!libmap_disable) 3183 lm_fini(); 3184 lock_release(rtld_bind_lock, &lockstate); 3185 } 3186 3187 static void 3188 rtld_nop_exit(void) 3189 { 3190 } 3191 3192 /* 3193 * Iterate over a search path, translate each element, and invoke the 3194 * callback on the result. 3195 */ 3196 static void * 3197 path_enumerate(const char *path, path_enum_proc callback, 3198 const char *refobj_path, void *arg) 3199 { 3200 const char *trans; 3201 if (path == NULL) 3202 return (NULL); 3203 3204 path += strspn(path, ":;"); 3205 while (*path != '\0') { 3206 size_t len; 3207 char *res; 3208 3209 len = strcspn(path, ":;"); 3210 trans = lm_findn(refobj_path, path, len); 3211 if (trans) 3212 res = callback(trans, strlen(trans), arg); 3213 else 3214 res = callback(path, len, arg); 3215 3216 if (res != NULL) 3217 return (res); 3218 3219 path += len; 3220 path += strspn(path, ":;"); 3221 } 3222 3223 return (NULL); 3224 } 3225 3226 struct try_library_args { 3227 const char *name; 3228 size_t namelen; 3229 char *buffer; 3230 size_t buflen; 3231 int fd; 3232 }; 3233 3234 static void * 3235 try_library_path(const char *dir, size_t dirlen, void *param) 3236 { 3237 struct try_library_args *arg; 3238 int fd; 3239 3240 arg = param; 3241 if (*dir == '/' || trust) { 3242 char *pathname; 3243 3244 if (dirlen + 1 + arg->namelen + 1 > arg->buflen) 3245 return (NULL); 3246 3247 pathname = arg->buffer; 3248 strncpy(pathname, dir, dirlen); 3249 pathname[dirlen] = '/'; 3250 strcpy(pathname + dirlen + 1, arg->name); 3251 3252 dbg(" Trying \"%s\"", pathname); 3253 fd = open(pathname, O_RDONLY | O_CLOEXEC | O_VERIFY); 3254 if (fd >= 0) { 3255 dbg(" Opened \"%s\", fd %d", pathname, fd); 3256 pathname = xmalloc(dirlen + 1 + arg->namelen + 1); 3257 strcpy(pathname, arg->buffer); 3258 arg->fd = fd; 3259 return (pathname); 3260 } else { 3261 dbg(" Failed to open \"%s\": %s", 3262 pathname, rtld_strerror(errno)); 3263 } 3264 } 3265 return (NULL); 3266 } 3267 3268 static char * 3269 search_library_path(const char *name, const char *path, 3270 const char *refobj_path, int *fdp) 3271 { 3272 char *p; 3273 struct try_library_args arg; 3274 3275 if (path == NULL) 3276 return NULL; 3277 3278 arg.name = name; 3279 arg.namelen = strlen(name); 3280 arg.buffer = xmalloc(PATH_MAX); 3281 arg.buflen = PATH_MAX; 3282 arg.fd = -1; 3283 3284 p = path_enumerate(path, try_library_path, refobj_path, &arg); 3285 *fdp = arg.fd; 3286 3287 free(arg.buffer); 3288 3289 return (p); 3290 } 3291 3292 3293 /* 3294 * Finds the library with the given name using the directory descriptors 3295 * listed in the LD_LIBRARY_PATH_FDS environment variable. 3296 * 3297 * Returns a freshly-opened close-on-exec file descriptor for the library, 3298 * or -1 if the library cannot be found. 3299 */ 3300 static char * 3301 search_library_pathfds(const char *name, const char *path, int *fdp) 3302 { 3303 char *envcopy, *fdstr, *found, *last_token; 3304 size_t len; 3305 int dirfd, fd; 3306 3307 dbg("%s('%s', '%s', fdp)", __func__, name, path); 3308 3309 /* Don't load from user-specified libdirs into setuid binaries. */ 3310 if (!trust) 3311 return (NULL); 3312 3313 /* We can't do anything if LD_LIBRARY_PATH_FDS isn't set. */ 3314 if (path == NULL) 3315 return (NULL); 3316 3317 /* LD_LIBRARY_PATH_FDS only works with relative paths. */ 3318 if (name[0] == '/') { 3319 dbg("Absolute path (%s) passed to %s", name, __func__); 3320 return (NULL); 3321 } 3322 3323 /* 3324 * Use strtok_r() to walk the FD:FD:FD list. This requires a local 3325 * copy of the path, as strtok_r rewrites separator tokens 3326 * with '\0'. 3327 */ 3328 found = NULL; 3329 envcopy = xstrdup(path); 3330 for (fdstr = strtok_r(envcopy, ":", &last_token); fdstr != NULL; 3331 fdstr = strtok_r(NULL, ":", &last_token)) { 3332 dirfd = parse_integer(fdstr); 3333 if (dirfd < 0) { 3334 _rtld_error("failed to parse directory FD: '%s'", 3335 fdstr); 3336 break; 3337 } 3338 fd = __sys_openat(dirfd, name, O_RDONLY | O_CLOEXEC | O_VERIFY); 3339 if (fd >= 0) { 3340 *fdp = fd; 3341 len = strlen(fdstr) + strlen(name) + 3; 3342 found = xmalloc(len); 3343 if (rtld_snprintf(found, len, "#%d/%s", dirfd, name) < 0) { 3344 _rtld_error("error generating '%d/%s'", 3345 dirfd, name); 3346 rtld_die(); 3347 } 3348 dbg("open('%s') => %d", found, fd); 3349 break; 3350 } 3351 } 3352 free(envcopy); 3353 3354 return (found); 3355 } 3356 3357 3358 int 3359 dlclose(void *handle) 3360 { 3361 RtldLockState lockstate; 3362 int error; 3363 3364 wlock_acquire(rtld_bind_lock, &lockstate); 3365 error = dlclose_locked(handle, &lockstate); 3366 lock_release(rtld_bind_lock, &lockstate); 3367 return (error); 3368 } 3369 3370 static int 3371 dlclose_locked(void *handle, RtldLockState *lockstate) 3372 { 3373 Obj_Entry *root; 3374 3375 root = dlcheck(handle); 3376 if (root == NULL) 3377 return -1; 3378 LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount, 3379 root->path); 3380 3381 /* Unreference the object and its dependencies. */ 3382 root->dl_refcount--; 3383 3384 if (root->refcount == 1) { 3385 /* 3386 * The object will be no longer referenced, so we must unload it. 3387 * First, call the fini functions. 3388 */ 3389 objlist_call_fini(&list_fini, root, lockstate); 3390 3391 unref_dag(root); 3392 3393 /* Finish cleaning up the newly-unreferenced objects. */ 3394 GDB_STATE(RT_DELETE,&root->linkmap); 3395 unload_object(root, lockstate); 3396 GDB_STATE(RT_CONSISTENT,NULL); 3397 } else 3398 unref_dag(root); 3399 3400 LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL); 3401 return 0; 3402 } 3403 3404 char * 3405 dlerror(void) 3406 { 3407 if (*(lockinfo.dlerror_seen()) != 0) 3408 return (NULL); 3409 *lockinfo.dlerror_seen() = 1; 3410 return (lockinfo.dlerror_loc()); 3411 } 3412 3413 /* 3414 * This function is deprecated and has no effect. 3415 */ 3416 void 3417 dllockinit(void *context, 3418 void *(*_lock_create)(void *context) __unused, 3419 void (*_rlock_acquire)(void *lock) __unused, 3420 void (*_wlock_acquire)(void *lock) __unused, 3421 void (*_lock_release)(void *lock) __unused, 3422 void (*_lock_destroy)(void *lock) __unused, 3423 void (*context_destroy)(void *context)) 3424 { 3425 static void *cur_context; 3426 static void (*cur_context_destroy)(void *); 3427 3428 /* Just destroy the context from the previous call, if necessary. */ 3429 if (cur_context_destroy != NULL) 3430 cur_context_destroy(cur_context); 3431 cur_context = context; 3432 cur_context_destroy = context_destroy; 3433 } 3434 3435 void * 3436 dlopen(const char *name, int mode) 3437 { 3438 3439 return (rtld_dlopen(name, -1, mode)); 3440 } 3441 3442 void * 3443 fdlopen(int fd, int mode) 3444 { 3445 3446 return (rtld_dlopen(NULL, fd, mode)); 3447 } 3448 3449 static void * 3450 rtld_dlopen(const char *name, int fd, int mode) 3451 { 3452 RtldLockState lockstate; 3453 int lo_flags; 3454 3455 LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name); 3456 ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1"; 3457 if (ld_tracing != NULL) { 3458 rlock_acquire(rtld_bind_lock, &lockstate); 3459 if (sigsetjmp(lockstate.env, 0) != 0) 3460 lock_upgrade(rtld_bind_lock, &lockstate); 3461 environ = __DECONST(char **, *get_program_var_addr("environ", &lockstate)); 3462 lock_release(rtld_bind_lock, &lockstate); 3463 } 3464 lo_flags = RTLD_LO_DLOPEN; 3465 if (mode & RTLD_NODELETE) 3466 lo_flags |= RTLD_LO_NODELETE; 3467 if (mode & RTLD_NOLOAD) 3468 lo_flags |= RTLD_LO_NOLOAD; 3469 if (mode & RTLD_DEEPBIND) 3470 lo_flags |= RTLD_LO_DEEPBIND; 3471 if (ld_tracing != NULL) 3472 lo_flags |= RTLD_LO_TRACE | RTLD_LO_IGNSTLS; 3473 3474 return (dlopen_object(name, fd, obj_main, lo_flags, 3475 mode & (RTLD_MODEMASK | RTLD_GLOBAL), NULL)); 3476 } 3477 3478 static void 3479 dlopen_cleanup(Obj_Entry *obj, RtldLockState *lockstate) 3480 { 3481 3482 obj->dl_refcount--; 3483 unref_dag(obj); 3484 if (obj->refcount == 0) 3485 unload_object(obj, lockstate); 3486 } 3487 3488 static Obj_Entry * 3489 dlopen_object(const char *name, int fd, Obj_Entry *refobj, int lo_flags, 3490 int mode, RtldLockState *lockstate) 3491 { 3492 Obj_Entry *old_obj_tail; 3493 Obj_Entry *obj; 3494 Objlist initlist; 3495 RtldLockState mlockstate; 3496 int result; 3497 3498 dbg("dlopen_object name \"%s\" fd %d refobj \"%s\" lo_flags %#x mode %#x", 3499 name != NULL ? name : "<null>", fd, refobj == NULL ? "<null>" : 3500 refobj->path, lo_flags, mode); 3501 objlist_init(&initlist); 3502 3503 if (lockstate == NULL && !(lo_flags & RTLD_LO_EARLY)) { 3504 wlock_acquire(rtld_bind_lock, &mlockstate); 3505 lockstate = &mlockstate; 3506 } 3507 GDB_STATE(RT_ADD,NULL); 3508 3509 old_obj_tail = globallist_curr(TAILQ_LAST(&obj_list, obj_entry_q)); 3510 obj = NULL; 3511 if (name == NULL && fd == -1) { 3512 obj = obj_main; 3513 obj->refcount++; 3514 } else { 3515 obj = load_object(name, fd, refobj, lo_flags); 3516 } 3517 3518 if (obj) { 3519 obj->dl_refcount++; 3520 if (mode & RTLD_GLOBAL && objlist_find(&list_global, obj) == NULL) 3521 objlist_push_tail(&list_global, obj); 3522 if (globallist_next(old_obj_tail) != NULL) { 3523 /* We loaded something new. */ 3524 assert(globallist_next(old_obj_tail) == obj); 3525 if ((lo_flags & RTLD_LO_DEEPBIND) != 0) 3526 obj->symbolic = true; 3527 result = 0; 3528 if ((lo_flags & (RTLD_LO_EARLY | RTLD_LO_IGNSTLS)) == 0 && 3529 obj->static_tls && !allocate_tls_offset(obj)) { 3530 _rtld_error("%s: No space available " 3531 "for static Thread Local Storage", obj->path); 3532 result = -1; 3533 } 3534 if (result != -1) 3535 result = load_needed_objects(obj, lo_flags & (RTLD_LO_DLOPEN | 3536 RTLD_LO_EARLY | RTLD_LO_IGNSTLS | RTLD_LO_TRACE)); 3537 init_dag(obj); 3538 ref_dag(obj); 3539 if (result != -1) 3540 result = rtld_verify_versions(&obj->dagmembers); 3541 if (result != -1 && ld_tracing) 3542 goto trace; 3543 if (result == -1 || relocate_object_dag(obj, 3544 (mode & RTLD_MODEMASK) == RTLD_NOW, &obj_rtld, 3545 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 3546 lockstate) == -1) { 3547 dlopen_cleanup(obj, lockstate); 3548 obj = NULL; 3549 } else if (lo_flags & RTLD_LO_EARLY) { 3550 /* 3551 * Do not call the init functions for early loaded 3552 * filtees. The image is still not initialized enough 3553 * for them to work. 3554 * 3555 * Our object is found by the global object list and 3556 * will be ordered among all init calls done right 3557 * before transferring control to main. 3558 */ 3559 } else { 3560 /* Make list of init functions to call. */ 3561 initlist_add_objects(obj, obj, &initlist); 3562 } 3563 /* 3564 * Process all no_delete or global objects here, given 3565 * them own DAGs to prevent their dependencies from being 3566 * unloaded. This has to be done after we have loaded all 3567 * of the dependencies, so that we do not miss any. 3568 */ 3569 if (obj != NULL) 3570 process_z(obj); 3571 } else { 3572 /* 3573 * Bump the reference counts for objects on this DAG. If 3574 * this is the first dlopen() call for the object that was 3575 * already loaded as a dependency, initialize the dag 3576 * starting at it. 3577 */ 3578 init_dag(obj); 3579 ref_dag(obj); 3580 3581 if ((lo_flags & RTLD_LO_TRACE) != 0) 3582 goto trace; 3583 } 3584 if (obj != NULL && ((lo_flags & RTLD_LO_NODELETE) != 0 || 3585 obj->z_nodelete) && !obj->ref_nodel) { 3586 dbg("obj %s nodelete", obj->path); 3587 ref_dag(obj); 3588 obj->z_nodelete = obj->ref_nodel = true; 3589 } 3590 } 3591 3592 LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0, 3593 name); 3594 GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL); 3595 3596 if ((lo_flags & RTLD_LO_EARLY) == 0) { 3597 map_stacks_exec(lockstate); 3598 if (obj != NULL) 3599 distribute_static_tls(&initlist, lockstate); 3600 } 3601 3602 if (initlist_objects_ifunc(&initlist, (mode & RTLD_MODEMASK) == RTLD_NOW, 3603 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 3604 lockstate) == -1) { 3605 objlist_clear(&initlist); 3606 dlopen_cleanup(obj, lockstate); 3607 if (lockstate == &mlockstate) 3608 lock_release(rtld_bind_lock, lockstate); 3609 return (NULL); 3610 } 3611 3612 if (!(lo_flags & RTLD_LO_EARLY)) { 3613 /* Call the init functions. */ 3614 objlist_call_init(&initlist, lockstate); 3615 } 3616 objlist_clear(&initlist); 3617 if (lockstate == &mlockstate) 3618 lock_release(rtld_bind_lock, lockstate); 3619 return obj; 3620 trace: 3621 trace_loaded_objects(obj); 3622 if (lockstate == &mlockstate) 3623 lock_release(rtld_bind_lock, lockstate); 3624 exit(0); 3625 } 3626 3627 static void * 3628 do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve, 3629 int flags) 3630 { 3631 DoneList donelist; 3632 const Obj_Entry *obj, *defobj; 3633 const Elf_Sym *def; 3634 SymLook req; 3635 RtldLockState lockstate; 3636 tls_index ti; 3637 void *sym; 3638 int res; 3639 3640 def = NULL; 3641 defobj = NULL; 3642 symlook_init(&req, name); 3643 req.ventry = ve; 3644 req.flags = flags | SYMLOOK_IN_PLT; 3645 req.lockstate = &lockstate; 3646 3647 LD_UTRACE(UTRACE_DLSYM_START, handle, NULL, 0, 0, name); 3648 rlock_acquire(rtld_bind_lock, &lockstate); 3649 if (sigsetjmp(lockstate.env, 0) != 0) 3650 lock_upgrade(rtld_bind_lock, &lockstate); 3651 if (handle == NULL || handle == RTLD_NEXT || 3652 handle == RTLD_DEFAULT || handle == RTLD_SELF) { 3653 3654 if ((obj = obj_from_addr(retaddr)) == NULL) { 3655 _rtld_error("Cannot determine caller's shared object"); 3656 lock_release(rtld_bind_lock, &lockstate); 3657 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 3658 return NULL; 3659 } 3660 if (handle == NULL) { /* Just the caller's shared object. */ 3661 res = symlook_obj(&req, obj); 3662 if (res == 0) { 3663 def = req.sym_out; 3664 defobj = req.defobj_out; 3665 } 3666 } else if (handle == RTLD_NEXT || /* Objects after caller's */ 3667 handle == RTLD_SELF) { /* ... caller included */ 3668 if (handle == RTLD_NEXT) 3669 obj = globallist_next(obj); 3670 for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 3671 if (obj->marker) 3672 continue; 3673 res = symlook_obj(&req, obj); 3674 if (res == 0) { 3675 if (def == NULL || 3676 ELF_ST_BIND(req.sym_out->st_info) != STB_WEAK) { 3677 def = req.sym_out; 3678 defobj = req.defobj_out; 3679 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 3680 break; 3681 } 3682 } 3683 } 3684 /* 3685 * Search the dynamic linker itself, and possibly resolve the 3686 * symbol from there. This is how the application links to 3687 * dynamic linker services such as dlopen. 3688 */ 3689 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 3690 res = symlook_obj(&req, &obj_rtld); 3691 if (res == 0) { 3692 def = req.sym_out; 3693 defobj = req.defobj_out; 3694 } 3695 } 3696 } else { 3697 assert(handle == RTLD_DEFAULT); 3698 res = symlook_default(&req, obj); 3699 if (res == 0) { 3700 defobj = req.defobj_out; 3701 def = req.sym_out; 3702 } 3703 } 3704 } else { 3705 if ((obj = dlcheck(handle)) == NULL) { 3706 lock_release(rtld_bind_lock, &lockstate); 3707 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 3708 return NULL; 3709 } 3710 3711 donelist_init(&donelist); 3712 if (obj->mainprog) { 3713 /* Handle obtained by dlopen(NULL, ...) implies global scope. */ 3714 res = symlook_global(&req, &donelist); 3715 if (res == 0) { 3716 def = req.sym_out; 3717 defobj = req.defobj_out; 3718 } 3719 /* 3720 * Search the dynamic linker itself, and possibly resolve the 3721 * symbol from there. This is how the application links to 3722 * dynamic linker services such as dlopen. 3723 */ 3724 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 3725 res = symlook_obj(&req, &obj_rtld); 3726 if (res == 0) { 3727 def = req.sym_out; 3728 defobj = req.defobj_out; 3729 } 3730 } 3731 } 3732 else { 3733 /* Search the whole DAG rooted at the given object. */ 3734 res = symlook_list(&req, &obj->dagmembers, &donelist); 3735 if (res == 0) { 3736 def = req.sym_out; 3737 defobj = req.defobj_out; 3738 } 3739 } 3740 } 3741 3742 if (def != NULL) { 3743 lock_release(rtld_bind_lock, &lockstate); 3744 3745 /* 3746 * The value required by the caller is derived from the value 3747 * of the symbol. this is simply the relocated value of the 3748 * symbol. 3749 */ 3750 if (ELF_ST_TYPE(def->st_info) == STT_FUNC) 3751 sym = make_function_pointer(def, defobj); 3752 else if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 3753 sym = rtld_resolve_ifunc(defobj, def); 3754 else if (ELF_ST_TYPE(def->st_info) == STT_TLS) { 3755 ti.ti_module = defobj->tlsindex; 3756 ti.ti_offset = def->st_value; 3757 sym = __tls_get_addr(&ti); 3758 } else 3759 sym = defobj->relocbase + def->st_value; 3760 LD_UTRACE(UTRACE_DLSYM_STOP, handle, sym, 0, 0, name); 3761 return (sym); 3762 } 3763 3764 _rtld_error("Undefined symbol \"%s%s%s\"", name, ve != NULL ? "@" : "", 3765 ve != NULL ? ve->name : ""); 3766 lock_release(rtld_bind_lock, &lockstate); 3767 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 3768 return NULL; 3769 } 3770 3771 void * 3772 dlsym(void *handle, const char *name) 3773 { 3774 return do_dlsym(handle, name, __builtin_return_address(0), NULL, 3775 SYMLOOK_DLSYM); 3776 } 3777 3778 dlfunc_t 3779 dlfunc(void *handle, const char *name) 3780 { 3781 union { 3782 void *d; 3783 dlfunc_t f; 3784 } rv; 3785 3786 rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL, 3787 SYMLOOK_DLSYM); 3788 return (rv.f); 3789 } 3790 3791 void * 3792 dlvsym(void *handle, const char *name, const char *version) 3793 { 3794 Ver_Entry ventry; 3795 3796 ventry.name = version; 3797 ventry.file = NULL; 3798 ventry.hash = elf_hash(version); 3799 ventry.flags= 0; 3800 return do_dlsym(handle, name, __builtin_return_address(0), &ventry, 3801 SYMLOOK_DLSYM); 3802 } 3803 3804 int 3805 _rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info) 3806 { 3807 const Obj_Entry *obj; 3808 RtldLockState lockstate; 3809 3810 rlock_acquire(rtld_bind_lock, &lockstate); 3811 obj = obj_from_addr(addr); 3812 if (obj == NULL) { 3813 _rtld_error("No shared object contains address"); 3814 lock_release(rtld_bind_lock, &lockstate); 3815 return (0); 3816 } 3817 rtld_fill_dl_phdr_info(obj, phdr_info); 3818 lock_release(rtld_bind_lock, &lockstate); 3819 return (1); 3820 } 3821 3822 int 3823 dladdr(const void *addr, Dl_info *info) 3824 { 3825 const Obj_Entry *obj; 3826 const Elf_Sym *def; 3827 void *symbol_addr; 3828 unsigned long symoffset; 3829 RtldLockState lockstate; 3830 3831 rlock_acquire(rtld_bind_lock, &lockstate); 3832 obj = obj_from_addr(addr); 3833 if (obj == NULL) { 3834 _rtld_error("No shared object contains address"); 3835 lock_release(rtld_bind_lock, &lockstate); 3836 return 0; 3837 } 3838 info->dli_fname = obj->path; 3839 info->dli_fbase = obj->mapbase; 3840 info->dli_saddr = (void *)0; 3841 info->dli_sname = NULL; 3842 3843 /* 3844 * Walk the symbol list looking for the symbol whose address is 3845 * closest to the address sent in. 3846 */ 3847 for (symoffset = 0; symoffset < obj->dynsymcount; symoffset++) { 3848 def = obj->symtab + symoffset; 3849 3850 /* 3851 * For skip the symbol if st_shndx is either SHN_UNDEF or 3852 * SHN_COMMON. 3853 */ 3854 if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON) 3855 continue; 3856 3857 /* 3858 * If the symbol is greater than the specified address, or if it 3859 * is further away from addr than the current nearest symbol, 3860 * then reject it. 3861 */ 3862 symbol_addr = obj->relocbase + def->st_value; 3863 if (symbol_addr > addr || symbol_addr < info->dli_saddr) 3864 continue; 3865 3866 /* Update our idea of the nearest symbol. */ 3867 info->dli_sname = obj->strtab + def->st_name; 3868 info->dli_saddr = symbol_addr; 3869 3870 /* Exact match? */ 3871 if (info->dli_saddr == addr) 3872 break; 3873 } 3874 lock_release(rtld_bind_lock, &lockstate); 3875 return 1; 3876 } 3877 3878 int 3879 dlinfo(void *handle, int request, void *p) 3880 { 3881 const Obj_Entry *obj; 3882 RtldLockState lockstate; 3883 int error; 3884 3885 rlock_acquire(rtld_bind_lock, &lockstate); 3886 3887 if (handle == NULL || handle == RTLD_SELF) { 3888 void *retaddr; 3889 3890 retaddr = __builtin_return_address(0); /* __GNUC__ only */ 3891 if ((obj = obj_from_addr(retaddr)) == NULL) 3892 _rtld_error("Cannot determine caller's shared object"); 3893 } else 3894 obj = dlcheck(handle); 3895 3896 if (obj == NULL) { 3897 lock_release(rtld_bind_lock, &lockstate); 3898 return (-1); 3899 } 3900 3901 error = 0; 3902 switch (request) { 3903 case RTLD_DI_LINKMAP: 3904 *((struct link_map const **)p) = &obj->linkmap; 3905 break; 3906 case RTLD_DI_ORIGIN: 3907 error = rtld_dirname(obj->path, p); 3908 break; 3909 3910 case RTLD_DI_SERINFOSIZE: 3911 case RTLD_DI_SERINFO: 3912 error = do_search_info(obj, request, (struct dl_serinfo *)p); 3913 break; 3914 3915 default: 3916 _rtld_error("Invalid request %d passed to dlinfo()", request); 3917 error = -1; 3918 } 3919 3920 lock_release(rtld_bind_lock, &lockstate); 3921 3922 return (error); 3923 } 3924 3925 static void 3926 rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info) 3927 { 3928 Elf_Addr **dtvp; 3929 3930 phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase; 3931 phdr_info->dlpi_name = obj->path; 3932 phdr_info->dlpi_phdr = obj->phdr; 3933 phdr_info->dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]); 3934 phdr_info->dlpi_tls_modid = obj->tlsindex; 3935 dtvp = _get_tp(); 3936 phdr_info->dlpi_tls_data = (char *)tls_get_addr_slow(dtvp, 3937 obj->tlsindex, 0, true) + TLS_DTV_OFFSET; 3938 phdr_info->dlpi_adds = obj_loads; 3939 phdr_info->dlpi_subs = obj_loads - obj_count; 3940 } 3941 3942 int 3943 dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param) 3944 { 3945 struct dl_phdr_info phdr_info; 3946 Obj_Entry *obj, marker; 3947 RtldLockState bind_lockstate, phdr_lockstate; 3948 int error; 3949 3950 init_marker(&marker); 3951 error = 0; 3952 3953 wlock_acquire(rtld_phdr_lock, &phdr_lockstate); 3954 wlock_acquire(rtld_bind_lock, &bind_lockstate); 3955 for (obj = globallist_curr(TAILQ_FIRST(&obj_list)); obj != NULL;) { 3956 TAILQ_INSERT_AFTER(&obj_list, obj, &marker, next); 3957 rtld_fill_dl_phdr_info(obj, &phdr_info); 3958 hold_object(obj); 3959 lock_release(rtld_bind_lock, &bind_lockstate); 3960 3961 error = callback(&phdr_info, sizeof phdr_info, param); 3962 3963 wlock_acquire(rtld_bind_lock, &bind_lockstate); 3964 unhold_object(obj); 3965 obj = globallist_next(&marker); 3966 TAILQ_REMOVE(&obj_list, &marker, next); 3967 if (error != 0) { 3968 lock_release(rtld_bind_lock, &bind_lockstate); 3969 lock_release(rtld_phdr_lock, &phdr_lockstate); 3970 return (error); 3971 } 3972 } 3973 3974 if (error == 0) { 3975 rtld_fill_dl_phdr_info(&obj_rtld, &phdr_info); 3976 lock_release(rtld_bind_lock, &bind_lockstate); 3977 error = callback(&phdr_info, sizeof(phdr_info), param); 3978 } 3979 lock_release(rtld_phdr_lock, &phdr_lockstate); 3980 return (error); 3981 } 3982 3983 static void * 3984 fill_search_info(const char *dir, size_t dirlen, void *param) 3985 { 3986 struct fill_search_info_args *arg; 3987 3988 arg = param; 3989 3990 if (arg->request == RTLD_DI_SERINFOSIZE) { 3991 arg->serinfo->dls_cnt ++; 3992 arg->serinfo->dls_size += sizeof(struct dl_serpath) + dirlen + 1; 3993 } else { 3994 struct dl_serpath *s_entry; 3995 3996 s_entry = arg->serpath; 3997 s_entry->dls_name = arg->strspace; 3998 s_entry->dls_flags = arg->flags; 3999 4000 strncpy(arg->strspace, dir, dirlen); 4001 arg->strspace[dirlen] = '\0'; 4002 4003 arg->strspace += dirlen + 1; 4004 arg->serpath++; 4005 } 4006 4007 return (NULL); 4008 } 4009 4010 static int 4011 do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info) 4012 { 4013 struct dl_serinfo _info; 4014 struct fill_search_info_args args; 4015 4016 args.request = RTLD_DI_SERINFOSIZE; 4017 args.serinfo = &_info; 4018 4019 _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 4020 _info.dls_cnt = 0; 4021 4022 path_enumerate(obj->rpath, fill_search_info, NULL, &args); 4023 path_enumerate(ld_library_path, fill_search_info, NULL, &args); 4024 path_enumerate(obj->runpath, fill_search_info, NULL, &args); 4025 path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, &args); 4026 if (!obj->z_nodeflib) 4027 path_enumerate(ld_standard_library_path, fill_search_info, NULL, &args); 4028 4029 4030 if (request == RTLD_DI_SERINFOSIZE) { 4031 info->dls_size = _info.dls_size; 4032 info->dls_cnt = _info.dls_cnt; 4033 return (0); 4034 } 4035 4036 if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) { 4037 _rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()"); 4038 return (-1); 4039 } 4040 4041 args.request = RTLD_DI_SERINFO; 4042 args.serinfo = info; 4043 args.serpath = &info->dls_serpath[0]; 4044 args.strspace = (char *)&info->dls_serpath[_info.dls_cnt]; 4045 4046 args.flags = LA_SER_RUNPATH; 4047 if (path_enumerate(obj->rpath, fill_search_info, NULL, &args) != NULL) 4048 return (-1); 4049 4050 args.flags = LA_SER_LIBPATH; 4051 if (path_enumerate(ld_library_path, fill_search_info, NULL, &args) != NULL) 4052 return (-1); 4053 4054 args.flags = LA_SER_RUNPATH; 4055 if (path_enumerate(obj->runpath, fill_search_info, NULL, &args) != NULL) 4056 return (-1); 4057 4058 args.flags = LA_SER_CONFIG; 4059 if (path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, &args) 4060 != NULL) 4061 return (-1); 4062 4063 args.flags = LA_SER_DEFAULT; 4064 if (!obj->z_nodeflib && path_enumerate(ld_standard_library_path, 4065 fill_search_info, NULL, &args) != NULL) 4066 return (-1); 4067 return (0); 4068 } 4069 4070 static int 4071 rtld_dirname(const char *path, char *bname) 4072 { 4073 const char *endp; 4074 4075 /* Empty or NULL string gets treated as "." */ 4076 if (path == NULL || *path == '\0') { 4077 bname[0] = '.'; 4078 bname[1] = '\0'; 4079 return (0); 4080 } 4081 4082 /* Strip trailing slashes */ 4083 endp = path + strlen(path) - 1; 4084 while (endp > path && *endp == '/') 4085 endp--; 4086 4087 /* Find the start of the dir */ 4088 while (endp > path && *endp != '/') 4089 endp--; 4090 4091 /* Either the dir is "/" or there are no slashes */ 4092 if (endp == path) { 4093 bname[0] = *endp == '/' ? '/' : '.'; 4094 bname[1] = '\0'; 4095 return (0); 4096 } else { 4097 do { 4098 endp--; 4099 } while (endp > path && *endp == '/'); 4100 } 4101 4102 if (endp - path + 2 > PATH_MAX) 4103 { 4104 _rtld_error("Filename is too long: %s", path); 4105 return(-1); 4106 } 4107 4108 strncpy(bname, path, endp - path + 1); 4109 bname[endp - path + 1] = '\0'; 4110 return (0); 4111 } 4112 4113 static int 4114 rtld_dirname_abs(const char *path, char *base) 4115 { 4116 char *last; 4117 4118 if (realpath(path, base) == NULL) { 4119 _rtld_error("realpath \"%s\" failed (%s)", path, 4120 rtld_strerror(errno)); 4121 return (-1); 4122 } 4123 dbg("%s -> %s", path, base); 4124 last = strrchr(base, '/'); 4125 if (last == NULL) { 4126 _rtld_error("non-abs result from realpath \"%s\"", path); 4127 return (-1); 4128 } 4129 if (last != base) 4130 *last = '\0'; 4131 return (0); 4132 } 4133 4134 static void 4135 linkmap_add(Obj_Entry *obj) 4136 { 4137 struct link_map *l, *prev; 4138 4139 l = &obj->linkmap; 4140 l->l_name = obj->path; 4141 l->l_base = obj->mapbase; 4142 l->l_ld = obj->dynamic; 4143 l->l_addr = obj->relocbase; 4144 4145 if (r_debug.r_map == NULL) { 4146 r_debug.r_map = l; 4147 return; 4148 } 4149 4150 /* 4151 * Scan to the end of the list, but not past the entry for the 4152 * dynamic linker, which we want to keep at the very end. 4153 */ 4154 for (prev = r_debug.r_map; 4155 prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap; 4156 prev = prev->l_next) 4157 ; 4158 4159 /* Link in the new entry. */ 4160 l->l_prev = prev; 4161 l->l_next = prev->l_next; 4162 if (l->l_next != NULL) 4163 l->l_next->l_prev = l; 4164 prev->l_next = l; 4165 } 4166 4167 static void 4168 linkmap_delete(Obj_Entry *obj) 4169 { 4170 struct link_map *l; 4171 4172 l = &obj->linkmap; 4173 if (l->l_prev == NULL) { 4174 if ((r_debug.r_map = l->l_next) != NULL) 4175 l->l_next->l_prev = NULL; 4176 return; 4177 } 4178 4179 if ((l->l_prev->l_next = l->l_next) != NULL) 4180 l->l_next->l_prev = l->l_prev; 4181 } 4182 4183 /* 4184 * Function for the debugger to set a breakpoint on to gain control. 4185 * 4186 * The two parameters allow the debugger to easily find and determine 4187 * what the runtime loader is doing and to whom it is doing it. 4188 * 4189 * When the loadhook trap is hit (r_debug_state, set at program 4190 * initialization), the arguments can be found on the stack: 4191 * 4192 * +8 struct link_map *m 4193 * +4 struct r_debug *rd 4194 * +0 RetAddr 4195 */ 4196 void 4197 r_debug_state(struct r_debug* rd __unused, struct link_map *m __unused) 4198 { 4199 /* 4200 * The following is a hack to force the compiler to emit calls to 4201 * this function, even when optimizing. If the function is empty, 4202 * the compiler is not obliged to emit any code for calls to it, 4203 * even when marked __noinline. However, gdb depends on those 4204 * calls being made. 4205 */ 4206 __compiler_membar(); 4207 } 4208 4209 /* 4210 * A function called after init routines have completed. This can be used to 4211 * break before a program's entry routine is called, and can be used when 4212 * main is not available in the symbol table. 4213 */ 4214 void 4215 _r_debug_postinit(struct link_map *m __unused) 4216 { 4217 4218 /* See r_debug_state(). */ 4219 __compiler_membar(); 4220 } 4221 4222 static void 4223 release_object(Obj_Entry *obj) 4224 { 4225 4226 if (obj->holdcount > 0) { 4227 obj->unholdfree = true; 4228 return; 4229 } 4230 munmap(obj->mapbase, obj->mapsize); 4231 linkmap_delete(obj); 4232 obj_free(obj); 4233 } 4234 4235 /* 4236 * Get address of the pointer variable in the main program. 4237 * Prefer non-weak symbol over the weak one. 4238 */ 4239 static const void ** 4240 get_program_var_addr(const char *name, RtldLockState *lockstate) 4241 { 4242 SymLook req; 4243 DoneList donelist; 4244 4245 symlook_init(&req, name); 4246 req.lockstate = lockstate; 4247 donelist_init(&donelist); 4248 if (symlook_global(&req, &donelist) != 0) 4249 return (NULL); 4250 if (ELF_ST_TYPE(req.sym_out->st_info) == STT_FUNC) 4251 return ((const void **)make_function_pointer(req.sym_out, 4252 req.defobj_out)); 4253 else if (ELF_ST_TYPE(req.sym_out->st_info) == STT_GNU_IFUNC) 4254 return ((const void **)rtld_resolve_ifunc(req.defobj_out, req.sym_out)); 4255 else 4256 return ((const void **)(req.defobj_out->relocbase + 4257 req.sym_out->st_value)); 4258 } 4259 4260 /* 4261 * Set a pointer variable in the main program to the given value. This 4262 * is used to set key variables such as "environ" before any of the 4263 * init functions are called. 4264 */ 4265 static void 4266 set_program_var(const char *name, const void *value) 4267 { 4268 const void **addr; 4269 4270 if ((addr = get_program_var_addr(name, NULL)) != NULL) { 4271 dbg("\"%s\": *%p <-- %p", name, addr, value); 4272 *addr = value; 4273 } 4274 } 4275 4276 /* 4277 * Search the global objects, including dependencies and main object, 4278 * for the given symbol. 4279 */ 4280 static int 4281 symlook_global(SymLook *req, DoneList *donelist) 4282 { 4283 SymLook req1; 4284 const Objlist_Entry *elm; 4285 int res; 4286 4287 symlook_init_from_req(&req1, req); 4288 4289 /* Search all objects loaded at program start up. */ 4290 if (req->defobj_out == NULL || 4291 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 4292 res = symlook_list(&req1, &list_main, donelist); 4293 if (res == 0 && (req->defobj_out == NULL || 4294 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4295 req->sym_out = req1.sym_out; 4296 req->defobj_out = req1.defobj_out; 4297 assert(req->defobj_out != NULL); 4298 } 4299 } 4300 4301 /* Search all DAGs whose roots are RTLD_GLOBAL objects. */ 4302 STAILQ_FOREACH(elm, &list_global, link) { 4303 if (req->defobj_out != NULL && 4304 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK) 4305 break; 4306 res = symlook_list(&req1, &elm->obj->dagmembers, donelist); 4307 if (res == 0 && (req->defobj_out == NULL || 4308 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4309 req->sym_out = req1.sym_out; 4310 req->defobj_out = req1.defobj_out; 4311 assert(req->defobj_out != NULL); 4312 } 4313 } 4314 4315 return (req->sym_out != NULL ? 0 : ESRCH); 4316 } 4317 4318 /* 4319 * Given a symbol name in a referencing object, find the corresponding 4320 * definition of the symbol. Returns a pointer to the symbol, or NULL if 4321 * no definition was found. Returns a pointer to the Obj_Entry of the 4322 * defining object via the reference parameter DEFOBJ_OUT. 4323 */ 4324 static int 4325 symlook_default(SymLook *req, const Obj_Entry *refobj) 4326 { 4327 DoneList donelist; 4328 const Objlist_Entry *elm; 4329 SymLook req1; 4330 int res; 4331 4332 donelist_init(&donelist); 4333 symlook_init_from_req(&req1, req); 4334 4335 /* 4336 * Look first in the referencing object if linked symbolically, 4337 * and similarly handle protected symbols. 4338 */ 4339 res = symlook_obj(&req1, refobj); 4340 if (res == 0 && (refobj->symbolic || 4341 ELF_ST_VISIBILITY(req1.sym_out->st_other) == STV_PROTECTED)) { 4342 req->sym_out = req1.sym_out; 4343 req->defobj_out = req1.defobj_out; 4344 assert(req->defobj_out != NULL); 4345 } 4346 if (refobj->symbolic || req->defobj_out != NULL) 4347 donelist_check(&donelist, refobj); 4348 4349 symlook_global(req, &donelist); 4350 4351 /* Search all dlopened DAGs containing the referencing object. */ 4352 STAILQ_FOREACH(elm, &refobj->dldags, link) { 4353 if (req->sym_out != NULL && 4354 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK) 4355 break; 4356 res = symlook_list(&req1, &elm->obj->dagmembers, &donelist); 4357 if (res == 0 && (req->sym_out == NULL || 4358 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4359 req->sym_out = req1.sym_out; 4360 req->defobj_out = req1.defobj_out; 4361 assert(req->defobj_out != NULL); 4362 } 4363 } 4364 4365 /* 4366 * Search the dynamic linker itself, and possibly resolve the 4367 * symbol from there. This is how the application links to 4368 * dynamic linker services such as dlopen. 4369 */ 4370 if (req->sym_out == NULL || 4371 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 4372 res = symlook_obj(&req1, &obj_rtld); 4373 if (res == 0) { 4374 req->sym_out = req1.sym_out; 4375 req->defobj_out = req1.defobj_out; 4376 assert(req->defobj_out != NULL); 4377 } 4378 } 4379 4380 return (req->sym_out != NULL ? 0 : ESRCH); 4381 } 4382 4383 static int 4384 symlook_list(SymLook *req, const Objlist *objlist, DoneList *dlp) 4385 { 4386 const Elf_Sym *def; 4387 const Obj_Entry *defobj; 4388 const Objlist_Entry *elm; 4389 SymLook req1; 4390 int res; 4391 4392 def = NULL; 4393 defobj = NULL; 4394 STAILQ_FOREACH(elm, objlist, link) { 4395 if (donelist_check(dlp, elm->obj)) 4396 continue; 4397 symlook_init_from_req(&req1, req); 4398 if ((res = symlook_obj(&req1, elm->obj)) == 0) { 4399 if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) { 4400 def = req1.sym_out; 4401 defobj = req1.defobj_out; 4402 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 4403 break; 4404 } 4405 } 4406 } 4407 if (def != NULL) { 4408 req->sym_out = def; 4409 req->defobj_out = defobj; 4410 return (0); 4411 } 4412 return (ESRCH); 4413 } 4414 4415 /* 4416 * Search the chain of DAGS cointed to by the given Needed_Entry 4417 * for a symbol of the given name. Each DAG is scanned completely 4418 * before advancing to the next one. Returns a pointer to the symbol, 4419 * or NULL if no definition was found. 4420 */ 4421 static int 4422 symlook_needed(SymLook *req, const Needed_Entry *needed, DoneList *dlp) 4423 { 4424 const Elf_Sym *def; 4425 const Needed_Entry *n; 4426 const Obj_Entry *defobj; 4427 SymLook req1; 4428 int res; 4429 4430 def = NULL; 4431 defobj = NULL; 4432 symlook_init_from_req(&req1, req); 4433 for (n = needed; n != NULL; n = n->next) { 4434 if (n->obj == NULL || 4435 (res = symlook_list(&req1, &n->obj->dagmembers, dlp)) != 0) 4436 continue; 4437 if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) { 4438 def = req1.sym_out; 4439 defobj = req1.defobj_out; 4440 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 4441 break; 4442 } 4443 } 4444 if (def != NULL) { 4445 req->sym_out = def; 4446 req->defobj_out = defobj; 4447 return (0); 4448 } 4449 return (ESRCH); 4450 } 4451 4452 /* 4453 * Search the symbol table of a single shared object for a symbol of 4454 * the given name and version, if requested. Returns a pointer to the 4455 * symbol, or NULL if no definition was found. If the object is 4456 * filter, return filtered symbol from filtee. 4457 * 4458 * The symbol's hash value is passed in for efficiency reasons; that 4459 * eliminates many recomputations of the hash value. 4460 */ 4461 int 4462 symlook_obj(SymLook *req, const Obj_Entry *obj) 4463 { 4464 DoneList donelist; 4465 SymLook req1; 4466 int flags, res, mres; 4467 4468 /* 4469 * If there is at least one valid hash at this point, we prefer to 4470 * use the faster GNU version if available. 4471 */ 4472 if (obj->valid_hash_gnu) 4473 mres = symlook_obj1_gnu(req, obj); 4474 else if (obj->valid_hash_sysv) 4475 mres = symlook_obj1_sysv(req, obj); 4476 else 4477 return (EINVAL); 4478 4479 if (mres == 0) { 4480 if (obj->needed_filtees != NULL) { 4481 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; 4482 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 4483 donelist_init(&donelist); 4484 symlook_init_from_req(&req1, req); 4485 res = symlook_needed(&req1, obj->needed_filtees, &donelist); 4486 if (res == 0) { 4487 req->sym_out = req1.sym_out; 4488 req->defobj_out = req1.defobj_out; 4489 } 4490 return (res); 4491 } 4492 if (obj->needed_aux_filtees != NULL) { 4493 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; 4494 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 4495 donelist_init(&donelist); 4496 symlook_init_from_req(&req1, req); 4497 res = symlook_needed(&req1, obj->needed_aux_filtees, &donelist); 4498 if (res == 0) { 4499 req->sym_out = req1.sym_out; 4500 req->defobj_out = req1.defobj_out; 4501 return (res); 4502 } 4503 } 4504 } 4505 return (mres); 4506 } 4507 4508 /* Symbol match routine common to both hash functions */ 4509 static bool 4510 matched_symbol(SymLook *req, const Obj_Entry *obj, Sym_Match_Result *result, 4511 const unsigned long symnum) 4512 { 4513 Elf_Versym verndx; 4514 const Elf_Sym *symp; 4515 const char *strp; 4516 4517 symp = obj->symtab + symnum; 4518 strp = obj->strtab + symp->st_name; 4519 4520 switch (ELF_ST_TYPE(symp->st_info)) { 4521 case STT_FUNC: 4522 case STT_NOTYPE: 4523 case STT_OBJECT: 4524 case STT_COMMON: 4525 case STT_GNU_IFUNC: 4526 if (symp->st_value == 0) 4527 return (false); 4528 /* fallthrough */ 4529 case STT_TLS: 4530 if (symp->st_shndx != SHN_UNDEF) 4531 break; 4532 #ifndef __mips__ 4533 else if (((req->flags & SYMLOOK_IN_PLT) == 0) && 4534 (ELF_ST_TYPE(symp->st_info) == STT_FUNC)) 4535 break; 4536 #endif 4537 /* fallthrough */ 4538 default: 4539 return (false); 4540 } 4541 if (req->name[0] != strp[0] || strcmp(req->name, strp) != 0) 4542 return (false); 4543 4544 if (req->ventry == NULL) { 4545 if (obj->versyms != NULL) { 4546 verndx = VER_NDX(obj->versyms[symnum]); 4547 if (verndx > obj->vernum) { 4548 _rtld_error( 4549 "%s: symbol %s references wrong version %d", 4550 obj->path, obj->strtab + symnum, verndx); 4551 return (false); 4552 } 4553 /* 4554 * If we are not called from dlsym (i.e. this 4555 * is a normal relocation from unversioned 4556 * binary), accept the symbol immediately if 4557 * it happens to have first version after this 4558 * shared object became versioned. Otherwise, 4559 * if symbol is versioned and not hidden, 4560 * remember it. If it is the only symbol with 4561 * this name exported by the shared object, it 4562 * will be returned as a match by the calling 4563 * function. If symbol is global (verndx < 2) 4564 * accept it unconditionally. 4565 */ 4566 if ((req->flags & SYMLOOK_DLSYM) == 0 && 4567 verndx == VER_NDX_GIVEN) { 4568 result->sym_out = symp; 4569 return (true); 4570 } 4571 else if (verndx >= VER_NDX_GIVEN) { 4572 if ((obj->versyms[symnum] & VER_NDX_HIDDEN) 4573 == 0) { 4574 if (result->vsymp == NULL) 4575 result->vsymp = symp; 4576 result->vcount++; 4577 } 4578 return (false); 4579 } 4580 } 4581 result->sym_out = symp; 4582 return (true); 4583 } 4584 if (obj->versyms == NULL) { 4585 if (object_match_name(obj, req->ventry->name)) { 4586 _rtld_error("%s: object %s should provide version %s " 4587 "for symbol %s", obj_rtld.path, obj->path, 4588 req->ventry->name, obj->strtab + symnum); 4589 return (false); 4590 } 4591 } else { 4592 verndx = VER_NDX(obj->versyms[symnum]); 4593 if (verndx > obj->vernum) { 4594 _rtld_error("%s: symbol %s references wrong version %d", 4595 obj->path, obj->strtab + symnum, verndx); 4596 return (false); 4597 } 4598 if (obj->vertab[verndx].hash != req->ventry->hash || 4599 strcmp(obj->vertab[verndx].name, req->ventry->name)) { 4600 /* 4601 * Version does not match. Look if this is a 4602 * global symbol and if it is not hidden. If 4603 * global symbol (verndx < 2) is available, 4604 * use it. Do not return symbol if we are 4605 * called by dlvsym, because dlvsym looks for 4606 * a specific version and default one is not 4607 * what dlvsym wants. 4608 */ 4609 if ((req->flags & SYMLOOK_DLSYM) || 4610 (verndx >= VER_NDX_GIVEN) || 4611 (obj->versyms[symnum] & VER_NDX_HIDDEN)) 4612 return (false); 4613 } 4614 } 4615 result->sym_out = symp; 4616 return (true); 4617 } 4618 4619 /* 4620 * Search for symbol using SysV hash function. 4621 * obj->buckets is known not to be NULL at this point; the test for this was 4622 * performed with the obj->valid_hash_sysv assignment. 4623 */ 4624 static int 4625 symlook_obj1_sysv(SymLook *req, const Obj_Entry *obj) 4626 { 4627 unsigned long symnum; 4628 Sym_Match_Result matchres; 4629 4630 matchres.sym_out = NULL; 4631 matchres.vsymp = NULL; 4632 matchres.vcount = 0; 4633 4634 for (symnum = obj->buckets[req->hash % obj->nbuckets]; 4635 symnum != STN_UNDEF; symnum = obj->chains[symnum]) { 4636 if (symnum >= obj->nchains) 4637 return (ESRCH); /* Bad object */ 4638 4639 if (matched_symbol(req, obj, &matchres, symnum)) { 4640 req->sym_out = matchres.sym_out; 4641 req->defobj_out = obj; 4642 return (0); 4643 } 4644 } 4645 if (matchres.vcount == 1) { 4646 req->sym_out = matchres.vsymp; 4647 req->defobj_out = obj; 4648 return (0); 4649 } 4650 return (ESRCH); 4651 } 4652 4653 /* Search for symbol using GNU hash function */ 4654 static int 4655 symlook_obj1_gnu(SymLook *req, const Obj_Entry *obj) 4656 { 4657 Elf_Addr bloom_word; 4658 const Elf32_Word *hashval; 4659 Elf32_Word bucket; 4660 Sym_Match_Result matchres; 4661 unsigned int h1, h2; 4662 unsigned long symnum; 4663 4664 matchres.sym_out = NULL; 4665 matchres.vsymp = NULL; 4666 matchres.vcount = 0; 4667 4668 /* Pick right bitmask word from Bloom filter array */ 4669 bloom_word = obj->bloom_gnu[(req->hash_gnu / __ELF_WORD_SIZE) & 4670 obj->maskwords_bm_gnu]; 4671 4672 /* Calculate modulus word size of gnu hash and its derivative */ 4673 h1 = req->hash_gnu & (__ELF_WORD_SIZE - 1); 4674 h2 = ((req->hash_gnu >> obj->shift2_gnu) & (__ELF_WORD_SIZE - 1)); 4675 4676 /* Filter out the "definitely not in set" queries */ 4677 if (((bloom_word >> h1) & (bloom_word >> h2) & 1) == 0) 4678 return (ESRCH); 4679 4680 /* Locate hash chain and corresponding value element*/ 4681 bucket = obj->buckets_gnu[req->hash_gnu % obj->nbuckets_gnu]; 4682 if (bucket == 0) 4683 return (ESRCH); 4684 hashval = &obj->chain_zero_gnu[bucket]; 4685 do { 4686 if (((*hashval ^ req->hash_gnu) >> 1) == 0) { 4687 symnum = hashval - obj->chain_zero_gnu; 4688 if (matched_symbol(req, obj, &matchres, symnum)) { 4689 req->sym_out = matchres.sym_out; 4690 req->defobj_out = obj; 4691 return (0); 4692 } 4693 } 4694 } while ((*hashval++ & 1) == 0); 4695 if (matchres.vcount == 1) { 4696 req->sym_out = matchres.vsymp; 4697 req->defobj_out = obj; 4698 return (0); 4699 } 4700 return (ESRCH); 4701 } 4702 4703 static void 4704 trace_loaded_objects(Obj_Entry *obj) 4705 { 4706 const char *fmt1, *fmt2, *fmt, *main_local, *list_containers; 4707 int c; 4708 4709 if ((main_local = getenv(_LD("TRACE_LOADED_OBJECTS_PROGNAME"))) == NULL) 4710 main_local = ""; 4711 4712 if ((fmt1 = getenv(_LD("TRACE_LOADED_OBJECTS_FMT1"))) == NULL) 4713 fmt1 = "\t%o => %p (%x)\n"; 4714 4715 if ((fmt2 = getenv(_LD("TRACE_LOADED_OBJECTS_FMT2"))) == NULL) 4716 fmt2 = "\t%o (%x)\n"; 4717 4718 list_containers = getenv(_LD("TRACE_LOADED_OBJECTS_ALL")); 4719 4720 for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 4721 Needed_Entry *needed; 4722 const char *name, *path; 4723 bool is_lib; 4724 4725 if (obj->marker) 4726 continue; 4727 if (list_containers && obj->needed != NULL) 4728 rtld_printf("%s:\n", obj->path); 4729 for (needed = obj->needed; needed; needed = needed->next) { 4730 if (needed->obj != NULL) { 4731 if (needed->obj->traced && !list_containers) 4732 continue; 4733 needed->obj->traced = true; 4734 path = needed->obj->path; 4735 } else 4736 path = "not found"; 4737 4738 name = obj->strtab + needed->name; 4739 is_lib = strncmp(name, "lib", 3) == 0; /* XXX - bogus */ 4740 4741 fmt = is_lib ? fmt1 : fmt2; 4742 while ((c = *fmt++) != '\0') { 4743 switch (c) { 4744 default: 4745 rtld_putchar(c); 4746 continue; 4747 case '\\': 4748 switch (c = *fmt) { 4749 case '\0': 4750 continue; 4751 case 'n': 4752 rtld_putchar('\n'); 4753 break; 4754 case 't': 4755 rtld_putchar('\t'); 4756 break; 4757 } 4758 break; 4759 case '%': 4760 switch (c = *fmt) { 4761 case '\0': 4762 continue; 4763 case '%': 4764 default: 4765 rtld_putchar(c); 4766 break; 4767 case 'A': 4768 rtld_putstr(main_local); 4769 break; 4770 case 'a': 4771 rtld_putstr(obj_main->path); 4772 break; 4773 case 'o': 4774 rtld_putstr(name); 4775 break; 4776 #if 0 4777 case 'm': 4778 rtld_printf("%d", sodp->sod_major); 4779 break; 4780 case 'n': 4781 rtld_printf("%d", sodp->sod_minor); 4782 break; 4783 #endif 4784 case 'p': 4785 rtld_putstr(path); 4786 break; 4787 case 'x': 4788 rtld_printf("%p", needed->obj ? needed->obj->mapbase : 4789 0); 4790 break; 4791 } 4792 break; 4793 } 4794 ++fmt; 4795 } 4796 } 4797 } 4798 } 4799 4800 /* 4801 * Unload a dlopened object and its dependencies from memory and from 4802 * our data structures. It is assumed that the DAG rooted in the 4803 * object has already been unreferenced, and that the object has a 4804 * reference count of 0. 4805 */ 4806 static void 4807 unload_object(Obj_Entry *root, RtldLockState *lockstate) 4808 { 4809 Obj_Entry marker, *obj, *next; 4810 4811 assert(root->refcount == 0); 4812 4813 /* 4814 * Pass over the DAG removing unreferenced objects from 4815 * appropriate lists. 4816 */ 4817 unlink_object(root); 4818 4819 /* Unmap all objects that are no longer referenced. */ 4820 for (obj = TAILQ_FIRST(&obj_list); obj != NULL; obj = next) { 4821 next = TAILQ_NEXT(obj, next); 4822 if (obj->marker || obj->refcount != 0) 4823 continue; 4824 LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase, 4825 obj->mapsize, 0, obj->path); 4826 dbg("unloading \"%s\"", obj->path); 4827 /* 4828 * Unlink the object now to prevent new references from 4829 * being acquired while the bind lock is dropped in 4830 * recursive dlclose() invocations. 4831 */ 4832 TAILQ_REMOVE(&obj_list, obj, next); 4833 obj_count--; 4834 4835 if (obj->filtees_loaded) { 4836 if (next != NULL) { 4837 init_marker(&marker); 4838 TAILQ_INSERT_BEFORE(next, &marker, next); 4839 unload_filtees(obj, lockstate); 4840 next = TAILQ_NEXT(&marker, next); 4841 TAILQ_REMOVE(&obj_list, &marker, next); 4842 } else 4843 unload_filtees(obj, lockstate); 4844 } 4845 release_object(obj); 4846 } 4847 } 4848 4849 static void 4850 unlink_object(Obj_Entry *root) 4851 { 4852 Objlist_Entry *elm; 4853 4854 if (root->refcount == 0) { 4855 /* Remove the object from the RTLD_GLOBAL list. */ 4856 objlist_remove(&list_global, root); 4857 4858 /* Remove the object from all objects' DAG lists. */ 4859 STAILQ_FOREACH(elm, &root->dagmembers, link) { 4860 objlist_remove(&elm->obj->dldags, root); 4861 if (elm->obj != root) 4862 unlink_object(elm->obj); 4863 } 4864 } 4865 } 4866 4867 static void 4868 ref_dag(Obj_Entry *root) 4869 { 4870 Objlist_Entry *elm; 4871 4872 assert(root->dag_inited); 4873 STAILQ_FOREACH(elm, &root->dagmembers, link) 4874 elm->obj->refcount++; 4875 } 4876 4877 static void 4878 unref_dag(Obj_Entry *root) 4879 { 4880 Objlist_Entry *elm; 4881 4882 assert(root->dag_inited); 4883 STAILQ_FOREACH(elm, &root->dagmembers, link) 4884 elm->obj->refcount--; 4885 } 4886 4887 /* 4888 * Common code for MD __tls_get_addr(). 4889 */ 4890 static void * 4891 tls_get_addr_slow(Elf_Addr **dtvp, int index, size_t offset, bool locked) 4892 { 4893 Elf_Addr *newdtv, *dtv; 4894 RtldLockState lockstate; 4895 int to_copy; 4896 4897 dtv = *dtvp; 4898 /* Check dtv generation in case new modules have arrived */ 4899 if (dtv[0] != tls_dtv_generation) { 4900 if (!locked) 4901 wlock_acquire(rtld_bind_lock, &lockstate); 4902 newdtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4903 to_copy = dtv[1]; 4904 if (to_copy > tls_max_index) 4905 to_copy = tls_max_index; 4906 memcpy(&newdtv[2], &dtv[2], to_copy * sizeof(Elf_Addr)); 4907 newdtv[0] = tls_dtv_generation; 4908 newdtv[1] = tls_max_index; 4909 free(dtv); 4910 if (!locked) 4911 lock_release(rtld_bind_lock, &lockstate); 4912 dtv = *dtvp = newdtv; 4913 } 4914 4915 /* Dynamically allocate module TLS if necessary */ 4916 if (dtv[index + 1] == 0) { 4917 /* Signal safe, wlock will block out signals. */ 4918 if (!locked) 4919 wlock_acquire(rtld_bind_lock, &lockstate); 4920 if (!dtv[index + 1]) 4921 dtv[index + 1] = (Elf_Addr)allocate_module_tls(index); 4922 if (!locked) 4923 lock_release(rtld_bind_lock, &lockstate); 4924 } 4925 return ((void *)(dtv[index + 1] + offset)); 4926 } 4927 4928 void * 4929 tls_get_addr_common(Elf_Addr **dtvp, int index, size_t offset) 4930 { 4931 Elf_Addr *dtv; 4932 4933 dtv = *dtvp; 4934 /* Check dtv generation in case new modules have arrived */ 4935 if (__predict_true(dtv[0] == tls_dtv_generation && 4936 dtv[index + 1] != 0)) 4937 return ((void *)(dtv[index + 1] + offset)); 4938 return (tls_get_addr_slow(dtvp, index, offset, false)); 4939 } 4940 4941 #if defined(__aarch64__) || defined(__arm__) || defined(__mips__) || \ 4942 defined(__powerpc__) || defined(__riscv) 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 5074 5075 #if defined(__i386__) || defined(__amd64__) 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 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 /* 5230 * If we have already fixed the size of the static TLS block, we 5231 * must stay within that size. When allocating the static TLS, we 5232 * leave a small amount of space spare to be used for dynamically 5233 * loading modules which use static TLS. 5234 */ 5235 if (tls_static_space != 0) { 5236 if (calculate_tls_end(off, obj->tlssize) > tls_static_space) 5237 return false; 5238 } else if (obj->tlsalign > tls_static_max_align) { 5239 tls_static_max_align = obj->tlsalign; 5240 } 5241 5242 tls_last_offset = obj->tlsoffset = off; 5243 tls_last_size = obj->tlssize; 5244 obj->tls_done = true; 5245 5246 return true; 5247 } 5248 5249 void 5250 free_tls_offset(Obj_Entry *obj) 5251 { 5252 5253 /* 5254 * If we were the last thing to allocate out of the static TLS 5255 * block, we give our space back to the 'allocator'. This is a 5256 * simplistic workaround to allow libGL.so.1 to be loaded and 5257 * unloaded multiple times. 5258 */ 5259 if (calculate_tls_end(obj->tlsoffset, obj->tlssize) 5260 == calculate_tls_end(tls_last_offset, tls_last_size)) { 5261 tls_last_offset -= obj->tlssize; 5262 tls_last_size = 0; 5263 } 5264 } 5265 5266 void * 5267 _rtld_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign) 5268 { 5269 void *ret; 5270 RtldLockState lockstate; 5271 5272 wlock_acquire(rtld_bind_lock, &lockstate); 5273 ret = allocate_tls(globallist_curr(TAILQ_FIRST(&obj_list)), oldtls, 5274 tcbsize, tcbalign); 5275 lock_release(rtld_bind_lock, &lockstate); 5276 return (ret); 5277 } 5278 5279 void 5280 _rtld_free_tls(void *tcb, size_t tcbsize, size_t tcbalign) 5281 { 5282 RtldLockState lockstate; 5283 5284 wlock_acquire(rtld_bind_lock, &lockstate); 5285 free_tls(tcb, tcbsize, tcbalign); 5286 lock_release(rtld_bind_lock, &lockstate); 5287 } 5288 5289 static void 5290 object_add_name(Obj_Entry *obj, const char *name) 5291 { 5292 Name_Entry *entry; 5293 size_t len; 5294 5295 len = strlen(name); 5296 entry = malloc(sizeof(Name_Entry) + len); 5297 5298 if (entry != NULL) { 5299 strcpy(entry->name, name); 5300 STAILQ_INSERT_TAIL(&obj->names, entry, link); 5301 } 5302 } 5303 5304 static int 5305 object_match_name(const Obj_Entry *obj, const char *name) 5306 { 5307 Name_Entry *entry; 5308 5309 STAILQ_FOREACH(entry, &obj->names, link) { 5310 if (strcmp(name, entry->name) == 0) 5311 return (1); 5312 } 5313 return (0); 5314 } 5315 5316 static Obj_Entry * 5317 locate_dependency(const Obj_Entry *obj, const char *name) 5318 { 5319 const Objlist_Entry *entry; 5320 const Needed_Entry *needed; 5321 5322 STAILQ_FOREACH(entry, &list_main, link) { 5323 if (object_match_name(entry->obj, name)) 5324 return entry->obj; 5325 } 5326 5327 for (needed = obj->needed; needed != NULL; needed = needed->next) { 5328 if (strcmp(obj->strtab + needed->name, name) == 0 || 5329 (needed->obj != NULL && object_match_name(needed->obj, name))) { 5330 /* 5331 * If there is DT_NEEDED for the name we are looking for, 5332 * we are all set. Note that object might not be found if 5333 * dependency was not loaded yet, so the function can 5334 * return NULL here. This is expected and handled 5335 * properly by the caller. 5336 */ 5337 return (needed->obj); 5338 } 5339 } 5340 _rtld_error("%s: Unexpected inconsistency: dependency %s not found", 5341 obj->path, name); 5342 rtld_die(); 5343 } 5344 5345 static int 5346 check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj, 5347 const Elf_Vernaux *vna) 5348 { 5349 const Elf_Verdef *vd; 5350 const char *vername; 5351 5352 vername = refobj->strtab + vna->vna_name; 5353 vd = depobj->verdef; 5354 if (vd == NULL) { 5355 _rtld_error("%s: version %s required by %s not defined", 5356 depobj->path, vername, refobj->path); 5357 return (-1); 5358 } 5359 for (;;) { 5360 if (vd->vd_version != VER_DEF_CURRENT) { 5361 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 5362 depobj->path, vd->vd_version); 5363 return (-1); 5364 } 5365 if (vna->vna_hash == vd->vd_hash) { 5366 const Elf_Verdaux *aux = (const Elf_Verdaux *) 5367 ((const char *)vd + vd->vd_aux); 5368 if (strcmp(vername, depobj->strtab + aux->vda_name) == 0) 5369 return (0); 5370 } 5371 if (vd->vd_next == 0) 5372 break; 5373 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 5374 } 5375 if (vna->vna_flags & VER_FLG_WEAK) 5376 return (0); 5377 _rtld_error("%s: version %s required by %s not found", 5378 depobj->path, vername, refobj->path); 5379 return (-1); 5380 } 5381 5382 static int 5383 rtld_verify_object_versions(Obj_Entry *obj) 5384 { 5385 const Elf_Verneed *vn; 5386 const Elf_Verdef *vd; 5387 const Elf_Verdaux *vda; 5388 const Elf_Vernaux *vna; 5389 const Obj_Entry *depobj; 5390 int maxvernum, vernum; 5391 5392 if (obj->ver_checked) 5393 return (0); 5394 obj->ver_checked = true; 5395 5396 maxvernum = 0; 5397 /* 5398 * Walk over defined and required version records and figure out 5399 * max index used by any of them. Do very basic sanity checking 5400 * while there. 5401 */ 5402 vn = obj->verneed; 5403 while (vn != NULL) { 5404 if (vn->vn_version != VER_NEED_CURRENT) { 5405 _rtld_error("%s: Unsupported version %d of Elf_Verneed entry", 5406 obj->path, vn->vn_version); 5407 return (-1); 5408 } 5409 vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux); 5410 for (;;) { 5411 vernum = VER_NEED_IDX(vna->vna_other); 5412 if (vernum > maxvernum) 5413 maxvernum = vernum; 5414 if (vna->vna_next == 0) 5415 break; 5416 vna = (const Elf_Vernaux *)((const char *)vna + vna->vna_next); 5417 } 5418 if (vn->vn_next == 0) 5419 break; 5420 vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next); 5421 } 5422 5423 vd = obj->verdef; 5424 while (vd != NULL) { 5425 if (vd->vd_version != VER_DEF_CURRENT) { 5426 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 5427 obj->path, vd->vd_version); 5428 return (-1); 5429 } 5430 vernum = VER_DEF_IDX(vd->vd_ndx); 5431 if (vernum > maxvernum) 5432 maxvernum = vernum; 5433 if (vd->vd_next == 0) 5434 break; 5435 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 5436 } 5437 5438 if (maxvernum == 0) 5439 return (0); 5440 5441 /* 5442 * Store version information in array indexable by version index. 5443 * Verify that object version requirements are satisfied along the 5444 * way. 5445 */ 5446 obj->vernum = maxvernum + 1; 5447 obj->vertab = xcalloc(obj->vernum, sizeof(Ver_Entry)); 5448 5449 vd = obj->verdef; 5450 while (vd != NULL) { 5451 if ((vd->vd_flags & VER_FLG_BASE) == 0) { 5452 vernum = VER_DEF_IDX(vd->vd_ndx); 5453 assert(vernum <= maxvernum); 5454 vda = (const Elf_Verdaux *)((const char *)vd + vd->vd_aux); 5455 obj->vertab[vernum].hash = vd->vd_hash; 5456 obj->vertab[vernum].name = obj->strtab + vda->vda_name; 5457 obj->vertab[vernum].file = NULL; 5458 obj->vertab[vernum].flags = 0; 5459 } 5460 if (vd->vd_next == 0) 5461 break; 5462 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 5463 } 5464 5465 vn = obj->verneed; 5466 while (vn != NULL) { 5467 depobj = locate_dependency(obj, obj->strtab + vn->vn_file); 5468 if (depobj == NULL) 5469 return (-1); 5470 vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux); 5471 for (;;) { 5472 if (check_object_provided_version(obj, depobj, vna)) 5473 return (-1); 5474 vernum = VER_NEED_IDX(vna->vna_other); 5475 assert(vernum <= maxvernum); 5476 obj->vertab[vernum].hash = vna->vna_hash; 5477 obj->vertab[vernum].name = obj->strtab + vna->vna_name; 5478 obj->vertab[vernum].file = obj->strtab + vn->vn_file; 5479 obj->vertab[vernum].flags = (vna->vna_other & VER_NEED_HIDDEN) ? 5480 VER_INFO_HIDDEN : 0; 5481 if (vna->vna_next == 0) 5482 break; 5483 vna = (const Elf_Vernaux *)((const char *)vna + vna->vna_next); 5484 } 5485 if (vn->vn_next == 0) 5486 break; 5487 vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next); 5488 } 5489 return 0; 5490 } 5491 5492 static int 5493 rtld_verify_versions(const Objlist *objlist) 5494 { 5495 Objlist_Entry *entry; 5496 int rc; 5497 5498 rc = 0; 5499 STAILQ_FOREACH(entry, objlist, link) { 5500 /* 5501 * Skip dummy objects or objects that have their version requirements 5502 * already checked. 5503 */ 5504 if (entry->obj->strtab == NULL || entry->obj->vertab != NULL) 5505 continue; 5506 if (rtld_verify_object_versions(entry->obj) == -1) { 5507 rc = -1; 5508 if (ld_tracing == NULL) 5509 break; 5510 } 5511 } 5512 if (rc == 0 || ld_tracing != NULL) 5513 rc = rtld_verify_object_versions(&obj_rtld); 5514 return rc; 5515 } 5516 5517 const Ver_Entry * 5518 fetch_ventry(const Obj_Entry *obj, unsigned long symnum) 5519 { 5520 Elf_Versym vernum; 5521 5522 if (obj->vertab) { 5523 vernum = VER_NDX(obj->versyms[symnum]); 5524 if (vernum >= obj->vernum) { 5525 _rtld_error("%s: symbol %s has wrong verneed value %d", 5526 obj->path, obj->strtab + symnum, vernum); 5527 } else if (obj->vertab[vernum].hash != 0) { 5528 return &obj->vertab[vernum]; 5529 } 5530 } 5531 return NULL; 5532 } 5533 5534 int 5535 _rtld_get_stack_prot(void) 5536 { 5537 5538 return (stack_prot); 5539 } 5540 5541 int 5542 _rtld_is_dlopened(void *arg) 5543 { 5544 Obj_Entry *obj; 5545 RtldLockState lockstate; 5546 int res; 5547 5548 rlock_acquire(rtld_bind_lock, &lockstate); 5549 obj = dlcheck(arg); 5550 if (obj == NULL) 5551 obj = obj_from_addr(arg); 5552 if (obj == NULL) { 5553 _rtld_error("No shared object contains address"); 5554 lock_release(rtld_bind_lock, &lockstate); 5555 return (-1); 5556 } 5557 res = obj->dlopened ? 1 : 0; 5558 lock_release(rtld_bind_lock, &lockstate); 5559 return (res); 5560 } 5561 5562 static int 5563 obj_remap_relro(Obj_Entry *obj, int prot) 5564 { 5565 5566 if (obj->relro_size > 0 && mprotect(obj->relro_page, obj->relro_size, 5567 prot) == -1) { 5568 _rtld_error("%s: Cannot set relro protection to %#x: %s", 5569 obj->path, prot, rtld_strerror(errno)); 5570 return (-1); 5571 } 5572 return (0); 5573 } 5574 5575 static int 5576 obj_disable_relro(Obj_Entry *obj) 5577 { 5578 5579 return (obj_remap_relro(obj, PROT_READ | PROT_WRITE)); 5580 } 5581 5582 static int 5583 obj_enforce_relro(Obj_Entry *obj) 5584 { 5585 5586 return (obj_remap_relro(obj, PROT_READ)); 5587 } 5588 5589 static void 5590 map_stacks_exec(RtldLockState *lockstate) 5591 { 5592 void (*thr_map_stacks_exec)(void); 5593 5594 if ((max_stack_flags & PF_X) == 0 || (stack_prot & PROT_EXEC) != 0) 5595 return; 5596 thr_map_stacks_exec = (void (*)(void))(uintptr_t) 5597 get_program_var_addr("__pthread_map_stacks_exec", lockstate); 5598 if (thr_map_stacks_exec != NULL) { 5599 stack_prot |= PROT_EXEC; 5600 thr_map_stacks_exec(); 5601 } 5602 } 5603 5604 static void 5605 distribute_static_tls(Objlist *list, RtldLockState *lockstate) 5606 { 5607 Objlist_Entry *elm; 5608 Obj_Entry *obj; 5609 void (*distrib)(size_t, void *, size_t, size_t); 5610 5611 distrib = (void (*)(size_t, void *, size_t, size_t))(uintptr_t) 5612 get_program_var_addr("__pthread_distribute_static_tls", lockstate); 5613 if (distrib == NULL) 5614 return; 5615 STAILQ_FOREACH(elm, list, link) { 5616 obj = elm->obj; 5617 if (obj->marker || !obj->tls_done || obj->static_tls_copied) 5618 continue; 5619 distrib(obj->tlsoffset, obj->tlsinit, obj->tlsinitsize, 5620 obj->tlssize); 5621 obj->static_tls_copied = true; 5622 } 5623 } 5624 5625 void 5626 symlook_init(SymLook *dst, const char *name) 5627 { 5628 5629 bzero(dst, sizeof(*dst)); 5630 dst->name = name; 5631 dst->hash = elf_hash(name); 5632 dst->hash_gnu = gnu_hash(name); 5633 } 5634 5635 static void 5636 symlook_init_from_req(SymLook *dst, const SymLook *src) 5637 { 5638 5639 dst->name = src->name; 5640 dst->hash = src->hash; 5641 dst->hash_gnu = src->hash_gnu; 5642 dst->ventry = src->ventry; 5643 dst->flags = src->flags; 5644 dst->defobj_out = NULL; 5645 dst->sym_out = NULL; 5646 dst->lockstate = src->lockstate; 5647 } 5648 5649 static int 5650 open_binary_fd(const char *argv0, bool search_in_path, 5651 const char **binpath_res) 5652 { 5653 char *binpath, *pathenv, *pe, *res1; 5654 const char *res; 5655 int fd; 5656 5657 binpath = NULL; 5658 res = NULL; 5659 if (search_in_path && strchr(argv0, '/') == NULL) { 5660 binpath = xmalloc(PATH_MAX); 5661 pathenv = getenv("PATH"); 5662 if (pathenv == NULL) { 5663 _rtld_error("-p and no PATH environment variable"); 5664 rtld_die(); 5665 } 5666 pathenv = strdup(pathenv); 5667 if (pathenv == NULL) { 5668 _rtld_error("Cannot allocate memory"); 5669 rtld_die(); 5670 } 5671 fd = -1; 5672 errno = ENOENT; 5673 while ((pe = strsep(&pathenv, ":")) != NULL) { 5674 if (strlcpy(binpath, pe, PATH_MAX) >= PATH_MAX) 5675 continue; 5676 if (binpath[0] != '\0' && 5677 strlcat(binpath, "/", PATH_MAX) >= PATH_MAX) 5678 continue; 5679 if (strlcat(binpath, argv0, PATH_MAX) >= PATH_MAX) 5680 continue; 5681 fd = open(binpath, O_RDONLY | O_CLOEXEC | O_VERIFY); 5682 if (fd != -1 || errno != ENOENT) { 5683 res = binpath; 5684 break; 5685 } 5686 } 5687 free(pathenv); 5688 } else { 5689 fd = open(argv0, O_RDONLY | O_CLOEXEC | O_VERIFY); 5690 res = argv0; 5691 } 5692 5693 if (fd == -1) { 5694 _rtld_error("Cannot open %s: %s", argv0, rtld_strerror(errno)); 5695 rtld_die(); 5696 } 5697 if (res != NULL && res[0] != '/') { 5698 res1 = xmalloc(PATH_MAX); 5699 if (realpath(res, res1) != NULL) { 5700 if (res != argv0) 5701 free(__DECONST(char *, res)); 5702 res = res1; 5703 } else { 5704 free(res1); 5705 } 5706 } 5707 *binpath_res = res; 5708 return (fd); 5709 } 5710 5711 /* 5712 * Parse a set of command-line arguments. 5713 */ 5714 static int 5715 parse_args(char* argv[], int argc, bool *use_pathp, int *fdp, 5716 const char **argv0) 5717 { 5718 const char *arg; 5719 char machine[64]; 5720 size_t sz; 5721 int arglen, fd, i, j, mib[2]; 5722 char opt; 5723 bool seen_b, seen_f; 5724 5725 dbg("Parsing command-line arguments"); 5726 *use_pathp = false; 5727 *fdp = -1; 5728 seen_b = seen_f = false; 5729 5730 for (i = 1; i < argc; i++ ) { 5731 arg = argv[i]; 5732 dbg("argv[%d]: '%s'", i, arg); 5733 5734 /* 5735 * rtld arguments end with an explicit "--" or with the first 5736 * non-prefixed argument. 5737 */ 5738 if (strcmp(arg, "--") == 0) { 5739 i++; 5740 break; 5741 } 5742 if (arg[0] != '-') 5743 break; 5744 5745 /* 5746 * All other arguments are single-character options that can 5747 * be combined, so we need to search through `arg` for them. 5748 */ 5749 arglen = strlen(arg); 5750 for (j = 1; j < arglen; j++) { 5751 opt = arg[j]; 5752 if (opt == 'h') { 5753 print_usage(argv[0]); 5754 _exit(0); 5755 } else if (opt == 'b') { 5756 if (seen_f) { 5757 _rtld_error("Both -b and -f specified"); 5758 rtld_die(); 5759 } 5760 i++; 5761 *argv0 = argv[i]; 5762 seen_b = true; 5763 break; 5764 } else if (opt == 'f') { 5765 if (seen_b) { 5766 _rtld_error("Both -b and -f specified"); 5767 rtld_die(); 5768 } 5769 5770 /* 5771 * -f XX can be used to specify a 5772 * descriptor for the binary named at 5773 * the command line (i.e., the later 5774 * argument will specify the process 5775 * name but the descriptor is what 5776 * will actually be executed). 5777 * 5778 * -f must be the last option in, e.g., -abcf. 5779 */ 5780 if (j != arglen - 1) { 5781 _rtld_error("Invalid options: %s", arg); 5782 rtld_die(); 5783 } 5784 i++; 5785 fd = parse_integer(argv[i]); 5786 if (fd == -1) { 5787 _rtld_error( 5788 "Invalid file descriptor: '%s'", 5789 argv[i]); 5790 rtld_die(); 5791 } 5792 *fdp = fd; 5793 seen_f = true; 5794 break; 5795 } else if (opt == 'p') { 5796 *use_pathp = true; 5797 } else if (opt == 'u') { 5798 trust = false; 5799 } else if (opt == 'v') { 5800 machine[0] = '\0'; 5801 mib[0] = CTL_HW; 5802 mib[1] = HW_MACHINE; 5803 sz = sizeof(machine); 5804 sysctl(mib, nitems(mib), machine, &sz, NULL, 0); 5805 rtld_printf( 5806 "FreeBSD ld-elf.so.1 %s\n" 5807 "FreeBSD_version %d\n" 5808 "Default lib path %s\n" 5809 "Env prefix %s\n" 5810 "Hint file %s\n" 5811 "libmap file %s\n", 5812 machine, 5813 __FreeBSD_version, ld_standard_library_path, 5814 ld_env_prefix, ld_elf_hints_default, 5815 ld_path_libmap_conf); 5816 _exit(0); 5817 } else { 5818 _rtld_error("Invalid argument: '%s'", arg); 5819 print_usage(argv[0]); 5820 rtld_die(); 5821 } 5822 } 5823 } 5824 5825 if (!seen_b) 5826 *argv0 = argv[i]; 5827 return (i); 5828 } 5829 5830 /* 5831 * Parse a file descriptor number without pulling in more of libc (e.g. atoi). 5832 */ 5833 static int 5834 parse_integer(const char *str) 5835 { 5836 static const int RADIX = 10; /* XXXJA: possibly support hex? */ 5837 const char *orig; 5838 int n; 5839 char c; 5840 5841 orig = str; 5842 n = 0; 5843 for (c = *str; c != '\0'; c = *++str) { 5844 if (c < '0' || c > '9') 5845 return (-1); 5846 5847 n *= RADIX; 5848 n += c - '0'; 5849 } 5850 5851 /* Make sure we actually parsed something. */ 5852 if (str == orig) 5853 return (-1); 5854 return (n); 5855 } 5856 5857 static void 5858 print_usage(const char *argv0) 5859 { 5860 5861 rtld_printf( 5862 "Usage: %s [-h] [-b <exe>] [-f <FD>] [-p] [--] <binary> [<args>]\n" 5863 "\n" 5864 "Options:\n" 5865 " -h Display this help message\n" 5866 " -b <exe> Execute <exe> instead of <binary>, arg0 is <binary>\n" 5867 " -f <FD> Execute <FD> instead of searching for <binary>\n" 5868 " -p Search in PATH for named binary\n" 5869 " -u Ignore LD_ environment variables\n" 5870 " -v Display identification information\n" 5871 " -- End of RTLD options\n" 5872 " <binary> Name of process to execute\n" 5873 " <args> Arguments to the executed process\n", argv0); 5874 } 5875 5876 /* 5877 * Overrides for libc_pic-provided functions. 5878 */ 5879 5880 int 5881 __getosreldate(void) 5882 { 5883 size_t len; 5884 int oid[2]; 5885 int error, osrel; 5886 5887 if (osreldate != 0) 5888 return (osreldate); 5889 5890 oid[0] = CTL_KERN; 5891 oid[1] = KERN_OSRELDATE; 5892 osrel = 0; 5893 len = sizeof(osrel); 5894 error = sysctl(oid, 2, &osrel, &len, NULL, 0); 5895 if (error == 0 && osrel > 0 && len == sizeof(osrel)) 5896 osreldate = osrel; 5897 return (osreldate); 5898 } 5899 const char * 5900 rtld_strerror(int errnum) 5901 { 5902 5903 if (errnum < 0 || errnum >= sys_nerr) 5904 return ("Unknown error"); 5905 return (sys_errlist[errnum]); 5906 } 5907 5908 /* malloc */ 5909 void * 5910 malloc(size_t nbytes) 5911 { 5912 5913 return (__crt_malloc(nbytes)); 5914 } 5915 5916 void * 5917 calloc(size_t num, size_t size) 5918 { 5919 5920 return (__crt_calloc(num, size)); 5921 } 5922 5923 void 5924 free(void *cp) 5925 { 5926 5927 __crt_free(cp); 5928 } 5929 5930 void * 5931 realloc(void *cp, size_t nbytes) 5932 { 5933 5934 return (__crt_realloc(cp, nbytes)); 5935 } 5936 5937 extern int _rtld_version__FreeBSD_version __exported; 5938 int _rtld_version__FreeBSD_version = __FreeBSD_version; 5939 5940 extern char _rtld_version_laddr_offset __exported; 5941 char _rtld_version_laddr_offset; 5942 5943 extern char _rtld_version_dlpi_tls_data __exported; 5944 char _rtld_version_dlpi_tls_data; 5945