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 *); 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); 266 267 268 int npagesizes; 269 static int osreldate; 270 size_t *pagesizes; 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 /* 481 * Main entry point for dynamic linking. The first argument is the 482 * stack pointer. The stack is expected to be laid out as described 483 * in the SVR4 ABI specification, Intel 386 Processor Supplement. 484 * Specifically, the stack pointer points to a word containing 485 * ARGC. Following that in the stack is a null-terminated sequence 486 * of pointers to argument strings. Then comes a null-terminated 487 * sequence of pointers to environment strings. Finally, there is a 488 * sequence of "auxiliary vector" entries. 489 * 490 * The second argument points to a place to store the dynamic linker's 491 * exit procedure pointer and the third to a place to store the main 492 * program's object. 493 * 494 * The return value is the main program's entry point. 495 */ 496 func_ptr_type 497 _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp) 498 { 499 Elf_Auxinfo *aux, *auxp, *auxpf, *aux_info[AT_COUNT]; 500 Objlist_Entry *entry; 501 Obj_Entry *last_interposer, *obj, *preload_tail; 502 const Elf_Phdr *phdr; 503 Objlist initlist; 504 RtldLockState lockstate; 505 struct stat st; 506 Elf_Addr *argcp; 507 char **argv, **env, **envp, *kexecpath; 508 const char *argv0, *binpath, *library_path_rpath; 509 struct ld_env_var_desc *lvd; 510 caddr_t imgentry; 511 char buf[MAXPATHLEN]; 512 int argc, fd, i, mib[4], old_osrel, osrel, phnum, rtld_argc; 513 size_t sz; 514 #ifdef __powerpc__ 515 int old_auxv_format = 1; 516 #endif 517 bool dir_enable, dir_ignore, direct_exec, explicit_fd, search_in_path; 518 519 /* 520 * On entry, the dynamic linker itself has not been relocated yet. 521 * Be very careful not to reference any global data until after 522 * init_rtld has returned. It is OK to reference file-scope statics 523 * and string constants, and to call static and global functions. 524 */ 525 526 /* Find the auxiliary vector on the stack. */ 527 argcp = sp; 528 argc = *sp++; 529 argv = (char **) sp; 530 sp += argc + 1; /* Skip over arguments and NULL terminator */ 531 env = (char **) sp; 532 while (*sp++ != 0) /* Skip over environment, and NULL terminator */ 533 ; 534 aux = (Elf_Auxinfo *) sp; 535 536 /* Digest the auxiliary vector. */ 537 for (i = 0; i < AT_COUNT; i++) 538 aux_info[i] = NULL; 539 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) { 540 if (auxp->a_type < AT_COUNT) 541 aux_info[auxp->a_type] = auxp; 542 #ifdef __powerpc__ 543 if (auxp->a_type == 23) /* AT_STACKPROT */ 544 old_auxv_format = 0; 545 #endif 546 } 547 548 #ifdef __powerpc__ 549 if (old_auxv_format) { 550 /* Remap from old-style auxv numbers. */ 551 aux_info[23] = aux_info[21]; /* AT_STACKPROT */ 552 aux_info[21] = aux_info[19]; /* AT_PAGESIZESLEN */ 553 aux_info[19] = aux_info[17]; /* AT_NCPUS */ 554 aux_info[17] = aux_info[15]; /* AT_CANARYLEN */ 555 aux_info[15] = aux_info[13]; /* AT_EXECPATH */ 556 aux_info[13] = NULL; /* AT_GID */ 557 558 aux_info[20] = aux_info[18]; /* AT_PAGESIZES */ 559 aux_info[18] = aux_info[16]; /* AT_OSRELDATE */ 560 aux_info[16] = aux_info[14]; /* AT_CANARY */ 561 aux_info[14] = NULL; /* AT_EGID */ 562 } 563 #endif 564 565 /* Initialize and relocate ourselves. */ 566 assert(aux_info[AT_BASE] != NULL); 567 init_rtld((caddr_t) aux_info[AT_BASE]->a_un.a_ptr, aux_info); 568 569 dlerror_dflt_init(); 570 571 __progname = obj_rtld.path; 572 argv0 = argv[0] != NULL ? argv[0] : "(null)"; 573 environ = env; 574 main_argc = argc; 575 main_argv = argv; 576 577 if (aux_info[AT_BSDFLAGS] != NULL && 578 (aux_info[AT_BSDFLAGS]->a_un.a_val & ELF_BSDF_SIGFASTBLK) != 0) 579 ld_fast_sigblock = true; 580 581 trust = !issetugid(); 582 direct_exec = false; 583 584 md_abi_variant_hook(aux_info); 585 rtld_init_env_vars(env); 586 587 fd = -1; 588 if (aux_info[AT_EXECFD] != NULL) { 589 fd = aux_info[AT_EXECFD]->a_un.a_val; 590 } else { 591 assert(aux_info[AT_PHDR] != NULL); 592 phdr = (const Elf_Phdr *)aux_info[AT_PHDR]->a_un.a_ptr; 593 if (phdr == obj_rtld.phdr) { 594 if (!trust) { 595 _rtld_error("Tainted process refusing to run binary %s", 596 argv0); 597 rtld_die(); 598 } 599 direct_exec = true; 600 601 dbg("opening main program in direct exec mode"); 602 if (argc >= 2) { 603 rtld_argc = parse_args(argv, argc, &search_in_path, &fd, 604 &argv0, &dir_ignore); 605 explicit_fd = (fd != -1); 606 binpath = NULL; 607 if (!explicit_fd) 608 fd = open_binary_fd(argv0, search_in_path, &binpath); 609 if (fstat(fd, &st) == -1) { 610 _rtld_error("Failed to fstat FD %d (%s): %s", fd, 611 explicit_fd ? "user-provided descriptor" : argv0, 612 rtld_strerror(errno)); 613 rtld_die(); 614 } 615 616 /* 617 * Rough emulation of the permission checks done by 618 * execve(2), only Unix DACs are checked, ACLs are 619 * ignored. Preserve the semantic of disabling owner 620 * to execute if owner x bit is cleared, even if 621 * others x bit is enabled. 622 * mmap(2) does not allow to mmap with PROT_EXEC if 623 * binary' file comes from noexec mount. We cannot 624 * set a text reference on the binary. 625 */ 626 dir_enable = false; 627 if (st.st_uid == geteuid()) { 628 if ((st.st_mode & S_IXUSR) != 0) 629 dir_enable = true; 630 } else if (st.st_gid == getegid()) { 631 if ((st.st_mode & S_IXGRP) != 0) 632 dir_enable = true; 633 } else if ((st.st_mode & S_IXOTH) != 0) { 634 dir_enable = true; 635 } 636 if (!dir_enable && !dir_ignore) { 637 _rtld_error("No execute permission for binary %s", 638 argv0); 639 rtld_die(); 640 } 641 642 /* 643 * For direct exec mode, argv[0] is the interpreter 644 * name, we must remove it and shift arguments left 645 * before invoking binary main. Since stack layout 646 * places environment pointers and aux vectors right 647 * after the terminating NULL, we must shift 648 * environment and aux as well. 649 */ 650 main_argc = argc - rtld_argc; 651 for (i = 0; i <= main_argc; i++) 652 argv[i] = argv[i + rtld_argc]; 653 *argcp -= rtld_argc; 654 environ = env = envp = argv + main_argc + 1; 655 dbg("move env from %p to %p", envp + rtld_argc, envp); 656 do { 657 *envp = *(envp + rtld_argc); 658 } while (*envp++ != NULL); 659 aux = auxp = (Elf_Auxinfo *)envp; 660 auxpf = (Elf_Auxinfo *)(envp + rtld_argc); 661 dbg("move aux from %p to %p", auxpf, aux); 662 /* XXXKIB insert place for AT_EXECPATH if not present */ 663 for (;; auxp++, auxpf++) { 664 *auxp = *auxpf; 665 if (auxp->a_type == AT_NULL) 666 break; 667 } 668 /* Since the auxiliary vector has moved, redigest it. */ 669 for (i = 0; i < AT_COUNT; i++) 670 aux_info[i] = NULL; 671 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) { 672 if (auxp->a_type < AT_COUNT) 673 aux_info[auxp->a_type] = auxp; 674 } 675 676 /* Point AT_EXECPATH auxv and aux_info to the binary path. */ 677 if (binpath == NULL) { 678 aux_info[AT_EXECPATH] = NULL; 679 } else { 680 if (aux_info[AT_EXECPATH] == NULL) { 681 aux_info[AT_EXECPATH] = xmalloc(sizeof(Elf_Auxinfo)); 682 aux_info[AT_EXECPATH]->a_type = AT_EXECPATH; 683 } 684 aux_info[AT_EXECPATH]->a_un.a_ptr = __DECONST(void *, 685 binpath); 686 } 687 } else { 688 _rtld_error("No binary"); 689 rtld_die(); 690 } 691 } 692 } 693 694 ld_bind_now = ld_get_env_var(LD_BIND_NOW); 695 696 /* 697 * If the process is tainted, then we un-set the dangerous environment 698 * variables. The process will be marked as tainted until setuid(2) 699 * is called. If any child process calls setuid(2) we do not want any 700 * future processes to honor the potentially un-safe variables. 701 */ 702 if (!trust) { 703 for (i = 0; i < (int)nitems(ld_env_vars); i++) { 704 lvd = &ld_env_vars[i]; 705 if (lvd->unsecure) 706 lvd->val = NULL; 707 } 708 } 709 710 ld_debug = ld_get_env_var(LD_DEBUG); 711 if (ld_bind_now == NULL) 712 ld_bind_not = ld_get_env_var(LD_BIND_NOT) != NULL; 713 ld_dynamic_weak = ld_get_env_var(LD_DYNAMIC_WEAK) == NULL; 714 libmap_disable = ld_get_env_var(LD_LIBMAP_DISABLE) != NULL; 715 libmap_override = ld_get_env_var(LD_LIBMAP); 716 ld_library_path = ld_get_env_var(LD_LIBRARY_PATH); 717 ld_library_dirs = ld_get_env_var(LD_LIBRARY_PATH_FDS); 718 ld_preload = ld_get_env_var(LD_PRELOAD); 719 ld_preload_fds = ld_get_env_var(LD_PRELOAD_FDS); 720 ld_elf_hints_path = ld_get_env_var(LD_ELF_HINTS_PATH); 721 ld_loadfltr = ld_get_env_var(LD_LOADFLTR) != NULL; 722 library_path_rpath = ld_get_env_var(LD_LIBRARY_PATH_RPATH); 723 if (library_path_rpath != NULL) { 724 if (library_path_rpath[0] == 'y' || 725 library_path_rpath[0] == 'Y' || 726 library_path_rpath[0] == '1') 727 ld_library_path_rpath = true; 728 else 729 ld_library_path_rpath = false; 730 } 731 dangerous_ld_env = libmap_disable || libmap_override != NULL || 732 ld_library_path != NULL || ld_preload != NULL || 733 ld_elf_hints_path != NULL || ld_loadfltr || !ld_dynamic_weak; 734 ld_tracing = ld_get_env_var(LD_TRACE_LOADED_OBJECTS); 735 ld_utrace = ld_get_env_var(LD_UTRACE); 736 737 set_ld_elf_hints_path(); 738 if (ld_debug != NULL && *ld_debug != '\0') 739 debug = 1; 740 dbg("%s is initialized, base address = %p", __progname, 741 (caddr_t) aux_info[AT_BASE]->a_un.a_ptr); 742 dbg("RTLD dynamic = %p", obj_rtld.dynamic); 743 dbg("RTLD pltgot = %p", obj_rtld.pltgot); 744 745 dbg("initializing thread locks"); 746 lockdflt_init(); 747 748 /* 749 * Load the main program, or process its program header if it is 750 * already loaded. 751 */ 752 if (fd != -1) { /* Load the main program. */ 753 dbg("loading main program"); 754 obj_main = map_object(fd, argv0, NULL); 755 close(fd); 756 if (obj_main == NULL) 757 rtld_die(); 758 max_stack_flags = obj_main->stack_flags; 759 } else { /* Main program already loaded. */ 760 dbg("processing main program's program header"); 761 assert(aux_info[AT_PHDR] != NULL); 762 phdr = (const Elf_Phdr *) aux_info[AT_PHDR]->a_un.a_ptr; 763 assert(aux_info[AT_PHNUM] != NULL); 764 phnum = aux_info[AT_PHNUM]->a_un.a_val; 765 assert(aux_info[AT_PHENT] != NULL); 766 assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr)); 767 assert(aux_info[AT_ENTRY] != NULL); 768 imgentry = (caddr_t) aux_info[AT_ENTRY]->a_un.a_ptr; 769 if ((obj_main = digest_phdr(phdr, phnum, imgentry, argv0)) == NULL) 770 rtld_die(); 771 } 772 773 if (aux_info[AT_EXECPATH] != NULL && fd == -1) { 774 kexecpath = aux_info[AT_EXECPATH]->a_un.a_ptr; 775 dbg("AT_EXECPATH %p %s", kexecpath, kexecpath); 776 if (kexecpath[0] == '/') 777 obj_main->path = kexecpath; 778 else if (getcwd(buf, sizeof(buf)) == NULL || 779 strlcat(buf, "/", sizeof(buf)) >= sizeof(buf) || 780 strlcat(buf, kexecpath, sizeof(buf)) >= sizeof(buf)) 781 obj_main->path = xstrdup(argv0); 782 else 783 obj_main->path = xstrdup(buf); 784 } else { 785 dbg("No AT_EXECPATH or direct exec"); 786 obj_main->path = xstrdup(argv0); 787 } 788 dbg("obj_main path %s", obj_main->path); 789 obj_main->mainprog = true; 790 791 if (aux_info[AT_STACKPROT] != NULL && 792 aux_info[AT_STACKPROT]->a_un.a_val != 0) 793 stack_prot = aux_info[AT_STACKPROT]->a_un.a_val; 794 795 #ifndef COMPAT_32BIT 796 /* 797 * Get the actual dynamic linker pathname from the executable if 798 * possible. (It should always be possible.) That ensures that 799 * gdb will find the right dynamic linker even if a non-standard 800 * one is being used. 801 */ 802 if (obj_main->interp != NULL && 803 strcmp(obj_main->interp, obj_rtld.path) != 0) { 804 free(obj_rtld.path); 805 obj_rtld.path = xstrdup(obj_main->interp); 806 __progname = obj_rtld.path; 807 } 808 #endif 809 810 if (!digest_dynamic(obj_main, 0)) 811 rtld_die(); 812 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", 813 obj_main->path, obj_main->valid_hash_sysv, obj_main->valid_hash_gnu, 814 obj_main->dynsymcount); 815 816 linkmap_add(obj_main); 817 linkmap_add(&obj_rtld); 818 819 /* Link the main program into the list of objects. */ 820 TAILQ_INSERT_HEAD(&obj_list, obj_main, next); 821 obj_count++; 822 obj_loads++; 823 824 /* Initialize a fake symbol for resolving undefined weak references. */ 825 sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE); 826 sym_zero.st_shndx = SHN_UNDEF; 827 sym_zero.st_value = -(uintptr_t)obj_main->relocbase; 828 829 if (!libmap_disable) 830 libmap_disable = (bool)lm_init(libmap_override); 831 832 if (aux_info[AT_KPRELOAD] != NULL && 833 aux_info[AT_KPRELOAD]->a_un.a_ptr != NULL) { 834 dbg("loading kernel vdso"); 835 if (load_kpreload(aux_info[AT_KPRELOAD]->a_un.a_ptr) == -1) 836 rtld_die(); 837 } 838 839 dbg("loading LD_PRELOAD_FDS libraries"); 840 if (load_preload_objects(ld_preload_fds, true) == -1) 841 rtld_die(); 842 843 dbg("loading LD_PRELOAD libraries"); 844 if (load_preload_objects(ld_preload, false) == -1) 845 rtld_die(); 846 preload_tail = globallist_curr(TAILQ_LAST(&obj_list, obj_entry_q)); 847 848 dbg("loading needed objects"); 849 if (load_needed_objects(obj_main, ld_tracing != NULL ? RTLD_LO_TRACE : 850 0) == -1) 851 rtld_die(); 852 853 /* Make a list of all objects loaded at startup. */ 854 last_interposer = obj_main; 855 TAILQ_FOREACH(obj, &obj_list, next) { 856 if (obj->marker) 857 continue; 858 if (obj->z_interpose && obj != obj_main) { 859 objlist_put_after(&list_main, last_interposer, obj); 860 last_interposer = obj; 861 } else { 862 objlist_push_tail(&list_main, obj); 863 } 864 obj->refcount++; 865 } 866 867 dbg("checking for required versions"); 868 if (rtld_verify_versions(&list_main) == -1 && !ld_tracing) 869 rtld_die(); 870 871 if (ld_get_env_var(LD_SHOW_AUXV) != NULL) 872 dump_auxv(aux_info); 873 874 if (ld_tracing) { /* We're done */ 875 trace_loaded_objects(obj_main); 876 exit(0); 877 } 878 879 if (ld_get_env_var(LD_DUMP_REL_PRE) != NULL) { 880 dump_relocations(obj_main); 881 exit (0); 882 } 883 884 /* 885 * Processing tls relocations requires having the tls offsets 886 * initialized. Prepare offsets before starting initial 887 * relocation processing. 888 */ 889 dbg("initializing initial thread local storage offsets"); 890 STAILQ_FOREACH(entry, &list_main, link) { 891 /* 892 * Allocate all the initial objects out of the static TLS 893 * block even if they didn't ask for it. 894 */ 895 allocate_tls_offset(entry->obj); 896 } 897 898 if (relocate_objects(obj_main, 899 ld_bind_now != NULL && *ld_bind_now != '\0', 900 &obj_rtld, SYMLOOK_EARLY, NULL) == -1) 901 rtld_die(); 902 903 dbg("doing copy relocations"); 904 if (do_copy_relocations(obj_main) == -1) 905 rtld_die(); 906 907 if (ld_get_env_var(LD_DUMP_REL_POST) != NULL) { 908 dump_relocations(obj_main); 909 exit (0); 910 } 911 912 ifunc_init(aux); 913 914 /* 915 * Setup TLS for main thread. This must be done after the 916 * relocations are processed, since tls initialization section 917 * might be the subject for relocations. 918 */ 919 dbg("initializing initial thread local storage"); 920 allocate_initial_tls(globallist_curr(TAILQ_FIRST(&obj_list))); 921 922 dbg("initializing key program variables"); 923 set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : ""); 924 set_program_var("environ", env); 925 set_program_var("__elf_aux_vector", aux); 926 927 /* Make a list of init functions to call. */ 928 objlist_init(&initlist); 929 initlist_add_objects(globallist_curr(TAILQ_FIRST(&obj_list)), 930 preload_tail, &initlist); 931 932 r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */ 933 934 map_stacks_exec(NULL); 935 936 if (!obj_main->crt_no_init) { 937 /* 938 * Make sure we don't call the main program's init and fini 939 * functions for binaries linked with old crt1 which calls 940 * _init itself. 941 */ 942 obj_main->init = obj_main->fini = (Elf_Addr)NULL; 943 obj_main->preinit_array = obj_main->init_array = 944 obj_main->fini_array = (Elf_Addr)NULL; 945 } 946 947 if (direct_exec) { 948 /* Set osrel for direct-execed binary */ 949 mib[0] = CTL_KERN; 950 mib[1] = KERN_PROC; 951 mib[2] = KERN_PROC_OSREL; 952 mib[3] = getpid(); 953 osrel = obj_main->osrel; 954 sz = sizeof(old_osrel); 955 dbg("setting osrel to %d", osrel); 956 (void)sysctl(mib, 4, &old_osrel, &sz, &osrel, sizeof(osrel)); 957 } 958 959 wlock_acquire(rtld_bind_lock, &lockstate); 960 961 dbg("resolving ifuncs"); 962 if (initlist_objects_ifunc(&initlist, ld_bind_now != NULL && 963 *ld_bind_now != '\0', SYMLOOK_EARLY, &lockstate) == -1) 964 rtld_die(); 965 966 rtld_exit_ptr = rtld_exit; 967 if (obj_main->crt_no_init) 968 preinit_main(); 969 objlist_call_init(&initlist, &lockstate); 970 _r_debug_postinit(&obj_main->linkmap); 971 objlist_clear(&initlist); 972 dbg("loading filtees"); 973 TAILQ_FOREACH(obj, &obj_list, next) { 974 if (obj->marker) 975 continue; 976 if (ld_loadfltr || obj->z_loadfltr) 977 load_filtees(obj, 0, &lockstate); 978 } 979 980 dbg("enforcing main obj relro"); 981 if (obj_enforce_relro(obj_main) == -1) 982 rtld_die(); 983 984 lock_release(rtld_bind_lock, &lockstate); 985 986 dbg("transferring control to program entry point = %p", obj_main->entry); 987 988 /* Return the exit procedure and the program entry point. */ 989 *exit_proc = rtld_exit_ptr; 990 *objp = obj_main; 991 return ((func_ptr_type)obj_main->entry); 992 } 993 994 void * 995 rtld_resolve_ifunc(const Obj_Entry *obj, const Elf_Sym *def) 996 { 997 void *ptr; 998 Elf_Addr target; 999 1000 ptr = (void *)make_function_pointer(def, obj); 1001 target = call_ifunc_resolver(ptr); 1002 return ((void *)target); 1003 } 1004 1005 Elf_Addr 1006 _rtld_bind(Obj_Entry *obj, Elf_Size reloff) 1007 { 1008 const Elf_Rel *rel; 1009 const Elf_Sym *def; 1010 const Obj_Entry *defobj; 1011 Elf_Addr *where; 1012 Elf_Addr target; 1013 RtldLockState lockstate; 1014 1015 rlock_acquire(rtld_bind_lock, &lockstate); 1016 if (sigsetjmp(lockstate.env, 0) != 0) 1017 lock_upgrade(rtld_bind_lock, &lockstate); 1018 if (obj->pltrel) 1019 rel = (const Elf_Rel *)((const char *)obj->pltrel + reloff); 1020 else 1021 rel = (const Elf_Rel *)((const char *)obj->pltrela + reloff); 1022 1023 where = (Elf_Addr *)(obj->relocbase + rel->r_offset); 1024 def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, SYMLOOK_IN_PLT, 1025 NULL, &lockstate); 1026 if (def == NULL) 1027 rtld_die(); 1028 if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 1029 target = (Elf_Addr)rtld_resolve_ifunc(defobj, def); 1030 else 1031 target = (Elf_Addr)(defobj->relocbase + def->st_value); 1032 1033 dbg("\"%s\" in \"%s\" ==> %p in \"%s\"", 1034 defobj->strtab + def->st_name, 1035 obj->path == NULL ? NULL : basename(obj->path), 1036 (void *)target, 1037 defobj->path == NULL ? NULL : basename(defobj->path)); 1038 1039 /* 1040 * Write the new contents for the jmpslot. Note that depending on 1041 * architecture, the value which we need to return back to the 1042 * lazy binding trampoline may or may not be the target 1043 * address. The value returned from reloc_jmpslot() is the value 1044 * that the trampoline needs. 1045 */ 1046 target = reloc_jmpslot(where, target, defobj, obj, rel); 1047 lock_release(rtld_bind_lock, &lockstate); 1048 return (target); 1049 } 1050 1051 /* 1052 * Error reporting function. Use it like printf. If formats the message 1053 * into a buffer, and sets things up so that the next call to dlerror() 1054 * will return the message. 1055 */ 1056 void 1057 _rtld_error(const char *fmt, ...) 1058 { 1059 va_list ap; 1060 1061 va_start(ap, fmt); 1062 rtld_vsnprintf(lockinfo.dlerror_loc(), lockinfo.dlerror_loc_sz, 1063 fmt, ap); 1064 va_end(ap); 1065 *lockinfo.dlerror_seen() = 0; 1066 LD_UTRACE(UTRACE_RTLD_ERROR, NULL, NULL, 0, 0, lockinfo.dlerror_loc()); 1067 } 1068 1069 /* 1070 * Return a dynamically-allocated copy of the current error message, if any. 1071 */ 1072 static struct dlerror_save * 1073 errmsg_save(void) 1074 { 1075 struct dlerror_save *res; 1076 1077 res = xmalloc(sizeof(*res)); 1078 res->seen = *lockinfo.dlerror_seen(); 1079 if (res->seen == 0) 1080 res->msg = xstrdup(lockinfo.dlerror_loc()); 1081 return (res); 1082 } 1083 1084 /* 1085 * Restore the current error message from a copy which was previously saved 1086 * by errmsg_save(). The copy is freed. 1087 */ 1088 static void 1089 errmsg_restore(struct dlerror_save *saved_msg) 1090 { 1091 if (saved_msg == NULL || saved_msg->seen == 1) { 1092 *lockinfo.dlerror_seen() = 1; 1093 } else { 1094 *lockinfo.dlerror_seen() = 0; 1095 strlcpy(lockinfo.dlerror_loc(), saved_msg->msg, 1096 lockinfo.dlerror_loc_sz); 1097 free(saved_msg->msg); 1098 } 1099 free(saved_msg); 1100 } 1101 1102 static const char * 1103 basename(const char *name) 1104 { 1105 const char *p; 1106 1107 p = strrchr(name, '/'); 1108 return (p != NULL ? p + 1 : name); 1109 } 1110 1111 static struct utsname uts; 1112 1113 static char * 1114 origin_subst_one(Obj_Entry *obj, char *real, const char *kw, 1115 const char *subst, bool may_free) 1116 { 1117 char *p, *p1, *res, *resp; 1118 int subst_len, kw_len, subst_count, old_len, new_len; 1119 1120 kw_len = strlen(kw); 1121 1122 /* 1123 * First, count the number of the keyword occurrences, to 1124 * preallocate the final string. 1125 */ 1126 for (p = real, subst_count = 0;; p = p1 + kw_len, subst_count++) { 1127 p1 = strstr(p, kw); 1128 if (p1 == NULL) 1129 break; 1130 } 1131 1132 /* 1133 * If the keyword is not found, just return. 1134 * 1135 * Return non-substituted string if resolution failed. We 1136 * cannot do anything more reasonable, the failure mode of the 1137 * caller is unresolved library anyway. 1138 */ 1139 if (subst_count == 0 || (obj != NULL && !obj_resolve_origin(obj))) 1140 return (may_free ? real : xstrdup(real)); 1141 if (obj != NULL) 1142 subst = obj->origin_path; 1143 1144 /* 1145 * There is indeed something to substitute. Calculate the 1146 * length of the resulting string, and allocate it. 1147 */ 1148 subst_len = strlen(subst); 1149 old_len = strlen(real); 1150 new_len = old_len + (subst_len - kw_len) * subst_count; 1151 res = xmalloc(new_len + 1); 1152 1153 /* 1154 * Now, execute the substitution loop. 1155 */ 1156 for (p = real, resp = res, *resp = '\0';;) { 1157 p1 = strstr(p, kw); 1158 if (p1 != NULL) { 1159 /* Copy the prefix before keyword. */ 1160 memcpy(resp, p, p1 - p); 1161 resp += p1 - p; 1162 /* Keyword replacement. */ 1163 memcpy(resp, subst, subst_len); 1164 resp += subst_len; 1165 *resp = '\0'; 1166 p = p1 + kw_len; 1167 } else 1168 break; 1169 } 1170 1171 /* Copy to the end of string and finish. */ 1172 strcat(resp, p); 1173 if (may_free) 1174 free(real); 1175 return (res); 1176 } 1177 1178 static char * 1179 origin_subst(Obj_Entry *obj, const char *real) 1180 { 1181 char *res1, *res2, *res3, *res4; 1182 1183 if (obj == NULL || !trust) 1184 return (xstrdup(real)); 1185 if (uts.sysname[0] == '\0') { 1186 if (uname(&uts) != 0) { 1187 _rtld_error("utsname failed: %d", errno); 1188 return (NULL); 1189 } 1190 } 1191 /* __DECONST is safe here since without may_free real is unchanged */ 1192 res1 = origin_subst_one(obj, __DECONST(char *, real), "$ORIGIN", NULL, 1193 false); 1194 res2 = origin_subst_one(NULL, res1, "$OSNAME", uts.sysname, true); 1195 res3 = origin_subst_one(NULL, res2, "$OSREL", uts.release, true); 1196 res4 = origin_subst_one(NULL, res3, "$PLATFORM", uts.machine, true); 1197 return (res4); 1198 } 1199 1200 void 1201 rtld_die(void) 1202 { 1203 const char *msg = dlerror(); 1204 1205 if (msg == NULL) 1206 msg = "Fatal error"; 1207 rtld_fdputstr(STDERR_FILENO, _BASENAME_RTLD ": "); 1208 rtld_fdputstr(STDERR_FILENO, msg); 1209 rtld_fdputchar(STDERR_FILENO, '\n'); 1210 _exit(1); 1211 } 1212 1213 /* 1214 * Process a shared object's DYNAMIC section, and save the important 1215 * information in its Obj_Entry structure. 1216 */ 1217 static void 1218 digest_dynamic1(Obj_Entry *obj, int early, const Elf_Dyn **dyn_rpath, 1219 const Elf_Dyn **dyn_soname, const Elf_Dyn **dyn_runpath) 1220 { 1221 const Elf_Dyn *dynp; 1222 Needed_Entry **needed_tail = &obj->needed; 1223 Needed_Entry **needed_filtees_tail = &obj->needed_filtees; 1224 Needed_Entry **needed_aux_filtees_tail = &obj->needed_aux_filtees; 1225 const Elf_Hashelt *hashtab; 1226 const Elf32_Word *hashval; 1227 Elf32_Word bkt, nmaskwords; 1228 int bloom_size32; 1229 int plttype = DT_REL; 1230 1231 *dyn_rpath = NULL; 1232 *dyn_soname = NULL; 1233 *dyn_runpath = NULL; 1234 1235 obj->bind_now = false; 1236 dynp = obj->dynamic; 1237 if (dynp == NULL) 1238 return; 1239 for (; dynp->d_tag != DT_NULL; dynp++) { 1240 switch (dynp->d_tag) { 1241 1242 case DT_REL: 1243 obj->rel = (const Elf_Rel *)(obj->relocbase + dynp->d_un.d_ptr); 1244 break; 1245 1246 case DT_RELSZ: 1247 obj->relsize = dynp->d_un.d_val; 1248 break; 1249 1250 case DT_RELENT: 1251 assert(dynp->d_un.d_val == sizeof(Elf_Rel)); 1252 break; 1253 1254 case DT_JMPREL: 1255 obj->pltrel = (const Elf_Rel *) 1256 (obj->relocbase + dynp->d_un.d_ptr); 1257 break; 1258 1259 case DT_PLTRELSZ: 1260 obj->pltrelsize = dynp->d_un.d_val; 1261 break; 1262 1263 case DT_RELA: 1264 obj->rela = (const Elf_Rela *)(obj->relocbase + dynp->d_un.d_ptr); 1265 break; 1266 1267 case DT_RELASZ: 1268 obj->relasize = dynp->d_un.d_val; 1269 break; 1270 1271 case DT_RELAENT: 1272 assert(dynp->d_un.d_val == sizeof(Elf_Rela)); 1273 break; 1274 1275 case DT_RELR: 1276 obj->relr = (const Elf_Relr *)(obj->relocbase + dynp->d_un.d_ptr); 1277 break; 1278 1279 case DT_RELRSZ: 1280 obj->relrsize = dynp->d_un.d_val; 1281 break; 1282 1283 case DT_RELRENT: 1284 assert(dynp->d_un.d_val == sizeof(Elf_Relr)); 1285 break; 1286 1287 case DT_PLTREL: 1288 plttype = dynp->d_un.d_val; 1289 assert(dynp->d_un.d_val == DT_REL || plttype == DT_RELA); 1290 break; 1291 1292 case DT_SYMTAB: 1293 obj->symtab = (const Elf_Sym *) 1294 (obj->relocbase + dynp->d_un.d_ptr); 1295 break; 1296 1297 case DT_SYMENT: 1298 assert(dynp->d_un.d_val == sizeof(Elf_Sym)); 1299 break; 1300 1301 case DT_STRTAB: 1302 obj->strtab = (const char *)(obj->relocbase + dynp->d_un.d_ptr); 1303 break; 1304 1305 case DT_STRSZ: 1306 obj->strsize = dynp->d_un.d_val; 1307 break; 1308 1309 case DT_VERNEED: 1310 obj->verneed = (const Elf_Verneed *)(obj->relocbase + 1311 dynp->d_un.d_val); 1312 break; 1313 1314 case DT_VERNEEDNUM: 1315 obj->verneednum = dynp->d_un.d_val; 1316 break; 1317 1318 case DT_VERDEF: 1319 obj->verdef = (const Elf_Verdef *)(obj->relocbase + 1320 dynp->d_un.d_val); 1321 break; 1322 1323 case DT_VERDEFNUM: 1324 obj->verdefnum = dynp->d_un.d_val; 1325 break; 1326 1327 case DT_VERSYM: 1328 obj->versyms = (const Elf_Versym *)(obj->relocbase + 1329 dynp->d_un.d_val); 1330 break; 1331 1332 case DT_HASH: 1333 { 1334 hashtab = (const Elf_Hashelt *)(obj->relocbase + 1335 dynp->d_un.d_ptr); 1336 obj->nbuckets = hashtab[0]; 1337 obj->nchains = hashtab[1]; 1338 obj->buckets = hashtab + 2; 1339 obj->chains = obj->buckets + obj->nbuckets; 1340 obj->valid_hash_sysv = obj->nbuckets > 0 && obj->nchains > 0 && 1341 obj->buckets != NULL; 1342 } 1343 break; 1344 1345 case DT_GNU_HASH: 1346 { 1347 hashtab = (const Elf_Hashelt *)(obj->relocbase + 1348 dynp->d_un.d_ptr); 1349 obj->nbuckets_gnu = hashtab[0]; 1350 obj->symndx_gnu = hashtab[1]; 1351 nmaskwords = hashtab[2]; 1352 bloom_size32 = (__ELF_WORD_SIZE / 32) * nmaskwords; 1353 obj->maskwords_bm_gnu = nmaskwords - 1; 1354 obj->shift2_gnu = hashtab[3]; 1355 obj->bloom_gnu = (const Elf_Addr *)(hashtab + 4); 1356 obj->buckets_gnu = hashtab + 4 + bloom_size32; 1357 obj->chain_zero_gnu = obj->buckets_gnu + obj->nbuckets_gnu - 1358 obj->symndx_gnu; 1359 /* Number of bitmask words is required to be power of 2 */ 1360 obj->valid_hash_gnu = powerof2(nmaskwords) && 1361 obj->nbuckets_gnu > 0 && obj->buckets_gnu != NULL; 1362 } 1363 break; 1364 1365 case DT_NEEDED: 1366 if (!obj->rtld) { 1367 Needed_Entry *nep = NEW(Needed_Entry); 1368 nep->name = dynp->d_un.d_val; 1369 nep->obj = NULL; 1370 nep->next = NULL; 1371 1372 *needed_tail = nep; 1373 needed_tail = &nep->next; 1374 } 1375 break; 1376 1377 case DT_FILTER: 1378 if (!obj->rtld) { 1379 Needed_Entry *nep = NEW(Needed_Entry); 1380 nep->name = dynp->d_un.d_val; 1381 nep->obj = NULL; 1382 nep->next = NULL; 1383 1384 *needed_filtees_tail = nep; 1385 needed_filtees_tail = &nep->next; 1386 1387 if (obj->linkmap.l_refname == NULL) 1388 obj->linkmap.l_refname = (char *)dynp->d_un.d_val; 1389 } 1390 break; 1391 1392 case DT_AUXILIARY: 1393 if (!obj->rtld) { 1394 Needed_Entry *nep = NEW(Needed_Entry); 1395 nep->name = dynp->d_un.d_val; 1396 nep->obj = NULL; 1397 nep->next = NULL; 1398 1399 *needed_aux_filtees_tail = nep; 1400 needed_aux_filtees_tail = &nep->next; 1401 } 1402 break; 1403 1404 case DT_PLTGOT: 1405 obj->pltgot = (Elf_Addr *)(obj->relocbase + dynp->d_un.d_ptr); 1406 break; 1407 1408 case DT_TEXTREL: 1409 obj->textrel = true; 1410 break; 1411 1412 case DT_SYMBOLIC: 1413 obj->symbolic = true; 1414 break; 1415 1416 case DT_RPATH: 1417 /* 1418 * We have to wait until later to process this, because we 1419 * might not have gotten the address of the string table yet. 1420 */ 1421 *dyn_rpath = dynp; 1422 break; 1423 1424 case DT_SONAME: 1425 *dyn_soname = dynp; 1426 break; 1427 1428 case DT_RUNPATH: 1429 *dyn_runpath = dynp; 1430 break; 1431 1432 case DT_INIT: 1433 obj->init = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1434 break; 1435 1436 case DT_PREINIT_ARRAY: 1437 obj->preinit_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1438 break; 1439 1440 case DT_PREINIT_ARRAYSZ: 1441 obj->preinit_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1442 break; 1443 1444 case DT_INIT_ARRAY: 1445 obj->init_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1446 break; 1447 1448 case DT_INIT_ARRAYSZ: 1449 obj->init_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1450 break; 1451 1452 case DT_FINI: 1453 obj->fini = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1454 break; 1455 1456 case DT_FINI_ARRAY: 1457 obj->fini_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1458 break; 1459 1460 case DT_FINI_ARRAYSZ: 1461 obj->fini_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1462 break; 1463 1464 case DT_DEBUG: 1465 if (!early) 1466 dbg("Filling in DT_DEBUG entry"); 1467 (__DECONST(Elf_Dyn *, dynp))->d_un.d_ptr = (Elf_Addr)&r_debug; 1468 break; 1469 1470 case DT_FLAGS: 1471 if (dynp->d_un.d_val & DF_ORIGIN) 1472 obj->z_origin = true; 1473 if (dynp->d_un.d_val & DF_SYMBOLIC) 1474 obj->symbolic = true; 1475 if (dynp->d_un.d_val & DF_TEXTREL) 1476 obj->textrel = true; 1477 if (dynp->d_un.d_val & DF_BIND_NOW) 1478 obj->bind_now = true; 1479 if (dynp->d_un.d_val & DF_STATIC_TLS) 1480 obj->static_tls = true; 1481 break; 1482 1483 #ifdef __powerpc__ 1484 #ifdef __powerpc64__ 1485 case DT_PPC64_GLINK: 1486 obj->glink = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1487 break; 1488 #else 1489 case DT_PPC_GOT: 1490 obj->gotptr = (Elf_Addr *)(obj->relocbase + dynp->d_un.d_ptr); 1491 break; 1492 #endif 1493 #endif 1494 1495 case DT_FLAGS_1: 1496 if (dynp->d_un.d_val & DF_1_NOOPEN) 1497 obj->z_noopen = true; 1498 if (dynp->d_un.d_val & DF_1_ORIGIN) 1499 obj->z_origin = true; 1500 if (dynp->d_un.d_val & DF_1_GLOBAL) 1501 obj->z_global = true; 1502 if (dynp->d_un.d_val & DF_1_BIND_NOW) 1503 obj->bind_now = true; 1504 if (dynp->d_un.d_val & DF_1_NODELETE) 1505 obj->z_nodelete = true; 1506 if (dynp->d_un.d_val & DF_1_LOADFLTR) 1507 obj->z_loadfltr = true; 1508 if (dynp->d_un.d_val & DF_1_INTERPOSE) 1509 obj->z_interpose = true; 1510 if (dynp->d_un.d_val & DF_1_NODEFLIB) 1511 obj->z_nodeflib = true; 1512 if (dynp->d_un.d_val & DF_1_PIE) 1513 obj->z_pie = true; 1514 break; 1515 1516 default: 1517 if (!early) { 1518 dbg("Ignoring d_tag %ld = %#lx", (long)dynp->d_tag, 1519 (long)dynp->d_tag); 1520 } 1521 break; 1522 } 1523 } 1524 1525 obj->traced = false; 1526 1527 if (plttype == DT_RELA) { 1528 obj->pltrela = (const Elf_Rela *) obj->pltrel; 1529 obj->pltrel = NULL; 1530 obj->pltrelasize = obj->pltrelsize; 1531 obj->pltrelsize = 0; 1532 } 1533 1534 /* Determine size of dynsym table (equal to nchains of sysv hash) */ 1535 if (obj->valid_hash_sysv) 1536 obj->dynsymcount = obj->nchains; 1537 else if (obj->valid_hash_gnu) { 1538 obj->dynsymcount = 0; 1539 for (bkt = 0; bkt < obj->nbuckets_gnu; bkt++) { 1540 if (obj->buckets_gnu[bkt] == 0) 1541 continue; 1542 hashval = &obj->chain_zero_gnu[obj->buckets_gnu[bkt]]; 1543 do 1544 obj->dynsymcount++; 1545 while ((*hashval++ & 1u) == 0); 1546 } 1547 obj->dynsymcount += obj->symndx_gnu; 1548 } 1549 1550 if (obj->linkmap.l_refname != NULL) 1551 obj->linkmap.l_refname = obj->strtab + (unsigned long)obj-> 1552 linkmap.l_refname; 1553 } 1554 1555 static bool 1556 obj_resolve_origin(Obj_Entry *obj) 1557 { 1558 1559 if (obj->origin_path != NULL) 1560 return (true); 1561 obj->origin_path = xmalloc(PATH_MAX); 1562 return (rtld_dirname_abs(obj->path, obj->origin_path) != -1); 1563 } 1564 1565 static bool 1566 digest_dynamic2(Obj_Entry *obj, const Elf_Dyn *dyn_rpath, 1567 const Elf_Dyn *dyn_soname, const Elf_Dyn *dyn_runpath) 1568 { 1569 1570 if (obj->z_origin && !obj_resolve_origin(obj)) 1571 return (false); 1572 1573 if (dyn_runpath != NULL) { 1574 obj->runpath = (const char *)obj->strtab + dyn_runpath->d_un.d_val; 1575 obj->runpath = origin_subst(obj, obj->runpath); 1576 } else if (dyn_rpath != NULL) { 1577 obj->rpath = (const char *)obj->strtab + dyn_rpath->d_un.d_val; 1578 obj->rpath = origin_subst(obj, obj->rpath); 1579 } 1580 if (dyn_soname != NULL) 1581 object_add_name(obj, obj->strtab + dyn_soname->d_un.d_val); 1582 return (true); 1583 } 1584 1585 static bool 1586 digest_dynamic(Obj_Entry *obj, int early) 1587 { 1588 const Elf_Dyn *dyn_rpath; 1589 const Elf_Dyn *dyn_soname; 1590 const Elf_Dyn *dyn_runpath; 1591 1592 digest_dynamic1(obj, early, &dyn_rpath, &dyn_soname, &dyn_runpath); 1593 return (digest_dynamic2(obj, dyn_rpath, dyn_soname, dyn_runpath)); 1594 } 1595 1596 /* 1597 * Process a shared object's program header. This is used only for the 1598 * main program, when the kernel has already loaded the main program 1599 * into memory before calling the dynamic linker. It creates and 1600 * returns an Obj_Entry structure. 1601 */ 1602 static Obj_Entry * 1603 digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path) 1604 { 1605 Obj_Entry *obj; 1606 const Elf_Phdr *phlimit = phdr + phnum; 1607 const Elf_Phdr *ph; 1608 Elf_Addr note_start, note_end; 1609 int nsegs = 0; 1610 1611 obj = obj_new(); 1612 for (ph = phdr; ph < phlimit; ph++) { 1613 if (ph->p_type != PT_PHDR) 1614 continue; 1615 1616 obj->phdr = phdr; 1617 obj->phsize = ph->p_memsz; 1618 obj->relocbase = __DECONST(char *, phdr) - ph->p_vaddr; 1619 break; 1620 } 1621 1622 obj->stack_flags = PF_X | PF_R | PF_W; 1623 1624 for (ph = phdr; ph < phlimit; ph++) { 1625 switch (ph->p_type) { 1626 1627 case PT_INTERP: 1628 obj->interp = (const char *)(ph->p_vaddr + obj->relocbase); 1629 break; 1630 1631 case PT_LOAD: 1632 if (nsegs == 0) { /* First load segment */ 1633 obj->vaddrbase = trunc_page(ph->p_vaddr); 1634 obj->mapbase = obj->vaddrbase + obj->relocbase; 1635 } else { /* Last load segment */ 1636 obj->mapsize = round_page(ph->p_vaddr + ph->p_memsz) - 1637 obj->vaddrbase; 1638 } 1639 nsegs++; 1640 break; 1641 1642 case PT_DYNAMIC: 1643 obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + obj->relocbase); 1644 break; 1645 1646 case PT_TLS: 1647 obj->tlsindex = 1; 1648 obj->tlssize = ph->p_memsz; 1649 obj->tlsalign = ph->p_align; 1650 obj->tlsinitsize = ph->p_filesz; 1651 obj->tlsinit = (void*)(ph->p_vaddr + obj->relocbase); 1652 obj->tlspoffset = ph->p_offset; 1653 break; 1654 1655 case PT_GNU_STACK: 1656 obj->stack_flags = ph->p_flags; 1657 break; 1658 1659 case PT_GNU_RELRO: 1660 obj->relro_page = obj->relocbase + trunc_page(ph->p_vaddr); 1661 obj->relro_size = trunc_page(ph->p_vaddr + ph->p_memsz) - 1662 trunc_page(ph->p_vaddr); 1663 break; 1664 1665 case PT_NOTE: 1666 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; 1667 note_end = note_start + ph->p_filesz; 1668 digest_notes(obj, note_start, note_end); 1669 break; 1670 } 1671 } 1672 if (nsegs < 1) { 1673 _rtld_error("%s: too few PT_LOAD segments", path); 1674 return (NULL); 1675 } 1676 1677 obj->entry = entry; 1678 return (obj); 1679 } 1680 1681 void 1682 digest_notes(Obj_Entry *obj, Elf_Addr note_start, Elf_Addr note_end) 1683 { 1684 const Elf_Note *note; 1685 const char *note_name; 1686 uintptr_t p; 1687 1688 for (note = (const Elf_Note *)note_start; (Elf_Addr)note < note_end; 1689 note = (const Elf_Note *)((const char *)(note + 1) + 1690 roundup2(note->n_namesz, sizeof(Elf32_Addr)) + 1691 roundup2(note->n_descsz, sizeof(Elf32_Addr)))) { 1692 if (note->n_namesz != sizeof(NOTE_FREEBSD_VENDOR) || 1693 note->n_descsz != sizeof(int32_t)) 1694 continue; 1695 if (note->n_type != NT_FREEBSD_ABI_TAG && 1696 note->n_type != NT_FREEBSD_FEATURE_CTL && 1697 note->n_type != NT_FREEBSD_NOINIT_TAG) 1698 continue; 1699 note_name = (const char *)(note + 1); 1700 if (strncmp(NOTE_FREEBSD_VENDOR, note_name, 1701 sizeof(NOTE_FREEBSD_VENDOR)) != 0) 1702 continue; 1703 switch (note->n_type) { 1704 case NT_FREEBSD_ABI_TAG: 1705 /* FreeBSD osrel note */ 1706 p = (uintptr_t)(note + 1); 1707 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1708 obj->osrel = *(const int32_t *)(p); 1709 dbg("note osrel %d", obj->osrel); 1710 break; 1711 case NT_FREEBSD_FEATURE_CTL: 1712 /* FreeBSD ABI feature control note */ 1713 p = (uintptr_t)(note + 1); 1714 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1715 obj->fctl0 = *(const uint32_t *)(p); 1716 dbg("note fctl0 %#x", obj->fctl0); 1717 break; 1718 case NT_FREEBSD_NOINIT_TAG: 1719 /* FreeBSD 'crt does not call init' note */ 1720 obj->crt_no_init = true; 1721 dbg("note crt_no_init"); 1722 break; 1723 } 1724 } 1725 } 1726 1727 static Obj_Entry * 1728 dlcheck(void *handle) 1729 { 1730 Obj_Entry *obj; 1731 1732 TAILQ_FOREACH(obj, &obj_list, next) { 1733 if (obj == (Obj_Entry *) handle) 1734 break; 1735 } 1736 1737 if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) { 1738 _rtld_error("Invalid shared object handle %p", handle); 1739 return (NULL); 1740 } 1741 return (obj); 1742 } 1743 1744 /* 1745 * If the given object is already in the donelist, return true. Otherwise 1746 * add the object to the list and return false. 1747 */ 1748 static bool 1749 donelist_check(DoneList *dlp, const Obj_Entry *obj) 1750 { 1751 unsigned int i; 1752 1753 for (i = 0; i < dlp->num_used; i++) 1754 if (dlp->objs[i] == obj) 1755 return (true); 1756 /* 1757 * Our donelist allocation should always be sufficient. But if 1758 * our threads locking isn't working properly, more shared objects 1759 * could have been loaded since we allocated the list. That should 1760 * never happen, but we'll handle it properly just in case it does. 1761 */ 1762 if (dlp->num_used < dlp->num_alloc) 1763 dlp->objs[dlp->num_used++] = obj; 1764 return (false); 1765 } 1766 1767 /* 1768 * Hash function for symbol table lookup. Don't even think about changing 1769 * this. It is specified by the System V ABI. 1770 */ 1771 unsigned long 1772 elf_hash(const char *name) 1773 { 1774 const unsigned char *p = (const unsigned char *) name; 1775 unsigned long h = 0; 1776 unsigned long g; 1777 1778 while (*p != '\0') { 1779 h = (h << 4) + *p++; 1780 if ((g = h & 0xf0000000) != 0) 1781 h ^= g >> 24; 1782 h &= ~g; 1783 } 1784 return (h); 1785 } 1786 1787 /* 1788 * The GNU hash function is the Daniel J. Bernstein hash clipped to 32 bits 1789 * unsigned in case it's implemented with a wider type. 1790 */ 1791 static uint32_t 1792 gnu_hash(const char *s) 1793 { 1794 uint32_t h; 1795 unsigned char c; 1796 1797 h = 5381; 1798 for (c = *s; c != '\0'; c = *++s) 1799 h = h * 33 + c; 1800 return (h & 0xffffffff); 1801 } 1802 1803 1804 /* 1805 * Find the library with the given name, and return its full pathname. 1806 * The returned string is dynamically allocated. Generates an error 1807 * message and returns NULL if the library cannot be found. 1808 * 1809 * If the second argument is non-NULL, then it refers to an already- 1810 * loaded shared object, whose library search path will be searched. 1811 * 1812 * If a library is successfully located via LD_LIBRARY_PATH_FDS, its 1813 * descriptor (which is close-on-exec) will be passed out via the third 1814 * argument. 1815 * 1816 * The search order is: 1817 * DT_RPATH in the referencing file _unless_ DT_RUNPATH is present (1) 1818 * DT_RPATH of the main object if DSO without defined DT_RUNPATH (1) 1819 * LD_LIBRARY_PATH 1820 * DT_RUNPATH in the referencing file 1821 * ldconfig hints (if -z nodefaultlib, filter out default library directories 1822 * from list) 1823 * /lib:/usr/lib _unless_ the referencing file is linked with -z nodefaultlib 1824 * 1825 * (1) Handled in digest_dynamic2 - rpath left NULL if runpath defined. 1826 */ 1827 static char * 1828 find_library(const char *xname, const Obj_Entry *refobj, int *fdp) 1829 { 1830 char *pathname, *refobj_path; 1831 const char *name; 1832 bool nodeflib, objgiven; 1833 1834 objgiven = refobj != NULL; 1835 1836 if (libmap_disable || !objgiven || 1837 (name = lm_find(refobj->path, xname)) == NULL) 1838 name = xname; 1839 1840 if (strchr(name, '/') != NULL) { /* Hard coded pathname */ 1841 if (name[0] != '/' && !trust) { 1842 _rtld_error("Absolute pathname required " 1843 "for shared object \"%s\"", name); 1844 return (NULL); 1845 } 1846 return (origin_subst(__DECONST(Obj_Entry *, refobj), 1847 __DECONST(char *, name))); 1848 } 1849 1850 dbg(" Searching for \"%s\"", name); 1851 refobj_path = objgiven ? refobj->path : NULL; 1852 1853 /* 1854 * If refobj->rpath != NULL, then refobj->runpath is NULL. Fall 1855 * back to pre-conforming behaviour if user requested so with 1856 * LD_LIBRARY_PATH_RPATH environment variable and ignore -z 1857 * nodeflib. 1858 */ 1859 if (objgiven && refobj->rpath != NULL && ld_library_path_rpath) { 1860 pathname = search_library_path(name, ld_library_path, 1861 refobj_path, fdp); 1862 if (pathname != NULL) 1863 return (pathname); 1864 if (refobj != NULL) { 1865 pathname = search_library_path(name, refobj->rpath, 1866 refobj_path, fdp); 1867 if (pathname != NULL) 1868 return (pathname); 1869 } 1870 pathname = search_library_pathfds(name, ld_library_dirs, fdp); 1871 if (pathname != NULL) 1872 return (pathname); 1873 pathname = search_library_path(name, gethints(false), 1874 refobj_path, fdp); 1875 if (pathname != NULL) 1876 return (pathname); 1877 pathname = search_library_path(name, ld_standard_library_path, 1878 refobj_path, fdp); 1879 if (pathname != NULL) 1880 return (pathname); 1881 } else { 1882 nodeflib = objgiven ? refobj->z_nodeflib : false; 1883 if (objgiven) { 1884 pathname = search_library_path(name, refobj->rpath, 1885 refobj->path, fdp); 1886 if (pathname != NULL) 1887 return (pathname); 1888 } 1889 if (objgiven && refobj->runpath == NULL && refobj != obj_main) { 1890 pathname = search_library_path(name, obj_main->rpath, 1891 refobj_path, fdp); 1892 if (pathname != NULL) 1893 return (pathname); 1894 } 1895 pathname = search_library_path(name, ld_library_path, 1896 refobj_path, fdp); 1897 if (pathname != NULL) 1898 return (pathname); 1899 if (objgiven) { 1900 pathname = search_library_path(name, refobj->runpath, 1901 refobj_path, fdp); 1902 if (pathname != NULL) 1903 return (pathname); 1904 } 1905 pathname = search_library_pathfds(name, ld_library_dirs, fdp); 1906 if (pathname != NULL) 1907 return (pathname); 1908 pathname = search_library_path(name, gethints(nodeflib), 1909 refobj_path, fdp); 1910 if (pathname != NULL) 1911 return (pathname); 1912 if (objgiven && !nodeflib) { 1913 pathname = search_library_path(name, 1914 ld_standard_library_path, refobj_path, fdp); 1915 if (pathname != NULL) 1916 return (pathname); 1917 } 1918 } 1919 1920 if (objgiven && refobj->path != NULL) { 1921 _rtld_error("Shared object \"%s\" not found, " 1922 "required by \"%s\"", name, basename(refobj->path)); 1923 } else { 1924 _rtld_error("Shared object \"%s\" not found", name); 1925 } 1926 return (NULL); 1927 } 1928 1929 /* 1930 * Given a symbol number in a referencing object, find the corresponding 1931 * definition of the symbol. Returns a pointer to the symbol, or NULL if 1932 * no definition was found. Returns a pointer to the Obj_Entry of the 1933 * defining object via the reference parameter DEFOBJ_OUT. 1934 */ 1935 const Elf_Sym * 1936 find_symdef(unsigned long symnum, const Obj_Entry *refobj, 1937 const Obj_Entry **defobj_out, int flags, SymCache *cache, 1938 RtldLockState *lockstate) 1939 { 1940 const Elf_Sym *ref; 1941 const Elf_Sym *def; 1942 const Obj_Entry *defobj; 1943 const Ver_Entry *ve; 1944 SymLook req; 1945 const char *name; 1946 int res; 1947 1948 /* 1949 * If we have already found this symbol, get the information from 1950 * the cache. 1951 */ 1952 if (symnum >= refobj->dynsymcount) 1953 return (NULL); /* Bad object */ 1954 if (cache != NULL && cache[symnum].sym != NULL) { 1955 *defobj_out = cache[symnum].obj; 1956 return (cache[symnum].sym); 1957 } 1958 1959 ref = refobj->symtab + symnum; 1960 name = refobj->strtab + ref->st_name; 1961 def = NULL; 1962 defobj = NULL; 1963 ve = NULL; 1964 1965 /* 1966 * We don't have to do a full scale lookup if the symbol is local. 1967 * We know it will bind to the instance in this load module; to 1968 * which we already have a pointer (ie ref). By not doing a lookup, 1969 * we not only improve performance, but it also avoids unresolvable 1970 * symbols when local symbols are not in the hash table. This has 1971 * been seen with the ia64 toolchain. 1972 */ 1973 if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) { 1974 if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) { 1975 _rtld_error("%s: Bogus symbol table entry %lu", refobj->path, 1976 symnum); 1977 } 1978 symlook_init(&req, name); 1979 req.flags = flags; 1980 ve = req.ventry = fetch_ventry(refobj, symnum); 1981 req.lockstate = lockstate; 1982 res = symlook_default(&req, refobj); 1983 if (res == 0) { 1984 def = req.sym_out; 1985 defobj = req.defobj_out; 1986 } 1987 } else { 1988 def = ref; 1989 defobj = refobj; 1990 } 1991 1992 /* 1993 * If we found no definition and the reference is weak, treat the 1994 * symbol as having the value zero. 1995 */ 1996 if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) { 1997 def = &sym_zero; 1998 defobj = obj_main; 1999 } 2000 2001 if (def != NULL) { 2002 *defobj_out = defobj; 2003 /* Record the information in the cache to avoid subsequent lookups. */ 2004 if (cache != NULL) { 2005 cache[symnum].sym = def; 2006 cache[symnum].obj = defobj; 2007 } 2008 } else { 2009 if (refobj != &obj_rtld) 2010 _rtld_error("%s: Undefined symbol \"%s%s%s\"", refobj->path, name, 2011 ve != NULL ? "@" : "", ve != NULL ? ve->name : ""); 2012 } 2013 return (def); 2014 } 2015 2016 /* 2017 * Return the search path from the ldconfig hints file, reading it if 2018 * necessary. If nostdlib is true, then the default search paths are 2019 * not added to result. 2020 * 2021 * Returns NULL if there are problems with the hints file, 2022 * or if the search path there is empty. 2023 */ 2024 static const char * 2025 gethints(bool nostdlib) 2026 { 2027 static char *filtered_path; 2028 static const char *hints; 2029 static struct elfhints_hdr hdr; 2030 struct fill_search_info_args sargs, hargs; 2031 struct dl_serinfo smeta, hmeta, *SLPinfo, *hintinfo; 2032 struct dl_serpath *SLPpath, *hintpath; 2033 char *p; 2034 struct stat hint_stat; 2035 unsigned int SLPndx, hintndx, fndx, fcount; 2036 int fd; 2037 size_t flen; 2038 uint32_t dl; 2039 bool skip; 2040 2041 /* First call, read the hints file */ 2042 if (hints == NULL) { 2043 /* Keep from trying again in case the hints file is bad. */ 2044 hints = ""; 2045 2046 if ((fd = open(ld_elf_hints_path, O_RDONLY | O_CLOEXEC)) == -1) 2047 return (NULL); 2048 2049 /* 2050 * Check of hdr.dirlistlen value against type limit 2051 * intends to pacify static analyzers. Further 2052 * paranoia leads to checks that dirlist is fully 2053 * contained in the file range. 2054 */ 2055 if (read(fd, &hdr, sizeof hdr) != sizeof hdr || 2056 hdr.magic != ELFHINTS_MAGIC || 2057 hdr.version != 1 || hdr.dirlistlen > UINT_MAX / 2 || 2058 fstat(fd, &hint_stat) == -1) { 2059 cleanup1: 2060 close(fd); 2061 hdr.dirlistlen = 0; 2062 return (NULL); 2063 } 2064 dl = hdr.strtab; 2065 if (dl + hdr.dirlist < dl) 2066 goto cleanup1; 2067 dl += hdr.dirlist; 2068 if (dl + hdr.dirlistlen < dl) 2069 goto cleanup1; 2070 dl += hdr.dirlistlen; 2071 if (dl > hint_stat.st_size) 2072 goto cleanup1; 2073 p = xmalloc(hdr.dirlistlen + 1); 2074 if (pread(fd, p, hdr.dirlistlen + 1, 2075 hdr.strtab + hdr.dirlist) != (ssize_t)hdr.dirlistlen + 1 || 2076 p[hdr.dirlistlen] != '\0') { 2077 free(p); 2078 goto cleanup1; 2079 } 2080 hints = p; 2081 close(fd); 2082 } 2083 2084 /* 2085 * If caller agreed to receive list which includes the default 2086 * paths, we are done. Otherwise, if we still did not 2087 * calculated filtered result, do it now. 2088 */ 2089 if (!nostdlib) 2090 return (hints[0] != '\0' ? hints : NULL); 2091 if (filtered_path != NULL) 2092 goto filt_ret; 2093 2094 /* 2095 * Obtain the list of all configured search paths, and the 2096 * list of the default paths. 2097 * 2098 * First estimate the size of the results. 2099 */ 2100 smeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 2101 smeta.dls_cnt = 0; 2102 hmeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 2103 hmeta.dls_cnt = 0; 2104 2105 sargs.request = RTLD_DI_SERINFOSIZE; 2106 sargs.serinfo = &smeta; 2107 hargs.request = RTLD_DI_SERINFOSIZE; 2108 hargs.serinfo = &hmeta; 2109 2110 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 2111 &sargs); 2112 path_enumerate(hints, fill_search_info, NULL, &hargs); 2113 2114 SLPinfo = xmalloc(smeta.dls_size); 2115 hintinfo = xmalloc(hmeta.dls_size); 2116 2117 /* 2118 * Next fetch both sets of paths. 2119 */ 2120 sargs.request = RTLD_DI_SERINFO; 2121 sargs.serinfo = SLPinfo; 2122 sargs.serpath = &SLPinfo->dls_serpath[0]; 2123 sargs.strspace = (char *)&SLPinfo->dls_serpath[smeta.dls_cnt]; 2124 2125 hargs.request = RTLD_DI_SERINFO; 2126 hargs.serinfo = hintinfo; 2127 hargs.serpath = &hintinfo->dls_serpath[0]; 2128 hargs.strspace = (char *)&hintinfo->dls_serpath[hmeta.dls_cnt]; 2129 2130 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 2131 &sargs); 2132 path_enumerate(hints, fill_search_info, NULL, &hargs); 2133 2134 /* 2135 * Now calculate the difference between two sets, by excluding 2136 * standard paths from the full set. 2137 */ 2138 fndx = 0; 2139 fcount = 0; 2140 filtered_path = xmalloc(hdr.dirlistlen + 1); 2141 hintpath = &hintinfo->dls_serpath[0]; 2142 for (hintndx = 0; hintndx < hmeta.dls_cnt; hintndx++, hintpath++) { 2143 skip = false; 2144 SLPpath = &SLPinfo->dls_serpath[0]; 2145 /* 2146 * Check each standard path against current. 2147 */ 2148 for (SLPndx = 0; SLPndx < smeta.dls_cnt; SLPndx++, SLPpath++) { 2149 /* matched, skip the path */ 2150 if (!strcmp(hintpath->dls_name, SLPpath->dls_name)) { 2151 skip = true; 2152 break; 2153 } 2154 } 2155 if (skip) 2156 continue; 2157 /* 2158 * Not matched against any standard path, add the path 2159 * to result. Separate consequtive paths with ':'. 2160 */ 2161 if (fcount > 0) { 2162 filtered_path[fndx] = ':'; 2163 fndx++; 2164 } 2165 fcount++; 2166 flen = strlen(hintpath->dls_name); 2167 strncpy((filtered_path + fndx), hintpath->dls_name, flen); 2168 fndx += flen; 2169 } 2170 filtered_path[fndx] = '\0'; 2171 2172 free(SLPinfo); 2173 free(hintinfo); 2174 2175 filt_ret: 2176 return (filtered_path[0] != '\0' ? filtered_path : NULL); 2177 } 2178 2179 static void 2180 init_dag(Obj_Entry *root) 2181 { 2182 const Needed_Entry *needed; 2183 const Objlist_Entry *elm; 2184 DoneList donelist; 2185 2186 if (root->dag_inited) 2187 return; 2188 donelist_init(&donelist); 2189 2190 /* Root object belongs to own DAG. */ 2191 objlist_push_tail(&root->dldags, root); 2192 objlist_push_tail(&root->dagmembers, root); 2193 donelist_check(&donelist, root); 2194 2195 /* 2196 * Add dependencies of root object to DAG in breadth order 2197 * by exploiting the fact that each new object get added 2198 * to the tail of the dagmembers list. 2199 */ 2200 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2201 for (needed = elm->obj->needed; needed != NULL; needed = needed->next) { 2202 if (needed->obj == NULL || donelist_check(&donelist, needed->obj)) 2203 continue; 2204 objlist_push_tail(&needed->obj->dldags, root); 2205 objlist_push_tail(&root->dagmembers, needed->obj); 2206 } 2207 } 2208 root->dag_inited = true; 2209 } 2210 2211 static void 2212 init_marker(Obj_Entry *marker) 2213 { 2214 2215 bzero(marker, sizeof(*marker)); 2216 marker->marker = true; 2217 } 2218 2219 Obj_Entry * 2220 globallist_curr(const Obj_Entry *obj) 2221 { 2222 2223 for (;;) { 2224 if (obj == NULL) 2225 return (NULL); 2226 if (!obj->marker) 2227 return (__DECONST(Obj_Entry *, obj)); 2228 obj = TAILQ_PREV(obj, obj_entry_q, next); 2229 } 2230 } 2231 2232 Obj_Entry * 2233 globallist_next(const Obj_Entry *obj) 2234 { 2235 2236 for (;;) { 2237 obj = TAILQ_NEXT(obj, next); 2238 if (obj == NULL) 2239 return (NULL); 2240 if (!obj->marker) 2241 return (__DECONST(Obj_Entry *, obj)); 2242 } 2243 } 2244 2245 /* Prevent the object from being unmapped while the bind lock is dropped. */ 2246 static void 2247 hold_object(Obj_Entry *obj) 2248 { 2249 2250 obj->holdcount++; 2251 } 2252 2253 static void 2254 unhold_object(Obj_Entry *obj) 2255 { 2256 2257 assert(obj->holdcount > 0); 2258 if (--obj->holdcount == 0 && obj->unholdfree) 2259 release_object(obj); 2260 } 2261 2262 static void 2263 process_z(Obj_Entry *root) 2264 { 2265 const Objlist_Entry *elm; 2266 Obj_Entry *obj; 2267 2268 /* 2269 * Walk over object DAG and process every dependent object 2270 * that is marked as DF_1_NODELETE or DF_1_GLOBAL. They need 2271 * to grow their own DAG. 2272 * 2273 * For DF_1_GLOBAL, DAG is required for symbol lookups in 2274 * symlook_global() to work. 2275 * 2276 * For DF_1_NODELETE, the DAG should have its reference upped. 2277 */ 2278 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2279 obj = elm->obj; 2280 if (obj == NULL) 2281 continue; 2282 if (obj->z_nodelete && !obj->ref_nodel) { 2283 dbg("obj %s -z nodelete", obj->path); 2284 init_dag(obj); 2285 ref_dag(obj); 2286 obj->ref_nodel = true; 2287 } 2288 if (obj->z_global && objlist_find(&list_global, obj) == NULL) { 2289 dbg("obj %s -z global", obj->path); 2290 objlist_push_tail(&list_global, obj); 2291 init_dag(obj); 2292 } 2293 } 2294 } 2295 2296 static void 2297 parse_rtld_phdr(Obj_Entry *obj) 2298 { 2299 const Elf_Phdr *ph; 2300 Elf_Addr note_start, note_end; 2301 2302 obj->stack_flags = PF_X | PF_R | PF_W; 2303 for (ph = obj->phdr; (const char *)ph < (const char *)obj->phdr + 2304 obj->phsize; ph++) { 2305 switch (ph->p_type) { 2306 case PT_GNU_STACK: 2307 obj->stack_flags = ph->p_flags; 2308 break; 2309 case PT_GNU_RELRO: 2310 obj->relro_page = obj->relocbase + 2311 trunc_page(ph->p_vaddr); 2312 obj->relro_size = round_page(ph->p_memsz); 2313 break; 2314 case PT_NOTE: 2315 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; 2316 note_end = note_start + ph->p_filesz; 2317 digest_notes(obj, note_start, note_end); 2318 break; 2319 } 2320 } 2321 } 2322 2323 /* 2324 * Initialize the dynamic linker. The argument is the address at which 2325 * the dynamic linker has been mapped into memory. The primary task of 2326 * this function is to relocate the dynamic linker. 2327 */ 2328 static void 2329 init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info) 2330 { 2331 Obj_Entry objtmp; /* Temporary rtld object */ 2332 const Elf_Ehdr *ehdr; 2333 const Elf_Dyn *dyn_rpath; 2334 const Elf_Dyn *dyn_soname; 2335 const Elf_Dyn *dyn_runpath; 2336 2337 #ifdef RTLD_INIT_PAGESIZES_EARLY 2338 /* The page size is required by the dynamic memory allocator. */ 2339 init_pagesizes(aux_info); 2340 #endif 2341 2342 /* 2343 * Conjure up an Obj_Entry structure for the dynamic linker. 2344 * 2345 * The "path" member can't be initialized yet because string constants 2346 * cannot yet be accessed. Below we will set it correctly. 2347 */ 2348 memset(&objtmp, 0, sizeof(objtmp)); 2349 objtmp.path = NULL; 2350 objtmp.rtld = true; 2351 objtmp.mapbase = mapbase; 2352 #ifdef PIC 2353 objtmp.relocbase = mapbase; 2354 #endif 2355 2356 objtmp.dynamic = rtld_dynamic(&objtmp); 2357 digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname, &dyn_runpath); 2358 assert(objtmp.needed == NULL); 2359 #if !defined(__mips__) 2360 /* MIPS has a bogus DT_TEXTREL. */ 2361 assert(!objtmp.textrel); 2362 #endif 2363 /* 2364 * Temporarily put the dynamic linker entry into the object list, so 2365 * that symbols can be found. 2366 */ 2367 relocate_objects(&objtmp, true, &objtmp, 0, NULL); 2368 2369 ehdr = (Elf_Ehdr *)mapbase; 2370 objtmp.phdr = (Elf_Phdr *)((char *)mapbase + ehdr->e_phoff); 2371 objtmp.phsize = ehdr->e_phnum * sizeof(objtmp.phdr[0]); 2372 2373 /* Initialize the object list. */ 2374 TAILQ_INIT(&obj_list); 2375 2376 /* Now that non-local variables can be accesses, copy out obj_rtld. */ 2377 memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld)); 2378 2379 #ifndef RTLD_INIT_PAGESIZES_EARLY 2380 /* The page size is required by the dynamic memory allocator. */ 2381 init_pagesizes(aux_info); 2382 #endif 2383 2384 if (aux_info[AT_OSRELDATE] != NULL) 2385 osreldate = aux_info[AT_OSRELDATE]->a_un.a_val; 2386 2387 digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname, dyn_runpath); 2388 2389 /* Replace the path with a dynamically allocated copy. */ 2390 obj_rtld.path = xstrdup(ld_path_rtld); 2391 2392 parse_rtld_phdr(&obj_rtld); 2393 if (obj_enforce_relro(&obj_rtld) == -1) 2394 rtld_die(); 2395 2396 r_debug.r_version = R_DEBUG_VERSION; 2397 r_debug.r_brk = r_debug_state; 2398 r_debug.r_state = RT_CONSISTENT; 2399 r_debug.r_ldbase = obj_rtld.relocbase; 2400 } 2401 2402 /* 2403 * Retrieve the array of supported page sizes. The kernel provides the page 2404 * sizes in increasing order. 2405 */ 2406 static void 2407 init_pagesizes(Elf_Auxinfo **aux_info) 2408 { 2409 static size_t psa[MAXPAGESIZES]; 2410 int mib[2]; 2411 size_t len, size; 2412 2413 if (aux_info[AT_PAGESIZES] != NULL && aux_info[AT_PAGESIZESLEN] != 2414 NULL) { 2415 size = aux_info[AT_PAGESIZESLEN]->a_un.a_val; 2416 pagesizes = aux_info[AT_PAGESIZES]->a_un.a_ptr; 2417 } else { 2418 len = 2; 2419 if (sysctlnametomib("hw.pagesizes", mib, &len) == 0) 2420 size = sizeof(psa); 2421 else { 2422 /* As a fallback, retrieve the base page size. */ 2423 size = sizeof(psa[0]); 2424 if (aux_info[AT_PAGESZ] != NULL) { 2425 psa[0] = aux_info[AT_PAGESZ]->a_un.a_val; 2426 goto psa_filled; 2427 } else { 2428 mib[0] = CTL_HW; 2429 mib[1] = HW_PAGESIZE; 2430 len = 2; 2431 } 2432 } 2433 if (sysctl(mib, len, psa, &size, NULL, 0) == -1) { 2434 _rtld_error("sysctl for hw.pagesize(s) failed"); 2435 rtld_die(); 2436 } 2437 psa_filled: 2438 pagesizes = psa; 2439 } 2440 npagesizes = size / sizeof(pagesizes[0]); 2441 /* Discard any invalid entries at the end of the array. */ 2442 while (npagesizes > 0 && pagesizes[npagesizes - 1] == 0) 2443 npagesizes--; 2444 } 2445 2446 /* 2447 * Add the init functions from a needed object list (and its recursive 2448 * needed objects) to "list". This is not used directly; it is a helper 2449 * function for initlist_add_objects(). The write lock must be held 2450 * when this function is called. 2451 */ 2452 static void 2453 initlist_add_neededs(Needed_Entry *needed, Objlist *list) 2454 { 2455 /* Recursively process the successor needed objects. */ 2456 if (needed->next != NULL) 2457 initlist_add_neededs(needed->next, list); 2458 2459 /* Process the current needed object. */ 2460 if (needed->obj != NULL) 2461 initlist_add_objects(needed->obj, needed->obj, list); 2462 } 2463 2464 /* 2465 * Scan all of the DAGs rooted in the range of objects from "obj" to 2466 * "tail" and add their init functions to "list". This recurses over 2467 * the DAGs and ensure the proper init ordering such that each object's 2468 * needed libraries are initialized before the object itself. At the 2469 * same time, this function adds the objects to the global finalization 2470 * list "list_fini" in the opposite order. The write lock must be 2471 * held when this function is called. 2472 */ 2473 static void 2474 initlist_add_objects(Obj_Entry *obj, Obj_Entry *tail, Objlist *list) 2475 { 2476 Obj_Entry *nobj; 2477 2478 if (obj->init_scanned || obj->init_done) 2479 return; 2480 obj->init_scanned = true; 2481 2482 /* Recursively process the successor objects. */ 2483 nobj = globallist_next(obj); 2484 if (nobj != NULL && obj != tail) 2485 initlist_add_objects(nobj, tail, list); 2486 2487 /* Recursively process the needed objects. */ 2488 if (obj->needed != NULL) 2489 initlist_add_neededs(obj->needed, list); 2490 if (obj->needed_filtees != NULL) 2491 initlist_add_neededs(obj->needed_filtees, list); 2492 if (obj->needed_aux_filtees != NULL) 2493 initlist_add_neededs(obj->needed_aux_filtees, list); 2494 2495 /* Add the object to the init list. */ 2496 objlist_push_tail(list, obj); 2497 2498 /* Add the object to the global fini list in the reverse order. */ 2499 if ((obj->fini != (Elf_Addr)NULL || obj->fini_array != (Elf_Addr)NULL) 2500 && !obj->on_fini_list) { 2501 objlist_push_head(&list_fini, obj); 2502 obj->on_fini_list = true; 2503 } 2504 } 2505 2506 #ifndef FPTR_TARGET 2507 #define FPTR_TARGET(f) ((Elf_Addr) (f)) 2508 #endif 2509 2510 static void 2511 free_needed_filtees(Needed_Entry *n, RtldLockState *lockstate) 2512 { 2513 Needed_Entry *needed, *needed1; 2514 2515 for (needed = n; needed != NULL; needed = needed->next) { 2516 if (needed->obj != NULL) { 2517 dlclose_locked(needed->obj, lockstate); 2518 needed->obj = NULL; 2519 } 2520 } 2521 for (needed = n; needed != NULL; needed = needed1) { 2522 needed1 = needed->next; 2523 free(needed); 2524 } 2525 } 2526 2527 static void 2528 unload_filtees(Obj_Entry *obj, RtldLockState *lockstate) 2529 { 2530 2531 free_needed_filtees(obj->needed_filtees, lockstate); 2532 obj->needed_filtees = NULL; 2533 free_needed_filtees(obj->needed_aux_filtees, lockstate); 2534 obj->needed_aux_filtees = NULL; 2535 obj->filtees_loaded = false; 2536 } 2537 2538 static void 2539 load_filtee1(Obj_Entry *obj, Needed_Entry *needed, int flags, 2540 RtldLockState *lockstate) 2541 { 2542 2543 for (; needed != NULL; needed = needed->next) { 2544 needed->obj = dlopen_object(obj->strtab + needed->name, -1, obj, 2545 flags, ((ld_loadfltr || obj->z_loadfltr) ? RTLD_NOW : RTLD_LAZY) | 2546 RTLD_LOCAL, lockstate); 2547 } 2548 } 2549 2550 static void 2551 load_filtees(Obj_Entry *obj, int flags, RtldLockState *lockstate) 2552 { 2553 2554 lock_restart_for_upgrade(lockstate); 2555 if (!obj->filtees_loaded) { 2556 load_filtee1(obj, obj->needed_filtees, flags, lockstate); 2557 load_filtee1(obj, obj->needed_aux_filtees, flags, lockstate); 2558 obj->filtees_loaded = true; 2559 } 2560 } 2561 2562 static int 2563 process_needed(Obj_Entry *obj, Needed_Entry *needed, int flags) 2564 { 2565 Obj_Entry *obj1; 2566 2567 for (; needed != NULL; needed = needed->next) { 2568 obj1 = needed->obj = load_object(obj->strtab + needed->name, -1, obj, 2569 flags & ~RTLD_LO_NOLOAD); 2570 if (obj1 == NULL && !ld_tracing && (flags & RTLD_LO_FILTEES) == 0) 2571 return (-1); 2572 } 2573 return (0); 2574 } 2575 2576 /* 2577 * Given a shared object, traverse its list of needed objects, and load 2578 * each of them. Returns 0 on success. Generates an error message and 2579 * returns -1 on failure. 2580 */ 2581 static int 2582 load_needed_objects(Obj_Entry *first, int flags) 2583 { 2584 Obj_Entry *obj; 2585 2586 for (obj = first; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 2587 if (obj->marker) 2588 continue; 2589 if (process_needed(obj, obj->needed, flags) == -1) 2590 return (-1); 2591 } 2592 return (0); 2593 } 2594 2595 static int 2596 load_preload_objects(const char *penv, bool isfd) 2597 { 2598 Obj_Entry *obj; 2599 const char *name; 2600 size_t len; 2601 char savech, *p, *psave; 2602 int fd; 2603 static const char delim[] = " \t:;"; 2604 2605 if (penv == NULL) 2606 return (0); 2607 2608 p = psave = xstrdup(penv); 2609 p += strspn(p, delim); 2610 while (*p != '\0') { 2611 len = strcspn(p, delim); 2612 2613 savech = p[len]; 2614 p[len] = '\0'; 2615 if (isfd) { 2616 name = NULL; 2617 fd = parse_integer(p); 2618 if (fd == -1) { 2619 free(psave); 2620 return (-1); 2621 } 2622 } else { 2623 name = p; 2624 fd = -1; 2625 } 2626 2627 obj = load_object(name, fd, NULL, 0); 2628 if (obj == NULL) { 2629 free(psave); 2630 return (-1); /* XXX - cleanup */ 2631 } 2632 obj->z_interpose = true; 2633 p[len] = savech; 2634 p += len; 2635 p += strspn(p, delim); 2636 } 2637 LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL); 2638 2639 free(psave); 2640 return (0); 2641 } 2642 2643 static const char * 2644 printable_path(const char *path) 2645 { 2646 2647 return (path == NULL ? "<unknown>" : path); 2648 } 2649 2650 /* 2651 * Load a shared object into memory, if it is not already loaded. The 2652 * object may be specified by name or by user-supplied file descriptor 2653 * fd_u. In the later case, the fd_u descriptor is not closed, but its 2654 * duplicate is. 2655 * 2656 * Returns a pointer to the Obj_Entry for the object. Returns NULL 2657 * on failure. 2658 */ 2659 static Obj_Entry * 2660 load_object(const char *name, int fd_u, const Obj_Entry *refobj, int flags) 2661 { 2662 Obj_Entry *obj; 2663 int fd; 2664 struct stat sb; 2665 char *path; 2666 2667 fd = -1; 2668 if (name != NULL) { 2669 TAILQ_FOREACH(obj, &obj_list, next) { 2670 if (obj->marker || obj->doomed) 2671 continue; 2672 if (object_match_name(obj, name)) 2673 return (obj); 2674 } 2675 2676 path = find_library(name, refobj, &fd); 2677 if (path == NULL) 2678 return (NULL); 2679 } else 2680 path = NULL; 2681 2682 if (fd >= 0) { 2683 /* 2684 * search_library_pathfds() opens a fresh file descriptor for the 2685 * library, so there is no need to dup(). 2686 */ 2687 } else if (fd_u == -1) { 2688 /* 2689 * If we didn't find a match by pathname, or the name is not 2690 * supplied, open the file and check again by device and inode. 2691 * This avoids false mismatches caused by multiple links or ".." 2692 * in pathnames. 2693 * 2694 * To avoid a race, we open the file and use fstat() rather than 2695 * using stat(). 2696 */ 2697 if ((fd = open(path, O_RDONLY | O_CLOEXEC | O_VERIFY)) == -1) { 2698 _rtld_error("Cannot open \"%s\"", path); 2699 free(path); 2700 return (NULL); 2701 } 2702 } else { 2703 fd = fcntl(fd_u, F_DUPFD_CLOEXEC, 0); 2704 if (fd == -1) { 2705 _rtld_error("Cannot dup fd"); 2706 free(path); 2707 return (NULL); 2708 } 2709 } 2710 if (fstat(fd, &sb) == -1) { 2711 _rtld_error("Cannot fstat \"%s\"", printable_path(path)); 2712 close(fd); 2713 free(path); 2714 return (NULL); 2715 } 2716 TAILQ_FOREACH(obj, &obj_list, next) { 2717 if (obj->marker || obj->doomed) 2718 continue; 2719 if (obj->ino == sb.st_ino && obj->dev == sb.st_dev) 2720 break; 2721 } 2722 if (obj != NULL && name != NULL) { 2723 object_add_name(obj, name); 2724 free(path); 2725 close(fd); 2726 return (obj); 2727 } 2728 if (flags & RTLD_LO_NOLOAD) { 2729 free(path); 2730 close(fd); 2731 return (NULL); 2732 } 2733 2734 /* First use of this object, so we must map it in */ 2735 obj = do_load_object(fd, name, path, &sb, flags); 2736 if (obj == NULL) 2737 free(path); 2738 close(fd); 2739 2740 return (obj); 2741 } 2742 2743 static Obj_Entry * 2744 do_load_object(int fd, const char *name, char *path, struct stat *sbp, 2745 int flags) 2746 { 2747 Obj_Entry *obj; 2748 struct statfs fs; 2749 2750 /* 2751 * First, make sure that environment variables haven't been 2752 * used to circumvent the noexec flag on a filesystem. 2753 * We ignore fstatfs(2) failures, since fd might reference 2754 * not a file, e.g. shmfd. 2755 */ 2756 if (dangerous_ld_env && fstatfs(fd, &fs) == 0 && 2757 (fs.f_flags & MNT_NOEXEC) != 0) { 2758 _rtld_error("Cannot execute objects on %s", fs.f_mntonname); 2759 return (NULL); 2760 } 2761 2762 dbg("loading \"%s\"", printable_path(path)); 2763 obj = map_object(fd, printable_path(path), sbp); 2764 if (obj == NULL) 2765 return (NULL); 2766 2767 /* 2768 * If DT_SONAME is present in the object, digest_dynamic2 already 2769 * added it to the object names. 2770 */ 2771 if (name != NULL) 2772 object_add_name(obj, name); 2773 obj->path = path; 2774 if (!digest_dynamic(obj, 0)) 2775 goto errp; 2776 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", obj->path, 2777 obj->valid_hash_sysv, obj->valid_hash_gnu, obj->dynsymcount); 2778 if (obj->z_pie && (flags & RTLD_LO_TRACE) == 0) { 2779 dbg("refusing to load PIE executable \"%s\"", obj->path); 2780 _rtld_error("Cannot load PIE binary %s as DSO", obj->path); 2781 goto errp; 2782 } 2783 if (obj->z_noopen && (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) == 2784 RTLD_LO_DLOPEN) { 2785 dbg("refusing to load non-loadable \"%s\"", obj->path); 2786 _rtld_error("Cannot dlopen non-loadable %s", obj->path); 2787 goto errp; 2788 } 2789 2790 obj->dlopened = (flags & RTLD_LO_DLOPEN) != 0; 2791 TAILQ_INSERT_TAIL(&obj_list, obj, next); 2792 obj_count++; 2793 obj_loads++; 2794 linkmap_add(obj); /* for GDB & dlinfo() */ 2795 max_stack_flags |= obj->stack_flags; 2796 2797 dbg(" %p .. %p: %s", obj->mapbase, 2798 obj->mapbase + obj->mapsize - 1, obj->path); 2799 if (obj->textrel) 2800 dbg(" WARNING: %s has impure text", obj->path); 2801 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 2802 obj->path); 2803 2804 return (obj); 2805 2806 errp: 2807 munmap(obj->mapbase, obj->mapsize); 2808 obj_free(obj); 2809 return (NULL); 2810 } 2811 2812 static int 2813 load_kpreload(const void *addr) 2814 { 2815 Obj_Entry *obj; 2816 const Elf_Ehdr *ehdr; 2817 const Elf_Phdr *phdr, *phlimit, *phdyn, *seg0, *segn; 2818 static const char kname[] = "[vdso]"; 2819 2820 ehdr = addr; 2821 if (!check_elf_headers(ehdr, "kpreload")) 2822 return (-1); 2823 obj = obj_new(); 2824 phdr = (const Elf_Phdr *)((const char *)addr + ehdr->e_phoff); 2825 obj->phdr = phdr; 2826 obj->phsize = ehdr->e_phnum * sizeof(*phdr); 2827 phlimit = phdr + ehdr->e_phnum; 2828 seg0 = segn = NULL; 2829 2830 for (; phdr < phlimit; phdr++) { 2831 switch (phdr->p_type) { 2832 case PT_DYNAMIC: 2833 phdyn = phdr; 2834 break; 2835 case PT_GNU_STACK: 2836 /* Absense of PT_GNU_STACK implies stack_flags == 0. */ 2837 obj->stack_flags = phdr->p_flags; 2838 break; 2839 case PT_LOAD: 2840 if (seg0 == NULL || seg0->p_vaddr > phdr->p_vaddr) 2841 seg0 = phdr; 2842 if (segn == NULL || segn->p_vaddr + segn->p_memsz < 2843 phdr->p_vaddr + phdr->p_memsz) 2844 segn = phdr; 2845 break; 2846 } 2847 } 2848 2849 obj->mapbase = __DECONST(caddr_t, addr); 2850 obj->mapsize = segn->p_vaddr + segn->p_memsz - (Elf_Addr)addr; 2851 obj->vaddrbase = 0; 2852 obj->relocbase = obj->mapbase; 2853 2854 object_add_name(obj, kname); 2855 obj->path = xstrdup(kname); 2856 obj->dynamic = (const Elf_Dyn *)(obj->relocbase + phdyn->p_vaddr); 2857 2858 if (!digest_dynamic(obj, 0)) { 2859 obj_free(obj); 2860 return (-1); 2861 } 2862 2863 /* 2864 * We assume that kernel-preloaded object does not need 2865 * relocation. It is currently written into read-only page, 2866 * handling relocations would mean we need to allocate at 2867 * least one additional page per AS. 2868 */ 2869 dbg("%s mapbase %p phdrs %p PT_LOAD phdr %p vaddr %p dynamic %p", 2870 obj->path, obj->mapbase, obj->phdr, seg0, 2871 obj->relocbase + seg0->p_vaddr, obj->dynamic); 2872 2873 TAILQ_INSERT_TAIL(&obj_list, obj, next); 2874 obj_count++; 2875 obj_loads++; 2876 linkmap_add(obj); /* for GDB & dlinfo() */ 2877 max_stack_flags |= obj->stack_flags; 2878 2879 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, 0, 0, obj->path); 2880 return (0); 2881 } 2882 2883 Obj_Entry * 2884 obj_from_addr(const void *addr) 2885 { 2886 Obj_Entry *obj; 2887 2888 TAILQ_FOREACH(obj, &obj_list, next) { 2889 if (obj->marker) 2890 continue; 2891 if (addr < (void *) obj->mapbase) 2892 continue; 2893 if (addr < (void *)(obj->mapbase + obj->mapsize)) 2894 return obj; 2895 } 2896 return (NULL); 2897 } 2898 2899 static void 2900 preinit_main(void) 2901 { 2902 Elf_Addr *preinit_addr; 2903 int index; 2904 2905 preinit_addr = (Elf_Addr *)obj_main->preinit_array; 2906 if (preinit_addr == NULL) 2907 return; 2908 2909 for (index = 0; index < obj_main->preinit_array_num; index++) { 2910 if (preinit_addr[index] != 0 && preinit_addr[index] != 1) { 2911 dbg("calling preinit function for %s at %p", obj_main->path, 2912 (void *)preinit_addr[index]); 2913 LD_UTRACE(UTRACE_INIT_CALL, obj_main, (void *)preinit_addr[index], 2914 0, 0, obj_main->path); 2915 call_init_pointer(obj_main, preinit_addr[index]); 2916 } 2917 } 2918 } 2919 2920 /* 2921 * Call the finalization functions for each of the objects in "list" 2922 * belonging to the DAG of "root" and referenced once. If NULL "root" 2923 * is specified, every finalization function will be called regardless 2924 * of the reference count and the list elements won't be freed. All of 2925 * the objects are expected to have non-NULL fini functions. 2926 */ 2927 static void 2928 objlist_call_fini(Objlist *list, Obj_Entry *root, RtldLockState *lockstate) 2929 { 2930 Objlist_Entry *elm; 2931 struct dlerror_save *saved_msg; 2932 Elf_Addr *fini_addr; 2933 int index; 2934 2935 assert(root == NULL || root->refcount == 1); 2936 2937 if (root != NULL) 2938 root->doomed = true; 2939 2940 /* 2941 * Preserve the current error message since a fini function might 2942 * call into the dynamic linker and overwrite it. 2943 */ 2944 saved_msg = errmsg_save(); 2945 do { 2946 STAILQ_FOREACH(elm, list, link) { 2947 if (root != NULL && (elm->obj->refcount != 1 || 2948 objlist_find(&root->dagmembers, elm->obj) == NULL)) 2949 continue; 2950 /* Remove object from fini list to prevent recursive invocation. */ 2951 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 2952 /* Ensure that new references cannot be acquired. */ 2953 elm->obj->doomed = true; 2954 2955 hold_object(elm->obj); 2956 lock_release(rtld_bind_lock, lockstate); 2957 /* 2958 * It is legal to have both DT_FINI and DT_FINI_ARRAY defined. 2959 * When this happens, DT_FINI_ARRAY is processed first. 2960 */ 2961 fini_addr = (Elf_Addr *)elm->obj->fini_array; 2962 if (fini_addr != NULL && elm->obj->fini_array_num > 0) { 2963 for (index = elm->obj->fini_array_num - 1; index >= 0; 2964 index--) { 2965 if (fini_addr[index] != 0 && fini_addr[index] != 1) { 2966 dbg("calling fini function for %s at %p", 2967 elm->obj->path, (void *)fini_addr[index]); 2968 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, 2969 (void *)fini_addr[index], 0, 0, elm->obj->path); 2970 call_initfini_pointer(elm->obj, fini_addr[index]); 2971 } 2972 } 2973 } 2974 if (elm->obj->fini != (Elf_Addr)NULL) { 2975 dbg("calling fini function for %s at %p", elm->obj->path, 2976 (void *)elm->obj->fini); 2977 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, (void *)elm->obj->fini, 2978 0, 0, elm->obj->path); 2979 call_initfini_pointer(elm->obj, elm->obj->fini); 2980 } 2981 wlock_acquire(rtld_bind_lock, lockstate); 2982 unhold_object(elm->obj); 2983 /* No need to free anything if process is going down. */ 2984 if (root != NULL) 2985 free(elm); 2986 /* 2987 * We must restart the list traversal after every fini call 2988 * because a dlclose() call from the fini function or from 2989 * another thread might have modified the reference counts. 2990 */ 2991 break; 2992 } 2993 } while (elm != NULL); 2994 errmsg_restore(saved_msg); 2995 } 2996 2997 /* 2998 * Call the initialization functions for each of the objects in 2999 * "list". All of the objects are expected to have non-NULL init 3000 * functions. 3001 */ 3002 static void 3003 objlist_call_init(Objlist *list, RtldLockState *lockstate) 3004 { 3005 Objlist_Entry *elm; 3006 Obj_Entry *obj; 3007 struct dlerror_save *saved_msg; 3008 Elf_Addr *init_addr; 3009 void (*reg)(void (*)(void)); 3010 int index; 3011 3012 /* 3013 * Clean init_scanned flag so that objects can be rechecked and 3014 * possibly initialized earlier if any of vectors called below 3015 * cause the change by using dlopen. 3016 */ 3017 TAILQ_FOREACH(obj, &obj_list, next) { 3018 if (obj->marker) 3019 continue; 3020 obj->init_scanned = false; 3021 } 3022 3023 /* 3024 * Preserve the current error message since an init function might 3025 * call into the dynamic linker and overwrite it. 3026 */ 3027 saved_msg = errmsg_save(); 3028 STAILQ_FOREACH(elm, list, link) { 3029 if (elm->obj->init_done) /* Initialized early. */ 3030 continue; 3031 /* 3032 * Race: other thread might try to use this object before current 3033 * one completes the initialization. Not much can be done here 3034 * without better locking. 3035 */ 3036 elm->obj->init_done = true; 3037 hold_object(elm->obj); 3038 reg = NULL; 3039 if (elm->obj == obj_main && obj_main->crt_no_init) { 3040 reg = (void (*)(void (*)(void)))get_program_var_addr( 3041 "__libc_atexit", lockstate); 3042 } 3043 lock_release(rtld_bind_lock, lockstate); 3044 if (reg != NULL) { 3045 reg(rtld_exit); 3046 rtld_exit_ptr = rtld_nop_exit; 3047 } 3048 3049 /* 3050 * It is legal to have both DT_INIT and DT_INIT_ARRAY defined. 3051 * When this happens, DT_INIT is processed first. 3052 */ 3053 if (elm->obj->init != (Elf_Addr)NULL) { 3054 dbg("calling init function for %s at %p", elm->obj->path, 3055 (void *)elm->obj->init); 3056 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, (void *)elm->obj->init, 3057 0, 0, elm->obj->path); 3058 call_init_pointer(elm->obj, elm->obj->init); 3059 } 3060 init_addr = (Elf_Addr *)elm->obj->init_array; 3061 if (init_addr != NULL) { 3062 for (index = 0; index < elm->obj->init_array_num; index++) { 3063 if (init_addr[index] != 0 && init_addr[index] != 1) { 3064 dbg("calling init function for %s at %p", elm->obj->path, 3065 (void *)init_addr[index]); 3066 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, 3067 (void *)init_addr[index], 0, 0, elm->obj->path); 3068 call_init_pointer(elm->obj, init_addr[index]); 3069 } 3070 } 3071 } 3072 wlock_acquire(rtld_bind_lock, lockstate); 3073 unhold_object(elm->obj); 3074 } 3075 errmsg_restore(saved_msg); 3076 } 3077 3078 static void 3079 objlist_clear(Objlist *list) 3080 { 3081 Objlist_Entry *elm; 3082 3083 while (!STAILQ_EMPTY(list)) { 3084 elm = STAILQ_FIRST(list); 3085 STAILQ_REMOVE_HEAD(list, link); 3086 free(elm); 3087 } 3088 } 3089 3090 static Objlist_Entry * 3091 objlist_find(Objlist *list, const Obj_Entry *obj) 3092 { 3093 Objlist_Entry *elm; 3094 3095 STAILQ_FOREACH(elm, list, link) 3096 if (elm->obj == obj) 3097 return elm; 3098 return (NULL); 3099 } 3100 3101 static void 3102 objlist_init(Objlist *list) 3103 { 3104 STAILQ_INIT(list); 3105 } 3106 3107 static void 3108 objlist_push_head(Objlist *list, Obj_Entry *obj) 3109 { 3110 Objlist_Entry *elm; 3111 3112 elm = NEW(Objlist_Entry); 3113 elm->obj = obj; 3114 STAILQ_INSERT_HEAD(list, elm, link); 3115 } 3116 3117 static void 3118 objlist_push_tail(Objlist *list, Obj_Entry *obj) 3119 { 3120 Objlist_Entry *elm; 3121 3122 elm = NEW(Objlist_Entry); 3123 elm->obj = obj; 3124 STAILQ_INSERT_TAIL(list, elm, link); 3125 } 3126 3127 static void 3128 objlist_put_after(Objlist *list, Obj_Entry *listobj, Obj_Entry *obj) 3129 { 3130 Objlist_Entry *elm, *listelm; 3131 3132 STAILQ_FOREACH(listelm, list, link) { 3133 if (listelm->obj == listobj) 3134 break; 3135 } 3136 elm = NEW(Objlist_Entry); 3137 elm->obj = obj; 3138 if (listelm != NULL) 3139 STAILQ_INSERT_AFTER(list, listelm, elm, link); 3140 else 3141 STAILQ_INSERT_TAIL(list, elm, link); 3142 } 3143 3144 static void 3145 objlist_remove(Objlist *list, Obj_Entry *obj) 3146 { 3147 Objlist_Entry *elm; 3148 3149 if ((elm = objlist_find(list, obj)) != NULL) { 3150 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 3151 free(elm); 3152 } 3153 } 3154 3155 /* 3156 * Relocate dag rooted in the specified object. 3157 * Returns 0 on success, or -1 on failure. 3158 */ 3159 3160 static int 3161 relocate_object_dag(Obj_Entry *root, bool bind_now, Obj_Entry *rtldobj, 3162 int flags, RtldLockState *lockstate) 3163 { 3164 Objlist_Entry *elm; 3165 int error; 3166 3167 error = 0; 3168 STAILQ_FOREACH(elm, &root->dagmembers, link) { 3169 error = relocate_object(elm->obj, bind_now, rtldobj, flags, 3170 lockstate); 3171 if (error == -1) 3172 break; 3173 } 3174 return (error); 3175 } 3176 3177 /* 3178 * Prepare for, or clean after, relocating an object marked with 3179 * DT_TEXTREL or DF_TEXTREL. Before relocating, all read-only 3180 * segments are remapped read-write. After relocations are done, the 3181 * segment's permissions are returned back to the modes specified in 3182 * the phdrs. If any relocation happened, or always for wired 3183 * program, COW is triggered. 3184 */ 3185 static int 3186 reloc_textrel_prot(Obj_Entry *obj, bool before) 3187 { 3188 const Elf_Phdr *ph; 3189 void *base; 3190 size_t l, sz; 3191 int prot; 3192 3193 for (l = obj->phsize / sizeof(*ph), ph = obj->phdr; l > 0; 3194 l--, ph++) { 3195 if (ph->p_type != PT_LOAD || (ph->p_flags & PF_W) != 0) 3196 continue; 3197 base = obj->relocbase + trunc_page(ph->p_vaddr); 3198 sz = round_page(ph->p_vaddr + ph->p_filesz) - 3199 trunc_page(ph->p_vaddr); 3200 prot = before ? (PROT_READ | PROT_WRITE) : 3201 convert_prot(ph->p_flags); 3202 if (mprotect(base, sz, prot) == -1) { 3203 _rtld_error("%s: Cannot write-%sable text segment: %s", 3204 obj->path, before ? "en" : "dis", 3205 rtld_strerror(errno)); 3206 return (-1); 3207 } 3208 } 3209 return (0); 3210 } 3211 3212 /* Process RELR relative relocations. */ 3213 static void 3214 reloc_relr(Obj_Entry *obj) 3215 { 3216 const Elf_Relr *relr, *relrlim; 3217 Elf_Addr *where; 3218 3219 relrlim = (const Elf_Relr *)((const char *)obj->relr + obj->relrsize); 3220 for (relr = obj->relr; relr < relrlim; relr++) { 3221 Elf_Relr entry = *relr; 3222 3223 if ((entry & 1) == 0) { 3224 where = (Elf_Addr *)(obj->relocbase + entry); 3225 *where++ += (Elf_Addr)obj->relocbase; 3226 } else { 3227 for (long i = 0; (entry >>= 1) != 0; i++) 3228 if ((entry & 1) != 0) 3229 where[i] += (Elf_Addr)obj->relocbase; 3230 where += CHAR_BIT * sizeof(Elf_Relr) - 1; 3231 } 3232 } 3233 } 3234 3235 /* 3236 * Relocate single object. 3237 * Returns 0 on success, or -1 on failure. 3238 */ 3239 static int 3240 relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, 3241 int flags, RtldLockState *lockstate) 3242 { 3243 3244 if (obj->relocated) 3245 return (0); 3246 obj->relocated = true; 3247 if (obj != rtldobj) 3248 dbg("relocating \"%s\"", obj->path); 3249 3250 if (obj->symtab == NULL || obj->strtab == NULL || 3251 !(obj->valid_hash_sysv || obj->valid_hash_gnu)) 3252 dbg("object %s has no run-time symbol table", obj->path); 3253 3254 /* There are relocations to the write-protected text segment. */ 3255 if (obj->textrel && reloc_textrel_prot(obj, true) != 0) 3256 return (-1); 3257 3258 /* Process the non-PLT non-IFUNC relocations. */ 3259 if (reloc_non_plt(obj, rtldobj, flags, lockstate)) 3260 return (-1); 3261 reloc_relr(obj); 3262 3263 /* Re-protected the text segment. */ 3264 if (obj->textrel && reloc_textrel_prot(obj, false) != 0) 3265 return (-1); 3266 3267 /* Set the special PLT or GOT entries. */ 3268 init_pltgot(obj); 3269 3270 /* Process the PLT relocations. */ 3271 if (reloc_plt(obj, flags, lockstate) == -1) 3272 return (-1); 3273 /* Relocate the jump slots if we are doing immediate binding. */ 3274 if ((obj->bind_now || bind_now) && reloc_jmpslots(obj, flags, 3275 lockstate) == -1) 3276 return (-1); 3277 3278 if (!obj->mainprog && obj_enforce_relro(obj) == -1) 3279 return (-1); 3280 3281 /* 3282 * Set up the magic number and version in the Obj_Entry. These 3283 * were checked in the crt1.o from the original ElfKit, so we 3284 * set them for backward compatibility. 3285 */ 3286 obj->magic = RTLD_MAGIC; 3287 obj->version = RTLD_VERSION; 3288 3289 return (0); 3290 } 3291 3292 /* 3293 * Relocate newly-loaded shared objects. The argument is a pointer to 3294 * the Obj_Entry for the first such object. All objects from the first 3295 * to the end of the list of objects are relocated. Returns 0 on success, 3296 * or -1 on failure. 3297 */ 3298 static int 3299 relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj, 3300 int flags, RtldLockState *lockstate) 3301 { 3302 Obj_Entry *obj; 3303 int error; 3304 3305 for (error = 0, obj = first; obj != NULL; 3306 obj = TAILQ_NEXT(obj, next)) { 3307 if (obj->marker) 3308 continue; 3309 error = relocate_object(obj, bind_now, rtldobj, flags, 3310 lockstate); 3311 if (error == -1) 3312 break; 3313 } 3314 return (error); 3315 } 3316 3317 /* 3318 * The handling of R_MACHINE_IRELATIVE relocations and jumpslots 3319 * referencing STT_GNU_IFUNC symbols is postponed till the other 3320 * relocations are done. The indirect functions specified as 3321 * ifunc are allowed to call other symbols, so we need to have 3322 * objects relocated before asking for resolution from indirects. 3323 * 3324 * The R_MACHINE_IRELATIVE slots are resolved in greedy fashion, 3325 * instead of the usual lazy handling of PLT slots. It is 3326 * consistent with how GNU does it. 3327 */ 3328 static int 3329 resolve_object_ifunc(Obj_Entry *obj, bool bind_now, int flags, 3330 RtldLockState *lockstate) 3331 { 3332 3333 if (obj->ifuncs_resolved) 3334 return (0); 3335 obj->ifuncs_resolved = true; 3336 if (!obj->irelative && !obj->irelative_nonplt && 3337 !((obj->bind_now || bind_now) && obj->gnu_ifunc) && 3338 !obj->non_plt_gnu_ifunc) 3339 return (0); 3340 if (obj_disable_relro(obj) == -1 || 3341 (obj->irelative && reloc_iresolve(obj, lockstate) == -1) || 3342 (obj->irelative_nonplt && reloc_iresolve_nonplt(obj, 3343 lockstate) == -1) || 3344 ((obj->bind_now || bind_now) && obj->gnu_ifunc && 3345 reloc_gnu_ifunc(obj, flags, lockstate) == -1) || 3346 (obj->non_plt_gnu_ifunc && reloc_non_plt(obj, &obj_rtld, 3347 flags | SYMLOOK_IFUNC, lockstate) == -1) || 3348 obj_enforce_relro(obj) == -1) 3349 return (-1); 3350 return (0); 3351 } 3352 3353 static int 3354 initlist_objects_ifunc(Objlist *list, bool bind_now, int flags, 3355 RtldLockState *lockstate) 3356 { 3357 Objlist_Entry *elm; 3358 Obj_Entry *obj; 3359 3360 STAILQ_FOREACH(elm, list, link) { 3361 obj = elm->obj; 3362 if (obj->marker) 3363 continue; 3364 if (resolve_object_ifunc(obj, bind_now, flags, 3365 lockstate) == -1) 3366 return (-1); 3367 } 3368 return (0); 3369 } 3370 3371 /* 3372 * Cleanup procedure. It will be called (by the atexit mechanism) just 3373 * before the process exits. 3374 */ 3375 static void 3376 rtld_exit(void) 3377 { 3378 RtldLockState lockstate; 3379 3380 wlock_acquire(rtld_bind_lock, &lockstate); 3381 dbg("rtld_exit()"); 3382 objlist_call_fini(&list_fini, NULL, &lockstate); 3383 /* No need to remove the items from the list, since we are exiting. */ 3384 if (!libmap_disable) 3385 lm_fini(); 3386 lock_release(rtld_bind_lock, &lockstate); 3387 } 3388 3389 static void 3390 rtld_nop_exit(void) 3391 { 3392 } 3393 3394 /* 3395 * Iterate over a search path, translate each element, and invoke the 3396 * callback on the result. 3397 */ 3398 static void * 3399 path_enumerate(const char *path, path_enum_proc callback, 3400 const char *refobj_path, void *arg) 3401 { 3402 const char *trans; 3403 if (path == NULL) 3404 return (NULL); 3405 3406 path += strspn(path, ":;"); 3407 while (*path != '\0') { 3408 size_t len; 3409 char *res; 3410 3411 len = strcspn(path, ":;"); 3412 trans = lm_findn(refobj_path, path, len); 3413 if (trans) 3414 res = callback(trans, strlen(trans), arg); 3415 else 3416 res = callback(path, len, arg); 3417 3418 if (res != NULL) 3419 return (res); 3420 3421 path += len; 3422 path += strspn(path, ":;"); 3423 } 3424 3425 return (NULL); 3426 } 3427 3428 struct try_library_args { 3429 const char *name; 3430 size_t namelen; 3431 char *buffer; 3432 size_t buflen; 3433 int fd; 3434 }; 3435 3436 static void * 3437 try_library_path(const char *dir, size_t dirlen, void *param) 3438 { 3439 struct try_library_args *arg; 3440 int fd; 3441 3442 arg = param; 3443 if (*dir == '/' || trust) { 3444 char *pathname; 3445 3446 if (dirlen + 1 + arg->namelen + 1 > arg->buflen) 3447 return (NULL); 3448 3449 pathname = arg->buffer; 3450 strncpy(pathname, dir, dirlen); 3451 pathname[dirlen] = '/'; 3452 strcpy(pathname + dirlen + 1, arg->name); 3453 3454 dbg(" Trying \"%s\"", pathname); 3455 fd = open(pathname, O_RDONLY | O_CLOEXEC | O_VERIFY); 3456 if (fd >= 0) { 3457 dbg(" Opened \"%s\", fd %d", pathname, fd); 3458 pathname = xmalloc(dirlen + 1 + arg->namelen + 1); 3459 strcpy(pathname, arg->buffer); 3460 arg->fd = fd; 3461 return (pathname); 3462 } else { 3463 dbg(" Failed to open \"%s\": %s", 3464 pathname, rtld_strerror(errno)); 3465 } 3466 } 3467 return (NULL); 3468 } 3469 3470 static char * 3471 search_library_path(const char *name, const char *path, 3472 const char *refobj_path, int *fdp) 3473 { 3474 char *p; 3475 struct try_library_args arg; 3476 3477 if (path == NULL) 3478 return (NULL); 3479 3480 arg.name = name; 3481 arg.namelen = strlen(name); 3482 arg.buffer = xmalloc(PATH_MAX); 3483 arg.buflen = PATH_MAX; 3484 arg.fd = -1; 3485 3486 p = path_enumerate(path, try_library_path, refobj_path, &arg); 3487 *fdp = arg.fd; 3488 3489 free(arg.buffer); 3490 3491 return (p); 3492 } 3493 3494 3495 /* 3496 * Finds the library with the given name using the directory descriptors 3497 * listed in the LD_LIBRARY_PATH_FDS environment variable. 3498 * 3499 * Returns a freshly-opened close-on-exec file descriptor for the library, 3500 * or -1 if the library cannot be found. 3501 */ 3502 static char * 3503 search_library_pathfds(const char *name, const char *path, int *fdp) 3504 { 3505 char *envcopy, *fdstr, *found, *last_token; 3506 size_t len; 3507 int dirfd, fd; 3508 3509 dbg("%s('%s', '%s', fdp)", __func__, name, path); 3510 3511 /* Don't load from user-specified libdirs into setuid binaries. */ 3512 if (!trust) 3513 return (NULL); 3514 3515 /* We can't do anything if LD_LIBRARY_PATH_FDS isn't set. */ 3516 if (path == NULL) 3517 return (NULL); 3518 3519 /* LD_LIBRARY_PATH_FDS only works with relative paths. */ 3520 if (name[0] == '/') { 3521 dbg("Absolute path (%s) passed to %s", name, __func__); 3522 return (NULL); 3523 } 3524 3525 /* 3526 * Use strtok_r() to walk the FD:FD:FD list. This requires a local 3527 * copy of the path, as strtok_r rewrites separator tokens 3528 * with '\0'. 3529 */ 3530 found = NULL; 3531 envcopy = xstrdup(path); 3532 for (fdstr = strtok_r(envcopy, ":", &last_token); fdstr != NULL; 3533 fdstr = strtok_r(NULL, ":", &last_token)) { 3534 dirfd = parse_integer(fdstr); 3535 if (dirfd < 0) { 3536 _rtld_error("failed to parse directory FD: '%s'", 3537 fdstr); 3538 break; 3539 } 3540 fd = __sys_openat(dirfd, name, O_RDONLY | O_CLOEXEC | O_VERIFY); 3541 if (fd >= 0) { 3542 *fdp = fd; 3543 len = strlen(fdstr) + strlen(name) + 3; 3544 found = xmalloc(len); 3545 if (rtld_snprintf(found, len, "#%d/%s", dirfd, name) < 0) { 3546 _rtld_error("error generating '%d/%s'", 3547 dirfd, name); 3548 rtld_die(); 3549 } 3550 dbg("open('%s') => %d", found, fd); 3551 break; 3552 } 3553 } 3554 free(envcopy); 3555 3556 return (found); 3557 } 3558 3559 3560 int 3561 dlclose(void *handle) 3562 { 3563 RtldLockState lockstate; 3564 int error; 3565 3566 wlock_acquire(rtld_bind_lock, &lockstate); 3567 error = dlclose_locked(handle, &lockstate); 3568 lock_release(rtld_bind_lock, &lockstate); 3569 return (error); 3570 } 3571 3572 static int 3573 dlclose_locked(void *handle, RtldLockState *lockstate) 3574 { 3575 Obj_Entry *root; 3576 3577 root = dlcheck(handle); 3578 if (root == NULL) 3579 return (-1); 3580 LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount, 3581 root->path); 3582 3583 /* Unreference the object and its dependencies. */ 3584 root->dl_refcount--; 3585 3586 if (root->refcount == 1) { 3587 /* 3588 * The object will be no longer referenced, so we must unload it. 3589 * First, call the fini functions. 3590 */ 3591 objlist_call_fini(&list_fini, root, lockstate); 3592 3593 unref_dag(root); 3594 3595 /* Finish cleaning up the newly-unreferenced objects. */ 3596 GDB_STATE(RT_DELETE,&root->linkmap); 3597 unload_object(root, lockstate); 3598 GDB_STATE(RT_CONSISTENT,NULL); 3599 } else 3600 unref_dag(root); 3601 3602 LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL); 3603 return (0); 3604 } 3605 3606 char * 3607 dlerror(void) 3608 { 3609 if (*(lockinfo.dlerror_seen()) != 0) 3610 return (NULL); 3611 *lockinfo.dlerror_seen() = 1; 3612 return (lockinfo.dlerror_loc()); 3613 } 3614 3615 /* 3616 * This function is deprecated and has no effect. 3617 */ 3618 void 3619 dllockinit(void *context, 3620 void *(*_lock_create)(void *context) __unused, 3621 void (*_rlock_acquire)(void *lock) __unused, 3622 void (*_wlock_acquire)(void *lock) __unused, 3623 void (*_lock_release)(void *lock) __unused, 3624 void (*_lock_destroy)(void *lock) __unused, 3625 void (*context_destroy)(void *context)) 3626 { 3627 static void *cur_context; 3628 static void (*cur_context_destroy)(void *); 3629 3630 /* Just destroy the context from the previous call, if necessary. */ 3631 if (cur_context_destroy != NULL) 3632 cur_context_destroy(cur_context); 3633 cur_context = context; 3634 cur_context_destroy = context_destroy; 3635 } 3636 3637 void * 3638 dlopen(const char *name, int mode) 3639 { 3640 3641 return (rtld_dlopen(name, -1, mode)); 3642 } 3643 3644 void * 3645 fdlopen(int fd, int mode) 3646 { 3647 3648 return (rtld_dlopen(NULL, fd, mode)); 3649 } 3650 3651 static void * 3652 rtld_dlopen(const char *name, int fd, int mode) 3653 { 3654 RtldLockState lockstate; 3655 int lo_flags; 3656 3657 LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name); 3658 ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1"; 3659 if (ld_tracing != NULL) { 3660 rlock_acquire(rtld_bind_lock, &lockstate); 3661 if (sigsetjmp(lockstate.env, 0) != 0) 3662 lock_upgrade(rtld_bind_lock, &lockstate); 3663 environ = __DECONST(char **, *get_program_var_addr("environ", &lockstate)); 3664 lock_release(rtld_bind_lock, &lockstate); 3665 } 3666 lo_flags = RTLD_LO_DLOPEN; 3667 if (mode & RTLD_NODELETE) 3668 lo_flags |= RTLD_LO_NODELETE; 3669 if (mode & RTLD_NOLOAD) 3670 lo_flags |= RTLD_LO_NOLOAD; 3671 if (mode & RTLD_DEEPBIND) 3672 lo_flags |= RTLD_LO_DEEPBIND; 3673 if (ld_tracing != NULL) 3674 lo_flags |= RTLD_LO_TRACE | RTLD_LO_IGNSTLS; 3675 3676 return (dlopen_object(name, fd, obj_main, lo_flags, 3677 mode & (RTLD_MODEMASK | RTLD_GLOBAL), NULL)); 3678 } 3679 3680 static void 3681 dlopen_cleanup(Obj_Entry *obj, RtldLockState *lockstate) 3682 { 3683 3684 obj->dl_refcount--; 3685 unref_dag(obj); 3686 if (obj->refcount == 0) 3687 unload_object(obj, lockstate); 3688 } 3689 3690 static Obj_Entry * 3691 dlopen_object(const char *name, int fd, Obj_Entry *refobj, int lo_flags, 3692 int mode, RtldLockState *lockstate) 3693 { 3694 Obj_Entry *old_obj_tail; 3695 Obj_Entry *obj; 3696 Objlist initlist; 3697 RtldLockState mlockstate; 3698 int result; 3699 3700 dbg("dlopen_object name \"%s\" fd %d refobj \"%s\" lo_flags %#x mode %#x", 3701 name != NULL ? name : "<null>", fd, refobj == NULL ? "<null>" : 3702 refobj->path, lo_flags, mode); 3703 objlist_init(&initlist); 3704 3705 if (lockstate == NULL && !(lo_flags & RTLD_LO_EARLY)) { 3706 wlock_acquire(rtld_bind_lock, &mlockstate); 3707 lockstate = &mlockstate; 3708 } 3709 GDB_STATE(RT_ADD,NULL); 3710 3711 old_obj_tail = globallist_curr(TAILQ_LAST(&obj_list, obj_entry_q)); 3712 obj = NULL; 3713 if (name == NULL && fd == -1) { 3714 obj = obj_main; 3715 obj->refcount++; 3716 } else { 3717 obj = load_object(name, fd, refobj, lo_flags); 3718 } 3719 3720 if (obj) { 3721 obj->dl_refcount++; 3722 if (mode & RTLD_GLOBAL && objlist_find(&list_global, obj) == NULL) 3723 objlist_push_tail(&list_global, obj); 3724 if (globallist_next(old_obj_tail) != NULL) { 3725 /* We loaded something new. */ 3726 assert(globallist_next(old_obj_tail) == obj); 3727 if ((lo_flags & RTLD_LO_DEEPBIND) != 0) 3728 obj->symbolic = true; 3729 result = 0; 3730 if ((lo_flags & (RTLD_LO_EARLY | RTLD_LO_IGNSTLS)) == 0 && 3731 obj->static_tls && !allocate_tls_offset(obj)) { 3732 _rtld_error("%s: No space available " 3733 "for static Thread Local Storage", obj->path); 3734 result = -1; 3735 } 3736 if (result != -1) 3737 result = load_needed_objects(obj, lo_flags & (RTLD_LO_DLOPEN | 3738 RTLD_LO_EARLY | RTLD_LO_IGNSTLS | RTLD_LO_TRACE)); 3739 init_dag(obj); 3740 ref_dag(obj); 3741 if (result != -1) 3742 result = rtld_verify_versions(&obj->dagmembers); 3743 if (result != -1 && ld_tracing) 3744 goto trace; 3745 if (result == -1 || relocate_object_dag(obj, 3746 (mode & RTLD_MODEMASK) == RTLD_NOW, &obj_rtld, 3747 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 3748 lockstate) == -1) { 3749 dlopen_cleanup(obj, lockstate); 3750 obj = NULL; 3751 } else if (lo_flags & RTLD_LO_EARLY) { 3752 /* 3753 * Do not call the init functions for early loaded 3754 * filtees. The image is still not initialized enough 3755 * for them to work. 3756 * 3757 * Our object is found by the global object list and 3758 * will be ordered among all init calls done right 3759 * before transferring control to main. 3760 */ 3761 } else { 3762 /* Make list of init functions to call. */ 3763 initlist_add_objects(obj, obj, &initlist); 3764 } 3765 /* 3766 * Process all no_delete or global objects here, given 3767 * them own DAGs to prevent their dependencies from being 3768 * unloaded. This has to be done after we have loaded all 3769 * of the dependencies, so that we do not miss any. 3770 */ 3771 if (obj != NULL) 3772 process_z(obj); 3773 } else { 3774 /* 3775 * Bump the reference counts for objects on this DAG. If 3776 * this is the first dlopen() call for the object that was 3777 * already loaded as a dependency, initialize the dag 3778 * starting at it. 3779 */ 3780 init_dag(obj); 3781 ref_dag(obj); 3782 3783 if ((lo_flags & RTLD_LO_TRACE) != 0) 3784 goto trace; 3785 } 3786 if (obj != NULL && ((lo_flags & RTLD_LO_NODELETE) != 0 || 3787 obj->z_nodelete) && !obj->ref_nodel) { 3788 dbg("obj %s nodelete", obj->path); 3789 ref_dag(obj); 3790 obj->z_nodelete = obj->ref_nodel = true; 3791 } 3792 } 3793 3794 LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0, 3795 name); 3796 GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL); 3797 3798 if ((lo_flags & RTLD_LO_EARLY) == 0) { 3799 map_stacks_exec(lockstate); 3800 if (obj != NULL) 3801 distribute_static_tls(&initlist, lockstate); 3802 } 3803 3804 if (initlist_objects_ifunc(&initlist, (mode & RTLD_MODEMASK) == RTLD_NOW, 3805 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 3806 lockstate) == -1) { 3807 objlist_clear(&initlist); 3808 dlopen_cleanup(obj, lockstate); 3809 if (lockstate == &mlockstate) 3810 lock_release(rtld_bind_lock, lockstate); 3811 return (NULL); 3812 } 3813 3814 if (!(lo_flags & RTLD_LO_EARLY)) { 3815 /* Call the init functions. */ 3816 objlist_call_init(&initlist, lockstate); 3817 } 3818 objlist_clear(&initlist); 3819 if (lockstate == &mlockstate) 3820 lock_release(rtld_bind_lock, lockstate); 3821 return (obj); 3822 trace: 3823 trace_loaded_objects(obj); 3824 if (lockstate == &mlockstate) 3825 lock_release(rtld_bind_lock, lockstate); 3826 exit(0); 3827 } 3828 3829 static void * 3830 do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve, 3831 int flags) 3832 { 3833 DoneList donelist; 3834 const Obj_Entry *obj, *defobj; 3835 const Elf_Sym *def; 3836 SymLook req; 3837 RtldLockState lockstate; 3838 tls_index ti; 3839 void *sym; 3840 int res; 3841 3842 def = NULL; 3843 defobj = NULL; 3844 symlook_init(&req, name); 3845 req.ventry = ve; 3846 req.flags = flags | SYMLOOK_IN_PLT; 3847 req.lockstate = &lockstate; 3848 3849 LD_UTRACE(UTRACE_DLSYM_START, handle, NULL, 0, 0, name); 3850 rlock_acquire(rtld_bind_lock, &lockstate); 3851 if (sigsetjmp(lockstate.env, 0) != 0) 3852 lock_upgrade(rtld_bind_lock, &lockstate); 3853 if (handle == NULL || handle == RTLD_NEXT || 3854 handle == RTLD_DEFAULT || handle == RTLD_SELF) { 3855 3856 if ((obj = obj_from_addr(retaddr)) == NULL) { 3857 _rtld_error("Cannot determine caller's shared object"); 3858 lock_release(rtld_bind_lock, &lockstate); 3859 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 3860 return (NULL); 3861 } 3862 if (handle == NULL) { /* Just the caller's shared object. */ 3863 res = symlook_obj(&req, obj); 3864 if (res == 0) { 3865 def = req.sym_out; 3866 defobj = req.defobj_out; 3867 } 3868 } else if (handle == RTLD_NEXT || /* Objects after caller's */ 3869 handle == RTLD_SELF) { /* ... caller included */ 3870 if (handle == RTLD_NEXT) 3871 obj = globallist_next(obj); 3872 for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 3873 if (obj->marker) 3874 continue; 3875 res = symlook_obj(&req, obj); 3876 if (res == 0) { 3877 if (def == NULL || (ld_dynamic_weak && 3878 ELF_ST_BIND(req.sym_out->st_info) != STB_WEAK)) { 3879 def = req.sym_out; 3880 defobj = req.defobj_out; 3881 if (!ld_dynamic_weak || 3882 ELF_ST_BIND(def->st_info) != STB_WEAK) 3883 break; 3884 } 3885 } 3886 } 3887 /* 3888 * Search the dynamic linker itself, and possibly resolve the 3889 * symbol from there. This is how the application links to 3890 * dynamic linker services such as dlopen. 3891 * Note that we ignore ld_dynamic_weak == false case, 3892 * always overriding weak symbols by rtld definitions. 3893 */ 3894 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 3895 res = symlook_obj(&req, &obj_rtld); 3896 if (res == 0) { 3897 def = req.sym_out; 3898 defobj = req.defobj_out; 3899 } 3900 } 3901 } else { 3902 assert(handle == RTLD_DEFAULT); 3903 res = symlook_default(&req, obj); 3904 if (res == 0) { 3905 defobj = req.defobj_out; 3906 def = req.sym_out; 3907 } 3908 } 3909 } else { 3910 if ((obj = dlcheck(handle)) == NULL) { 3911 lock_release(rtld_bind_lock, &lockstate); 3912 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 3913 return (NULL); 3914 } 3915 3916 donelist_init(&donelist); 3917 if (obj->mainprog) { 3918 /* Handle obtained by dlopen(NULL, ...) implies global scope. */ 3919 res = symlook_global(&req, &donelist); 3920 if (res == 0) { 3921 def = req.sym_out; 3922 defobj = req.defobj_out; 3923 } 3924 /* 3925 * Search the dynamic linker itself, and possibly resolve the 3926 * symbol from there. This is how the application links to 3927 * dynamic linker services such as dlopen. 3928 */ 3929 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 3930 res = symlook_obj(&req, &obj_rtld); 3931 if (res == 0) { 3932 def = req.sym_out; 3933 defobj = req.defobj_out; 3934 } 3935 } 3936 } 3937 else { 3938 /* Search the whole DAG rooted at the given object. */ 3939 res = symlook_list(&req, &obj->dagmembers, &donelist); 3940 if (res == 0) { 3941 def = req.sym_out; 3942 defobj = req.defobj_out; 3943 } 3944 } 3945 } 3946 3947 if (def != NULL) { 3948 lock_release(rtld_bind_lock, &lockstate); 3949 3950 /* 3951 * The value required by the caller is derived from the value 3952 * of the symbol. this is simply the relocated value of the 3953 * symbol. 3954 */ 3955 if (ELF_ST_TYPE(def->st_info) == STT_FUNC) 3956 sym = make_function_pointer(def, defobj); 3957 else if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 3958 sym = rtld_resolve_ifunc(defobj, def); 3959 else if (ELF_ST_TYPE(def->st_info) == STT_TLS) { 3960 ti.ti_module = defobj->tlsindex; 3961 ti.ti_offset = def->st_value; 3962 sym = __tls_get_addr(&ti); 3963 } else 3964 sym = defobj->relocbase + def->st_value; 3965 LD_UTRACE(UTRACE_DLSYM_STOP, handle, sym, 0, 0, name); 3966 return (sym); 3967 } 3968 3969 _rtld_error("Undefined symbol \"%s%s%s\"", name, ve != NULL ? "@" : "", 3970 ve != NULL ? ve->name : ""); 3971 lock_release(rtld_bind_lock, &lockstate); 3972 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 3973 return (NULL); 3974 } 3975 3976 void * 3977 dlsym(void *handle, const char *name) 3978 { 3979 return (do_dlsym(handle, name, __builtin_return_address(0), NULL, 3980 SYMLOOK_DLSYM)); 3981 } 3982 3983 dlfunc_t 3984 dlfunc(void *handle, const char *name) 3985 { 3986 union { 3987 void *d; 3988 dlfunc_t f; 3989 } rv; 3990 3991 rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL, 3992 SYMLOOK_DLSYM); 3993 return (rv.f); 3994 } 3995 3996 void * 3997 dlvsym(void *handle, const char *name, const char *version) 3998 { 3999 Ver_Entry ventry; 4000 4001 ventry.name = version; 4002 ventry.file = NULL; 4003 ventry.hash = elf_hash(version); 4004 ventry.flags= 0; 4005 return (do_dlsym(handle, name, __builtin_return_address(0), &ventry, 4006 SYMLOOK_DLSYM)); 4007 } 4008 4009 int 4010 _rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info) 4011 { 4012 const Obj_Entry *obj; 4013 RtldLockState lockstate; 4014 4015 rlock_acquire(rtld_bind_lock, &lockstate); 4016 obj = obj_from_addr(addr); 4017 if (obj == NULL) { 4018 _rtld_error("No shared object contains address"); 4019 lock_release(rtld_bind_lock, &lockstate); 4020 return (0); 4021 } 4022 rtld_fill_dl_phdr_info(obj, phdr_info); 4023 lock_release(rtld_bind_lock, &lockstate); 4024 return (1); 4025 } 4026 4027 int 4028 dladdr(const void *addr, Dl_info *info) 4029 { 4030 const Obj_Entry *obj; 4031 const Elf_Sym *def; 4032 void *symbol_addr; 4033 unsigned long symoffset; 4034 RtldLockState lockstate; 4035 4036 rlock_acquire(rtld_bind_lock, &lockstate); 4037 obj = obj_from_addr(addr); 4038 if (obj == NULL) { 4039 _rtld_error("No shared object contains address"); 4040 lock_release(rtld_bind_lock, &lockstate); 4041 return (0); 4042 } 4043 info->dli_fname = obj->path; 4044 info->dli_fbase = obj->mapbase; 4045 info->dli_saddr = (void *)0; 4046 info->dli_sname = NULL; 4047 4048 /* 4049 * Walk the symbol list looking for the symbol whose address is 4050 * closest to the address sent in. 4051 */ 4052 for (symoffset = 0; symoffset < obj->dynsymcount; symoffset++) { 4053 def = obj->symtab + symoffset; 4054 4055 /* 4056 * For skip the symbol if st_shndx is either SHN_UNDEF or 4057 * SHN_COMMON. 4058 */ 4059 if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON) 4060 continue; 4061 4062 /* 4063 * If the symbol is greater than the specified address, or if it 4064 * is further away from addr than the current nearest symbol, 4065 * then reject it. 4066 */ 4067 symbol_addr = obj->relocbase + def->st_value; 4068 if (symbol_addr > addr || symbol_addr < info->dli_saddr) 4069 continue; 4070 4071 /* Update our idea of the nearest symbol. */ 4072 info->dli_sname = obj->strtab + def->st_name; 4073 info->dli_saddr = symbol_addr; 4074 4075 /* Exact match? */ 4076 if (info->dli_saddr == addr) 4077 break; 4078 } 4079 lock_release(rtld_bind_lock, &lockstate); 4080 return (1); 4081 } 4082 4083 int 4084 dlinfo(void *handle, int request, void *p) 4085 { 4086 const Obj_Entry *obj; 4087 RtldLockState lockstate; 4088 int error; 4089 4090 rlock_acquire(rtld_bind_lock, &lockstate); 4091 4092 if (handle == NULL || handle == RTLD_SELF) { 4093 void *retaddr; 4094 4095 retaddr = __builtin_return_address(0); /* __GNUC__ only */ 4096 if ((obj = obj_from_addr(retaddr)) == NULL) 4097 _rtld_error("Cannot determine caller's shared object"); 4098 } else 4099 obj = dlcheck(handle); 4100 4101 if (obj == NULL) { 4102 lock_release(rtld_bind_lock, &lockstate); 4103 return (-1); 4104 } 4105 4106 error = 0; 4107 switch (request) { 4108 case RTLD_DI_LINKMAP: 4109 *((struct link_map const **)p) = &obj->linkmap; 4110 break; 4111 case RTLD_DI_ORIGIN: 4112 error = rtld_dirname(obj->path, p); 4113 break; 4114 4115 case RTLD_DI_SERINFOSIZE: 4116 case RTLD_DI_SERINFO: 4117 error = do_search_info(obj, request, (struct dl_serinfo *)p); 4118 break; 4119 4120 default: 4121 _rtld_error("Invalid request %d passed to dlinfo()", request); 4122 error = -1; 4123 } 4124 4125 lock_release(rtld_bind_lock, &lockstate); 4126 4127 return (error); 4128 } 4129 4130 static void 4131 rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info) 4132 { 4133 uintptr_t **dtvp; 4134 4135 phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase; 4136 phdr_info->dlpi_name = obj->path; 4137 phdr_info->dlpi_phdr = obj->phdr; 4138 phdr_info->dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]); 4139 phdr_info->dlpi_tls_modid = obj->tlsindex; 4140 dtvp = &_tcb_get()->tcb_dtv; 4141 phdr_info->dlpi_tls_data = (char *)tls_get_addr_slow(dtvp, 4142 obj->tlsindex, 0, true) + TLS_DTV_OFFSET; 4143 phdr_info->dlpi_adds = obj_loads; 4144 phdr_info->dlpi_subs = obj_loads - obj_count; 4145 } 4146 4147 int 4148 dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param) 4149 { 4150 struct dl_phdr_info phdr_info; 4151 Obj_Entry *obj, marker; 4152 RtldLockState bind_lockstate, phdr_lockstate; 4153 int error; 4154 4155 init_marker(&marker); 4156 error = 0; 4157 4158 wlock_acquire(rtld_phdr_lock, &phdr_lockstate); 4159 wlock_acquire(rtld_bind_lock, &bind_lockstate); 4160 for (obj = globallist_curr(TAILQ_FIRST(&obj_list)); obj != NULL;) { 4161 TAILQ_INSERT_AFTER(&obj_list, obj, &marker, next); 4162 rtld_fill_dl_phdr_info(obj, &phdr_info); 4163 hold_object(obj); 4164 lock_release(rtld_bind_lock, &bind_lockstate); 4165 4166 error = callback(&phdr_info, sizeof phdr_info, param); 4167 4168 wlock_acquire(rtld_bind_lock, &bind_lockstate); 4169 unhold_object(obj); 4170 obj = globallist_next(&marker); 4171 TAILQ_REMOVE(&obj_list, &marker, next); 4172 if (error != 0) { 4173 lock_release(rtld_bind_lock, &bind_lockstate); 4174 lock_release(rtld_phdr_lock, &phdr_lockstate); 4175 return (error); 4176 } 4177 } 4178 4179 if (error == 0) { 4180 rtld_fill_dl_phdr_info(&obj_rtld, &phdr_info); 4181 lock_release(rtld_bind_lock, &bind_lockstate); 4182 error = callback(&phdr_info, sizeof(phdr_info), param); 4183 } 4184 lock_release(rtld_phdr_lock, &phdr_lockstate); 4185 return (error); 4186 } 4187 4188 static void * 4189 fill_search_info(const char *dir, size_t dirlen, void *param) 4190 { 4191 struct fill_search_info_args *arg; 4192 4193 arg = param; 4194 4195 if (arg->request == RTLD_DI_SERINFOSIZE) { 4196 arg->serinfo->dls_cnt ++; 4197 arg->serinfo->dls_size += sizeof(struct dl_serpath) + dirlen + 1; 4198 } else { 4199 struct dl_serpath *s_entry; 4200 4201 s_entry = arg->serpath; 4202 s_entry->dls_name = arg->strspace; 4203 s_entry->dls_flags = arg->flags; 4204 4205 strncpy(arg->strspace, dir, dirlen); 4206 arg->strspace[dirlen] = '\0'; 4207 4208 arg->strspace += dirlen + 1; 4209 arg->serpath++; 4210 } 4211 4212 return (NULL); 4213 } 4214 4215 static int 4216 do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info) 4217 { 4218 struct dl_serinfo _info; 4219 struct fill_search_info_args args; 4220 4221 args.request = RTLD_DI_SERINFOSIZE; 4222 args.serinfo = &_info; 4223 4224 _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 4225 _info.dls_cnt = 0; 4226 4227 path_enumerate(obj->rpath, fill_search_info, NULL, &args); 4228 path_enumerate(ld_library_path, fill_search_info, NULL, &args); 4229 path_enumerate(obj->runpath, fill_search_info, NULL, &args); 4230 path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, &args); 4231 if (!obj->z_nodeflib) 4232 path_enumerate(ld_standard_library_path, fill_search_info, NULL, &args); 4233 4234 4235 if (request == RTLD_DI_SERINFOSIZE) { 4236 info->dls_size = _info.dls_size; 4237 info->dls_cnt = _info.dls_cnt; 4238 return (0); 4239 } 4240 4241 if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) { 4242 _rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()"); 4243 return (-1); 4244 } 4245 4246 args.request = RTLD_DI_SERINFO; 4247 args.serinfo = info; 4248 args.serpath = &info->dls_serpath[0]; 4249 args.strspace = (char *)&info->dls_serpath[_info.dls_cnt]; 4250 4251 args.flags = LA_SER_RUNPATH; 4252 if (path_enumerate(obj->rpath, fill_search_info, NULL, &args) != NULL) 4253 return (-1); 4254 4255 args.flags = LA_SER_LIBPATH; 4256 if (path_enumerate(ld_library_path, fill_search_info, NULL, &args) != NULL) 4257 return (-1); 4258 4259 args.flags = LA_SER_RUNPATH; 4260 if (path_enumerate(obj->runpath, fill_search_info, NULL, &args) != NULL) 4261 return (-1); 4262 4263 args.flags = LA_SER_CONFIG; 4264 if (path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, &args) 4265 != NULL) 4266 return (-1); 4267 4268 args.flags = LA_SER_DEFAULT; 4269 if (!obj->z_nodeflib && path_enumerate(ld_standard_library_path, 4270 fill_search_info, NULL, &args) != NULL) 4271 return (-1); 4272 return (0); 4273 } 4274 4275 static int 4276 rtld_dirname(const char *path, char *bname) 4277 { 4278 const char *endp; 4279 4280 /* Empty or NULL string gets treated as "." */ 4281 if (path == NULL || *path == '\0') { 4282 bname[0] = '.'; 4283 bname[1] = '\0'; 4284 return (0); 4285 } 4286 4287 /* Strip trailing slashes */ 4288 endp = path + strlen(path) - 1; 4289 while (endp > path && *endp == '/') 4290 endp--; 4291 4292 /* Find the start of the dir */ 4293 while (endp > path && *endp != '/') 4294 endp--; 4295 4296 /* Either the dir is "/" or there are no slashes */ 4297 if (endp == path) { 4298 bname[0] = *endp == '/' ? '/' : '.'; 4299 bname[1] = '\0'; 4300 return (0); 4301 } else { 4302 do { 4303 endp--; 4304 } while (endp > path && *endp == '/'); 4305 } 4306 4307 if (endp - path + 2 > PATH_MAX) 4308 { 4309 _rtld_error("Filename is too long: %s", path); 4310 return(-1); 4311 } 4312 4313 strncpy(bname, path, endp - path + 1); 4314 bname[endp - path + 1] = '\0'; 4315 return (0); 4316 } 4317 4318 static int 4319 rtld_dirname_abs(const char *path, char *base) 4320 { 4321 char *last; 4322 4323 if (realpath(path, base) == NULL) { 4324 _rtld_error("realpath \"%s\" failed (%s)", path, 4325 rtld_strerror(errno)); 4326 return (-1); 4327 } 4328 dbg("%s -> %s", path, base); 4329 last = strrchr(base, '/'); 4330 if (last == NULL) { 4331 _rtld_error("non-abs result from realpath \"%s\"", path); 4332 return (-1); 4333 } 4334 if (last != base) 4335 *last = '\0'; 4336 return (0); 4337 } 4338 4339 static void 4340 linkmap_add(Obj_Entry *obj) 4341 { 4342 struct link_map *l, *prev; 4343 4344 l = &obj->linkmap; 4345 l->l_name = obj->path; 4346 l->l_base = obj->mapbase; 4347 l->l_ld = obj->dynamic; 4348 l->l_addr = obj->relocbase; 4349 4350 if (r_debug.r_map == NULL) { 4351 r_debug.r_map = l; 4352 return; 4353 } 4354 4355 /* 4356 * Scan to the end of the list, but not past the entry for the 4357 * dynamic linker, which we want to keep at the very end. 4358 */ 4359 for (prev = r_debug.r_map; 4360 prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap; 4361 prev = prev->l_next) 4362 ; 4363 4364 /* Link in the new entry. */ 4365 l->l_prev = prev; 4366 l->l_next = prev->l_next; 4367 if (l->l_next != NULL) 4368 l->l_next->l_prev = l; 4369 prev->l_next = l; 4370 } 4371 4372 static void 4373 linkmap_delete(Obj_Entry *obj) 4374 { 4375 struct link_map *l; 4376 4377 l = &obj->linkmap; 4378 if (l->l_prev == NULL) { 4379 if ((r_debug.r_map = l->l_next) != NULL) 4380 l->l_next->l_prev = NULL; 4381 return; 4382 } 4383 4384 if ((l->l_prev->l_next = l->l_next) != NULL) 4385 l->l_next->l_prev = l->l_prev; 4386 } 4387 4388 /* 4389 * Function for the debugger to set a breakpoint on to gain control. 4390 * 4391 * The two parameters allow the debugger to easily find and determine 4392 * what the runtime loader is doing and to whom it is doing it. 4393 * 4394 * When the loadhook trap is hit (r_debug_state, set at program 4395 * initialization), the arguments can be found on the stack: 4396 * 4397 * +8 struct link_map *m 4398 * +4 struct r_debug *rd 4399 * +0 RetAddr 4400 */ 4401 void 4402 r_debug_state(struct r_debug* rd __unused, struct link_map *m __unused) 4403 { 4404 /* 4405 * The following is a hack to force the compiler to emit calls to 4406 * this function, even when optimizing. If the function is empty, 4407 * the compiler is not obliged to emit any code for calls to it, 4408 * even when marked __noinline. However, gdb depends on those 4409 * calls being made. 4410 */ 4411 __compiler_membar(); 4412 } 4413 4414 /* 4415 * A function called after init routines have completed. This can be used to 4416 * break before a program's entry routine is called, and can be used when 4417 * main is not available in the symbol table. 4418 */ 4419 void 4420 _r_debug_postinit(struct link_map *m __unused) 4421 { 4422 4423 /* See r_debug_state(). */ 4424 __compiler_membar(); 4425 } 4426 4427 static void 4428 release_object(Obj_Entry *obj) 4429 { 4430 4431 if (obj->holdcount > 0) { 4432 obj->unholdfree = true; 4433 return; 4434 } 4435 munmap(obj->mapbase, obj->mapsize); 4436 linkmap_delete(obj); 4437 obj_free(obj); 4438 } 4439 4440 /* 4441 * Get address of the pointer variable in the main program. 4442 * Prefer non-weak symbol over the weak one. 4443 */ 4444 static const void ** 4445 get_program_var_addr(const char *name, RtldLockState *lockstate) 4446 { 4447 SymLook req; 4448 DoneList donelist; 4449 4450 symlook_init(&req, name); 4451 req.lockstate = lockstate; 4452 donelist_init(&donelist); 4453 if (symlook_global(&req, &donelist) != 0) 4454 return (NULL); 4455 if (ELF_ST_TYPE(req.sym_out->st_info) == STT_FUNC) 4456 return ((const void **)make_function_pointer(req.sym_out, 4457 req.defobj_out)); 4458 else if (ELF_ST_TYPE(req.sym_out->st_info) == STT_GNU_IFUNC) 4459 return ((const void **)rtld_resolve_ifunc(req.defobj_out, req.sym_out)); 4460 else 4461 return ((const void **)(req.defobj_out->relocbase + 4462 req.sym_out->st_value)); 4463 } 4464 4465 /* 4466 * Set a pointer variable in the main program to the given value. This 4467 * is used to set key variables such as "environ" before any of the 4468 * init functions are called. 4469 */ 4470 static void 4471 set_program_var(const char *name, const void *value) 4472 { 4473 const void **addr; 4474 4475 if ((addr = get_program_var_addr(name, NULL)) != NULL) { 4476 dbg("\"%s\": *%p <-- %p", name, addr, value); 4477 *addr = value; 4478 } 4479 } 4480 4481 /* 4482 * Search the global objects, including dependencies and main object, 4483 * for the given symbol. 4484 */ 4485 static int 4486 symlook_global(SymLook *req, DoneList *donelist) 4487 { 4488 SymLook req1; 4489 const Objlist_Entry *elm; 4490 int res; 4491 4492 symlook_init_from_req(&req1, req); 4493 4494 /* Search all objects loaded at program start up. */ 4495 if (req->defobj_out == NULL || (ld_dynamic_weak && 4496 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK)) { 4497 res = symlook_list(&req1, &list_main, donelist); 4498 if (res == 0 && (!ld_dynamic_weak || req->defobj_out == NULL || 4499 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4500 req->sym_out = req1.sym_out; 4501 req->defobj_out = req1.defobj_out; 4502 assert(req->defobj_out != NULL); 4503 } 4504 } 4505 4506 /* Search all DAGs whose roots are RTLD_GLOBAL objects. */ 4507 STAILQ_FOREACH(elm, &list_global, link) { 4508 if (req->defobj_out != NULL && (!ld_dynamic_weak || 4509 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK)) 4510 break; 4511 res = symlook_list(&req1, &elm->obj->dagmembers, donelist); 4512 if (res == 0 && (req->defobj_out == NULL || 4513 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4514 req->sym_out = req1.sym_out; 4515 req->defobj_out = req1.defobj_out; 4516 assert(req->defobj_out != NULL); 4517 } 4518 } 4519 4520 return (req->sym_out != NULL ? 0 : ESRCH); 4521 } 4522 4523 /* 4524 * Given a symbol name in a referencing object, find the corresponding 4525 * definition of the symbol. Returns a pointer to the symbol, or NULL if 4526 * no definition was found. Returns a pointer to the Obj_Entry of the 4527 * defining object via the reference parameter DEFOBJ_OUT. 4528 */ 4529 static int 4530 symlook_default(SymLook *req, const Obj_Entry *refobj) 4531 { 4532 DoneList donelist; 4533 const Objlist_Entry *elm; 4534 SymLook req1; 4535 int res; 4536 4537 donelist_init(&donelist); 4538 symlook_init_from_req(&req1, req); 4539 4540 /* 4541 * Look first in the referencing object if linked symbolically, 4542 * and similarly handle protected symbols. 4543 */ 4544 res = symlook_obj(&req1, refobj); 4545 if (res == 0 && (refobj->symbolic || 4546 ELF_ST_VISIBILITY(req1.sym_out->st_other) == STV_PROTECTED)) { 4547 req->sym_out = req1.sym_out; 4548 req->defobj_out = req1.defobj_out; 4549 assert(req->defobj_out != NULL); 4550 } 4551 if (refobj->symbolic || req->defobj_out != NULL) 4552 donelist_check(&donelist, refobj); 4553 4554 symlook_global(req, &donelist); 4555 4556 /* Search all dlopened DAGs containing the referencing object. */ 4557 STAILQ_FOREACH(elm, &refobj->dldags, link) { 4558 if (req->sym_out != NULL && (!ld_dynamic_weak || 4559 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK)) 4560 break; 4561 res = symlook_list(&req1, &elm->obj->dagmembers, &donelist); 4562 if (res == 0 && (req->sym_out == NULL || 4563 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4564 req->sym_out = req1.sym_out; 4565 req->defobj_out = req1.defobj_out; 4566 assert(req->defobj_out != NULL); 4567 } 4568 } 4569 4570 /* 4571 * Search the dynamic linker itself, and possibly resolve the 4572 * symbol from there. This is how the application links to 4573 * dynamic linker services such as dlopen. 4574 */ 4575 if (req->sym_out == NULL || 4576 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 4577 res = symlook_obj(&req1, &obj_rtld); 4578 if (res == 0) { 4579 req->sym_out = req1.sym_out; 4580 req->defobj_out = req1.defobj_out; 4581 assert(req->defobj_out != NULL); 4582 } 4583 } 4584 4585 return (req->sym_out != NULL ? 0 : ESRCH); 4586 } 4587 4588 static int 4589 symlook_list(SymLook *req, const Objlist *objlist, DoneList *dlp) 4590 { 4591 const Elf_Sym *def; 4592 const Obj_Entry *defobj; 4593 const Objlist_Entry *elm; 4594 SymLook req1; 4595 int res; 4596 4597 def = NULL; 4598 defobj = NULL; 4599 STAILQ_FOREACH(elm, objlist, link) { 4600 if (donelist_check(dlp, elm->obj)) 4601 continue; 4602 symlook_init_from_req(&req1, req); 4603 if ((res = symlook_obj(&req1, elm->obj)) == 0) { 4604 if (def == NULL || (ld_dynamic_weak && 4605 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4606 def = req1.sym_out; 4607 defobj = req1.defobj_out; 4608 if (!ld_dynamic_weak || ELF_ST_BIND(def->st_info) != STB_WEAK) 4609 break; 4610 } 4611 } 4612 } 4613 if (def != NULL) { 4614 req->sym_out = def; 4615 req->defobj_out = defobj; 4616 return (0); 4617 } 4618 return (ESRCH); 4619 } 4620 4621 /* 4622 * Search the chain of DAGS cointed to by the given Needed_Entry 4623 * for a symbol of the given name. Each DAG is scanned completely 4624 * before advancing to the next one. Returns a pointer to the symbol, 4625 * or NULL if no definition was found. 4626 */ 4627 static int 4628 symlook_needed(SymLook *req, const Needed_Entry *needed, DoneList *dlp) 4629 { 4630 const Elf_Sym *def; 4631 const Needed_Entry *n; 4632 const Obj_Entry *defobj; 4633 SymLook req1; 4634 int res; 4635 4636 def = NULL; 4637 defobj = NULL; 4638 symlook_init_from_req(&req1, req); 4639 for (n = needed; n != NULL; n = n->next) { 4640 if (n->obj == NULL || 4641 (res = symlook_list(&req1, &n->obj->dagmembers, dlp)) != 0) 4642 continue; 4643 if (def == NULL || (ld_dynamic_weak && 4644 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4645 def = req1.sym_out; 4646 defobj = req1.defobj_out; 4647 if (!ld_dynamic_weak || ELF_ST_BIND(def->st_info) != STB_WEAK) 4648 break; 4649 } 4650 } 4651 if (def != NULL) { 4652 req->sym_out = def; 4653 req->defobj_out = defobj; 4654 return (0); 4655 } 4656 return (ESRCH); 4657 } 4658 4659 /* 4660 * Search the symbol table of a single shared object for a symbol of 4661 * the given name and version, if requested. Returns a pointer to the 4662 * symbol, or NULL if no definition was found. If the object is 4663 * filter, return filtered symbol from filtee. 4664 * 4665 * The symbol's hash value is passed in for efficiency reasons; that 4666 * eliminates many recomputations of the hash value. 4667 */ 4668 int 4669 symlook_obj(SymLook *req, const Obj_Entry *obj) 4670 { 4671 DoneList donelist; 4672 SymLook req1; 4673 int flags, res, mres; 4674 4675 /* 4676 * If there is at least one valid hash at this point, we prefer to 4677 * use the faster GNU version if available. 4678 */ 4679 if (obj->valid_hash_gnu) 4680 mres = symlook_obj1_gnu(req, obj); 4681 else if (obj->valid_hash_sysv) 4682 mres = symlook_obj1_sysv(req, obj); 4683 else 4684 return (EINVAL); 4685 4686 if (mres == 0) { 4687 if (obj->needed_filtees != NULL) { 4688 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; 4689 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 4690 donelist_init(&donelist); 4691 symlook_init_from_req(&req1, req); 4692 res = symlook_needed(&req1, obj->needed_filtees, &donelist); 4693 if (res == 0) { 4694 req->sym_out = req1.sym_out; 4695 req->defobj_out = req1.defobj_out; 4696 } 4697 return (res); 4698 } 4699 if (obj->needed_aux_filtees != NULL) { 4700 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; 4701 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 4702 donelist_init(&donelist); 4703 symlook_init_from_req(&req1, req); 4704 res = symlook_needed(&req1, obj->needed_aux_filtees, &donelist); 4705 if (res == 0) { 4706 req->sym_out = req1.sym_out; 4707 req->defobj_out = req1.defobj_out; 4708 return (res); 4709 } 4710 } 4711 } 4712 return (mres); 4713 } 4714 4715 /* Symbol match routine common to both hash functions */ 4716 static bool 4717 matched_symbol(SymLook *req, const Obj_Entry *obj, Sym_Match_Result *result, 4718 const unsigned long symnum) 4719 { 4720 Elf_Versym verndx; 4721 const Elf_Sym *symp; 4722 const char *strp; 4723 4724 symp = obj->symtab + symnum; 4725 strp = obj->strtab + symp->st_name; 4726 4727 switch (ELF_ST_TYPE(symp->st_info)) { 4728 case STT_FUNC: 4729 case STT_NOTYPE: 4730 case STT_OBJECT: 4731 case STT_COMMON: 4732 case STT_GNU_IFUNC: 4733 if (symp->st_value == 0) 4734 return (false); 4735 /* fallthrough */ 4736 case STT_TLS: 4737 if (symp->st_shndx != SHN_UNDEF) 4738 break; 4739 #ifndef __mips__ 4740 else if (((req->flags & SYMLOOK_IN_PLT) == 0) && 4741 (ELF_ST_TYPE(symp->st_info) == STT_FUNC)) 4742 break; 4743 #endif 4744 /* fallthrough */ 4745 default: 4746 return (false); 4747 } 4748 if (req->name[0] != strp[0] || strcmp(req->name, strp) != 0) 4749 return (false); 4750 4751 if (req->ventry == NULL) { 4752 if (obj->versyms != NULL) { 4753 verndx = VER_NDX(obj->versyms[symnum]); 4754 if (verndx > obj->vernum) { 4755 _rtld_error( 4756 "%s: symbol %s references wrong version %d", 4757 obj->path, obj->strtab + symnum, verndx); 4758 return (false); 4759 } 4760 /* 4761 * If we are not called from dlsym (i.e. this 4762 * is a normal relocation from unversioned 4763 * binary), accept the symbol immediately if 4764 * it happens to have first version after this 4765 * shared object became versioned. Otherwise, 4766 * if symbol is versioned and not hidden, 4767 * remember it. If it is the only symbol with 4768 * this name exported by the shared object, it 4769 * will be returned as a match by the calling 4770 * function. If symbol is global (verndx < 2) 4771 * accept it unconditionally. 4772 */ 4773 if ((req->flags & SYMLOOK_DLSYM) == 0 && 4774 verndx == VER_NDX_GIVEN) { 4775 result->sym_out = symp; 4776 return (true); 4777 } 4778 else if (verndx >= VER_NDX_GIVEN) { 4779 if ((obj->versyms[symnum] & VER_NDX_HIDDEN) 4780 == 0) { 4781 if (result->vsymp == NULL) 4782 result->vsymp = symp; 4783 result->vcount++; 4784 } 4785 return (false); 4786 } 4787 } 4788 result->sym_out = symp; 4789 return (true); 4790 } 4791 if (obj->versyms == NULL) { 4792 if (object_match_name(obj, req->ventry->name)) { 4793 _rtld_error("%s: object %s should provide version %s " 4794 "for symbol %s", obj_rtld.path, obj->path, 4795 req->ventry->name, obj->strtab + symnum); 4796 return (false); 4797 } 4798 } else { 4799 verndx = VER_NDX(obj->versyms[symnum]); 4800 if (verndx > obj->vernum) { 4801 _rtld_error("%s: symbol %s references wrong version %d", 4802 obj->path, obj->strtab + symnum, verndx); 4803 return (false); 4804 } 4805 if (obj->vertab[verndx].hash != req->ventry->hash || 4806 strcmp(obj->vertab[verndx].name, req->ventry->name)) { 4807 /* 4808 * Version does not match. Look if this is a 4809 * global symbol and if it is not hidden. If 4810 * global symbol (verndx < 2) is available, 4811 * use it. Do not return symbol if we are 4812 * called by dlvsym, because dlvsym looks for 4813 * a specific version and default one is not 4814 * what dlvsym wants. 4815 */ 4816 if ((req->flags & SYMLOOK_DLSYM) || 4817 (verndx >= VER_NDX_GIVEN) || 4818 (obj->versyms[symnum] & VER_NDX_HIDDEN)) 4819 return (false); 4820 } 4821 } 4822 result->sym_out = symp; 4823 return (true); 4824 } 4825 4826 /* 4827 * Search for symbol using SysV hash function. 4828 * obj->buckets is known not to be NULL at this point; the test for this was 4829 * performed with the obj->valid_hash_sysv assignment. 4830 */ 4831 static int 4832 symlook_obj1_sysv(SymLook *req, const Obj_Entry *obj) 4833 { 4834 unsigned long symnum; 4835 Sym_Match_Result matchres; 4836 4837 matchres.sym_out = NULL; 4838 matchres.vsymp = NULL; 4839 matchres.vcount = 0; 4840 4841 for (symnum = obj->buckets[req->hash % obj->nbuckets]; 4842 symnum != STN_UNDEF; symnum = obj->chains[symnum]) { 4843 if (symnum >= obj->nchains) 4844 return (ESRCH); /* Bad object */ 4845 4846 if (matched_symbol(req, obj, &matchres, symnum)) { 4847 req->sym_out = matchres.sym_out; 4848 req->defobj_out = obj; 4849 return (0); 4850 } 4851 } 4852 if (matchres.vcount == 1) { 4853 req->sym_out = matchres.vsymp; 4854 req->defobj_out = obj; 4855 return (0); 4856 } 4857 return (ESRCH); 4858 } 4859 4860 /* Search for symbol using GNU hash function */ 4861 static int 4862 symlook_obj1_gnu(SymLook *req, const Obj_Entry *obj) 4863 { 4864 Elf_Addr bloom_word; 4865 const Elf32_Word *hashval; 4866 Elf32_Word bucket; 4867 Sym_Match_Result matchres; 4868 unsigned int h1, h2; 4869 unsigned long symnum; 4870 4871 matchres.sym_out = NULL; 4872 matchres.vsymp = NULL; 4873 matchres.vcount = 0; 4874 4875 /* Pick right bitmask word from Bloom filter array */ 4876 bloom_word = obj->bloom_gnu[(req->hash_gnu / __ELF_WORD_SIZE) & 4877 obj->maskwords_bm_gnu]; 4878 4879 /* Calculate modulus word size of gnu hash and its derivative */ 4880 h1 = req->hash_gnu & (__ELF_WORD_SIZE - 1); 4881 h2 = ((req->hash_gnu >> obj->shift2_gnu) & (__ELF_WORD_SIZE - 1)); 4882 4883 /* Filter out the "definitely not in set" queries */ 4884 if (((bloom_word >> h1) & (bloom_word >> h2) & 1) == 0) 4885 return (ESRCH); 4886 4887 /* Locate hash chain and corresponding value element*/ 4888 bucket = obj->buckets_gnu[req->hash_gnu % obj->nbuckets_gnu]; 4889 if (bucket == 0) 4890 return (ESRCH); 4891 hashval = &obj->chain_zero_gnu[bucket]; 4892 do { 4893 if (((*hashval ^ req->hash_gnu) >> 1) == 0) { 4894 symnum = hashval - obj->chain_zero_gnu; 4895 if (matched_symbol(req, obj, &matchres, symnum)) { 4896 req->sym_out = matchres.sym_out; 4897 req->defobj_out = obj; 4898 return (0); 4899 } 4900 } 4901 } while ((*hashval++ & 1) == 0); 4902 if (matchres.vcount == 1) { 4903 req->sym_out = matchres.vsymp; 4904 req->defobj_out = obj; 4905 return (0); 4906 } 4907 return (ESRCH); 4908 } 4909 4910 static void 4911 trace_loaded_objects(Obj_Entry *obj) 4912 { 4913 const char *fmt1, *fmt2, *fmt, *main_local, *list_containers; 4914 int c; 4915 4916 if ((main_local = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_PROGNAME)) == 4917 NULL) 4918 main_local = ""; 4919 4920 if ((fmt1 = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_FMT1)) == NULL) 4921 fmt1 = "\t%o => %p (%x)\n"; 4922 4923 if ((fmt2 = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_FMT2)) == NULL) 4924 fmt2 = "\t%o (%x)\n"; 4925 4926 list_containers = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_ALL); 4927 4928 for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 4929 Needed_Entry *needed; 4930 const char *name, *path; 4931 bool is_lib; 4932 4933 if (obj->marker) 4934 continue; 4935 if (list_containers && obj->needed != NULL) 4936 rtld_printf("%s:\n", obj->path); 4937 for (needed = obj->needed; needed; needed = needed->next) { 4938 if (needed->obj != NULL) { 4939 if (needed->obj->traced && !list_containers) 4940 continue; 4941 needed->obj->traced = true; 4942 path = needed->obj->path; 4943 } else 4944 path = "not found"; 4945 4946 name = obj->strtab + needed->name; 4947 is_lib = strncmp(name, "lib", 3) == 0; /* XXX - bogus */ 4948 4949 fmt = is_lib ? fmt1 : fmt2; 4950 while ((c = *fmt++) != '\0') { 4951 switch (c) { 4952 default: 4953 rtld_putchar(c); 4954 continue; 4955 case '\\': 4956 switch (c = *fmt) { 4957 case '\0': 4958 continue; 4959 case 'n': 4960 rtld_putchar('\n'); 4961 break; 4962 case 't': 4963 rtld_putchar('\t'); 4964 break; 4965 } 4966 break; 4967 case '%': 4968 switch (c = *fmt) { 4969 case '\0': 4970 continue; 4971 case '%': 4972 default: 4973 rtld_putchar(c); 4974 break; 4975 case 'A': 4976 rtld_putstr(main_local); 4977 break; 4978 case 'a': 4979 rtld_putstr(obj_main->path); 4980 break; 4981 case 'o': 4982 rtld_putstr(name); 4983 break; 4984 #if 0 4985 case 'm': 4986 rtld_printf("%d", sodp->sod_major); 4987 break; 4988 case 'n': 4989 rtld_printf("%d", sodp->sod_minor); 4990 break; 4991 #endif 4992 case 'p': 4993 rtld_putstr(path); 4994 break; 4995 case 'x': 4996 rtld_printf("%p", needed->obj ? needed->obj->mapbase : 4997 0); 4998 break; 4999 } 5000 break; 5001 } 5002 ++fmt; 5003 } 5004 } 5005 } 5006 } 5007 5008 /* 5009 * Unload a dlopened object and its dependencies from memory and from 5010 * our data structures. It is assumed that the DAG rooted in the 5011 * object has already been unreferenced, and that the object has a 5012 * reference count of 0. 5013 */ 5014 static void 5015 unload_object(Obj_Entry *root, RtldLockState *lockstate) 5016 { 5017 Obj_Entry marker, *obj, *next; 5018 5019 assert(root->refcount == 0); 5020 5021 /* 5022 * Pass over the DAG removing unreferenced objects from 5023 * appropriate lists. 5024 */ 5025 unlink_object(root); 5026 5027 /* Unmap all objects that are no longer referenced. */ 5028 for (obj = TAILQ_FIRST(&obj_list); obj != NULL; obj = next) { 5029 next = TAILQ_NEXT(obj, next); 5030 if (obj->marker || obj->refcount != 0) 5031 continue; 5032 LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase, 5033 obj->mapsize, 0, obj->path); 5034 dbg("unloading \"%s\"", obj->path); 5035 /* 5036 * Unlink the object now to prevent new references from 5037 * being acquired while the bind lock is dropped in 5038 * recursive dlclose() invocations. 5039 */ 5040 TAILQ_REMOVE(&obj_list, obj, next); 5041 obj_count--; 5042 5043 if (obj->filtees_loaded) { 5044 if (next != NULL) { 5045 init_marker(&marker); 5046 TAILQ_INSERT_BEFORE(next, &marker, next); 5047 unload_filtees(obj, lockstate); 5048 next = TAILQ_NEXT(&marker, next); 5049 TAILQ_REMOVE(&obj_list, &marker, next); 5050 } else 5051 unload_filtees(obj, lockstate); 5052 } 5053 release_object(obj); 5054 } 5055 } 5056 5057 static void 5058 unlink_object(Obj_Entry *root) 5059 { 5060 Objlist_Entry *elm; 5061 5062 if (root->refcount == 0) { 5063 /* Remove the object from the RTLD_GLOBAL list. */ 5064 objlist_remove(&list_global, root); 5065 5066 /* Remove the object from all objects' DAG lists. */ 5067 STAILQ_FOREACH(elm, &root->dagmembers, link) { 5068 objlist_remove(&elm->obj->dldags, root); 5069 if (elm->obj != root) 5070 unlink_object(elm->obj); 5071 } 5072 } 5073 } 5074 5075 static void 5076 ref_dag(Obj_Entry *root) 5077 { 5078 Objlist_Entry *elm; 5079 5080 assert(root->dag_inited); 5081 STAILQ_FOREACH(elm, &root->dagmembers, link) 5082 elm->obj->refcount++; 5083 } 5084 5085 static void 5086 unref_dag(Obj_Entry *root) 5087 { 5088 Objlist_Entry *elm; 5089 5090 assert(root->dag_inited); 5091 STAILQ_FOREACH(elm, &root->dagmembers, link) 5092 elm->obj->refcount--; 5093 } 5094 5095 /* 5096 * Common code for MD __tls_get_addr(). 5097 */ 5098 static void * 5099 tls_get_addr_slow(Elf_Addr **dtvp, int index, size_t offset, bool locked) 5100 { 5101 Elf_Addr *newdtv, *dtv; 5102 RtldLockState lockstate; 5103 int to_copy; 5104 5105 dtv = *dtvp; 5106 /* Check dtv generation in case new modules have arrived */ 5107 if (dtv[0] != tls_dtv_generation) { 5108 if (!locked) 5109 wlock_acquire(rtld_bind_lock, &lockstate); 5110 newdtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 5111 to_copy = dtv[1]; 5112 if (to_copy > tls_max_index) 5113 to_copy = tls_max_index; 5114 memcpy(&newdtv[2], &dtv[2], to_copy * sizeof(Elf_Addr)); 5115 newdtv[0] = tls_dtv_generation; 5116 newdtv[1] = tls_max_index; 5117 free(dtv); 5118 if (!locked) 5119 lock_release(rtld_bind_lock, &lockstate); 5120 dtv = *dtvp = newdtv; 5121 } 5122 5123 /* Dynamically allocate module TLS if necessary */ 5124 if (dtv[index + 1] == 0) { 5125 /* Signal safe, wlock will block out signals. */ 5126 if (!locked) 5127 wlock_acquire(rtld_bind_lock, &lockstate); 5128 if (!dtv[index + 1]) 5129 dtv[index + 1] = (Elf_Addr)allocate_module_tls(index); 5130 if (!locked) 5131 lock_release(rtld_bind_lock, &lockstate); 5132 } 5133 return ((void *)(dtv[index + 1] + offset)); 5134 } 5135 5136 void * 5137 tls_get_addr_common(uintptr_t **dtvp, int index, size_t offset) 5138 { 5139 uintptr_t *dtv; 5140 5141 dtv = *dtvp; 5142 /* Check dtv generation in case new modules have arrived */ 5143 if (__predict_true(dtv[0] == tls_dtv_generation && 5144 dtv[index + 1] != 0)) 5145 return ((void *)(dtv[index + 1] + offset)); 5146 return (tls_get_addr_slow(dtvp, index, offset, false)); 5147 } 5148 5149 #ifdef TLS_VARIANT_I 5150 5151 /* 5152 * Return pointer to allocated TLS block 5153 */ 5154 static void * 5155 get_tls_block_ptr(void *tcb, size_t tcbsize) 5156 { 5157 size_t extra_size, post_size, pre_size, tls_block_size; 5158 size_t tls_init_align; 5159 5160 tls_init_align = MAX(obj_main->tlsalign, 1); 5161 5162 /* Compute fragments sizes. */ 5163 extra_size = tcbsize - TLS_TCB_SIZE; 5164 post_size = calculate_tls_post_size(tls_init_align); 5165 tls_block_size = tcbsize + post_size; 5166 pre_size = roundup2(tls_block_size, tls_init_align) - tls_block_size; 5167 5168 return ((char *)tcb - pre_size - extra_size); 5169 } 5170 5171 /* 5172 * Allocate Static TLS using the Variant I method. 5173 * 5174 * For details on the layout, see lib/libc/gen/tls.c. 5175 * 5176 * NB: rtld's tls_static_space variable includes TLS_TCB_SIZE and post_size as 5177 * it is based on tls_last_offset, and TLS offsets here are really TCB 5178 * offsets, whereas libc's tls_static_space is just the executable's static 5179 * TLS segment. 5180 */ 5181 void * 5182 allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign) 5183 { 5184 Obj_Entry *obj; 5185 char *tls_block; 5186 Elf_Addr *dtv, **tcb; 5187 Elf_Addr addr; 5188 Elf_Addr i; 5189 size_t extra_size, maxalign, post_size, pre_size, tls_block_size; 5190 size_t tls_init_align, tls_init_offset; 5191 5192 if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE) 5193 return (oldtcb); 5194 5195 assert(tcbsize >= TLS_TCB_SIZE); 5196 maxalign = MAX(tcbalign, tls_static_max_align); 5197 tls_init_align = MAX(obj_main->tlsalign, 1); 5198 5199 /* Compute fragmets sizes. */ 5200 extra_size = tcbsize - TLS_TCB_SIZE; 5201 post_size = calculate_tls_post_size(tls_init_align); 5202 tls_block_size = tcbsize + post_size; 5203 pre_size = roundup2(tls_block_size, tls_init_align) - tls_block_size; 5204 tls_block_size += pre_size + tls_static_space - TLS_TCB_SIZE - post_size; 5205 5206 /* Allocate whole TLS block */ 5207 tls_block = malloc_aligned(tls_block_size, maxalign, 0); 5208 tcb = (Elf_Addr **)(tls_block + pre_size + extra_size); 5209 5210 if (oldtcb != NULL) { 5211 memcpy(tls_block, get_tls_block_ptr(oldtcb, tcbsize), 5212 tls_static_space); 5213 free_aligned(get_tls_block_ptr(oldtcb, tcbsize)); 5214 5215 /* Adjust the DTV. */ 5216 dtv = tcb[0]; 5217 for (i = 0; i < dtv[1]; i++) { 5218 if (dtv[i+2] >= (Elf_Addr)oldtcb && 5219 dtv[i+2] < (Elf_Addr)oldtcb + tls_static_space) { 5220 dtv[i+2] = dtv[i+2] - (Elf_Addr)oldtcb + (Elf_Addr)tcb; 5221 } 5222 } 5223 } else { 5224 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 5225 tcb[0] = dtv; 5226 dtv[0] = tls_dtv_generation; 5227 dtv[1] = tls_max_index; 5228 5229 for (obj = globallist_curr(objs); obj != NULL; 5230 obj = globallist_next(obj)) { 5231 if (obj->tlsoffset == 0) 5232 continue; 5233 tls_init_offset = obj->tlspoffset & (obj->tlsalign - 1); 5234 addr = (Elf_Addr)tcb + obj->tlsoffset; 5235 if (tls_init_offset > 0) 5236 memset((void *)addr, 0, tls_init_offset); 5237 if (obj->tlsinitsize > 0) { 5238 memcpy((void *)(addr + tls_init_offset), obj->tlsinit, 5239 obj->tlsinitsize); 5240 } 5241 if (obj->tlssize > obj->tlsinitsize) { 5242 memset((void *)(addr + tls_init_offset + obj->tlsinitsize), 5243 0, obj->tlssize - obj->tlsinitsize - tls_init_offset); 5244 } 5245 dtv[obj->tlsindex + 1] = addr; 5246 } 5247 } 5248 5249 return (tcb); 5250 } 5251 5252 void 5253 free_tls(void *tcb, size_t tcbsize, size_t tcbalign __unused) 5254 { 5255 Elf_Addr *dtv; 5256 Elf_Addr tlsstart, tlsend; 5257 size_t post_size; 5258 size_t dtvsize, i, tls_init_align; 5259 5260 assert(tcbsize >= TLS_TCB_SIZE); 5261 tls_init_align = MAX(obj_main->tlsalign, 1); 5262 5263 /* Compute fragments sizes. */ 5264 post_size = calculate_tls_post_size(tls_init_align); 5265 5266 tlsstart = (Elf_Addr)tcb + TLS_TCB_SIZE + post_size; 5267 tlsend = (Elf_Addr)tcb + tls_static_space; 5268 5269 dtv = *(Elf_Addr **)tcb; 5270 dtvsize = dtv[1]; 5271 for (i = 0; i < dtvsize; i++) { 5272 if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] >= tlsend)) { 5273 free((void*)dtv[i+2]); 5274 } 5275 } 5276 free(dtv); 5277 free_aligned(get_tls_block_ptr(tcb, tcbsize)); 5278 } 5279 5280 #endif /* TLS_VARIANT_I */ 5281 5282 #ifdef TLS_VARIANT_II 5283 5284 /* 5285 * Allocate Static TLS using the Variant II method. 5286 */ 5287 void * 5288 allocate_tls(Obj_Entry *objs, void *oldtls, size_t tcbsize, size_t tcbalign) 5289 { 5290 Obj_Entry *obj; 5291 size_t size, ralign; 5292 char *tls; 5293 Elf_Addr *dtv, *olddtv; 5294 Elf_Addr segbase, oldsegbase, addr; 5295 size_t i; 5296 5297 ralign = tcbalign; 5298 if (tls_static_max_align > ralign) 5299 ralign = tls_static_max_align; 5300 size = roundup(tls_static_space, ralign) + roundup(tcbsize, ralign); 5301 5302 assert(tcbsize >= 2*sizeof(Elf_Addr)); 5303 tls = malloc_aligned(size, ralign, 0 /* XXX */); 5304 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 5305 5306 segbase = (Elf_Addr)(tls + roundup(tls_static_space, ralign)); 5307 ((Elf_Addr *)segbase)[0] = segbase; 5308 ((Elf_Addr *)segbase)[1] = (Elf_Addr) dtv; 5309 5310 dtv[0] = tls_dtv_generation; 5311 dtv[1] = tls_max_index; 5312 5313 if (oldtls) { 5314 /* 5315 * Copy the static TLS block over whole. 5316 */ 5317 oldsegbase = (Elf_Addr) oldtls; 5318 memcpy((void *)(segbase - tls_static_space), 5319 (const void *)(oldsegbase - tls_static_space), 5320 tls_static_space); 5321 5322 /* 5323 * If any dynamic TLS blocks have been created tls_get_addr(), 5324 * move them over. 5325 */ 5326 olddtv = ((Elf_Addr **)oldsegbase)[1]; 5327 for (i = 0; i < olddtv[1]; i++) { 5328 if (olddtv[i + 2] < oldsegbase - size || 5329 olddtv[i + 2] > oldsegbase) { 5330 dtv[i + 2] = olddtv[i + 2]; 5331 olddtv[i + 2] = 0; 5332 } 5333 } 5334 5335 /* 5336 * We assume that this block was the one we created with 5337 * allocate_initial_tls(). 5338 */ 5339 free_tls(oldtls, 2 * sizeof(Elf_Addr), sizeof(Elf_Addr)); 5340 } else { 5341 for (obj = objs; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 5342 if (obj->marker || obj->tlsoffset == 0) 5343 continue; 5344 addr = segbase - obj->tlsoffset; 5345 memset((void *)(addr + obj->tlsinitsize), 5346 0, obj->tlssize - obj->tlsinitsize); 5347 if (obj->tlsinit) { 5348 memcpy((void *)addr, obj->tlsinit, obj->tlsinitsize); 5349 obj->static_tls_copied = true; 5350 } 5351 dtv[obj->tlsindex + 1] = addr; 5352 } 5353 } 5354 5355 return ((void *)segbase); 5356 } 5357 5358 void 5359 free_tls(void *tls, size_t tcbsize __unused, size_t tcbalign) 5360 { 5361 Elf_Addr* dtv; 5362 size_t size, ralign; 5363 int dtvsize, i; 5364 Elf_Addr tlsstart, tlsend; 5365 5366 /* 5367 * Figure out the size of the initial TLS block so that we can 5368 * find stuff which ___tls_get_addr() allocated dynamically. 5369 */ 5370 ralign = tcbalign; 5371 if (tls_static_max_align > ralign) 5372 ralign = tls_static_max_align; 5373 size = roundup(tls_static_space, ralign); 5374 5375 dtv = ((Elf_Addr **)tls)[1]; 5376 dtvsize = dtv[1]; 5377 tlsend = (Elf_Addr)tls; 5378 tlsstart = tlsend - size; 5379 for (i = 0; i < dtvsize; i++) { 5380 if (dtv[i + 2] != 0 && (dtv[i + 2] < tlsstart || 5381 dtv[i + 2] > tlsend)) { 5382 free_aligned((void *)dtv[i + 2]); 5383 } 5384 } 5385 5386 free_aligned((void *)tlsstart); 5387 free((void *)dtv); 5388 } 5389 5390 #endif /* TLS_VARIANT_II */ 5391 5392 /* 5393 * Allocate TLS block for module with given index. 5394 */ 5395 void * 5396 allocate_module_tls(int index) 5397 { 5398 Obj_Entry *obj; 5399 char *p; 5400 5401 TAILQ_FOREACH(obj, &obj_list, next) { 5402 if (obj->marker) 5403 continue; 5404 if (obj->tlsindex == index) 5405 break; 5406 } 5407 if (obj == NULL) { 5408 _rtld_error("Can't find module with TLS index %d", index); 5409 rtld_die(); 5410 } 5411 5412 p = malloc_aligned(obj->tlssize, obj->tlsalign, obj->tlspoffset); 5413 memcpy(p, obj->tlsinit, obj->tlsinitsize); 5414 memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize); 5415 return (p); 5416 } 5417 5418 bool 5419 allocate_tls_offset(Obj_Entry *obj) 5420 { 5421 size_t off; 5422 5423 if (obj->tls_done) 5424 return (true); 5425 5426 if (obj->tlssize == 0) { 5427 obj->tls_done = true; 5428 return (true); 5429 } 5430 5431 if (tls_last_offset == 0) 5432 off = calculate_first_tls_offset(obj->tlssize, obj->tlsalign, 5433 obj->tlspoffset); 5434 else 5435 off = calculate_tls_offset(tls_last_offset, tls_last_size, 5436 obj->tlssize, obj->tlsalign, obj->tlspoffset); 5437 5438 obj->tlsoffset = off; 5439 #ifdef TLS_VARIANT_I 5440 off += obj->tlssize; 5441 #endif 5442 5443 /* 5444 * If we have already fixed the size of the static TLS block, we 5445 * must stay within that size. When allocating the static TLS, we 5446 * leave a small amount of space spare to be used for dynamically 5447 * loading modules which use static TLS. 5448 */ 5449 if (tls_static_space != 0) { 5450 if (off > tls_static_space) 5451 return (false); 5452 } else if (obj->tlsalign > tls_static_max_align) { 5453 tls_static_max_align = obj->tlsalign; 5454 } 5455 5456 tls_last_offset = off; 5457 tls_last_size = obj->tlssize; 5458 obj->tls_done = true; 5459 5460 return (true); 5461 } 5462 5463 void 5464 free_tls_offset(Obj_Entry *obj) 5465 { 5466 5467 /* 5468 * If we were the last thing to allocate out of the static TLS 5469 * block, we give our space back to the 'allocator'. This is a 5470 * simplistic workaround to allow libGL.so.1 to be loaded and 5471 * unloaded multiple times. 5472 */ 5473 size_t off = obj->tlsoffset; 5474 #ifdef TLS_VARIANT_I 5475 off += obj->tlssize; 5476 #endif 5477 if (off == tls_last_offset) { 5478 tls_last_offset -= obj->tlssize; 5479 tls_last_size = 0; 5480 } 5481 } 5482 5483 void * 5484 _rtld_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign) 5485 { 5486 void *ret; 5487 RtldLockState lockstate; 5488 5489 wlock_acquire(rtld_bind_lock, &lockstate); 5490 ret = allocate_tls(globallist_curr(TAILQ_FIRST(&obj_list)), oldtls, 5491 tcbsize, tcbalign); 5492 lock_release(rtld_bind_lock, &lockstate); 5493 return (ret); 5494 } 5495 5496 void 5497 _rtld_free_tls(void *tcb, size_t tcbsize, size_t tcbalign) 5498 { 5499 RtldLockState lockstate; 5500 5501 wlock_acquire(rtld_bind_lock, &lockstate); 5502 free_tls(tcb, tcbsize, tcbalign); 5503 lock_release(rtld_bind_lock, &lockstate); 5504 } 5505 5506 static void 5507 object_add_name(Obj_Entry *obj, const char *name) 5508 { 5509 Name_Entry *entry; 5510 size_t len; 5511 5512 len = strlen(name); 5513 entry = malloc(sizeof(Name_Entry) + len); 5514 5515 if (entry != NULL) { 5516 strcpy(entry->name, name); 5517 STAILQ_INSERT_TAIL(&obj->names, entry, link); 5518 } 5519 } 5520 5521 static int 5522 object_match_name(const Obj_Entry *obj, const char *name) 5523 { 5524 Name_Entry *entry; 5525 5526 STAILQ_FOREACH(entry, &obj->names, link) { 5527 if (strcmp(name, entry->name) == 0) 5528 return (1); 5529 } 5530 return (0); 5531 } 5532 5533 static Obj_Entry * 5534 locate_dependency(const Obj_Entry *obj, const char *name) 5535 { 5536 const Objlist_Entry *entry; 5537 const Needed_Entry *needed; 5538 5539 STAILQ_FOREACH(entry, &list_main, link) { 5540 if (object_match_name(entry->obj, name)) 5541 return (entry->obj); 5542 } 5543 5544 for (needed = obj->needed; needed != NULL; needed = needed->next) { 5545 if (strcmp(obj->strtab + needed->name, name) == 0 || 5546 (needed->obj != NULL && object_match_name(needed->obj, name))) { 5547 /* 5548 * If there is DT_NEEDED for the name we are looking for, 5549 * we are all set. Note that object might not be found if 5550 * dependency was not loaded yet, so the function can 5551 * return NULL here. This is expected and handled 5552 * properly by the caller. 5553 */ 5554 return (needed->obj); 5555 } 5556 } 5557 _rtld_error("%s: Unexpected inconsistency: dependency %s not found", 5558 obj->path, name); 5559 rtld_die(); 5560 } 5561 5562 static int 5563 check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj, 5564 const Elf_Vernaux *vna) 5565 { 5566 const Elf_Verdef *vd; 5567 const char *vername; 5568 5569 vername = refobj->strtab + vna->vna_name; 5570 vd = depobj->verdef; 5571 if (vd == NULL) { 5572 _rtld_error("%s: version %s required by %s not defined", 5573 depobj->path, vername, refobj->path); 5574 return (-1); 5575 } 5576 for (;;) { 5577 if (vd->vd_version != VER_DEF_CURRENT) { 5578 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 5579 depobj->path, vd->vd_version); 5580 return (-1); 5581 } 5582 if (vna->vna_hash == vd->vd_hash) { 5583 const Elf_Verdaux *aux = (const Elf_Verdaux *) 5584 ((const char *)vd + vd->vd_aux); 5585 if (strcmp(vername, depobj->strtab + aux->vda_name) == 0) 5586 return (0); 5587 } 5588 if (vd->vd_next == 0) 5589 break; 5590 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 5591 } 5592 if (vna->vna_flags & VER_FLG_WEAK) 5593 return (0); 5594 _rtld_error("%s: version %s required by %s not found", 5595 depobj->path, vername, refobj->path); 5596 return (-1); 5597 } 5598 5599 static int 5600 rtld_verify_object_versions(Obj_Entry *obj) 5601 { 5602 const Elf_Verneed *vn; 5603 const Elf_Verdef *vd; 5604 const Elf_Verdaux *vda; 5605 const Elf_Vernaux *vna; 5606 const Obj_Entry *depobj; 5607 int maxvernum, vernum; 5608 5609 if (obj->ver_checked) 5610 return (0); 5611 obj->ver_checked = true; 5612 5613 maxvernum = 0; 5614 /* 5615 * Walk over defined and required version records and figure out 5616 * max index used by any of them. Do very basic sanity checking 5617 * while there. 5618 */ 5619 vn = obj->verneed; 5620 while (vn != NULL) { 5621 if (vn->vn_version != VER_NEED_CURRENT) { 5622 _rtld_error("%s: Unsupported version %d of Elf_Verneed entry", 5623 obj->path, vn->vn_version); 5624 return (-1); 5625 } 5626 vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux); 5627 for (;;) { 5628 vernum = VER_NEED_IDX(vna->vna_other); 5629 if (vernum > maxvernum) 5630 maxvernum = vernum; 5631 if (vna->vna_next == 0) 5632 break; 5633 vna = (const Elf_Vernaux *)((const char *)vna + vna->vna_next); 5634 } 5635 if (vn->vn_next == 0) 5636 break; 5637 vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next); 5638 } 5639 5640 vd = obj->verdef; 5641 while (vd != NULL) { 5642 if (vd->vd_version != VER_DEF_CURRENT) { 5643 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 5644 obj->path, vd->vd_version); 5645 return (-1); 5646 } 5647 vernum = VER_DEF_IDX(vd->vd_ndx); 5648 if (vernum > maxvernum) 5649 maxvernum = vernum; 5650 if (vd->vd_next == 0) 5651 break; 5652 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 5653 } 5654 5655 if (maxvernum == 0) 5656 return (0); 5657 5658 /* 5659 * Store version information in array indexable by version index. 5660 * Verify that object version requirements are satisfied along the 5661 * way. 5662 */ 5663 obj->vernum = maxvernum + 1; 5664 obj->vertab = xcalloc(obj->vernum, sizeof(Ver_Entry)); 5665 5666 vd = obj->verdef; 5667 while (vd != NULL) { 5668 if ((vd->vd_flags & VER_FLG_BASE) == 0) { 5669 vernum = VER_DEF_IDX(vd->vd_ndx); 5670 assert(vernum <= maxvernum); 5671 vda = (const Elf_Verdaux *)((const char *)vd + vd->vd_aux); 5672 obj->vertab[vernum].hash = vd->vd_hash; 5673 obj->vertab[vernum].name = obj->strtab + vda->vda_name; 5674 obj->vertab[vernum].file = NULL; 5675 obj->vertab[vernum].flags = 0; 5676 } 5677 if (vd->vd_next == 0) 5678 break; 5679 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 5680 } 5681 5682 vn = obj->verneed; 5683 while (vn != NULL) { 5684 depobj = locate_dependency(obj, obj->strtab + vn->vn_file); 5685 if (depobj == NULL) 5686 return (-1); 5687 vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux); 5688 for (;;) { 5689 if (check_object_provided_version(obj, depobj, vna)) 5690 return (-1); 5691 vernum = VER_NEED_IDX(vna->vna_other); 5692 assert(vernum <= maxvernum); 5693 obj->vertab[vernum].hash = vna->vna_hash; 5694 obj->vertab[vernum].name = obj->strtab + vna->vna_name; 5695 obj->vertab[vernum].file = obj->strtab + vn->vn_file; 5696 obj->vertab[vernum].flags = (vna->vna_other & VER_NEED_HIDDEN) ? 5697 VER_INFO_HIDDEN : 0; 5698 if (vna->vna_next == 0) 5699 break; 5700 vna = (const Elf_Vernaux *)((const char *)vna + vna->vna_next); 5701 } 5702 if (vn->vn_next == 0) 5703 break; 5704 vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next); 5705 } 5706 return (0); 5707 } 5708 5709 static int 5710 rtld_verify_versions(const Objlist *objlist) 5711 { 5712 Objlist_Entry *entry; 5713 int rc; 5714 5715 rc = 0; 5716 STAILQ_FOREACH(entry, objlist, link) { 5717 /* 5718 * Skip dummy objects or objects that have their version requirements 5719 * already checked. 5720 */ 5721 if (entry->obj->strtab == NULL || entry->obj->vertab != NULL) 5722 continue; 5723 if (rtld_verify_object_versions(entry->obj) == -1) { 5724 rc = -1; 5725 if (ld_tracing == NULL) 5726 break; 5727 } 5728 } 5729 if (rc == 0 || ld_tracing != NULL) 5730 rc = rtld_verify_object_versions(&obj_rtld); 5731 return (rc); 5732 } 5733 5734 const Ver_Entry * 5735 fetch_ventry(const Obj_Entry *obj, unsigned long symnum) 5736 { 5737 Elf_Versym vernum; 5738 5739 if (obj->vertab) { 5740 vernum = VER_NDX(obj->versyms[symnum]); 5741 if (vernum >= obj->vernum) { 5742 _rtld_error("%s: symbol %s has wrong verneed value %d", 5743 obj->path, obj->strtab + symnum, vernum); 5744 } else if (obj->vertab[vernum].hash != 0) { 5745 return (&obj->vertab[vernum]); 5746 } 5747 } 5748 return (NULL); 5749 } 5750 5751 int 5752 _rtld_get_stack_prot(void) 5753 { 5754 5755 return (stack_prot); 5756 } 5757 5758 int 5759 _rtld_is_dlopened(void *arg) 5760 { 5761 Obj_Entry *obj; 5762 RtldLockState lockstate; 5763 int res; 5764 5765 rlock_acquire(rtld_bind_lock, &lockstate); 5766 obj = dlcheck(arg); 5767 if (obj == NULL) 5768 obj = obj_from_addr(arg); 5769 if (obj == NULL) { 5770 _rtld_error("No shared object contains address"); 5771 lock_release(rtld_bind_lock, &lockstate); 5772 return (-1); 5773 } 5774 res = obj->dlopened ? 1 : 0; 5775 lock_release(rtld_bind_lock, &lockstate); 5776 return (res); 5777 } 5778 5779 static int 5780 obj_remap_relro(Obj_Entry *obj, int prot) 5781 { 5782 5783 if (obj->relro_size > 0 && mprotect(obj->relro_page, obj->relro_size, 5784 prot) == -1) { 5785 _rtld_error("%s: Cannot set relro protection to %#x: %s", 5786 obj->path, prot, rtld_strerror(errno)); 5787 return (-1); 5788 } 5789 return (0); 5790 } 5791 5792 static int 5793 obj_disable_relro(Obj_Entry *obj) 5794 { 5795 5796 return (obj_remap_relro(obj, PROT_READ | PROT_WRITE)); 5797 } 5798 5799 static int 5800 obj_enforce_relro(Obj_Entry *obj) 5801 { 5802 5803 return (obj_remap_relro(obj, PROT_READ)); 5804 } 5805 5806 static void 5807 map_stacks_exec(RtldLockState *lockstate) 5808 { 5809 void (*thr_map_stacks_exec)(void); 5810 5811 if ((max_stack_flags & PF_X) == 0 || (stack_prot & PROT_EXEC) != 0) 5812 return; 5813 thr_map_stacks_exec = (void (*)(void))(uintptr_t) 5814 get_program_var_addr("__pthread_map_stacks_exec", lockstate); 5815 if (thr_map_stacks_exec != NULL) { 5816 stack_prot |= PROT_EXEC; 5817 thr_map_stacks_exec(); 5818 } 5819 } 5820 5821 static void 5822 distribute_static_tls(Objlist *list, RtldLockState *lockstate) 5823 { 5824 Objlist_Entry *elm; 5825 Obj_Entry *obj; 5826 void (*distrib)(size_t, void *, size_t, size_t); 5827 5828 distrib = (void (*)(size_t, void *, size_t, size_t))(uintptr_t) 5829 get_program_var_addr("__pthread_distribute_static_tls", lockstate); 5830 if (distrib == NULL) 5831 return; 5832 STAILQ_FOREACH(elm, list, link) { 5833 obj = elm->obj; 5834 if (obj->marker || !obj->tls_done || obj->static_tls_copied) 5835 continue; 5836 distrib(obj->tlsoffset, obj->tlsinit, obj->tlsinitsize, 5837 obj->tlssize); 5838 obj->static_tls_copied = true; 5839 } 5840 } 5841 5842 void 5843 symlook_init(SymLook *dst, const char *name) 5844 { 5845 5846 bzero(dst, sizeof(*dst)); 5847 dst->name = name; 5848 dst->hash = elf_hash(name); 5849 dst->hash_gnu = gnu_hash(name); 5850 } 5851 5852 static void 5853 symlook_init_from_req(SymLook *dst, const SymLook *src) 5854 { 5855 5856 dst->name = src->name; 5857 dst->hash = src->hash; 5858 dst->hash_gnu = src->hash_gnu; 5859 dst->ventry = src->ventry; 5860 dst->flags = src->flags; 5861 dst->defobj_out = NULL; 5862 dst->sym_out = NULL; 5863 dst->lockstate = src->lockstate; 5864 } 5865 5866 static int 5867 open_binary_fd(const char *argv0, bool search_in_path, 5868 const char **binpath_res) 5869 { 5870 char *binpath, *pathenv, *pe, *res1; 5871 const char *res; 5872 int fd; 5873 5874 binpath = NULL; 5875 res = NULL; 5876 if (search_in_path && strchr(argv0, '/') == NULL) { 5877 binpath = xmalloc(PATH_MAX); 5878 pathenv = getenv("PATH"); 5879 if (pathenv == NULL) { 5880 _rtld_error("-p and no PATH environment variable"); 5881 rtld_die(); 5882 } 5883 pathenv = strdup(pathenv); 5884 if (pathenv == NULL) { 5885 _rtld_error("Cannot allocate memory"); 5886 rtld_die(); 5887 } 5888 fd = -1; 5889 errno = ENOENT; 5890 while ((pe = strsep(&pathenv, ":")) != NULL) { 5891 if (strlcpy(binpath, pe, PATH_MAX) >= PATH_MAX) 5892 continue; 5893 if (binpath[0] != '\0' && 5894 strlcat(binpath, "/", PATH_MAX) >= PATH_MAX) 5895 continue; 5896 if (strlcat(binpath, argv0, PATH_MAX) >= PATH_MAX) 5897 continue; 5898 fd = open(binpath, O_RDONLY | O_CLOEXEC | O_VERIFY); 5899 if (fd != -1 || errno != ENOENT) { 5900 res = binpath; 5901 break; 5902 } 5903 } 5904 free(pathenv); 5905 } else { 5906 fd = open(argv0, O_RDONLY | O_CLOEXEC | O_VERIFY); 5907 res = argv0; 5908 } 5909 5910 if (fd == -1) { 5911 _rtld_error("Cannot open %s: %s", argv0, rtld_strerror(errno)); 5912 rtld_die(); 5913 } 5914 if (res != NULL && res[0] != '/') { 5915 res1 = xmalloc(PATH_MAX); 5916 if (realpath(res, res1) != NULL) { 5917 if (res != argv0) 5918 free(__DECONST(char *, res)); 5919 res = res1; 5920 } else { 5921 free(res1); 5922 } 5923 } 5924 *binpath_res = res; 5925 return (fd); 5926 } 5927 5928 /* 5929 * Parse a set of command-line arguments. 5930 */ 5931 static int 5932 parse_args(char* argv[], int argc, bool *use_pathp, int *fdp, 5933 const char **argv0, bool *dir_ignore) 5934 { 5935 const char *arg; 5936 char machine[64]; 5937 size_t sz; 5938 int arglen, fd, i, j, mib[2]; 5939 char opt; 5940 bool seen_b, seen_f; 5941 5942 dbg("Parsing command-line arguments"); 5943 *use_pathp = false; 5944 *fdp = -1; 5945 *dir_ignore = false; 5946 seen_b = seen_f = false; 5947 5948 for (i = 1; i < argc; i++ ) { 5949 arg = argv[i]; 5950 dbg("argv[%d]: '%s'", i, arg); 5951 5952 /* 5953 * rtld arguments end with an explicit "--" or with the first 5954 * non-prefixed argument. 5955 */ 5956 if (strcmp(arg, "--") == 0) { 5957 i++; 5958 break; 5959 } 5960 if (arg[0] != '-') 5961 break; 5962 5963 /* 5964 * All other arguments are single-character options that can 5965 * be combined, so we need to search through `arg` for them. 5966 */ 5967 arglen = strlen(arg); 5968 for (j = 1; j < arglen; j++) { 5969 opt = arg[j]; 5970 if (opt == 'h') { 5971 print_usage(argv[0]); 5972 _exit(0); 5973 } else if (opt == 'b') { 5974 if (seen_f) { 5975 _rtld_error("Both -b and -f specified"); 5976 rtld_die(); 5977 } 5978 i++; 5979 *argv0 = argv[i]; 5980 seen_b = true; 5981 break; 5982 } else if (opt == 'd') { 5983 *dir_ignore = true; 5984 break; 5985 } else if (opt == 'f') { 5986 if (seen_b) { 5987 _rtld_error("Both -b and -f specified"); 5988 rtld_die(); 5989 } 5990 5991 /* 5992 * -f XX can be used to specify a 5993 * descriptor for the binary named at 5994 * the command line (i.e., the later 5995 * argument will specify the process 5996 * name but the descriptor is what 5997 * will actually be executed). 5998 * 5999 * -f must be the last option in, e.g., -abcf. 6000 */ 6001 if (j != arglen - 1) { 6002 _rtld_error("Invalid options: %s", arg); 6003 rtld_die(); 6004 } 6005 i++; 6006 fd = parse_integer(argv[i]); 6007 if (fd == -1) { 6008 _rtld_error( 6009 "Invalid file descriptor: '%s'", 6010 argv[i]); 6011 rtld_die(); 6012 } 6013 *fdp = fd; 6014 seen_f = true; 6015 break; 6016 } else if (opt == 'p') { 6017 *use_pathp = true; 6018 } else if (opt == 'u') { 6019 trust = false; 6020 } else if (opt == 'v') { 6021 machine[0] = '\0'; 6022 mib[0] = CTL_HW; 6023 mib[1] = HW_MACHINE; 6024 sz = sizeof(machine); 6025 sysctl(mib, nitems(mib), machine, &sz, NULL, 0); 6026 ld_elf_hints_path = ld_get_env_var( 6027 LD_ELF_HINTS_PATH); 6028 set_ld_elf_hints_path(); 6029 rtld_printf( 6030 "FreeBSD ld-elf.so.1 %s\n" 6031 "FreeBSD_version %d\n" 6032 "Default lib path %s\n" 6033 "Hints lib path %s\n" 6034 "Env prefix %s\n" 6035 "Default hint file %s\n" 6036 "Hint file %s\n" 6037 "libmap file %s\n", 6038 machine, 6039 __FreeBSD_version, ld_standard_library_path, 6040 gethints(false), 6041 ld_env_prefix, ld_elf_hints_default, 6042 ld_elf_hints_path, 6043 ld_path_libmap_conf); 6044 _exit(0); 6045 } else { 6046 _rtld_error("Invalid argument: '%s'", arg); 6047 print_usage(argv[0]); 6048 rtld_die(); 6049 } 6050 } 6051 } 6052 6053 if (!seen_b) 6054 *argv0 = argv[i]; 6055 return (i); 6056 } 6057 6058 /* 6059 * Parse a file descriptor number without pulling in more of libc (e.g. atoi). 6060 */ 6061 static int 6062 parse_integer(const char *str) 6063 { 6064 static const int RADIX = 10; /* XXXJA: possibly support hex? */ 6065 const char *orig; 6066 int n; 6067 char c; 6068 6069 orig = str; 6070 n = 0; 6071 for (c = *str; c != '\0'; c = *++str) { 6072 if (c < '0' || c > '9') 6073 return (-1); 6074 6075 n *= RADIX; 6076 n += c - '0'; 6077 } 6078 6079 /* Make sure we actually parsed something. */ 6080 if (str == orig) 6081 return (-1); 6082 return (n); 6083 } 6084 6085 static void 6086 print_usage(const char *argv0) 6087 { 6088 6089 rtld_printf( 6090 "Usage: %s [-h] [-b <exe>] [-d] [-f <FD>] [-p] [--] <binary> [<args>]\n" 6091 "\n" 6092 "Options:\n" 6093 " -h Display this help message\n" 6094 " -b <exe> Execute <exe> instead of <binary>, arg0 is <binary>\n" 6095 " -d Ignore lack of exec permissions for the binary\n" 6096 " -f <FD> Execute <FD> instead of searching for <binary>\n" 6097 " -p Search in PATH for named binary\n" 6098 " -u Ignore LD_ environment variables\n" 6099 " -v Display identification information\n" 6100 " -- End of RTLD options\n" 6101 " <binary> Name of process to execute\n" 6102 " <args> Arguments to the executed process\n", argv0); 6103 } 6104 6105 #define AUXFMT(at, xfmt) [at] = { .name = #at, .fmt = xfmt } 6106 static const struct auxfmt { 6107 const char *name; 6108 const char *fmt; 6109 } auxfmts[] = { 6110 AUXFMT(AT_NULL, NULL), 6111 AUXFMT(AT_IGNORE, NULL), 6112 AUXFMT(AT_EXECFD, "%ld"), 6113 AUXFMT(AT_PHDR, "%p"), 6114 AUXFMT(AT_PHENT, "%lu"), 6115 AUXFMT(AT_PHNUM, "%lu"), 6116 AUXFMT(AT_PAGESZ, "%lu"), 6117 AUXFMT(AT_BASE, "%#lx"), 6118 AUXFMT(AT_FLAGS, "%#lx"), 6119 AUXFMT(AT_ENTRY, "%p"), 6120 AUXFMT(AT_NOTELF, NULL), 6121 AUXFMT(AT_UID, "%ld"), 6122 AUXFMT(AT_EUID, "%ld"), 6123 AUXFMT(AT_GID, "%ld"), 6124 AUXFMT(AT_EGID, "%ld"), 6125 AUXFMT(AT_EXECPATH, "%s"), 6126 AUXFMT(AT_CANARY, "%p"), 6127 AUXFMT(AT_CANARYLEN, "%lu"), 6128 AUXFMT(AT_OSRELDATE, "%lu"), 6129 AUXFMT(AT_NCPUS, "%lu"), 6130 AUXFMT(AT_PAGESIZES, "%p"), 6131 AUXFMT(AT_PAGESIZESLEN, "%lu"), 6132 AUXFMT(AT_TIMEKEEP, "%p"), 6133 AUXFMT(AT_STACKPROT, "%#lx"), 6134 AUXFMT(AT_EHDRFLAGS, "%#lx"), 6135 AUXFMT(AT_HWCAP, "%#lx"), 6136 AUXFMT(AT_HWCAP2, "%#lx"), 6137 AUXFMT(AT_BSDFLAGS, "%#lx"), 6138 AUXFMT(AT_ARGC, "%lu"), 6139 AUXFMT(AT_ARGV, "%p"), 6140 AUXFMT(AT_ENVC, "%p"), 6141 AUXFMT(AT_ENVV, "%p"), 6142 AUXFMT(AT_PS_STRINGS, "%p"), 6143 AUXFMT(AT_FXRNG, "%p"), 6144 AUXFMT(AT_KPRELOAD, "%p"), 6145 }; 6146 6147 static bool 6148 is_ptr_fmt(const char *fmt) 6149 { 6150 char last; 6151 6152 last = fmt[strlen(fmt) - 1]; 6153 return (last == 'p' || last == 's'); 6154 } 6155 6156 static void 6157 dump_auxv(Elf_Auxinfo **aux_info) 6158 { 6159 Elf_Auxinfo *auxp; 6160 const struct auxfmt *fmt; 6161 int i; 6162 6163 for (i = 0; i < AT_COUNT; i++) { 6164 auxp = aux_info[i]; 6165 if (auxp == NULL) 6166 continue; 6167 fmt = &auxfmts[i]; 6168 if (fmt->fmt == NULL) 6169 continue; 6170 rtld_fdprintf(STDOUT_FILENO, "%s:\t", fmt->name); 6171 if (is_ptr_fmt(fmt->fmt)) { 6172 rtld_fdprintfx(STDOUT_FILENO, fmt->fmt, 6173 auxp->a_un.a_ptr); 6174 } else { 6175 rtld_fdprintfx(STDOUT_FILENO, fmt->fmt, 6176 auxp->a_un.a_val); 6177 } 6178 rtld_fdprintf(STDOUT_FILENO, "\n"); 6179 } 6180 } 6181 6182 /* 6183 * Overrides for libc_pic-provided functions. 6184 */ 6185 6186 int 6187 __getosreldate(void) 6188 { 6189 size_t len; 6190 int oid[2]; 6191 int error, osrel; 6192 6193 if (osreldate != 0) 6194 return (osreldate); 6195 6196 oid[0] = CTL_KERN; 6197 oid[1] = KERN_OSRELDATE; 6198 osrel = 0; 6199 len = sizeof(osrel); 6200 error = sysctl(oid, 2, &osrel, &len, NULL, 0); 6201 if (error == 0 && osrel > 0 && len == sizeof(osrel)) 6202 osreldate = osrel; 6203 return (osreldate); 6204 } 6205 const char * 6206 rtld_strerror(int errnum) 6207 { 6208 6209 if (errnum < 0 || errnum >= sys_nerr) 6210 return ("Unknown error"); 6211 return (sys_errlist[errnum]); 6212 } 6213 6214 char * 6215 getenv(const char *name) 6216 { 6217 return (__DECONST(char *, rtld_get_env_val(environ, name, 6218 strlen(name)))); 6219 } 6220 6221 /* malloc */ 6222 void * 6223 malloc(size_t nbytes) 6224 { 6225 6226 return (__crt_malloc(nbytes)); 6227 } 6228 6229 void * 6230 calloc(size_t num, size_t size) 6231 { 6232 6233 return (__crt_calloc(num, size)); 6234 } 6235 6236 void 6237 free(void *cp) 6238 { 6239 6240 __crt_free(cp); 6241 } 6242 6243 void * 6244 realloc(void *cp, size_t nbytes) 6245 { 6246 6247 return (__crt_realloc(cp, nbytes)); 6248 } 6249 6250 extern int _rtld_version__FreeBSD_version __exported; 6251 int _rtld_version__FreeBSD_version = __FreeBSD_version; 6252 6253 extern char _rtld_version_laddr_offset __exported; 6254 char _rtld_version_laddr_offset; 6255 6256 extern char _rtld_version_dlpi_tls_data __exported; 6257 char _rtld_version_dlpi_tls_data; 6258