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 "rtld_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 dump_auxv(Elf_Auxinfo **aux_info); 108 static void errmsg_restore(struct dlerror_save *); 109 static struct dlerror_save *errmsg_save(void); 110 static void *fill_search_info(const char *, size_t, void *); 111 static char *find_library(const char *, const Obj_Entry *, int *); 112 static const char *gethints(bool); 113 static void hold_object(Obj_Entry *); 114 static void unhold_object(Obj_Entry *); 115 static void init_dag(Obj_Entry *); 116 static void init_marker(Obj_Entry *); 117 static void init_pagesizes(Elf_Auxinfo **aux_info); 118 static void init_rtld(caddr_t, Elf_Auxinfo **); 119 static void initlist_add_neededs(Needed_Entry *, Objlist *); 120 static void initlist_add_objects(Obj_Entry *, Obj_Entry *, Objlist *); 121 static int initlist_objects_ifunc(Objlist *, bool, int, RtldLockState *); 122 static void linkmap_add(Obj_Entry *); 123 static void linkmap_delete(Obj_Entry *); 124 static void load_filtees(Obj_Entry *, int flags, RtldLockState *); 125 static void unload_filtees(Obj_Entry *, RtldLockState *); 126 static int load_needed_objects(Obj_Entry *, int); 127 static int load_preload_objects(const char *, bool); 128 static int load_kpreload(const void *addr); 129 static Obj_Entry *load_object(const char *, int fd, const Obj_Entry *, int); 130 static void map_stacks_exec(RtldLockState *); 131 static int obj_disable_relro(Obj_Entry *); 132 static int obj_enforce_relro(Obj_Entry *); 133 static void objlist_call_fini(Objlist *, Obj_Entry *, RtldLockState *); 134 static void objlist_call_init(Objlist *, RtldLockState *); 135 static void objlist_clear(Objlist *); 136 static Objlist_Entry *objlist_find(Objlist *, const Obj_Entry *); 137 static void objlist_init(Objlist *); 138 static void objlist_push_head(Objlist *, Obj_Entry *); 139 static void objlist_push_tail(Objlist *, Obj_Entry *); 140 static void objlist_put_after(Objlist *, Obj_Entry *, Obj_Entry *); 141 static void objlist_remove(Objlist *, Obj_Entry *); 142 static int open_binary_fd(const char *argv0, bool search_in_path, 143 const char **binpath_res); 144 static int parse_args(char* argv[], int argc, bool *use_pathp, int *fdp, 145 const char **argv0, bool *dir_ignore); 146 static int parse_integer(const char *); 147 static void *path_enumerate(const char *, path_enum_proc, const char *, void *); 148 static void print_usage(const char *argv0); 149 static void release_object(Obj_Entry *); 150 static int relocate_object_dag(Obj_Entry *root, bool bind_now, 151 Obj_Entry *rtldobj, int flags, RtldLockState *lockstate); 152 static int relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, 153 int flags, RtldLockState *lockstate); 154 static int relocate_objects(Obj_Entry *, bool, Obj_Entry *, int, 155 RtldLockState *); 156 static int resolve_object_ifunc(Obj_Entry *, bool, int, RtldLockState *); 157 static int rtld_dirname(const char *, char *); 158 static int rtld_dirname_abs(const char *, char *); 159 static void *rtld_dlopen(const char *name, int fd, int mode); 160 static void rtld_exit(void); 161 static void rtld_nop_exit(void); 162 static char *search_library_path(const char *, const char *, const char *, 163 int *); 164 static char *search_library_pathfds(const char *, const char *, int *); 165 static const void **get_program_var_addr(const char *, RtldLockState *); 166 static void set_program_var(const char *, const void *); 167 static int symlook_default(SymLook *, const Obj_Entry *refobj); 168 static int symlook_global(SymLook *, DoneList *); 169 static void symlook_init_from_req(SymLook *, const SymLook *); 170 static int symlook_list(SymLook *, const Objlist *, DoneList *); 171 static int symlook_needed(SymLook *, const Needed_Entry *, DoneList *); 172 static int symlook_obj1_sysv(SymLook *, const Obj_Entry *); 173 static int symlook_obj1_gnu(SymLook *, const Obj_Entry *); 174 static void *tls_get_addr_slow(Elf_Addr **, int, size_t, bool) __noinline; 175 static void trace_loaded_objects(Obj_Entry *, bool); 176 static void unlink_object(Obj_Entry *); 177 static void unload_object(Obj_Entry *, RtldLockState *lockstate); 178 static void unref_dag(Obj_Entry *); 179 static void ref_dag(Obj_Entry *); 180 static char *origin_subst_one(Obj_Entry *, char *, const char *, 181 const char *, bool); 182 static char *origin_subst(Obj_Entry *, const char *); 183 static bool obj_resolve_origin(Obj_Entry *obj); 184 static void preinit_main(void); 185 static int rtld_verify_versions(const Objlist *); 186 static int rtld_verify_object_versions(Obj_Entry *); 187 static void object_add_name(Obj_Entry *, const char *); 188 static int object_match_name(const Obj_Entry *, const char *); 189 static void ld_utrace_log(int, void *, void *, size_t, int, const char *); 190 static void rtld_fill_dl_phdr_info(const Obj_Entry *obj, 191 struct dl_phdr_info *phdr_info); 192 static uint32_t gnu_hash(const char *); 193 static bool matched_symbol(SymLook *, const Obj_Entry *, Sym_Match_Result *, 194 const unsigned long); 195 196 void r_debug_state(struct r_debug *, struct link_map *) __noinline __exported; 197 void _r_debug_postinit(struct link_map *) __noinline __exported; 198 199 int __sys_openat(int, const char *, int, ...); 200 201 /* 202 * Data declarations. 203 */ 204 struct r_debug r_debug __exported; /* for GDB; */ 205 static bool libmap_disable; /* Disable libmap */ 206 static bool ld_loadfltr; /* Immediate filters processing */ 207 static const char *libmap_override;/* Maps to use in addition to libmap.conf */ 208 static bool trust; /* False for setuid and setgid programs */ 209 static bool dangerous_ld_env; /* True if environment variables have been 210 used to affect the libraries loaded */ 211 bool ld_bind_not; /* Disable PLT update */ 212 static const char *ld_bind_now; /* Environment variable for immediate binding */ 213 static const char *ld_debug; /* Environment variable for debugging */ 214 static bool ld_dynamic_weak = true; /* True if non-weak definition overrides 215 weak definition */ 216 static const char *ld_library_path;/* Environment variable for search path */ 217 static const char *ld_library_dirs;/* Environment variable for library descriptors */ 218 static const char *ld_preload; /* Environment variable for libraries to 219 load first */ 220 static const char *ld_preload_fds;/* Environment variable for libraries represented by 221 descriptors */ 222 static const char *ld_elf_hints_path; /* Environment variable for alternative hints path */ 223 static const char *ld_tracing; /* Called from ldd to print libs */ 224 static const char *ld_utrace; /* Use utrace() to log events. */ 225 static struct obj_entry_q obj_list; /* Queue of all loaded objects */ 226 static Obj_Entry *obj_main; /* The main program shared object */ 227 static Obj_Entry obj_rtld; /* The dynamic linker shared object */ 228 static unsigned int obj_count; /* Number of objects in obj_list */ 229 static unsigned int obj_loads; /* Number of loads of objects (gen count) */ 230 231 static Objlist list_global = /* Objects dlopened with RTLD_GLOBAL */ 232 STAILQ_HEAD_INITIALIZER(list_global); 233 static Objlist list_main = /* Objects loaded at program startup */ 234 STAILQ_HEAD_INITIALIZER(list_main); 235 static Objlist list_fini = /* Objects needing fini() calls */ 236 STAILQ_HEAD_INITIALIZER(list_fini); 237 238 Elf_Sym sym_zero; /* For resolving undefined weak refs. */ 239 240 #define GDB_STATE(s,m) r_debug.r_state = s; r_debug_state(&r_debug,m); 241 242 extern Elf_Dyn _DYNAMIC; 243 #pragma weak _DYNAMIC 244 245 int dlclose(void *) __exported; 246 char *dlerror(void) __exported; 247 void *dlopen(const char *, int) __exported; 248 void *fdlopen(int, int) __exported; 249 void *dlsym(void *, const char *) __exported; 250 dlfunc_t dlfunc(void *, const char *) __exported; 251 void *dlvsym(void *, const char *, const char *) __exported; 252 int dladdr(const void *, Dl_info *) __exported; 253 void dllockinit(void *, void *(*)(void *), void (*)(void *), void (*)(void *), 254 void (*)(void *), void (*)(void *), void (*)(void *)) __exported; 255 int dlinfo(void *, int , void *) __exported; 256 int dl_iterate_phdr(__dl_iterate_hdr_callback, void *) __exported; 257 int _rtld_addr_phdr(const void *, struct dl_phdr_info *) __exported; 258 int _rtld_get_stack_prot(void) __exported; 259 int _rtld_is_dlopened(void *) __exported; 260 void _rtld_error(const char *, ...) __exported; 261 262 /* Only here to fix -Wmissing-prototypes warnings */ 263 int __getosreldate(void); 264 func_ptr_type _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp); 265 Elf_Addr _rtld_bind(Obj_Entry *obj, Elf_Size reloff); 266 267 int npagesizes; 268 static int osreldate; 269 size_t *pagesizes; 270 size_t page_size; 271 272 static int stack_prot = PROT_READ | PROT_WRITE | RTLD_DEFAULT_STACK_EXEC; 273 static int max_stack_flags; 274 275 /* 276 * Global declarations normally provided by crt1. The dynamic linker is 277 * not built with crt1, so we have to provide them ourselves. 278 */ 279 char *__progname; 280 char **environ; 281 282 /* 283 * Used to pass argc, argv to init functions. 284 */ 285 int main_argc; 286 char **main_argv; 287 288 /* 289 * Globals to control TLS allocation. 290 */ 291 size_t tls_last_offset; /* Static TLS offset of last module */ 292 size_t tls_last_size; /* Static TLS size of last module */ 293 size_t tls_static_space; /* Static TLS space allocated */ 294 static size_t tls_static_max_align; 295 Elf_Addr tls_dtv_generation = 1; /* Used to detect when dtv size changes */ 296 int tls_max_index = 1; /* Largest module index allocated */ 297 298 static bool ld_library_path_rpath = false; 299 bool ld_fast_sigblock = false; 300 301 /* 302 * Globals for path names, and such 303 */ 304 const char *ld_elf_hints_default = _PATH_ELF_HINTS; 305 const char *ld_path_libmap_conf = _PATH_LIBMAP_CONF; 306 const char *ld_path_rtld = _PATH_RTLD; 307 const char *ld_standard_library_path = STANDARD_LIBRARY_PATH; 308 const char *ld_env_prefix = LD_; 309 310 static void (*rtld_exit_ptr)(void); 311 312 /* 313 * Fill in a DoneList with an allocation large enough to hold all of 314 * the currently-loaded objects. Keep this as a macro since it calls 315 * alloca and we want that to occur within the scope of the caller. 316 */ 317 #define donelist_init(dlp) \ 318 ((dlp)->objs = alloca(obj_count * sizeof (dlp)->objs[0]), \ 319 assert((dlp)->objs != NULL), \ 320 (dlp)->num_alloc = obj_count, \ 321 (dlp)->num_used = 0) 322 323 #define LD_UTRACE(e, h, mb, ms, r, n) do { \ 324 if (ld_utrace != NULL) \ 325 ld_utrace_log(e, h, mb, ms, r, n); \ 326 } while (0) 327 328 static void 329 ld_utrace_log(int event, void *handle, void *mapbase, size_t mapsize, 330 int refcnt, const char *name) 331 { 332 struct utrace_rtld ut; 333 static const char rtld_utrace_sig[RTLD_UTRACE_SIG_SZ] = RTLD_UTRACE_SIG; 334 335 memcpy(ut.sig, rtld_utrace_sig, sizeof(ut.sig)); 336 ut.event = event; 337 ut.handle = handle; 338 ut.mapbase = mapbase; 339 ut.mapsize = mapsize; 340 ut.refcnt = refcnt; 341 bzero(ut.name, sizeof(ut.name)); 342 if (name) 343 strlcpy(ut.name, name, sizeof(ut.name)); 344 utrace(&ut, sizeof(ut)); 345 } 346 347 enum { 348 LD_BIND_NOW = 0, 349 LD_PRELOAD, 350 LD_LIBMAP, 351 LD_LIBRARY_PATH, 352 LD_LIBRARY_PATH_FDS, 353 LD_LIBMAP_DISABLE, 354 LD_BIND_NOT, 355 LD_DEBUG, 356 LD_ELF_HINTS_PATH, 357 LD_LOADFLTR, 358 LD_LIBRARY_PATH_RPATH, 359 LD_PRELOAD_FDS, 360 LD_DYNAMIC_WEAK, 361 LD_TRACE_LOADED_OBJECTS, 362 LD_UTRACE, 363 LD_DUMP_REL_PRE, 364 LD_DUMP_REL_POST, 365 LD_TRACE_LOADED_OBJECTS_PROGNAME, 366 LD_TRACE_LOADED_OBJECTS_FMT1, 367 LD_TRACE_LOADED_OBJECTS_FMT2, 368 LD_TRACE_LOADED_OBJECTS_ALL, 369 LD_SHOW_AUXV, 370 }; 371 372 struct ld_env_var_desc { 373 const char * const n; 374 const char *val; 375 const bool unsecure; 376 }; 377 #define LD_ENV_DESC(var, unsec) \ 378 [LD_##var] = { .n = #var, .unsecure = unsec } 379 380 static struct ld_env_var_desc ld_env_vars[] = { 381 LD_ENV_DESC(BIND_NOW, false), 382 LD_ENV_DESC(PRELOAD, true), 383 LD_ENV_DESC(LIBMAP, true), 384 LD_ENV_DESC(LIBRARY_PATH, true), 385 LD_ENV_DESC(LIBRARY_PATH_FDS, true), 386 LD_ENV_DESC(LIBMAP_DISABLE, true), 387 LD_ENV_DESC(BIND_NOT, true), 388 LD_ENV_DESC(DEBUG, true), 389 LD_ENV_DESC(ELF_HINTS_PATH, true), 390 LD_ENV_DESC(LOADFLTR, true), 391 LD_ENV_DESC(LIBRARY_PATH_RPATH, true), 392 LD_ENV_DESC(PRELOAD_FDS, true), 393 LD_ENV_DESC(DYNAMIC_WEAK, true), 394 LD_ENV_DESC(TRACE_LOADED_OBJECTS, false), 395 LD_ENV_DESC(UTRACE, false), 396 LD_ENV_DESC(DUMP_REL_PRE, false), 397 LD_ENV_DESC(DUMP_REL_POST, false), 398 LD_ENV_DESC(TRACE_LOADED_OBJECTS_PROGNAME, false), 399 LD_ENV_DESC(TRACE_LOADED_OBJECTS_FMT1, false), 400 LD_ENV_DESC(TRACE_LOADED_OBJECTS_FMT2, false), 401 LD_ENV_DESC(TRACE_LOADED_OBJECTS_ALL, false), 402 LD_ENV_DESC(SHOW_AUXV, false), 403 }; 404 405 static const char * 406 ld_get_env_var(int idx) 407 { 408 return (ld_env_vars[idx].val); 409 } 410 411 static const char * 412 rtld_get_env_val(char **env, const char *name, size_t name_len) 413 { 414 char **m, *n, *v; 415 416 for (m = env; *m != NULL; m++) { 417 n = *m; 418 v = strchr(n, '='); 419 if (v == NULL) { 420 /* corrupt environment? */ 421 continue; 422 } 423 if (v - n == (ptrdiff_t)name_len && 424 strncmp(name, n, name_len) == 0) 425 return (v + 1); 426 } 427 return (NULL); 428 } 429 430 static void 431 rtld_init_env_vars_for_prefix(char **env, const char *env_prefix) 432 { 433 struct ld_env_var_desc *lvd; 434 size_t prefix_len, nlen; 435 char **m, *n, *v; 436 int i; 437 438 prefix_len = strlen(env_prefix); 439 for (m = env; *m != NULL; m++) { 440 n = *m; 441 if (strncmp(env_prefix, n, prefix_len) != 0) { 442 /* Not a rtld environment variable. */ 443 continue; 444 } 445 n += prefix_len; 446 v = strchr(n, '='); 447 if (v == NULL) { 448 /* corrupt environment? */ 449 continue; 450 } 451 for (i = 0; i < (int)nitems(ld_env_vars); i++) { 452 lvd = &ld_env_vars[i]; 453 if (lvd->val != NULL) { 454 /* Saw higher-priority variable name already. */ 455 continue; 456 } 457 nlen = strlen(lvd->n); 458 if (v - n == (ptrdiff_t)nlen && 459 strncmp(lvd->n, n, nlen) == 0) { 460 lvd->val = v + 1; 461 break; 462 } 463 } 464 } 465 } 466 467 static void 468 rtld_init_env_vars(char **env) 469 { 470 rtld_init_env_vars_for_prefix(env, ld_env_prefix); 471 } 472 473 static void 474 set_ld_elf_hints_path(void) 475 { 476 if (ld_elf_hints_path == NULL || strlen(ld_elf_hints_path) == 0) 477 ld_elf_hints_path = ld_elf_hints_default; 478 } 479 480 uintptr_t 481 rtld_round_page(uintptr_t x) 482 { 483 return (roundup2(x, page_size)); 484 } 485 486 uintptr_t 487 rtld_trunc_page(uintptr_t x) 488 { 489 return (rounddown2(x, page_size)); 490 } 491 492 /* 493 * Main entry point for dynamic linking. The first argument is the 494 * stack pointer. The stack is expected to be laid out as described 495 * in the SVR4 ABI specification, Intel 386 Processor Supplement. 496 * Specifically, the stack pointer points to a word containing 497 * ARGC. Following that in the stack is a null-terminated sequence 498 * of pointers to argument strings. Then comes a null-terminated 499 * sequence of pointers to environment strings. Finally, there is a 500 * sequence of "auxiliary vector" entries. 501 * 502 * The second argument points to a place to store the dynamic linker's 503 * exit procedure pointer and the third to a place to store the main 504 * program's object. 505 * 506 * The return value is the main program's entry point. 507 */ 508 func_ptr_type 509 _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp) 510 { 511 Elf_Auxinfo *aux, *auxp, *auxpf, *aux_info[AT_COUNT]; 512 Objlist_Entry *entry; 513 Obj_Entry *last_interposer, *obj, *preload_tail; 514 const Elf_Phdr *phdr; 515 Objlist initlist; 516 RtldLockState lockstate; 517 struct stat st; 518 Elf_Addr *argcp; 519 char **argv, **env, **envp, *kexecpath; 520 const char *argv0, *binpath, *library_path_rpath; 521 struct ld_env_var_desc *lvd; 522 caddr_t imgentry; 523 char buf[MAXPATHLEN]; 524 int argc, fd, i, mib[4], old_osrel, osrel, phnum, rtld_argc; 525 size_t sz; 526 #ifdef __powerpc__ 527 int old_auxv_format = 1; 528 #endif 529 bool dir_enable, dir_ignore, direct_exec, explicit_fd, search_in_path; 530 531 /* 532 * On entry, the dynamic linker itself has not been relocated yet. 533 * Be very careful not to reference any global data until after 534 * init_rtld has returned. It is OK to reference file-scope statics 535 * and string constants, and to call static and global functions. 536 */ 537 538 /* Find the auxiliary vector on the stack. */ 539 argcp = sp; 540 argc = *sp++; 541 argv = (char **) sp; 542 sp += argc + 1; /* Skip over arguments and NULL terminator */ 543 env = (char **) sp; 544 while (*sp++ != 0) /* Skip over environment, and NULL terminator */ 545 ; 546 aux = (Elf_Auxinfo *) sp; 547 548 /* Digest the auxiliary vector. */ 549 for (i = 0; i < AT_COUNT; i++) 550 aux_info[i] = NULL; 551 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) { 552 if (auxp->a_type < AT_COUNT) 553 aux_info[auxp->a_type] = auxp; 554 #ifdef __powerpc__ 555 if (auxp->a_type == 23) /* AT_STACKPROT */ 556 old_auxv_format = 0; 557 #endif 558 } 559 560 #ifdef __powerpc__ 561 if (old_auxv_format) { 562 /* Remap from old-style auxv numbers. */ 563 aux_info[23] = aux_info[21]; /* AT_STACKPROT */ 564 aux_info[21] = aux_info[19]; /* AT_PAGESIZESLEN */ 565 aux_info[19] = aux_info[17]; /* AT_NCPUS */ 566 aux_info[17] = aux_info[15]; /* AT_CANARYLEN */ 567 aux_info[15] = aux_info[13]; /* AT_EXECPATH */ 568 aux_info[13] = NULL; /* AT_GID */ 569 570 aux_info[20] = aux_info[18]; /* AT_PAGESIZES */ 571 aux_info[18] = aux_info[16]; /* AT_OSRELDATE */ 572 aux_info[16] = aux_info[14]; /* AT_CANARY */ 573 aux_info[14] = NULL; /* AT_EGID */ 574 } 575 #endif 576 577 /* Initialize and relocate ourselves. */ 578 assert(aux_info[AT_BASE] != NULL); 579 init_rtld((caddr_t) aux_info[AT_BASE]->a_un.a_ptr, aux_info); 580 581 dlerror_dflt_init(); 582 583 __progname = obj_rtld.path; 584 argv0 = argv[0] != NULL ? argv[0] : "(null)"; 585 environ = env; 586 main_argc = argc; 587 main_argv = argv; 588 589 if (aux_info[AT_BSDFLAGS] != NULL && 590 (aux_info[AT_BSDFLAGS]->a_un.a_val & ELF_BSDF_SIGFASTBLK) != 0) 591 ld_fast_sigblock = true; 592 593 trust = !issetugid(); 594 direct_exec = false; 595 596 md_abi_variant_hook(aux_info); 597 rtld_init_env_vars(env); 598 599 fd = -1; 600 if (aux_info[AT_EXECFD] != NULL) { 601 fd = aux_info[AT_EXECFD]->a_un.a_val; 602 } else { 603 assert(aux_info[AT_PHDR] != NULL); 604 phdr = (const Elf_Phdr *)aux_info[AT_PHDR]->a_un.a_ptr; 605 if (phdr == obj_rtld.phdr) { 606 if (!trust) { 607 _rtld_error("Tainted process refusing to run binary %s", 608 argv0); 609 rtld_die(); 610 } 611 direct_exec = true; 612 613 dbg("opening main program in direct exec mode"); 614 if (argc >= 2) { 615 rtld_argc = parse_args(argv, argc, &search_in_path, &fd, 616 &argv0, &dir_ignore); 617 explicit_fd = (fd != -1); 618 binpath = NULL; 619 if (!explicit_fd) 620 fd = open_binary_fd(argv0, search_in_path, &binpath); 621 if (fstat(fd, &st) == -1) { 622 _rtld_error("Failed to fstat FD %d (%s): %s", fd, 623 explicit_fd ? "user-provided descriptor" : argv0, 624 rtld_strerror(errno)); 625 rtld_die(); 626 } 627 628 /* 629 * Rough emulation of the permission checks done by 630 * execve(2), only Unix DACs are checked, ACLs are 631 * ignored. Preserve the semantic of disabling owner 632 * to execute if owner x bit is cleared, even if 633 * others x bit is enabled. 634 * mmap(2) does not allow to mmap with PROT_EXEC if 635 * binary' file comes from noexec mount. We cannot 636 * set a text reference on the binary. 637 */ 638 dir_enable = false; 639 if (st.st_uid == geteuid()) { 640 if ((st.st_mode & S_IXUSR) != 0) 641 dir_enable = true; 642 } else if (st.st_gid == getegid()) { 643 if ((st.st_mode & S_IXGRP) != 0) 644 dir_enable = true; 645 } else if ((st.st_mode & S_IXOTH) != 0) { 646 dir_enable = true; 647 } 648 if (!dir_enable && !dir_ignore) { 649 _rtld_error("No execute permission for binary %s", 650 argv0); 651 rtld_die(); 652 } 653 654 /* 655 * For direct exec mode, argv[0] is the interpreter 656 * name, we must remove it and shift arguments left 657 * before invoking binary main. Since stack layout 658 * places environment pointers and aux vectors right 659 * after the terminating NULL, we must shift 660 * environment and aux as well. 661 */ 662 main_argc = argc - rtld_argc; 663 for (i = 0; i <= main_argc; i++) 664 argv[i] = argv[i + rtld_argc]; 665 *argcp -= rtld_argc; 666 environ = env = envp = argv + main_argc + 1; 667 dbg("move env from %p to %p", envp + rtld_argc, envp); 668 do { 669 *envp = *(envp + rtld_argc); 670 } while (*envp++ != NULL); 671 aux = auxp = (Elf_Auxinfo *)envp; 672 auxpf = (Elf_Auxinfo *)(envp + rtld_argc); 673 dbg("move aux from %p to %p", auxpf, aux); 674 /* XXXKIB insert place for AT_EXECPATH if not present */ 675 for (;; auxp++, auxpf++) { 676 *auxp = *auxpf; 677 if (auxp->a_type == AT_NULL) 678 break; 679 } 680 /* Since the auxiliary vector has moved, redigest it. */ 681 for (i = 0; i < AT_COUNT; i++) 682 aux_info[i] = NULL; 683 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) { 684 if (auxp->a_type < AT_COUNT) 685 aux_info[auxp->a_type] = auxp; 686 } 687 688 /* Point AT_EXECPATH auxv and aux_info to the binary path. */ 689 if (binpath == NULL) { 690 aux_info[AT_EXECPATH] = NULL; 691 } else { 692 if (aux_info[AT_EXECPATH] == NULL) { 693 aux_info[AT_EXECPATH] = xmalloc(sizeof(Elf_Auxinfo)); 694 aux_info[AT_EXECPATH]->a_type = AT_EXECPATH; 695 } 696 aux_info[AT_EXECPATH]->a_un.a_ptr = __DECONST(void *, 697 binpath); 698 } 699 } else { 700 _rtld_error("No binary"); 701 rtld_die(); 702 } 703 } 704 } 705 706 ld_bind_now = ld_get_env_var(LD_BIND_NOW); 707 708 /* 709 * If the process is tainted, then we un-set the dangerous environment 710 * variables. The process will be marked as tainted until setuid(2) 711 * is called. If any child process calls setuid(2) we do not want any 712 * future processes to honor the potentially un-safe variables. 713 */ 714 if (!trust) { 715 for (i = 0; i < (int)nitems(ld_env_vars); i++) { 716 lvd = &ld_env_vars[i]; 717 if (lvd->unsecure) 718 lvd->val = NULL; 719 } 720 } 721 722 ld_debug = ld_get_env_var(LD_DEBUG); 723 if (ld_bind_now == NULL) 724 ld_bind_not = ld_get_env_var(LD_BIND_NOT) != NULL; 725 ld_dynamic_weak = ld_get_env_var(LD_DYNAMIC_WEAK) == NULL; 726 libmap_disable = ld_get_env_var(LD_LIBMAP_DISABLE) != NULL; 727 libmap_override = ld_get_env_var(LD_LIBMAP); 728 ld_library_path = ld_get_env_var(LD_LIBRARY_PATH); 729 ld_library_dirs = ld_get_env_var(LD_LIBRARY_PATH_FDS); 730 ld_preload = ld_get_env_var(LD_PRELOAD); 731 ld_preload_fds = ld_get_env_var(LD_PRELOAD_FDS); 732 ld_elf_hints_path = ld_get_env_var(LD_ELF_HINTS_PATH); 733 ld_loadfltr = ld_get_env_var(LD_LOADFLTR) != NULL; 734 library_path_rpath = ld_get_env_var(LD_LIBRARY_PATH_RPATH); 735 if (library_path_rpath != NULL) { 736 if (library_path_rpath[0] == 'y' || 737 library_path_rpath[0] == 'Y' || 738 library_path_rpath[0] == '1') 739 ld_library_path_rpath = true; 740 else 741 ld_library_path_rpath = false; 742 } 743 dangerous_ld_env = libmap_disable || libmap_override != NULL || 744 ld_library_path != NULL || ld_preload != NULL || 745 ld_elf_hints_path != NULL || ld_loadfltr || !ld_dynamic_weak; 746 ld_tracing = ld_get_env_var(LD_TRACE_LOADED_OBJECTS); 747 ld_utrace = ld_get_env_var(LD_UTRACE); 748 749 set_ld_elf_hints_path(); 750 if (ld_debug != NULL && *ld_debug != '\0') 751 debug = 1; 752 dbg("%s is initialized, base address = %p", __progname, 753 (caddr_t) aux_info[AT_BASE]->a_un.a_ptr); 754 dbg("RTLD dynamic = %p", obj_rtld.dynamic); 755 dbg("RTLD pltgot = %p", obj_rtld.pltgot); 756 757 dbg("initializing thread locks"); 758 lockdflt_init(); 759 760 /* 761 * Load the main program, or process its program header if it is 762 * already loaded. 763 */ 764 if (fd != -1) { /* Load the main program. */ 765 dbg("loading main program"); 766 obj_main = map_object(fd, argv0, NULL); 767 close(fd); 768 if (obj_main == NULL) 769 rtld_die(); 770 max_stack_flags = obj_main->stack_flags; 771 } else { /* Main program already loaded. */ 772 dbg("processing main program's program header"); 773 assert(aux_info[AT_PHDR] != NULL); 774 phdr = (const Elf_Phdr *) aux_info[AT_PHDR]->a_un.a_ptr; 775 assert(aux_info[AT_PHNUM] != NULL); 776 phnum = aux_info[AT_PHNUM]->a_un.a_val; 777 assert(aux_info[AT_PHENT] != NULL); 778 assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr)); 779 assert(aux_info[AT_ENTRY] != NULL); 780 imgentry = (caddr_t) aux_info[AT_ENTRY]->a_un.a_ptr; 781 if ((obj_main = digest_phdr(phdr, phnum, imgentry, argv0)) == NULL) 782 rtld_die(); 783 } 784 785 if (aux_info[AT_EXECPATH] != NULL && fd == -1) { 786 kexecpath = aux_info[AT_EXECPATH]->a_un.a_ptr; 787 dbg("AT_EXECPATH %p %s", kexecpath, kexecpath); 788 if (kexecpath[0] == '/') 789 obj_main->path = kexecpath; 790 else if (getcwd(buf, sizeof(buf)) == NULL || 791 strlcat(buf, "/", sizeof(buf)) >= sizeof(buf) || 792 strlcat(buf, kexecpath, sizeof(buf)) >= sizeof(buf)) 793 obj_main->path = xstrdup(argv0); 794 else 795 obj_main->path = xstrdup(buf); 796 } else { 797 dbg("No AT_EXECPATH or direct exec"); 798 obj_main->path = xstrdup(argv0); 799 } 800 dbg("obj_main path %s", obj_main->path); 801 obj_main->mainprog = true; 802 803 if (aux_info[AT_STACKPROT] != NULL && 804 aux_info[AT_STACKPROT]->a_un.a_val != 0) 805 stack_prot = aux_info[AT_STACKPROT]->a_un.a_val; 806 807 #ifndef COMPAT_32BIT 808 /* 809 * Get the actual dynamic linker pathname from the executable if 810 * possible. (It should always be possible.) That ensures that 811 * gdb will find the right dynamic linker even if a non-standard 812 * one is being used. 813 */ 814 if (obj_main->interp != NULL && 815 strcmp(obj_main->interp, obj_rtld.path) != 0) { 816 free(obj_rtld.path); 817 obj_rtld.path = xstrdup(obj_main->interp); 818 __progname = obj_rtld.path; 819 } 820 #endif 821 822 if (!digest_dynamic(obj_main, 0)) 823 rtld_die(); 824 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", 825 obj_main->path, obj_main->valid_hash_sysv, obj_main->valid_hash_gnu, 826 obj_main->dynsymcount); 827 828 linkmap_add(obj_main); 829 linkmap_add(&obj_rtld); 830 831 /* Link the main program into the list of objects. */ 832 TAILQ_INSERT_HEAD(&obj_list, obj_main, next); 833 obj_count++; 834 obj_loads++; 835 836 /* Initialize a fake symbol for resolving undefined weak references. */ 837 sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE); 838 sym_zero.st_shndx = SHN_UNDEF; 839 sym_zero.st_value = -(uintptr_t)obj_main->relocbase; 840 841 if (!libmap_disable) 842 libmap_disable = (bool)lm_init(libmap_override); 843 844 if (aux_info[AT_KPRELOAD] != NULL && 845 aux_info[AT_KPRELOAD]->a_un.a_ptr != NULL) { 846 dbg("loading kernel vdso"); 847 if (load_kpreload(aux_info[AT_KPRELOAD]->a_un.a_ptr) == -1) 848 rtld_die(); 849 } 850 851 dbg("loading LD_PRELOAD_FDS libraries"); 852 if (load_preload_objects(ld_preload_fds, true) == -1) 853 rtld_die(); 854 855 dbg("loading LD_PRELOAD libraries"); 856 if (load_preload_objects(ld_preload, false) == -1) 857 rtld_die(); 858 preload_tail = globallist_curr(TAILQ_LAST(&obj_list, obj_entry_q)); 859 860 dbg("loading needed objects"); 861 if (load_needed_objects(obj_main, ld_tracing != NULL ? RTLD_LO_TRACE : 862 0) == -1) 863 rtld_die(); 864 865 /* Make a list of all objects loaded at startup. */ 866 last_interposer = obj_main; 867 TAILQ_FOREACH(obj, &obj_list, next) { 868 if (obj->marker) 869 continue; 870 if (obj->z_interpose && obj != obj_main) { 871 objlist_put_after(&list_main, last_interposer, obj); 872 last_interposer = obj; 873 } else { 874 objlist_push_tail(&list_main, obj); 875 } 876 obj->refcount++; 877 } 878 879 dbg("checking for required versions"); 880 if (rtld_verify_versions(&list_main) == -1 && !ld_tracing) 881 rtld_die(); 882 883 if (ld_get_env_var(LD_SHOW_AUXV) != NULL) 884 dump_auxv(aux_info); 885 886 if (ld_tracing) { /* We're done */ 887 trace_loaded_objects(obj_main, true); 888 exit(0); 889 } 890 891 if (ld_get_env_var(LD_DUMP_REL_PRE) != NULL) { 892 dump_relocations(obj_main); 893 exit (0); 894 } 895 896 /* 897 * Processing tls relocations requires having the tls offsets 898 * initialized. Prepare offsets before starting initial 899 * relocation processing. 900 */ 901 dbg("initializing initial thread local storage offsets"); 902 STAILQ_FOREACH(entry, &list_main, link) { 903 /* 904 * Allocate all the initial objects out of the static TLS 905 * block even if they didn't ask for it. 906 */ 907 allocate_tls_offset(entry->obj); 908 } 909 910 if (relocate_objects(obj_main, 911 ld_bind_now != NULL && *ld_bind_now != '\0', 912 &obj_rtld, SYMLOOK_EARLY, NULL) == -1) 913 rtld_die(); 914 915 dbg("doing copy relocations"); 916 if (do_copy_relocations(obj_main) == -1) 917 rtld_die(); 918 919 if (ld_get_env_var(LD_DUMP_REL_POST) != NULL) { 920 dump_relocations(obj_main); 921 exit (0); 922 } 923 924 ifunc_init(aux); 925 926 /* 927 * Setup TLS for main thread. This must be done after the 928 * relocations are processed, since tls initialization section 929 * might be the subject for relocations. 930 */ 931 dbg("initializing initial thread local storage"); 932 allocate_initial_tls(globallist_curr(TAILQ_FIRST(&obj_list))); 933 934 dbg("initializing key program variables"); 935 set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : ""); 936 set_program_var("environ", env); 937 set_program_var("__elf_aux_vector", aux); 938 939 /* Make a list of init functions to call. */ 940 objlist_init(&initlist); 941 initlist_add_objects(globallist_curr(TAILQ_FIRST(&obj_list)), 942 preload_tail, &initlist); 943 944 r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */ 945 946 map_stacks_exec(NULL); 947 948 if (!obj_main->crt_no_init) { 949 /* 950 * Make sure we don't call the main program's init and fini 951 * functions for binaries linked with old crt1 which calls 952 * _init itself. 953 */ 954 obj_main->init = obj_main->fini = (Elf_Addr)NULL; 955 obj_main->preinit_array = obj_main->init_array = 956 obj_main->fini_array = (Elf_Addr)NULL; 957 } 958 959 if (direct_exec) { 960 /* Set osrel for direct-execed binary */ 961 mib[0] = CTL_KERN; 962 mib[1] = KERN_PROC; 963 mib[2] = KERN_PROC_OSREL; 964 mib[3] = getpid(); 965 osrel = obj_main->osrel; 966 sz = sizeof(old_osrel); 967 dbg("setting osrel to %d", osrel); 968 (void)sysctl(mib, 4, &old_osrel, &sz, &osrel, sizeof(osrel)); 969 } 970 971 wlock_acquire(rtld_bind_lock, &lockstate); 972 973 dbg("resolving ifuncs"); 974 if (initlist_objects_ifunc(&initlist, ld_bind_now != NULL && 975 *ld_bind_now != '\0', SYMLOOK_EARLY, &lockstate) == -1) 976 rtld_die(); 977 978 rtld_exit_ptr = rtld_exit; 979 if (obj_main->crt_no_init) 980 preinit_main(); 981 objlist_call_init(&initlist, &lockstate); 982 _r_debug_postinit(&obj_main->linkmap); 983 objlist_clear(&initlist); 984 dbg("loading filtees"); 985 TAILQ_FOREACH(obj, &obj_list, next) { 986 if (obj->marker) 987 continue; 988 if (ld_loadfltr || obj->z_loadfltr) 989 load_filtees(obj, 0, &lockstate); 990 } 991 992 dbg("enforcing main obj relro"); 993 if (obj_enforce_relro(obj_main) == -1) 994 rtld_die(); 995 996 lock_release(rtld_bind_lock, &lockstate); 997 998 dbg("transferring control to program entry point = %p", obj_main->entry); 999 1000 /* Return the exit procedure and the program entry point. */ 1001 *exit_proc = rtld_exit_ptr; 1002 *objp = obj_main; 1003 return ((func_ptr_type)obj_main->entry); 1004 } 1005 1006 void * 1007 rtld_resolve_ifunc(const Obj_Entry *obj, const Elf_Sym *def) 1008 { 1009 void *ptr; 1010 Elf_Addr target; 1011 1012 ptr = (void *)make_function_pointer(def, obj); 1013 target = call_ifunc_resolver(ptr); 1014 return ((void *)target); 1015 } 1016 1017 Elf_Addr 1018 _rtld_bind(Obj_Entry *obj, Elf_Size reloff) 1019 { 1020 const Elf_Rel *rel; 1021 const Elf_Sym *def; 1022 const Obj_Entry *defobj; 1023 Elf_Addr *where; 1024 Elf_Addr target; 1025 RtldLockState lockstate; 1026 1027 rlock_acquire(rtld_bind_lock, &lockstate); 1028 if (sigsetjmp(lockstate.env, 0) != 0) 1029 lock_upgrade(rtld_bind_lock, &lockstate); 1030 if (obj->pltrel) 1031 rel = (const Elf_Rel *)((const char *)obj->pltrel + reloff); 1032 else 1033 rel = (const Elf_Rel *)((const char *)obj->pltrela + reloff); 1034 1035 where = (Elf_Addr *)(obj->relocbase + rel->r_offset); 1036 def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, SYMLOOK_IN_PLT, 1037 NULL, &lockstate); 1038 if (def == NULL) 1039 rtld_die(); 1040 if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 1041 target = (Elf_Addr)rtld_resolve_ifunc(defobj, def); 1042 else 1043 target = (Elf_Addr)(defobj->relocbase + def->st_value); 1044 1045 dbg("\"%s\" in \"%s\" ==> %p in \"%s\"", 1046 defobj->strtab + def->st_name, 1047 obj->path == NULL ? NULL : basename(obj->path), 1048 (void *)target, 1049 defobj->path == NULL ? NULL : basename(defobj->path)); 1050 1051 /* 1052 * Write the new contents for the jmpslot. Note that depending on 1053 * architecture, the value which we need to return back to the 1054 * lazy binding trampoline may or may not be the target 1055 * address. The value returned from reloc_jmpslot() is the value 1056 * that the trampoline needs. 1057 */ 1058 target = reloc_jmpslot(where, target, defobj, obj, rel); 1059 lock_release(rtld_bind_lock, &lockstate); 1060 return (target); 1061 } 1062 1063 /* 1064 * Error reporting function. Use it like printf. If formats the message 1065 * into a buffer, and sets things up so that the next call to dlerror() 1066 * will return the message. 1067 */ 1068 void 1069 _rtld_error(const char *fmt, ...) 1070 { 1071 va_list ap; 1072 1073 va_start(ap, fmt); 1074 rtld_vsnprintf(lockinfo.dlerror_loc(), lockinfo.dlerror_loc_sz, 1075 fmt, ap); 1076 va_end(ap); 1077 *lockinfo.dlerror_seen() = 0; 1078 LD_UTRACE(UTRACE_RTLD_ERROR, NULL, NULL, 0, 0, lockinfo.dlerror_loc()); 1079 } 1080 1081 /* 1082 * Return a dynamically-allocated copy of the current error message, if any. 1083 */ 1084 static struct dlerror_save * 1085 errmsg_save(void) 1086 { 1087 struct dlerror_save *res; 1088 1089 res = xmalloc(sizeof(*res)); 1090 res->seen = *lockinfo.dlerror_seen(); 1091 if (res->seen == 0) 1092 res->msg = xstrdup(lockinfo.dlerror_loc()); 1093 return (res); 1094 } 1095 1096 /* 1097 * Restore the current error message from a copy which was previously saved 1098 * by errmsg_save(). The copy is freed. 1099 */ 1100 static void 1101 errmsg_restore(struct dlerror_save *saved_msg) 1102 { 1103 if (saved_msg == NULL || saved_msg->seen == 1) { 1104 *lockinfo.dlerror_seen() = 1; 1105 } else { 1106 *lockinfo.dlerror_seen() = 0; 1107 strlcpy(lockinfo.dlerror_loc(), saved_msg->msg, 1108 lockinfo.dlerror_loc_sz); 1109 free(saved_msg->msg); 1110 } 1111 free(saved_msg); 1112 } 1113 1114 static const char * 1115 basename(const char *name) 1116 { 1117 const char *p; 1118 1119 p = strrchr(name, '/'); 1120 return (p != NULL ? p + 1 : name); 1121 } 1122 1123 static struct utsname uts; 1124 1125 static char * 1126 origin_subst_one(Obj_Entry *obj, char *real, const char *kw, 1127 const char *subst, bool may_free) 1128 { 1129 char *p, *p1, *res, *resp; 1130 int subst_len, kw_len, subst_count, old_len, new_len; 1131 1132 kw_len = strlen(kw); 1133 1134 /* 1135 * First, count the number of the keyword occurrences, to 1136 * preallocate the final string. 1137 */ 1138 for (p = real, subst_count = 0;; p = p1 + kw_len, subst_count++) { 1139 p1 = strstr(p, kw); 1140 if (p1 == NULL) 1141 break; 1142 } 1143 1144 /* 1145 * If the keyword is not found, just return. 1146 * 1147 * Return non-substituted string if resolution failed. We 1148 * cannot do anything more reasonable, the failure mode of the 1149 * caller is unresolved library anyway. 1150 */ 1151 if (subst_count == 0 || (obj != NULL && !obj_resolve_origin(obj))) 1152 return (may_free ? real : xstrdup(real)); 1153 if (obj != NULL) 1154 subst = obj->origin_path; 1155 1156 /* 1157 * There is indeed something to substitute. Calculate the 1158 * length of the resulting string, and allocate it. 1159 */ 1160 subst_len = strlen(subst); 1161 old_len = strlen(real); 1162 new_len = old_len + (subst_len - kw_len) * subst_count; 1163 res = xmalloc(new_len + 1); 1164 1165 /* 1166 * Now, execute the substitution loop. 1167 */ 1168 for (p = real, resp = res, *resp = '\0';;) { 1169 p1 = strstr(p, kw); 1170 if (p1 != NULL) { 1171 /* Copy the prefix before keyword. */ 1172 memcpy(resp, p, p1 - p); 1173 resp += p1 - p; 1174 /* Keyword replacement. */ 1175 memcpy(resp, subst, subst_len); 1176 resp += subst_len; 1177 *resp = '\0'; 1178 p = p1 + kw_len; 1179 } else 1180 break; 1181 } 1182 1183 /* Copy to the end of string and finish. */ 1184 strcat(resp, p); 1185 if (may_free) 1186 free(real); 1187 return (res); 1188 } 1189 1190 static const struct { 1191 const char *kw; 1192 bool pass_obj; 1193 const char *subst; 1194 } tokens[] = { 1195 { .kw = "$ORIGIN", .pass_obj = true, .subst = NULL }, 1196 { .kw = "${ORIGIN}", .pass_obj = true, .subst = NULL }, 1197 { .kw = "$OSNAME", .pass_obj = false, .subst = uts.sysname }, 1198 { .kw = "${OSNAME}", .pass_obj = false, .subst = uts.sysname }, 1199 { .kw = "$OSREL", .pass_obj = false, .subst = uts.release }, 1200 { .kw = "${OSREL}", .pass_obj = false, .subst = uts.release }, 1201 { .kw = "$PLATFORM", .pass_obj = false, .subst = uts.machine }, 1202 { .kw = "${PLATFORM}", .pass_obj = false, .subst = uts.machine }, 1203 { .kw = "$LIB", .pass_obj = false, .subst = TOKEN_LIB }, 1204 { .kw = "${LIB}", .pass_obj = false, .subst = TOKEN_LIB }, 1205 }; 1206 1207 static char * 1208 origin_subst(Obj_Entry *obj, const char *real) 1209 { 1210 char *res; 1211 int i; 1212 1213 if (obj == NULL || !trust) 1214 return (xstrdup(real)); 1215 if (uts.sysname[0] == '\0') { 1216 if (uname(&uts) != 0) { 1217 _rtld_error("utsname failed: %d", errno); 1218 return (NULL); 1219 } 1220 } 1221 1222 /* __DECONST is safe here since without may_free real is unchanged */ 1223 res = __DECONST(char *, real); 1224 for (i = 0; i < (int)nitems(tokens); i++) { 1225 res = origin_subst_one(tokens[i].pass_obj ? obj : NULL, 1226 res, tokens[i].kw, tokens[i].subst, i != 0); 1227 } 1228 return (res); 1229 } 1230 1231 void 1232 rtld_die(void) 1233 { 1234 const char *msg = dlerror(); 1235 1236 if (msg == NULL) 1237 msg = "Fatal error"; 1238 rtld_fdputstr(STDERR_FILENO, _BASENAME_RTLD ": "); 1239 rtld_fdputstr(STDERR_FILENO, msg); 1240 rtld_fdputchar(STDERR_FILENO, '\n'); 1241 _exit(1); 1242 } 1243 1244 /* 1245 * Process a shared object's DYNAMIC section, and save the important 1246 * information in its Obj_Entry structure. 1247 */ 1248 static void 1249 digest_dynamic1(Obj_Entry *obj, int early, const Elf_Dyn **dyn_rpath, 1250 const Elf_Dyn **dyn_soname, const Elf_Dyn **dyn_runpath) 1251 { 1252 const Elf_Dyn *dynp; 1253 Needed_Entry **needed_tail = &obj->needed; 1254 Needed_Entry **needed_filtees_tail = &obj->needed_filtees; 1255 Needed_Entry **needed_aux_filtees_tail = &obj->needed_aux_filtees; 1256 const Elf_Hashelt *hashtab; 1257 const Elf32_Word *hashval; 1258 Elf32_Word bkt, nmaskwords; 1259 int bloom_size32; 1260 int plttype = DT_REL; 1261 1262 *dyn_rpath = NULL; 1263 *dyn_soname = NULL; 1264 *dyn_runpath = NULL; 1265 1266 obj->bind_now = false; 1267 dynp = obj->dynamic; 1268 if (dynp == NULL) 1269 return; 1270 for (; dynp->d_tag != DT_NULL; dynp++) { 1271 switch (dynp->d_tag) { 1272 1273 case DT_REL: 1274 obj->rel = (const Elf_Rel *)(obj->relocbase + dynp->d_un.d_ptr); 1275 break; 1276 1277 case DT_RELSZ: 1278 obj->relsize = dynp->d_un.d_val; 1279 break; 1280 1281 case DT_RELENT: 1282 assert(dynp->d_un.d_val == sizeof(Elf_Rel)); 1283 break; 1284 1285 case DT_JMPREL: 1286 obj->pltrel = (const Elf_Rel *) 1287 (obj->relocbase + dynp->d_un.d_ptr); 1288 break; 1289 1290 case DT_PLTRELSZ: 1291 obj->pltrelsize = dynp->d_un.d_val; 1292 break; 1293 1294 case DT_RELA: 1295 obj->rela = (const Elf_Rela *)(obj->relocbase + dynp->d_un.d_ptr); 1296 break; 1297 1298 case DT_RELASZ: 1299 obj->relasize = dynp->d_un.d_val; 1300 break; 1301 1302 case DT_RELAENT: 1303 assert(dynp->d_un.d_val == sizeof(Elf_Rela)); 1304 break; 1305 1306 case DT_RELR: 1307 obj->relr = (const Elf_Relr *)(obj->relocbase + dynp->d_un.d_ptr); 1308 break; 1309 1310 case DT_RELRSZ: 1311 obj->relrsize = dynp->d_un.d_val; 1312 break; 1313 1314 case DT_RELRENT: 1315 assert(dynp->d_un.d_val == sizeof(Elf_Relr)); 1316 break; 1317 1318 case DT_PLTREL: 1319 plttype = dynp->d_un.d_val; 1320 assert(dynp->d_un.d_val == DT_REL || plttype == DT_RELA); 1321 break; 1322 1323 case DT_SYMTAB: 1324 obj->symtab = (const Elf_Sym *) 1325 (obj->relocbase + dynp->d_un.d_ptr); 1326 break; 1327 1328 case DT_SYMENT: 1329 assert(dynp->d_un.d_val == sizeof(Elf_Sym)); 1330 break; 1331 1332 case DT_STRTAB: 1333 obj->strtab = (const char *)(obj->relocbase + dynp->d_un.d_ptr); 1334 break; 1335 1336 case DT_STRSZ: 1337 obj->strsize = dynp->d_un.d_val; 1338 break; 1339 1340 case DT_VERNEED: 1341 obj->verneed = (const Elf_Verneed *)(obj->relocbase + 1342 dynp->d_un.d_val); 1343 break; 1344 1345 case DT_VERNEEDNUM: 1346 obj->verneednum = dynp->d_un.d_val; 1347 break; 1348 1349 case DT_VERDEF: 1350 obj->verdef = (const Elf_Verdef *)(obj->relocbase + 1351 dynp->d_un.d_val); 1352 break; 1353 1354 case DT_VERDEFNUM: 1355 obj->verdefnum = dynp->d_un.d_val; 1356 break; 1357 1358 case DT_VERSYM: 1359 obj->versyms = (const Elf_Versym *)(obj->relocbase + 1360 dynp->d_un.d_val); 1361 break; 1362 1363 case DT_HASH: 1364 { 1365 hashtab = (const Elf_Hashelt *)(obj->relocbase + 1366 dynp->d_un.d_ptr); 1367 obj->nbuckets = hashtab[0]; 1368 obj->nchains = hashtab[1]; 1369 obj->buckets = hashtab + 2; 1370 obj->chains = obj->buckets + obj->nbuckets; 1371 obj->valid_hash_sysv = obj->nbuckets > 0 && obj->nchains > 0 && 1372 obj->buckets != NULL; 1373 } 1374 break; 1375 1376 case DT_GNU_HASH: 1377 { 1378 hashtab = (const Elf_Hashelt *)(obj->relocbase + 1379 dynp->d_un.d_ptr); 1380 obj->nbuckets_gnu = hashtab[0]; 1381 obj->symndx_gnu = hashtab[1]; 1382 nmaskwords = hashtab[2]; 1383 bloom_size32 = (__ELF_WORD_SIZE / 32) * nmaskwords; 1384 obj->maskwords_bm_gnu = nmaskwords - 1; 1385 obj->shift2_gnu = hashtab[3]; 1386 obj->bloom_gnu = (const Elf_Addr *)(hashtab + 4); 1387 obj->buckets_gnu = hashtab + 4 + bloom_size32; 1388 obj->chain_zero_gnu = obj->buckets_gnu + obj->nbuckets_gnu - 1389 obj->symndx_gnu; 1390 /* Number of bitmask words is required to be power of 2 */ 1391 obj->valid_hash_gnu = powerof2(nmaskwords) && 1392 obj->nbuckets_gnu > 0 && obj->buckets_gnu != NULL; 1393 } 1394 break; 1395 1396 case DT_NEEDED: 1397 if (!obj->rtld) { 1398 Needed_Entry *nep = NEW(Needed_Entry); 1399 nep->name = dynp->d_un.d_val; 1400 nep->obj = NULL; 1401 nep->next = NULL; 1402 1403 *needed_tail = nep; 1404 needed_tail = &nep->next; 1405 } 1406 break; 1407 1408 case DT_FILTER: 1409 if (!obj->rtld) { 1410 Needed_Entry *nep = NEW(Needed_Entry); 1411 nep->name = dynp->d_un.d_val; 1412 nep->obj = NULL; 1413 nep->next = NULL; 1414 1415 *needed_filtees_tail = nep; 1416 needed_filtees_tail = &nep->next; 1417 1418 if (obj->linkmap.l_refname == NULL) 1419 obj->linkmap.l_refname = (char *)dynp->d_un.d_val; 1420 } 1421 break; 1422 1423 case DT_AUXILIARY: 1424 if (!obj->rtld) { 1425 Needed_Entry *nep = NEW(Needed_Entry); 1426 nep->name = dynp->d_un.d_val; 1427 nep->obj = NULL; 1428 nep->next = NULL; 1429 1430 *needed_aux_filtees_tail = nep; 1431 needed_aux_filtees_tail = &nep->next; 1432 } 1433 break; 1434 1435 case DT_PLTGOT: 1436 obj->pltgot = (Elf_Addr *)(obj->relocbase + dynp->d_un.d_ptr); 1437 break; 1438 1439 case DT_TEXTREL: 1440 obj->textrel = true; 1441 break; 1442 1443 case DT_SYMBOLIC: 1444 obj->symbolic = true; 1445 break; 1446 1447 case DT_RPATH: 1448 /* 1449 * We have to wait until later to process this, because we 1450 * might not have gotten the address of the string table yet. 1451 */ 1452 *dyn_rpath = dynp; 1453 break; 1454 1455 case DT_SONAME: 1456 *dyn_soname = dynp; 1457 break; 1458 1459 case DT_RUNPATH: 1460 *dyn_runpath = dynp; 1461 break; 1462 1463 case DT_INIT: 1464 obj->init = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1465 break; 1466 1467 case DT_PREINIT_ARRAY: 1468 obj->preinit_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1469 break; 1470 1471 case DT_PREINIT_ARRAYSZ: 1472 obj->preinit_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1473 break; 1474 1475 case DT_INIT_ARRAY: 1476 obj->init_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1477 break; 1478 1479 case DT_INIT_ARRAYSZ: 1480 obj->init_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1481 break; 1482 1483 case DT_FINI: 1484 obj->fini = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1485 break; 1486 1487 case DT_FINI_ARRAY: 1488 obj->fini_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1489 break; 1490 1491 case DT_FINI_ARRAYSZ: 1492 obj->fini_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1493 break; 1494 1495 case DT_DEBUG: 1496 if (!early) 1497 dbg("Filling in DT_DEBUG entry"); 1498 (__DECONST(Elf_Dyn *, dynp))->d_un.d_ptr = (Elf_Addr)&r_debug; 1499 break; 1500 1501 case DT_FLAGS: 1502 if (dynp->d_un.d_val & DF_ORIGIN) 1503 obj->z_origin = true; 1504 if (dynp->d_un.d_val & DF_SYMBOLIC) 1505 obj->symbolic = true; 1506 if (dynp->d_un.d_val & DF_TEXTREL) 1507 obj->textrel = true; 1508 if (dynp->d_un.d_val & DF_BIND_NOW) 1509 obj->bind_now = true; 1510 if (dynp->d_un.d_val & DF_STATIC_TLS) 1511 obj->static_tls = true; 1512 break; 1513 1514 #ifdef __powerpc__ 1515 #ifdef __powerpc64__ 1516 case DT_PPC64_GLINK: 1517 obj->glink = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1518 break; 1519 #else 1520 case DT_PPC_GOT: 1521 obj->gotptr = (Elf_Addr *)(obj->relocbase + dynp->d_un.d_ptr); 1522 break; 1523 #endif 1524 #endif 1525 1526 case DT_FLAGS_1: 1527 if (dynp->d_un.d_val & DF_1_NOOPEN) 1528 obj->z_noopen = true; 1529 if (dynp->d_un.d_val & DF_1_ORIGIN) 1530 obj->z_origin = true; 1531 if (dynp->d_un.d_val & DF_1_GLOBAL) 1532 obj->z_global = true; 1533 if (dynp->d_un.d_val & DF_1_BIND_NOW) 1534 obj->bind_now = true; 1535 if (dynp->d_un.d_val & DF_1_NODELETE) 1536 obj->z_nodelete = true; 1537 if (dynp->d_un.d_val & DF_1_LOADFLTR) 1538 obj->z_loadfltr = true; 1539 if (dynp->d_un.d_val & DF_1_INTERPOSE) 1540 obj->z_interpose = true; 1541 if (dynp->d_un.d_val & DF_1_NODEFLIB) 1542 obj->z_nodeflib = true; 1543 if (dynp->d_un.d_val & DF_1_PIE) 1544 obj->z_pie = true; 1545 break; 1546 1547 default: 1548 if (!early) { 1549 dbg("Ignoring d_tag %ld = %#lx", (long)dynp->d_tag, 1550 (long)dynp->d_tag); 1551 } 1552 break; 1553 } 1554 } 1555 1556 obj->traced = false; 1557 1558 if (plttype == DT_RELA) { 1559 obj->pltrela = (const Elf_Rela *) obj->pltrel; 1560 obj->pltrel = NULL; 1561 obj->pltrelasize = obj->pltrelsize; 1562 obj->pltrelsize = 0; 1563 } 1564 1565 /* Determine size of dynsym table (equal to nchains of sysv hash) */ 1566 if (obj->valid_hash_sysv) 1567 obj->dynsymcount = obj->nchains; 1568 else if (obj->valid_hash_gnu) { 1569 obj->dynsymcount = 0; 1570 for (bkt = 0; bkt < obj->nbuckets_gnu; bkt++) { 1571 if (obj->buckets_gnu[bkt] == 0) 1572 continue; 1573 hashval = &obj->chain_zero_gnu[obj->buckets_gnu[bkt]]; 1574 do 1575 obj->dynsymcount++; 1576 while ((*hashval++ & 1u) == 0); 1577 } 1578 obj->dynsymcount += obj->symndx_gnu; 1579 } 1580 1581 if (obj->linkmap.l_refname != NULL) 1582 obj->linkmap.l_refname = obj->strtab + (unsigned long)obj-> 1583 linkmap.l_refname; 1584 } 1585 1586 static bool 1587 obj_resolve_origin(Obj_Entry *obj) 1588 { 1589 1590 if (obj->origin_path != NULL) 1591 return (true); 1592 obj->origin_path = xmalloc(PATH_MAX); 1593 return (rtld_dirname_abs(obj->path, obj->origin_path) != -1); 1594 } 1595 1596 static bool 1597 digest_dynamic2(Obj_Entry *obj, const Elf_Dyn *dyn_rpath, 1598 const Elf_Dyn *dyn_soname, const Elf_Dyn *dyn_runpath) 1599 { 1600 1601 if (obj->z_origin && !obj_resolve_origin(obj)) 1602 return (false); 1603 1604 if (dyn_runpath != NULL) { 1605 obj->runpath = (const char *)obj->strtab + dyn_runpath->d_un.d_val; 1606 obj->runpath = origin_subst(obj, obj->runpath); 1607 } else if (dyn_rpath != NULL) { 1608 obj->rpath = (const char *)obj->strtab + dyn_rpath->d_un.d_val; 1609 obj->rpath = origin_subst(obj, obj->rpath); 1610 } 1611 if (dyn_soname != NULL) 1612 object_add_name(obj, obj->strtab + dyn_soname->d_un.d_val); 1613 return (true); 1614 } 1615 1616 static bool 1617 digest_dynamic(Obj_Entry *obj, int early) 1618 { 1619 const Elf_Dyn *dyn_rpath; 1620 const Elf_Dyn *dyn_soname; 1621 const Elf_Dyn *dyn_runpath; 1622 1623 digest_dynamic1(obj, early, &dyn_rpath, &dyn_soname, &dyn_runpath); 1624 return (digest_dynamic2(obj, dyn_rpath, dyn_soname, dyn_runpath)); 1625 } 1626 1627 /* 1628 * Process a shared object's program header. This is used only for the 1629 * main program, when the kernel has already loaded the main program 1630 * into memory before calling the dynamic linker. It creates and 1631 * returns an Obj_Entry structure. 1632 */ 1633 static Obj_Entry * 1634 digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path) 1635 { 1636 Obj_Entry *obj; 1637 const Elf_Phdr *phlimit = phdr + phnum; 1638 const Elf_Phdr *ph; 1639 Elf_Addr note_start, note_end; 1640 int nsegs = 0; 1641 1642 obj = obj_new(); 1643 for (ph = phdr; ph < phlimit; ph++) { 1644 if (ph->p_type != PT_PHDR) 1645 continue; 1646 1647 obj->phdr = phdr; 1648 obj->phsize = ph->p_memsz; 1649 obj->relocbase = __DECONST(char *, phdr) - ph->p_vaddr; 1650 break; 1651 } 1652 1653 obj->stack_flags = PF_X | PF_R | PF_W; 1654 1655 for (ph = phdr; ph < phlimit; ph++) { 1656 switch (ph->p_type) { 1657 1658 case PT_INTERP: 1659 obj->interp = (const char *)(ph->p_vaddr + obj->relocbase); 1660 break; 1661 1662 case PT_LOAD: 1663 if (nsegs == 0) { /* First load segment */ 1664 obj->vaddrbase = rtld_trunc_page(ph->p_vaddr); 1665 obj->mapbase = obj->vaddrbase + obj->relocbase; 1666 } else { /* Last load segment */ 1667 obj->mapsize = rtld_round_page(ph->p_vaddr + ph->p_memsz) - 1668 obj->vaddrbase; 1669 } 1670 nsegs++; 1671 break; 1672 1673 case PT_DYNAMIC: 1674 obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + obj->relocbase); 1675 break; 1676 1677 case PT_TLS: 1678 obj->tlsindex = 1; 1679 obj->tlssize = ph->p_memsz; 1680 obj->tlsalign = ph->p_align; 1681 obj->tlsinitsize = ph->p_filesz; 1682 obj->tlsinit = (void*)(ph->p_vaddr + obj->relocbase); 1683 obj->tlspoffset = ph->p_offset; 1684 break; 1685 1686 case PT_GNU_STACK: 1687 obj->stack_flags = ph->p_flags; 1688 break; 1689 1690 case PT_GNU_RELRO: 1691 obj->relro_page = obj->relocbase + rtld_trunc_page(ph->p_vaddr); 1692 obj->relro_size = rtld_trunc_page(ph->p_vaddr + ph->p_memsz) - 1693 rtld_trunc_page(ph->p_vaddr); 1694 break; 1695 1696 case PT_NOTE: 1697 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; 1698 note_end = note_start + ph->p_filesz; 1699 digest_notes(obj, note_start, note_end); 1700 break; 1701 } 1702 } 1703 if (nsegs < 1) { 1704 _rtld_error("%s: too few PT_LOAD segments", path); 1705 return (NULL); 1706 } 1707 1708 obj->entry = entry; 1709 return (obj); 1710 } 1711 1712 void 1713 digest_notes(Obj_Entry *obj, Elf_Addr note_start, Elf_Addr note_end) 1714 { 1715 const Elf_Note *note; 1716 const char *note_name; 1717 uintptr_t p; 1718 1719 for (note = (const Elf_Note *)note_start; (Elf_Addr)note < note_end; 1720 note = (const Elf_Note *)((const char *)(note + 1) + 1721 roundup2(note->n_namesz, sizeof(Elf32_Addr)) + 1722 roundup2(note->n_descsz, sizeof(Elf32_Addr)))) { 1723 if (note->n_namesz != sizeof(NOTE_FREEBSD_VENDOR) || 1724 note->n_descsz != sizeof(int32_t)) 1725 continue; 1726 if (note->n_type != NT_FREEBSD_ABI_TAG && 1727 note->n_type != NT_FREEBSD_FEATURE_CTL && 1728 note->n_type != NT_FREEBSD_NOINIT_TAG) 1729 continue; 1730 note_name = (const char *)(note + 1); 1731 if (strncmp(NOTE_FREEBSD_VENDOR, note_name, 1732 sizeof(NOTE_FREEBSD_VENDOR)) != 0) 1733 continue; 1734 switch (note->n_type) { 1735 case NT_FREEBSD_ABI_TAG: 1736 /* FreeBSD osrel note */ 1737 p = (uintptr_t)(note + 1); 1738 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1739 obj->osrel = *(const int32_t *)(p); 1740 dbg("note osrel %d", obj->osrel); 1741 break; 1742 case NT_FREEBSD_FEATURE_CTL: 1743 /* FreeBSD ABI feature control note */ 1744 p = (uintptr_t)(note + 1); 1745 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1746 obj->fctl0 = *(const uint32_t *)(p); 1747 dbg("note fctl0 %#x", obj->fctl0); 1748 break; 1749 case NT_FREEBSD_NOINIT_TAG: 1750 /* FreeBSD 'crt does not call init' note */ 1751 obj->crt_no_init = true; 1752 dbg("note crt_no_init"); 1753 break; 1754 } 1755 } 1756 } 1757 1758 static Obj_Entry * 1759 dlcheck(void *handle) 1760 { 1761 Obj_Entry *obj; 1762 1763 TAILQ_FOREACH(obj, &obj_list, next) { 1764 if (obj == (Obj_Entry *) handle) 1765 break; 1766 } 1767 1768 if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) { 1769 _rtld_error("Invalid shared object handle %p", handle); 1770 return (NULL); 1771 } 1772 return (obj); 1773 } 1774 1775 /* 1776 * If the given object is already in the donelist, return true. Otherwise 1777 * add the object to the list and return false. 1778 */ 1779 static bool 1780 donelist_check(DoneList *dlp, const Obj_Entry *obj) 1781 { 1782 unsigned int i; 1783 1784 for (i = 0; i < dlp->num_used; i++) 1785 if (dlp->objs[i] == obj) 1786 return (true); 1787 /* 1788 * Our donelist allocation should always be sufficient. But if 1789 * our threads locking isn't working properly, more shared objects 1790 * could have been loaded since we allocated the list. That should 1791 * never happen, but we'll handle it properly just in case it does. 1792 */ 1793 if (dlp->num_used < dlp->num_alloc) 1794 dlp->objs[dlp->num_used++] = obj; 1795 return (false); 1796 } 1797 1798 /* 1799 * Hash function for symbol table lookup. Don't even think about changing 1800 * this. It is specified by the System V ABI. 1801 */ 1802 unsigned long 1803 elf_hash(const char *name) 1804 { 1805 const unsigned char *p = (const unsigned char *) name; 1806 unsigned long h = 0; 1807 unsigned long g; 1808 1809 while (*p != '\0') { 1810 h = (h << 4) + *p++; 1811 if ((g = h & 0xf0000000) != 0) 1812 h ^= g >> 24; 1813 h &= ~g; 1814 } 1815 return (h); 1816 } 1817 1818 /* 1819 * The GNU hash function is the Daniel J. Bernstein hash clipped to 32 bits 1820 * unsigned in case it's implemented with a wider type. 1821 */ 1822 static uint32_t 1823 gnu_hash(const char *s) 1824 { 1825 uint32_t h; 1826 unsigned char c; 1827 1828 h = 5381; 1829 for (c = *s; c != '\0'; c = *++s) 1830 h = h * 33 + c; 1831 return (h & 0xffffffff); 1832 } 1833 1834 1835 /* 1836 * Find the library with the given name, and return its full pathname. 1837 * The returned string is dynamically allocated. Generates an error 1838 * message and returns NULL if the library cannot be found. 1839 * 1840 * If the second argument is non-NULL, then it refers to an already- 1841 * loaded shared object, whose library search path will be searched. 1842 * 1843 * If a library is successfully located via LD_LIBRARY_PATH_FDS, its 1844 * descriptor (which is close-on-exec) will be passed out via the third 1845 * argument. 1846 * 1847 * The search order is: 1848 * DT_RPATH in the referencing file _unless_ DT_RUNPATH is present (1) 1849 * DT_RPATH of the main object if DSO without defined DT_RUNPATH (1) 1850 * LD_LIBRARY_PATH 1851 * DT_RUNPATH in the referencing file 1852 * ldconfig hints (if -z nodefaultlib, filter out default library directories 1853 * from list) 1854 * /lib:/usr/lib _unless_ the referencing file is linked with -z nodefaultlib 1855 * 1856 * (1) Handled in digest_dynamic2 - rpath left NULL if runpath defined. 1857 */ 1858 static char * 1859 find_library(const char *xname, const Obj_Entry *refobj, int *fdp) 1860 { 1861 char *pathname, *refobj_path; 1862 const char *name; 1863 bool nodeflib, objgiven; 1864 1865 objgiven = refobj != NULL; 1866 1867 if (libmap_disable || !objgiven || 1868 (name = lm_find(refobj->path, xname)) == NULL) 1869 name = xname; 1870 1871 if (strchr(name, '/') != NULL) { /* Hard coded pathname */ 1872 if (name[0] != '/' && !trust) { 1873 _rtld_error("Absolute pathname required " 1874 "for shared object \"%s\"", name); 1875 return (NULL); 1876 } 1877 return (origin_subst(__DECONST(Obj_Entry *, refobj), 1878 __DECONST(char *, name))); 1879 } 1880 1881 dbg(" Searching for \"%s\"", name); 1882 refobj_path = objgiven ? refobj->path : NULL; 1883 1884 /* 1885 * If refobj->rpath != NULL, then refobj->runpath is NULL. Fall 1886 * back to pre-conforming behaviour if user requested so with 1887 * LD_LIBRARY_PATH_RPATH environment variable and ignore -z 1888 * nodeflib. 1889 */ 1890 if (objgiven && refobj->rpath != NULL && ld_library_path_rpath) { 1891 pathname = search_library_path(name, ld_library_path, 1892 refobj_path, fdp); 1893 if (pathname != NULL) 1894 return (pathname); 1895 if (refobj != NULL) { 1896 pathname = search_library_path(name, refobj->rpath, 1897 refobj_path, fdp); 1898 if (pathname != NULL) 1899 return (pathname); 1900 } 1901 pathname = search_library_pathfds(name, ld_library_dirs, fdp); 1902 if (pathname != NULL) 1903 return (pathname); 1904 pathname = search_library_path(name, gethints(false), 1905 refobj_path, fdp); 1906 if (pathname != NULL) 1907 return (pathname); 1908 pathname = search_library_path(name, ld_standard_library_path, 1909 refobj_path, fdp); 1910 if (pathname != NULL) 1911 return (pathname); 1912 } else { 1913 nodeflib = objgiven ? refobj->z_nodeflib : false; 1914 if (objgiven) { 1915 pathname = search_library_path(name, refobj->rpath, 1916 refobj->path, fdp); 1917 if (pathname != NULL) 1918 return (pathname); 1919 } 1920 if (objgiven && refobj->runpath == NULL && refobj != obj_main) { 1921 pathname = search_library_path(name, obj_main->rpath, 1922 refobj_path, fdp); 1923 if (pathname != NULL) 1924 return (pathname); 1925 } 1926 pathname = search_library_path(name, ld_library_path, 1927 refobj_path, fdp); 1928 if (pathname != NULL) 1929 return (pathname); 1930 if (objgiven) { 1931 pathname = search_library_path(name, refobj->runpath, 1932 refobj_path, fdp); 1933 if (pathname != NULL) 1934 return (pathname); 1935 } 1936 pathname = search_library_pathfds(name, ld_library_dirs, fdp); 1937 if (pathname != NULL) 1938 return (pathname); 1939 pathname = search_library_path(name, gethints(nodeflib), 1940 refobj_path, fdp); 1941 if (pathname != NULL) 1942 return (pathname); 1943 if (objgiven && !nodeflib) { 1944 pathname = search_library_path(name, 1945 ld_standard_library_path, refobj_path, fdp); 1946 if (pathname != NULL) 1947 return (pathname); 1948 } 1949 } 1950 1951 if (objgiven && refobj->path != NULL) { 1952 _rtld_error("Shared object \"%s\" not found, " 1953 "required by \"%s\"", name, basename(refobj->path)); 1954 } else { 1955 _rtld_error("Shared object \"%s\" not found", name); 1956 } 1957 return (NULL); 1958 } 1959 1960 /* 1961 * Given a symbol number in a referencing object, find the corresponding 1962 * definition of the symbol. Returns a pointer to the symbol, or NULL if 1963 * no definition was found. Returns a pointer to the Obj_Entry of the 1964 * defining object via the reference parameter DEFOBJ_OUT. 1965 */ 1966 const Elf_Sym * 1967 find_symdef(unsigned long symnum, const Obj_Entry *refobj, 1968 const Obj_Entry **defobj_out, int flags, SymCache *cache, 1969 RtldLockState *lockstate) 1970 { 1971 const Elf_Sym *ref; 1972 const Elf_Sym *def; 1973 const Obj_Entry *defobj; 1974 const Ver_Entry *ve; 1975 SymLook req; 1976 const char *name; 1977 int res; 1978 1979 /* 1980 * If we have already found this symbol, get the information from 1981 * the cache. 1982 */ 1983 if (symnum >= refobj->dynsymcount) 1984 return (NULL); /* Bad object */ 1985 if (cache != NULL && cache[symnum].sym != NULL) { 1986 *defobj_out = cache[symnum].obj; 1987 return (cache[symnum].sym); 1988 } 1989 1990 ref = refobj->symtab + symnum; 1991 name = refobj->strtab + ref->st_name; 1992 def = NULL; 1993 defobj = NULL; 1994 ve = NULL; 1995 1996 /* 1997 * We don't have to do a full scale lookup if the symbol is local. 1998 * We know it will bind to the instance in this load module; to 1999 * which we already have a pointer (ie ref). By not doing a lookup, 2000 * we not only improve performance, but it also avoids unresolvable 2001 * symbols when local symbols are not in the hash table. This has 2002 * been seen with the ia64 toolchain. 2003 */ 2004 if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) { 2005 if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) { 2006 _rtld_error("%s: Bogus symbol table entry %lu", refobj->path, 2007 symnum); 2008 } 2009 symlook_init(&req, name); 2010 req.flags = flags; 2011 ve = req.ventry = fetch_ventry(refobj, symnum); 2012 req.lockstate = lockstate; 2013 res = symlook_default(&req, refobj); 2014 if (res == 0) { 2015 def = req.sym_out; 2016 defobj = req.defobj_out; 2017 } 2018 } else { 2019 def = ref; 2020 defobj = refobj; 2021 } 2022 2023 /* 2024 * If we found no definition and the reference is weak, treat the 2025 * symbol as having the value zero. 2026 */ 2027 if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) { 2028 def = &sym_zero; 2029 defobj = obj_main; 2030 } 2031 2032 if (def != NULL) { 2033 *defobj_out = defobj; 2034 /* Record the information in the cache to avoid subsequent lookups. */ 2035 if (cache != NULL) { 2036 cache[symnum].sym = def; 2037 cache[symnum].obj = defobj; 2038 } 2039 } else { 2040 if (refobj != &obj_rtld) 2041 _rtld_error("%s: Undefined symbol \"%s%s%s\"", refobj->path, name, 2042 ve != NULL ? "@" : "", ve != NULL ? ve->name : ""); 2043 } 2044 return (def); 2045 } 2046 2047 /* 2048 * Return the search path from the ldconfig hints file, reading it if 2049 * necessary. If nostdlib is true, then the default search paths are 2050 * not added to result. 2051 * 2052 * Returns NULL if there are problems with the hints file, 2053 * or if the search path there is empty. 2054 */ 2055 static const char * 2056 gethints(bool nostdlib) 2057 { 2058 static char *filtered_path; 2059 static const char *hints; 2060 static struct elfhints_hdr hdr; 2061 struct fill_search_info_args sargs, hargs; 2062 struct dl_serinfo smeta, hmeta, *SLPinfo, *hintinfo; 2063 struct dl_serpath *SLPpath, *hintpath; 2064 char *p; 2065 struct stat hint_stat; 2066 unsigned int SLPndx, hintndx, fndx, fcount; 2067 int fd; 2068 size_t flen; 2069 uint32_t dl; 2070 bool skip; 2071 2072 /* First call, read the hints file */ 2073 if (hints == NULL) { 2074 /* Keep from trying again in case the hints file is bad. */ 2075 hints = ""; 2076 2077 if ((fd = open(ld_elf_hints_path, O_RDONLY | O_CLOEXEC)) == -1) 2078 return (NULL); 2079 2080 /* 2081 * Check of hdr.dirlistlen value against type limit 2082 * intends to pacify static analyzers. Further 2083 * paranoia leads to checks that dirlist is fully 2084 * contained in the file range. 2085 */ 2086 if (read(fd, &hdr, sizeof hdr) != sizeof hdr || 2087 hdr.magic != ELFHINTS_MAGIC || 2088 hdr.version != 1 || hdr.dirlistlen > UINT_MAX / 2 || 2089 fstat(fd, &hint_stat) == -1) { 2090 cleanup1: 2091 close(fd); 2092 hdr.dirlistlen = 0; 2093 return (NULL); 2094 } 2095 dl = hdr.strtab; 2096 if (dl + hdr.dirlist < dl) 2097 goto cleanup1; 2098 dl += hdr.dirlist; 2099 if (dl + hdr.dirlistlen < dl) 2100 goto cleanup1; 2101 dl += hdr.dirlistlen; 2102 if (dl > hint_stat.st_size) 2103 goto cleanup1; 2104 p = xmalloc(hdr.dirlistlen + 1); 2105 if (pread(fd, p, hdr.dirlistlen + 1, 2106 hdr.strtab + hdr.dirlist) != (ssize_t)hdr.dirlistlen + 1 || 2107 p[hdr.dirlistlen] != '\0') { 2108 free(p); 2109 goto cleanup1; 2110 } 2111 hints = p; 2112 close(fd); 2113 } 2114 2115 /* 2116 * If caller agreed to receive list which includes the default 2117 * paths, we are done. Otherwise, if we still did not 2118 * calculated filtered result, do it now. 2119 */ 2120 if (!nostdlib) 2121 return (hints[0] != '\0' ? hints : NULL); 2122 if (filtered_path != NULL) 2123 goto filt_ret; 2124 2125 /* 2126 * Obtain the list of all configured search paths, and the 2127 * list of the default paths. 2128 * 2129 * First estimate the size of the results. 2130 */ 2131 smeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 2132 smeta.dls_cnt = 0; 2133 hmeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 2134 hmeta.dls_cnt = 0; 2135 2136 sargs.request = RTLD_DI_SERINFOSIZE; 2137 sargs.serinfo = &smeta; 2138 hargs.request = RTLD_DI_SERINFOSIZE; 2139 hargs.serinfo = &hmeta; 2140 2141 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 2142 &sargs); 2143 path_enumerate(hints, fill_search_info, NULL, &hargs); 2144 2145 SLPinfo = xmalloc(smeta.dls_size); 2146 hintinfo = xmalloc(hmeta.dls_size); 2147 2148 /* 2149 * Next fetch both sets of paths. 2150 */ 2151 sargs.request = RTLD_DI_SERINFO; 2152 sargs.serinfo = SLPinfo; 2153 sargs.serpath = &SLPinfo->dls_serpath[0]; 2154 sargs.strspace = (char *)&SLPinfo->dls_serpath[smeta.dls_cnt]; 2155 2156 hargs.request = RTLD_DI_SERINFO; 2157 hargs.serinfo = hintinfo; 2158 hargs.serpath = &hintinfo->dls_serpath[0]; 2159 hargs.strspace = (char *)&hintinfo->dls_serpath[hmeta.dls_cnt]; 2160 2161 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 2162 &sargs); 2163 path_enumerate(hints, fill_search_info, NULL, &hargs); 2164 2165 /* 2166 * Now calculate the difference between two sets, by excluding 2167 * standard paths from the full set. 2168 */ 2169 fndx = 0; 2170 fcount = 0; 2171 filtered_path = xmalloc(hdr.dirlistlen + 1); 2172 hintpath = &hintinfo->dls_serpath[0]; 2173 for (hintndx = 0; hintndx < hmeta.dls_cnt; hintndx++, hintpath++) { 2174 skip = false; 2175 SLPpath = &SLPinfo->dls_serpath[0]; 2176 /* 2177 * Check each standard path against current. 2178 */ 2179 for (SLPndx = 0; SLPndx < smeta.dls_cnt; SLPndx++, SLPpath++) { 2180 /* matched, skip the path */ 2181 if (!strcmp(hintpath->dls_name, SLPpath->dls_name)) { 2182 skip = true; 2183 break; 2184 } 2185 } 2186 if (skip) 2187 continue; 2188 /* 2189 * Not matched against any standard path, add the path 2190 * to result. Separate consequtive paths with ':'. 2191 */ 2192 if (fcount > 0) { 2193 filtered_path[fndx] = ':'; 2194 fndx++; 2195 } 2196 fcount++; 2197 flen = strlen(hintpath->dls_name); 2198 strncpy((filtered_path + fndx), hintpath->dls_name, flen); 2199 fndx += flen; 2200 } 2201 filtered_path[fndx] = '\0'; 2202 2203 free(SLPinfo); 2204 free(hintinfo); 2205 2206 filt_ret: 2207 return (filtered_path[0] != '\0' ? filtered_path : NULL); 2208 } 2209 2210 static void 2211 init_dag(Obj_Entry *root) 2212 { 2213 const Needed_Entry *needed; 2214 const Objlist_Entry *elm; 2215 DoneList donelist; 2216 2217 if (root->dag_inited) 2218 return; 2219 donelist_init(&donelist); 2220 2221 /* Root object belongs to own DAG. */ 2222 objlist_push_tail(&root->dldags, root); 2223 objlist_push_tail(&root->dagmembers, root); 2224 donelist_check(&donelist, root); 2225 2226 /* 2227 * Add dependencies of root object to DAG in breadth order 2228 * by exploiting the fact that each new object get added 2229 * to the tail of the dagmembers list. 2230 */ 2231 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2232 for (needed = elm->obj->needed; needed != NULL; needed = needed->next) { 2233 if (needed->obj == NULL || donelist_check(&donelist, needed->obj)) 2234 continue; 2235 objlist_push_tail(&needed->obj->dldags, root); 2236 objlist_push_tail(&root->dagmembers, needed->obj); 2237 } 2238 } 2239 root->dag_inited = true; 2240 } 2241 2242 static void 2243 init_marker(Obj_Entry *marker) 2244 { 2245 2246 bzero(marker, sizeof(*marker)); 2247 marker->marker = true; 2248 } 2249 2250 Obj_Entry * 2251 globallist_curr(const Obj_Entry *obj) 2252 { 2253 2254 for (;;) { 2255 if (obj == NULL) 2256 return (NULL); 2257 if (!obj->marker) 2258 return (__DECONST(Obj_Entry *, obj)); 2259 obj = TAILQ_PREV(obj, obj_entry_q, next); 2260 } 2261 } 2262 2263 Obj_Entry * 2264 globallist_next(const Obj_Entry *obj) 2265 { 2266 2267 for (;;) { 2268 obj = TAILQ_NEXT(obj, next); 2269 if (obj == NULL) 2270 return (NULL); 2271 if (!obj->marker) 2272 return (__DECONST(Obj_Entry *, obj)); 2273 } 2274 } 2275 2276 /* Prevent the object from being unmapped while the bind lock is dropped. */ 2277 static void 2278 hold_object(Obj_Entry *obj) 2279 { 2280 2281 obj->holdcount++; 2282 } 2283 2284 static void 2285 unhold_object(Obj_Entry *obj) 2286 { 2287 2288 assert(obj->holdcount > 0); 2289 if (--obj->holdcount == 0 && obj->unholdfree) 2290 release_object(obj); 2291 } 2292 2293 static void 2294 process_z(Obj_Entry *root) 2295 { 2296 const Objlist_Entry *elm; 2297 Obj_Entry *obj; 2298 2299 /* 2300 * Walk over object DAG and process every dependent object 2301 * that is marked as DF_1_NODELETE or DF_1_GLOBAL. They need 2302 * to grow their own DAG. 2303 * 2304 * For DF_1_GLOBAL, DAG is required for symbol lookups in 2305 * symlook_global() to work. 2306 * 2307 * For DF_1_NODELETE, the DAG should have its reference upped. 2308 */ 2309 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2310 obj = elm->obj; 2311 if (obj == NULL) 2312 continue; 2313 if (obj->z_nodelete && !obj->ref_nodel) { 2314 dbg("obj %s -z nodelete", obj->path); 2315 init_dag(obj); 2316 ref_dag(obj); 2317 obj->ref_nodel = true; 2318 } 2319 if (obj->z_global && objlist_find(&list_global, obj) == NULL) { 2320 dbg("obj %s -z global", obj->path); 2321 objlist_push_tail(&list_global, obj); 2322 init_dag(obj); 2323 } 2324 } 2325 } 2326 2327 static void 2328 parse_rtld_phdr(Obj_Entry *obj) 2329 { 2330 const Elf_Phdr *ph; 2331 Elf_Addr note_start, note_end; 2332 2333 obj->stack_flags = PF_X | PF_R | PF_W; 2334 for (ph = obj->phdr; (const char *)ph < (const char *)obj->phdr + 2335 obj->phsize; ph++) { 2336 switch (ph->p_type) { 2337 case PT_GNU_STACK: 2338 obj->stack_flags = ph->p_flags; 2339 break; 2340 case PT_GNU_RELRO: 2341 obj->relro_page = obj->relocbase + 2342 rtld_trunc_page(ph->p_vaddr); 2343 obj->relro_size = rtld_round_page(ph->p_memsz); 2344 break; 2345 case PT_NOTE: 2346 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; 2347 note_end = note_start + ph->p_filesz; 2348 digest_notes(obj, note_start, note_end); 2349 break; 2350 } 2351 } 2352 } 2353 2354 /* 2355 * Initialize the dynamic linker. The argument is the address at which 2356 * the dynamic linker has been mapped into memory. The primary task of 2357 * this function is to relocate the dynamic linker. 2358 */ 2359 static void 2360 init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info) 2361 { 2362 Obj_Entry objtmp; /* Temporary rtld object */ 2363 const Elf_Ehdr *ehdr; 2364 const Elf_Dyn *dyn_rpath; 2365 const Elf_Dyn *dyn_soname; 2366 const Elf_Dyn *dyn_runpath; 2367 2368 #ifdef RTLD_INIT_PAGESIZES_EARLY 2369 /* The page size is required by the dynamic memory allocator. */ 2370 init_pagesizes(aux_info); 2371 #endif 2372 2373 /* 2374 * Conjure up an Obj_Entry structure for the dynamic linker. 2375 * 2376 * The "path" member can't be initialized yet because string constants 2377 * cannot yet be accessed. Below we will set it correctly. 2378 */ 2379 memset(&objtmp, 0, sizeof(objtmp)); 2380 objtmp.path = NULL; 2381 objtmp.rtld = true; 2382 objtmp.mapbase = mapbase; 2383 #ifdef PIC 2384 objtmp.relocbase = mapbase; 2385 #endif 2386 2387 objtmp.dynamic = rtld_dynamic(&objtmp); 2388 digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname, &dyn_runpath); 2389 assert(objtmp.needed == NULL); 2390 assert(!objtmp.textrel); 2391 /* 2392 * Temporarily put the dynamic linker entry into the object list, so 2393 * that symbols can be found. 2394 */ 2395 relocate_objects(&objtmp, true, &objtmp, 0, NULL); 2396 2397 ehdr = (Elf_Ehdr *)mapbase; 2398 objtmp.phdr = (Elf_Phdr *)((char *)mapbase + ehdr->e_phoff); 2399 objtmp.phsize = ehdr->e_phnum * sizeof(objtmp.phdr[0]); 2400 2401 /* Initialize the object list. */ 2402 TAILQ_INIT(&obj_list); 2403 2404 /* Now that non-local variables can be accesses, copy out obj_rtld. */ 2405 memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld)); 2406 2407 #ifndef RTLD_INIT_PAGESIZES_EARLY 2408 /* The page size is required by the dynamic memory allocator. */ 2409 init_pagesizes(aux_info); 2410 #endif 2411 2412 if (aux_info[AT_OSRELDATE] != NULL) 2413 osreldate = aux_info[AT_OSRELDATE]->a_un.a_val; 2414 2415 digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname, dyn_runpath); 2416 2417 /* Replace the path with a dynamically allocated copy. */ 2418 obj_rtld.path = xstrdup(ld_path_rtld); 2419 2420 parse_rtld_phdr(&obj_rtld); 2421 if (obj_enforce_relro(&obj_rtld) == -1) 2422 rtld_die(); 2423 2424 r_debug.r_version = R_DEBUG_VERSION; 2425 r_debug.r_brk = r_debug_state; 2426 r_debug.r_state = RT_CONSISTENT; 2427 r_debug.r_ldbase = obj_rtld.relocbase; 2428 } 2429 2430 /* 2431 * Retrieve the array of supported page sizes. The kernel provides the page 2432 * sizes in increasing order. 2433 */ 2434 static void 2435 init_pagesizes(Elf_Auxinfo **aux_info) 2436 { 2437 static size_t psa[MAXPAGESIZES]; 2438 int mib[2]; 2439 size_t len, size; 2440 2441 if (aux_info[AT_PAGESIZES] != NULL && aux_info[AT_PAGESIZESLEN] != 2442 NULL) { 2443 size = aux_info[AT_PAGESIZESLEN]->a_un.a_val; 2444 pagesizes = aux_info[AT_PAGESIZES]->a_un.a_ptr; 2445 } else { 2446 len = 2; 2447 if (sysctlnametomib("hw.pagesizes", mib, &len) == 0) 2448 size = sizeof(psa); 2449 else { 2450 /* As a fallback, retrieve the base page size. */ 2451 size = sizeof(psa[0]); 2452 if (aux_info[AT_PAGESZ] != NULL) { 2453 psa[0] = aux_info[AT_PAGESZ]->a_un.a_val; 2454 goto psa_filled; 2455 } else { 2456 mib[0] = CTL_HW; 2457 mib[1] = HW_PAGESIZE; 2458 len = 2; 2459 } 2460 } 2461 if (sysctl(mib, len, psa, &size, NULL, 0) == -1) { 2462 _rtld_error("sysctl for hw.pagesize(s) failed"); 2463 rtld_die(); 2464 } 2465 psa_filled: 2466 pagesizes = psa; 2467 } 2468 npagesizes = size / sizeof(pagesizes[0]); 2469 /* Discard any invalid entries at the end of the array. */ 2470 while (npagesizes > 0 && pagesizes[npagesizes - 1] == 0) 2471 npagesizes--; 2472 2473 page_size = pagesizes[0]; 2474 } 2475 2476 /* 2477 * Add the init functions from a needed object list (and its recursive 2478 * needed objects) to "list". This is not used directly; it is a helper 2479 * function for initlist_add_objects(). The write lock must be held 2480 * when this function is called. 2481 */ 2482 static void 2483 initlist_add_neededs(Needed_Entry *needed, Objlist *list) 2484 { 2485 /* Recursively process the successor needed objects. */ 2486 if (needed->next != NULL) 2487 initlist_add_neededs(needed->next, list); 2488 2489 /* Process the current needed object. */ 2490 if (needed->obj != NULL) 2491 initlist_add_objects(needed->obj, needed->obj, list); 2492 } 2493 2494 /* 2495 * Scan all of the DAGs rooted in the range of objects from "obj" to 2496 * "tail" and add their init functions to "list". This recurses over 2497 * the DAGs and ensure the proper init ordering such that each object's 2498 * needed libraries are initialized before the object itself. At the 2499 * same time, this function adds the objects to the global finalization 2500 * list "list_fini" in the opposite order. The write lock must be 2501 * held when this function is called. 2502 */ 2503 static void 2504 initlist_add_objects(Obj_Entry *obj, Obj_Entry *tail, Objlist *list) 2505 { 2506 Obj_Entry *nobj; 2507 2508 if (obj->init_scanned || obj->init_done) 2509 return; 2510 obj->init_scanned = true; 2511 2512 /* Recursively process the successor objects. */ 2513 nobj = globallist_next(obj); 2514 if (nobj != NULL && obj != tail) 2515 initlist_add_objects(nobj, tail, list); 2516 2517 /* Recursively process the needed objects. */ 2518 if (obj->needed != NULL) 2519 initlist_add_neededs(obj->needed, list); 2520 if (obj->needed_filtees != NULL) 2521 initlist_add_neededs(obj->needed_filtees, list); 2522 if (obj->needed_aux_filtees != NULL) 2523 initlist_add_neededs(obj->needed_aux_filtees, list); 2524 2525 /* Add the object to the init list. */ 2526 objlist_push_tail(list, obj); 2527 2528 /* Add the object to the global fini list in the reverse order. */ 2529 if ((obj->fini != (Elf_Addr)NULL || obj->fini_array != (Elf_Addr)NULL) 2530 && !obj->on_fini_list) { 2531 objlist_push_head(&list_fini, obj); 2532 obj->on_fini_list = true; 2533 } 2534 } 2535 2536 static void 2537 free_needed_filtees(Needed_Entry *n, RtldLockState *lockstate) 2538 { 2539 Needed_Entry *needed, *needed1; 2540 2541 for (needed = n; needed != NULL; needed = needed->next) { 2542 if (needed->obj != NULL) { 2543 dlclose_locked(needed->obj, lockstate); 2544 needed->obj = NULL; 2545 } 2546 } 2547 for (needed = n; needed != NULL; needed = needed1) { 2548 needed1 = needed->next; 2549 free(needed); 2550 } 2551 } 2552 2553 static void 2554 unload_filtees(Obj_Entry *obj, RtldLockState *lockstate) 2555 { 2556 2557 free_needed_filtees(obj->needed_filtees, lockstate); 2558 obj->needed_filtees = NULL; 2559 free_needed_filtees(obj->needed_aux_filtees, lockstate); 2560 obj->needed_aux_filtees = NULL; 2561 obj->filtees_loaded = false; 2562 } 2563 2564 static void 2565 load_filtee1(Obj_Entry *obj, Needed_Entry *needed, int flags, 2566 RtldLockState *lockstate) 2567 { 2568 2569 for (; needed != NULL; needed = needed->next) { 2570 needed->obj = dlopen_object(obj->strtab + needed->name, -1, obj, 2571 flags, ((ld_loadfltr || obj->z_loadfltr) ? RTLD_NOW : RTLD_LAZY) | 2572 RTLD_LOCAL, lockstate); 2573 } 2574 } 2575 2576 static void 2577 load_filtees(Obj_Entry *obj, int flags, RtldLockState *lockstate) 2578 { 2579 2580 lock_restart_for_upgrade(lockstate); 2581 if (!obj->filtees_loaded) { 2582 load_filtee1(obj, obj->needed_filtees, flags, lockstate); 2583 load_filtee1(obj, obj->needed_aux_filtees, flags, lockstate); 2584 obj->filtees_loaded = true; 2585 } 2586 } 2587 2588 static int 2589 process_needed(Obj_Entry *obj, Needed_Entry *needed, int flags) 2590 { 2591 Obj_Entry *obj1; 2592 2593 for (; needed != NULL; needed = needed->next) { 2594 obj1 = needed->obj = load_object(obj->strtab + needed->name, -1, obj, 2595 flags & ~RTLD_LO_NOLOAD); 2596 if (obj1 == NULL && !ld_tracing && (flags & RTLD_LO_FILTEES) == 0) 2597 return (-1); 2598 } 2599 return (0); 2600 } 2601 2602 /* 2603 * Given a shared object, traverse its list of needed objects, and load 2604 * each of them. Returns 0 on success. Generates an error message and 2605 * returns -1 on failure. 2606 */ 2607 static int 2608 load_needed_objects(Obj_Entry *first, int flags) 2609 { 2610 Obj_Entry *obj; 2611 2612 for (obj = first; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 2613 if (obj->marker) 2614 continue; 2615 if (process_needed(obj, obj->needed, flags) == -1) 2616 return (-1); 2617 } 2618 return (0); 2619 } 2620 2621 static int 2622 load_preload_objects(const char *penv, bool isfd) 2623 { 2624 Obj_Entry *obj; 2625 const char *name; 2626 size_t len; 2627 char savech, *p, *psave; 2628 int fd; 2629 static const char delim[] = " \t:;"; 2630 2631 if (penv == NULL) 2632 return (0); 2633 2634 p = psave = xstrdup(penv); 2635 p += strspn(p, delim); 2636 while (*p != '\0') { 2637 len = strcspn(p, delim); 2638 2639 savech = p[len]; 2640 p[len] = '\0'; 2641 if (isfd) { 2642 name = NULL; 2643 fd = parse_integer(p); 2644 if (fd == -1) { 2645 free(psave); 2646 return (-1); 2647 } 2648 } else { 2649 name = p; 2650 fd = -1; 2651 } 2652 2653 obj = load_object(name, fd, NULL, 0); 2654 if (obj == NULL) { 2655 free(psave); 2656 return (-1); /* XXX - cleanup */ 2657 } 2658 obj->z_interpose = true; 2659 p[len] = savech; 2660 p += len; 2661 p += strspn(p, delim); 2662 } 2663 LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL); 2664 2665 free(psave); 2666 return (0); 2667 } 2668 2669 static const char * 2670 printable_path(const char *path) 2671 { 2672 2673 return (path == NULL ? "<unknown>" : path); 2674 } 2675 2676 /* 2677 * Load a shared object into memory, if it is not already loaded. The 2678 * object may be specified by name or by user-supplied file descriptor 2679 * fd_u. In the later case, the fd_u descriptor is not closed, but its 2680 * duplicate is. 2681 * 2682 * Returns a pointer to the Obj_Entry for the object. Returns NULL 2683 * on failure. 2684 */ 2685 static Obj_Entry * 2686 load_object(const char *name, int fd_u, const Obj_Entry *refobj, int flags) 2687 { 2688 Obj_Entry *obj; 2689 int fd; 2690 struct stat sb; 2691 char *path; 2692 2693 fd = -1; 2694 if (name != NULL) { 2695 TAILQ_FOREACH(obj, &obj_list, next) { 2696 if (obj->marker || obj->doomed) 2697 continue; 2698 if (object_match_name(obj, name)) 2699 return (obj); 2700 } 2701 2702 path = find_library(name, refobj, &fd); 2703 if (path == NULL) 2704 return (NULL); 2705 } else 2706 path = NULL; 2707 2708 if (fd >= 0) { 2709 /* 2710 * search_library_pathfds() opens a fresh file descriptor for the 2711 * library, so there is no need to dup(). 2712 */ 2713 } else if (fd_u == -1) { 2714 /* 2715 * If we didn't find a match by pathname, or the name is not 2716 * supplied, open the file and check again by device and inode. 2717 * This avoids false mismatches caused by multiple links or ".." 2718 * in pathnames. 2719 * 2720 * To avoid a race, we open the file and use fstat() rather than 2721 * using stat(). 2722 */ 2723 if ((fd = open(path, O_RDONLY | O_CLOEXEC | O_VERIFY)) == -1) { 2724 _rtld_error("Cannot open \"%s\"", path); 2725 free(path); 2726 return (NULL); 2727 } 2728 } else { 2729 fd = fcntl(fd_u, F_DUPFD_CLOEXEC, 0); 2730 if (fd == -1) { 2731 _rtld_error("Cannot dup fd"); 2732 free(path); 2733 return (NULL); 2734 } 2735 } 2736 if (fstat(fd, &sb) == -1) { 2737 _rtld_error("Cannot fstat \"%s\"", printable_path(path)); 2738 close(fd); 2739 free(path); 2740 return (NULL); 2741 } 2742 TAILQ_FOREACH(obj, &obj_list, next) { 2743 if (obj->marker || obj->doomed) 2744 continue; 2745 if (obj->ino == sb.st_ino && obj->dev == sb.st_dev) 2746 break; 2747 } 2748 if (obj != NULL && name != NULL) { 2749 object_add_name(obj, name); 2750 free(path); 2751 close(fd); 2752 return (obj); 2753 } 2754 if (flags & RTLD_LO_NOLOAD) { 2755 free(path); 2756 close(fd); 2757 return (NULL); 2758 } 2759 2760 /* First use of this object, so we must map it in */ 2761 obj = do_load_object(fd, name, path, &sb, flags); 2762 if (obj == NULL) 2763 free(path); 2764 close(fd); 2765 2766 return (obj); 2767 } 2768 2769 static Obj_Entry * 2770 do_load_object(int fd, const char *name, char *path, struct stat *sbp, 2771 int flags) 2772 { 2773 Obj_Entry *obj; 2774 struct statfs fs; 2775 2776 /* 2777 * First, make sure that environment variables haven't been 2778 * used to circumvent the noexec flag on a filesystem. 2779 * We ignore fstatfs(2) failures, since fd might reference 2780 * not a file, e.g. shmfd. 2781 */ 2782 if (dangerous_ld_env && fstatfs(fd, &fs) == 0 && 2783 (fs.f_flags & MNT_NOEXEC) != 0) { 2784 _rtld_error("Cannot execute objects on %s", fs.f_mntonname); 2785 return (NULL); 2786 } 2787 2788 dbg("loading \"%s\"", printable_path(path)); 2789 obj = map_object(fd, printable_path(path), sbp); 2790 if (obj == NULL) 2791 return (NULL); 2792 2793 /* 2794 * If DT_SONAME is present in the object, digest_dynamic2 already 2795 * added it to the object names. 2796 */ 2797 if (name != NULL) 2798 object_add_name(obj, name); 2799 obj->path = path; 2800 if (!digest_dynamic(obj, 0)) 2801 goto errp; 2802 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", obj->path, 2803 obj->valid_hash_sysv, obj->valid_hash_gnu, obj->dynsymcount); 2804 if (obj->z_pie && (flags & RTLD_LO_TRACE) == 0) { 2805 dbg("refusing to load PIE executable \"%s\"", obj->path); 2806 _rtld_error("Cannot load PIE binary %s as DSO", obj->path); 2807 goto errp; 2808 } 2809 if (obj->z_noopen && (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) == 2810 RTLD_LO_DLOPEN) { 2811 dbg("refusing to load non-loadable \"%s\"", obj->path); 2812 _rtld_error("Cannot dlopen non-loadable %s", obj->path); 2813 goto errp; 2814 } 2815 2816 obj->dlopened = (flags & RTLD_LO_DLOPEN) != 0; 2817 TAILQ_INSERT_TAIL(&obj_list, obj, next); 2818 obj_count++; 2819 obj_loads++; 2820 linkmap_add(obj); /* for GDB & dlinfo() */ 2821 max_stack_flags |= obj->stack_flags; 2822 2823 dbg(" %p .. %p: %s", obj->mapbase, 2824 obj->mapbase + obj->mapsize - 1, obj->path); 2825 if (obj->textrel) 2826 dbg(" WARNING: %s has impure text", obj->path); 2827 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 2828 obj->path); 2829 2830 return (obj); 2831 2832 errp: 2833 munmap(obj->mapbase, obj->mapsize); 2834 obj_free(obj); 2835 return (NULL); 2836 } 2837 2838 static int 2839 load_kpreload(const void *addr) 2840 { 2841 Obj_Entry *obj; 2842 const Elf_Ehdr *ehdr; 2843 const Elf_Phdr *phdr, *phlimit, *phdyn, *seg0, *segn; 2844 static const char kname[] = "[vdso]"; 2845 2846 ehdr = addr; 2847 if (!check_elf_headers(ehdr, "kpreload")) 2848 return (-1); 2849 obj = obj_new(); 2850 phdr = (const Elf_Phdr *)((const char *)addr + ehdr->e_phoff); 2851 obj->phdr = phdr; 2852 obj->phsize = ehdr->e_phnum * sizeof(*phdr); 2853 phlimit = phdr + ehdr->e_phnum; 2854 seg0 = segn = NULL; 2855 2856 for (; phdr < phlimit; phdr++) { 2857 switch (phdr->p_type) { 2858 case PT_DYNAMIC: 2859 phdyn = phdr; 2860 break; 2861 case PT_GNU_STACK: 2862 /* Absense of PT_GNU_STACK implies stack_flags == 0. */ 2863 obj->stack_flags = phdr->p_flags; 2864 break; 2865 case PT_LOAD: 2866 if (seg0 == NULL || seg0->p_vaddr > phdr->p_vaddr) 2867 seg0 = phdr; 2868 if (segn == NULL || segn->p_vaddr + segn->p_memsz < 2869 phdr->p_vaddr + phdr->p_memsz) 2870 segn = phdr; 2871 break; 2872 } 2873 } 2874 2875 obj->mapbase = __DECONST(caddr_t, addr); 2876 obj->mapsize = segn->p_vaddr + segn->p_memsz - (Elf_Addr)addr; 2877 obj->vaddrbase = 0; 2878 obj->relocbase = obj->mapbase; 2879 2880 object_add_name(obj, kname); 2881 obj->path = xstrdup(kname); 2882 obj->dynamic = (const Elf_Dyn *)(obj->relocbase + phdyn->p_vaddr); 2883 2884 if (!digest_dynamic(obj, 0)) { 2885 obj_free(obj); 2886 return (-1); 2887 } 2888 2889 /* 2890 * We assume that kernel-preloaded object does not need 2891 * relocation. It is currently written into read-only page, 2892 * handling relocations would mean we need to allocate at 2893 * least one additional page per AS. 2894 */ 2895 dbg("%s mapbase %p phdrs %p PT_LOAD phdr %p vaddr %p dynamic %p", 2896 obj->path, obj->mapbase, obj->phdr, seg0, 2897 obj->relocbase + seg0->p_vaddr, obj->dynamic); 2898 2899 TAILQ_INSERT_TAIL(&obj_list, obj, next); 2900 obj_count++; 2901 obj_loads++; 2902 linkmap_add(obj); /* for GDB & dlinfo() */ 2903 max_stack_flags |= obj->stack_flags; 2904 2905 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, 0, 0, obj->path); 2906 return (0); 2907 } 2908 2909 Obj_Entry * 2910 obj_from_addr(const void *addr) 2911 { 2912 Obj_Entry *obj; 2913 2914 TAILQ_FOREACH(obj, &obj_list, next) { 2915 if (obj->marker) 2916 continue; 2917 if (addr < (void *) obj->mapbase) 2918 continue; 2919 if (addr < (void *)(obj->mapbase + obj->mapsize)) 2920 return obj; 2921 } 2922 return (NULL); 2923 } 2924 2925 static void 2926 preinit_main(void) 2927 { 2928 Elf_Addr *preinit_addr; 2929 int index; 2930 2931 preinit_addr = (Elf_Addr *)obj_main->preinit_array; 2932 if (preinit_addr == NULL) 2933 return; 2934 2935 for (index = 0; index < obj_main->preinit_array_num; index++) { 2936 if (preinit_addr[index] != 0 && preinit_addr[index] != 1) { 2937 dbg("calling preinit function for %s at %p", obj_main->path, 2938 (void *)preinit_addr[index]); 2939 LD_UTRACE(UTRACE_INIT_CALL, obj_main, (void *)preinit_addr[index], 2940 0, 0, obj_main->path); 2941 call_init_pointer(obj_main, preinit_addr[index]); 2942 } 2943 } 2944 } 2945 2946 /* 2947 * Call the finalization functions for each of the objects in "list" 2948 * belonging to the DAG of "root" and referenced once. If NULL "root" 2949 * is specified, every finalization function will be called regardless 2950 * of the reference count and the list elements won't be freed. All of 2951 * the objects are expected to have non-NULL fini functions. 2952 */ 2953 static void 2954 objlist_call_fini(Objlist *list, Obj_Entry *root, RtldLockState *lockstate) 2955 { 2956 Objlist_Entry *elm; 2957 struct dlerror_save *saved_msg; 2958 Elf_Addr *fini_addr; 2959 int index; 2960 2961 assert(root == NULL || root->refcount == 1); 2962 2963 if (root != NULL) 2964 root->doomed = true; 2965 2966 /* 2967 * Preserve the current error message since a fini function might 2968 * call into the dynamic linker and overwrite it. 2969 */ 2970 saved_msg = errmsg_save(); 2971 do { 2972 STAILQ_FOREACH(elm, list, link) { 2973 if (root != NULL && (elm->obj->refcount != 1 || 2974 objlist_find(&root->dagmembers, elm->obj) == NULL)) 2975 continue; 2976 /* Remove object from fini list to prevent recursive invocation. */ 2977 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 2978 /* Ensure that new references cannot be acquired. */ 2979 elm->obj->doomed = true; 2980 2981 hold_object(elm->obj); 2982 lock_release(rtld_bind_lock, lockstate); 2983 /* 2984 * It is legal to have both DT_FINI and DT_FINI_ARRAY defined. 2985 * When this happens, DT_FINI_ARRAY is processed first. 2986 */ 2987 fini_addr = (Elf_Addr *)elm->obj->fini_array; 2988 if (fini_addr != NULL && elm->obj->fini_array_num > 0) { 2989 for (index = elm->obj->fini_array_num - 1; index >= 0; 2990 index--) { 2991 if (fini_addr[index] != 0 && fini_addr[index] != 1) { 2992 dbg("calling fini function for %s at %p", 2993 elm->obj->path, (void *)fini_addr[index]); 2994 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, 2995 (void *)fini_addr[index], 0, 0, elm->obj->path); 2996 call_initfini_pointer(elm->obj, fini_addr[index]); 2997 } 2998 } 2999 } 3000 if (elm->obj->fini != (Elf_Addr)NULL) { 3001 dbg("calling fini function for %s at %p", elm->obj->path, 3002 (void *)elm->obj->fini); 3003 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, (void *)elm->obj->fini, 3004 0, 0, elm->obj->path); 3005 call_initfini_pointer(elm->obj, elm->obj->fini); 3006 } 3007 wlock_acquire(rtld_bind_lock, lockstate); 3008 unhold_object(elm->obj); 3009 /* No need to free anything if process is going down. */ 3010 if (root != NULL) 3011 free(elm); 3012 /* 3013 * We must restart the list traversal after every fini call 3014 * because a dlclose() call from the fini function or from 3015 * another thread might have modified the reference counts. 3016 */ 3017 break; 3018 } 3019 } while (elm != NULL); 3020 errmsg_restore(saved_msg); 3021 } 3022 3023 /* 3024 * Call the initialization functions for each of the objects in 3025 * "list". All of the objects are expected to have non-NULL init 3026 * functions. 3027 */ 3028 static void 3029 objlist_call_init(Objlist *list, RtldLockState *lockstate) 3030 { 3031 Objlist_Entry *elm; 3032 Obj_Entry *obj; 3033 struct dlerror_save *saved_msg; 3034 Elf_Addr *init_addr; 3035 void (*reg)(void (*)(void)); 3036 int index; 3037 3038 /* 3039 * Clean init_scanned flag so that objects can be rechecked and 3040 * possibly initialized earlier if any of vectors called below 3041 * cause the change by using dlopen. 3042 */ 3043 TAILQ_FOREACH(obj, &obj_list, next) { 3044 if (obj->marker) 3045 continue; 3046 obj->init_scanned = false; 3047 } 3048 3049 /* 3050 * Preserve the current error message since an init function might 3051 * call into the dynamic linker and overwrite it. 3052 */ 3053 saved_msg = errmsg_save(); 3054 STAILQ_FOREACH(elm, list, link) { 3055 if (elm->obj->init_done) /* Initialized early. */ 3056 continue; 3057 /* 3058 * Race: other thread might try to use this object before current 3059 * one completes the initialization. Not much can be done here 3060 * without better locking. 3061 */ 3062 elm->obj->init_done = true; 3063 hold_object(elm->obj); 3064 reg = NULL; 3065 if (elm->obj == obj_main && obj_main->crt_no_init) { 3066 reg = (void (*)(void (*)(void)))get_program_var_addr( 3067 "__libc_atexit", lockstate); 3068 } 3069 lock_release(rtld_bind_lock, lockstate); 3070 if (reg != NULL) { 3071 reg(rtld_exit); 3072 rtld_exit_ptr = rtld_nop_exit; 3073 } 3074 3075 /* 3076 * It is legal to have both DT_INIT and DT_INIT_ARRAY defined. 3077 * When this happens, DT_INIT is processed first. 3078 */ 3079 if (elm->obj->init != (Elf_Addr)NULL) { 3080 dbg("calling init function for %s at %p", elm->obj->path, 3081 (void *)elm->obj->init); 3082 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, (void *)elm->obj->init, 3083 0, 0, elm->obj->path); 3084 call_init_pointer(elm->obj, elm->obj->init); 3085 } 3086 init_addr = (Elf_Addr *)elm->obj->init_array; 3087 if (init_addr != NULL) { 3088 for (index = 0; index < elm->obj->init_array_num; index++) { 3089 if (init_addr[index] != 0 && init_addr[index] != 1) { 3090 dbg("calling init function for %s at %p", elm->obj->path, 3091 (void *)init_addr[index]); 3092 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, 3093 (void *)init_addr[index], 0, 0, elm->obj->path); 3094 call_init_pointer(elm->obj, init_addr[index]); 3095 } 3096 } 3097 } 3098 wlock_acquire(rtld_bind_lock, lockstate); 3099 unhold_object(elm->obj); 3100 } 3101 errmsg_restore(saved_msg); 3102 } 3103 3104 static void 3105 objlist_clear(Objlist *list) 3106 { 3107 Objlist_Entry *elm; 3108 3109 while (!STAILQ_EMPTY(list)) { 3110 elm = STAILQ_FIRST(list); 3111 STAILQ_REMOVE_HEAD(list, link); 3112 free(elm); 3113 } 3114 } 3115 3116 static Objlist_Entry * 3117 objlist_find(Objlist *list, const Obj_Entry *obj) 3118 { 3119 Objlist_Entry *elm; 3120 3121 STAILQ_FOREACH(elm, list, link) 3122 if (elm->obj == obj) 3123 return elm; 3124 return (NULL); 3125 } 3126 3127 static void 3128 objlist_init(Objlist *list) 3129 { 3130 STAILQ_INIT(list); 3131 } 3132 3133 static void 3134 objlist_push_head(Objlist *list, Obj_Entry *obj) 3135 { 3136 Objlist_Entry *elm; 3137 3138 elm = NEW(Objlist_Entry); 3139 elm->obj = obj; 3140 STAILQ_INSERT_HEAD(list, elm, link); 3141 } 3142 3143 static void 3144 objlist_push_tail(Objlist *list, Obj_Entry *obj) 3145 { 3146 Objlist_Entry *elm; 3147 3148 elm = NEW(Objlist_Entry); 3149 elm->obj = obj; 3150 STAILQ_INSERT_TAIL(list, elm, link); 3151 } 3152 3153 static void 3154 objlist_put_after(Objlist *list, Obj_Entry *listobj, Obj_Entry *obj) 3155 { 3156 Objlist_Entry *elm, *listelm; 3157 3158 STAILQ_FOREACH(listelm, list, link) { 3159 if (listelm->obj == listobj) 3160 break; 3161 } 3162 elm = NEW(Objlist_Entry); 3163 elm->obj = obj; 3164 if (listelm != NULL) 3165 STAILQ_INSERT_AFTER(list, listelm, elm, link); 3166 else 3167 STAILQ_INSERT_TAIL(list, elm, link); 3168 } 3169 3170 static void 3171 objlist_remove(Objlist *list, Obj_Entry *obj) 3172 { 3173 Objlist_Entry *elm; 3174 3175 if ((elm = objlist_find(list, obj)) != NULL) { 3176 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 3177 free(elm); 3178 } 3179 } 3180 3181 /* 3182 * Relocate dag rooted in the specified object. 3183 * Returns 0 on success, or -1 on failure. 3184 */ 3185 3186 static int 3187 relocate_object_dag(Obj_Entry *root, bool bind_now, Obj_Entry *rtldobj, 3188 int flags, RtldLockState *lockstate) 3189 { 3190 Objlist_Entry *elm; 3191 int error; 3192 3193 error = 0; 3194 STAILQ_FOREACH(elm, &root->dagmembers, link) { 3195 error = relocate_object(elm->obj, bind_now, rtldobj, flags, 3196 lockstate); 3197 if (error == -1) 3198 break; 3199 } 3200 return (error); 3201 } 3202 3203 /* 3204 * Prepare for, or clean after, relocating an object marked with 3205 * DT_TEXTREL or DF_TEXTREL. Before relocating, all read-only 3206 * segments are remapped read-write. After relocations are done, the 3207 * segment's permissions are returned back to the modes specified in 3208 * the phdrs. If any relocation happened, or always for wired 3209 * program, COW is triggered. 3210 */ 3211 static int 3212 reloc_textrel_prot(Obj_Entry *obj, bool before) 3213 { 3214 const Elf_Phdr *ph; 3215 void *base; 3216 size_t l, sz; 3217 int prot; 3218 3219 for (l = obj->phsize / sizeof(*ph), ph = obj->phdr; l > 0; 3220 l--, ph++) { 3221 if (ph->p_type != PT_LOAD || (ph->p_flags & PF_W) != 0) 3222 continue; 3223 base = obj->relocbase + rtld_trunc_page(ph->p_vaddr); 3224 sz = rtld_round_page(ph->p_vaddr + ph->p_filesz) - 3225 rtld_trunc_page(ph->p_vaddr); 3226 prot = before ? (PROT_READ | PROT_WRITE) : 3227 convert_prot(ph->p_flags); 3228 if (mprotect(base, sz, prot) == -1) { 3229 _rtld_error("%s: Cannot write-%sable text segment: %s", 3230 obj->path, before ? "en" : "dis", 3231 rtld_strerror(errno)); 3232 return (-1); 3233 } 3234 } 3235 return (0); 3236 } 3237 3238 /* Process RELR relative relocations. */ 3239 static void 3240 reloc_relr(Obj_Entry *obj) 3241 { 3242 const Elf_Relr *relr, *relrlim; 3243 Elf_Addr *where; 3244 3245 relrlim = (const Elf_Relr *)((const char *)obj->relr + obj->relrsize); 3246 for (relr = obj->relr; relr < relrlim; relr++) { 3247 Elf_Relr entry = *relr; 3248 3249 if ((entry & 1) == 0) { 3250 where = (Elf_Addr *)(obj->relocbase + entry); 3251 *where++ += (Elf_Addr)obj->relocbase; 3252 } else { 3253 for (long i = 0; (entry >>= 1) != 0; i++) 3254 if ((entry & 1) != 0) 3255 where[i] += (Elf_Addr)obj->relocbase; 3256 where += CHAR_BIT * sizeof(Elf_Relr) - 1; 3257 } 3258 } 3259 } 3260 3261 /* 3262 * Relocate single object. 3263 * Returns 0 on success, or -1 on failure. 3264 */ 3265 static int 3266 relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, 3267 int flags, RtldLockState *lockstate) 3268 { 3269 3270 if (obj->relocated) 3271 return (0); 3272 obj->relocated = true; 3273 if (obj != rtldobj) 3274 dbg("relocating \"%s\"", obj->path); 3275 3276 if (obj->symtab == NULL || obj->strtab == NULL || 3277 !(obj->valid_hash_sysv || obj->valid_hash_gnu)) 3278 dbg("object %s has no run-time symbol table", obj->path); 3279 3280 /* There are relocations to the write-protected text segment. */ 3281 if (obj->textrel && reloc_textrel_prot(obj, true) != 0) 3282 return (-1); 3283 3284 /* Process the non-PLT non-IFUNC relocations. */ 3285 if (reloc_non_plt(obj, rtldobj, flags, lockstate)) 3286 return (-1); 3287 reloc_relr(obj); 3288 3289 /* Re-protected the text segment. */ 3290 if (obj->textrel && reloc_textrel_prot(obj, false) != 0) 3291 return (-1); 3292 3293 /* Set the special PLT or GOT entries. */ 3294 init_pltgot(obj); 3295 3296 /* Process the PLT relocations. */ 3297 if (reloc_plt(obj, flags, lockstate) == -1) 3298 return (-1); 3299 /* Relocate the jump slots if we are doing immediate binding. */ 3300 if ((obj->bind_now || bind_now) && reloc_jmpslots(obj, flags, 3301 lockstate) == -1) 3302 return (-1); 3303 3304 if (!obj->mainprog && obj_enforce_relro(obj) == -1) 3305 return (-1); 3306 3307 /* 3308 * Set up the magic number and version in the Obj_Entry. These 3309 * were checked in the crt1.o from the original ElfKit, so we 3310 * set them for backward compatibility. 3311 */ 3312 obj->magic = RTLD_MAGIC; 3313 obj->version = RTLD_VERSION; 3314 3315 return (0); 3316 } 3317 3318 /* 3319 * Relocate newly-loaded shared objects. The argument is a pointer to 3320 * the Obj_Entry for the first such object. All objects from the first 3321 * to the end of the list of objects are relocated. Returns 0 on success, 3322 * or -1 on failure. 3323 */ 3324 static int 3325 relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj, 3326 int flags, RtldLockState *lockstate) 3327 { 3328 Obj_Entry *obj; 3329 int error; 3330 3331 for (error = 0, obj = first; obj != NULL; 3332 obj = TAILQ_NEXT(obj, next)) { 3333 if (obj->marker) 3334 continue; 3335 error = relocate_object(obj, bind_now, rtldobj, flags, 3336 lockstate); 3337 if (error == -1) 3338 break; 3339 } 3340 return (error); 3341 } 3342 3343 /* 3344 * The handling of R_MACHINE_IRELATIVE relocations and jumpslots 3345 * referencing STT_GNU_IFUNC symbols is postponed till the other 3346 * relocations are done. The indirect functions specified as 3347 * ifunc are allowed to call other symbols, so we need to have 3348 * objects relocated before asking for resolution from indirects. 3349 * 3350 * The R_MACHINE_IRELATIVE slots are resolved in greedy fashion, 3351 * instead of the usual lazy handling of PLT slots. It is 3352 * consistent with how GNU does it. 3353 */ 3354 static int 3355 resolve_object_ifunc(Obj_Entry *obj, bool bind_now, int flags, 3356 RtldLockState *lockstate) 3357 { 3358 3359 if (obj->ifuncs_resolved) 3360 return (0); 3361 obj->ifuncs_resolved = true; 3362 if (!obj->irelative && !obj->irelative_nonplt && 3363 !((obj->bind_now || bind_now) && obj->gnu_ifunc) && 3364 !obj->non_plt_gnu_ifunc) 3365 return (0); 3366 if (obj_disable_relro(obj) == -1 || 3367 (obj->irelative && reloc_iresolve(obj, lockstate) == -1) || 3368 (obj->irelative_nonplt && reloc_iresolve_nonplt(obj, 3369 lockstate) == -1) || 3370 ((obj->bind_now || bind_now) && obj->gnu_ifunc && 3371 reloc_gnu_ifunc(obj, flags, lockstate) == -1) || 3372 (obj->non_plt_gnu_ifunc && reloc_non_plt(obj, &obj_rtld, 3373 flags | SYMLOOK_IFUNC, lockstate) == -1) || 3374 obj_enforce_relro(obj) == -1) 3375 return (-1); 3376 return (0); 3377 } 3378 3379 static int 3380 initlist_objects_ifunc(Objlist *list, bool bind_now, int flags, 3381 RtldLockState *lockstate) 3382 { 3383 Objlist_Entry *elm; 3384 Obj_Entry *obj; 3385 3386 STAILQ_FOREACH(elm, list, link) { 3387 obj = elm->obj; 3388 if (obj->marker) 3389 continue; 3390 if (resolve_object_ifunc(obj, bind_now, flags, 3391 lockstate) == -1) 3392 return (-1); 3393 } 3394 return (0); 3395 } 3396 3397 /* 3398 * Cleanup procedure. It will be called (by the atexit mechanism) just 3399 * before the process exits. 3400 */ 3401 static void 3402 rtld_exit(void) 3403 { 3404 RtldLockState lockstate; 3405 3406 wlock_acquire(rtld_bind_lock, &lockstate); 3407 dbg("rtld_exit()"); 3408 objlist_call_fini(&list_fini, NULL, &lockstate); 3409 /* No need to remove the items from the list, since we are exiting. */ 3410 if (!libmap_disable) 3411 lm_fini(); 3412 lock_release(rtld_bind_lock, &lockstate); 3413 } 3414 3415 static void 3416 rtld_nop_exit(void) 3417 { 3418 } 3419 3420 /* 3421 * Iterate over a search path, translate each element, and invoke the 3422 * callback on the result. 3423 */ 3424 static void * 3425 path_enumerate(const char *path, path_enum_proc callback, 3426 const char *refobj_path, void *arg) 3427 { 3428 const char *trans; 3429 if (path == NULL) 3430 return (NULL); 3431 3432 path += strspn(path, ":;"); 3433 while (*path != '\0') { 3434 size_t len; 3435 char *res; 3436 3437 len = strcspn(path, ":;"); 3438 trans = lm_findn(refobj_path, path, len); 3439 if (trans) 3440 res = callback(trans, strlen(trans), arg); 3441 else 3442 res = callback(path, len, arg); 3443 3444 if (res != NULL) 3445 return (res); 3446 3447 path += len; 3448 path += strspn(path, ":;"); 3449 } 3450 3451 return (NULL); 3452 } 3453 3454 struct try_library_args { 3455 const char *name; 3456 size_t namelen; 3457 char *buffer; 3458 size_t buflen; 3459 int fd; 3460 }; 3461 3462 static void * 3463 try_library_path(const char *dir, size_t dirlen, void *param) 3464 { 3465 struct try_library_args *arg; 3466 int fd; 3467 3468 arg = param; 3469 if (*dir == '/' || trust) { 3470 char *pathname; 3471 3472 if (dirlen + 1 + arg->namelen + 1 > arg->buflen) 3473 return (NULL); 3474 3475 pathname = arg->buffer; 3476 strncpy(pathname, dir, dirlen); 3477 pathname[dirlen] = '/'; 3478 strcpy(pathname + dirlen + 1, arg->name); 3479 3480 dbg(" Trying \"%s\"", pathname); 3481 fd = open(pathname, O_RDONLY | O_CLOEXEC | O_VERIFY); 3482 if (fd >= 0) { 3483 dbg(" Opened \"%s\", fd %d", pathname, fd); 3484 pathname = xmalloc(dirlen + 1 + arg->namelen + 1); 3485 strcpy(pathname, arg->buffer); 3486 arg->fd = fd; 3487 return (pathname); 3488 } else { 3489 dbg(" Failed to open \"%s\": %s", 3490 pathname, rtld_strerror(errno)); 3491 } 3492 } 3493 return (NULL); 3494 } 3495 3496 static char * 3497 search_library_path(const char *name, const char *path, 3498 const char *refobj_path, int *fdp) 3499 { 3500 char *p; 3501 struct try_library_args arg; 3502 3503 if (path == NULL) 3504 return (NULL); 3505 3506 arg.name = name; 3507 arg.namelen = strlen(name); 3508 arg.buffer = xmalloc(PATH_MAX); 3509 arg.buflen = PATH_MAX; 3510 arg.fd = -1; 3511 3512 p = path_enumerate(path, try_library_path, refobj_path, &arg); 3513 *fdp = arg.fd; 3514 3515 free(arg.buffer); 3516 3517 return (p); 3518 } 3519 3520 3521 /* 3522 * Finds the library with the given name using the directory descriptors 3523 * listed in the LD_LIBRARY_PATH_FDS environment variable. 3524 * 3525 * Returns a freshly-opened close-on-exec file descriptor for the library, 3526 * or -1 if the library cannot be found. 3527 */ 3528 static char * 3529 search_library_pathfds(const char *name, const char *path, int *fdp) 3530 { 3531 char *envcopy, *fdstr, *found, *last_token; 3532 size_t len; 3533 int dirfd, fd; 3534 3535 dbg("%s('%s', '%s', fdp)", __func__, name, path); 3536 3537 /* Don't load from user-specified libdirs into setuid binaries. */ 3538 if (!trust) 3539 return (NULL); 3540 3541 /* We can't do anything if LD_LIBRARY_PATH_FDS isn't set. */ 3542 if (path == NULL) 3543 return (NULL); 3544 3545 /* LD_LIBRARY_PATH_FDS only works with relative paths. */ 3546 if (name[0] == '/') { 3547 dbg("Absolute path (%s) passed to %s", name, __func__); 3548 return (NULL); 3549 } 3550 3551 /* 3552 * Use strtok_r() to walk the FD:FD:FD list. This requires a local 3553 * copy of the path, as strtok_r rewrites separator tokens 3554 * with '\0'. 3555 */ 3556 found = NULL; 3557 envcopy = xstrdup(path); 3558 for (fdstr = strtok_r(envcopy, ":", &last_token); fdstr != NULL; 3559 fdstr = strtok_r(NULL, ":", &last_token)) { 3560 dirfd = parse_integer(fdstr); 3561 if (dirfd < 0) { 3562 _rtld_error("failed to parse directory FD: '%s'", 3563 fdstr); 3564 break; 3565 } 3566 fd = __sys_openat(dirfd, name, O_RDONLY | O_CLOEXEC | O_VERIFY); 3567 if (fd >= 0) { 3568 *fdp = fd; 3569 len = strlen(fdstr) + strlen(name) + 3; 3570 found = xmalloc(len); 3571 if (rtld_snprintf(found, len, "#%d/%s", dirfd, name) < 0) { 3572 _rtld_error("error generating '%d/%s'", 3573 dirfd, name); 3574 rtld_die(); 3575 } 3576 dbg("open('%s') => %d", found, fd); 3577 break; 3578 } 3579 } 3580 free(envcopy); 3581 3582 return (found); 3583 } 3584 3585 3586 int 3587 dlclose(void *handle) 3588 { 3589 RtldLockState lockstate; 3590 int error; 3591 3592 wlock_acquire(rtld_bind_lock, &lockstate); 3593 error = dlclose_locked(handle, &lockstate); 3594 lock_release(rtld_bind_lock, &lockstate); 3595 return (error); 3596 } 3597 3598 static int 3599 dlclose_locked(void *handle, RtldLockState *lockstate) 3600 { 3601 Obj_Entry *root; 3602 3603 root = dlcheck(handle); 3604 if (root == NULL) 3605 return (-1); 3606 LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount, 3607 root->path); 3608 3609 /* Unreference the object and its dependencies. */ 3610 root->dl_refcount--; 3611 3612 if (root->refcount == 1) { 3613 /* 3614 * The object will be no longer referenced, so we must unload it. 3615 * First, call the fini functions. 3616 */ 3617 objlist_call_fini(&list_fini, root, lockstate); 3618 3619 unref_dag(root); 3620 3621 /* Finish cleaning up the newly-unreferenced objects. */ 3622 GDB_STATE(RT_DELETE,&root->linkmap); 3623 unload_object(root, lockstate); 3624 GDB_STATE(RT_CONSISTENT,NULL); 3625 } else 3626 unref_dag(root); 3627 3628 LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL); 3629 return (0); 3630 } 3631 3632 char * 3633 dlerror(void) 3634 { 3635 if (*(lockinfo.dlerror_seen()) != 0) 3636 return (NULL); 3637 *lockinfo.dlerror_seen() = 1; 3638 return (lockinfo.dlerror_loc()); 3639 } 3640 3641 /* 3642 * This function is deprecated and has no effect. 3643 */ 3644 void 3645 dllockinit(void *context, 3646 void *(*_lock_create)(void *context) __unused, 3647 void (*_rlock_acquire)(void *lock) __unused, 3648 void (*_wlock_acquire)(void *lock) __unused, 3649 void (*_lock_release)(void *lock) __unused, 3650 void (*_lock_destroy)(void *lock) __unused, 3651 void (*context_destroy)(void *context)) 3652 { 3653 static void *cur_context; 3654 static void (*cur_context_destroy)(void *); 3655 3656 /* Just destroy the context from the previous call, if necessary. */ 3657 if (cur_context_destroy != NULL) 3658 cur_context_destroy(cur_context); 3659 cur_context = context; 3660 cur_context_destroy = context_destroy; 3661 } 3662 3663 void * 3664 dlopen(const char *name, int mode) 3665 { 3666 3667 return (rtld_dlopen(name, -1, mode)); 3668 } 3669 3670 void * 3671 fdlopen(int fd, int mode) 3672 { 3673 3674 return (rtld_dlopen(NULL, fd, mode)); 3675 } 3676 3677 static void * 3678 rtld_dlopen(const char *name, int fd, int mode) 3679 { 3680 RtldLockState lockstate; 3681 int lo_flags; 3682 3683 LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name); 3684 ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1"; 3685 if (ld_tracing != NULL) { 3686 rlock_acquire(rtld_bind_lock, &lockstate); 3687 if (sigsetjmp(lockstate.env, 0) != 0) 3688 lock_upgrade(rtld_bind_lock, &lockstate); 3689 environ = __DECONST(char **, *get_program_var_addr("environ", &lockstate)); 3690 lock_release(rtld_bind_lock, &lockstate); 3691 } 3692 lo_flags = RTLD_LO_DLOPEN; 3693 if (mode & RTLD_NODELETE) 3694 lo_flags |= RTLD_LO_NODELETE; 3695 if (mode & RTLD_NOLOAD) 3696 lo_flags |= RTLD_LO_NOLOAD; 3697 if (mode & RTLD_DEEPBIND) 3698 lo_flags |= RTLD_LO_DEEPBIND; 3699 if (ld_tracing != NULL) 3700 lo_flags |= RTLD_LO_TRACE | RTLD_LO_IGNSTLS; 3701 3702 return (dlopen_object(name, fd, obj_main, lo_flags, 3703 mode & (RTLD_MODEMASK | RTLD_GLOBAL), NULL)); 3704 } 3705 3706 static void 3707 dlopen_cleanup(Obj_Entry *obj, RtldLockState *lockstate) 3708 { 3709 3710 obj->dl_refcount--; 3711 unref_dag(obj); 3712 if (obj->refcount == 0) 3713 unload_object(obj, lockstate); 3714 } 3715 3716 static Obj_Entry * 3717 dlopen_object(const char *name, int fd, Obj_Entry *refobj, int lo_flags, 3718 int mode, RtldLockState *lockstate) 3719 { 3720 Obj_Entry *old_obj_tail; 3721 Obj_Entry *obj; 3722 Objlist initlist; 3723 RtldLockState mlockstate; 3724 int result; 3725 3726 dbg("dlopen_object name \"%s\" fd %d refobj \"%s\" lo_flags %#x mode %#x", 3727 name != NULL ? name : "<null>", fd, refobj == NULL ? "<null>" : 3728 refobj->path, lo_flags, mode); 3729 objlist_init(&initlist); 3730 3731 if (lockstate == NULL && !(lo_flags & RTLD_LO_EARLY)) { 3732 wlock_acquire(rtld_bind_lock, &mlockstate); 3733 lockstate = &mlockstate; 3734 } 3735 GDB_STATE(RT_ADD,NULL); 3736 3737 old_obj_tail = globallist_curr(TAILQ_LAST(&obj_list, obj_entry_q)); 3738 obj = NULL; 3739 if (name == NULL && fd == -1) { 3740 obj = obj_main; 3741 obj->refcount++; 3742 } else { 3743 obj = load_object(name, fd, refobj, lo_flags); 3744 } 3745 3746 if (obj) { 3747 obj->dl_refcount++; 3748 if (mode & RTLD_GLOBAL && objlist_find(&list_global, obj) == NULL) 3749 objlist_push_tail(&list_global, obj); 3750 if (globallist_next(old_obj_tail) != NULL) { 3751 /* We loaded something new. */ 3752 assert(globallist_next(old_obj_tail) == obj); 3753 if ((lo_flags & RTLD_LO_DEEPBIND) != 0) 3754 obj->symbolic = true; 3755 result = 0; 3756 if ((lo_flags & (RTLD_LO_EARLY | RTLD_LO_IGNSTLS)) == 0 && 3757 obj->static_tls && !allocate_tls_offset(obj)) { 3758 _rtld_error("%s: No space available " 3759 "for static Thread Local Storage", obj->path); 3760 result = -1; 3761 } 3762 if (result != -1) 3763 result = load_needed_objects(obj, lo_flags & (RTLD_LO_DLOPEN | 3764 RTLD_LO_EARLY | RTLD_LO_IGNSTLS | RTLD_LO_TRACE)); 3765 init_dag(obj); 3766 ref_dag(obj); 3767 if (result != -1) 3768 result = rtld_verify_versions(&obj->dagmembers); 3769 if (result != -1 && ld_tracing) 3770 goto trace; 3771 if (result == -1 || relocate_object_dag(obj, 3772 (mode & RTLD_MODEMASK) == RTLD_NOW, &obj_rtld, 3773 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 3774 lockstate) == -1) { 3775 dlopen_cleanup(obj, lockstate); 3776 obj = NULL; 3777 } else if (lo_flags & RTLD_LO_EARLY) { 3778 /* 3779 * Do not call the init functions for early loaded 3780 * filtees. The image is still not initialized enough 3781 * for them to work. 3782 * 3783 * Our object is found by the global object list and 3784 * will be ordered among all init calls done right 3785 * before transferring control to main. 3786 */ 3787 } else { 3788 /* Make list of init functions to call. */ 3789 initlist_add_objects(obj, obj, &initlist); 3790 } 3791 /* 3792 * Process all no_delete or global objects here, given 3793 * them own DAGs to prevent their dependencies from being 3794 * unloaded. This has to be done after we have loaded all 3795 * of the dependencies, so that we do not miss any. 3796 */ 3797 if (obj != NULL) 3798 process_z(obj); 3799 } else { 3800 /* 3801 * Bump the reference counts for objects on this DAG. If 3802 * this is the first dlopen() call for the object that was 3803 * already loaded as a dependency, initialize the dag 3804 * starting at it. 3805 */ 3806 init_dag(obj); 3807 ref_dag(obj); 3808 3809 if ((lo_flags & RTLD_LO_TRACE) != 0) 3810 goto trace; 3811 } 3812 if (obj != NULL && ((lo_flags & RTLD_LO_NODELETE) != 0 || 3813 obj->z_nodelete) && !obj->ref_nodel) { 3814 dbg("obj %s nodelete", obj->path); 3815 ref_dag(obj); 3816 obj->z_nodelete = obj->ref_nodel = true; 3817 } 3818 } 3819 3820 LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0, 3821 name); 3822 GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL); 3823 3824 if ((lo_flags & RTLD_LO_EARLY) == 0) { 3825 map_stacks_exec(lockstate); 3826 if (obj != NULL) 3827 distribute_static_tls(&initlist, lockstate); 3828 } 3829 3830 if (initlist_objects_ifunc(&initlist, (mode & RTLD_MODEMASK) == RTLD_NOW, 3831 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 3832 lockstate) == -1) { 3833 objlist_clear(&initlist); 3834 dlopen_cleanup(obj, lockstate); 3835 if (lockstate == &mlockstate) 3836 lock_release(rtld_bind_lock, lockstate); 3837 return (NULL); 3838 } 3839 3840 if (!(lo_flags & RTLD_LO_EARLY)) { 3841 /* Call the init functions. */ 3842 objlist_call_init(&initlist, lockstate); 3843 } 3844 objlist_clear(&initlist); 3845 if (lockstate == &mlockstate) 3846 lock_release(rtld_bind_lock, lockstate); 3847 return (obj); 3848 trace: 3849 trace_loaded_objects(obj, false); 3850 if (lockstate == &mlockstate) 3851 lock_release(rtld_bind_lock, lockstate); 3852 exit(0); 3853 } 3854 3855 static void * 3856 do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve, 3857 int flags) 3858 { 3859 DoneList donelist; 3860 const Obj_Entry *obj, *defobj; 3861 const Elf_Sym *def; 3862 SymLook req; 3863 RtldLockState lockstate; 3864 tls_index ti; 3865 void *sym; 3866 int res; 3867 3868 def = NULL; 3869 defobj = NULL; 3870 symlook_init(&req, name); 3871 req.ventry = ve; 3872 req.flags = flags | SYMLOOK_IN_PLT; 3873 req.lockstate = &lockstate; 3874 3875 LD_UTRACE(UTRACE_DLSYM_START, handle, NULL, 0, 0, name); 3876 rlock_acquire(rtld_bind_lock, &lockstate); 3877 if (sigsetjmp(lockstate.env, 0) != 0) 3878 lock_upgrade(rtld_bind_lock, &lockstate); 3879 if (handle == NULL || handle == RTLD_NEXT || 3880 handle == RTLD_DEFAULT || handle == RTLD_SELF) { 3881 3882 if ((obj = obj_from_addr(retaddr)) == NULL) { 3883 _rtld_error("Cannot determine caller's shared object"); 3884 lock_release(rtld_bind_lock, &lockstate); 3885 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 3886 return (NULL); 3887 } 3888 if (handle == NULL) { /* Just the caller's shared object. */ 3889 res = symlook_obj(&req, obj); 3890 if (res == 0) { 3891 def = req.sym_out; 3892 defobj = req.defobj_out; 3893 } 3894 } else if (handle == RTLD_NEXT || /* Objects after caller's */ 3895 handle == RTLD_SELF) { /* ... caller included */ 3896 if (handle == RTLD_NEXT) 3897 obj = globallist_next(obj); 3898 for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 3899 if (obj->marker) 3900 continue; 3901 res = symlook_obj(&req, obj); 3902 if (res == 0) { 3903 if (def == NULL || (ld_dynamic_weak && 3904 ELF_ST_BIND(req.sym_out->st_info) != STB_WEAK)) { 3905 def = req.sym_out; 3906 defobj = req.defobj_out; 3907 if (!ld_dynamic_weak || 3908 ELF_ST_BIND(def->st_info) != STB_WEAK) 3909 break; 3910 } 3911 } 3912 } 3913 /* 3914 * Search the dynamic linker itself, and possibly resolve the 3915 * symbol from there. This is how the application links to 3916 * dynamic linker services such as dlopen. 3917 * Note that we ignore ld_dynamic_weak == false case, 3918 * always overriding weak symbols by rtld definitions. 3919 */ 3920 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 3921 res = symlook_obj(&req, &obj_rtld); 3922 if (res == 0) { 3923 def = req.sym_out; 3924 defobj = req.defobj_out; 3925 } 3926 } 3927 } else { 3928 assert(handle == RTLD_DEFAULT); 3929 res = symlook_default(&req, obj); 3930 if (res == 0) { 3931 defobj = req.defobj_out; 3932 def = req.sym_out; 3933 } 3934 } 3935 } else { 3936 if ((obj = dlcheck(handle)) == NULL) { 3937 lock_release(rtld_bind_lock, &lockstate); 3938 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 3939 return (NULL); 3940 } 3941 3942 donelist_init(&donelist); 3943 if (obj->mainprog) { 3944 /* Handle obtained by dlopen(NULL, ...) implies global scope. */ 3945 res = symlook_global(&req, &donelist); 3946 if (res == 0) { 3947 def = req.sym_out; 3948 defobj = req.defobj_out; 3949 } 3950 /* 3951 * Search the dynamic linker itself, and possibly resolve the 3952 * symbol from there. This is how the application links to 3953 * dynamic linker services such as dlopen. 3954 */ 3955 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 3956 res = symlook_obj(&req, &obj_rtld); 3957 if (res == 0) { 3958 def = req.sym_out; 3959 defobj = req.defobj_out; 3960 } 3961 } 3962 } 3963 else { 3964 /* Search the whole DAG rooted at the given object. */ 3965 res = symlook_list(&req, &obj->dagmembers, &donelist); 3966 if (res == 0) { 3967 def = req.sym_out; 3968 defobj = req.defobj_out; 3969 } 3970 } 3971 } 3972 3973 if (def != NULL) { 3974 lock_release(rtld_bind_lock, &lockstate); 3975 3976 /* 3977 * The value required by the caller is derived from the value 3978 * of the symbol. this is simply the relocated value of the 3979 * symbol. 3980 */ 3981 if (ELF_ST_TYPE(def->st_info) == STT_FUNC) 3982 sym = make_function_pointer(def, defobj); 3983 else if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 3984 sym = rtld_resolve_ifunc(defobj, def); 3985 else if (ELF_ST_TYPE(def->st_info) == STT_TLS) { 3986 ti.ti_module = defobj->tlsindex; 3987 ti.ti_offset = def->st_value; 3988 sym = __tls_get_addr(&ti); 3989 } else 3990 sym = defobj->relocbase + def->st_value; 3991 LD_UTRACE(UTRACE_DLSYM_STOP, handle, sym, 0, 0, name); 3992 return (sym); 3993 } 3994 3995 _rtld_error("Undefined symbol \"%s%s%s\"", name, ve != NULL ? "@" : "", 3996 ve != NULL ? ve->name : ""); 3997 lock_release(rtld_bind_lock, &lockstate); 3998 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 3999 return (NULL); 4000 } 4001 4002 void * 4003 dlsym(void *handle, const char *name) 4004 { 4005 return (do_dlsym(handle, name, __builtin_return_address(0), NULL, 4006 SYMLOOK_DLSYM)); 4007 } 4008 4009 dlfunc_t 4010 dlfunc(void *handle, const char *name) 4011 { 4012 union { 4013 void *d; 4014 dlfunc_t f; 4015 } rv; 4016 4017 rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL, 4018 SYMLOOK_DLSYM); 4019 return (rv.f); 4020 } 4021 4022 void * 4023 dlvsym(void *handle, const char *name, const char *version) 4024 { 4025 Ver_Entry ventry; 4026 4027 ventry.name = version; 4028 ventry.file = NULL; 4029 ventry.hash = elf_hash(version); 4030 ventry.flags= 0; 4031 return (do_dlsym(handle, name, __builtin_return_address(0), &ventry, 4032 SYMLOOK_DLSYM)); 4033 } 4034 4035 int 4036 _rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info) 4037 { 4038 const Obj_Entry *obj; 4039 RtldLockState lockstate; 4040 4041 rlock_acquire(rtld_bind_lock, &lockstate); 4042 obj = obj_from_addr(addr); 4043 if (obj == NULL) { 4044 _rtld_error("No shared object contains address"); 4045 lock_release(rtld_bind_lock, &lockstate); 4046 return (0); 4047 } 4048 rtld_fill_dl_phdr_info(obj, phdr_info); 4049 lock_release(rtld_bind_lock, &lockstate); 4050 return (1); 4051 } 4052 4053 int 4054 dladdr(const void *addr, Dl_info *info) 4055 { 4056 const Obj_Entry *obj; 4057 const Elf_Sym *def; 4058 void *symbol_addr; 4059 unsigned long symoffset; 4060 RtldLockState lockstate; 4061 4062 rlock_acquire(rtld_bind_lock, &lockstate); 4063 obj = obj_from_addr(addr); 4064 if (obj == NULL) { 4065 _rtld_error("No shared object contains address"); 4066 lock_release(rtld_bind_lock, &lockstate); 4067 return (0); 4068 } 4069 info->dli_fname = obj->path; 4070 info->dli_fbase = obj->mapbase; 4071 info->dli_saddr = (void *)0; 4072 info->dli_sname = NULL; 4073 4074 /* 4075 * Walk the symbol list looking for the symbol whose address is 4076 * closest to the address sent in. 4077 */ 4078 for (symoffset = 0; symoffset < obj->dynsymcount; symoffset++) { 4079 def = obj->symtab + symoffset; 4080 4081 /* 4082 * For skip the symbol if st_shndx is either SHN_UNDEF or 4083 * SHN_COMMON. 4084 */ 4085 if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON) 4086 continue; 4087 4088 /* 4089 * If the symbol is greater than the specified address, or if it 4090 * is further away from addr than the current nearest symbol, 4091 * then reject it. 4092 */ 4093 symbol_addr = obj->relocbase + def->st_value; 4094 if (symbol_addr > addr || symbol_addr < info->dli_saddr) 4095 continue; 4096 4097 /* Update our idea of the nearest symbol. */ 4098 info->dli_sname = obj->strtab + def->st_name; 4099 info->dli_saddr = symbol_addr; 4100 4101 /* Exact match? */ 4102 if (info->dli_saddr == addr) 4103 break; 4104 } 4105 lock_release(rtld_bind_lock, &lockstate); 4106 return (1); 4107 } 4108 4109 int 4110 dlinfo(void *handle, int request, void *p) 4111 { 4112 const Obj_Entry *obj; 4113 RtldLockState lockstate; 4114 int error; 4115 4116 rlock_acquire(rtld_bind_lock, &lockstate); 4117 4118 if (handle == NULL || handle == RTLD_SELF) { 4119 void *retaddr; 4120 4121 retaddr = __builtin_return_address(0); /* __GNUC__ only */ 4122 if ((obj = obj_from_addr(retaddr)) == NULL) 4123 _rtld_error("Cannot determine caller's shared object"); 4124 } else 4125 obj = dlcheck(handle); 4126 4127 if (obj == NULL) { 4128 lock_release(rtld_bind_lock, &lockstate); 4129 return (-1); 4130 } 4131 4132 error = 0; 4133 switch (request) { 4134 case RTLD_DI_LINKMAP: 4135 *((struct link_map const **)p) = &obj->linkmap; 4136 break; 4137 case RTLD_DI_ORIGIN: 4138 error = rtld_dirname(obj->path, p); 4139 break; 4140 4141 case RTLD_DI_SERINFOSIZE: 4142 case RTLD_DI_SERINFO: 4143 error = do_search_info(obj, request, (struct dl_serinfo *)p); 4144 break; 4145 4146 default: 4147 _rtld_error("Invalid request %d passed to dlinfo()", request); 4148 error = -1; 4149 } 4150 4151 lock_release(rtld_bind_lock, &lockstate); 4152 4153 return (error); 4154 } 4155 4156 static void 4157 rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info) 4158 { 4159 uintptr_t **dtvp; 4160 4161 phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase; 4162 phdr_info->dlpi_name = obj->path; 4163 phdr_info->dlpi_phdr = obj->phdr; 4164 phdr_info->dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]); 4165 phdr_info->dlpi_tls_modid = obj->tlsindex; 4166 dtvp = &_tcb_get()->tcb_dtv; 4167 phdr_info->dlpi_tls_data = (char *)tls_get_addr_slow(dtvp, 4168 obj->tlsindex, 0, true) + TLS_DTV_OFFSET; 4169 phdr_info->dlpi_adds = obj_loads; 4170 phdr_info->dlpi_subs = obj_loads - obj_count; 4171 } 4172 4173 int 4174 dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param) 4175 { 4176 struct dl_phdr_info phdr_info; 4177 Obj_Entry *obj, marker; 4178 RtldLockState bind_lockstate, phdr_lockstate; 4179 int error; 4180 4181 init_marker(&marker); 4182 error = 0; 4183 4184 wlock_acquire(rtld_phdr_lock, &phdr_lockstate); 4185 wlock_acquire(rtld_bind_lock, &bind_lockstate); 4186 for (obj = globallist_curr(TAILQ_FIRST(&obj_list)); obj != NULL;) { 4187 TAILQ_INSERT_AFTER(&obj_list, obj, &marker, next); 4188 rtld_fill_dl_phdr_info(obj, &phdr_info); 4189 hold_object(obj); 4190 lock_release(rtld_bind_lock, &bind_lockstate); 4191 4192 error = callback(&phdr_info, sizeof phdr_info, param); 4193 4194 wlock_acquire(rtld_bind_lock, &bind_lockstate); 4195 unhold_object(obj); 4196 obj = globallist_next(&marker); 4197 TAILQ_REMOVE(&obj_list, &marker, next); 4198 if (error != 0) { 4199 lock_release(rtld_bind_lock, &bind_lockstate); 4200 lock_release(rtld_phdr_lock, &phdr_lockstate); 4201 return (error); 4202 } 4203 } 4204 4205 if (error == 0) { 4206 rtld_fill_dl_phdr_info(&obj_rtld, &phdr_info); 4207 lock_release(rtld_bind_lock, &bind_lockstate); 4208 error = callback(&phdr_info, sizeof(phdr_info), param); 4209 } 4210 lock_release(rtld_phdr_lock, &phdr_lockstate); 4211 return (error); 4212 } 4213 4214 static void * 4215 fill_search_info(const char *dir, size_t dirlen, void *param) 4216 { 4217 struct fill_search_info_args *arg; 4218 4219 arg = param; 4220 4221 if (arg->request == RTLD_DI_SERINFOSIZE) { 4222 arg->serinfo->dls_cnt ++; 4223 arg->serinfo->dls_size += sizeof(struct dl_serpath) + dirlen + 1; 4224 } else { 4225 struct dl_serpath *s_entry; 4226 4227 s_entry = arg->serpath; 4228 s_entry->dls_name = arg->strspace; 4229 s_entry->dls_flags = arg->flags; 4230 4231 strncpy(arg->strspace, dir, dirlen); 4232 arg->strspace[dirlen] = '\0'; 4233 4234 arg->strspace += dirlen + 1; 4235 arg->serpath++; 4236 } 4237 4238 return (NULL); 4239 } 4240 4241 static int 4242 do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info) 4243 { 4244 struct dl_serinfo _info; 4245 struct fill_search_info_args args; 4246 4247 args.request = RTLD_DI_SERINFOSIZE; 4248 args.serinfo = &_info; 4249 4250 _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 4251 _info.dls_cnt = 0; 4252 4253 path_enumerate(obj->rpath, fill_search_info, NULL, &args); 4254 path_enumerate(ld_library_path, fill_search_info, NULL, &args); 4255 path_enumerate(obj->runpath, fill_search_info, NULL, &args); 4256 path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, &args); 4257 if (!obj->z_nodeflib) 4258 path_enumerate(ld_standard_library_path, fill_search_info, NULL, &args); 4259 4260 4261 if (request == RTLD_DI_SERINFOSIZE) { 4262 info->dls_size = _info.dls_size; 4263 info->dls_cnt = _info.dls_cnt; 4264 return (0); 4265 } 4266 4267 if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) { 4268 _rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()"); 4269 return (-1); 4270 } 4271 4272 args.request = RTLD_DI_SERINFO; 4273 args.serinfo = info; 4274 args.serpath = &info->dls_serpath[0]; 4275 args.strspace = (char *)&info->dls_serpath[_info.dls_cnt]; 4276 4277 args.flags = LA_SER_RUNPATH; 4278 if (path_enumerate(obj->rpath, fill_search_info, NULL, &args) != NULL) 4279 return (-1); 4280 4281 args.flags = LA_SER_LIBPATH; 4282 if (path_enumerate(ld_library_path, fill_search_info, NULL, &args) != NULL) 4283 return (-1); 4284 4285 args.flags = LA_SER_RUNPATH; 4286 if (path_enumerate(obj->runpath, fill_search_info, NULL, &args) != NULL) 4287 return (-1); 4288 4289 args.flags = LA_SER_CONFIG; 4290 if (path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, &args) 4291 != NULL) 4292 return (-1); 4293 4294 args.flags = LA_SER_DEFAULT; 4295 if (!obj->z_nodeflib && path_enumerate(ld_standard_library_path, 4296 fill_search_info, NULL, &args) != NULL) 4297 return (-1); 4298 return (0); 4299 } 4300 4301 static int 4302 rtld_dirname(const char *path, char *bname) 4303 { 4304 const char *endp; 4305 4306 /* Empty or NULL string gets treated as "." */ 4307 if (path == NULL || *path == '\0') { 4308 bname[0] = '.'; 4309 bname[1] = '\0'; 4310 return (0); 4311 } 4312 4313 /* Strip trailing slashes */ 4314 endp = path + strlen(path) - 1; 4315 while (endp > path && *endp == '/') 4316 endp--; 4317 4318 /* Find the start of the dir */ 4319 while (endp > path && *endp != '/') 4320 endp--; 4321 4322 /* Either the dir is "/" or there are no slashes */ 4323 if (endp == path) { 4324 bname[0] = *endp == '/' ? '/' : '.'; 4325 bname[1] = '\0'; 4326 return (0); 4327 } else { 4328 do { 4329 endp--; 4330 } while (endp > path && *endp == '/'); 4331 } 4332 4333 if (endp - path + 2 > PATH_MAX) 4334 { 4335 _rtld_error("Filename is too long: %s", path); 4336 return(-1); 4337 } 4338 4339 strncpy(bname, path, endp - path + 1); 4340 bname[endp - path + 1] = '\0'; 4341 return (0); 4342 } 4343 4344 static int 4345 rtld_dirname_abs(const char *path, char *base) 4346 { 4347 char *last; 4348 4349 if (realpath(path, base) == NULL) { 4350 _rtld_error("realpath \"%s\" failed (%s)", path, 4351 rtld_strerror(errno)); 4352 return (-1); 4353 } 4354 dbg("%s -> %s", path, base); 4355 last = strrchr(base, '/'); 4356 if (last == NULL) { 4357 _rtld_error("non-abs result from realpath \"%s\"", path); 4358 return (-1); 4359 } 4360 if (last != base) 4361 *last = '\0'; 4362 return (0); 4363 } 4364 4365 static void 4366 linkmap_add(Obj_Entry *obj) 4367 { 4368 struct link_map *l, *prev; 4369 4370 l = &obj->linkmap; 4371 l->l_name = obj->path; 4372 l->l_base = obj->mapbase; 4373 l->l_ld = obj->dynamic; 4374 l->l_addr = obj->relocbase; 4375 4376 if (r_debug.r_map == NULL) { 4377 r_debug.r_map = l; 4378 return; 4379 } 4380 4381 /* 4382 * Scan to the end of the list, but not past the entry for the 4383 * dynamic linker, which we want to keep at the very end. 4384 */ 4385 for (prev = r_debug.r_map; 4386 prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap; 4387 prev = prev->l_next) 4388 ; 4389 4390 /* Link in the new entry. */ 4391 l->l_prev = prev; 4392 l->l_next = prev->l_next; 4393 if (l->l_next != NULL) 4394 l->l_next->l_prev = l; 4395 prev->l_next = l; 4396 } 4397 4398 static void 4399 linkmap_delete(Obj_Entry *obj) 4400 { 4401 struct link_map *l; 4402 4403 l = &obj->linkmap; 4404 if (l->l_prev == NULL) { 4405 if ((r_debug.r_map = l->l_next) != NULL) 4406 l->l_next->l_prev = NULL; 4407 return; 4408 } 4409 4410 if ((l->l_prev->l_next = l->l_next) != NULL) 4411 l->l_next->l_prev = l->l_prev; 4412 } 4413 4414 /* 4415 * Function for the debugger to set a breakpoint on to gain control. 4416 * 4417 * The two parameters allow the debugger to easily find and determine 4418 * what the runtime loader is doing and to whom it is doing it. 4419 * 4420 * When the loadhook trap is hit (r_debug_state, set at program 4421 * initialization), the arguments can be found on the stack: 4422 * 4423 * +8 struct link_map *m 4424 * +4 struct r_debug *rd 4425 * +0 RetAddr 4426 */ 4427 void 4428 r_debug_state(struct r_debug* rd __unused, struct link_map *m __unused) 4429 { 4430 /* 4431 * The following is a hack to force the compiler to emit calls to 4432 * this function, even when optimizing. If the function is empty, 4433 * the compiler is not obliged to emit any code for calls to it, 4434 * even when marked __noinline. However, gdb depends on those 4435 * calls being made. 4436 */ 4437 __compiler_membar(); 4438 } 4439 4440 /* 4441 * A function called after init routines have completed. This can be used to 4442 * break before a program's entry routine is called, and can be used when 4443 * main is not available in the symbol table. 4444 */ 4445 void 4446 _r_debug_postinit(struct link_map *m __unused) 4447 { 4448 4449 /* See r_debug_state(). */ 4450 __compiler_membar(); 4451 } 4452 4453 static void 4454 release_object(Obj_Entry *obj) 4455 { 4456 4457 if (obj->holdcount > 0) { 4458 obj->unholdfree = true; 4459 return; 4460 } 4461 munmap(obj->mapbase, obj->mapsize); 4462 linkmap_delete(obj); 4463 obj_free(obj); 4464 } 4465 4466 /* 4467 * Get address of the pointer variable in the main program. 4468 * Prefer non-weak symbol over the weak one. 4469 */ 4470 static const void ** 4471 get_program_var_addr(const char *name, RtldLockState *lockstate) 4472 { 4473 SymLook req; 4474 DoneList donelist; 4475 4476 symlook_init(&req, name); 4477 req.lockstate = lockstate; 4478 donelist_init(&donelist); 4479 if (symlook_global(&req, &donelist) != 0) 4480 return (NULL); 4481 if (ELF_ST_TYPE(req.sym_out->st_info) == STT_FUNC) 4482 return ((const void **)make_function_pointer(req.sym_out, 4483 req.defobj_out)); 4484 else if (ELF_ST_TYPE(req.sym_out->st_info) == STT_GNU_IFUNC) 4485 return ((const void **)rtld_resolve_ifunc(req.defobj_out, req.sym_out)); 4486 else 4487 return ((const void **)(req.defobj_out->relocbase + 4488 req.sym_out->st_value)); 4489 } 4490 4491 /* 4492 * Set a pointer variable in the main program to the given value. This 4493 * is used to set key variables such as "environ" before any of the 4494 * init functions are called. 4495 */ 4496 static void 4497 set_program_var(const char *name, const void *value) 4498 { 4499 const void **addr; 4500 4501 if ((addr = get_program_var_addr(name, NULL)) != NULL) { 4502 dbg("\"%s\": *%p <-- %p", name, addr, value); 4503 *addr = value; 4504 } 4505 } 4506 4507 /* 4508 * Search the global objects, including dependencies and main object, 4509 * for the given symbol. 4510 */ 4511 static int 4512 symlook_global(SymLook *req, DoneList *donelist) 4513 { 4514 SymLook req1; 4515 const Objlist_Entry *elm; 4516 int res; 4517 4518 symlook_init_from_req(&req1, req); 4519 4520 /* Search all objects loaded at program start up. */ 4521 if (req->defobj_out == NULL || (ld_dynamic_weak && 4522 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK)) { 4523 res = symlook_list(&req1, &list_main, donelist); 4524 if (res == 0 && (!ld_dynamic_weak || req->defobj_out == NULL || 4525 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4526 req->sym_out = req1.sym_out; 4527 req->defobj_out = req1.defobj_out; 4528 assert(req->defobj_out != NULL); 4529 } 4530 } 4531 4532 /* Search all DAGs whose roots are RTLD_GLOBAL objects. */ 4533 STAILQ_FOREACH(elm, &list_global, link) { 4534 if (req->defobj_out != NULL && (!ld_dynamic_weak || 4535 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK)) 4536 break; 4537 res = symlook_list(&req1, &elm->obj->dagmembers, donelist); 4538 if (res == 0 && (req->defobj_out == NULL || 4539 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4540 req->sym_out = req1.sym_out; 4541 req->defobj_out = req1.defobj_out; 4542 assert(req->defobj_out != NULL); 4543 } 4544 } 4545 4546 return (req->sym_out != NULL ? 0 : ESRCH); 4547 } 4548 4549 /* 4550 * Given a symbol name in a referencing object, find the corresponding 4551 * definition of the symbol. Returns a pointer to the symbol, or NULL if 4552 * no definition was found. Returns a pointer to the Obj_Entry of the 4553 * defining object via the reference parameter DEFOBJ_OUT. 4554 */ 4555 static int 4556 symlook_default(SymLook *req, const Obj_Entry *refobj) 4557 { 4558 DoneList donelist; 4559 const Objlist_Entry *elm; 4560 SymLook req1; 4561 int res; 4562 4563 donelist_init(&donelist); 4564 symlook_init_from_req(&req1, req); 4565 4566 /* 4567 * Look first in the referencing object if linked symbolically, 4568 * and similarly handle protected symbols. 4569 */ 4570 res = symlook_obj(&req1, refobj); 4571 if (res == 0 && (refobj->symbolic || 4572 ELF_ST_VISIBILITY(req1.sym_out->st_other) == STV_PROTECTED)) { 4573 req->sym_out = req1.sym_out; 4574 req->defobj_out = req1.defobj_out; 4575 assert(req->defobj_out != NULL); 4576 } 4577 if (refobj->symbolic || req->defobj_out != NULL) 4578 donelist_check(&donelist, refobj); 4579 4580 symlook_global(req, &donelist); 4581 4582 /* Search all dlopened DAGs containing the referencing object. */ 4583 STAILQ_FOREACH(elm, &refobj->dldags, link) { 4584 if (req->sym_out != NULL && (!ld_dynamic_weak || 4585 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK)) 4586 break; 4587 res = symlook_list(&req1, &elm->obj->dagmembers, &donelist); 4588 if (res == 0 && (req->sym_out == NULL || 4589 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4590 req->sym_out = req1.sym_out; 4591 req->defobj_out = req1.defobj_out; 4592 assert(req->defobj_out != NULL); 4593 } 4594 } 4595 4596 /* 4597 * Search the dynamic linker itself, and possibly resolve the 4598 * symbol from there. This is how the application links to 4599 * dynamic linker services such as dlopen. 4600 */ 4601 if (req->sym_out == NULL || 4602 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 4603 res = symlook_obj(&req1, &obj_rtld); 4604 if (res == 0) { 4605 req->sym_out = req1.sym_out; 4606 req->defobj_out = req1.defobj_out; 4607 assert(req->defobj_out != NULL); 4608 } 4609 } 4610 4611 return (req->sym_out != NULL ? 0 : ESRCH); 4612 } 4613 4614 static int 4615 symlook_list(SymLook *req, const Objlist *objlist, DoneList *dlp) 4616 { 4617 const Elf_Sym *def; 4618 const Obj_Entry *defobj; 4619 const Objlist_Entry *elm; 4620 SymLook req1; 4621 int res; 4622 4623 def = NULL; 4624 defobj = NULL; 4625 STAILQ_FOREACH(elm, objlist, link) { 4626 if (donelist_check(dlp, elm->obj)) 4627 continue; 4628 symlook_init_from_req(&req1, req); 4629 if ((res = symlook_obj(&req1, elm->obj)) == 0) { 4630 if (def == NULL || (ld_dynamic_weak && 4631 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4632 def = req1.sym_out; 4633 defobj = req1.defobj_out; 4634 if (!ld_dynamic_weak || ELF_ST_BIND(def->st_info) != STB_WEAK) 4635 break; 4636 } 4637 } 4638 } 4639 if (def != NULL) { 4640 req->sym_out = def; 4641 req->defobj_out = defobj; 4642 return (0); 4643 } 4644 return (ESRCH); 4645 } 4646 4647 /* 4648 * Search the chain of DAGS cointed to by the given Needed_Entry 4649 * for a symbol of the given name. Each DAG is scanned completely 4650 * before advancing to the next one. Returns a pointer to the symbol, 4651 * or NULL if no definition was found. 4652 */ 4653 static int 4654 symlook_needed(SymLook *req, const Needed_Entry *needed, DoneList *dlp) 4655 { 4656 const Elf_Sym *def; 4657 const Needed_Entry *n; 4658 const Obj_Entry *defobj; 4659 SymLook req1; 4660 int res; 4661 4662 def = NULL; 4663 defobj = NULL; 4664 symlook_init_from_req(&req1, req); 4665 for (n = needed; n != NULL; n = n->next) { 4666 if (n->obj == NULL || 4667 (res = symlook_list(&req1, &n->obj->dagmembers, dlp)) != 0) 4668 continue; 4669 if (def == NULL || (ld_dynamic_weak && 4670 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4671 def = req1.sym_out; 4672 defobj = req1.defobj_out; 4673 if (!ld_dynamic_weak || ELF_ST_BIND(def->st_info) != STB_WEAK) 4674 break; 4675 } 4676 } 4677 if (def != NULL) { 4678 req->sym_out = def; 4679 req->defobj_out = defobj; 4680 return (0); 4681 } 4682 return (ESRCH); 4683 } 4684 4685 /* 4686 * Search the symbol table of a single shared object for a symbol of 4687 * the given name and version, if requested. Returns a pointer to the 4688 * symbol, or NULL if no definition was found. If the object is 4689 * filter, return filtered symbol from filtee. 4690 * 4691 * The symbol's hash value is passed in for efficiency reasons; that 4692 * eliminates many recomputations of the hash value. 4693 */ 4694 int 4695 symlook_obj(SymLook *req, const Obj_Entry *obj) 4696 { 4697 DoneList donelist; 4698 SymLook req1; 4699 int flags, res, mres; 4700 4701 /* 4702 * If there is at least one valid hash at this point, we prefer to 4703 * use the faster GNU version if available. 4704 */ 4705 if (obj->valid_hash_gnu) 4706 mres = symlook_obj1_gnu(req, obj); 4707 else if (obj->valid_hash_sysv) 4708 mres = symlook_obj1_sysv(req, obj); 4709 else 4710 return (EINVAL); 4711 4712 if (mres == 0) { 4713 if (obj->needed_filtees != NULL) { 4714 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; 4715 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 4716 donelist_init(&donelist); 4717 symlook_init_from_req(&req1, req); 4718 res = symlook_needed(&req1, obj->needed_filtees, &donelist); 4719 if (res == 0) { 4720 req->sym_out = req1.sym_out; 4721 req->defobj_out = req1.defobj_out; 4722 } 4723 return (res); 4724 } 4725 if (obj->needed_aux_filtees != NULL) { 4726 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; 4727 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 4728 donelist_init(&donelist); 4729 symlook_init_from_req(&req1, req); 4730 res = symlook_needed(&req1, obj->needed_aux_filtees, &donelist); 4731 if (res == 0) { 4732 req->sym_out = req1.sym_out; 4733 req->defobj_out = req1.defobj_out; 4734 return (res); 4735 } 4736 } 4737 } 4738 return (mres); 4739 } 4740 4741 /* Symbol match routine common to both hash functions */ 4742 static bool 4743 matched_symbol(SymLook *req, const Obj_Entry *obj, Sym_Match_Result *result, 4744 const unsigned long symnum) 4745 { 4746 Elf_Versym verndx; 4747 const Elf_Sym *symp; 4748 const char *strp; 4749 4750 symp = obj->symtab + symnum; 4751 strp = obj->strtab + symp->st_name; 4752 4753 switch (ELF_ST_TYPE(symp->st_info)) { 4754 case STT_FUNC: 4755 case STT_NOTYPE: 4756 case STT_OBJECT: 4757 case STT_COMMON: 4758 case STT_GNU_IFUNC: 4759 if (symp->st_value == 0) 4760 return (false); 4761 /* fallthrough */ 4762 case STT_TLS: 4763 if (symp->st_shndx != SHN_UNDEF) 4764 break; 4765 else if (((req->flags & SYMLOOK_IN_PLT) == 0) && 4766 (ELF_ST_TYPE(symp->st_info) == STT_FUNC)) 4767 break; 4768 /* fallthrough */ 4769 default: 4770 return (false); 4771 } 4772 if (req->name[0] != strp[0] || strcmp(req->name, strp) != 0) 4773 return (false); 4774 4775 if (req->ventry == NULL) { 4776 if (obj->versyms != NULL) { 4777 verndx = VER_NDX(obj->versyms[symnum]); 4778 if (verndx > obj->vernum) { 4779 _rtld_error( 4780 "%s: symbol %s references wrong version %d", 4781 obj->path, obj->strtab + symnum, verndx); 4782 return (false); 4783 } 4784 /* 4785 * If we are not called from dlsym (i.e. this 4786 * is a normal relocation from unversioned 4787 * binary), accept the symbol immediately if 4788 * it happens to have first version after this 4789 * shared object became versioned. Otherwise, 4790 * if symbol is versioned and not hidden, 4791 * remember it. If it is the only symbol with 4792 * this name exported by the shared object, it 4793 * will be returned as a match by the calling 4794 * function. If symbol is global (verndx < 2) 4795 * accept it unconditionally. 4796 */ 4797 if ((req->flags & SYMLOOK_DLSYM) == 0 && 4798 verndx == VER_NDX_GIVEN) { 4799 result->sym_out = symp; 4800 return (true); 4801 } 4802 else if (verndx >= VER_NDX_GIVEN) { 4803 if ((obj->versyms[symnum] & VER_NDX_HIDDEN) 4804 == 0) { 4805 if (result->vsymp == NULL) 4806 result->vsymp = symp; 4807 result->vcount++; 4808 } 4809 return (false); 4810 } 4811 } 4812 result->sym_out = symp; 4813 return (true); 4814 } 4815 if (obj->versyms == NULL) { 4816 if (object_match_name(obj, req->ventry->name)) { 4817 _rtld_error("%s: object %s should provide version %s " 4818 "for symbol %s", obj_rtld.path, obj->path, 4819 req->ventry->name, obj->strtab + symnum); 4820 return (false); 4821 } 4822 } else { 4823 verndx = VER_NDX(obj->versyms[symnum]); 4824 if (verndx > obj->vernum) { 4825 _rtld_error("%s: symbol %s references wrong version %d", 4826 obj->path, obj->strtab + symnum, verndx); 4827 return (false); 4828 } 4829 if (obj->vertab[verndx].hash != req->ventry->hash || 4830 strcmp(obj->vertab[verndx].name, req->ventry->name)) { 4831 /* 4832 * Version does not match. Look if this is a 4833 * global symbol and if it is not hidden. If 4834 * global symbol (verndx < 2) is available, 4835 * use it. Do not return symbol if we are 4836 * called by dlvsym, because dlvsym looks for 4837 * a specific version and default one is not 4838 * what dlvsym wants. 4839 */ 4840 if ((req->flags & SYMLOOK_DLSYM) || 4841 (verndx >= VER_NDX_GIVEN) || 4842 (obj->versyms[symnum] & VER_NDX_HIDDEN)) 4843 return (false); 4844 } 4845 } 4846 result->sym_out = symp; 4847 return (true); 4848 } 4849 4850 /* 4851 * Search for symbol using SysV hash function. 4852 * obj->buckets is known not to be NULL at this point; the test for this was 4853 * performed with the obj->valid_hash_sysv assignment. 4854 */ 4855 static int 4856 symlook_obj1_sysv(SymLook *req, const Obj_Entry *obj) 4857 { 4858 unsigned long symnum; 4859 Sym_Match_Result matchres; 4860 4861 matchres.sym_out = NULL; 4862 matchres.vsymp = NULL; 4863 matchres.vcount = 0; 4864 4865 for (symnum = obj->buckets[req->hash % obj->nbuckets]; 4866 symnum != STN_UNDEF; symnum = obj->chains[symnum]) { 4867 if (symnum >= obj->nchains) 4868 return (ESRCH); /* Bad object */ 4869 4870 if (matched_symbol(req, obj, &matchres, symnum)) { 4871 req->sym_out = matchres.sym_out; 4872 req->defobj_out = obj; 4873 return (0); 4874 } 4875 } 4876 if (matchres.vcount == 1) { 4877 req->sym_out = matchres.vsymp; 4878 req->defobj_out = obj; 4879 return (0); 4880 } 4881 return (ESRCH); 4882 } 4883 4884 /* Search for symbol using GNU hash function */ 4885 static int 4886 symlook_obj1_gnu(SymLook *req, const Obj_Entry *obj) 4887 { 4888 Elf_Addr bloom_word; 4889 const Elf32_Word *hashval; 4890 Elf32_Word bucket; 4891 Sym_Match_Result matchres; 4892 unsigned int h1, h2; 4893 unsigned long symnum; 4894 4895 matchres.sym_out = NULL; 4896 matchres.vsymp = NULL; 4897 matchres.vcount = 0; 4898 4899 /* Pick right bitmask word from Bloom filter array */ 4900 bloom_word = obj->bloom_gnu[(req->hash_gnu / __ELF_WORD_SIZE) & 4901 obj->maskwords_bm_gnu]; 4902 4903 /* Calculate modulus word size of gnu hash and its derivative */ 4904 h1 = req->hash_gnu & (__ELF_WORD_SIZE - 1); 4905 h2 = ((req->hash_gnu >> obj->shift2_gnu) & (__ELF_WORD_SIZE - 1)); 4906 4907 /* Filter out the "definitely not in set" queries */ 4908 if (((bloom_word >> h1) & (bloom_word >> h2) & 1) == 0) 4909 return (ESRCH); 4910 4911 /* Locate hash chain and corresponding value element*/ 4912 bucket = obj->buckets_gnu[req->hash_gnu % obj->nbuckets_gnu]; 4913 if (bucket == 0) 4914 return (ESRCH); 4915 hashval = &obj->chain_zero_gnu[bucket]; 4916 do { 4917 if (((*hashval ^ req->hash_gnu) >> 1) == 0) { 4918 symnum = hashval - obj->chain_zero_gnu; 4919 if (matched_symbol(req, obj, &matchres, symnum)) { 4920 req->sym_out = matchres.sym_out; 4921 req->defobj_out = obj; 4922 return (0); 4923 } 4924 } 4925 } while ((*hashval++ & 1) == 0); 4926 if (matchres.vcount == 1) { 4927 req->sym_out = matchres.vsymp; 4928 req->defobj_out = obj; 4929 return (0); 4930 } 4931 return (ESRCH); 4932 } 4933 4934 static void 4935 trace_calc_fmts(const char **main_local, const char **fmt1, const char **fmt2) 4936 { 4937 *main_local = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_PROGNAME); 4938 if (*main_local == NULL) 4939 *main_local = ""; 4940 4941 *fmt1 = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_FMT1); 4942 if (*fmt1 == NULL) 4943 *fmt1 = "\t%o => %p (%x)\n"; 4944 4945 *fmt2 = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_FMT2); 4946 if (*fmt2 == NULL) 4947 *fmt2 = "\t%o (%x)\n"; 4948 } 4949 4950 static void 4951 trace_print_obj(Obj_Entry *obj, const char *name, const char *path, 4952 const char *main_local, const char *fmt1, const char *fmt2) 4953 { 4954 const char *fmt; 4955 int c; 4956 4957 if (fmt1 == NULL) 4958 fmt = fmt2; 4959 else 4960 /* XXX bogus */ 4961 fmt = strncmp(name, "lib", 3) == 0 ? fmt1 : fmt2; 4962 4963 while ((c = *fmt++) != '\0') { 4964 switch (c) { 4965 default: 4966 rtld_putchar(c); 4967 continue; 4968 case '\\': 4969 switch (c = *fmt) { 4970 case '\0': 4971 continue; 4972 case 'n': 4973 rtld_putchar('\n'); 4974 break; 4975 case 't': 4976 rtld_putchar('\t'); 4977 break; 4978 } 4979 break; 4980 case '%': 4981 switch (c = *fmt) { 4982 case '\0': 4983 continue; 4984 case '%': 4985 default: 4986 rtld_putchar(c); 4987 break; 4988 case 'A': 4989 rtld_putstr(main_local); 4990 break; 4991 case 'a': 4992 rtld_putstr(obj_main->path); 4993 break; 4994 case 'o': 4995 rtld_putstr(name); 4996 break; 4997 case 'p': 4998 rtld_putstr(path); 4999 break; 5000 case 'x': 5001 rtld_printf("%p", obj != NULL ? 5002 obj->mapbase : NULL); 5003 break; 5004 } 5005 break; 5006 } 5007 ++fmt; 5008 } 5009 } 5010 5011 static void 5012 trace_loaded_objects(Obj_Entry *obj, bool show_preload) 5013 { 5014 const char *fmt1, *fmt2, *main_local; 5015 const char *name, *path; 5016 bool first_spurious, list_containers; 5017 5018 trace_calc_fmts(&main_local, &fmt1, &fmt2); 5019 list_containers = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_ALL) != NULL; 5020 5021 for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 5022 Needed_Entry *needed; 5023 5024 if (obj->marker) 5025 continue; 5026 if (list_containers && obj->needed != NULL) 5027 rtld_printf("%s:\n", obj->path); 5028 for (needed = obj->needed; needed; needed = needed->next) { 5029 if (needed->obj != NULL) { 5030 if (needed->obj->traced && !list_containers) 5031 continue; 5032 needed->obj->traced = true; 5033 path = needed->obj->path; 5034 } else 5035 path = "not found"; 5036 5037 name = obj->strtab + needed->name; 5038 trace_print_obj(needed->obj, name, path, main_local, 5039 fmt1, fmt2); 5040 } 5041 } 5042 5043 if (show_preload) { 5044 if (ld_get_env_var(LD_TRACE_LOADED_OBJECTS_FMT2) == NULL) 5045 fmt2 = "\t%p (%x)\n"; 5046 first_spurious = true; 5047 5048 TAILQ_FOREACH(obj, &obj_list, next) { 5049 if (obj->marker || obj == obj_main || obj->traced) 5050 continue; 5051 5052 if (list_containers && first_spurious) { 5053 rtld_printf("[preloaded]\n"); 5054 first_spurious = false; 5055 } 5056 5057 Name_Entry *fname = STAILQ_FIRST(&obj->names); 5058 name = fname == NULL ? "<unknown>" : fname->name; 5059 trace_print_obj(obj, name, obj->path, main_local, 5060 NULL, fmt2); 5061 } 5062 } 5063 } 5064 5065 /* 5066 * Unload a dlopened object and its dependencies from memory and from 5067 * our data structures. It is assumed that the DAG rooted in the 5068 * object has already been unreferenced, and that the object has a 5069 * reference count of 0. 5070 */ 5071 static void 5072 unload_object(Obj_Entry *root, RtldLockState *lockstate) 5073 { 5074 Obj_Entry marker, *obj, *next; 5075 5076 assert(root->refcount == 0); 5077 5078 /* 5079 * Pass over the DAG removing unreferenced objects from 5080 * appropriate lists. 5081 */ 5082 unlink_object(root); 5083 5084 /* Unmap all objects that are no longer referenced. */ 5085 for (obj = TAILQ_FIRST(&obj_list); obj != NULL; obj = next) { 5086 next = TAILQ_NEXT(obj, next); 5087 if (obj->marker || obj->refcount != 0) 5088 continue; 5089 LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase, 5090 obj->mapsize, 0, obj->path); 5091 dbg("unloading \"%s\"", obj->path); 5092 /* 5093 * Unlink the object now to prevent new references from 5094 * being acquired while the bind lock is dropped in 5095 * recursive dlclose() invocations. 5096 */ 5097 TAILQ_REMOVE(&obj_list, obj, next); 5098 obj_count--; 5099 5100 if (obj->filtees_loaded) { 5101 if (next != NULL) { 5102 init_marker(&marker); 5103 TAILQ_INSERT_BEFORE(next, &marker, next); 5104 unload_filtees(obj, lockstate); 5105 next = TAILQ_NEXT(&marker, next); 5106 TAILQ_REMOVE(&obj_list, &marker, next); 5107 } else 5108 unload_filtees(obj, lockstate); 5109 } 5110 release_object(obj); 5111 } 5112 } 5113 5114 static void 5115 unlink_object(Obj_Entry *root) 5116 { 5117 Objlist_Entry *elm; 5118 5119 if (root->refcount == 0) { 5120 /* Remove the object from the RTLD_GLOBAL list. */ 5121 objlist_remove(&list_global, root); 5122 5123 /* Remove the object from all objects' DAG lists. */ 5124 STAILQ_FOREACH(elm, &root->dagmembers, link) { 5125 objlist_remove(&elm->obj->dldags, root); 5126 if (elm->obj != root) 5127 unlink_object(elm->obj); 5128 } 5129 } 5130 } 5131 5132 static void 5133 ref_dag(Obj_Entry *root) 5134 { 5135 Objlist_Entry *elm; 5136 5137 assert(root->dag_inited); 5138 STAILQ_FOREACH(elm, &root->dagmembers, link) 5139 elm->obj->refcount++; 5140 } 5141 5142 static void 5143 unref_dag(Obj_Entry *root) 5144 { 5145 Objlist_Entry *elm; 5146 5147 assert(root->dag_inited); 5148 STAILQ_FOREACH(elm, &root->dagmembers, link) 5149 elm->obj->refcount--; 5150 } 5151 5152 /* 5153 * Common code for MD __tls_get_addr(). 5154 */ 5155 static void * 5156 tls_get_addr_slow(Elf_Addr **dtvp, int index, size_t offset, bool locked) 5157 { 5158 Elf_Addr *newdtv, *dtv; 5159 RtldLockState lockstate; 5160 int to_copy; 5161 5162 dtv = *dtvp; 5163 /* Check dtv generation in case new modules have arrived */ 5164 if (dtv[0] != tls_dtv_generation) { 5165 if (!locked) 5166 wlock_acquire(rtld_bind_lock, &lockstate); 5167 newdtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 5168 to_copy = dtv[1]; 5169 if (to_copy > tls_max_index) 5170 to_copy = tls_max_index; 5171 memcpy(&newdtv[2], &dtv[2], to_copy * sizeof(Elf_Addr)); 5172 newdtv[0] = tls_dtv_generation; 5173 newdtv[1] = tls_max_index; 5174 free(dtv); 5175 if (!locked) 5176 lock_release(rtld_bind_lock, &lockstate); 5177 dtv = *dtvp = newdtv; 5178 } 5179 5180 /* Dynamically allocate module TLS if necessary */ 5181 if (dtv[index + 1] == 0) { 5182 /* Signal safe, wlock will block out signals. */ 5183 if (!locked) 5184 wlock_acquire(rtld_bind_lock, &lockstate); 5185 if (!dtv[index + 1]) 5186 dtv[index + 1] = (Elf_Addr)allocate_module_tls(index); 5187 if (!locked) 5188 lock_release(rtld_bind_lock, &lockstate); 5189 } 5190 return ((void *)(dtv[index + 1] + offset)); 5191 } 5192 5193 void * 5194 tls_get_addr_common(uintptr_t **dtvp, int index, size_t offset) 5195 { 5196 uintptr_t *dtv; 5197 5198 dtv = *dtvp; 5199 /* Check dtv generation in case new modules have arrived */ 5200 if (__predict_true(dtv[0] == tls_dtv_generation && 5201 dtv[index + 1] != 0)) 5202 return ((void *)(dtv[index + 1] + offset)); 5203 return (tls_get_addr_slow(dtvp, index, offset, false)); 5204 } 5205 5206 #ifdef TLS_VARIANT_I 5207 5208 /* 5209 * Return pointer to allocated TLS block 5210 */ 5211 static void * 5212 get_tls_block_ptr(void *tcb, size_t tcbsize) 5213 { 5214 size_t extra_size, post_size, pre_size, tls_block_size; 5215 size_t tls_init_align; 5216 5217 tls_init_align = MAX(obj_main->tlsalign, 1); 5218 5219 /* Compute fragments sizes. */ 5220 extra_size = tcbsize - TLS_TCB_SIZE; 5221 post_size = calculate_tls_post_size(tls_init_align); 5222 tls_block_size = tcbsize + post_size; 5223 pre_size = roundup2(tls_block_size, tls_init_align) - tls_block_size; 5224 5225 return ((char *)tcb - pre_size - extra_size); 5226 } 5227 5228 /* 5229 * Allocate Static TLS using the Variant I method. 5230 * 5231 * For details on the layout, see lib/libc/gen/tls.c. 5232 * 5233 * NB: rtld's tls_static_space variable includes TLS_TCB_SIZE and post_size as 5234 * it is based on tls_last_offset, and TLS offsets here are really TCB 5235 * offsets, whereas libc's tls_static_space is just the executable's static 5236 * TLS segment. 5237 */ 5238 void * 5239 allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign) 5240 { 5241 Obj_Entry *obj; 5242 char *tls_block; 5243 Elf_Addr *dtv, **tcb; 5244 Elf_Addr addr; 5245 Elf_Addr i; 5246 size_t extra_size, maxalign, post_size, pre_size, tls_block_size; 5247 size_t tls_init_align, tls_init_offset; 5248 5249 if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE) 5250 return (oldtcb); 5251 5252 assert(tcbsize >= TLS_TCB_SIZE); 5253 maxalign = MAX(tcbalign, tls_static_max_align); 5254 tls_init_align = MAX(obj_main->tlsalign, 1); 5255 5256 /* Compute fragmets sizes. */ 5257 extra_size = tcbsize - TLS_TCB_SIZE; 5258 post_size = calculate_tls_post_size(tls_init_align); 5259 tls_block_size = tcbsize + post_size; 5260 pre_size = roundup2(tls_block_size, tls_init_align) - tls_block_size; 5261 tls_block_size += pre_size + tls_static_space - TLS_TCB_SIZE - post_size; 5262 5263 /* Allocate whole TLS block */ 5264 tls_block = malloc_aligned(tls_block_size, maxalign, 0); 5265 tcb = (Elf_Addr **)(tls_block + pre_size + extra_size); 5266 5267 if (oldtcb != NULL) { 5268 memcpy(tls_block, get_tls_block_ptr(oldtcb, tcbsize), 5269 tls_static_space); 5270 free_aligned(get_tls_block_ptr(oldtcb, tcbsize)); 5271 5272 /* Adjust the DTV. */ 5273 dtv = tcb[0]; 5274 for (i = 0; i < dtv[1]; i++) { 5275 if (dtv[i+2] >= (Elf_Addr)oldtcb && 5276 dtv[i+2] < (Elf_Addr)oldtcb + tls_static_space) { 5277 dtv[i+2] = dtv[i+2] - (Elf_Addr)oldtcb + (Elf_Addr)tcb; 5278 } 5279 } 5280 } else { 5281 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 5282 tcb[0] = dtv; 5283 dtv[0] = tls_dtv_generation; 5284 dtv[1] = tls_max_index; 5285 5286 for (obj = globallist_curr(objs); obj != NULL; 5287 obj = globallist_next(obj)) { 5288 if (obj->tlsoffset == 0) 5289 continue; 5290 tls_init_offset = obj->tlspoffset & (obj->tlsalign - 1); 5291 addr = (Elf_Addr)tcb + obj->tlsoffset; 5292 if (tls_init_offset > 0) 5293 memset((void *)addr, 0, tls_init_offset); 5294 if (obj->tlsinitsize > 0) { 5295 memcpy((void *)(addr + tls_init_offset), obj->tlsinit, 5296 obj->tlsinitsize); 5297 } 5298 if (obj->tlssize > obj->tlsinitsize) { 5299 memset((void *)(addr + tls_init_offset + obj->tlsinitsize), 5300 0, obj->tlssize - obj->tlsinitsize - tls_init_offset); 5301 } 5302 dtv[obj->tlsindex + 1] = addr; 5303 } 5304 } 5305 5306 return (tcb); 5307 } 5308 5309 void 5310 free_tls(void *tcb, size_t tcbsize, size_t tcbalign __unused) 5311 { 5312 Elf_Addr *dtv; 5313 Elf_Addr tlsstart, tlsend; 5314 size_t post_size; 5315 size_t dtvsize, i, tls_init_align; 5316 5317 assert(tcbsize >= TLS_TCB_SIZE); 5318 tls_init_align = MAX(obj_main->tlsalign, 1); 5319 5320 /* Compute fragments sizes. */ 5321 post_size = calculate_tls_post_size(tls_init_align); 5322 5323 tlsstart = (Elf_Addr)tcb + TLS_TCB_SIZE + post_size; 5324 tlsend = (Elf_Addr)tcb + tls_static_space; 5325 5326 dtv = *(Elf_Addr **)tcb; 5327 dtvsize = dtv[1]; 5328 for (i = 0; i < dtvsize; i++) { 5329 if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] >= tlsend)) { 5330 free((void*)dtv[i+2]); 5331 } 5332 } 5333 free(dtv); 5334 free_aligned(get_tls_block_ptr(tcb, tcbsize)); 5335 } 5336 5337 #endif /* TLS_VARIANT_I */ 5338 5339 #ifdef TLS_VARIANT_II 5340 5341 /* 5342 * Allocate Static TLS using the Variant II method. 5343 */ 5344 void * 5345 allocate_tls(Obj_Entry *objs, void *oldtls, size_t tcbsize, size_t tcbalign) 5346 { 5347 Obj_Entry *obj; 5348 size_t size, ralign; 5349 char *tls; 5350 Elf_Addr *dtv, *olddtv; 5351 Elf_Addr segbase, oldsegbase, addr; 5352 size_t i; 5353 5354 ralign = tcbalign; 5355 if (tls_static_max_align > ralign) 5356 ralign = tls_static_max_align; 5357 size = roundup(tls_static_space, ralign) + roundup(tcbsize, ralign); 5358 5359 assert(tcbsize >= 2*sizeof(Elf_Addr)); 5360 tls = malloc_aligned(size, ralign, 0 /* XXX */); 5361 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 5362 5363 segbase = (Elf_Addr)(tls + roundup(tls_static_space, ralign)); 5364 ((Elf_Addr *)segbase)[0] = segbase; 5365 ((Elf_Addr *)segbase)[1] = (Elf_Addr) dtv; 5366 5367 dtv[0] = tls_dtv_generation; 5368 dtv[1] = tls_max_index; 5369 5370 if (oldtls) { 5371 /* 5372 * Copy the static TLS block over whole. 5373 */ 5374 oldsegbase = (Elf_Addr) oldtls; 5375 memcpy((void *)(segbase - tls_static_space), 5376 (const void *)(oldsegbase - tls_static_space), 5377 tls_static_space); 5378 5379 /* 5380 * If any dynamic TLS blocks have been created tls_get_addr(), 5381 * move them over. 5382 */ 5383 olddtv = ((Elf_Addr **)oldsegbase)[1]; 5384 for (i = 0; i < olddtv[1]; i++) { 5385 if (olddtv[i + 2] < oldsegbase - size || 5386 olddtv[i + 2] > oldsegbase) { 5387 dtv[i + 2] = olddtv[i + 2]; 5388 olddtv[i + 2] = 0; 5389 } 5390 } 5391 5392 /* 5393 * We assume that this block was the one we created with 5394 * allocate_initial_tls(). 5395 */ 5396 free_tls(oldtls, 2 * sizeof(Elf_Addr), sizeof(Elf_Addr)); 5397 } else { 5398 for (obj = objs; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 5399 if (obj->marker || obj->tlsoffset == 0) 5400 continue; 5401 addr = segbase - obj->tlsoffset; 5402 memset((void *)(addr + obj->tlsinitsize), 5403 0, obj->tlssize - obj->tlsinitsize); 5404 if (obj->tlsinit) { 5405 memcpy((void *)addr, obj->tlsinit, obj->tlsinitsize); 5406 obj->static_tls_copied = true; 5407 } 5408 dtv[obj->tlsindex + 1] = addr; 5409 } 5410 } 5411 5412 return ((void *)segbase); 5413 } 5414 5415 void 5416 free_tls(void *tls, size_t tcbsize __unused, size_t tcbalign) 5417 { 5418 Elf_Addr* dtv; 5419 size_t size, ralign; 5420 int dtvsize, i; 5421 Elf_Addr tlsstart, tlsend; 5422 5423 /* 5424 * Figure out the size of the initial TLS block so that we can 5425 * find stuff which ___tls_get_addr() allocated dynamically. 5426 */ 5427 ralign = tcbalign; 5428 if (tls_static_max_align > ralign) 5429 ralign = tls_static_max_align; 5430 size = roundup(tls_static_space, ralign); 5431 5432 dtv = ((Elf_Addr **)tls)[1]; 5433 dtvsize = dtv[1]; 5434 tlsend = (Elf_Addr)tls; 5435 tlsstart = tlsend - size; 5436 for (i = 0; i < dtvsize; i++) { 5437 if (dtv[i + 2] != 0 && (dtv[i + 2] < tlsstart || 5438 dtv[i + 2] > tlsend)) { 5439 free_aligned((void *)dtv[i + 2]); 5440 } 5441 } 5442 5443 free_aligned((void *)tlsstart); 5444 free((void *)dtv); 5445 } 5446 5447 #endif /* TLS_VARIANT_II */ 5448 5449 /* 5450 * Allocate TLS block for module with given index. 5451 */ 5452 void * 5453 allocate_module_tls(int index) 5454 { 5455 Obj_Entry *obj; 5456 char *p; 5457 5458 TAILQ_FOREACH(obj, &obj_list, next) { 5459 if (obj->marker) 5460 continue; 5461 if (obj->tlsindex == index) 5462 break; 5463 } 5464 if (obj == NULL) { 5465 _rtld_error("Can't find module with TLS index %d", index); 5466 rtld_die(); 5467 } 5468 5469 p = malloc_aligned(obj->tlssize, obj->tlsalign, obj->tlspoffset); 5470 memcpy(p, obj->tlsinit, obj->tlsinitsize); 5471 memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize); 5472 return (p); 5473 } 5474 5475 bool 5476 allocate_tls_offset(Obj_Entry *obj) 5477 { 5478 size_t off; 5479 5480 if (obj->tls_done) 5481 return (true); 5482 5483 if (obj->tlssize == 0) { 5484 obj->tls_done = true; 5485 return (true); 5486 } 5487 5488 if (tls_last_offset == 0) 5489 off = calculate_first_tls_offset(obj->tlssize, obj->tlsalign, 5490 obj->tlspoffset); 5491 else 5492 off = calculate_tls_offset(tls_last_offset, tls_last_size, 5493 obj->tlssize, obj->tlsalign, obj->tlspoffset); 5494 5495 obj->tlsoffset = off; 5496 #ifdef TLS_VARIANT_I 5497 off += obj->tlssize; 5498 #endif 5499 5500 /* 5501 * If we have already fixed the size of the static TLS block, we 5502 * must stay within that size. When allocating the static TLS, we 5503 * leave a small amount of space spare to be used for dynamically 5504 * loading modules which use static TLS. 5505 */ 5506 if (tls_static_space != 0) { 5507 if (off > tls_static_space) 5508 return (false); 5509 } else if (obj->tlsalign > tls_static_max_align) { 5510 tls_static_max_align = obj->tlsalign; 5511 } 5512 5513 tls_last_offset = off; 5514 tls_last_size = obj->tlssize; 5515 obj->tls_done = true; 5516 5517 return (true); 5518 } 5519 5520 void 5521 free_tls_offset(Obj_Entry *obj) 5522 { 5523 5524 /* 5525 * If we were the last thing to allocate out of the static TLS 5526 * block, we give our space back to the 'allocator'. This is a 5527 * simplistic workaround to allow libGL.so.1 to be loaded and 5528 * unloaded multiple times. 5529 */ 5530 size_t off = obj->tlsoffset; 5531 #ifdef TLS_VARIANT_I 5532 off += obj->tlssize; 5533 #endif 5534 if (off == tls_last_offset) { 5535 tls_last_offset -= obj->tlssize; 5536 tls_last_size = 0; 5537 } 5538 } 5539 5540 void * 5541 _rtld_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign) 5542 { 5543 void *ret; 5544 RtldLockState lockstate; 5545 5546 wlock_acquire(rtld_bind_lock, &lockstate); 5547 ret = allocate_tls(globallist_curr(TAILQ_FIRST(&obj_list)), oldtls, 5548 tcbsize, tcbalign); 5549 lock_release(rtld_bind_lock, &lockstate); 5550 return (ret); 5551 } 5552 5553 void 5554 _rtld_free_tls(void *tcb, size_t tcbsize, size_t tcbalign) 5555 { 5556 RtldLockState lockstate; 5557 5558 wlock_acquire(rtld_bind_lock, &lockstate); 5559 free_tls(tcb, tcbsize, tcbalign); 5560 lock_release(rtld_bind_lock, &lockstate); 5561 } 5562 5563 static void 5564 object_add_name(Obj_Entry *obj, const char *name) 5565 { 5566 Name_Entry *entry; 5567 size_t len; 5568 5569 len = strlen(name); 5570 entry = malloc(sizeof(Name_Entry) + len); 5571 5572 if (entry != NULL) { 5573 strcpy(entry->name, name); 5574 STAILQ_INSERT_TAIL(&obj->names, entry, link); 5575 } 5576 } 5577 5578 static int 5579 object_match_name(const Obj_Entry *obj, const char *name) 5580 { 5581 Name_Entry *entry; 5582 5583 STAILQ_FOREACH(entry, &obj->names, link) { 5584 if (strcmp(name, entry->name) == 0) 5585 return (1); 5586 } 5587 return (0); 5588 } 5589 5590 static Obj_Entry * 5591 locate_dependency(const Obj_Entry *obj, const char *name) 5592 { 5593 const Objlist_Entry *entry; 5594 const Needed_Entry *needed; 5595 5596 STAILQ_FOREACH(entry, &list_main, link) { 5597 if (object_match_name(entry->obj, name)) 5598 return (entry->obj); 5599 } 5600 5601 for (needed = obj->needed; needed != NULL; needed = needed->next) { 5602 if (strcmp(obj->strtab + needed->name, name) == 0 || 5603 (needed->obj != NULL && object_match_name(needed->obj, name))) { 5604 /* 5605 * If there is DT_NEEDED for the name we are looking for, 5606 * we are all set. Note that object might not be found if 5607 * dependency was not loaded yet, so the function can 5608 * return NULL here. This is expected and handled 5609 * properly by the caller. 5610 */ 5611 return (needed->obj); 5612 } 5613 } 5614 _rtld_error("%s: Unexpected inconsistency: dependency %s not found", 5615 obj->path, name); 5616 rtld_die(); 5617 } 5618 5619 static int 5620 check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj, 5621 const Elf_Vernaux *vna) 5622 { 5623 const Elf_Verdef *vd; 5624 const char *vername; 5625 5626 vername = refobj->strtab + vna->vna_name; 5627 vd = depobj->verdef; 5628 if (vd == NULL) { 5629 _rtld_error("%s: version %s required by %s not defined", 5630 depobj->path, vername, refobj->path); 5631 return (-1); 5632 } 5633 for (;;) { 5634 if (vd->vd_version != VER_DEF_CURRENT) { 5635 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 5636 depobj->path, vd->vd_version); 5637 return (-1); 5638 } 5639 if (vna->vna_hash == vd->vd_hash) { 5640 const Elf_Verdaux *aux = (const Elf_Verdaux *) 5641 ((const char *)vd + vd->vd_aux); 5642 if (strcmp(vername, depobj->strtab + aux->vda_name) == 0) 5643 return (0); 5644 } 5645 if (vd->vd_next == 0) 5646 break; 5647 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 5648 } 5649 if (vna->vna_flags & VER_FLG_WEAK) 5650 return (0); 5651 _rtld_error("%s: version %s required by %s not found", 5652 depobj->path, vername, refobj->path); 5653 return (-1); 5654 } 5655 5656 static int 5657 rtld_verify_object_versions(Obj_Entry *obj) 5658 { 5659 const Elf_Verneed *vn; 5660 const Elf_Verdef *vd; 5661 const Elf_Verdaux *vda; 5662 const Elf_Vernaux *vna; 5663 const Obj_Entry *depobj; 5664 int maxvernum, vernum; 5665 5666 if (obj->ver_checked) 5667 return (0); 5668 obj->ver_checked = true; 5669 5670 maxvernum = 0; 5671 /* 5672 * Walk over defined and required version records and figure out 5673 * max index used by any of them. Do very basic sanity checking 5674 * while there. 5675 */ 5676 vn = obj->verneed; 5677 while (vn != NULL) { 5678 if (vn->vn_version != VER_NEED_CURRENT) { 5679 _rtld_error("%s: Unsupported version %d of Elf_Verneed entry", 5680 obj->path, vn->vn_version); 5681 return (-1); 5682 } 5683 vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux); 5684 for (;;) { 5685 vernum = VER_NEED_IDX(vna->vna_other); 5686 if (vernum > maxvernum) 5687 maxvernum = vernum; 5688 if (vna->vna_next == 0) 5689 break; 5690 vna = (const Elf_Vernaux *)((const char *)vna + vna->vna_next); 5691 } 5692 if (vn->vn_next == 0) 5693 break; 5694 vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next); 5695 } 5696 5697 vd = obj->verdef; 5698 while (vd != NULL) { 5699 if (vd->vd_version != VER_DEF_CURRENT) { 5700 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 5701 obj->path, vd->vd_version); 5702 return (-1); 5703 } 5704 vernum = VER_DEF_IDX(vd->vd_ndx); 5705 if (vernum > maxvernum) 5706 maxvernum = vernum; 5707 if (vd->vd_next == 0) 5708 break; 5709 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 5710 } 5711 5712 if (maxvernum == 0) 5713 return (0); 5714 5715 /* 5716 * Store version information in array indexable by version index. 5717 * Verify that object version requirements are satisfied along the 5718 * way. 5719 */ 5720 obj->vernum = maxvernum + 1; 5721 obj->vertab = xcalloc(obj->vernum, sizeof(Ver_Entry)); 5722 5723 vd = obj->verdef; 5724 while (vd != NULL) { 5725 if ((vd->vd_flags & VER_FLG_BASE) == 0) { 5726 vernum = VER_DEF_IDX(vd->vd_ndx); 5727 assert(vernum <= maxvernum); 5728 vda = (const Elf_Verdaux *)((const char *)vd + vd->vd_aux); 5729 obj->vertab[vernum].hash = vd->vd_hash; 5730 obj->vertab[vernum].name = obj->strtab + vda->vda_name; 5731 obj->vertab[vernum].file = NULL; 5732 obj->vertab[vernum].flags = 0; 5733 } 5734 if (vd->vd_next == 0) 5735 break; 5736 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 5737 } 5738 5739 vn = obj->verneed; 5740 while (vn != NULL) { 5741 depobj = locate_dependency(obj, obj->strtab + vn->vn_file); 5742 if (depobj == NULL) 5743 return (-1); 5744 vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux); 5745 for (;;) { 5746 if (check_object_provided_version(obj, depobj, vna)) 5747 return (-1); 5748 vernum = VER_NEED_IDX(vna->vna_other); 5749 assert(vernum <= maxvernum); 5750 obj->vertab[vernum].hash = vna->vna_hash; 5751 obj->vertab[vernum].name = obj->strtab + vna->vna_name; 5752 obj->vertab[vernum].file = obj->strtab + vn->vn_file; 5753 obj->vertab[vernum].flags = (vna->vna_other & VER_NEED_HIDDEN) ? 5754 VER_INFO_HIDDEN : 0; 5755 if (vna->vna_next == 0) 5756 break; 5757 vna = (const Elf_Vernaux *)((const char *)vna + vna->vna_next); 5758 } 5759 if (vn->vn_next == 0) 5760 break; 5761 vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next); 5762 } 5763 return (0); 5764 } 5765 5766 static int 5767 rtld_verify_versions(const Objlist *objlist) 5768 { 5769 Objlist_Entry *entry; 5770 int rc; 5771 5772 rc = 0; 5773 STAILQ_FOREACH(entry, objlist, link) { 5774 /* 5775 * Skip dummy objects or objects that have their version requirements 5776 * already checked. 5777 */ 5778 if (entry->obj->strtab == NULL || entry->obj->vertab != NULL) 5779 continue; 5780 if (rtld_verify_object_versions(entry->obj) == -1) { 5781 rc = -1; 5782 if (ld_tracing == NULL) 5783 break; 5784 } 5785 } 5786 if (rc == 0 || ld_tracing != NULL) 5787 rc = rtld_verify_object_versions(&obj_rtld); 5788 return (rc); 5789 } 5790 5791 const Ver_Entry * 5792 fetch_ventry(const Obj_Entry *obj, unsigned long symnum) 5793 { 5794 Elf_Versym vernum; 5795 5796 if (obj->vertab) { 5797 vernum = VER_NDX(obj->versyms[symnum]); 5798 if (vernum >= obj->vernum) { 5799 _rtld_error("%s: symbol %s has wrong verneed value %d", 5800 obj->path, obj->strtab + symnum, vernum); 5801 } else if (obj->vertab[vernum].hash != 0) { 5802 return (&obj->vertab[vernum]); 5803 } 5804 } 5805 return (NULL); 5806 } 5807 5808 int 5809 _rtld_get_stack_prot(void) 5810 { 5811 5812 return (stack_prot); 5813 } 5814 5815 int 5816 _rtld_is_dlopened(void *arg) 5817 { 5818 Obj_Entry *obj; 5819 RtldLockState lockstate; 5820 int res; 5821 5822 rlock_acquire(rtld_bind_lock, &lockstate); 5823 obj = dlcheck(arg); 5824 if (obj == NULL) 5825 obj = obj_from_addr(arg); 5826 if (obj == NULL) { 5827 _rtld_error("No shared object contains address"); 5828 lock_release(rtld_bind_lock, &lockstate); 5829 return (-1); 5830 } 5831 res = obj->dlopened ? 1 : 0; 5832 lock_release(rtld_bind_lock, &lockstate); 5833 return (res); 5834 } 5835 5836 static int 5837 obj_remap_relro(Obj_Entry *obj, int prot) 5838 { 5839 5840 if (obj->relro_size > 0 && mprotect(obj->relro_page, obj->relro_size, 5841 prot) == -1) { 5842 _rtld_error("%s: Cannot set relro protection to %#x: %s", 5843 obj->path, prot, rtld_strerror(errno)); 5844 return (-1); 5845 } 5846 return (0); 5847 } 5848 5849 static int 5850 obj_disable_relro(Obj_Entry *obj) 5851 { 5852 5853 return (obj_remap_relro(obj, PROT_READ | PROT_WRITE)); 5854 } 5855 5856 static int 5857 obj_enforce_relro(Obj_Entry *obj) 5858 { 5859 5860 return (obj_remap_relro(obj, PROT_READ)); 5861 } 5862 5863 static void 5864 map_stacks_exec(RtldLockState *lockstate) 5865 { 5866 void (*thr_map_stacks_exec)(void); 5867 5868 if ((max_stack_flags & PF_X) == 0 || (stack_prot & PROT_EXEC) != 0) 5869 return; 5870 thr_map_stacks_exec = (void (*)(void))(uintptr_t) 5871 get_program_var_addr("__pthread_map_stacks_exec", lockstate); 5872 if (thr_map_stacks_exec != NULL) { 5873 stack_prot |= PROT_EXEC; 5874 thr_map_stacks_exec(); 5875 } 5876 } 5877 5878 static void 5879 distribute_static_tls(Objlist *list, RtldLockState *lockstate) 5880 { 5881 Objlist_Entry *elm; 5882 Obj_Entry *obj; 5883 void (*distrib)(size_t, void *, size_t, size_t); 5884 5885 distrib = (void (*)(size_t, void *, size_t, size_t))(uintptr_t) 5886 get_program_var_addr("__pthread_distribute_static_tls", lockstate); 5887 if (distrib == NULL) 5888 return; 5889 STAILQ_FOREACH(elm, list, link) { 5890 obj = elm->obj; 5891 if (obj->marker || !obj->tls_done || obj->static_tls_copied) 5892 continue; 5893 distrib(obj->tlsoffset, obj->tlsinit, obj->tlsinitsize, 5894 obj->tlssize); 5895 obj->static_tls_copied = true; 5896 } 5897 } 5898 5899 void 5900 symlook_init(SymLook *dst, const char *name) 5901 { 5902 5903 bzero(dst, sizeof(*dst)); 5904 dst->name = name; 5905 dst->hash = elf_hash(name); 5906 dst->hash_gnu = gnu_hash(name); 5907 } 5908 5909 static void 5910 symlook_init_from_req(SymLook *dst, const SymLook *src) 5911 { 5912 5913 dst->name = src->name; 5914 dst->hash = src->hash; 5915 dst->hash_gnu = src->hash_gnu; 5916 dst->ventry = src->ventry; 5917 dst->flags = src->flags; 5918 dst->defobj_out = NULL; 5919 dst->sym_out = NULL; 5920 dst->lockstate = src->lockstate; 5921 } 5922 5923 static int 5924 open_binary_fd(const char *argv0, bool search_in_path, 5925 const char **binpath_res) 5926 { 5927 char *binpath, *pathenv, *pe, *res1; 5928 const char *res; 5929 int fd; 5930 5931 binpath = NULL; 5932 res = NULL; 5933 if (search_in_path && strchr(argv0, '/') == NULL) { 5934 binpath = xmalloc(PATH_MAX); 5935 pathenv = getenv("PATH"); 5936 if (pathenv == NULL) { 5937 _rtld_error("-p and no PATH environment variable"); 5938 rtld_die(); 5939 } 5940 pathenv = strdup(pathenv); 5941 if (pathenv == NULL) { 5942 _rtld_error("Cannot allocate memory"); 5943 rtld_die(); 5944 } 5945 fd = -1; 5946 errno = ENOENT; 5947 while ((pe = strsep(&pathenv, ":")) != NULL) { 5948 if (strlcpy(binpath, pe, PATH_MAX) >= PATH_MAX) 5949 continue; 5950 if (binpath[0] != '\0' && 5951 strlcat(binpath, "/", PATH_MAX) >= PATH_MAX) 5952 continue; 5953 if (strlcat(binpath, argv0, PATH_MAX) >= PATH_MAX) 5954 continue; 5955 fd = open(binpath, O_RDONLY | O_CLOEXEC | O_VERIFY); 5956 if (fd != -1 || errno != ENOENT) { 5957 res = binpath; 5958 break; 5959 } 5960 } 5961 free(pathenv); 5962 } else { 5963 fd = open(argv0, O_RDONLY | O_CLOEXEC | O_VERIFY); 5964 res = argv0; 5965 } 5966 5967 if (fd == -1) { 5968 _rtld_error("Cannot open %s: %s", argv0, rtld_strerror(errno)); 5969 rtld_die(); 5970 } 5971 if (res != NULL && res[0] != '/') { 5972 res1 = xmalloc(PATH_MAX); 5973 if (realpath(res, res1) != NULL) { 5974 if (res != argv0) 5975 free(__DECONST(char *, res)); 5976 res = res1; 5977 } else { 5978 free(res1); 5979 } 5980 } 5981 *binpath_res = res; 5982 return (fd); 5983 } 5984 5985 /* 5986 * Parse a set of command-line arguments. 5987 */ 5988 static int 5989 parse_args(char* argv[], int argc, bool *use_pathp, int *fdp, 5990 const char **argv0, bool *dir_ignore) 5991 { 5992 const char *arg; 5993 char machine[64]; 5994 size_t sz; 5995 int arglen, fd, i, j, mib[2]; 5996 char opt; 5997 bool seen_b, seen_f; 5998 5999 dbg("Parsing command-line arguments"); 6000 *use_pathp = false; 6001 *fdp = -1; 6002 *dir_ignore = false; 6003 seen_b = seen_f = false; 6004 6005 for (i = 1; i < argc; i++ ) { 6006 arg = argv[i]; 6007 dbg("argv[%d]: '%s'", i, arg); 6008 6009 /* 6010 * rtld arguments end with an explicit "--" or with the first 6011 * non-prefixed argument. 6012 */ 6013 if (strcmp(arg, "--") == 0) { 6014 i++; 6015 break; 6016 } 6017 if (arg[0] != '-') 6018 break; 6019 6020 /* 6021 * All other arguments are single-character options that can 6022 * be combined, so we need to search through `arg` for them. 6023 */ 6024 arglen = strlen(arg); 6025 for (j = 1; j < arglen; j++) { 6026 opt = arg[j]; 6027 if (opt == 'h') { 6028 print_usage(argv[0]); 6029 _exit(0); 6030 } else if (opt == 'b') { 6031 if (seen_f) { 6032 _rtld_error("Both -b and -f specified"); 6033 rtld_die(); 6034 } 6035 i++; 6036 *argv0 = argv[i]; 6037 seen_b = true; 6038 break; 6039 } else if (opt == 'd') { 6040 *dir_ignore = true; 6041 break; 6042 } else if (opt == 'f') { 6043 if (seen_b) { 6044 _rtld_error("Both -b and -f specified"); 6045 rtld_die(); 6046 } 6047 6048 /* 6049 * -f XX can be used to specify a 6050 * descriptor for the binary named at 6051 * the command line (i.e., the later 6052 * argument will specify the process 6053 * name but the descriptor is what 6054 * will actually be executed). 6055 * 6056 * -f must be the last option in, e.g., -abcf. 6057 */ 6058 if (j != arglen - 1) { 6059 _rtld_error("Invalid options: %s", arg); 6060 rtld_die(); 6061 } 6062 i++; 6063 fd = parse_integer(argv[i]); 6064 if (fd == -1) { 6065 _rtld_error( 6066 "Invalid file descriptor: '%s'", 6067 argv[i]); 6068 rtld_die(); 6069 } 6070 *fdp = fd; 6071 seen_f = true; 6072 break; 6073 } else if (opt == 'p') { 6074 *use_pathp = true; 6075 } else if (opt == 'u') { 6076 trust = false; 6077 } else if (opt == 'v') { 6078 machine[0] = '\0'; 6079 mib[0] = CTL_HW; 6080 mib[1] = HW_MACHINE; 6081 sz = sizeof(machine); 6082 sysctl(mib, nitems(mib), machine, &sz, NULL, 0); 6083 ld_elf_hints_path = ld_get_env_var( 6084 LD_ELF_HINTS_PATH); 6085 set_ld_elf_hints_path(); 6086 rtld_printf( 6087 "FreeBSD ld-elf.so.1 %s\n" 6088 "FreeBSD_version %d\n" 6089 "Default lib path %s\n" 6090 "Hints lib path %s\n" 6091 "Env prefix %s\n" 6092 "Default hint file %s\n" 6093 "Hint file %s\n" 6094 "libmap file %s\n", 6095 machine, 6096 __FreeBSD_version, ld_standard_library_path, 6097 gethints(false), 6098 ld_env_prefix, ld_elf_hints_default, 6099 ld_elf_hints_path, 6100 ld_path_libmap_conf); 6101 _exit(0); 6102 } else { 6103 _rtld_error("Invalid argument: '%s'", arg); 6104 print_usage(argv[0]); 6105 rtld_die(); 6106 } 6107 } 6108 } 6109 6110 if (!seen_b) 6111 *argv0 = argv[i]; 6112 return (i); 6113 } 6114 6115 /* 6116 * Parse a file descriptor number without pulling in more of libc (e.g. atoi). 6117 */ 6118 static int 6119 parse_integer(const char *str) 6120 { 6121 static const int RADIX = 10; /* XXXJA: possibly support hex? */ 6122 const char *orig; 6123 int n; 6124 char c; 6125 6126 orig = str; 6127 n = 0; 6128 for (c = *str; c != '\0'; c = *++str) { 6129 if (c < '0' || c > '9') 6130 return (-1); 6131 6132 n *= RADIX; 6133 n += c - '0'; 6134 } 6135 6136 /* Make sure we actually parsed something. */ 6137 if (str == orig) 6138 return (-1); 6139 return (n); 6140 } 6141 6142 static void 6143 print_usage(const char *argv0) 6144 { 6145 6146 rtld_printf( 6147 "Usage: %s [-h] [-b <exe>] [-d] [-f <FD>] [-p] [--] <binary> [<args>]\n" 6148 "\n" 6149 "Options:\n" 6150 " -h Display this help message\n" 6151 " -b <exe> Execute <exe> instead of <binary>, arg0 is <binary>\n" 6152 " -d Ignore lack of exec permissions for the binary\n" 6153 " -f <FD> Execute <FD> instead of searching for <binary>\n" 6154 " -p Search in PATH for named binary\n" 6155 " -u Ignore LD_ environment variables\n" 6156 " -v Display identification information\n" 6157 " -- End of RTLD options\n" 6158 " <binary> Name of process to execute\n" 6159 " <args> Arguments to the executed process\n", argv0); 6160 } 6161 6162 #define AUXFMT(at, xfmt) [at] = { .name = #at, .fmt = xfmt } 6163 static const struct auxfmt { 6164 const char *name; 6165 const char *fmt; 6166 } auxfmts[] = { 6167 AUXFMT(AT_NULL, NULL), 6168 AUXFMT(AT_IGNORE, NULL), 6169 AUXFMT(AT_EXECFD, "%ld"), 6170 AUXFMT(AT_PHDR, "%p"), 6171 AUXFMT(AT_PHENT, "%lu"), 6172 AUXFMT(AT_PHNUM, "%lu"), 6173 AUXFMT(AT_PAGESZ, "%lu"), 6174 AUXFMT(AT_BASE, "%#lx"), 6175 AUXFMT(AT_FLAGS, "%#lx"), 6176 AUXFMT(AT_ENTRY, "%p"), 6177 AUXFMT(AT_NOTELF, NULL), 6178 AUXFMT(AT_UID, "%ld"), 6179 AUXFMT(AT_EUID, "%ld"), 6180 AUXFMT(AT_GID, "%ld"), 6181 AUXFMT(AT_EGID, "%ld"), 6182 AUXFMT(AT_EXECPATH, "%s"), 6183 AUXFMT(AT_CANARY, "%p"), 6184 AUXFMT(AT_CANARYLEN, "%lu"), 6185 AUXFMT(AT_OSRELDATE, "%lu"), 6186 AUXFMT(AT_NCPUS, "%lu"), 6187 AUXFMT(AT_PAGESIZES, "%p"), 6188 AUXFMT(AT_PAGESIZESLEN, "%lu"), 6189 AUXFMT(AT_TIMEKEEP, "%p"), 6190 AUXFMT(AT_STACKPROT, "%#lx"), 6191 AUXFMT(AT_EHDRFLAGS, "%#lx"), 6192 AUXFMT(AT_HWCAP, "%#lx"), 6193 AUXFMT(AT_HWCAP2, "%#lx"), 6194 AUXFMT(AT_BSDFLAGS, "%#lx"), 6195 AUXFMT(AT_ARGC, "%lu"), 6196 AUXFMT(AT_ARGV, "%p"), 6197 AUXFMT(AT_ENVC, "%p"), 6198 AUXFMT(AT_ENVV, "%p"), 6199 AUXFMT(AT_PS_STRINGS, "%p"), 6200 AUXFMT(AT_FXRNG, "%p"), 6201 AUXFMT(AT_KPRELOAD, "%p"), 6202 AUXFMT(AT_USRSTACKBASE, "%#lx"), 6203 AUXFMT(AT_USRSTACKLIM, "%#lx"), 6204 }; 6205 6206 static bool 6207 is_ptr_fmt(const char *fmt) 6208 { 6209 char last; 6210 6211 last = fmt[strlen(fmt) - 1]; 6212 return (last == 'p' || last == 's'); 6213 } 6214 6215 static void 6216 dump_auxv(Elf_Auxinfo **aux_info) 6217 { 6218 Elf_Auxinfo *auxp; 6219 const struct auxfmt *fmt; 6220 int i; 6221 6222 for (i = 0; i < AT_COUNT; i++) { 6223 auxp = aux_info[i]; 6224 if (auxp == NULL) 6225 continue; 6226 fmt = &auxfmts[i]; 6227 if (fmt->fmt == NULL) 6228 continue; 6229 rtld_fdprintf(STDOUT_FILENO, "%s:\t", fmt->name); 6230 if (is_ptr_fmt(fmt->fmt)) { 6231 rtld_fdprintfx(STDOUT_FILENO, fmt->fmt, 6232 auxp->a_un.a_ptr); 6233 } else { 6234 rtld_fdprintfx(STDOUT_FILENO, fmt->fmt, 6235 auxp->a_un.a_val); 6236 } 6237 rtld_fdprintf(STDOUT_FILENO, "\n"); 6238 } 6239 } 6240 6241 /* 6242 * Overrides for libc_pic-provided functions. 6243 */ 6244 6245 int 6246 __getosreldate(void) 6247 { 6248 size_t len; 6249 int oid[2]; 6250 int error, osrel; 6251 6252 if (osreldate != 0) 6253 return (osreldate); 6254 6255 oid[0] = CTL_KERN; 6256 oid[1] = KERN_OSRELDATE; 6257 osrel = 0; 6258 len = sizeof(osrel); 6259 error = sysctl(oid, 2, &osrel, &len, NULL, 0); 6260 if (error == 0 && osrel > 0 && len == sizeof(osrel)) 6261 osreldate = osrel; 6262 return (osreldate); 6263 } 6264 const char * 6265 rtld_strerror(int errnum) 6266 { 6267 6268 if (errnum < 0 || errnum >= sys_nerr) 6269 return ("Unknown error"); 6270 return (sys_errlist[errnum]); 6271 } 6272 6273 char * 6274 getenv(const char *name) 6275 { 6276 return (__DECONST(char *, rtld_get_env_val(environ, name, 6277 strlen(name)))); 6278 } 6279 6280 /* malloc */ 6281 void * 6282 malloc(size_t nbytes) 6283 { 6284 6285 return (__crt_malloc(nbytes)); 6286 } 6287 6288 void * 6289 calloc(size_t num, size_t size) 6290 { 6291 6292 return (__crt_calloc(num, size)); 6293 } 6294 6295 void 6296 free(void *cp) 6297 { 6298 6299 __crt_free(cp); 6300 } 6301 6302 void * 6303 realloc(void *cp, size_t nbytes) 6304 { 6305 6306 return (__crt_realloc(cp, nbytes)); 6307 } 6308 6309 extern int _rtld_version__FreeBSD_version __exported; 6310 int _rtld_version__FreeBSD_version = __FreeBSD_version; 6311 6312 extern char _rtld_version_laddr_offset __exported; 6313 char _rtld_version_laddr_offset; 6314 6315 extern char _rtld_version_dlpi_tls_data __exported; 6316 char _rtld_version_dlpi_tls_data; 6317