1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 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/param.h> 42 #include <sys/mount.h> 43 #include <sys/mman.h> 44 #include <sys/stat.h> 45 #include <sys/sysctl.h> 46 #include <sys/uio.h> 47 #include <sys/utsname.h> 48 #include <sys/ktrace.h> 49 50 #include <dlfcn.h> 51 #include <err.h> 52 #include <errno.h> 53 #include <fcntl.h> 54 #include <stdarg.h> 55 #include <stdio.h> 56 #include <stdlib.h> 57 #include <string.h> 58 #include <unistd.h> 59 60 #include "debug.h" 61 #include "rtld.h" 62 #include "libmap.h" 63 #include "rtld_paths.h" 64 #include "rtld_tls.h" 65 #include "rtld_printf.h" 66 #include "rtld_malloc.h" 67 #include "rtld_utrace.h" 68 #include "notes.h" 69 #include "rtld_libc.h" 70 71 /* Types. */ 72 typedef void (*func_ptr_type)(void); 73 typedef void * (*path_enum_proc) (const char *path, size_t len, void *arg); 74 75 76 /* Variables that cannot be static: */ 77 extern struct r_debug r_debug; /* For GDB */ 78 extern int _thread_autoinit_dummy_decl; 79 extern void (*__cleanup)(void); 80 81 struct dlerror_save { 82 int seen; 83 char *msg; 84 }; 85 86 /* 87 * Function declarations. 88 */ 89 static const char *basename(const char *); 90 static void digest_dynamic1(Obj_Entry *, int, const Elf_Dyn **, 91 const Elf_Dyn **, const Elf_Dyn **); 92 static bool digest_dynamic2(Obj_Entry *, const Elf_Dyn *, const Elf_Dyn *, 93 const Elf_Dyn *); 94 static bool digest_dynamic(Obj_Entry *, int); 95 static Obj_Entry *digest_phdr(const Elf_Phdr *, int, caddr_t, const char *); 96 static void distribute_static_tls(Objlist *, RtldLockState *); 97 static Obj_Entry *dlcheck(void *); 98 static int dlclose_locked(void *, RtldLockState *); 99 static Obj_Entry *dlopen_object(const char *name, int fd, Obj_Entry *refobj, 100 int lo_flags, int mode, RtldLockState *lockstate); 101 static Obj_Entry *do_load_object(int, const char *, char *, struct stat *, int); 102 static int do_search_info(const Obj_Entry *obj, int, struct dl_serinfo *); 103 static bool donelist_check(DoneList *, const Obj_Entry *); 104 static void dump_auxv(Elf_Auxinfo **aux_info); 105 static void errmsg_restore(struct dlerror_save *); 106 static struct dlerror_save *errmsg_save(void); 107 static void *fill_search_info(const char *, size_t, void *); 108 static char *find_library(const char *, const Obj_Entry *, int *); 109 static const char *gethints(bool); 110 static void hold_object(Obj_Entry *); 111 static void unhold_object(Obj_Entry *); 112 static void init_dag(Obj_Entry *); 113 static void init_marker(Obj_Entry *); 114 static void init_pagesizes(Elf_Auxinfo **aux_info); 115 static void init_rtld(caddr_t, Elf_Auxinfo **); 116 static void initlist_add_neededs(Needed_Entry *, Objlist *); 117 static void initlist_add_objects(Obj_Entry *, Obj_Entry *, Objlist *); 118 static int initlist_objects_ifunc(Objlist *, bool, int, RtldLockState *); 119 static void linkmap_add(Obj_Entry *); 120 static void linkmap_delete(Obj_Entry *); 121 static void load_filtees(Obj_Entry *, int flags, RtldLockState *); 122 static void unload_filtees(Obj_Entry *, RtldLockState *); 123 static int load_needed_objects(Obj_Entry *, int); 124 static int load_preload_objects(const char *, bool); 125 static int load_kpreload(const void *addr); 126 static Obj_Entry *load_object(const char *, int fd, const Obj_Entry *, int); 127 static void map_stacks_exec(RtldLockState *); 128 static int obj_disable_relro(Obj_Entry *); 129 static int obj_enforce_relro(Obj_Entry *); 130 static void objlist_call_fini(Objlist *, Obj_Entry *, RtldLockState *); 131 static void objlist_call_init(Objlist *, RtldLockState *); 132 static void objlist_clear(Objlist *); 133 static Objlist_Entry *objlist_find(Objlist *, const Obj_Entry *); 134 static void objlist_init(Objlist *); 135 static void objlist_push_head(Objlist *, Obj_Entry *); 136 static void objlist_push_tail(Objlist *, Obj_Entry *); 137 static void objlist_put_after(Objlist *, Obj_Entry *, Obj_Entry *); 138 static void objlist_remove(Objlist *, Obj_Entry *); 139 static int open_binary_fd(const char *argv0, bool search_in_path, 140 const char **binpath_res); 141 static int parse_args(char* argv[], int argc, bool *use_pathp, int *fdp, 142 const char **argv0, bool *dir_ignore); 143 static int parse_integer(const char *); 144 static void *path_enumerate(const char *, path_enum_proc, const char *, void *); 145 static void print_usage(const char *argv0); 146 static void release_object(Obj_Entry *); 147 static int relocate_object_dag(Obj_Entry *root, bool bind_now, 148 Obj_Entry *rtldobj, int flags, RtldLockState *lockstate); 149 static int relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, 150 int flags, RtldLockState *lockstate); 151 static int relocate_objects(Obj_Entry *, bool, Obj_Entry *, int, 152 RtldLockState *); 153 static int resolve_object_ifunc(Obj_Entry *, bool, int, RtldLockState *); 154 static int rtld_dirname(const char *, char *); 155 static int rtld_dirname_abs(const char *, char *); 156 static void *rtld_dlopen(const char *name, int fd, int mode); 157 static void rtld_exit(void); 158 static void rtld_nop_exit(void); 159 static char *search_library_path(const char *, const char *, const char *, 160 int *); 161 static char *search_library_pathfds(const char *, const char *, int *); 162 static const void **get_program_var_addr(const char *, RtldLockState *); 163 static void set_program_var(const char *, const void *); 164 static int symlook_default(SymLook *, const Obj_Entry *refobj); 165 static int symlook_global(SymLook *, DoneList *); 166 static void symlook_init_from_req(SymLook *, const SymLook *); 167 static int symlook_list(SymLook *, const Objlist *, DoneList *); 168 static int symlook_needed(SymLook *, const Needed_Entry *, DoneList *); 169 static int symlook_obj1_sysv(SymLook *, const Obj_Entry *); 170 static int symlook_obj1_gnu(SymLook *, const Obj_Entry *); 171 static void *tls_get_addr_slow(Elf_Addr **, int, size_t, bool) __noinline; 172 static void trace_loaded_objects(Obj_Entry *, bool); 173 static void unlink_object(Obj_Entry *); 174 static void unload_object(Obj_Entry *, RtldLockState *lockstate); 175 static void unref_dag(Obj_Entry *); 176 static void ref_dag(Obj_Entry *); 177 static char *origin_subst_one(Obj_Entry *, char *, const char *, 178 const char *, bool); 179 static char *origin_subst(Obj_Entry *, const char *); 180 static bool obj_resolve_origin(Obj_Entry *obj); 181 static void preinit_main(void); 182 static int rtld_verify_versions(const Objlist *); 183 static int rtld_verify_object_versions(Obj_Entry *); 184 static void object_add_name(Obj_Entry *, const char *); 185 static int object_match_name(const Obj_Entry *, const char *); 186 static void ld_utrace_log(int, void *, void *, size_t, int, const char *); 187 static void rtld_fill_dl_phdr_info(const Obj_Entry *obj, 188 struct dl_phdr_info *phdr_info); 189 static uint32_t gnu_hash(const char *); 190 static bool matched_symbol(SymLook *, const Obj_Entry *, Sym_Match_Result *, 191 const unsigned long); 192 193 void r_debug_state(struct r_debug *, struct link_map *) __noinline __exported; 194 void _r_debug_postinit(struct link_map *) __noinline __exported; 195 196 int __sys_openat(int, const char *, int, ...); 197 198 /* 199 * Data declarations. 200 */ 201 struct r_debug r_debug __exported; /* for GDB; */ 202 static bool libmap_disable; /* Disable libmap */ 203 static bool ld_loadfltr; /* Immediate filters processing */ 204 static const char *libmap_override;/* Maps to use in addition to libmap.conf */ 205 static bool trust; /* False for setuid and setgid programs */ 206 static bool dangerous_ld_env; /* True if environment variables have been 207 used to affect the libraries loaded */ 208 bool ld_bind_not; /* Disable PLT update */ 209 static const char *ld_bind_now; /* Environment variable for immediate binding */ 210 static const char *ld_debug; /* Environment variable for debugging */ 211 static bool ld_dynamic_weak = true; /* True if non-weak definition overrides 212 weak definition */ 213 static const char *ld_library_path;/* Environment variable for search path */ 214 static const char *ld_library_dirs;/* Environment variable for library descriptors */ 215 static const char *ld_preload; /* Environment variable for libraries to 216 load first */ 217 static const char *ld_preload_fds;/* Environment variable for libraries represented by 218 descriptors */ 219 static const char *ld_elf_hints_path; /* Environment variable for alternative hints path */ 220 static const char *ld_tracing; /* Called from ldd to print libs */ 221 static const char *ld_utrace; /* Use utrace() to log events. */ 222 static struct obj_entry_q obj_list; /* Queue of all loaded objects */ 223 static Obj_Entry *obj_main; /* The main program shared object */ 224 static Obj_Entry obj_rtld; /* The dynamic linker shared object */ 225 static unsigned int obj_count; /* Number of objects in obj_list */ 226 static unsigned int obj_loads; /* Number of loads of objects (gen count) */ 227 size_t ld_static_tls_extra = /* Static TLS extra space (bytes) */ 228 RTLD_STATIC_TLS_EXTRA; 229 230 static Objlist list_global = /* Objects dlopened with RTLD_GLOBAL */ 231 STAILQ_HEAD_INITIALIZER(list_global); 232 static Objlist list_main = /* Objects loaded at program startup */ 233 STAILQ_HEAD_INITIALIZER(list_main); 234 static Objlist list_fini = /* Objects needing fini() calls */ 235 STAILQ_HEAD_INITIALIZER(list_fini); 236 237 Elf_Sym sym_zero; /* For resolving undefined weak refs. */ 238 239 #define GDB_STATE(s,m) r_debug.r_state = s; r_debug_state(&r_debug,m); 240 241 extern Elf_Dyn _DYNAMIC; 242 #pragma weak _DYNAMIC 243 244 int dlclose(void *) __exported; 245 char *dlerror(void) __exported; 246 void *dlopen(const char *, int) __exported; 247 void *fdlopen(int, int) __exported; 248 void *dlsym(void *, const char *) __exported; 249 dlfunc_t dlfunc(void *, const char *) __exported; 250 void *dlvsym(void *, const char *, const char *) __exported; 251 int dladdr(const void *, Dl_info *) __exported; 252 void dllockinit(void *, void *(*)(void *), void (*)(void *), void (*)(void *), 253 void (*)(void *), void (*)(void *), void (*)(void *)) __exported; 254 int dlinfo(void *, int , void *) __exported; 255 int dl_iterate_phdr(__dl_iterate_hdr_callback, void *) __exported; 256 int _rtld_addr_phdr(const void *, struct dl_phdr_info *) __exported; 257 int _rtld_get_stack_prot(void) __exported; 258 int _rtld_is_dlopened(void *) __exported; 259 void _rtld_error(const char *, ...) __exported; 260 261 /* Only here to fix -Wmissing-prototypes warnings */ 262 int __getosreldate(void); 263 func_ptr_type _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp); 264 Elf_Addr _rtld_bind(Obj_Entry *obj, Elf_Size reloff); 265 266 int npagesizes; 267 static int osreldate; 268 size_t *pagesizes; 269 size_t page_size; 270 271 static int stack_prot = PROT_READ | PROT_WRITE | PROT_EXEC; 272 static int max_stack_flags; 273 274 /* 275 * Global declarations normally provided by crt1. The dynamic linker is 276 * not built with crt1, so we have to provide them ourselves. 277 */ 278 char *__progname; 279 char **environ; 280 281 /* 282 * Used to pass argc, argv to init functions. 283 */ 284 int main_argc; 285 char **main_argv; 286 287 /* 288 * Globals to control TLS allocation. 289 */ 290 size_t tls_last_offset; /* Static TLS offset of last module */ 291 size_t tls_last_size; /* Static TLS size of last module */ 292 size_t tls_static_space; /* Static TLS space allocated */ 293 static size_t tls_static_max_align; 294 Elf_Addr tls_dtv_generation = 1; /* Used to detect when dtv size changes */ 295 int tls_max_index = 1; /* Largest module index allocated */ 296 297 static bool ld_library_path_rpath = false; 298 bool ld_fast_sigblock = false; 299 300 /* 301 * Globals for path names, and such 302 */ 303 const char *ld_elf_hints_default = _PATH_ELF_HINTS; 304 const char *ld_path_libmap_conf = _PATH_LIBMAP_CONF; 305 const char *ld_path_rtld = _PATH_RTLD; 306 const char *ld_standard_library_path = STANDARD_LIBRARY_PATH; 307 const char *ld_env_prefix = LD_; 308 309 static void (*rtld_exit_ptr)(void); 310 311 /* 312 * Fill in a DoneList with an allocation large enough to hold all of 313 * the currently-loaded objects. Keep this as a macro since it calls 314 * alloca and we want that to occur within the scope of the caller. 315 */ 316 #define donelist_init(dlp) \ 317 ((dlp)->objs = alloca(obj_count * sizeof (dlp)->objs[0]), \ 318 assert((dlp)->objs != NULL), \ 319 (dlp)->num_alloc = obj_count, \ 320 (dlp)->num_used = 0) 321 322 #define LD_UTRACE(e, h, mb, ms, r, n) do { \ 323 if (ld_utrace != NULL) \ 324 ld_utrace_log(e, h, mb, ms, r, n); \ 325 } while (0) 326 327 static void 328 ld_utrace_log(int event, void *handle, void *mapbase, size_t mapsize, 329 int refcnt, const char *name) 330 { 331 struct utrace_rtld ut; 332 static const char rtld_utrace_sig[RTLD_UTRACE_SIG_SZ] = RTLD_UTRACE_SIG; 333 334 memcpy(ut.sig, rtld_utrace_sig, sizeof(ut.sig)); 335 ut.event = event; 336 ut.handle = handle; 337 ut.mapbase = mapbase; 338 ut.mapsize = mapsize; 339 ut.refcnt = refcnt; 340 bzero(ut.name, sizeof(ut.name)); 341 if (name) 342 strlcpy(ut.name, name, sizeof(ut.name)); 343 utrace(&ut, sizeof(ut)); 344 } 345 346 enum { 347 LD_BIND_NOW = 0, 348 LD_PRELOAD, 349 LD_LIBMAP, 350 LD_LIBRARY_PATH, 351 LD_LIBRARY_PATH_FDS, 352 LD_LIBMAP_DISABLE, 353 LD_BIND_NOT, 354 LD_DEBUG, 355 LD_ELF_HINTS_PATH, 356 LD_LOADFLTR, 357 LD_LIBRARY_PATH_RPATH, 358 LD_PRELOAD_FDS, 359 LD_DYNAMIC_WEAK, 360 LD_TRACE_LOADED_OBJECTS, 361 LD_UTRACE, 362 LD_DUMP_REL_PRE, 363 LD_DUMP_REL_POST, 364 LD_TRACE_LOADED_OBJECTS_PROGNAME, 365 LD_TRACE_LOADED_OBJECTS_FMT1, 366 LD_TRACE_LOADED_OBJECTS_FMT2, 367 LD_TRACE_LOADED_OBJECTS_ALL, 368 LD_SHOW_AUXV, 369 LD_STATIC_TLS_EXTRA, 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 LD_ENV_DESC(STATIC_TLS_EXTRA, false), 404 }; 405 406 static const char * 407 ld_get_env_var(int idx) 408 { 409 return (ld_env_vars[idx].val); 410 } 411 412 static const char * 413 rtld_get_env_val(char **env, const char *name, size_t name_len) 414 { 415 char **m, *n, *v; 416 417 for (m = env; *m != NULL; m++) { 418 n = *m; 419 v = strchr(n, '='); 420 if (v == NULL) { 421 /* corrupt environment? */ 422 continue; 423 } 424 if (v - n == (ptrdiff_t)name_len && 425 strncmp(name, n, name_len) == 0) 426 return (v + 1); 427 } 428 return (NULL); 429 } 430 431 static void 432 rtld_init_env_vars_for_prefix(char **env, const char *env_prefix) 433 { 434 struct ld_env_var_desc *lvd; 435 size_t prefix_len, nlen; 436 char **m, *n, *v; 437 int i; 438 439 prefix_len = strlen(env_prefix); 440 for (m = env; *m != NULL; m++) { 441 n = *m; 442 if (strncmp(env_prefix, n, prefix_len) != 0) { 443 /* Not a rtld environment variable. */ 444 continue; 445 } 446 n += prefix_len; 447 v = strchr(n, '='); 448 if (v == NULL) { 449 /* corrupt environment? */ 450 continue; 451 } 452 for (i = 0; i < (int)nitems(ld_env_vars); i++) { 453 lvd = &ld_env_vars[i]; 454 if (lvd->val != NULL) { 455 /* Saw higher-priority variable name already. */ 456 continue; 457 } 458 nlen = strlen(lvd->n); 459 if (v - n == (ptrdiff_t)nlen && 460 strncmp(lvd->n, n, nlen) == 0) { 461 lvd->val = v + 1; 462 break; 463 } 464 } 465 } 466 } 467 468 static void 469 rtld_init_env_vars(char **env) 470 { 471 rtld_init_env_vars_for_prefix(env, ld_env_prefix); 472 } 473 474 static void 475 set_ld_elf_hints_path(void) 476 { 477 if (ld_elf_hints_path == NULL || strlen(ld_elf_hints_path) == 0) 478 ld_elf_hints_path = ld_elf_hints_default; 479 } 480 481 uintptr_t 482 rtld_round_page(uintptr_t x) 483 { 484 return (roundup2(x, page_size)); 485 } 486 487 uintptr_t 488 rtld_trunc_page(uintptr_t x) 489 { 490 return (rounddown2(x, page_size)); 491 } 492 493 /* 494 * Main entry point for dynamic linking. The first argument is the 495 * stack pointer. The stack is expected to be laid out as described 496 * in the SVR4 ABI specification, Intel 386 Processor Supplement. 497 * Specifically, the stack pointer points to a word containing 498 * ARGC. Following that in the stack is a null-terminated sequence 499 * of pointers to argument strings. Then comes a null-terminated 500 * sequence of pointers to environment strings. Finally, there is a 501 * sequence of "auxiliary vector" entries. 502 * 503 * The second argument points to a place to store the dynamic linker's 504 * exit procedure pointer and the third to a place to store the main 505 * program's object. 506 * 507 * The return value is the main program's entry point. 508 */ 509 func_ptr_type 510 _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp) 511 { 512 Elf_Auxinfo *aux, *auxp, *auxpf, *aux_info[AT_COUNT]; 513 Objlist_Entry *entry; 514 Obj_Entry *last_interposer, *obj, *preload_tail; 515 const Elf_Phdr *phdr; 516 Objlist initlist; 517 RtldLockState lockstate; 518 struct stat st; 519 Elf_Addr *argcp; 520 char **argv, **env, **envp, *kexecpath; 521 const char *argv0, *binpath, *library_path_rpath, *static_tls_extra; 522 struct ld_env_var_desc *lvd; 523 caddr_t imgentry; 524 char buf[MAXPATHLEN]; 525 int argc, fd, i, mib[4], old_osrel, osrel, phnum, rtld_argc; 526 size_t sz; 527 #ifdef __powerpc__ 528 int old_auxv_format = 1; 529 #endif 530 bool dir_enable, dir_ignore, direct_exec, explicit_fd, search_in_path; 531 532 /* 533 * On entry, the dynamic linker itself has not been relocated yet. 534 * Be very careful not to reference any global data until after 535 * init_rtld has returned. It is OK to reference file-scope statics 536 * and string constants, and to call static and global functions. 537 */ 538 539 /* Find the auxiliary vector on the stack. */ 540 argcp = sp; 541 argc = *sp++; 542 argv = (char **) sp; 543 sp += argc + 1; /* Skip over arguments and NULL terminator */ 544 env = (char **) sp; 545 while (*sp++ != 0) /* Skip over environment, and NULL terminator */ 546 ; 547 aux = (Elf_Auxinfo *) sp; 548 549 /* Digest the auxiliary vector. */ 550 for (i = 0; i < AT_COUNT; i++) 551 aux_info[i] = NULL; 552 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) { 553 if (auxp->a_type < AT_COUNT) 554 aux_info[auxp->a_type] = auxp; 555 #ifdef __powerpc__ 556 if (auxp->a_type == 23) /* AT_STACKPROT */ 557 old_auxv_format = 0; 558 #endif 559 } 560 561 #ifdef __powerpc__ 562 if (old_auxv_format) { 563 /* Remap from old-style auxv numbers. */ 564 aux_info[23] = aux_info[21]; /* AT_STACKPROT */ 565 aux_info[21] = aux_info[19]; /* AT_PAGESIZESLEN */ 566 aux_info[19] = aux_info[17]; /* AT_NCPUS */ 567 aux_info[17] = aux_info[15]; /* AT_CANARYLEN */ 568 aux_info[15] = aux_info[13]; /* AT_EXECPATH */ 569 aux_info[13] = NULL; /* AT_GID */ 570 571 aux_info[20] = aux_info[18]; /* AT_PAGESIZES */ 572 aux_info[18] = aux_info[16]; /* AT_OSRELDATE */ 573 aux_info[16] = aux_info[14]; /* AT_CANARY */ 574 aux_info[14] = NULL; /* AT_EGID */ 575 } 576 #endif 577 578 /* Initialize and relocate ourselves. */ 579 assert(aux_info[AT_BASE] != NULL); 580 init_rtld((caddr_t) aux_info[AT_BASE]->a_un.a_ptr, aux_info); 581 582 dlerror_dflt_init(); 583 584 __progname = obj_rtld.path; 585 argv0 = argv[0] != NULL ? argv[0] : "(null)"; 586 environ = env; 587 main_argc = argc; 588 main_argv = argv; 589 590 if (aux_info[AT_BSDFLAGS] != NULL && 591 (aux_info[AT_BSDFLAGS]->a_un.a_val & ELF_BSDF_SIGFASTBLK) != 0) 592 ld_fast_sigblock = true; 593 594 trust = !issetugid(); 595 direct_exec = false; 596 597 md_abi_variant_hook(aux_info); 598 rtld_init_env_vars(env); 599 600 fd = -1; 601 if (aux_info[AT_EXECFD] != NULL) { 602 fd = aux_info[AT_EXECFD]->a_un.a_val; 603 } else { 604 assert(aux_info[AT_PHDR] != NULL); 605 phdr = (const Elf_Phdr *)aux_info[AT_PHDR]->a_un.a_ptr; 606 if (phdr == obj_rtld.phdr) { 607 if (!trust) { 608 _rtld_error("Tainted process refusing to run binary %s", 609 argv0); 610 rtld_die(); 611 } 612 direct_exec = true; 613 614 dbg("opening main program in direct exec mode"); 615 if (argc >= 2) { 616 rtld_argc = parse_args(argv, argc, &search_in_path, &fd, 617 &argv0, &dir_ignore); 618 explicit_fd = (fd != -1); 619 binpath = NULL; 620 if (!explicit_fd) 621 fd = open_binary_fd(argv0, search_in_path, &binpath); 622 if (fstat(fd, &st) == -1) { 623 _rtld_error("Failed to fstat FD %d (%s): %s", fd, 624 explicit_fd ? "user-provided descriptor" : argv0, 625 rtld_strerror(errno)); 626 rtld_die(); 627 } 628 629 /* 630 * Rough emulation of the permission checks done by 631 * execve(2), only Unix DACs are checked, ACLs are 632 * ignored. Preserve the semantic of disabling owner 633 * to execute if owner x bit is cleared, even if 634 * others x bit is enabled. 635 * mmap(2) does not allow to mmap with PROT_EXEC if 636 * binary' file comes from noexec mount. We cannot 637 * set a text reference on the binary. 638 */ 639 dir_enable = false; 640 if (st.st_uid == geteuid()) { 641 if ((st.st_mode & S_IXUSR) != 0) 642 dir_enable = true; 643 } else if (st.st_gid == getegid()) { 644 if ((st.st_mode & S_IXGRP) != 0) 645 dir_enable = true; 646 } else if ((st.st_mode & S_IXOTH) != 0) { 647 dir_enable = true; 648 } 649 if (!dir_enable && !dir_ignore) { 650 _rtld_error("No execute permission for binary %s", 651 argv0); 652 rtld_die(); 653 } 654 655 /* 656 * For direct exec mode, argv[0] is the interpreter 657 * name, we must remove it and shift arguments left 658 * before invoking binary main. Since stack layout 659 * places environment pointers and aux vectors right 660 * after the terminating NULL, we must shift 661 * environment and aux as well. 662 */ 663 main_argc = argc - rtld_argc; 664 for (i = 0; i <= main_argc; i++) 665 argv[i] = argv[i + rtld_argc]; 666 *argcp -= rtld_argc; 667 environ = env = envp = argv + main_argc + 1; 668 dbg("move env from %p to %p", envp + rtld_argc, envp); 669 do { 670 *envp = *(envp + rtld_argc); 671 } while (*envp++ != NULL); 672 aux = auxp = (Elf_Auxinfo *)envp; 673 auxpf = (Elf_Auxinfo *)(envp + rtld_argc); 674 dbg("move aux from %p to %p", auxpf, aux); 675 /* XXXKIB insert place for AT_EXECPATH if not present */ 676 for (;; auxp++, auxpf++) { 677 *auxp = *auxpf; 678 if (auxp->a_type == AT_NULL) 679 break; 680 } 681 /* Since the auxiliary vector has moved, redigest it. */ 682 for (i = 0; i < AT_COUNT; i++) 683 aux_info[i] = NULL; 684 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) { 685 if (auxp->a_type < AT_COUNT) 686 aux_info[auxp->a_type] = auxp; 687 } 688 689 /* Point AT_EXECPATH auxv and aux_info to the binary path. */ 690 if (binpath == NULL) { 691 aux_info[AT_EXECPATH] = NULL; 692 } else { 693 if (aux_info[AT_EXECPATH] == NULL) { 694 aux_info[AT_EXECPATH] = xmalloc(sizeof(Elf_Auxinfo)); 695 aux_info[AT_EXECPATH]->a_type = AT_EXECPATH; 696 } 697 aux_info[AT_EXECPATH]->a_un.a_ptr = __DECONST(void *, 698 binpath); 699 } 700 } else { 701 _rtld_error("No binary"); 702 rtld_die(); 703 } 704 } 705 } 706 707 ld_bind_now = ld_get_env_var(LD_BIND_NOW); 708 709 /* 710 * If the process is tainted, then we un-set the dangerous environment 711 * variables. The process will be marked as tainted until setuid(2) 712 * is called. If any child process calls setuid(2) we do not want any 713 * future processes to honor the potentially un-safe variables. 714 */ 715 if (!trust) { 716 for (i = 0; i < (int)nitems(ld_env_vars); i++) { 717 lvd = &ld_env_vars[i]; 718 if (lvd->unsecure) 719 lvd->val = NULL; 720 } 721 } 722 723 ld_debug = ld_get_env_var(LD_DEBUG); 724 if (ld_bind_now == NULL) 725 ld_bind_not = ld_get_env_var(LD_BIND_NOT) != NULL; 726 ld_dynamic_weak = ld_get_env_var(LD_DYNAMIC_WEAK) == NULL; 727 libmap_disable = ld_get_env_var(LD_LIBMAP_DISABLE) != NULL; 728 libmap_override = ld_get_env_var(LD_LIBMAP); 729 ld_library_path = ld_get_env_var(LD_LIBRARY_PATH); 730 ld_library_dirs = ld_get_env_var(LD_LIBRARY_PATH_FDS); 731 ld_preload = ld_get_env_var(LD_PRELOAD); 732 ld_preload_fds = ld_get_env_var(LD_PRELOAD_FDS); 733 ld_elf_hints_path = ld_get_env_var(LD_ELF_HINTS_PATH); 734 ld_loadfltr = ld_get_env_var(LD_LOADFLTR) != NULL; 735 library_path_rpath = ld_get_env_var(LD_LIBRARY_PATH_RPATH); 736 if (library_path_rpath != NULL) { 737 if (library_path_rpath[0] == 'y' || 738 library_path_rpath[0] == 'Y' || 739 library_path_rpath[0] == '1') 740 ld_library_path_rpath = true; 741 else 742 ld_library_path_rpath = false; 743 } 744 static_tls_extra = ld_get_env_var(LD_STATIC_TLS_EXTRA); 745 if (static_tls_extra != NULL && static_tls_extra[0] != '\0') { 746 sz = parse_integer(static_tls_extra); 747 if (sz >= RTLD_STATIC_TLS_EXTRA && sz <= SIZE_T_MAX) 748 ld_static_tls_extra = sz; 749 } 750 dangerous_ld_env = libmap_disable || libmap_override != NULL || 751 ld_library_path != NULL || ld_preload != NULL || 752 ld_elf_hints_path != NULL || ld_loadfltr || !ld_dynamic_weak || 753 static_tls_extra != NULL; 754 ld_tracing = ld_get_env_var(LD_TRACE_LOADED_OBJECTS); 755 ld_utrace = ld_get_env_var(LD_UTRACE); 756 757 set_ld_elf_hints_path(); 758 if (ld_debug != NULL && *ld_debug != '\0') 759 debug = 1; 760 dbg("%s is initialized, base address = %p", __progname, 761 (caddr_t) aux_info[AT_BASE]->a_un.a_ptr); 762 dbg("RTLD dynamic = %p", obj_rtld.dynamic); 763 dbg("RTLD pltgot = %p", obj_rtld.pltgot); 764 765 dbg("initializing thread locks"); 766 lockdflt_init(); 767 768 /* 769 * Load the main program, or process its program header if it is 770 * already loaded. 771 */ 772 if (fd != -1) { /* Load the main program. */ 773 dbg("loading main program"); 774 obj_main = map_object(fd, argv0, NULL); 775 close(fd); 776 if (obj_main == NULL) 777 rtld_die(); 778 max_stack_flags = obj_main->stack_flags; 779 } else { /* Main program already loaded. */ 780 dbg("processing main program's program header"); 781 assert(aux_info[AT_PHDR] != NULL); 782 phdr = (const Elf_Phdr *) aux_info[AT_PHDR]->a_un.a_ptr; 783 assert(aux_info[AT_PHNUM] != NULL); 784 phnum = aux_info[AT_PHNUM]->a_un.a_val; 785 assert(aux_info[AT_PHENT] != NULL); 786 assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr)); 787 assert(aux_info[AT_ENTRY] != NULL); 788 imgentry = (caddr_t) aux_info[AT_ENTRY]->a_un.a_ptr; 789 if ((obj_main = digest_phdr(phdr, phnum, imgentry, argv0)) == NULL) 790 rtld_die(); 791 } 792 793 if (aux_info[AT_EXECPATH] != NULL && fd == -1) { 794 kexecpath = aux_info[AT_EXECPATH]->a_un.a_ptr; 795 dbg("AT_EXECPATH %p %s", kexecpath, kexecpath); 796 if (kexecpath[0] == '/') 797 obj_main->path = kexecpath; 798 else if (getcwd(buf, sizeof(buf)) == NULL || 799 strlcat(buf, "/", sizeof(buf)) >= sizeof(buf) || 800 strlcat(buf, kexecpath, sizeof(buf)) >= sizeof(buf)) 801 obj_main->path = xstrdup(argv0); 802 else 803 obj_main->path = xstrdup(buf); 804 } else { 805 dbg("No AT_EXECPATH or direct exec"); 806 obj_main->path = xstrdup(argv0); 807 } 808 dbg("obj_main path %s", obj_main->path); 809 obj_main->mainprog = true; 810 811 if (aux_info[AT_STACKPROT] != NULL && 812 aux_info[AT_STACKPROT]->a_un.a_val != 0) 813 stack_prot = aux_info[AT_STACKPROT]->a_un.a_val; 814 815 #ifndef COMPAT_libcompat 816 /* 817 * Get the actual dynamic linker pathname from the executable if 818 * possible. (It should always be possible.) That ensures that 819 * gdb will find the right dynamic linker even if a non-standard 820 * one is being used. 821 */ 822 if (obj_main->interp != NULL && 823 strcmp(obj_main->interp, obj_rtld.path) != 0) { 824 free(obj_rtld.path); 825 obj_rtld.path = xstrdup(obj_main->interp); 826 __progname = obj_rtld.path; 827 } 828 #endif 829 830 if (!digest_dynamic(obj_main, 0)) 831 rtld_die(); 832 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", 833 obj_main->path, obj_main->valid_hash_sysv, obj_main->valid_hash_gnu, 834 obj_main->dynsymcount); 835 836 linkmap_add(obj_main); 837 linkmap_add(&obj_rtld); 838 839 /* Link the main program into the list of objects. */ 840 TAILQ_INSERT_HEAD(&obj_list, obj_main, next); 841 obj_count++; 842 obj_loads++; 843 844 /* Initialize a fake symbol for resolving undefined weak references. */ 845 sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE); 846 sym_zero.st_shndx = SHN_UNDEF; 847 sym_zero.st_value = -(uintptr_t)obj_main->relocbase; 848 849 if (!libmap_disable) 850 libmap_disable = (bool)lm_init(libmap_override); 851 852 if (aux_info[AT_KPRELOAD] != NULL && 853 aux_info[AT_KPRELOAD]->a_un.a_ptr != NULL) { 854 dbg("loading kernel vdso"); 855 if (load_kpreload(aux_info[AT_KPRELOAD]->a_un.a_ptr) == -1) 856 rtld_die(); 857 } 858 859 dbg("loading LD_PRELOAD_FDS libraries"); 860 if (load_preload_objects(ld_preload_fds, true) == -1) 861 rtld_die(); 862 863 dbg("loading LD_PRELOAD libraries"); 864 if (load_preload_objects(ld_preload, false) == -1) 865 rtld_die(); 866 preload_tail = globallist_curr(TAILQ_LAST(&obj_list, obj_entry_q)); 867 868 dbg("loading needed objects"); 869 if (load_needed_objects(obj_main, ld_tracing != NULL ? RTLD_LO_TRACE : 870 0) == -1) 871 rtld_die(); 872 873 /* Make a list of all objects loaded at startup. */ 874 last_interposer = obj_main; 875 TAILQ_FOREACH(obj, &obj_list, next) { 876 if (obj->marker) 877 continue; 878 if (obj->z_interpose && obj != obj_main) { 879 objlist_put_after(&list_main, last_interposer, obj); 880 last_interposer = obj; 881 } else { 882 objlist_push_tail(&list_main, obj); 883 } 884 obj->refcount++; 885 } 886 887 dbg("checking for required versions"); 888 if (rtld_verify_versions(&list_main) == -1 && !ld_tracing) 889 rtld_die(); 890 891 if (ld_get_env_var(LD_SHOW_AUXV) != NULL) 892 dump_auxv(aux_info); 893 894 if (ld_tracing) { /* We're done */ 895 trace_loaded_objects(obj_main, true); 896 exit(0); 897 } 898 899 if (ld_get_env_var(LD_DUMP_REL_PRE) != NULL) { 900 dump_relocations(obj_main); 901 exit (0); 902 } 903 904 /* 905 * Processing tls relocations requires having the tls offsets 906 * initialized. Prepare offsets before starting initial 907 * relocation processing. 908 */ 909 dbg("initializing initial thread local storage offsets"); 910 STAILQ_FOREACH(entry, &list_main, link) { 911 /* 912 * Allocate all the initial objects out of the static TLS 913 * block even if they didn't ask for it. 914 */ 915 allocate_tls_offset(entry->obj); 916 } 917 918 if (relocate_objects(obj_main, 919 ld_bind_now != NULL && *ld_bind_now != '\0', 920 &obj_rtld, SYMLOOK_EARLY, NULL) == -1) 921 rtld_die(); 922 923 dbg("doing copy relocations"); 924 if (do_copy_relocations(obj_main) == -1) 925 rtld_die(); 926 927 if (ld_get_env_var(LD_DUMP_REL_POST) != NULL) { 928 dump_relocations(obj_main); 929 exit (0); 930 } 931 932 ifunc_init(aux); 933 934 /* 935 * Setup TLS for main thread. This must be done after the 936 * relocations are processed, since tls initialization section 937 * might be the subject for relocations. 938 */ 939 dbg("initializing initial thread local storage"); 940 allocate_initial_tls(globallist_curr(TAILQ_FIRST(&obj_list))); 941 942 dbg("initializing key program variables"); 943 set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : ""); 944 set_program_var("environ", env); 945 set_program_var("__elf_aux_vector", aux); 946 947 /* Make a list of init functions to call. */ 948 objlist_init(&initlist); 949 initlist_add_objects(globallist_curr(TAILQ_FIRST(&obj_list)), 950 preload_tail, &initlist); 951 952 r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */ 953 954 map_stacks_exec(NULL); 955 956 if (!obj_main->crt_no_init) { 957 /* 958 * Make sure we don't call the main program's init and fini 959 * functions for binaries linked with old crt1 which calls 960 * _init itself. 961 */ 962 obj_main->init = obj_main->fini = (Elf_Addr)NULL; 963 obj_main->preinit_array = obj_main->init_array = 964 obj_main->fini_array = (Elf_Addr)NULL; 965 } 966 967 if (direct_exec) { 968 /* Set osrel for direct-execed binary */ 969 mib[0] = CTL_KERN; 970 mib[1] = KERN_PROC; 971 mib[2] = KERN_PROC_OSREL; 972 mib[3] = getpid(); 973 osrel = obj_main->osrel; 974 sz = sizeof(old_osrel); 975 dbg("setting osrel to %d", osrel); 976 (void)sysctl(mib, 4, &old_osrel, &sz, &osrel, sizeof(osrel)); 977 } 978 979 wlock_acquire(rtld_bind_lock, &lockstate); 980 981 dbg("resolving ifuncs"); 982 if (initlist_objects_ifunc(&initlist, ld_bind_now != NULL && 983 *ld_bind_now != '\0', SYMLOOK_EARLY, &lockstate) == -1) 984 rtld_die(); 985 986 rtld_exit_ptr = rtld_exit; 987 if (obj_main->crt_no_init) 988 preinit_main(); 989 objlist_call_init(&initlist, &lockstate); 990 _r_debug_postinit(&obj_main->linkmap); 991 objlist_clear(&initlist); 992 dbg("loading filtees"); 993 TAILQ_FOREACH(obj, &obj_list, next) { 994 if (obj->marker) 995 continue; 996 if (ld_loadfltr || obj->z_loadfltr) 997 load_filtees(obj, 0, &lockstate); 998 } 999 1000 dbg("enforcing main obj relro"); 1001 if (obj_enforce_relro(obj_main) == -1) 1002 rtld_die(); 1003 1004 lock_release(rtld_bind_lock, &lockstate); 1005 1006 dbg("transferring control to program entry point = %p", obj_main->entry); 1007 1008 /* Return the exit procedure and the program entry point. */ 1009 *exit_proc = rtld_exit_ptr; 1010 *objp = obj_main; 1011 return ((func_ptr_type)obj_main->entry); 1012 } 1013 1014 void * 1015 rtld_resolve_ifunc(const Obj_Entry *obj, const Elf_Sym *def) 1016 { 1017 void *ptr; 1018 Elf_Addr target; 1019 1020 ptr = (void *)make_function_pointer(def, obj); 1021 target = call_ifunc_resolver(ptr); 1022 return ((void *)target); 1023 } 1024 1025 Elf_Addr 1026 _rtld_bind(Obj_Entry *obj, Elf_Size reloff) 1027 { 1028 const Elf_Rel *rel; 1029 const Elf_Sym *def; 1030 const Obj_Entry *defobj; 1031 Elf_Addr *where; 1032 Elf_Addr target; 1033 RtldLockState lockstate; 1034 1035 rlock_acquire(rtld_bind_lock, &lockstate); 1036 if (sigsetjmp(lockstate.env, 0) != 0) 1037 lock_upgrade(rtld_bind_lock, &lockstate); 1038 if (obj->pltrel) 1039 rel = (const Elf_Rel *)((const char *)obj->pltrel + reloff); 1040 else 1041 rel = (const Elf_Rel *)((const char *)obj->pltrela + reloff); 1042 1043 where = (Elf_Addr *)(obj->relocbase + rel->r_offset); 1044 def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, SYMLOOK_IN_PLT, 1045 NULL, &lockstate); 1046 if (def == NULL) 1047 rtld_die(); 1048 if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 1049 target = (Elf_Addr)rtld_resolve_ifunc(defobj, def); 1050 else 1051 target = (Elf_Addr)(defobj->relocbase + def->st_value); 1052 1053 dbg("\"%s\" in \"%s\" ==> %p in \"%s\"", 1054 defobj->strtab + def->st_name, 1055 obj->path == NULL ? NULL : basename(obj->path), 1056 (void *)target, 1057 defobj->path == NULL ? NULL : basename(defobj->path)); 1058 1059 /* 1060 * Write the new contents for the jmpslot. Note that depending on 1061 * architecture, the value which we need to return back to the 1062 * lazy binding trampoline may or may not be the target 1063 * address. The value returned from reloc_jmpslot() is the value 1064 * that the trampoline needs. 1065 */ 1066 target = reloc_jmpslot(where, target, defobj, obj, rel); 1067 lock_release(rtld_bind_lock, &lockstate); 1068 return (target); 1069 } 1070 1071 /* 1072 * Error reporting function. Use it like printf. If formats the message 1073 * into a buffer, and sets things up so that the next call to dlerror() 1074 * will return the message. 1075 */ 1076 void 1077 _rtld_error(const char *fmt, ...) 1078 { 1079 va_list ap; 1080 1081 va_start(ap, fmt); 1082 rtld_vsnprintf(lockinfo.dlerror_loc(), lockinfo.dlerror_loc_sz, 1083 fmt, ap); 1084 va_end(ap); 1085 *lockinfo.dlerror_seen() = 0; 1086 dbg("rtld_error: %s", lockinfo.dlerror_loc()); 1087 LD_UTRACE(UTRACE_RTLD_ERROR, NULL, NULL, 0, 0, lockinfo.dlerror_loc()); 1088 } 1089 1090 /* 1091 * Return a dynamically-allocated copy of the current error message, if any. 1092 */ 1093 static struct dlerror_save * 1094 errmsg_save(void) 1095 { 1096 struct dlerror_save *res; 1097 1098 res = xmalloc(sizeof(*res)); 1099 res->seen = *lockinfo.dlerror_seen(); 1100 if (res->seen == 0) 1101 res->msg = xstrdup(lockinfo.dlerror_loc()); 1102 return (res); 1103 } 1104 1105 /* 1106 * Restore the current error message from a copy which was previously saved 1107 * by errmsg_save(). The copy is freed. 1108 */ 1109 static void 1110 errmsg_restore(struct dlerror_save *saved_msg) 1111 { 1112 if (saved_msg == NULL || saved_msg->seen == 1) { 1113 *lockinfo.dlerror_seen() = 1; 1114 } else { 1115 *lockinfo.dlerror_seen() = 0; 1116 strlcpy(lockinfo.dlerror_loc(), saved_msg->msg, 1117 lockinfo.dlerror_loc_sz); 1118 free(saved_msg->msg); 1119 } 1120 free(saved_msg); 1121 } 1122 1123 static const char * 1124 basename(const char *name) 1125 { 1126 const char *p; 1127 1128 p = strrchr(name, '/'); 1129 return (p != NULL ? p + 1 : name); 1130 } 1131 1132 static struct utsname uts; 1133 1134 static char * 1135 origin_subst_one(Obj_Entry *obj, char *real, const char *kw, 1136 const char *subst, bool may_free) 1137 { 1138 char *p, *p1, *res, *resp; 1139 int subst_len, kw_len, subst_count, old_len, new_len; 1140 1141 kw_len = strlen(kw); 1142 1143 /* 1144 * First, count the number of the keyword occurrences, to 1145 * preallocate the final string. 1146 */ 1147 for (p = real, subst_count = 0;; p = p1 + kw_len, subst_count++) { 1148 p1 = strstr(p, kw); 1149 if (p1 == NULL) 1150 break; 1151 } 1152 1153 /* 1154 * If the keyword is not found, just return. 1155 * 1156 * Return non-substituted string if resolution failed. We 1157 * cannot do anything more reasonable, the failure mode of the 1158 * caller is unresolved library anyway. 1159 */ 1160 if (subst_count == 0 || (obj != NULL && !obj_resolve_origin(obj))) 1161 return (may_free ? real : xstrdup(real)); 1162 if (obj != NULL) 1163 subst = obj->origin_path; 1164 1165 /* 1166 * There is indeed something to substitute. Calculate the 1167 * length of the resulting string, and allocate it. 1168 */ 1169 subst_len = strlen(subst); 1170 old_len = strlen(real); 1171 new_len = old_len + (subst_len - kw_len) * subst_count; 1172 res = xmalloc(new_len + 1); 1173 1174 /* 1175 * Now, execute the substitution loop. 1176 */ 1177 for (p = real, resp = res, *resp = '\0';;) { 1178 p1 = strstr(p, kw); 1179 if (p1 != NULL) { 1180 /* Copy the prefix before keyword. */ 1181 memcpy(resp, p, p1 - p); 1182 resp += p1 - p; 1183 /* Keyword replacement. */ 1184 memcpy(resp, subst, subst_len); 1185 resp += subst_len; 1186 *resp = '\0'; 1187 p = p1 + kw_len; 1188 } else 1189 break; 1190 } 1191 1192 /* Copy to the end of string and finish. */ 1193 strcat(resp, p); 1194 if (may_free) 1195 free(real); 1196 return (res); 1197 } 1198 1199 static const struct { 1200 const char *kw; 1201 bool pass_obj; 1202 const char *subst; 1203 } tokens[] = { 1204 { .kw = "$ORIGIN", .pass_obj = true, .subst = NULL }, 1205 { .kw = "${ORIGIN}", .pass_obj = true, .subst = NULL }, 1206 { .kw = "$OSNAME", .pass_obj = false, .subst = uts.sysname }, 1207 { .kw = "${OSNAME}", .pass_obj = false, .subst = uts.sysname }, 1208 { .kw = "$OSREL", .pass_obj = false, .subst = uts.release }, 1209 { .kw = "${OSREL}", .pass_obj = false, .subst = uts.release }, 1210 { .kw = "$PLATFORM", .pass_obj = false, .subst = uts.machine }, 1211 { .kw = "${PLATFORM}", .pass_obj = false, .subst = uts.machine }, 1212 { .kw = "$LIB", .pass_obj = false, .subst = TOKEN_LIB }, 1213 { .kw = "${LIB}", .pass_obj = false, .subst = TOKEN_LIB }, 1214 }; 1215 1216 static char * 1217 origin_subst(Obj_Entry *obj, const char *real) 1218 { 1219 char *res; 1220 int i; 1221 1222 if (obj == NULL || !trust) 1223 return (xstrdup(real)); 1224 if (uts.sysname[0] == '\0') { 1225 if (uname(&uts) != 0) { 1226 _rtld_error("utsname failed: %d", errno); 1227 return (NULL); 1228 } 1229 } 1230 1231 /* __DECONST is safe here since without may_free real is unchanged */ 1232 res = __DECONST(char *, real); 1233 for (i = 0; i < (int)nitems(tokens); i++) { 1234 res = origin_subst_one(tokens[i].pass_obj ? obj : NULL, 1235 res, tokens[i].kw, tokens[i].subst, i != 0); 1236 } 1237 return (res); 1238 } 1239 1240 void 1241 rtld_die(void) 1242 { 1243 const char *msg = dlerror(); 1244 1245 if (msg == NULL) 1246 msg = "Fatal error"; 1247 rtld_fdputstr(STDERR_FILENO, _BASENAME_RTLD ": "); 1248 rtld_fdputstr(STDERR_FILENO, msg); 1249 rtld_fdputchar(STDERR_FILENO, '\n'); 1250 _exit(1); 1251 } 1252 1253 /* 1254 * Process a shared object's DYNAMIC section, and save the important 1255 * information in its Obj_Entry structure. 1256 */ 1257 static void 1258 digest_dynamic1(Obj_Entry *obj, int early, const Elf_Dyn **dyn_rpath, 1259 const Elf_Dyn **dyn_soname, const Elf_Dyn **dyn_runpath) 1260 { 1261 const Elf_Dyn *dynp; 1262 Needed_Entry **needed_tail = &obj->needed; 1263 Needed_Entry **needed_filtees_tail = &obj->needed_filtees; 1264 Needed_Entry **needed_aux_filtees_tail = &obj->needed_aux_filtees; 1265 const Elf_Hashelt *hashtab; 1266 const Elf32_Word *hashval; 1267 Elf32_Word bkt, nmaskwords; 1268 int bloom_size32; 1269 int plttype = DT_REL; 1270 1271 *dyn_rpath = NULL; 1272 *dyn_soname = NULL; 1273 *dyn_runpath = NULL; 1274 1275 obj->bind_now = false; 1276 dynp = obj->dynamic; 1277 if (dynp == NULL) 1278 return; 1279 for (; dynp->d_tag != DT_NULL; dynp++) { 1280 switch (dynp->d_tag) { 1281 1282 case DT_REL: 1283 obj->rel = (const Elf_Rel *)(obj->relocbase + dynp->d_un.d_ptr); 1284 break; 1285 1286 case DT_RELSZ: 1287 obj->relsize = dynp->d_un.d_val; 1288 break; 1289 1290 case DT_RELENT: 1291 assert(dynp->d_un.d_val == sizeof(Elf_Rel)); 1292 break; 1293 1294 case DT_JMPREL: 1295 obj->pltrel = (const Elf_Rel *) 1296 (obj->relocbase + dynp->d_un.d_ptr); 1297 break; 1298 1299 case DT_PLTRELSZ: 1300 obj->pltrelsize = dynp->d_un.d_val; 1301 break; 1302 1303 case DT_RELA: 1304 obj->rela = (const Elf_Rela *)(obj->relocbase + dynp->d_un.d_ptr); 1305 break; 1306 1307 case DT_RELASZ: 1308 obj->relasize = dynp->d_un.d_val; 1309 break; 1310 1311 case DT_RELAENT: 1312 assert(dynp->d_un.d_val == sizeof(Elf_Rela)); 1313 break; 1314 1315 case DT_RELR: 1316 obj->relr = (const Elf_Relr *)(obj->relocbase + dynp->d_un.d_ptr); 1317 break; 1318 1319 case DT_RELRSZ: 1320 obj->relrsize = dynp->d_un.d_val; 1321 break; 1322 1323 case DT_RELRENT: 1324 assert(dynp->d_un.d_val == sizeof(Elf_Relr)); 1325 break; 1326 1327 case DT_PLTREL: 1328 plttype = dynp->d_un.d_val; 1329 assert(dynp->d_un.d_val == DT_REL || plttype == DT_RELA); 1330 break; 1331 1332 case DT_SYMTAB: 1333 obj->symtab = (const Elf_Sym *) 1334 (obj->relocbase + dynp->d_un.d_ptr); 1335 break; 1336 1337 case DT_SYMENT: 1338 assert(dynp->d_un.d_val == sizeof(Elf_Sym)); 1339 break; 1340 1341 case DT_STRTAB: 1342 obj->strtab = (const char *)(obj->relocbase + dynp->d_un.d_ptr); 1343 break; 1344 1345 case DT_STRSZ: 1346 obj->strsize = dynp->d_un.d_val; 1347 break; 1348 1349 case DT_VERNEED: 1350 obj->verneed = (const Elf_Verneed *)(obj->relocbase + 1351 dynp->d_un.d_val); 1352 break; 1353 1354 case DT_VERNEEDNUM: 1355 obj->verneednum = dynp->d_un.d_val; 1356 break; 1357 1358 case DT_VERDEF: 1359 obj->verdef = (const Elf_Verdef *)(obj->relocbase + 1360 dynp->d_un.d_val); 1361 break; 1362 1363 case DT_VERDEFNUM: 1364 obj->verdefnum = dynp->d_un.d_val; 1365 break; 1366 1367 case DT_VERSYM: 1368 obj->versyms = (const Elf_Versym *)(obj->relocbase + 1369 dynp->d_un.d_val); 1370 break; 1371 1372 case DT_HASH: 1373 { 1374 hashtab = (const Elf_Hashelt *)(obj->relocbase + 1375 dynp->d_un.d_ptr); 1376 obj->nbuckets = hashtab[0]; 1377 obj->nchains = hashtab[1]; 1378 obj->buckets = hashtab + 2; 1379 obj->chains = obj->buckets + obj->nbuckets; 1380 obj->valid_hash_sysv = obj->nbuckets > 0 && obj->nchains > 0 && 1381 obj->buckets != NULL; 1382 } 1383 break; 1384 1385 case DT_GNU_HASH: 1386 { 1387 hashtab = (const Elf_Hashelt *)(obj->relocbase + 1388 dynp->d_un.d_ptr); 1389 obj->nbuckets_gnu = hashtab[0]; 1390 obj->symndx_gnu = hashtab[1]; 1391 nmaskwords = hashtab[2]; 1392 bloom_size32 = (__ELF_WORD_SIZE / 32) * nmaskwords; 1393 obj->maskwords_bm_gnu = nmaskwords - 1; 1394 obj->shift2_gnu = hashtab[3]; 1395 obj->bloom_gnu = (const Elf_Addr *)(hashtab + 4); 1396 obj->buckets_gnu = hashtab + 4 + bloom_size32; 1397 obj->chain_zero_gnu = obj->buckets_gnu + obj->nbuckets_gnu - 1398 obj->symndx_gnu; 1399 /* Number of bitmask words is required to be power of 2 */ 1400 obj->valid_hash_gnu = powerof2(nmaskwords) && 1401 obj->nbuckets_gnu > 0 && obj->buckets_gnu != NULL; 1402 } 1403 break; 1404 1405 case DT_NEEDED: 1406 if (!obj->rtld) { 1407 Needed_Entry *nep = NEW(Needed_Entry); 1408 nep->name = dynp->d_un.d_val; 1409 nep->obj = NULL; 1410 nep->next = NULL; 1411 1412 *needed_tail = nep; 1413 needed_tail = &nep->next; 1414 } 1415 break; 1416 1417 case DT_FILTER: 1418 if (!obj->rtld) { 1419 Needed_Entry *nep = NEW(Needed_Entry); 1420 nep->name = dynp->d_un.d_val; 1421 nep->obj = NULL; 1422 nep->next = NULL; 1423 1424 *needed_filtees_tail = nep; 1425 needed_filtees_tail = &nep->next; 1426 1427 if (obj->linkmap.l_refname == NULL) 1428 obj->linkmap.l_refname = (char *)dynp->d_un.d_val; 1429 } 1430 break; 1431 1432 case DT_AUXILIARY: 1433 if (!obj->rtld) { 1434 Needed_Entry *nep = NEW(Needed_Entry); 1435 nep->name = dynp->d_un.d_val; 1436 nep->obj = NULL; 1437 nep->next = NULL; 1438 1439 *needed_aux_filtees_tail = nep; 1440 needed_aux_filtees_tail = &nep->next; 1441 } 1442 break; 1443 1444 case DT_PLTGOT: 1445 obj->pltgot = (Elf_Addr *)(obj->relocbase + dynp->d_un.d_ptr); 1446 break; 1447 1448 case DT_TEXTREL: 1449 obj->textrel = true; 1450 break; 1451 1452 case DT_SYMBOLIC: 1453 obj->symbolic = true; 1454 break; 1455 1456 case DT_RPATH: 1457 /* 1458 * We have to wait until later to process this, because we 1459 * might not have gotten the address of the string table yet. 1460 */ 1461 *dyn_rpath = dynp; 1462 break; 1463 1464 case DT_SONAME: 1465 *dyn_soname = dynp; 1466 break; 1467 1468 case DT_RUNPATH: 1469 *dyn_runpath = dynp; 1470 break; 1471 1472 case DT_INIT: 1473 obj->init = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1474 break; 1475 1476 case DT_PREINIT_ARRAY: 1477 obj->preinit_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1478 break; 1479 1480 case DT_PREINIT_ARRAYSZ: 1481 obj->preinit_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1482 break; 1483 1484 case DT_INIT_ARRAY: 1485 obj->init_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1486 break; 1487 1488 case DT_INIT_ARRAYSZ: 1489 obj->init_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1490 break; 1491 1492 case DT_FINI: 1493 obj->fini = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1494 break; 1495 1496 case DT_FINI_ARRAY: 1497 obj->fini_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1498 break; 1499 1500 case DT_FINI_ARRAYSZ: 1501 obj->fini_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1502 break; 1503 1504 case DT_DEBUG: 1505 if (!early) 1506 dbg("Filling in DT_DEBUG entry"); 1507 (__DECONST(Elf_Dyn *, dynp))->d_un.d_ptr = (Elf_Addr)&r_debug; 1508 break; 1509 1510 case DT_FLAGS: 1511 if (dynp->d_un.d_val & DF_ORIGIN) 1512 obj->z_origin = true; 1513 if (dynp->d_un.d_val & DF_SYMBOLIC) 1514 obj->symbolic = true; 1515 if (dynp->d_un.d_val & DF_TEXTREL) 1516 obj->textrel = true; 1517 if (dynp->d_un.d_val & DF_BIND_NOW) 1518 obj->bind_now = true; 1519 if (dynp->d_un.d_val & DF_STATIC_TLS) 1520 obj->static_tls = true; 1521 break; 1522 1523 case DT_FLAGS_1: 1524 if (dynp->d_un.d_val & DF_1_NOOPEN) 1525 obj->z_noopen = true; 1526 if (dynp->d_un.d_val & DF_1_ORIGIN) 1527 obj->z_origin = true; 1528 if (dynp->d_un.d_val & DF_1_GLOBAL) 1529 obj->z_global = true; 1530 if (dynp->d_un.d_val & DF_1_BIND_NOW) 1531 obj->bind_now = true; 1532 if (dynp->d_un.d_val & DF_1_NODELETE) 1533 obj->z_nodelete = true; 1534 if (dynp->d_un.d_val & DF_1_LOADFLTR) 1535 obj->z_loadfltr = true; 1536 if (dynp->d_un.d_val & DF_1_INTERPOSE) 1537 obj->z_interpose = true; 1538 if (dynp->d_un.d_val & DF_1_NODEFLIB) 1539 obj->z_nodeflib = true; 1540 if (dynp->d_un.d_val & DF_1_PIE) 1541 obj->z_pie = true; 1542 break; 1543 1544 default: 1545 if (arch_digest_dynamic(obj, dynp)) 1546 break; 1547 1548 if (!early) { 1549 dbg("Ignoring d_tag %ld = %#lx", (long)dynp->d_tag, 1550 (long)dynp->d_tag); 1551 } 1552 break; 1553 } 1554 } 1555 1556 obj->traced = false; 1557 1558 if (plttype == DT_RELA) { 1559 obj->pltrela = (const Elf_Rela *) obj->pltrel; 1560 obj->pltrel = NULL; 1561 obj->pltrelasize = obj->pltrelsize; 1562 obj->pltrelsize = 0; 1563 } 1564 1565 /* Determine size of dynsym table (equal to nchains of sysv hash) */ 1566 if (obj->valid_hash_sysv) 1567 obj->dynsymcount = obj->nchains; 1568 else if (obj->valid_hash_gnu) { 1569 obj->dynsymcount = 0; 1570 for (bkt = 0; bkt < obj->nbuckets_gnu; bkt++) { 1571 if (obj->buckets_gnu[bkt] == 0) 1572 continue; 1573 hashval = &obj->chain_zero_gnu[obj->buckets_gnu[bkt]]; 1574 do 1575 obj->dynsymcount++; 1576 while ((*hashval++ & 1u) == 0); 1577 } 1578 obj->dynsymcount += obj->symndx_gnu; 1579 } 1580 1581 if (obj->linkmap.l_refname != NULL) 1582 obj->linkmap.l_refname = obj->strtab + (unsigned long)obj-> 1583 linkmap.l_refname; 1584 } 1585 1586 static bool 1587 obj_resolve_origin(Obj_Entry *obj) 1588 { 1589 1590 if (obj->origin_path != NULL) 1591 return (true); 1592 obj->origin_path = xmalloc(PATH_MAX); 1593 return (rtld_dirname_abs(obj->path, obj->origin_path) != -1); 1594 } 1595 1596 static bool 1597 digest_dynamic2(Obj_Entry *obj, const Elf_Dyn *dyn_rpath, 1598 const Elf_Dyn *dyn_soname, const Elf_Dyn *dyn_runpath) 1599 { 1600 1601 if (obj->z_origin && !obj_resolve_origin(obj)) 1602 return (false); 1603 1604 if (dyn_runpath != NULL) { 1605 obj->runpath = (const char *)obj->strtab + dyn_runpath->d_un.d_val; 1606 obj->runpath = origin_subst(obj, obj->runpath); 1607 } else if (dyn_rpath != NULL) { 1608 obj->rpath = (const char *)obj->strtab + dyn_rpath->d_un.d_val; 1609 obj->rpath = origin_subst(obj, obj->rpath); 1610 } 1611 if (dyn_soname != NULL) 1612 object_add_name(obj, obj->strtab + dyn_soname->d_un.d_val); 1613 return (true); 1614 } 1615 1616 static bool 1617 digest_dynamic(Obj_Entry *obj, int early) 1618 { 1619 const Elf_Dyn *dyn_rpath; 1620 const Elf_Dyn *dyn_soname; 1621 const Elf_Dyn *dyn_runpath; 1622 1623 digest_dynamic1(obj, early, &dyn_rpath, &dyn_soname, &dyn_runpath); 1624 return (digest_dynamic2(obj, dyn_rpath, dyn_soname, dyn_runpath)); 1625 } 1626 1627 /* 1628 * Process a shared object's program header. This is used only for the 1629 * main program, when the kernel has already loaded the main program 1630 * into memory before calling the dynamic linker. It creates and 1631 * returns an Obj_Entry structure. 1632 */ 1633 static Obj_Entry * 1634 digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path) 1635 { 1636 Obj_Entry *obj; 1637 const Elf_Phdr *phlimit = phdr + phnum; 1638 const Elf_Phdr *ph; 1639 Elf_Addr note_start, note_end; 1640 int nsegs = 0; 1641 1642 obj = obj_new(); 1643 for (ph = phdr; ph < phlimit; ph++) { 1644 if (ph->p_type != PT_PHDR) 1645 continue; 1646 1647 obj->phdr = phdr; 1648 obj->phsize = ph->p_memsz; 1649 obj->relocbase = __DECONST(char *, phdr) - ph->p_vaddr; 1650 break; 1651 } 1652 1653 obj->stack_flags = PF_X | PF_R | PF_W; 1654 1655 for (ph = phdr; ph < phlimit; ph++) { 1656 switch (ph->p_type) { 1657 1658 case PT_INTERP: 1659 obj->interp = (const char *)(ph->p_vaddr + obj->relocbase); 1660 break; 1661 1662 case PT_LOAD: 1663 if (nsegs == 0) { /* First load segment */ 1664 obj->vaddrbase = rtld_trunc_page(ph->p_vaddr); 1665 obj->mapbase = obj->vaddrbase + obj->relocbase; 1666 } else { /* Last load segment */ 1667 obj->mapsize = rtld_round_page(ph->p_vaddr + ph->p_memsz) - 1668 obj->vaddrbase; 1669 } 1670 nsegs++; 1671 break; 1672 1673 case PT_DYNAMIC: 1674 obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + obj->relocbase); 1675 break; 1676 1677 case PT_TLS: 1678 obj->tlsindex = 1; 1679 obj->tlssize = ph->p_memsz; 1680 obj->tlsalign = ph->p_align; 1681 obj->tlsinitsize = ph->p_filesz; 1682 obj->tlsinit = (void*)(ph->p_vaddr + obj->relocbase); 1683 obj->tlspoffset = ph->p_offset; 1684 break; 1685 1686 case PT_GNU_STACK: 1687 obj->stack_flags = ph->p_flags; 1688 break; 1689 1690 case PT_GNU_RELRO: 1691 obj->relro_page = obj->relocbase + rtld_trunc_page(ph->p_vaddr); 1692 obj->relro_size = rtld_trunc_page(ph->p_vaddr + ph->p_memsz) - 1693 rtld_trunc_page(ph->p_vaddr); 1694 break; 1695 1696 case PT_NOTE: 1697 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; 1698 note_end = note_start + ph->p_filesz; 1699 digest_notes(obj, note_start, note_end); 1700 break; 1701 } 1702 } 1703 if (nsegs < 1) { 1704 _rtld_error("%s: too few PT_LOAD segments", path); 1705 return (NULL); 1706 } 1707 1708 obj->entry = entry; 1709 return (obj); 1710 } 1711 1712 void 1713 digest_notes(Obj_Entry *obj, Elf_Addr note_start, Elf_Addr note_end) 1714 { 1715 const Elf_Note *note; 1716 const char *note_name; 1717 uintptr_t p; 1718 1719 for (note = (const Elf_Note *)note_start; (Elf_Addr)note < note_end; 1720 note = (const Elf_Note *)((const char *)(note + 1) + 1721 roundup2(note->n_namesz, sizeof(Elf32_Addr)) + 1722 roundup2(note->n_descsz, sizeof(Elf32_Addr)))) { 1723 if (arch_digest_note(obj, note)) 1724 continue; 1725 1726 if (note->n_namesz != sizeof(NOTE_FREEBSD_VENDOR) || 1727 note->n_descsz != sizeof(int32_t)) 1728 continue; 1729 if (note->n_type != NT_FREEBSD_ABI_TAG && 1730 note->n_type != NT_FREEBSD_FEATURE_CTL && 1731 note->n_type != NT_FREEBSD_NOINIT_TAG) 1732 continue; 1733 note_name = (const char *)(note + 1); 1734 if (strncmp(NOTE_FREEBSD_VENDOR, note_name, 1735 sizeof(NOTE_FREEBSD_VENDOR)) != 0) 1736 continue; 1737 switch (note->n_type) { 1738 case NT_FREEBSD_ABI_TAG: 1739 /* FreeBSD osrel note */ 1740 p = (uintptr_t)(note + 1); 1741 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1742 obj->osrel = *(const int32_t *)(p); 1743 dbg("note osrel %d", obj->osrel); 1744 break; 1745 case NT_FREEBSD_FEATURE_CTL: 1746 /* FreeBSD ABI feature control note */ 1747 p = (uintptr_t)(note + 1); 1748 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1749 obj->fctl0 = *(const uint32_t *)(p); 1750 dbg("note fctl0 %#x", obj->fctl0); 1751 break; 1752 case NT_FREEBSD_NOINIT_TAG: 1753 /* FreeBSD 'crt does not call init' note */ 1754 obj->crt_no_init = true; 1755 dbg("note crt_no_init"); 1756 break; 1757 } 1758 } 1759 } 1760 1761 static Obj_Entry * 1762 dlcheck(void *handle) 1763 { 1764 Obj_Entry *obj; 1765 1766 TAILQ_FOREACH(obj, &obj_list, next) { 1767 if (obj == (Obj_Entry *) handle) 1768 break; 1769 } 1770 1771 if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) { 1772 _rtld_error("Invalid shared object handle %p", handle); 1773 return (NULL); 1774 } 1775 return (obj); 1776 } 1777 1778 /* 1779 * If the given object is already in the donelist, return true. Otherwise 1780 * add the object to the list and return false. 1781 */ 1782 static bool 1783 donelist_check(DoneList *dlp, const Obj_Entry *obj) 1784 { 1785 unsigned int i; 1786 1787 for (i = 0; i < dlp->num_used; i++) 1788 if (dlp->objs[i] == obj) 1789 return (true); 1790 /* 1791 * Our donelist allocation should always be sufficient. But if 1792 * our threads locking isn't working properly, more shared objects 1793 * could have been loaded since we allocated the list. That should 1794 * never happen, but we'll handle it properly just in case it does. 1795 */ 1796 if (dlp->num_used < dlp->num_alloc) 1797 dlp->objs[dlp->num_used++] = obj; 1798 return (false); 1799 } 1800 1801 /* 1802 * SysV hash function for symbol table lookup. It is a slightly optimized 1803 * version of the hash specified by the System V ABI. 1804 */ 1805 Elf32_Word 1806 elf_hash(const char *name) 1807 { 1808 const unsigned char *p = (const unsigned char *)name; 1809 Elf32_Word h = 0; 1810 1811 while (*p != '\0') { 1812 h = (h << 4) + *p++; 1813 h ^= (h >> 24) & 0xf0; 1814 } 1815 return (h & 0x0fffffff); 1816 } 1817 1818 /* 1819 * The GNU hash function is the Daniel J. Bernstein hash clipped to 32 bits 1820 * unsigned in case it's implemented with a wider type. 1821 */ 1822 static uint32_t 1823 gnu_hash(const char *s) 1824 { 1825 uint32_t h; 1826 unsigned char c; 1827 1828 h = 5381; 1829 for (c = *s; c != '\0'; c = *++s) 1830 h = h * 33 + c; 1831 return (h & 0xffffffff); 1832 } 1833 1834 1835 /* 1836 * Find the library with the given name, and return its full pathname. 1837 * The returned string is dynamically allocated. Generates an error 1838 * message and returns NULL if the library cannot be found. 1839 * 1840 * If the second argument is non-NULL, then it refers to an already- 1841 * loaded shared object, whose library search path will be searched. 1842 * 1843 * If a library is successfully located via LD_LIBRARY_PATH_FDS, its 1844 * descriptor (which is close-on-exec) will be passed out via the third 1845 * argument. 1846 * 1847 * The search order is: 1848 * DT_RPATH in the referencing file _unless_ DT_RUNPATH is present (1) 1849 * DT_RPATH of the main object if DSO without defined DT_RUNPATH (1) 1850 * LD_LIBRARY_PATH 1851 * DT_RUNPATH in the referencing file 1852 * ldconfig hints (if -z nodefaultlib, filter out default library directories 1853 * from list) 1854 * /lib:/usr/lib _unless_ the referencing file is linked with -z nodefaultlib 1855 * 1856 * (1) Handled in digest_dynamic2 - rpath left NULL if runpath defined. 1857 */ 1858 static char * 1859 find_library(const char *xname, const Obj_Entry *refobj, int *fdp) 1860 { 1861 char *pathname, *refobj_path; 1862 const char *name; 1863 bool nodeflib, objgiven; 1864 1865 objgiven = refobj != NULL; 1866 1867 if (libmap_disable || !objgiven || 1868 (name = lm_find(refobj->path, xname)) == NULL) 1869 name = xname; 1870 1871 if (strchr(name, '/') != NULL) { /* Hard coded pathname */ 1872 if (name[0] != '/' && !trust) { 1873 _rtld_error("Absolute pathname required " 1874 "for shared object \"%s\"", name); 1875 return (NULL); 1876 } 1877 return (origin_subst(__DECONST(Obj_Entry *, refobj), 1878 __DECONST(char *, name))); 1879 } 1880 1881 dbg(" Searching for \"%s\"", name); 1882 refobj_path = objgiven ? refobj->path : NULL; 1883 1884 /* 1885 * If refobj->rpath != NULL, then refobj->runpath is NULL. Fall 1886 * back to pre-conforming behaviour if user requested so with 1887 * LD_LIBRARY_PATH_RPATH environment variable and ignore -z 1888 * nodeflib. 1889 */ 1890 if (objgiven && refobj->rpath != NULL && ld_library_path_rpath) { 1891 pathname = search_library_path(name, ld_library_path, 1892 refobj_path, fdp); 1893 if (pathname != NULL) 1894 return (pathname); 1895 if (refobj != NULL) { 1896 pathname = search_library_path(name, refobj->rpath, 1897 refobj_path, fdp); 1898 if (pathname != NULL) 1899 return (pathname); 1900 } 1901 pathname = search_library_pathfds(name, ld_library_dirs, fdp); 1902 if (pathname != NULL) 1903 return (pathname); 1904 pathname = search_library_path(name, gethints(false), 1905 refobj_path, fdp); 1906 if (pathname != NULL) 1907 return (pathname); 1908 pathname = search_library_path(name, ld_standard_library_path, 1909 refobj_path, fdp); 1910 if (pathname != NULL) 1911 return (pathname); 1912 } else { 1913 nodeflib = objgiven ? refobj->z_nodeflib : false; 1914 if (objgiven) { 1915 pathname = search_library_path(name, refobj->rpath, 1916 refobj->path, fdp); 1917 if (pathname != NULL) 1918 return (pathname); 1919 } 1920 if (objgiven && refobj->runpath == NULL && refobj != obj_main) { 1921 pathname = search_library_path(name, obj_main->rpath, 1922 refobj_path, fdp); 1923 if (pathname != NULL) 1924 return (pathname); 1925 } 1926 pathname = search_library_path(name, ld_library_path, 1927 refobj_path, fdp); 1928 if (pathname != NULL) 1929 return (pathname); 1930 if (objgiven) { 1931 pathname = search_library_path(name, refobj->runpath, 1932 refobj_path, fdp); 1933 if (pathname != NULL) 1934 return (pathname); 1935 } 1936 pathname = search_library_pathfds(name, ld_library_dirs, fdp); 1937 if (pathname != NULL) 1938 return (pathname); 1939 pathname = search_library_path(name, gethints(nodeflib), 1940 refobj_path, fdp); 1941 if (pathname != NULL) 1942 return (pathname); 1943 if (objgiven && !nodeflib) { 1944 pathname = search_library_path(name, 1945 ld_standard_library_path, refobj_path, fdp); 1946 if (pathname != NULL) 1947 return (pathname); 1948 } 1949 } 1950 1951 if (objgiven && refobj->path != NULL) { 1952 _rtld_error("Shared object \"%s\" not found, " 1953 "required by \"%s\"", name, basename(refobj->path)); 1954 } else { 1955 _rtld_error("Shared object \"%s\" not found", name); 1956 } 1957 return (NULL); 1958 } 1959 1960 /* 1961 * Given a symbol number in a referencing object, find the corresponding 1962 * definition of the symbol. Returns a pointer to the symbol, or NULL if 1963 * no definition was found. Returns a pointer to the Obj_Entry of the 1964 * defining object via the reference parameter DEFOBJ_OUT. 1965 */ 1966 const Elf_Sym * 1967 find_symdef(unsigned long symnum, const Obj_Entry *refobj, 1968 const Obj_Entry **defobj_out, int flags, SymCache *cache, 1969 RtldLockState *lockstate) 1970 { 1971 const Elf_Sym *ref; 1972 const Elf_Sym *def; 1973 const Obj_Entry *defobj; 1974 const Ver_Entry *ve; 1975 SymLook req; 1976 const char *name; 1977 int res; 1978 1979 /* 1980 * If we have already found this symbol, get the information from 1981 * the cache. 1982 */ 1983 if (symnum >= refobj->dynsymcount) 1984 return (NULL); /* Bad object */ 1985 if (cache != NULL && cache[symnum].sym != NULL) { 1986 *defobj_out = cache[symnum].obj; 1987 return (cache[symnum].sym); 1988 } 1989 1990 ref = refobj->symtab + symnum; 1991 name = refobj->strtab + ref->st_name; 1992 def = NULL; 1993 defobj = NULL; 1994 ve = NULL; 1995 1996 /* 1997 * We don't have to do a full scale lookup if the symbol is local. 1998 * We know it will bind to the instance in this load module; to 1999 * which we already have a pointer (ie ref). By not doing a lookup, 2000 * we not only improve performance, but it also avoids unresolvable 2001 * symbols when local symbols are not in the hash table. This has 2002 * been seen with the ia64 toolchain. 2003 */ 2004 if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) { 2005 if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) { 2006 _rtld_error("%s: Bogus symbol table entry %lu", refobj->path, 2007 symnum); 2008 } 2009 symlook_init(&req, name); 2010 req.flags = flags; 2011 ve = req.ventry = fetch_ventry(refobj, symnum); 2012 req.lockstate = lockstate; 2013 res = symlook_default(&req, refobj); 2014 if (res == 0) { 2015 def = req.sym_out; 2016 defobj = req.defobj_out; 2017 } 2018 } else { 2019 def = ref; 2020 defobj = refobj; 2021 } 2022 2023 /* 2024 * If we found no definition and the reference is weak, treat the 2025 * symbol as having the value zero. 2026 */ 2027 if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) { 2028 def = &sym_zero; 2029 defobj = obj_main; 2030 } 2031 2032 if (def != NULL) { 2033 *defobj_out = defobj; 2034 /* Record the information in the cache to avoid subsequent lookups. */ 2035 if (cache != NULL) { 2036 cache[symnum].sym = def; 2037 cache[symnum].obj = defobj; 2038 } 2039 } else { 2040 if (refobj != &obj_rtld) 2041 _rtld_error("%s: Undefined symbol \"%s%s%s\"", refobj->path, name, 2042 ve != NULL ? "@" : "", ve != NULL ? ve->name : ""); 2043 } 2044 return (def); 2045 } 2046 2047 /* Convert between native byte order and forced little resp. big endian. */ 2048 #define COND_SWAP(n) (is_le ? le32toh(n) : be32toh(n)) 2049 2050 /* 2051 * Return the search path from the ldconfig hints file, reading it if 2052 * necessary. If nostdlib is true, then the default search paths are 2053 * not added to result. 2054 * 2055 * Returns NULL if there are problems with the hints file, 2056 * or if the search path there is empty. 2057 */ 2058 static const char * 2059 gethints(bool nostdlib) 2060 { 2061 static char *filtered_path; 2062 static const char *hints; 2063 static struct elfhints_hdr hdr; 2064 struct fill_search_info_args sargs, hargs; 2065 struct dl_serinfo smeta, hmeta, *SLPinfo, *hintinfo; 2066 struct dl_serpath *SLPpath, *hintpath; 2067 char *p; 2068 struct stat hint_stat; 2069 unsigned int SLPndx, hintndx, fndx, fcount; 2070 int fd; 2071 size_t flen; 2072 uint32_t dl; 2073 uint32_t magic; /* Magic number */ 2074 uint32_t version; /* File version (1) */ 2075 uint32_t strtab; /* Offset of string table in file */ 2076 uint32_t dirlist; /* Offset of directory list in string table */ 2077 uint32_t dirlistlen; /* strlen(dirlist) */ 2078 bool is_le; /* Does the hints file use little endian */ 2079 bool skip; 2080 2081 /* First call, read the hints file */ 2082 if (hints == NULL) { 2083 /* Keep from trying again in case the hints file is bad. */ 2084 hints = ""; 2085 2086 if ((fd = open(ld_elf_hints_path, O_RDONLY | O_CLOEXEC)) == -1) { 2087 dbg("failed to open hints file \"%s\"", ld_elf_hints_path); 2088 return (NULL); 2089 } 2090 2091 /* 2092 * Check of hdr.dirlistlen value against type limit 2093 * intends to pacify static analyzers. Further 2094 * paranoia leads to checks that dirlist is fully 2095 * contained in the file range. 2096 */ 2097 if (read(fd, &hdr, sizeof hdr) != sizeof hdr) { 2098 dbg("failed to read %lu bytes from hints file \"%s\"", 2099 (u_long)sizeof hdr, ld_elf_hints_path); 2100 cleanup1: 2101 close(fd); 2102 hdr.dirlistlen = 0; 2103 return (NULL); 2104 } 2105 dbg("host byte-order: %s-endian", le32toh(1) == 1 ? "little" : "big"); 2106 dbg("hints file byte-order: %s-endian", 2107 hdr.magic == htole32(ELFHINTS_MAGIC) ? "little" : "big"); 2108 is_le = /*htole32(1) == 1 || */ hdr.magic == htole32(ELFHINTS_MAGIC); 2109 magic = COND_SWAP(hdr.magic); 2110 version = COND_SWAP(hdr.version); 2111 strtab = COND_SWAP(hdr.strtab); 2112 dirlist = COND_SWAP(hdr.dirlist); 2113 dirlistlen = COND_SWAP(hdr.dirlistlen); 2114 if (magic != ELFHINTS_MAGIC) { 2115 dbg("invalid magic number %#08x (expected: %#08x)", 2116 magic, ELFHINTS_MAGIC); 2117 goto cleanup1; 2118 } 2119 if (version != 1) { 2120 dbg("hints file version %d (expected: 1)", version); 2121 goto cleanup1; 2122 } 2123 if (dirlistlen > UINT_MAX / 2) { 2124 dbg("directory list is to long: %d > %d", 2125 dirlistlen, UINT_MAX / 2); 2126 goto cleanup1; 2127 } 2128 if (fstat(fd, &hint_stat) == -1) { 2129 dbg("failed to find length of hints file \"%s\"", 2130 ld_elf_hints_path); 2131 goto cleanup1; 2132 } 2133 dl = strtab; 2134 if (dl + dirlist < dl) { 2135 dbg("invalid string table position %d", dl); 2136 goto cleanup1; 2137 } 2138 dl += dirlist; 2139 if (dl + dirlistlen < dl) { 2140 dbg("invalid directory list offset %d", dirlist); 2141 goto cleanup1; 2142 } 2143 dl += dirlistlen; 2144 if (dl > hint_stat.st_size) { 2145 dbg("hints file \"%s\" is truncated (%d vs. %jd bytes)", 2146 ld_elf_hints_path, dl, (uintmax_t)hint_stat.st_size); 2147 goto cleanup1; 2148 } 2149 p = xmalloc(dirlistlen + 1); 2150 if (pread(fd, p, dirlistlen + 1, 2151 strtab + dirlist) != (ssize_t)dirlistlen + 1 || 2152 p[dirlistlen] != '\0') { 2153 free(p); 2154 dbg("failed to read %d bytes starting at %d from hints file \"%s\"", 2155 dirlistlen + 1, strtab + dirlist, ld_elf_hints_path); 2156 goto cleanup1; 2157 } 2158 hints = p; 2159 close(fd); 2160 } 2161 2162 /* 2163 * If caller agreed to receive list which includes the default 2164 * paths, we are done. Otherwise, if we still did not 2165 * calculated filtered result, do it now. 2166 */ 2167 if (!nostdlib) 2168 return (hints[0] != '\0' ? hints : NULL); 2169 if (filtered_path != NULL) 2170 goto filt_ret; 2171 2172 /* 2173 * Obtain the list of all configured search paths, and the 2174 * list of the default paths. 2175 * 2176 * First estimate the size of the results. 2177 */ 2178 smeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 2179 smeta.dls_cnt = 0; 2180 hmeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 2181 hmeta.dls_cnt = 0; 2182 2183 sargs.request = RTLD_DI_SERINFOSIZE; 2184 sargs.serinfo = &smeta; 2185 hargs.request = RTLD_DI_SERINFOSIZE; 2186 hargs.serinfo = &hmeta; 2187 2188 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 2189 &sargs); 2190 path_enumerate(hints, fill_search_info, NULL, &hargs); 2191 2192 SLPinfo = xmalloc(smeta.dls_size); 2193 hintinfo = xmalloc(hmeta.dls_size); 2194 2195 /* 2196 * Next fetch both sets of paths. 2197 */ 2198 sargs.request = RTLD_DI_SERINFO; 2199 sargs.serinfo = SLPinfo; 2200 sargs.serpath = &SLPinfo->dls_serpath[0]; 2201 sargs.strspace = (char *)&SLPinfo->dls_serpath[smeta.dls_cnt]; 2202 2203 hargs.request = RTLD_DI_SERINFO; 2204 hargs.serinfo = hintinfo; 2205 hargs.serpath = &hintinfo->dls_serpath[0]; 2206 hargs.strspace = (char *)&hintinfo->dls_serpath[hmeta.dls_cnt]; 2207 2208 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 2209 &sargs); 2210 path_enumerate(hints, fill_search_info, NULL, &hargs); 2211 2212 /* 2213 * Now calculate the difference between two sets, by excluding 2214 * standard paths from the full set. 2215 */ 2216 fndx = 0; 2217 fcount = 0; 2218 filtered_path = xmalloc(dirlistlen + 1); 2219 hintpath = &hintinfo->dls_serpath[0]; 2220 for (hintndx = 0; hintndx < hmeta.dls_cnt; hintndx++, hintpath++) { 2221 skip = false; 2222 SLPpath = &SLPinfo->dls_serpath[0]; 2223 /* 2224 * Check each standard path against current. 2225 */ 2226 for (SLPndx = 0; SLPndx < smeta.dls_cnt; SLPndx++, SLPpath++) { 2227 /* matched, skip the path */ 2228 if (!strcmp(hintpath->dls_name, SLPpath->dls_name)) { 2229 skip = true; 2230 break; 2231 } 2232 } 2233 if (skip) 2234 continue; 2235 /* 2236 * Not matched against any standard path, add the path 2237 * to result. Separate consequtive paths with ':'. 2238 */ 2239 if (fcount > 0) { 2240 filtered_path[fndx] = ':'; 2241 fndx++; 2242 } 2243 fcount++; 2244 flen = strlen(hintpath->dls_name); 2245 strncpy((filtered_path + fndx), hintpath->dls_name, flen); 2246 fndx += flen; 2247 } 2248 filtered_path[fndx] = '\0'; 2249 2250 free(SLPinfo); 2251 free(hintinfo); 2252 2253 filt_ret: 2254 return (filtered_path[0] != '\0' ? filtered_path : NULL); 2255 } 2256 2257 static void 2258 init_dag(Obj_Entry *root) 2259 { 2260 const Needed_Entry *needed; 2261 const Objlist_Entry *elm; 2262 DoneList donelist; 2263 2264 if (root->dag_inited) 2265 return; 2266 donelist_init(&donelist); 2267 2268 /* Root object belongs to own DAG. */ 2269 objlist_push_tail(&root->dldags, root); 2270 objlist_push_tail(&root->dagmembers, root); 2271 donelist_check(&donelist, root); 2272 2273 /* 2274 * Add dependencies of root object to DAG in breadth order 2275 * by exploiting the fact that each new object get added 2276 * to the tail of the dagmembers list. 2277 */ 2278 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2279 for (needed = elm->obj->needed; needed != NULL; needed = needed->next) { 2280 if (needed->obj == NULL || donelist_check(&donelist, needed->obj)) 2281 continue; 2282 objlist_push_tail(&needed->obj->dldags, root); 2283 objlist_push_tail(&root->dagmembers, needed->obj); 2284 } 2285 } 2286 root->dag_inited = true; 2287 } 2288 2289 static void 2290 init_marker(Obj_Entry *marker) 2291 { 2292 2293 bzero(marker, sizeof(*marker)); 2294 marker->marker = true; 2295 } 2296 2297 Obj_Entry * 2298 globallist_curr(const Obj_Entry *obj) 2299 { 2300 2301 for (;;) { 2302 if (obj == NULL) 2303 return (NULL); 2304 if (!obj->marker) 2305 return (__DECONST(Obj_Entry *, obj)); 2306 obj = TAILQ_PREV(obj, obj_entry_q, next); 2307 } 2308 } 2309 2310 Obj_Entry * 2311 globallist_next(const Obj_Entry *obj) 2312 { 2313 2314 for (;;) { 2315 obj = TAILQ_NEXT(obj, next); 2316 if (obj == NULL) 2317 return (NULL); 2318 if (!obj->marker) 2319 return (__DECONST(Obj_Entry *, obj)); 2320 } 2321 } 2322 2323 /* Prevent the object from being unmapped while the bind lock is dropped. */ 2324 static void 2325 hold_object(Obj_Entry *obj) 2326 { 2327 2328 obj->holdcount++; 2329 } 2330 2331 static void 2332 unhold_object(Obj_Entry *obj) 2333 { 2334 2335 assert(obj->holdcount > 0); 2336 if (--obj->holdcount == 0 && obj->unholdfree) 2337 release_object(obj); 2338 } 2339 2340 static void 2341 process_z(Obj_Entry *root) 2342 { 2343 const Objlist_Entry *elm; 2344 Obj_Entry *obj; 2345 2346 /* 2347 * Walk over object DAG and process every dependent object 2348 * that is marked as DF_1_NODELETE or DF_1_GLOBAL. They need 2349 * to grow their own DAG. 2350 * 2351 * For DF_1_GLOBAL, DAG is required for symbol lookups in 2352 * symlook_global() to work. 2353 * 2354 * For DF_1_NODELETE, the DAG should have its reference upped. 2355 */ 2356 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2357 obj = elm->obj; 2358 if (obj == NULL) 2359 continue; 2360 if (obj->z_nodelete && !obj->ref_nodel) { 2361 dbg("obj %s -z nodelete", obj->path); 2362 init_dag(obj); 2363 ref_dag(obj); 2364 obj->ref_nodel = true; 2365 } 2366 if (obj->z_global && objlist_find(&list_global, obj) == NULL) { 2367 dbg("obj %s -z global", obj->path); 2368 objlist_push_tail(&list_global, obj); 2369 init_dag(obj); 2370 } 2371 } 2372 } 2373 2374 static void 2375 parse_rtld_phdr(Obj_Entry *obj) 2376 { 2377 const Elf_Phdr *ph; 2378 Elf_Addr note_start, note_end; 2379 2380 obj->stack_flags = PF_X | PF_R | PF_W; 2381 for (ph = obj->phdr; (const char *)ph < (const char *)obj->phdr + 2382 obj->phsize; ph++) { 2383 switch (ph->p_type) { 2384 case PT_GNU_STACK: 2385 obj->stack_flags = ph->p_flags; 2386 break; 2387 case PT_GNU_RELRO: 2388 obj->relro_page = obj->relocbase + 2389 rtld_trunc_page(ph->p_vaddr); 2390 obj->relro_size = rtld_round_page(ph->p_memsz); 2391 break; 2392 case PT_NOTE: 2393 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; 2394 note_end = note_start + ph->p_filesz; 2395 digest_notes(obj, note_start, note_end); 2396 break; 2397 } 2398 } 2399 } 2400 2401 /* 2402 * Initialize the dynamic linker. The argument is the address at which 2403 * the dynamic linker has been mapped into memory. The primary task of 2404 * this function is to relocate the dynamic linker. 2405 */ 2406 static void 2407 init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info) 2408 { 2409 Obj_Entry objtmp; /* Temporary rtld object */ 2410 const Elf_Ehdr *ehdr; 2411 const Elf_Dyn *dyn_rpath; 2412 const Elf_Dyn *dyn_soname; 2413 const Elf_Dyn *dyn_runpath; 2414 2415 #ifdef RTLD_INIT_PAGESIZES_EARLY 2416 /* The page size is required by the dynamic memory allocator. */ 2417 init_pagesizes(aux_info); 2418 #endif 2419 2420 /* 2421 * Conjure up an Obj_Entry structure for the dynamic linker. 2422 * 2423 * The "path" member can't be initialized yet because string constants 2424 * cannot yet be accessed. Below we will set it correctly. 2425 */ 2426 memset(&objtmp, 0, sizeof(objtmp)); 2427 objtmp.path = NULL; 2428 objtmp.rtld = true; 2429 objtmp.mapbase = mapbase; 2430 #ifdef PIC 2431 objtmp.relocbase = mapbase; 2432 #endif 2433 2434 objtmp.dynamic = rtld_dynamic(&objtmp); 2435 digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname, &dyn_runpath); 2436 assert(objtmp.needed == NULL); 2437 assert(!objtmp.textrel); 2438 /* 2439 * Temporarily put the dynamic linker entry into the object list, so 2440 * that symbols can be found. 2441 */ 2442 relocate_objects(&objtmp, true, &objtmp, 0, NULL); 2443 2444 ehdr = (Elf_Ehdr *)mapbase; 2445 objtmp.phdr = (Elf_Phdr *)((char *)mapbase + ehdr->e_phoff); 2446 objtmp.phsize = ehdr->e_phnum * sizeof(objtmp.phdr[0]); 2447 2448 /* Initialize the object list. */ 2449 TAILQ_INIT(&obj_list); 2450 2451 /* Now that non-local variables can be accesses, copy out obj_rtld. */ 2452 memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld)); 2453 2454 #ifndef RTLD_INIT_PAGESIZES_EARLY 2455 /* The page size is required by the dynamic memory allocator. */ 2456 init_pagesizes(aux_info); 2457 #endif 2458 2459 if (aux_info[AT_OSRELDATE] != NULL) 2460 osreldate = aux_info[AT_OSRELDATE]->a_un.a_val; 2461 2462 digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname, dyn_runpath); 2463 2464 /* Replace the path with a dynamically allocated copy. */ 2465 obj_rtld.path = xstrdup(ld_path_rtld); 2466 2467 parse_rtld_phdr(&obj_rtld); 2468 if (obj_enforce_relro(&obj_rtld) == -1) 2469 rtld_die(); 2470 2471 r_debug.r_version = R_DEBUG_VERSION; 2472 r_debug.r_brk = r_debug_state; 2473 r_debug.r_state = RT_CONSISTENT; 2474 r_debug.r_ldbase = obj_rtld.relocbase; 2475 } 2476 2477 /* 2478 * Retrieve the array of supported page sizes. The kernel provides the page 2479 * sizes in increasing order. 2480 */ 2481 static void 2482 init_pagesizes(Elf_Auxinfo **aux_info) 2483 { 2484 static size_t psa[MAXPAGESIZES]; 2485 int mib[2]; 2486 size_t len, size; 2487 2488 if (aux_info[AT_PAGESIZES] != NULL && aux_info[AT_PAGESIZESLEN] != 2489 NULL) { 2490 size = aux_info[AT_PAGESIZESLEN]->a_un.a_val; 2491 pagesizes = aux_info[AT_PAGESIZES]->a_un.a_ptr; 2492 } else { 2493 len = 2; 2494 if (sysctlnametomib("hw.pagesizes", mib, &len) == 0) 2495 size = sizeof(psa); 2496 else { 2497 /* As a fallback, retrieve the base page size. */ 2498 size = sizeof(psa[0]); 2499 if (aux_info[AT_PAGESZ] != NULL) { 2500 psa[0] = aux_info[AT_PAGESZ]->a_un.a_val; 2501 goto psa_filled; 2502 } else { 2503 mib[0] = CTL_HW; 2504 mib[1] = HW_PAGESIZE; 2505 len = 2; 2506 } 2507 } 2508 if (sysctl(mib, len, psa, &size, NULL, 0) == -1) { 2509 _rtld_error("sysctl for hw.pagesize(s) failed"); 2510 rtld_die(); 2511 } 2512 psa_filled: 2513 pagesizes = psa; 2514 } 2515 npagesizes = size / sizeof(pagesizes[0]); 2516 /* Discard any invalid entries at the end of the array. */ 2517 while (npagesizes > 0 && pagesizes[npagesizes - 1] == 0) 2518 npagesizes--; 2519 2520 page_size = pagesizes[0]; 2521 } 2522 2523 /* 2524 * Add the init functions from a needed object list (and its recursive 2525 * needed objects) to "list". This is not used directly; it is a helper 2526 * function for initlist_add_objects(). The write lock must be held 2527 * when this function is called. 2528 */ 2529 static void 2530 initlist_add_neededs(Needed_Entry *needed, Objlist *list) 2531 { 2532 /* Recursively process the successor needed objects. */ 2533 if (needed->next != NULL) 2534 initlist_add_neededs(needed->next, list); 2535 2536 /* Process the current needed object. */ 2537 if (needed->obj != NULL) 2538 initlist_add_objects(needed->obj, needed->obj, list); 2539 } 2540 2541 /* 2542 * Scan all of the DAGs rooted in the range of objects from "obj" to 2543 * "tail" and add their init functions to "list". This recurses over 2544 * the DAGs and ensure the proper init ordering such that each object's 2545 * needed libraries are initialized before the object itself. At the 2546 * same time, this function adds the objects to the global finalization 2547 * list "list_fini" in the opposite order. The write lock must be 2548 * held when this function is called. 2549 */ 2550 static void 2551 initlist_add_objects(Obj_Entry *obj, Obj_Entry *tail, Objlist *list) 2552 { 2553 Obj_Entry *nobj; 2554 2555 if (obj->init_scanned || obj->init_done) 2556 return; 2557 obj->init_scanned = true; 2558 2559 /* Recursively process the successor objects. */ 2560 nobj = globallist_next(obj); 2561 if (nobj != NULL && obj != tail) 2562 initlist_add_objects(nobj, tail, list); 2563 2564 /* Recursively process the needed objects. */ 2565 if (obj->needed != NULL) 2566 initlist_add_neededs(obj->needed, list); 2567 if (obj->needed_filtees != NULL) 2568 initlist_add_neededs(obj->needed_filtees, list); 2569 if (obj->needed_aux_filtees != NULL) 2570 initlist_add_neededs(obj->needed_aux_filtees, list); 2571 2572 /* Add the object to the init list. */ 2573 objlist_push_tail(list, obj); 2574 2575 /* Add the object to the global fini list in the reverse order. */ 2576 if ((obj->fini != (Elf_Addr)NULL || obj->fini_array != (Elf_Addr)NULL) 2577 && !obj->on_fini_list) { 2578 objlist_push_head(&list_fini, obj); 2579 obj->on_fini_list = true; 2580 } 2581 } 2582 2583 static void 2584 free_needed_filtees(Needed_Entry *n, RtldLockState *lockstate) 2585 { 2586 Needed_Entry *needed, *needed1; 2587 2588 for (needed = n; needed != NULL; needed = needed->next) { 2589 if (needed->obj != NULL) { 2590 dlclose_locked(needed->obj, lockstate); 2591 needed->obj = NULL; 2592 } 2593 } 2594 for (needed = n; needed != NULL; needed = needed1) { 2595 needed1 = needed->next; 2596 free(needed); 2597 } 2598 } 2599 2600 static void 2601 unload_filtees(Obj_Entry *obj, RtldLockState *lockstate) 2602 { 2603 2604 free_needed_filtees(obj->needed_filtees, lockstate); 2605 obj->needed_filtees = NULL; 2606 free_needed_filtees(obj->needed_aux_filtees, lockstate); 2607 obj->needed_aux_filtees = NULL; 2608 obj->filtees_loaded = false; 2609 } 2610 2611 static void 2612 load_filtee1(Obj_Entry *obj, Needed_Entry *needed, int flags, 2613 RtldLockState *lockstate) 2614 { 2615 2616 for (; needed != NULL; needed = needed->next) { 2617 needed->obj = dlopen_object(obj->strtab + needed->name, -1, obj, 2618 flags, ((ld_loadfltr || obj->z_loadfltr) ? RTLD_NOW : RTLD_LAZY) | 2619 RTLD_LOCAL, lockstate); 2620 } 2621 } 2622 2623 static void 2624 load_filtees(Obj_Entry *obj, int flags, RtldLockState *lockstate) 2625 { 2626 if (obj->filtees_loaded || obj->filtees_loading) 2627 return; 2628 lock_restart_for_upgrade(lockstate); 2629 obj->filtees_loading = true; 2630 load_filtee1(obj, obj->needed_filtees, flags, lockstate); 2631 load_filtee1(obj, obj->needed_aux_filtees, flags, lockstate); 2632 obj->filtees_loaded = true; 2633 obj->filtees_loading = false; 2634 } 2635 2636 static int 2637 process_needed(Obj_Entry *obj, Needed_Entry *needed, int flags) 2638 { 2639 Obj_Entry *obj1; 2640 2641 for (; needed != NULL; needed = needed->next) { 2642 obj1 = needed->obj = load_object(obj->strtab + needed->name, -1, obj, 2643 flags & ~RTLD_LO_NOLOAD); 2644 if (obj1 == NULL && !ld_tracing && (flags & RTLD_LO_FILTEES) == 0) 2645 return (-1); 2646 } 2647 return (0); 2648 } 2649 2650 /* 2651 * Given a shared object, traverse its list of needed objects, and load 2652 * each of them. Returns 0 on success. Generates an error message and 2653 * returns -1 on failure. 2654 */ 2655 static int 2656 load_needed_objects(Obj_Entry *first, int flags) 2657 { 2658 Obj_Entry *obj; 2659 2660 for (obj = first; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 2661 if (obj->marker) 2662 continue; 2663 if (process_needed(obj, obj->needed, flags) == -1) 2664 return (-1); 2665 } 2666 return (0); 2667 } 2668 2669 static int 2670 load_preload_objects(const char *penv, bool isfd) 2671 { 2672 Obj_Entry *obj; 2673 const char *name; 2674 size_t len; 2675 char savech, *p, *psave; 2676 int fd; 2677 static const char delim[] = " \t:;"; 2678 2679 if (penv == NULL) 2680 return (0); 2681 2682 p = psave = xstrdup(penv); 2683 p += strspn(p, delim); 2684 while (*p != '\0') { 2685 len = strcspn(p, delim); 2686 2687 savech = p[len]; 2688 p[len] = '\0'; 2689 if (isfd) { 2690 name = NULL; 2691 fd = parse_integer(p); 2692 if (fd == -1) { 2693 free(psave); 2694 return (-1); 2695 } 2696 } else { 2697 name = p; 2698 fd = -1; 2699 } 2700 2701 obj = load_object(name, fd, NULL, 0); 2702 if (obj == NULL) { 2703 free(psave); 2704 return (-1); /* XXX - cleanup */ 2705 } 2706 obj->z_interpose = true; 2707 p[len] = savech; 2708 p += len; 2709 p += strspn(p, delim); 2710 } 2711 LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL); 2712 2713 free(psave); 2714 return (0); 2715 } 2716 2717 static const char * 2718 printable_path(const char *path) 2719 { 2720 2721 return (path == NULL ? "<unknown>" : path); 2722 } 2723 2724 /* 2725 * Load a shared object into memory, if it is not already loaded. The 2726 * object may be specified by name or by user-supplied file descriptor 2727 * fd_u. In the later case, the fd_u descriptor is not closed, but its 2728 * duplicate is. 2729 * 2730 * Returns a pointer to the Obj_Entry for the object. Returns NULL 2731 * on failure. 2732 */ 2733 static Obj_Entry * 2734 load_object(const char *name, int fd_u, const Obj_Entry *refobj, int flags) 2735 { 2736 Obj_Entry *obj; 2737 int fd; 2738 struct stat sb; 2739 char *path; 2740 2741 fd = -1; 2742 if (name != NULL) { 2743 TAILQ_FOREACH(obj, &obj_list, next) { 2744 if (obj->marker || obj->doomed) 2745 continue; 2746 if (object_match_name(obj, name)) 2747 return (obj); 2748 } 2749 2750 path = find_library(name, refobj, &fd); 2751 if (path == NULL) 2752 return (NULL); 2753 } else 2754 path = NULL; 2755 2756 if (fd >= 0) { 2757 /* 2758 * search_library_pathfds() opens a fresh file descriptor for the 2759 * library, so there is no need to dup(). 2760 */ 2761 } else if (fd_u == -1) { 2762 /* 2763 * If we didn't find a match by pathname, or the name is not 2764 * supplied, open the file and check again by device and inode. 2765 * This avoids false mismatches caused by multiple links or ".." 2766 * in pathnames. 2767 * 2768 * To avoid a race, we open the file and use fstat() rather than 2769 * using stat(). 2770 */ 2771 if ((fd = open(path, O_RDONLY | O_CLOEXEC | O_VERIFY)) == -1) { 2772 _rtld_error("Cannot open \"%s\"", path); 2773 free(path); 2774 return (NULL); 2775 } 2776 } else { 2777 fd = fcntl(fd_u, F_DUPFD_CLOEXEC, 0); 2778 if (fd == -1) { 2779 _rtld_error("Cannot dup fd"); 2780 free(path); 2781 return (NULL); 2782 } 2783 } 2784 if (fstat(fd, &sb) == -1) { 2785 _rtld_error("Cannot fstat \"%s\"", printable_path(path)); 2786 close(fd); 2787 free(path); 2788 return (NULL); 2789 } 2790 TAILQ_FOREACH(obj, &obj_list, next) { 2791 if (obj->marker || obj->doomed) 2792 continue; 2793 if (obj->ino == sb.st_ino && obj->dev == sb.st_dev) 2794 break; 2795 } 2796 if (obj != NULL) { 2797 if (name != NULL) 2798 object_add_name(obj, name); 2799 free(path); 2800 close(fd); 2801 return (obj); 2802 } 2803 if (flags & RTLD_LO_NOLOAD) { 2804 free(path); 2805 close(fd); 2806 return (NULL); 2807 } 2808 2809 /* First use of this object, so we must map it in */ 2810 obj = do_load_object(fd, name, path, &sb, flags); 2811 if (obj == NULL) 2812 free(path); 2813 close(fd); 2814 2815 return (obj); 2816 } 2817 2818 static Obj_Entry * 2819 do_load_object(int fd, const char *name, char *path, struct stat *sbp, 2820 int flags) 2821 { 2822 Obj_Entry *obj; 2823 struct statfs fs; 2824 2825 /* 2826 * First, make sure that environment variables haven't been 2827 * used to circumvent the noexec flag on a filesystem. 2828 * We ignore fstatfs(2) failures, since fd might reference 2829 * not a file, e.g. shmfd. 2830 */ 2831 if (dangerous_ld_env && fstatfs(fd, &fs) == 0 && 2832 (fs.f_flags & MNT_NOEXEC) != 0) { 2833 _rtld_error("Cannot execute objects on %s", fs.f_mntonname); 2834 return (NULL); 2835 } 2836 2837 dbg("loading \"%s\"", printable_path(path)); 2838 obj = map_object(fd, printable_path(path), sbp); 2839 if (obj == NULL) 2840 return (NULL); 2841 2842 /* 2843 * If DT_SONAME is present in the object, digest_dynamic2 already 2844 * added it to the object names. 2845 */ 2846 if (name != NULL) 2847 object_add_name(obj, name); 2848 obj->path = path; 2849 if (!digest_dynamic(obj, 0)) 2850 goto errp; 2851 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", obj->path, 2852 obj->valid_hash_sysv, obj->valid_hash_gnu, obj->dynsymcount); 2853 if (obj->z_pie && (flags & RTLD_LO_TRACE) == 0) { 2854 dbg("refusing to load PIE executable \"%s\"", obj->path); 2855 _rtld_error("Cannot load PIE binary %s as DSO", obj->path); 2856 goto errp; 2857 } 2858 if (obj->z_noopen && (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) == 2859 RTLD_LO_DLOPEN) { 2860 dbg("refusing to load non-loadable \"%s\"", obj->path); 2861 _rtld_error("Cannot dlopen non-loadable %s", obj->path); 2862 goto errp; 2863 } 2864 2865 obj->dlopened = (flags & RTLD_LO_DLOPEN) != 0; 2866 TAILQ_INSERT_TAIL(&obj_list, obj, next); 2867 obj_count++; 2868 obj_loads++; 2869 linkmap_add(obj); /* for GDB & dlinfo() */ 2870 max_stack_flags |= obj->stack_flags; 2871 2872 dbg(" %p .. %p: %s", obj->mapbase, 2873 obj->mapbase + obj->mapsize - 1, obj->path); 2874 if (obj->textrel) 2875 dbg(" WARNING: %s has impure text", obj->path); 2876 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 2877 obj->path); 2878 2879 return (obj); 2880 2881 errp: 2882 munmap(obj->mapbase, obj->mapsize); 2883 obj_free(obj); 2884 return (NULL); 2885 } 2886 2887 static int 2888 load_kpreload(const void *addr) 2889 { 2890 Obj_Entry *obj; 2891 const Elf_Ehdr *ehdr; 2892 const Elf_Phdr *phdr, *phlimit, *phdyn, *seg0, *segn; 2893 static const char kname[] = "[vdso]"; 2894 2895 ehdr = addr; 2896 if (!check_elf_headers(ehdr, "kpreload")) 2897 return (-1); 2898 obj = obj_new(); 2899 phdr = (const Elf_Phdr *)((const char *)addr + ehdr->e_phoff); 2900 obj->phdr = phdr; 2901 obj->phsize = ehdr->e_phnum * sizeof(*phdr); 2902 phlimit = phdr + ehdr->e_phnum; 2903 seg0 = segn = NULL; 2904 2905 for (; phdr < phlimit; phdr++) { 2906 switch (phdr->p_type) { 2907 case PT_DYNAMIC: 2908 phdyn = phdr; 2909 break; 2910 case PT_GNU_STACK: 2911 /* Absense of PT_GNU_STACK implies stack_flags == 0. */ 2912 obj->stack_flags = phdr->p_flags; 2913 break; 2914 case PT_LOAD: 2915 if (seg0 == NULL || seg0->p_vaddr > phdr->p_vaddr) 2916 seg0 = phdr; 2917 if (segn == NULL || segn->p_vaddr + segn->p_memsz < 2918 phdr->p_vaddr + phdr->p_memsz) 2919 segn = phdr; 2920 break; 2921 } 2922 } 2923 2924 obj->mapbase = __DECONST(caddr_t, addr); 2925 obj->mapsize = segn->p_vaddr + segn->p_memsz - (Elf_Addr)addr; 2926 obj->vaddrbase = 0; 2927 obj->relocbase = obj->mapbase; 2928 2929 object_add_name(obj, kname); 2930 obj->path = xstrdup(kname); 2931 obj->dynamic = (const Elf_Dyn *)(obj->relocbase + phdyn->p_vaddr); 2932 2933 if (!digest_dynamic(obj, 0)) { 2934 obj_free(obj); 2935 return (-1); 2936 } 2937 2938 /* 2939 * We assume that kernel-preloaded object does not need 2940 * relocation. It is currently written into read-only page, 2941 * handling relocations would mean we need to allocate at 2942 * least one additional page per AS. 2943 */ 2944 dbg("%s mapbase %p phdrs %p PT_LOAD phdr %p vaddr %p dynamic %p", 2945 obj->path, obj->mapbase, obj->phdr, seg0, 2946 obj->relocbase + seg0->p_vaddr, obj->dynamic); 2947 2948 TAILQ_INSERT_TAIL(&obj_list, obj, next); 2949 obj_count++; 2950 obj_loads++; 2951 linkmap_add(obj); /* for GDB & dlinfo() */ 2952 max_stack_flags |= obj->stack_flags; 2953 2954 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, 0, 0, obj->path); 2955 return (0); 2956 } 2957 2958 Obj_Entry * 2959 obj_from_addr(const void *addr) 2960 { 2961 Obj_Entry *obj; 2962 2963 TAILQ_FOREACH(obj, &obj_list, next) { 2964 if (obj->marker) 2965 continue; 2966 if (addr < (void *) obj->mapbase) 2967 continue; 2968 if (addr < (void *)(obj->mapbase + obj->mapsize)) 2969 return obj; 2970 } 2971 return (NULL); 2972 } 2973 2974 static void 2975 preinit_main(void) 2976 { 2977 Elf_Addr *preinit_addr; 2978 int index; 2979 2980 preinit_addr = (Elf_Addr *)obj_main->preinit_array; 2981 if (preinit_addr == NULL) 2982 return; 2983 2984 for (index = 0; index < obj_main->preinit_array_num; index++) { 2985 if (preinit_addr[index] != 0 && preinit_addr[index] != 1) { 2986 dbg("calling preinit function for %s at %p", obj_main->path, 2987 (void *)preinit_addr[index]); 2988 LD_UTRACE(UTRACE_INIT_CALL, obj_main, (void *)preinit_addr[index], 2989 0, 0, obj_main->path); 2990 call_init_pointer(obj_main, preinit_addr[index]); 2991 } 2992 } 2993 } 2994 2995 /* 2996 * Call the finalization functions for each of the objects in "list" 2997 * belonging to the DAG of "root" and referenced once. If NULL "root" 2998 * is specified, every finalization function will be called regardless 2999 * of the reference count and the list elements won't be freed. All of 3000 * the objects are expected to have non-NULL fini functions. 3001 */ 3002 static void 3003 objlist_call_fini(Objlist *list, Obj_Entry *root, RtldLockState *lockstate) 3004 { 3005 Objlist_Entry *elm; 3006 struct dlerror_save *saved_msg; 3007 Elf_Addr *fini_addr; 3008 int index; 3009 3010 assert(root == NULL || root->refcount == 1); 3011 3012 if (root != NULL) 3013 root->doomed = true; 3014 3015 /* 3016 * Preserve the current error message since a fini function might 3017 * call into the dynamic linker and overwrite it. 3018 */ 3019 saved_msg = errmsg_save(); 3020 do { 3021 STAILQ_FOREACH(elm, list, link) { 3022 if (root != NULL && (elm->obj->refcount != 1 || 3023 objlist_find(&root->dagmembers, elm->obj) == NULL)) 3024 continue; 3025 /* Remove object from fini list to prevent recursive invocation. */ 3026 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 3027 /* Ensure that new references cannot be acquired. */ 3028 elm->obj->doomed = true; 3029 3030 hold_object(elm->obj); 3031 lock_release(rtld_bind_lock, lockstate); 3032 /* 3033 * It is legal to have both DT_FINI and DT_FINI_ARRAY defined. 3034 * When this happens, DT_FINI_ARRAY is processed first. 3035 */ 3036 fini_addr = (Elf_Addr *)elm->obj->fini_array; 3037 if (fini_addr != NULL && elm->obj->fini_array_num > 0) { 3038 for (index = elm->obj->fini_array_num - 1; index >= 0; 3039 index--) { 3040 if (fini_addr[index] != 0 && fini_addr[index] != 1) { 3041 dbg("calling fini function for %s at %p", 3042 elm->obj->path, (void *)fini_addr[index]); 3043 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, 3044 (void *)fini_addr[index], 0, 0, elm->obj->path); 3045 call_initfini_pointer(elm->obj, fini_addr[index]); 3046 } 3047 } 3048 } 3049 if (elm->obj->fini != (Elf_Addr)NULL) { 3050 dbg("calling fini function for %s at %p", elm->obj->path, 3051 (void *)elm->obj->fini); 3052 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, (void *)elm->obj->fini, 3053 0, 0, elm->obj->path); 3054 call_initfini_pointer(elm->obj, elm->obj->fini); 3055 } 3056 wlock_acquire(rtld_bind_lock, lockstate); 3057 unhold_object(elm->obj); 3058 /* No need to free anything if process is going down. */ 3059 if (root != NULL) 3060 free(elm); 3061 /* 3062 * We must restart the list traversal after every fini call 3063 * because a dlclose() call from the fini function or from 3064 * another thread might have modified the reference counts. 3065 */ 3066 break; 3067 } 3068 } while (elm != NULL); 3069 errmsg_restore(saved_msg); 3070 } 3071 3072 /* 3073 * Call the initialization functions for each of the objects in 3074 * "list". All of the objects are expected to have non-NULL init 3075 * functions. 3076 */ 3077 static void 3078 objlist_call_init(Objlist *list, RtldLockState *lockstate) 3079 { 3080 Objlist_Entry *elm; 3081 Obj_Entry *obj; 3082 struct dlerror_save *saved_msg; 3083 Elf_Addr *init_addr; 3084 void (*reg)(void (*)(void)); 3085 int index; 3086 3087 /* 3088 * Clean init_scanned flag so that objects can be rechecked and 3089 * possibly initialized earlier if any of vectors called below 3090 * cause the change by using dlopen. 3091 */ 3092 TAILQ_FOREACH(obj, &obj_list, next) { 3093 if (obj->marker) 3094 continue; 3095 obj->init_scanned = false; 3096 } 3097 3098 /* 3099 * Preserve the current error message since an init function might 3100 * call into the dynamic linker and overwrite it. 3101 */ 3102 saved_msg = errmsg_save(); 3103 STAILQ_FOREACH(elm, list, link) { 3104 if (elm->obj->init_done) /* Initialized early. */ 3105 continue; 3106 /* 3107 * Race: other thread might try to use this object before current 3108 * one completes the initialization. Not much can be done here 3109 * without better locking. 3110 */ 3111 elm->obj->init_done = true; 3112 hold_object(elm->obj); 3113 reg = NULL; 3114 if (elm->obj == obj_main && obj_main->crt_no_init) { 3115 reg = (void (*)(void (*)(void)))get_program_var_addr( 3116 "__libc_atexit", lockstate); 3117 } 3118 lock_release(rtld_bind_lock, lockstate); 3119 if (reg != NULL) { 3120 reg(rtld_exit); 3121 rtld_exit_ptr = rtld_nop_exit; 3122 } 3123 3124 /* 3125 * It is legal to have both DT_INIT and DT_INIT_ARRAY defined. 3126 * When this happens, DT_INIT is processed first. 3127 */ 3128 if (elm->obj->init != (Elf_Addr)NULL) { 3129 dbg("calling init function for %s at %p", elm->obj->path, 3130 (void *)elm->obj->init); 3131 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, (void *)elm->obj->init, 3132 0, 0, elm->obj->path); 3133 call_init_pointer(elm->obj, elm->obj->init); 3134 } 3135 init_addr = (Elf_Addr *)elm->obj->init_array; 3136 if (init_addr != NULL) { 3137 for (index = 0; index < elm->obj->init_array_num; index++) { 3138 if (init_addr[index] != 0 && init_addr[index] != 1) { 3139 dbg("calling init function for %s at %p", elm->obj->path, 3140 (void *)init_addr[index]); 3141 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, 3142 (void *)init_addr[index], 0, 0, elm->obj->path); 3143 call_init_pointer(elm->obj, init_addr[index]); 3144 } 3145 } 3146 } 3147 wlock_acquire(rtld_bind_lock, lockstate); 3148 unhold_object(elm->obj); 3149 } 3150 errmsg_restore(saved_msg); 3151 } 3152 3153 static void 3154 objlist_clear(Objlist *list) 3155 { 3156 Objlist_Entry *elm; 3157 3158 while (!STAILQ_EMPTY(list)) { 3159 elm = STAILQ_FIRST(list); 3160 STAILQ_REMOVE_HEAD(list, link); 3161 free(elm); 3162 } 3163 } 3164 3165 static Objlist_Entry * 3166 objlist_find(Objlist *list, const Obj_Entry *obj) 3167 { 3168 Objlist_Entry *elm; 3169 3170 STAILQ_FOREACH(elm, list, link) 3171 if (elm->obj == obj) 3172 return elm; 3173 return (NULL); 3174 } 3175 3176 static void 3177 objlist_init(Objlist *list) 3178 { 3179 STAILQ_INIT(list); 3180 } 3181 3182 static void 3183 objlist_push_head(Objlist *list, Obj_Entry *obj) 3184 { 3185 Objlist_Entry *elm; 3186 3187 elm = NEW(Objlist_Entry); 3188 elm->obj = obj; 3189 STAILQ_INSERT_HEAD(list, elm, link); 3190 } 3191 3192 static void 3193 objlist_push_tail(Objlist *list, Obj_Entry *obj) 3194 { 3195 Objlist_Entry *elm; 3196 3197 elm = NEW(Objlist_Entry); 3198 elm->obj = obj; 3199 STAILQ_INSERT_TAIL(list, elm, link); 3200 } 3201 3202 static void 3203 objlist_put_after(Objlist *list, Obj_Entry *listobj, Obj_Entry *obj) 3204 { 3205 Objlist_Entry *elm, *listelm; 3206 3207 STAILQ_FOREACH(listelm, list, link) { 3208 if (listelm->obj == listobj) 3209 break; 3210 } 3211 elm = NEW(Objlist_Entry); 3212 elm->obj = obj; 3213 if (listelm != NULL) 3214 STAILQ_INSERT_AFTER(list, listelm, elm, link); 3215 else 3216 STAILQ_INSERT_TAIL(list, elm, link); 3217 } 3218 3219 static void 3220 objlist_remove(Objlist *list, Obj_Entry *obj) 3221 { 3222 Objlist_Entry *elm; 3223 3224 if ((elm = objlist_find(list, obj)) != NULL) { 3225 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 3226 free(elm); 3227 } 3228 } 3229 3230 /* 3231 * Relocate dag rooted in the specified object. 3232 * Returns 0 on success, or -1 on failure. 3233 */ 3234 3235 static int 3236 relocate_object_dag(Obj_Entry *root, bool bind_now, Obj_Entry *rtldobj, 3237 int flags, RtldLockState *lockstate) 3238 { 3239 Objlist_Entry *elm; 3240 int error; 3241 3242 error = 0; 3243 STAILQ_FOREACH(elm, &root->dagmembers, link) { 3244 error = relocate_object(elm->obj, bind_now, rtldobj, flags, 3245 lockstate); 3246 if (error == -1) 3247 break; 3248 } 3249 return (error); 3250 } 3251 3252 /* 3253 * Prepare for, or clean after, relocating an object marked with 3254 * DT_TEXTREL or DF_TEXTREL. Before relocating, all read-only 3255 * segments are remapped read-write. After relocations are done, the 3256 * segment's permissions are returned back to the modes specified in 3257 * the phdrs. If any relocation happened, or always for wired 3258 * program, COW is triggered. 3259 */ 3260 static int 3261 reloc_textrel_prot(Obj_Entry *obj, bool before) 3262 { 3263 const Elf_Phdr *ph; 3264 void *base; 3265 size_t l, sz; 3266 int prot; 3267 3268 for (l = obj->phsize / sizeof(*ph), ph = obj->phdr; l > 0; 3269 l--, ph++) { 3270 if (ph->p_type != PT_LOAD || (ph->p_flags & PF_W) != 0) 3271 continue; 3272 base = obj->relocbase + rtld_trunc_page(ph->p_vaddr); 3273 sz = rtld_round_page(ph->p_vaddr + ph->p_filesz) - 3274 rtld_trunc_page(ph->p_vaddr); 3275 prot = before ? (PROT_READ | PROT_WRITE) : 3276 convert_prot(ph->p_flags); 3277 if (mprotect(base, sz, prot) == -1) { 3278 _rtld_error("%s: Cannot write-%sable text segment: %s", 3279 obj->path, before ? "en" : "dis", 3280 rtld_strerror(errno)); 3281 return (-1); 3282 } 3283 } 3284 return (0); 3285 } 3286 3287 /* Process RELR relative relocations. */ 3288 static void 3289 reloc_relr(Obj_Entry *obj) 3290 { 3291 const Elf_Relr *relr, *relrlim; 3292 Elf_Addr *where; 3293 3294 relrlim = (const Elf_Relr *)((const char *)obj->relr + obj->relrsize); 3295 for (relr = obj->relr; relr < relrlim; relr++) { 3296 Elf_Relr entry = *relr; 3297 3298 if ((entry & 1) == 0) { 3299 where = (Elf_Addr *)(obj->relocbase + entry); 3300 *where++ += (Elf_Addr)obj->relocbase; 3301 } else { 3302 for (long i = 0; (entry >>= 1) != 0; i++) 3303 if ((entry & 1) != 0) 3304 where[i] += (Elf_Addr)obj->relocbase; 3305 where += CHAR_BIT * sizeof(Elf_Relr) - 1; 3306 } 3307 } 3308 } 3309 3310 /* 3311 * Relocate single object. 3312 * Returns 0 on success, or -1 on failure. 3313 */ 3314 static int 3315 relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, 3316 int flags, RtldLockState *lockstate) 3317 { 3318 3319 if (obj->relocated) 3320 return (0); 3321 obj->relocated = true; 3322 if (obj != rtldobj) 3323 dbg("relocating \"%s\"", obj->path); 3324 3325 if (obj->symtab == NULL || obj->strtab == NULL || 3326 !(obj->valid_hash_sysv || obj->valid_hash_gnu)) 3327 dbg("object %s has no run-time symbol table", obj->path); 3328 3329 /* There are relocations to the write-protected text segment. */ 3330 if (obj->textrel && reloc_textrel_prot(obj, true) != 0) 3331 return (-1); 3332 3333 /* Process the non-PLT non-IFUNC relocations. */ 3334 if (reloc_non_plt(obj, rtldobj, flags, lockstate)) 3335 return (-1); 3336 reloc_relr(obj); 3337 3338 /* Re-protected the text segment. */ 3339 if (obj->textrel && reloc_textrel_prot(obj, false) != 0) 3340 return (-1); 3341 3342 /* Set the special PLT or GOT entries. */ 3343 init_pltgot(obj); 3344 3345 /* Process the PLT relocations. */ 3346 if (reloc_plt(obj, flags, lockstate) == -1) 3347 return (-1); 3348 /* Relocate the jump slots if we are doing immediate binding. */ 3349 if ((obj->bind_now || bind_now) && reloc_jmpslots(obj, flags, 3350 lockstate) == -1) 3351 return (-1); 3352 3353 if (!obj->mainprog && obj_enforce_relro(obj) == -1) 3354 return (-1); 3355 3356 /* 3357 * Set up the magic number and version in the Obj_Entry. These 3358 * were checked in the crt1.o from the original ElfKit, so we 3359 * set them for backward compatibility. 3360 */ 3361 obj->magic = RTLD_MAGIC; 3362 obj->version = RTLD_VERSION; 3363 3364 return (0); 3365 } 3366 3367 /* 3368 * Relocate newly-loaded shared objects. The argument is a pointer to 3369 * the Obj_Entry for the first such object. All objects from the first 3370 * to the end of the list of objects are relocated. Returns 0 on success, 3371 * or -1 on failure. 3372 */ 3373 static int 3374 relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj, 3375 int flags, RtldLockState *lockstate) 3376 { 3377 Obj_Entry *obj; 3378 int error; 3379 3380 for (error = 0, obj = first; obj != NULL; 3381 obj = TAILQ_NEXT(obj, next)) { 3382 if (obj->marker) 3383 continue; 3384 error = relocate_object(obj, bind_now, rtldobj, flags, 3385 lockstate); 3386 if (error == -1) 3387 break; 3388 } 3389 return (error); 3390 } 3391 3392 /* 3393 * The handling of R_MACHINE_IRELATIVE relocations and jumpslots 3394 * referencing STT_GNU_IFUNC symbols is postponed till the other 3395 * relocations are done. The indirect functions specified as 3396 * ifunc are allowed to call other symbols, so we need to have 3397 * objects relocated before asking for resolution from indirects. 3398 * 3399 * The R_MACHINE_IRELATIVE slots are resolved in greedy fashion, 3400 * instead of the usual lazy handling of PLT slots. It is 3401 * consistent with how GNU does it. 3402 */ 3403 static int 3404 resolve_object_ifunc(Obj_Entry *obj, bool bind_now, int flags, 3405 RtldLockState *lockstate) 3406 { 3407 3408 if (obj->ifuncs_resolved) 3409 return (0); 3410 obj->ifuncs_resolved = true; 3411 if (!obj->irelative && !obj->irelative_nonplt && 3412 !((obj->bind_now || bind_now) && obj->gnu_ifunc) && 3413 !obj->non_plt_gnu_ifunc) 3414 return (0); 3415 if (obj_disable_relro(obj) == -1 || 3416 (obj->irelative && reloc_iresolve(obj, lockstate) == -1) || 3417 (obj->irelative_nonplt && reloc_iresolve_nonplt(obj, 3418 lockstate) == -1) || 3419 ((obj->bind_now || bind_now) && obj->gnu_ifunc && 3420 reloc_gnu_ifunc(obj, flags, lockstate) == -1) || 3421 (obj->non_plt_gnu_ifunc && reloc_non_plt(obj, &obj_rtld, 3422 flags | SYMLOOK_IFUNC, lockstate) == -1) || 3423 obj_enforce_relro(obj) == -1) 3424 return (-1); 3425 return (0); 3426 } 3427 3428 static int 3429 initlist_objects_ifunc(Objlist *list, bool bind_now, int flags, 3430 RtldLockState *lockstate) 3431 { 3432 Objlist_Entry *elm; 3433 Obj_Entry *obj; 3434 3435 STAILQ_FOREACH(elm, list, link) { 3436 obj = elm->obj; 3437 if (obj->marker) 3438 continue; 3439 if (resolve_object_ifunc(obj, bind_now, flags, 3440 lockstate) == -1) 3441 return (-1); 3442 } 3443 return (0); 3444 } 3445 3446 /* 3447 * Cleanup procedure. It will be called (by the atexit mechanism) just 3448 * before the process exits. 3449 */ 3450 static void 3451 rtld_exit(void) 3452 { 3453 RtldLockState lockstate; 3454 3455 wlock_acquire(rtld_bind_lock, &lockstate); 3456 dbg("rtld_exit()"); 3457 objlist_call_fini(&list_fini, NULL, &lockstate); 3458 /* No need to remove the items from the list, since we are exiting. */ 3459 if (!libmap_disable) 3460 lm_fini(); 3461 lock_release(rtld_bind_lock, &lockstate); 3462 } 3463 3464 static void 3465 rtld_nop_exit(void) 3466 { 3467 } 3468 3469 /* 3470 * Iterate over a search path, translate each element, and invoke the 3471 * callback on the result. 3472 */ 3473 static void * 3474 path_enumerate(const char *path, path_enum_proc callback, 3475 const char *refobj_path, void *arg) 3476 { 3477 const char *trans; 3478 if (path == NULL) 3479 return (NULL); 3480 3481 path += strspn(path, ":;"); 3482 while (*path != '\0') { 3483 size_t len; 3484 char *res; 3485 3486 len = strcspn(path, ":;"); 3487 trans = lm_findn(refobj_path, path, len); 3488 if (trans) 3489 res = callback(trans, strlen(trans), arg); 3490 else 3491 res = callback(path, len, arg); 3492 3493 if (res != NULL) 3494 return (res); 3495 3496 path += len; 3497 path += strspn(path, ":;"); 3498 } 3499 3500 return (NULL); 3501 } 3502 3503 struct try_library_args { 3504 const char *name; 3505 size_t namelen; 3506 char *buffer; 3507 size_t buflen; 3508 int fd; 3509 }; 3510 3511 static void * 3512 try_library_path(const char *dir, size_t dirlen, void *param) 3513 { 3514 struct try_library_args *arg; 3515 int fd; 3516 3517 arg = param; 3518 if (*dir == '/' || trust) { 3519 char *pathname; 3520 3521 if (dirlen + 1 + arg->namelen + 1 > arg->buflen) 3522 return (NULL); 3523 3524 pathname = arg->buffer; 3525 strncpy(pathname, dir, dirlen); 3526 pathname[dirlen] = '/'; 3527 strcpy(pathname + dirlen + 1, arg->name); 3528 3529 dbg(" Trying \"%s\"", pathname); 3530 fd = open(pathname, O_RDONLY | O_CLOEXEC | O_VERIFY); 3531 if (fd >= 0) { 3532 dbg(" Opened \"%s\", fd %d", pathname, fd); 3533 pathname = xmalloc(dirlen + 1 + arg->namelen + 1); 3534 strcpy(pathname, arg->buffer); 3535 arg->fd = fd; 3536 return (pathname); 3537 } else { 3538 dbg(" Failed to open \"%s\": %s", 3539 pathname, rtld_strerror(errno)); 3540 } 3541 } 3542 return (NULL); 3543 } 3544 3545 static char * 3546 search_library_path(const char *name, const char *path, 3547 const char *refobj_path, int *fdp) 3548 { 3549 char *p; 3550 struct try_library_args arg; 3551 3552 if (path == NULL) 3553 return (NULL); 3554 3555 arg.name = name; 3556 arg.namelen = strlen(name); 3557 arg.buffer = xmalloc(PATH_MAX); 3558 arg.buflen = PATH_MAX; 3559 arg.fd = -1; 3560 3561 p = path_enumerate(path, try_library_path, refobj_path, &arg); 3562 *fdp = arg.fd; 3563 3564 free(arg.buffer); 3565 3566 return (p); 3567 } 3568 3569 3570 /* 3571 * Finds the library with the given name using the directory descriptors 3572 * listed in the LD_LIBRARY_PATH_FDS environment variable. 3573 * 3574 * Returns a freshly-opened close-on-exec file descriptor for the library, 3575 * or -1 if the library cannot be found. 3576 */ 3577 static char * 3578 search_library_pathfds(const char *name, const char *path, int *fdp) 3579 { 3580 char *envcopy, *fdstr, *found, *last_token; 3581 size_t len; 3582 int dirfd, fd; 3583 3584 dbg("%s('%s', '%s', fdp)", __func__, name, path); 3585 3586 /* Don't load from user-specified libdirs into setuid binaries. */ 3587 if (!trust) 3588 return (NULL); 3589 3590 /* We can't do anything if LD_LIBRARY_PATH_FDS isn't set. */ 3591 if (path == NULL) 3592 return (NULL); 3593 3594 /* LD_LIBRARY_PATH_FDS only works with relative paths. */ 3595 if (name[0] == '/') { 3596 dbg("Absolute path (%s) passed to %s", name, __func__); 3597 return (NULL); 3598 } 3599 3600 /* 3601 * Use strtok_r() to walk the FD:FD:FD list. This requires a local 3602 * copy of the path, as strtok_r rewrites separator tokens 3603 * with '\0'. 3604 */ 3605 found = NULL; 3606 envcopy = xstrdup(path); 3607 for (fdstr = strtok_r(envcopy, ":", &last_token); fdstr != NULL; 3608 fdstr = strtok_r(NULL, ":", &last_token)) { 3609 dirfd = parse_integer(fdstr); 3610 if (dirfd < 0) { 3611 _rtld_error("failed to parse directory FD: '%s'", 3612 fdstr); 3613 break; 3614 } 3615 fd = __sys_openat(dirfd, name, O_RDONLY | O_CLOEXEC | O_VERIFY); 3616 if (fd >= 0) { 3617 *fdp = fd; 3618 len = strlen(fdstr) + strlen(name) + 3; 3619 found = xmalloc(len); 3620 if (rtld_snprintf(found, len, "#%d/%s", dirfd, name) < 0) { 3621 _rtld_error("error generating '%d/%s'", 3622 dirfd, name); 3623 rtld_die(); 3624 } 3625 dbg("open('%s') => %d", found, fd); 3626 break; 3627 } 3628 } 3629 free(envcopy); 3630 3631 return (found); 3632 } 3633 3634 3635 int 3636 dlclose(void *handle) 3637 { 3638 RtldLockState lockstate; 3639 int error; 3640 3641 wlock_acquire(rtld_bind_lock, &lockstate); 3642 error = dlclose_locked(handle, &lockstate); 3643 lock_release(rtld_bind_lock, &lockstate); 3644 return (error); 3645 } 3646 3647 static int 3648 dlclose_locked(void *handle, RtldLockState *lockstate) 3649 { 3650 Obj_Entry *root; 3651 3652 root = dlcheck(handle); 3653 if (root == NULL) 3654 return (-1); 3655 LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount, 3656 root->path); 3657 3658 /* Unreference the object and its dependencies. */ 3659 root->dl_refcount--; 3660 3661 if (root->refcount == 1) { 3662 /* 3663 * The object will be no longer referenced, so we must unload it. 3664 * First, call the fini functions. 3665 */ 3666 objlist_call_fini(&list_fini, root, lockstate); 3667 3668 unref_dag(root); 3669 3670 /* Finish cleaning up the newly-unreferenced objects. */ 3671 GDB_STATE(RT_DELETE,&root->linkmap); 3672 unload_object(root, lockstate); 3673 GDB_STATE(RT_CONSISTENT,NULL); 3674 } else 3675 unref_dag(root); 3676 3677 LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL); 3678 return (0); 3679 } 3680 3681 char * 3682 dlerror(void) 3683 { 3684 if (*(lockinfo.dlerror_seen()) != 0) 3685 return (NULL); 3686 *lockinfo.dlerror_seen() = 1; 3687 return (lockinfo.dlerror_loc()); 3688 } 3689 3690 /* 3691 * This function is deprecated and has no effect. 3692 */ 3693 void 3694 dllockinit(void *context, 3695 void *(*_lock_create)(void *context) __unused, 3696 void (*_rlock_acquire)(void *lock) __unused, 3697 void (*_wlock_acquire)(void *lock) __unused, 3698 void (*_lock_release)(void *lock) __unused, 3699 void (*_lock_destroy)(void *lock) __unused, 3700 void (*context_destroy)(void *context)) 3701 { 3702 static void *cur_context; 3703 static void (*cur_context_destroy)(void *); 3704 3705 /* Just destroy the context from the previous call, if necessary. */ 3706 if (cur_context_destroy != NULL) 3707 cur_context_destroy(cur_context); 3708 cur_context = context; 3709 cur_context_destroy = context_destroy; 3710 } 3711 3712 void * 3713 dlopen(const char *name, int mode) 3714 { 3715 3716 return (rtld_dlopen(name, -1, mode)); 3717 } 3718 3719 void * 3720 fdlopen(int fd, int mode) 3721 { 3722 3723 return (rtld_dlopen(NULL, fd, mode)); 3724 } 3725 3726 static void * 3727 rtld_dlopen(const char *name, int fd, int mode) 3728 { 3729 RtldLockState lockstate; 3730 int lo_flags; 3731 3732 LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name); 3733 ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1"; 3734 if (ld_tracing != NULL) { 3735 rlock_acquire(rtld_bind_lock, &lockstate); 3736 if (sigsetjmp(lockstate.env, 0) != 0) 3737 lock_upgrade(rtld_bind_lock, &lockstate); 3738 environ = __DECONST(char **, *get_program_var_addr("environ", &lockstate)); 3739 lock_release(rtld_bind_lock, &lockstate); 3740 } 3741 lo_flags = RTLD_LO_DLOPEN; 3742 if (mode & RTLD_NODELETE) 3743 lo_flags |= RTLD_LO_NODELETE; 3744 if (mode & RTLD_NOLOAD) 3745 lo_flags |= RTLD_LO_NOLOAD; 3746 if (mode & RTLD_DEEPBIND) 3747 lo_flags |= RTLD_LO_DEEPBIND; 3748 if (ld_tracing != NULL) 3749 lo_flags |= RTLD_LO_TRACE | RTLD_LO_IGNSTLS; 3750 3751 return (dlopen_object(name, fd, obj_main, lo_flags, 3752 mode & (RTLD_MODEMASK | RTLD_GLOBAL), NULL)); 3753 } 3754 3755 static void 3756 dlopen_cleanup(Obj_Entry *obj, RtldLockState *lockstate) 3757 { 3758 3759 obj->dl_refcount--; 3760 unref_dag(obj); 3761 if (obj->refcount == 0) 3762 unload_object(obj, lockstate); 3763 } 3764 3765 static Obj_Entry * 3766 dlopen_object(const char *name, int fd, Obj_Entry *refobj, int lo_flags, 3767 int mode, RtldLockState *lockstate) 3768 { 3769 Obj_Entry *obj; 3770 Objlist initlist; 3771 RtldLockState mlockstate; 3772 int result; 3773 3774 dbg("dlopen_object name \"%s\" fd %d refobj \"%s\" lo_flags %#x mode %#x", 3775 name != NULL ? name : "<null>", fd, refobj == NULL ? "<null>" : 3776 refobj->path, lo_flags, mode); 3777 objlist_init(&initlist); 3778 3779 if (lockstate == NULL && !(lo_flags & RTLD_LO_EARLY)) { 3780 wlock_acquire(rtld_bind_lock, &mlockstate); 3781 lockstate = &mlockstate; 3782 } 3783 GDB_STATE(RT_ADD,NULL); 3784 3785 obj = NULL; 3786 if (name == NULL && fd == -1) { 3787 obj = obj_main; 3788 obj->refcount++; 3789 } else { 3790 obj = load_object(name, fd, refobj, lo_flags); 3791 } 3792 3793 if (obj) { 3794 obj->dl_refcount++; 3795 if (mode & RTLD_GLOBAL && objlist_find(&list_global, obj) == NULL) 3796 objlist_push_tail(&list_global, obj); 3797 3798 if (!obj->init_done) { 3799 /* We loaded something new and have to init something. */ 3800 if ((lo_flags & RTLD_LO_DEEPBIND) != 0) 3801 obj->deepbind = true; 3802 result = 0; 3803 if ((lo_flags & (RTLD_LO_EARLY | RTLD_LO_IGNSTLS)) == 0 && 3804 obj->static_tls && !allocate_tls_offset(obj)) { 3805 _rtld_error("%s: No space available " 3806 "for static Thread Local Storage", obj->path); 3807 result = -1; 3808 } 3809 if (result != -1) 3810 result = load_needed_objects(obj, lo_flags & (RTLD_LO_DLOPEN | 3811 RTLD_LO_EARLY | RTLD_LO_IGNSTLS | RTLD_LO_TRACE)); 3812 init_dag(obj); 3813 ref_dag(obj); 3814 if (result != -1) 3815 result = rtld_verify_versions(&obj->dagmembers); 3816 if (result != -1 && ld_tracing) 3817 goto trace; 3818 if (result == -1 || relocate_object_dag(obj, 3819 (mode & RTLD_MODEMASK) == RTLD_NOW, &obj_rtld, 3820 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 3821 lockstate) == -1) { 3822 dlopen_cleanup(obj, lockstate); 3823 obj = NULL; 3824 } else if (lo_flags & RTLD_LO_EARLY) { 3825 /* 3826 * Do not call the init functions for early loaded 3827 * filtees. The image is still not initialized enough 3828 * for them to work. 3829 * 3830 * Our object is found by the global object list and 3831 * will be ordered among all init calls done right 3832 * before transferring control to main. 3833 */ 3834 } else { 3835 /* Make list of init functions to call. */ 3836 initlist_add_objects(obj, obj, &initlist); 3837 } 3838 /* 3839 * Process all no_delete or global objects here, given 3840 * them own DAGs to prevent their dependencies from being 3841 * unloaded. This has to be done after we have loaded all 3842 * of the dependencies, so that we do not miss any. 3843 */ 3844 if (obj != NULL) 3845 process_z(obj); 3846 } else { 3847 /* 3848 * Bump the reference counts for objects on this DAG. If 3849 * this is the first dlopen() call for the object that was 3850 * already loaded as a dependency, initialize the dag 3851 * starting at it. 3852 */ 3853 init_dag(obj); 3854 ref_dag(obj); 3855 3856 if ((lo_flags & RTLD_LO_TRACE) != 0) 3857 goto trace; 3858 } 3859 if (obj != NULL && ((lo_flags & RTLD_LO_NODELETE) != 0 || 3860 obj->z_nodelete) && !obj->ref_nodel) { 3861 dbg("obj %s nodelete", obj->path); 3862 ref_dag(obj); 3863 obj->z_nodelete = obj->ref_nodel = true; 3864 } 3865 } 3866 3867 LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0, 3868 name); 3869 GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL); 3870 3871 if ((lo_flags & RTLD_LO_EARLY) == 0) { 3872 map_stacks_exec(lockstate); 3873 if (obj != NULL) 3874 distribute_static_tls(&initlist, lockstate); 3875 } 3876 3877 if (initlist_objects_ifunc(&initlist, (mode & RTLD_MODEMASK) == RTLD_NOW, 3878 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 3879 lockstate) == -1) { 3880 objlist_clear(&initlist); 3881 dlopen_cleanup(obj, lockstate); 3882 if (lockstate == &mlockstate) 3883 lock_release(rtld_bind_lock, lockstate); 3884 return (NULL); 3885 } 3886 3887 if (!(lo_flags & RTLD_LO_EARLY)) { 3888 /* Call the init functions. */ 3889 objlist_call_init(&initlist, lockstate); 3890 } 3891 objlist_clear(&initlist); 3892 if (lockstate == &mlockstate) 3893 lock_release(rtld_bind_lock, lockstate); 3894 return (obj); 3895 trace: 3896 trace_loaded_objects(obj, false); 3897 if (lockstate == &mlockstate) 3898 lock_release(rtld_bind_lock, lockstate); 3899 exit(0); 3900 } 3901 3902 static void * 3903 do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve, 3904 int flags) 3905 { 3906 DoneList donelist; 3907 const Obj_Entry *obj, *defobj; 3908 const Elf_Sym *def; 3909 SymLook req; 3910 RtldLockState lockstate; 3911 tls_index ti; 3912 void *sym; 3913 int res; 3914 3915 def = NULL; 3916 defobj = NULL; 3917 symlook_init(&req, name); 3918 req.ventry = ve; 3919 req.flags = flags | SYMLOOK_IN_PLT; 3920 req.lockstate = &lockstate; 3921 3922 LD_UTRACE(UTRACE_DLSYM_START, handle, NULL, 0, 0, name); 3923 rlock_acquire(rtld_bind_lock, &lockstate); 3924 if (sigsetjmp(lockstate.env, 0) != 0) 3925 lock_upgrade(rtld_bind_lock, &lockstate); 3926 if (handle == NULL || handle == RTLD_NEXT || 3927 handle == RTLD_DEFAULT || handle == RTLD_SELF) { 3928 3929 if ((obj = obj_from_addr(retaddr)) == NULL) { 3930 _rtld_error("Cannot determine caller's shared object"); 3931 lock_release(rtld_bind_lock, &lockstate); 3932 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 3933 return (NULL); 3934 } 3935 if (handle == NULL) { /* Just the caller's shared object. */ 3936 res = symlook_obj(&req, obj); 3937 if (res == 0) { 3938 def = req.sym_out; 3939 defobj = req.defobj_out; 3940 } 3941 } else if (handle == RTLD_NEXT || /* Objects after caller's */ 3942 handle == RTLD_SELF) { /* ... caller included */ 3943 if (handle == RTLD_NEXT) 3944 obj = globallist_next(obj); 3945 for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 3946 if (obj->marker) 3947 continue; 3948 res = symlook_obj(&req, obj); 3949 if (res == 0) { 3950 if (def == NULL || (ld_dynamic_weak && 3951 ELF_ST_BIND(req.sym_out->st_info) != STB_WEAK)) { 3952 def = req.sym_out; 3953 defobj = req.defobj_out; 3954 if (!ld_dynamic_weak || 3955 ELF_ST_BIND(def->st_info) != STB_WEAK) 3956 break; 3957 } 3958 } 3959 } 3960 /* 3961 * Search the dynamic linker itself, and possibly resolve the 3962 * symbol from there. This is how the application links to 3963 * dynamic linker services such as dlopen. 3964 * Note that we ignore ld_dynamic_weak == false case, 3965 * always overriding weak symbols by rtld definitions. 3966 */ 3967 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 3968 res = symlook_obj(&req, &obj_rtld); 3969 if (res == 0) { 3970 def = req.sym_out; 3971 defobj = req.defobj_out; 3972 } 3973 } 3974 } else { 3975 assert(handle == RTLD_DEFAULT); 3976 res = symlook_default(&req, obj); 3977 if (res == 0) { 3978 defobj = req.defobj_out; 3979 def = req.sym_out; 3980 } 3981 } 3982 } else { 3983 if ((obj = dlcheck(handle)) == NULL) { 3984 lock_release(rtld_bind_lock, &lockstate); 3985 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 3986 return (NULL); 3987 } 3988 3989 donelist_init(&donelist); 3990 if (obj->mainprog) { 3991 /* Handle obtained by dlopen(NULL, ...) implies global scope. */ 3992 res = symlook_global(&req, &donelist); 3993 if (res == 0) { 3994 def = req.sym_out; 3995 defobj = req.defobj_out; 3996 } 3997 /* 3998 * Search the dynamic linker itself, and possibly resolve the 3999 * symbol from there. This is how the application links to 4000 * dynamic linker services such as dlopen. 4001 */ 4002 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 4003 res = symlook_obj(&req, &obj_rtld); 4004 if (res == 0) { 4005 def = req.sym_out; 4006 defobj = req.defobj_out; 4007 } 4008 } 4009 } 4010 else { 4011 /* Search the whole DAG rooted at the given object. */ 4012 res = symlook_list(&req, &obj->dagmembers, &donelist); 4013 if (res == 0) { 4014 def = req.sym_out; 4015 defobj = req.defobj_out; 4016 } 4017 } 4018 } 4019 4020 if (def != NULL) { 4021 lock_release(rtld_bind_lock, &lockstate); 4022 4023 /* 4024 * The value required by the caller is derived from the value 4025 * of the symbol. this is simply the relocated value of the 4026 * symbol. 4027 */ 4028 if (ELF_ST_TYPE(def->st_info) == STT_FUNC) 4029 sym = make_function_pointer(def, defobj); 4030 else if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 4031 sym = rtld_resolve_ifunc(defobj, def); 4032 else if (ELF_ST_TYPE(def->st_info) == STT_TLS) { 4033 ti.ti_module = defobj->tlsindex; 4034 ti.ti_offset = def->st_value; 4035 sym = __tls_get_addr(&ti); 4036 } else 4037 sym = defobj->relocbase + def->st_value; 4038 LD_UTRACE(UTRACE_DLSYM_STOP, handle, sym, 0, 0, name); 4039 return (sym); 4040 } 4041 4042 _rtld_error("Undefined symbol \"%s%s%s\"", name, ve != NULL ? "@" : "", 4043 ve != NULL ? ve->name : ""); 4044 lock_release(rtld_bind_lock, &lockstate); 4045 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 4046 return (NULL); 4047 } 4048 4049 void * 4050 dlsym(void *handle, const char *name) 4051 { 4052 return (do_dlsym(handle, name, __builtin_return_address(0), NULL, 4053 SYMLOOK_DLSYM)); 4054 } 4055 4056 dlfunc_t 4057 dlfunc(void *handle, const char *name) 4058 { 4059 union { 4060 void *d; 4061 dlfunc_t f; 4062 } rv; 4063 4064 rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL, 4065 SYMLOOK_DLSYM); 4066 return (rv.f); 4067 } 4068 4069 void * 4070 dlvsym(void *handle, const char *name, const char *version) 4071 { 4072 Ver_Entry ventry; 4073 4074 ventry.name = version; 4075 ventry.file = NULL; 4076 ventry.hash = elf_hash(version); 4077 ventry.flags= 0; 4078 return (do_dlsym(handle, name, __builtin_return_address(0), &ventry, 4079 SYMLOOK_DLSYM)); 4080 } 4081 4082 int 4083 _rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info) 4084 { 4085 const Obj_Entry *obj; 4086 RtldLockState lockstate; 4087 4088 rlock_acquire(rtld_bind_lock, &lockstate); 4089 obj = obj_from_addr(addr); 4090 if (obj == NULL) { 4091 _rtld_error("No shared object contains address"); 4092 lock_release(rtld_bind_lock, &lockstate); 4093 return (0); 4094 } 4095 rtld_fill_dl_phdr_info(obj, phdr_info); 4096 lock_release(rtld_bind_lock, &lockstate); 4097 return (1); 4098 } 4099 4100 int 4101 dladdr(const void *addr, Dl_info *info) 4102 { 4103 const Obj_Entry *obj; 4104 const Elf_Sym *def; 4105 void *symbol_addr; 4106 unsigned long symoffset; 4107 RtldLockState lockstate; 4108 4109 rlock_acquire(rtld_bind_lock, &lockstate); 4110 obj = obj_from_addr(addr); 4111 if (obj == NULL) { 4112 _rtld_error("No shared object contains address"); 4113 lock_release(rtld_bind_lock, &lockstate); 4114 return (0); 4115 } 4116 info->dli_fname = obj->path; 4117 info->dli_fbase = obj->mapbase; 4118 info->dli_saddr = (void *)0; 4119 info->dli_sname = NULL; 4120 4121 /* 4122 * Walk the symbol list looking for the symbol whose address is 4123 * closest to the address sent in. 4124 */ 4125 for (symoffset = 0; symoffset < obj->dynsymcount; symoffset++) { 4126 def = obj->symtab + symoffset; 4127 4128 /* 4129 * For skip the symbol if st_shndx is either SHN_UNDEF or 4130 * SHN_COMMON. 4131 */ 4132 if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON) 4133 continue; 4134 4135 /* 4136 * If the symbol is greater than the specified address, or if it 4137 * is further away from addr than the current nearest symbol, 4138 * then reject it. 4139 */ 4140 symbol_addr = obj->relocbase + def->st_value; 4141 if (symbol_addr > addr || symbol_addr < info->dli_saddr) 4142 continue; 4143 4144 /* Update our idea of the nearest symbol. */ 4145 info->dli_sname = obj->strtab + def->st_name; 4146 info->dli_saddr = symbol_addr; 4147 4148 /* Exact match? */ 4149 if (info->dli_saddr == addr) 4150 break; 4151 } 4152 lock_release(rtld_bind_lock, &lockstate); 4153 return (1); 4154 } 4155 4156 int 4157 dlinfo(void *handle, int request, void *p) 4158 { 4159 const Obj_Entry *obj; 4160 RtldLockState lockstate; 4161 int error; 4162 4163 rlock_acquire(rtld_bind_lock, &lockstate); 4164 4165 if (handle == NULL || handle == RTLD_SELF) { 4166 void *retaddr; 4167 4168 retaddr = __builtin_return_address(0); /* __GNUC__ only */ 4169 if ((obj = obj_from_addr(retaddr)) == NULL) 4170 _rtld_error("Cannot determine caller's shared object"); 4171 } else 4172 obj = dlcheck(handle); 4173 4174 if (obj == NULL) { 4175 lock_release(rtld_bind_lock, &lockstate); 4176 return (-1); 4177 } 4178 4179 error = 0; 4180 switch (request) { 4181 case RTLD_DI_LINKMAP: 4182 *((struct link_map const **)p) = &obj->linkmap; 4183 break; 4184 case RTLD_DI_ORIGIN: 4185 error = rtld_dirname(obj->path, p); 4186 break; 4187 4188 case RTLD_DI_SERINFOSIZE: 4189 case RTLD_DI_SERINFO: 4190 error = do_search_info(obj, request, (struct dl_serinfo *)p); 4191 break; 4192 4193 default: 4194 _rtld_error("Invalid request %d passed to dlinfo()", request); 4195 error = -1; 4196 } 4197 4198 lock_release(rtld_bind_lock, &lockstate); 4199 4200 return (error); 4201 } 4202 4203 static void 4204 rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info) 4205 { 4206 uintptr_t **dtvp; 4207 4208 phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase; 4209 phdr_info->dlpi_name = obj->path; 4210 phdr_info->dlpi_phdr = obj->phdr; 4211 phdr_info->dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]); 4212 phdr_info->dlpi_tls_modid = obj->tlsindex; 4213 dtvp = &_tcb_get()->tcb_dtv; 4214 phdr_info->dlpi_tls_data = (char *)tls_get_addr_slow(dtvp, 4215 obj->tlsindex, 0, true) + TLS_DTV_OFFSET; 4216 phdr_info->dlpi_adds = obj_loads; 4217 phdr_info->dlpi_subs = obj_loads - obj_count; 4218 } 4219 4220 int 4221 dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param) 4222 { 4223 struct dl_phdr_info phdr_info; 4224 Obj_Entry *obj, marker; 4225 RtldLockState bind_lockstate, phdr_lockstate; 4226 int error; 4227 4228 init_marker(&marker); 4229 error = 0; 4230 4231 wlock_acquire(rtld_phdr_lock, &phdr_lockstate); 4232 wlock_acquire(rtld_bind_lock, &bind_lockstate); 4233 for (obj = globallist_curr(TAILQ_FIRST(&obj_list)); obj != NULL;) { 4234 TAILQ_INSERT_AFTER(&obj_list, obj, &marker, next); 4235 rtld_fill_dl_phdr_info(obj, &phdr_info); 4236 hold_object(obj); 4237 lock_release(rtld_bind_lock, &bind_lockstate); 4238 4239 error = callback(&phdr_info, sizeof phdr_info, param); 4240 4241 wlock_acquire(rtld_bind_lock, &bind_lockstate); 4242 unhold_object(obj); 4243 obj = globallist_next(&marker); 4244 TAILQ_REMOVE(&obj_list, &marker, next); 4245 if (error != 0) { 4246 lock_release(rtld_bind_lock, &bind_lockstate); 4247 lock_release(rtld_phdr_lock, &phdr_lockstate); 4248 return (error); 4249 } 4250 } 4251 4252 if (error == 0) { 4253 rtld_fill_dl_phdr_info(&obj_rtld, &phdr_info); 4254 lock_release(rtld_bind_lock, &bind_lockstate); 4255 error = callback(&phdr_info, sizeof(phdr_info), param); 4256 } 4257 lock_release(rtld_phdr_lock, &phdr_lockstate); 4258 return (error); 4259 } 4260 4261 static void * 4262 fill_search_info(const char *dir, size_t dirlen, void *param) 4263 { 4264 struct fill_search_info_args *arg; 4265 4266 arg = param; 4267 4268 if (arg->request == RTLD_DI_SERINFOSIZE) { 4269 arg->serinfo->dls_cnt ++; 4270 arg->serinfo->dls_size += sizeof(struct dl_serpath) + dirlen + 1; 4271 } else { 4272 struct dl_serpath *s_entry; 4273 4274 s_entry = arg->serpath; 4275 s_entry->dls_name = arg->strspace; 4276 s_entry->dls_flags = arg->flags; 4277 4278 strncpy(arg->strspace, dir, dirlen); 4279 arg->strspace[dirlen] = '\0'; 4280 4281 arg->strspace += dirlen + 1; 4282 arg->serpath++; 4283 } 4284 4285 return (NULL); 4286 } 4287 4288 static int 4289 do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info) 4290 { 4291 struct dl_serinfo _info; 4292 struct fill_search_info_args args; 4293 4294 args.request = RTLD_DI_SERINFOSIZE; 4295 args.serinfo = &_info; 4296 4297 _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 4298 _info.dls_cnt = 0; 4299 4300 path_enumerate(obj->rpath, fill_search_info, NULL, &args); 4301 path_enumerate(ld_library_path, fill_search_info, NULL, &args); 4302 path_enumerate(obj->runpath, fill_search_info, NULL, &args); 4303 path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, &args); 4304 if (!obj->z_nodeflib) 4305 path_enumerate(ld_standard_library_path, fill_search_info, NULL, &args); 4306 4307 4308 if (request == RTLD_DI_SERINFOSIZE) { 4309 info->dls_size = _info.dls_size; 4310 info->dls_cnt = _info.dls_cnt; 4311 return (0); 4312 } 4313 4314 if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) { 4315 _rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()"); 4316 return (-1); 4317 } 4318 4319 args.request = RTLD_DI_SERINFO; 4320 args.serinfo = info; 4321 args.serpath = &info->dls_serpath[0]; 4322 args.strspace = (char *)&info->dls_serpath[_info.dls_cnt]; 4323 4324 args.flags = LA_SER_RUNPATH; 4325 if (path_enumerate(obj->rpath, fill_search_info, NULL, &args) != NULL) 4326 return (-1); 4327 4328 args.flags = LA_SER_LIBPATH; 4329 if (path_enumerate(ld_library_path, fill_search_info, NULL, &args) != NULL) 4330 return (-1); 4331 4332 args.flags = LA_SER_RUNPATH; 4333 if (path_enumerate(obj->runpath, fill_search_info, NULL, &args) != NULL) 4334 return (-1); 4335 4336 args.flags = LA_SER_CONFIG; 4337 if (path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, &args) 4338 != NULL) 4339 return (-1); 4340 4341 args.flags = LA_SER_DEFAULT; 4342 if (!obj->z_nodeflib && path_enumerate(ld_standard_library_path, 4343 fill_search_info, NULL, &args) != NULL) 4344 return (-1); 4345 return (0); 4346 } 4347 4348 static int 4349 rtld_dirname(const char *path, char *bname) 4350 { 4351 const char *endp; 4352 4353 /* Empty or NULL string gets treated as "." */ 4354 if (path == NULL || *path == '\0') { 4355 bname[0] = '.'; 4356 bname[1] = '\0'; 4357 return (0); 4358 } 4359 4360 /* Strip trailing slashes */ 4361 endp = path + strlen(path) - 1; 4362 while (endp > path && *endp == '/') 4363 endp--; 4364 4365 /* Find the start of the dir */ 4366 while (endp > path && *endp != '/') 4367 endp--; 4368 4369 /* Either the dir is "/" or there are no slashes */ 4370 if (endp == path) { 4371 bname[0] = *endp == '/' ? '/' : '.'; 4372 bname[1] = '\0'; 4373 return (0); 4374 } else { 4375 do { 4376 endp--; 4377 } while (endp > path && *endp == '/'); 4378 } 4379 4380 if (endp - path + 2 > PATH_MAX) 4381 { 4382 _rtld_error("Filename is too long: %s", path); 4383 return(-1); 4384 } 4385 4386 strncpy(bname, path, endp - path + 1); 4387 bname[endp - path + 1] = '\0'; 4388 return (0); 4389 } 4390 4391 static int 4392 rtld_dirname_abs(const char *path, char *base) 4393 { 4394 char *last; 4395 4396 if (realpath(path, base) == NULL) { 4397 _rtld_error("realpath \"%s\" failed (%s)", path, 4398 rtld_strerror(errno)); 4399 return (-1); 4400 } 4401 dbg("%s -> %s", path, base); 4402 last = strrchr(base, '/'); 4403 if (last == NULL) { 4404 _rtld_error("non-abs result from realpath \"%s\"", path); 4405 return (-1); 4406 } 4407 if (last != base) 4408 *last = '\0'; 4409 return (0); 4410 } 4411 4412 static void 4413 linkmap_add(Obj_Entry *obj) 4414 { 4415 struct link_map *l, *prev; 4416 4417 l = &obj->linkmap; 4418 l->l_name = obj->path; 4419 l->l_base = obj->mapbase; 4420 l->l_ld = obj->dynamic; 4421 l->l_addr = obj->relocbase; 4422 4423 if (r_debug.r_map == NULL) { 4424 r_debug.r_map = l; 4425 return; 4426 } 4427 4428 /* 4429 * Scan to the end of the list, but not past the entry for the 4430 * dynamic linker, which we want to keep at the very end. 4431 */ 4432 for (prev = r_debug.r_map; 4433 prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap; 4434 prev = prev->l_next) 4435 ; 4436 4437 /* Link in the new entry. */ 4438 l->l_prev = prev; 4439 l->l_next = prev->l_next; 4440 if (l->l_next != NULL) 4441 l->l_next->l_prev = l; 4442 prev->l_next = l; 4443 } 4444 4445 static void 4446 linkmap_delete(Obj_Entry *obj) 4447 { 4448 struct link_map *l; 4449 4450 l = &obj->linkmap; 4451 if (l->l_prev == NULL) { 4452 if ((r_debug.r_map = l->l_next) != NULL) 4453 l->l_next->l_prev = NULL; 4454 return; 4455 } 4456 4457 if ((l->l_prev->l_next = l->l_next) != NULL) 4458 l->l_next->l_prev = l->l_prev; 4459 } 4460 4461 /* 4462 * Function for the debugger to set a breakpoint on to gain control. 4463 * 4464 * The two parameters allow the debugger to easily find and determine 4465 * what the runtime loader is doing and to whom it is doing it. 4466 * 4467 * When the loadhook trap is hit (r_debug_state, set at program 4468 * initialization), the arguments can be found on the stack: 4469 * 4470 * +8 struct link_map *m 4471 * +4 struct r_debug *rd 4472 * +0 RetAddr 4473 */ 4474 void 4475 r_debug_state(struct r_debug* rd __unused, struct link_map *m __unused) 4476 { 4477 /* 4478 * The following is a hack to force the compiler to emit calls to 4479 * this function, even when optimizing. If the function is empty, 4480 * the compiler is not obliged to emit any code for calls to it, 4481 * even when marked __noinline. However, gdb depends on those 4482 * calls being made. 4483 */ 4484 __compiler_membar(); 4485 } 4486 4487 /* 4488 * A function called after init routines have completed. This can be used to 4489 * break before a program's entry routine is called, and can be used when 4490 * main is not available in the symbol table. 4491 */ 4492 void 4493 _r_debug_postinit(struct link_map *m __unused) 4494 { 4495 4496 /* See r_debug_state(). */ 4497 __compiler_membar(); 4498 } 4499 4500 static void 4501 release_object(Obj_Entry *obj) 4502 { 4503 4504 if (obj->holdcount > 0) { 4505 obj->unholdfree = true; 4506 return; 4507 } 4508 munmap(obj->mapbase, obj->mapsize); 4509 linkmap_delete(obj); 4510 obj_free(obj); 4511 } 4512 4513 /* 4514 * Get address of the pointer variable in the main program. 4515 * Prefer non-weak symbol over the weak one. 4516 */ 4517 static const void ** 4518 get_program_var_addr(const char *name, RtldLockState *lockstate) 4519 { 4520 SymLook req; 4521 DoneList donelist; 4522 4523 symlook_init(&req, name); 4524 req.lockstate = lockstate; 4525 donelist_init(&donelist); 4526 if (symlook_global(&req, &donelist) != 0) 4527 return (NULL); 4528 if (ELF_ST_TYPE(req.sym_out->st_info) == STT_FUNC) 4529 return ((const void **)make_function_pointer(req.sym_out, 4530 req.defobj_out)); 4531 else if (ELF_ST_TYPE(req.sym_out->st_info) == STT_GNU_IFUNC) 4532 return ((const void **)rtld_resolve_ifunc(req.defobj_out, req.sym_out)); 4533 else 4534 return ((const void **)(req.defobj_out->relocbase + 4535 req.sym_out->st_value)); 4536 } 4537 4538 /* 4539 * Set a pointer variable in the main program to the given value. This 4540 * is used to set key variables such as "environ" before any of the 4541 * init functions are called. 4542 */ 4543 static void 4544 set_program_var(const char *name, const void *value) 4545 { 4546 const void **addr; 4547 4548 if ((addr = get_program_var_addr(name, NULL)) != NULL) { 4549 dbg("\"%s\": *%p <-- %p", name, addr, value); 4550 *addr = value; 4551 } 4552 } 4553 4554 /* 4555 * Search the global objects, including dependencies and main object, 4556 * for the given symbol. 4557 */ 4558 static int 4559 symlook_global(SymLook *req, DoneList *donelist) 4560 { 4561 SymLook req1; 4562 const Objlist_Entry *elm; 4563 int res; 4564 4565 symlook_init_from_req(&req1, req); 4566 4567 /* Search all objects loaded at program start up. */ 4568 if (req->defobj_out == NULL || (ld_dynamic_weak && 4569 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK)) { 4570 res = symlook_list(&req1, &list_main, donelist); 4571 if (res == 0 && (!ld_dynamic_weak || req->defobj_out == NULL || 4572 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4573 req->sym_out = req1.sym_out; 4574 req->defobj_out = req1.defobj_out; 4575 assert(req->defobj_out != NULL); 4576 } 4577 } 4578 4579 /* Search all DAGs whose roots are RTLD_GLOBAL objects. */ 4580 STAILQ_FOREACH(elm, &list_global, link) { 4581 if (req->defobj_out != NULL && (!ld_dynamic_weak || 4582 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK)) 4583 break; 4584 res = symlook_list(&req1, &elm->obj->dagmembers, donelist); 4585 if (res == 0 && (req->defobj_out == NULL || 4586 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4587 req->sym_out = req1.sym_out; 4588 req->defobj_out = req1.defobj_out; 4589 assert(req->defobj_out != NULL); 4590 } 4591 } 4592 4593 return (req->sym_out != NULL ? 0 : ESRCH); 4594 } 4595 4596 /* 4597 * Given a symbol name in a referencing object, find the corresponding 4598 * definition of the symbol. Returns a pointer to the symbol, or NULL if 4599 * no definition was found. Returns a pointer to the Obj_Entry of the 4600 * defining object via the reference parameter DEFOBJ_OUT. 4601 */ 4602 static int 4603 symlook_default(SymLook *req, const Obj_Entry *refobj) 4604 { 4605 DoneList donelist; 4606 const Objlist_Entry *elm; 4607 SymLook req1; 4608 int res; 4609 4610 donelist_init(&donelist); 4611 symlook_init_from_req(&req1, req); 4612 4613 /* 4614 * Look first in the referencing object if linked symbolically, 4615 * and similarly handle protected symbols. 4616 */ 4617 res = symlook_obj(&req1, refobj); 4618 if (res == 0 && (refobj->symbolic || 4619 ELF_ST_VISIBILITY(req1.sym_out->st_other) == STV_PROTECTED)) { 4620 req->sym_out = req1.sym_out; 4621 req->defobj_out = req1.defobj_out; 4622 assert(req->defobj_out != NULL); 4623 } 4624 if (refobj->symbolic || req->defobj_out != NULL) 4625 donelist_check(&donelist, refobj); 4626 4627 if (!refobj->deepbind) 4628 symlook_global(req, &donelist); 4629 4630 /* Search all dlopened DAGs containing the referencing object. */ 4631 STAILQ_FOREACH(elm, &refobj->dldags, link) { 4632 if (req->sym_out != NULL && (!ld_dynamic_weak || 4633 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK)) 4634 break; 4635 res = symlook_list(&req1, &elm->obj->dagmembers, &donelist); 4636 if (res == 0 && (req->sym_out == NULL || 4637 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4638 req->sym_out = req1.sym_out; 4639 req->defobj_out = req1.defobj_out; 4640 assert(req->defobj_out != NULL); 4641 } 4642 } 4643 4644 if (refobj->deepbind) 4645 symlook_global(req, &donelist); 4646 4647 /* 4648 * Search the dynamic linker itself, and possibly resolve the 4649 * symbol from there. This is how the application links to 4650 * dynamic linker services such as dlopen. 4651 */ 4652 if (req->sym_out == NULL || 4653 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 4654 res = symlook_obj(&req1, &obj_rtld); 4655 if (res == 0) { 4656 req->sym_out = req1.sym_out; 4657 req->defobj_out = req1.defobj_out; 4658 assert(req->defobj_out != NULL); 4659 } 4660 } 4661 4662 return (req->sym_out != NULL ? 0 : ESRCH); 4663 } 4664 4665 static int 4666 symlook_list(SymLook *req, const Objlist *objlist, DoneList *dlp) 4667 { 4668 const Elf_Sym *def; 4669 const Obj_Entry *defobj; 4670 const Objlist_Entry *elm; 4671 SymLook req1; 4672 int res; 4673 4674 def = NULL; 4675 defobj = NULL; 4676 STAILQ_FOREACH(elm, objlist, link) { 4677 if (donelist_check(dlp, elm->obj)) 4678 continue; 4679 symlook_init_from_req(&req1, req); 4680 if ((res = symlook_obj(&req1, elm->obj)) == 0) { 4681 if (def == NULL || (ld_dynamic_weak && 4682 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4683 def = req1.sym_out; 4684 defobj = req1.defobj_out; 4685 if (!ld_dynamic_weak || ELF_ST_BIND(def->st_info) != STB_WEAK) 4686 break; 4687 } 4688 } 4689 } 4690 if (def != NULL) { 4691 req->sym_out = def; 4692 req->defobj_out = defobj; 4693 return (0); 4694 } 4695 return (ESRCH); 4696 } 4697 4698 /* 4699 * Search the chain of DAGS cointed to by the given Needed_Entry 4700 * for a symbol of the given name. Each DAG is scanned completely 4701 * before advancing to the next one. Returns a pointer to the symbol, 4702 * or NULL if no definition was found. 4703 */ 4704 static int 4705 symlook_needed(SymLook *req, const Needed_Entry *needed, DoneList *dlp) 4706 { 4707 const Elf_Sym *def; 4708 const Needed_Entry *n; 4709 const Obj_Entry *defobj; 4710 SymLook req1; 4711 int res; 4712 4713 def = NULL; 4714 defobj = NULL; 4715 symlook_init_from_req(&req1, req); 4716 for (n = needed; n != NULL; n = n->next) { 4717 if (n->obj == NULL || 4718 (res = symlook_list(&req1, &n->obj->dagmembers, dlp)) != 0) 4719 continue; 4720 if (def == NULL || (ld_dynamic_weak && 4721 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4722 def = req1.sym_out; 4723 defobj = req1.defobj_out; 4724 if (!ld_dynamic_weak || ELF_ST_BIND(def->st_info) != STB_WEAK) 4725 break; 4726 } 4727 } 4728 if (def != NULL) { 4729 req->sym_out = def; 4730 req->defobj_out = defobj; 4731 return (0); 4732 } 4733 return (ESRCH); 4734 } 4735 4736 static int 4737 symlook_obj_load_filtees(SymLook *req, SymLook *req1, const Obj_Entry *obj, 4738 Needed_Entry *needed) 4739 { 4740 DoneList donelist; 4741 int flags; 4742 4743 flags = (req->flags & SYMLOOK_EARLY) != 0 ? RTLD_LO_EARLY : 0; 4744 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 4745 donelist_init(&donelist); 4746 symlook_init_from_req(req1, req); 4747 return (symlook_needed(req1, needed, &donelist)); 4748 } 4749 4750 /* 4751 * Search the symbol table of a single shared object for a symbol of 4752 * the given name and version, if requested. Returns a pointer to the 4753 * symbol, or NULL if no definition was found. If the object is 4754 * filter, return filtered symbol from filtee. 4755 * 4756 * The symbol's hash value is passed in for efficiency reasons; that 4757 * eliminates many recomputations of the hash value. 4758 */ 4759 int 4760 symlook_obj(SymLook *req, const Obj_Entry *obj) 4761 { 4762 SymLook req1; 4763 int res, mres; 4764 4765 /* 4766 * If there is at least one valid hash at this point, we prefer to 4767 * use the faster GNU version if available. 4768 */ 4769 if (obj->valid_hash_gnu) 4770 mres = symlook_obj1_gnu(req, obj); 4771 else if (obj->valid_hash_sysv) 4772 mres = symlook_obj1_sysv(req, obj); 4773 else 4774 return (EINVAL); 4775 4776 if (mres == 0) { 4777 if (obj->needed_filtees != NULL) { 4778 res = symlook_obj_load_filtees(req, &req1, obj, 4779 obj->needed_filtees); 4780 if (res == 0) { 4781 req->sym_out = req1.sym_out; 4782 req->defobj_out = req1.defobj_out; 4783 } 4784 return (res); 4785 } 4786 if (obj->needed_aux_filtees != NULL) { 4787 res = symlook_obj_load_filtees(req, &req1, obj, 4788 obj->needed_aux_filtees); 4789 if (res == 0) { 4790 req->sym_out = req1.sym_out; 4791 req->defobj_out = req1.defobj_out; 4792 return (res); 4793 } 4794 } 4795 } 4796 return (mres); 4797 } 4798 4799 /* Symbol match routine common to both hash functions */ 4800 static bool 4801 matched_symbol(SymLook *req, const Obj_Entry *obj, Sym_Match_Result *result, 4802 const unsigned long symnum) 4803 { 4804 Elf_Versym verndx; 4805 const Elf_Sym *symp; 4806 const char *strp; 4807 4808 symp = obj->symtab + symnum; 4809 strp = obj->strtab + symp->st_name; 4810 4811 switch (ELF_ST_TYPE(symp->st_info)) { 4812 case STT_FUNC: 4813 case STT_NOTYPE: 4814 case STT_OBJECT: 4815 case STT_COMMON: 4816 case STT_GNU_IFUNC: 4817 if (symp->st_value == 0) 4818 return (false); 4819 /* fallthrough */ 4820 case STT_TLS: 4821 if (symp->st_shndx != SHN_UNDEF) 4822 break; 4823 else if (((req->flags & SYMLOOK_IN_PLT) == 0) && 4824 (ELF_ST_TYPE(symp->st_info) == STT_FUNC)) 4825 break; 4826 /* fallthrough */ 4827 default: 4828 return (false); 4829 } 4830 if (req->name[0] != strp[0] || strcmp(req->name, strp) != 0) 4831 return (false); 4832 4833 if (req->ventry == NULL) { 4834 if (obj->versyms != NULL) { 4835 verndx = VER_NDX(obj->versyms[symnum]); 4836 if (verndx > obj->vernum) { 4837 _rtld_error( 4838 "%s: symbol %s references wrong version %d", 4839 obj->path, obj->strtab + symnum, verndx); 4840 return (false); 4841 } 4842 /* 4843 * If we are not called from dlsym (i.e. this 4844 * is a normal relocation from unversioned 4845 * binary), accept the symbol immediately if 4846 * it happens to have first version after this 4847 * shared object became versioned. Otherwise, 4848 * if symbol is versioned and not hidden, 4849 * remember it. If it is the only symbol with 4850 * this name exported by the shared object, it 4851 * will be returned as a match by the calling 4852 * function. If symbol is global (verndx < 2) 4853 * accept it unconditionally. 4854 */ 4855 if ((req->flags & SYMLOOK_DLSYM) == 0 && 4856 verndx == VER_NDX_GIVEN) { 4857 result->sym_out = symp; 4858 return (true); 4859 } 4860 else if (verndx >= VER_NDX_GIVEN) { 4861 if ((obj->versyms[symnum] & VER_NDX_HIDDEN) 4862 == 0) { 4863 if (result->vsymp == NULL) 4864 result->vsymp = symp; 4865 result->vcount++; 4866 } 4867 return (false); 4868 } 4869 } 4870 result->sym_out = symp; 4871 return (true); 4872 } 4873 if (obj->versyms == NULL) { 4874 if (object_match_name(obj, req->ventry->name)) { 4875 _rtld_error("%s: object %s should provide version %s " 4876 "for symbol %s", obj_rtld.path, obj->path, 4877 req->ventry->name, obj->strtab + symnum); 4878 return (false); 4879 } 4880 } else { 4881 verndx = VER_NDX(obj->versyms[symnum]); 4882 if (verndx > obj->vernum) { 4883 _rtld_error("%s: symbol %s references wrong version %d", 4884 obj->path, obj->strtab + symnum, verndx); 4885 return (false); 4886 } 4887 if (obj->vertab[verndx].hash != req->ventry->hash || 4888 strcmp(obj->vertab[verndx].name, req->ventry->name)) { 4889 /* 4890 * Version does not match. Look if this is a 4891 * global symbol and if it is not hidden. If 4892 * global symbol (verndx < 2) is available, 4893 * use it. Do not return symbol if we are 4894 * called by dlvsym, because dlvsym looks for 4895 * a specific version and default one is not 4896 * what dlvsym wants. 4897 */ 4898 if ((req->flags & SYMLOOK_DLSYM) || 4899 (verndx >= VER_NDX_GIVEN) || 4900 (obj->versyms[symnum] & VER_NDX_HIDDEN)) 4901 return (false); 4902 } 4903 } 4904 result->sym_out = symp; 4905 return (true); 4906 } 4907 4908 /* 4909 * Search for symbol using SysV hash function. 4910 * obj->buckets is known not to be NULL at this point; the test for this was 4911 * performed with the obj->valid_hash_sysv assignment. 4912 */ 4913 static int 4914 symlook_obj1_sysv(SymLook *req, const Obj_Entry *obj) 4915 { 4916 unsigned long symnum; 4917 Sym_Match_Result matchres; 4918 4919 matchres.sym_out = NULL; 4920 matchres.vsymp = NULL; 4921 matchres.vcount = 0; 4922 4923 for (symnum = obj->buckets[req->hash % obj->nbuckets]; 4924 symnum != STN_UNDEF; symnum = obj->chains[symnum]) { 4925 if (symnum >= obj->nchains) 4926 return (ESRCH); /* Bad object */ 4927 4928 if (matched_symbol(req, obj, &matchres, symnum)) { 4929 req->sym_out = matchres.sym_out; 4930 req->defobj_out = obj; 4931 return (0); 4932 } 4933 } 4934 if (matchres.vcount == 1) { 4935 req->sym_out = matchres.vsymp; 4936 req->defobj_out = obj; 4937 return (0); 4938 } 4939 return (ESRCH); 4940 } 4941 4942 /* Search for symbol using GNU hash function */ 4943 static int 4944 symlook_obj1_gnu(SymLook *req, const Obj_Entry *obj) 4945 { 4946 Elf_Addr bloom_word; 4947 const Elf32_Word *hashval; 4948 Elf32_Word bucket; 4949 Sym_Match_Result matchres; 4950 unsigned int h1, h2; 4951 unsigned long symnum; 4952 4953 matchres.sym_out = NULL; 4954 matchres.vsymp = NULL; 4955 matchres.vcount = 0; 4956 4957 /* Pick right bitmask word from Bloom filter array */ 4958 bloom_word = obj->bloom_gnu[(req->hash_gnu / __ELF_WORD_SIZE) & 4959 obj->maskwords_bm_gnu]; 4960 4961 /* Calculate modulus word size of gnu hash and its derivative */ 4962 h1 = req->hash_gnu & (__ELF_WORD_SIZE - 1); 4963 h2 = ((req->hash_gnu >> obj->shift2_gnu) & (__ELF_WORD_SIZE - 1)); 4964 4965 /* Filter out the "definitely not in set" queries */ 4966 if (((bloom_word >> h1) & (bloom_word >> h2) & 1) == 0) 4967 return (ESRCH); 4968 4969 /* Locate hash chain and corresponding value element*/ 4970 bucket = obj->buckets_gnu[req->hash_gnu % obj->nbuckets_gnu]; 4971 if (bucket == 0) 4972 return (ESRCH); 4973 hashval = &obj->chain_zero_gnu[bucket]; 4974 do { 4975 if (((*hashval ^ req->hash_gnu) >> 1) == 0) { 4976 symnum = hashval - obj->chain_zero_gnu; 4977 if (matched_symbol(req, obj, &matchres, symnum)) { 4978 req->sym_out = matchres.sym_out; 4979 req->defobj_out = obj; 4980 return (0); 4981 } 4982 } 4983 } while ((*hashval++ & 1) == 0); 4984 if (matchres.vcount == 1) { 4985 req->sym_out = matchres.vsymp; 4986 req->defobj_out = obj; 4987 return (0); 4988 } 4989 return (ESRCH); 4990 } 4991 4992 static void 4993 trace_calc_fmts(const char **main_local, const char **fmt1, const char **fmt2) 4994 { 4995 *main_local = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_PROGNAME); 4996 if (*main_local == NULL) 4997 *main_local = ""; 4998 4999 *fmt1 = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_FMT1); 5000 if (*fmt1 == NULL) 5001 *fmt1 = "\t%o => %p (%x)\n"; 5002 5003 *fmt2 = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_FMT2); 5004 if (*fmt2 == NULL) 5005 *fmt2 = "\t%o (%x)\n"; 5006 } 5007 5008 static void 5009 trace_print_obj(Obj_Entry *obj, const char *name, const char *path, 5010 const char *main_local, const char *fmt1, const char *fmt2) 5011 { 5012 const char *fmt; 5013 int c; 5014 5015 if (fmt1 == NULL) 5016 fmt = fmt2; 5017 else 5018 /* XXX bogus */ 5019 fmt = strncmp(name, "lib", 3) == 0 ? fmt1 : fmt2; 5020 5021 while ((c = *fmt++) != '\0') { 5022 switch (c) { 5023 default: 5024 rtld_putchar(c); 5025 continue; 5026 case '\\': 5027 switch (c = *fmt) { 5028 case '\0': 5029 continue; 5030 case 'n': 5031 rtld_putchar('\n'); 5032 break; 5033 case 't': 5034 rtld_putchar('\t'); 5035 break; 5036 } 5037 break; 5038 case '%': 5039 switch (c = *fmt) { 5040 case '\0': 5041 continue; 5042 case '%': 5043 default: 5044 rtld_putchar(c); 5045 break; 5046 case 'A': 5047 rtld_putstr(main_local); 5048 break; 5049 case 'a': 5050 rtld_putstr(obj_main->path); 5051 break; 5052 case 'o': 5053 rtld_putstr(name); 5054 break; 5055 case 'p': 5056 rtld_putstr(path); 5057 break; 5058 case 'x': 5059 rtld_printf("%p", obj != NULL ? 5060 obj->mapbase : NULL); 5061 break; 5062 } 5063 break; 5064 } 5065 ++fmt; 5066 } 5067 } 5068 5069 static void 5070 trace_loaded_objects(Obj_Entry *obj, bool show_preload) 5071 { 5072 const char *fmt1, *fmt2, *main_local; 5073 const char *name, *path; 5074 bool first_spurious, list_containers; 5075 5076 trace_calc_fmts(&main_local, &fmt1, &fmt2); 5077 list_containers = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_ALL) != NULL; 5078 5079 for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 5080 Needed_Entry *needed; 5081 5082 if (obj->marker) 5083 continue; 5084 if (list_containers && obj->needed != NULL) 5085 rtld_printf("%s:\n", obj->path); 5086 for (needed = obj->needed; needed; needed = needed->next) { 5087 if (needed->obj != NULL) { 5088 if (needed->obj->traced && !list_containers) 5089 continue; 5090 needed->obj->traced = true; 5091 path = needed->obj->path; 5092 } else 5093 path = "not found"; 5094 5095 name = obj->strtab + needed->name; 5096 trace_print_obj(needed->obj, name, path, main_local, 5097 fmt1, fmt2); 5098 } 5099 } 5100 5101 if (show_preload) { 5102 if (ld_get_env_var(LD_TRACE_LOADED_OBJECTS_FMT2) == NULL) 5103 fmt2 = "\t%p (%x)\n"; 5104 first_spurious = true; 5105 5106 TAILQ_FOREACH(obj, &obj_list, next) { 5107 if (obj->marker || obj == obj_main || obj->traced) 5108 continue; 5109 5110 if (list_containers && first_spurious) { 5111 rtld_printf("[preloaded]\n"); 5112 first_spurious = false; 5113 } 5114 5115 Name_Entry *fname = STAILQ_FIRST(&obj->names); 5116 name = fname == NULL ? "<unknown>" : fname->name; 5117 trace_print_obj(obj, name, obj->path, main_local, 5118 NULL, fmt2); 5119 } 5120 } 5121 } 5122 5123 /* 5124 * Unload a dlopened object and its dependencies from memory and from 5125 * our data structures. It is assumed that the DAG rooted in the 5126 * object has already been unreferenced, and that the object has a 5127 * reference count of 0. 5128 */ 5129 static void 5130 unload_object(Obj_Entry *root, RtldLockState *lockstate) 5131 { 5132 Obj_Entry marker, *obj, *next; 5133 5134 assert(root->refcount == 0); 5135 5136 /* 5137 * Pass over the DAG removing unreferenced objects from 5138 * appropriate lists. 5139 */ 5140 unlink_object(root); 5141 5142 /* Unmap all objects that are no longer referenced. */ 5143 for (obj = TAILQ_FIRST(&obj_list); obj != NULL; obj = next) { 5144 next = TAILQ_NEXT(obj, next); 5145 if (obj->marker || obj->refcount != 0) 5146 continue; 5147 LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase, 5148 obj->mapsize, 0, obj->path); 5149 dbg("unloading \"%s\"", obj->path); 5150 /* 5151 * Unlink the object now to prevent new references from 5152 * being acquired while the bind lock is dropped in 5153 * recursive dlclose() invocations. 5154 */ 5155 TAILQ_REMOVE(&obj_list, obj, next); 5156 obj_count--; 5157 5158 if (obj->filtees_loaded) { 5159 if (next != NULL) { 5160 init_marker(&marker); 5161 TAILQ_INSERT_BEFORE(next, &marker, next); 5162 unload_filtees(obj, lockstate); 5163 next = TAILQ_NEXT(&marker, next); 5164 TAILQ_REMOVE(&obj_list, &marker, next); 5165 } else 5166 unload_filtees(obj, lockstate); 5167 } 5168 release_object(obj); 5169 } 5170 } 5171 5172 static void 5173 unlink_object(Obj_Entry *root) 5174 { 5175 Objlist_Entry *elm; 5176 5177 if (root->refcount == 0) { 5178 /* Remove the object from the RTLD_GLOBAL list. */ 5179 objlist_remove(&list_global, root); 5180 5181 /* Remove the object from all objects' DAG lists. */ 5182 STAILQ_FOREACH(elm, &root->dagmembers, link) { 5183 objlist_remove(&elm->obj->dldags, root); 5184 if (elm->obj != root) 5185 unlink_object(elm->obj); 5186 } 5187 } 5188 } 5189 5190 static void 5191 ref_dag(Obj_Entry *root) 5192 { 5193 Objlist_Entry *elm; 5194 5195 assert(root->dag_inited); 5196 STAILQ_FOREACH(elm, &root->dagmembers, link) 5197 elm->obj->refcount++; 5198 } 5199 5200 static void 5201 unref_dag(Obj_Entry *root) 5202 { 5203 Objlist_Entry *elm; 5204 5205 assert(root->dag_inited); 5206 STAILQ_FOREACH(elm, &root->dagmembers, link) 5207 elm->obj->refcount--; 5208 } 5209 5210 /* 5211 * Common code for MD __tls_get_addr(). 5212 */ 5213 static void * 5214 tls_get_addr_slow(Elf_Addr **dtvp, int index, size_t offset, bool locked) 5215 { 5216 Elf_Addr *newdtv, *dtv; 5217 RtldLockState lockstate; 5218 int to_copy; 5219 5220 dtv = *dtvp; 5221 /* Check dtv generation in case new modules have arrived */ 5222 if (dtv[0] != tls_dtv_generation) { 5223 if (!locked) 5224 wlock_acquire(rtld_bind_lock, &lockstate); 5225 newdtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 5226 to_copy = dtv[1]; 5227 if (to_copy > tls_max_index) 5228 to_copy = tls_max_index; 5229 memcpy(&newdtv[2], &dtv[2], to_copy * sizeof(Elf_Addr)); 5230 newdtv[0] = tls_dtv_generation; 5231 newdtv[1] = tls_max_index; 5232 free(dtv); 5233 if (!locked) 5234 lock_release(rtld_bind_lock, &lockstate); 5235 dtv = *dtvp = newdtv; 5236 } 5237 5238 /* Dynamically allocate module TLS if necessary */ 5239 if (dtv[index + 1] == 0) { 5240 /* Signal safe, wlock will block out signals. */ 5241 if (!locked) 5242 wlock_acquire(rtld_bind_lock, &lockstate); 5243 if (!dtv[index + 1]) 5244 dtv[index + 1] = (Elf_Addr)allocate_module_tls(index); 5245 if (!locked) 5246 lock_release(rtld_bind_lock, &lockstate); 5247 } 5248 return ((void *)(dtv[index + 1] + offset)); 5249 } 5250 5251 void * 5252 tls_get_addr_common(uintptr_t **dtvp, int index, size_t offset) 5253 { 5254 uintptr_t *dtv; 5255 5256 dtv = *dtvp; 5257 /* Check dtv generation in case new modules have arrived */ 5258 if (__predict_true(dtv[0] == tls_dtv_generation && 5259 dtv[index + 1] != 0)) 5260 return ((void *)(dtv[index + 1] + offset)); 5261 return (tls_get_addr_slow(dtvp, index, offset, false)); 5262 } 5263 5264 #ifdef TLS_VARIANT_I 5265 5266 /* 5267 * Return pointer to allocated TLS block 5268 */ 5269 static void * 5270 get_tls_block_ptr(void *tcb, size_t tcbsize) 5271 { 5272 size_t extra_size, post_size, pre_size, tls_block_size; 5273 size_t tls_init_align; 5274 5275 tls_init_align = MAX(obj_main->tlsalign, 1); 5276 5277 /* Compute fragments sizes. */ 5278 extra_size = tcbsize - TLS_TCB_SIZE; 5279 post_size = calculate_tls_post_size(tls_init_align); 5280 tls_block_size = tcbsize + post_size; 5281 pre_size = roundup2(tls_block_size, tls_init_align) - tls_block_size; 5282 5283 return ((char *)tcb - pre_size - extra_size); 5284 } 5285 5286 /* 5287 * Allocate Static TLS using the Variant I method. 5288 * 5289 * For details on the layout, see lib/libc/gen/tls.c. 5290 * 5291 * NB: rtld's tls_static_space variable includes TLS_TCB_SIZE and post_size as 5292 * it is based on tls_last_offset, and TLS offsets here are really TCB 5293 * offsets, whereas libc's tls_static_space is just the executable's static 5294 * TLS segment. 5295 */ 5296 void * 5297 allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign) 5298 { 5299 Obj_Entry *obj; 5300 char *tls_block; 5301 Elf_Addr *dtv, **tcb; 5302 Elf_Addr addr; 5303 Elf_Addr i; 5304 size_t extra_size, maxalign, post_size, pre_size, tls_block_size; 5305 size_t tls_init_align, tls_init_offset; 5306 5307 if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE) 5308 return (oldtcb); 5309 5310 assert(tcbsize >= TLS_TCB_SIZE); 5311 maxalign = MAX(tcbalign, tls_static_max_align); 5312 tls_init_align = MAX(obj_main->tlsalign, 1); 5313 5314 /* Compute fragmets sizes. */ 5315 extra_size = tcbsize - TLS_TCB_SIZE; 5316 post_size = calculate_tls_post_size(tls_init_align); 5317 tls_block_size = tcbsize + post_size; 5318 pre_size = roundup2(tls_block_size, tls_init_align) - tls_block_size; 5319 tls_block_size += pre_size + tls_static_space - TLS_TCB_SIZE - post_size; 5320 5321 /* Allocate whole TLS block */ 5322 tls_block = xmalloc_aligned(tls_block_size, maxalign, 0); 5323 tcb = (Elf_Addr **)(tls_block + pre_size + extra_size); 5324 5325 if (oldtcb != NULL) { 5326 memcpy(tls_block, get_tls_block_ptr(oldtcb, tcbsize), 5327 tls_static_space); 5328 free(get_tls_block_ptr(oldtcb, tcbsize)); 5329 5330 /* Adjust the DTV. */ 5331 dtv = tcb[0]; 5332 for (i = 0; i < dtv[1]; i++) { 5333 if (dtv[i+2] >= (Elf_Addr)oldtcb && 5334 dtv[i+2] < (Elf_Addr)oldtcb + tls_static_space) { 5335 dtv[i+2] = dtv[i+2] - (Elf_Addr)oldtcb + (Elf_Addr)tcb; 5336 } 5337 } 5338 } else { 5339 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 5340 tcb[0] = dtv; 5341 dtv[0] = tls_dtv_generation; 5342 dtv[1] = tls_max_index; 5343 5344 for (obj = globallist_curr(objs); obj != NULL; 5345 obj = globallist_next(obj)) { 5346 if (obj->tlsoffset == 0) 5347 continue; 5348 tls_init_offset = obj->tlspoffset & (obj->tlsalign - 1); 5349 addr = (Elf_Addr)tcb + obj->tlsoffset; 5350 if (tls_init_offset > 0) 5351 memset((void *)addr, 0, tls_init_offset); 5352 if (obj->tlsinitsize > 0) { 5353 memcpy((void *)(addr + tls_init_offset), obj->tlsinit, 5354 obj->tlsinitsize); 5355 } 5356 if (obj->tlssize > obj->tlsinitsize) { 5357 memset((void *)(addr + tls_init_offset + obj->tlsinitsize), 5358 0, obj->tlssize - obj->tlsinitsize - tls_init_offset); 5359 } 5360 dtv[obj->tlsindex + 1] = addr; 5361 } 5362 } 5363 5364 return (tcb); 5365 } 5366 5367 void 5368 free_tls(void *tcb, size_t tcbsize, size_t tcbalign __unused) 5369 { 5370 Elf_Addr *dtv; 5371 Elf_Addr tlsstart, tlsend; 5372 size_t post_size; 5373 size_t dtvsize, i, tls_init_align __unused; 5374 5375 assert(tcbsize >= TLS_TCB_SIZE); 5376 tls_init_align = MAX(obj_main->tlsalign, 1); 5377 5378 /* Compute fragments sizes. */ 5379 post_size = calculate_tls_post_size(tls_init_align); 5380 5381 tlsstart = (Elf_Addr)tcb + TLS_TCB_SIZE + post_size; 5382 tlsend = (Elf_Addr)tcb + tls_static_space; 5383 5384 dtv = *(Elf_Addr **)tcb; 5385 dtvsize = dtv[1]; 5386 for (i = 0; i < dtvsize; i++) { 5387 if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] >= tlsend)) { 5388 free((void*)dtv[i+2]); 5389 } 5390 } 5391 free(dtv); 5392 free(get_tls_block_ptr(tcb, tcbsize)); 5393 } 5394 5395 #endif /* TLS_VARIANT_I */ 5396 5397 #ifdef TLS_VARIANT_II 5398 5399 /* 5400 * Allocate Static TLS using the Variant II method. 5401 */ 5402 void * 5403 allocate_tls(Obj_Entry *objs, void *oldtls, size_t tcbsize, size_t tcbalign) 5404 { 5405 Obj_Entry *obj; 5406 size_t size, ralign; 5407 char *tls; 5408 Elf_Addr *dtv, *olddtv; 5409 Elf_Addr segbase, oldsegbase, addr; 5410 size_t i; 5411 5412 ralign = tcbalign; 5413 if (tls_static_max_align > ralign) 5414 ralign = tls_static_max_align; 5415 size = roundup(tls_static_space, ralign) + roundup(tcbsize, ralign); 5416 5417 assert(tcbsize >= 2*sizeof(Elf_Addr)); 5418 tls = xmalloc_aligned(size, ralign, 0 /* XXX */); 5419 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 5420 5421 segbase = (Elf_Addr)(tls + roundup(tls_static_space, ralign)); 5422 ((Elf_Addr *)segbase)[0] = segbase; 5423 ((Elf_Addr *)segbase)[1] = (Elf_Addr) dtv; 5424 5425 dtv[0] = tls_dtv_generation; 5426 dtv[1] = tls_max_index; 5427 5428 if (oldtls) { 5429 /* 5430 * Copy the static TLS block over whole. 5431 */ 5432 oldsegbase = (Elf_Addr) oldtls; 5433 memcpy((void *)(segbase - tls_static_space), 5434 (const void *)(oldsegbase - tls_static_space), 5435 tls_static_space); 5436 5437 /* 5438 * If any dynamic TLS blocks have been created tls_get_addr(), 5439 * move them over. 5440 */ 5441 olddtv = ((Elf_Addr **)oldsegbase)[1]; 5442 for (i = 0; i < olddtv[1]; i++) { 5443 if (olddtv[i + 2] < oldsegbase - size || 5444 olddtv[i + 2] > oldsegbase) { 5445 dtv[i + 2] = olddtv[i + 2]; 5446 olddtv[i + 2] = 0; 5447 } 5448 } 5449 5450 /* 5451 * We assume that this block was the one we created with 5452 * allocate_initial_tls(). 5453 */ 5454 free_tls(oldtls, 2 * sizeof(Elf_Addr), sizeof(Elf_Addr)); 5455 } else { 5456 for (obj = objs; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 5457 if (obj->marker || obj->tlsoffset == 0) 5458 continue; 5459 addr = segbase - obj->tlsoffset; 5460 memset((void *)(addr + obj->tlsinitsize), 5461 0, obj->tlssize - obj->tlsinitsize); 5462 if (obj->tlsinit) { 5463 memcpy((void *)addr, obj->tlsinit, obj->tlsinitsize); 5464 obj->static_tls_copied = true; 5465 } 5466 dtv[obj->tlsindex + 1] = addr; 5467 } 5468 } 5469 5470 return ((void *)segbase); 5471 } 5472 5473 void 5474 free_tls(void *tls, size_t tcbsize __unused, size_t tcbalign) 5475 { 5476 Elf_Addr* dtv; 5477 size_t size, ralign; 5478 int dtvsize, i; 5479 Elf_Addr tlsstart, tlsend; 5480 5481 /* 5482 * Figure out the size of the initial TLS block so that we can 5483 * find stuff which ___tls_get_addr() allocated dynamically. 5484 */ 5485 ralign = tcbalign; 5486 if (tls_static_max_align > ralign) 5487 ralign = tls_static_max_align; 5488 size = roundup(tls_static_space, ralign); 5489 5490 dtv = ((Elf_Addr **)tls)[1]; 5491 dtvsize = dtv[1]; 5492 tlsend = (Elf_Addr)tls; 5493 tlsstart = tlsend - size; 5494 for (i = 0; i < dtvsize; i++) { 5495 if (dtv[i + 2] != 0 && (dtv[i + 2] < tlsstart || 5496 dtv[i + 2] > tlsend)) { 5497 free((void *)dtv[i + 2]); 5498 } 5499 } 5500 5501 free((void *)tlsstart); 5502 free((void *)dtv); 5503 } 5504 5505 #endif /* TLS_VARIANT_II */ 5506 5507 /* 5508 * Allocate TLS block for module with given index. 5509 */ 5510 void * 5511 allocate_module_tls(int index) 5512 { 5513 Obj_Entry *obj; 5514 char *p; 5515 5516 TAILQ_FOREACH(obj, &obj_list, next) { 5517 if (obj->marker) 5518 continue; 5519 if (obj->tlsindex == index) 5520 break; 5521 } 5522 if (obj == NULL) { 5523 _rtld_error("Can't find module with TLS index %d", index); 5524 rtld_die(); 5525 } 5526 5527 if (obj->tls_static) { 5528 #ifdef TLS_VARIANT_I 5529 p = (char *)_tcb_get() + obj->tlsoffset + TLS_TCB_SIZE; 5530 #else 5531 p = (char *)_tcb_get() - obj->tlsoffset; 5532 #endif 5533 return (p); 5534 } 5535 5536 obj->tls_dynamic = true; 5537 5538 p = xmalloc_aligned(obj->tlssize, obj->tlsalign, obj->tlspoffset); 5539 memcpy(p, obj->tlsinit, obj->tlsinitsize); 5540 memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize); 5541 return (p); 5542 } 5543 5544 bool 5545 allocate_tls_offset(Obj_Entry *obj) 5546 { 5547 size_t off; 5548 5549 if (obj->tls_dynamic) 5550 return (false); 5551 5552 if (obj->tls_static) 5553 return (true); 5554 5555 if (obj->tlssize == 0) { 5556 obj->tls_static = true; 5557 return (true); 5558 } 5559 5560 if (tls_last_offset == 0) 5561 off = calculate_first_tls_offset(obj->tlssize, obj->tlsalign, 5562 obj->tlspoffset); 5563 else 5564 off = calculate_tls_offset(tls_last_offset, tls_last_size, 5565 obj->tlssize, obj->tlsalign, obj->tlspoffset); 5566 5567 obj->tlsoffset = off; 5568 #ifdef TLS_VARIANT_I 5569 off += obj->tlssize; 5570 #endif 5571 5572 /* 5573 * If we have already fixed the size of the static TLS block, we 5574 * must stay within that size. When allocating the static TLS, we 5575 * leave a small amount of space spare to be used for dynamically 5576 * loading modules which use static TLS. 5577 */ 5578 if (tls_static_space != 0) { 5579 if (off > tls_static_space) 5580 return (false); 5581 } else if (obj->tlsalign > tls_static_max_align) { 5582 tls_static_max_align = obj->tlsalign; 5583 } 5584 5585 tls_last_offset = off; 5586 tls_last_size = obj->tlssize; 5587 obj->tls_static = true; 5588 5589 return (true); 5590 } 5591 5592 void 5593 free_tls_offset(Obj_Entry *obj) 5594 { 5595 5596 /* 5597 * If we were the last thing to allocate out of the static TLS 5598 * block, we give our space back to the 'allocator'. This is a 5599 * simplistic workaround to allow libGL.so.1 to be loaded and 5600 * unloaded multiple times. 5601 */ 5602 size_t off = obj->tlsoffset; 5603 #ifdef TLS_VARIANT_I 5604 off += obj->tlssize; 5605 #endif 5606 if (off == tls_last_offset) { 5607 tls_last_offset -= obj->tlssize; 5608 tls_last_size = 0; 5609 } 5610 } 5611 5612 void * 5613 _rtld_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign) 5614 { 5615 void *ret; 5616 RtldLockState lockstate; 5617 5618 wlock_acquire(rtld_bind_lock, &lockstate); 5619 ret = allocate_tls(globallist_curr(TAILQ_FIRST(&obj_list)), oldtls, 5620 tcbsize, tcbalign); 5621 lock_release(rtld_bind_lock, &lockstate); 5622 return (ret); 5623 } 5624 5625 void 5626 _rtld_free_tls(void *tcb, size_t tcbsize, size_t tcbalign) 5627 { 5628 RtldLockState lockstate; 5629 5630 wlock_acquire(rtld_bind_lock, &lockstate); 5631 free_tls(tcb, tcbsize, tcbalign); 5632 lock_release(rtld_bind_lock, &lockstate); 5633 } 5634 5635 static void 5636 object_add_name(Obj_Entry *obj, const char *name) 5637 { 5638 Name_Entry *entry; 5639 size_t len; 5640 5641 len = strlen(name); 5642 entry = malloc(sizeof(Name_Entry) + len); 5643 5644 if (entry != NULL) { 5645 strcpy(entry->name, name); 5646 STAILQ_INSERT_TAIL(&obj->names, entry, link); 5647 } 5648 } 5649 5650 static int 5651 object_match_name(const Obj_Entry *obj, const char *name) 5652 { 5653 Name_Entry *entry; 5654 5655 STAILQ_FOREACH(entry, &obj->names, link) { 5656 if (strcmp(name, entry->name) == 0) 5657 return (1); 5658 } 5659 return (0); 5660 } 5661 5662 static Obj_Entry * 5663 locate_dependency(const Obj_Entry *obj, const char *name) 5664 { 5665 const Objlist_Entry *entry; 5666 const Needed_Entry *needed; 5667 5668 STAILQ_FOREACH(entry, &list_main, link) { 5669 if (object_match_name(entry->obj, name)) 5670 return (entry->obj); 5671 } 5672 5673 for (needed = obj->needed; needed != NULL; needed = needed->next) { 5674 if (strcmp(obj->strtab + needed->name, name) == 0 || 5675 (needed->obj != NULL && object_match_name(needed->obj, name))) { 5676 /* 5677 * If there is DT_NEEDED for the name we are looking for, 5678 * we are all set. Note that object might not be found if 5679 * dependency was not loaded yet, so the function can 5680 * return NULL here. This is expected and handled 5681 * properly by the caller. 5682 */ 5683 return (needed->obj); 5684 } 5685 } 5686 _rtld_error("%s: Unexpected inconsistency: dependency %s not found", 5687 obj->path, name); 5688 rtld_die(); 5689 } 5690 5691 static int 5692 check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj, 5693 const Elf_Vernaux *vna) 5694 { 5695 const Elf_Verdef *vd; 5696 const char *vername; 5697 5698 vername = refobj->strtab + vna->vna_name; 5699 vd = depobj->verdef; 5700 if (vd == NULL) { 5701 _rtld_error("%s: version %s required by %s not defined", 5702 depobj->path, vername, refobj->path); 5703 return (-1); 5704 } 5705 for (;;) { 5706 if (vd->vd_version != VER_DEF_CURRENT) { 5707 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 5708 depobj->path, vd->vd_version); 5709 return (-1); 5710 } 5711 if (vna->vna_hash == vd->vd_hash) { 5712 const Elf_Verdaux *aux = (const Elf_Verdaux *) 5713 ((const char *)vd + vd->vd_aux); 5714 if (strcmp(vername, depobj->strtab + aux->vda_name) == 0) 5715 return (0); 5716 } 5717 if (vd->vd_next == 0) 5718 break; 5719 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 5720 } 5721 if (vna->vna_flags & VER_FLG_WEAK) 5722 return (0); 5723 _rtld_error("%s: version %s required by %s not found", 5724 depobj->path, vername, refobj->path); 5725 return (-1); 5726 } 5727 5728 static int 5729 rtld_verify_object_versions(Obj_Entry *obj) 5730 { 5731 const Elf_Verneed *vn; 5732 const Elf_Verdef *vd; 5733 const Elf_Verdaux *vda; 5734 const Elf_Vernaux *vna; 5735 const Obj_Entry *depobj; 5736 int maxvernum, vernum; 5737 5738 if (obj->ver_checked) 5739 return (0); 5740 obj->ver_checked = true; 5741 5742 maxvernum = 0; 5743 /* 5744 * Walk over defined and required version records and figure out 5745 * max index used by any of them. Do very basic sanity checking 5746 * while there. 5747 */ 5748 vn = obj->verneed; 5749 while (vn != NULL) { 5750 if (vn->vn_version != VER_NEED_CURRENT) { 5751 _rtld_error("%s: Unsupported version %d of Elf_Verneed entry", 5752 obj->path, vn->vn_version); 5753 return (-1); 5754 } 5755 vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux); 5756 for (;;) { 5757 vernum = VER_NEED_IDX(vna->vna_other); 5758 if (vernum > maxvernum) 5759 maxvernum = vernum; 5760 if (vna->vna_next == 0) 5761 break; 5762 vna = (const Elf_Vernaux *)((const char *)vna + vna->vna_next); 5763 } 5764 if (vn->vn_next == 0) 5765 break; 5766 vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next); 5767 } 5768 5769 vd = obj->verdef; 5770 while (vd != NULL) { 5771 if (vd->vd_version != VER_DEF_CURRENT) { 5772 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 5773 obj->path, vd->vd_version); 5774 return (-1); 5775 } 5776 vernum = VER_DEF_IDX(vd->vd_ndx); 5777 if (vernum > maxvernum) 5778 maxvernum = vernum; 5779 if (vd->vd_next == 0) 5780 break; 5781 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 5782 } 5783 5784 if (maxvernum == 0) 5785 return (0); 5786 5787 /* 5788 * Store version information in array indexable by version index. 5789 * Verify that object version requirements are satisfied along the 5790 * way. 5791 */ 5792 obj->vernum = maxvernum + 1; 5793 obj->vertab = xcalloc(obj->vernum, sizeof(Ver_Entry)); 5794 5795 vd = obj->verdef; 5796 while (vd != NULL) { 5797 if ((vd->vd_flags & VER_FLG_BASE) == 0) { 5798 vernum = VER_DEF_IDX(vd->vd_ndx); 5799 assert(vernum <= maxvernum); 5800 vda = (const Elf_Verdaux *)((const char *)vd + vd->vd_aux); 5801 obj->vertab[vernum].hash = vd->vd_hash; 5802 obj->vertab[vernum].name = obj->strtab + vda->vda_name; 5803 obj->vertab[vernum].file = NULL; 5804 obj->vertab[vernum].flags = 0; 5805 } 5806 if (vd->vd_next == 0) 5807 break; 5808 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 5809 } 5810 5811 vn = obj->verneed; 5812 while (vn != NULL) { 5813 depobj = locate_dependency(obj, obj->strtab + vn->vn_file); 5814 if (depobj == NULL) 5815 return (-1); 5816 vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux); 5817 for (;;) { 5818 if (check_object_provided_version(obj, depobj, vna)) 5819 return (-1); 5820 vernum = VER_NEED_IDX(vna->vna_other); 5821 assert(vernum <= maxvernum); 5822 obj->vertab[vernum].hash = vna->vna_hash; 5823 obj->vertab[vernum].name = obj->strtab + vna->vna_name; 5824 obj->vertab[vernum].file = obj->strtab + vn->vn_file; 5825 obj->vertab[vernum].flags = (vna->vna_other & VER_NEED_HIDDEN) ? 5826 VER_INFO_HIDDEN : 0; 5827 if (vna->vna_next == 0) 5828 break; 5829 vna = (const Elf_Vernaux *)((const char *)vna + vna->vna_next); 5830 } 5831 if (vn->vn_next == 0) 5832 break; 5833 vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next); 5834 } 5835 return (0); 5836 } 5837 5838 static int 5839 rtld_verify_versions(const Objlist *objlist) 5840 { 5841 Objlist_Entry *entry; 5842 int rc; 5843 5844 rc = 0; 5845 STAILQ_FOREACH(entry, objlist, link) { 5846 /* 5847 * Skip dummy objects or objects that have their version requirements 5848 * already checked. 5849 */ 5850 if (entry->obj->strtab == NULL || entry->obj->vertab != NULL) 5851 continue; 5852 if (rtld_verify_object_versions(entry->obj) == -1) { 5853 rc = -1; 5854 if (ld_tracing == NULL) 5855 break; 5856 } 5857 } 5858 if (rc == 0 || ld_tracing != NULL) 5859 rc = rtld_verify_object_versions(&obj_rtld); 5860 return (rc); 5861 } 5862 5863 const Ver_Entry * 5864 fetch_ventry(const Obj_Entry *obj, unsigned long symnum) 5865 { 5866 Elf_Versym vernum; 5867 5868 if (obj->vertab) { 5869 vernum = VER_NDX(obj->versyms[symnum]); 5870 if (vernum >= obj->vernum) { 5871 _rtld_error("%s: symbol %s has wrong verneed value %d", 5872 obj->path, obj->strtab + symnum, vernum); 5873 } else if (obj->vertab[vernum].hash != 0) { 5874 return (&obj->vertab[vernum]); 5875 } 5876 } 5877 return (NULL); 5878 } 5879 5880 int 5881 _rtld_get_stack_prot(void) 5882 { 5883 5884 return (stack_prot); 5885 } 5886 5887 int 5888 _rtld_is_dlopened(void *arg) 5889 { 5890 Obj_Entry *obj; 5891 RtldLockState lockstate; 5892 int res; 5893 5894 rlock_acquire(rtld_bind_lock, &lockstate); 5895 obj = dlcheck(arg); 5896 if (obj == NULL) 5897 obj = obj_from_addr(arg); 5898 if (obj == NULL) { 5899 _rtld_error("No shared object contains address"); 5900 lock_release(rtld_bind_lock, &lockstate); 5901 return (-1); 5902 } 5903 res = obj->dlopened ? 1 : 0; 5904 lock_release(rtld_bind_lock, &lockstate); 5905 return (res); 5906 } 5907 5908 static int 5909 obj_remap_relro(Obj_Entry *obj, int prot) 5910 { 5911 5912 if (obj->relro_size > 0 && mprotect(obj->relro_page, obj->relro_size, 5913 prot) == -1) { 5914 _rtld_error("%s: Cannot set relro protection to %#x: %s", 5915 obj->path, prot, rtld_strerror(errno)); 5916 return (-1); 5917 } 5918 return (0); 5919 } 5920 5921 static int 5922 obj_disable_relro(Obj_Entry *obj) 5923 { 5924 5925 return (obj_remap_relro(obj, PROT_READ | PROT_WRITE)); 5926 } 5927 5928 static int 5929 obj_enforce_relro(Obj_Entry *obj) 5930 { 5931 5932 return (obj_remap_relro(obj, PROT_READ)); 5933 } 5934 5935 static void 5936 map_stacks_exec(RtldLockState *lockstate) 5937 { 5938 void (*thr_map_stacks_exec)(void); 5939 5940 if ((max_stack_flags & PF_X) == 0 || (stack_prot & PROT_EXEC) != 0) 5941 return; 5942 thr_map_stacks_exec = (void (*)(void))(uintptr_t) 5943 get_program_var_addr("__pthread_map_stacks_exec", lockstate); 5944 if (thr_map_stacks_exec != NULL) { 5945 stack_prot |= PROT_EXEC; 5946 thr_map_stacks_exec(); 5947 } 5948 } 5949 5950 static void 5951 distribute_static_tls(Objlist *list, RtldLockState *lockstate) 5952 { 5953 Objlist_Entry *elm; 5954 Obj_Entry *obj; 5955 void (*distrib)(size_t, void *, size_t, size_t); 5956 5957 distrib = (void (*)(size_t, void *, size_t, size_t))(uintptr_t) 5958 get_program_var_addr("__pthread_distribute_static_tls", lockstate); 5959 if (distrib == NULL) 5960 return; 5961 STAILQ_FOREACH(elm, list, link) { 5962 obj = elm->obj; 5963 if (obj->marker || !obj->tls_static || obj->static_tls_copied) 5964 continue; 5965 lock_release(rtld_bind_lock, lockstate); 5966 distrib(obj->tlsoffset, obj->tlsinit, obj->tlsinitsize, 5967 obj->tlssize); 5968 wlock_acquire(rtld_bind_lock, lockstate); 5969 obj->static_tls_copied = true; 5970 } 5971 } 5972 5973 void 5974 symlook_init(SymLook *dst, const char *name) 5975 { 5976 5977 bzero(dst, sizeof(*dst)); 5978 dst->name = name; 5979 dst->hash = elf_hash(name); 5980 dst->hash_gnu = gnu_hash(name); 5981 } 5982 5983 static void 5984 symlook_init_from_req(SymLook *dst, const SymLook *src) 5985 { 5986 5987 dst->name = src->name; 5988 dst->hash = src->hash; 5989 dst->hash_gnu = src->hash_gnu; 5990 dst->ventry = src->ventry; 5991 dst->flags = src->flags; 5992 dst->defobj_out = NULL; 5993 dst->sym_out = NULL; 5994 dst->lockstate = src->lockstate; 5995 } 5996 5997 static int 5998 open_binary_fd(const char *argv0, bool search_in_path, 5999 const char **binpath_res) 6000 { 6001 char *binpath, *pathenv, *pe, *res1; 6002 const char *res; 6003 int fd; 6004 6005 binpath = NULL; 6006 res = NULL; 6007 if (search_in_path && strchr(argv0, '/') == NULL) { 6008 binpath = xmalloc(PATH_MAX); 6009 pathenv = getenv("PATH"); 6010 if (pathenv == NULL) { 6011 _rtld_error("-p and no PATH environment variable"); 6012 rtld_die(); 6013 } 6014 pathenv = strdup(pathenv); 6015 if (pathenv == NULL) { 6016 _rtld_error("Cannot allocate memory"); 6017 rtld_die(); 6018 } 6019 fd = -1; 6020 errno = ENOENT; 6021 while ((pe = strsep(&pathenv, ":")) != NULL) { 6022 if (strlcpy(binpath, pe, PATH_MAX) >= PATH_MAX) 6023 continue; 6024 if (binpath[0] != '\0' && 6025 strlcat(binpath, "/", PATH_MAX) >= PATH_MAX) 6026 continue; 6027 if (strlcat(binpath, argv0, PATH_MAX) >= PATH_MAX) 6028 continue; 6029 fd = open(binpath, O_RDONLY | O_CLOEXEC | O_VERIFY); 6030 if (fd != -1 || errno != ENOENT) { 6031 res = binpath; 6032 break; 6033 } 6034 } 6035 free(pathenv); 6036 } else { 6037 fd = open(argv0, O_RDONLY | O_CLOEXEC | O_VERIFY); 6038 res = argv0; 6039 } 6040 6041 if (fd == -1) { 6042 _rtld_error("Cannot open %s: %s", argv0, rtld_strerror(errno)); 6043 rtld_die(); 6044 } 6045 if (res != NULL && res[0] != '/') { 6046 res1 = xmalloc(PATH_MAX); 6047 if (realpath(res, res1) != NULL) { 6048 if (res != argv0) 6049 free(__DECONST(char *, res)); 6050 res = res1; 6051 } else { 6052 free(res1); 6053 } 6054 } 6055 *binpath_res = res; 6056 return (fd); 6057 } 6058 6059 /* 6060 * Parse a set of command-line arguments. 6061 */ 6062 static int 6063 parse_args(char* argv[], int argc, bool *use_pathp, int *fdp, 6064 const char **argv0, bool *dir_ignore) 6065 { 6066 const char *arg; 6067 char machine[64]; 6068 size_t sz; 6069 int arglen, fd, i, j, mib[2]; 6070 char opt; 6071 bool seen_b, seen_f; 6072 6073 dbg("Parsing command-line arguments"); 6074 *use_pathp = false; 6075 *fdp = -1; 6076 *dir_ignore = false; 6077 seen_b = seen_f = false; 6078 6079 for (i = 1; i < argc; i++ ) { 6080 arg = argv[i]; 6081 dbg("argv[%d]: '%s'", i, arg); 6082 6083 /* 6084 * rtld arguments end with an explicit "--" or with the first 6085 * non-prefixed argument. 6086 */ 6087 if (strcmp(arg, "--") == 0) { 6088 i++; 6089 break; 6090 } 6091 if (arg[0] != '-') 6092 break; 6093 6094 /* 6095 * All other arguments are single-character options that can 6096 * be combined, so we need to search through `arg` for them. 6097 */ 6098 arglen = strlen(arg); 6099 for (j = 1; j < arglen; j++) { 6100 opt = arg[j]; 6101 if (opt == 'h') { 6102 print_usage(argv[0]); 6103 _exit(0); 6104 } else if (opt == 'b') { 6105 if (seen_f) { 6106 _rtld_error("Both -b and -f specified"); 6107 rtld_die(); 6108 } 6109 if (j != arglen - 1) { 6110 _rtld_error("Invalid options: %s", arg); 6111 rtld_die(); 6112 } 6113 i++; 6114 *argv0 = argv[i]; 6115 seen_b = true; 6116 break; 6117 } else if (opt == 'd') { 6118 *dir_ignore = true; 6119 } else if (opt == 'f') { 6120 if (seen_b) { 6121 _rtld_error("Both -b and -f specified"); 6122 rtld_die(); 6123 } 6124 6125 /* 6126 * -f XX can be used to specify a 6127 * descriptor for the binary named at 6128 * the command line (i.e., the later 6129 * argument will specify the process 6130 * name but the descriptor is what 6131 * will actually be executed). 6132 * 6133 * -f must be the last option in the 6134 * group, e.g., -abcf <fd>. 6135 */ 6136 if (j != arglen - 1) { 6137 _rtld_error("Invalid options: %s", arg); 6138 rtld_die(); 6139 } 6140 i++; 6141 fd = parse_integer(argv[i]); 6142 if (fd == -1) { 6143 _rtld_error( 6144 "Invalid file descriptor: '%s'", 6145 argv[i]); 6146 rtld_die(); 6147 } 6148 *fdp = fd; 6149 seen_f = true; 6150 break; 6151 } else if (opt == 'o') { 6152 struct ld_env_var_desc *l; 6153 char *n, *v; 6154 u_int ll; 6155 6156 if (j != arglen - 1) { 6157 _rtld_error("Invalid options: %s", arg); 6158 rtld_die(); 6159 } 6160 i++; 6161 n = argv[i]; 6162 v = strchr(n, '='); 6163 if (v == NULL) { 6164 _rtld_error("No '=' in -o parameter"); 6165 rtld_die(); 6166 } 6167 for (ll = 0; ll < nitems(ld_env_vars); ll++) { 6168 l = &ld_env_vars[ll]; 6169 if (v - n == (ptrdiff_t)strlen(l->n) && 6170 strncmp(n, l->n, v - n) == 0) { 6171 l->val = v + 1; 6172 break; 6173 } 6174 } 6175 if (ll == nitems(ld_env_vars)) { 6176 _rtld_error("Unknown LD_ option %s", 6177 n); 6178 rtld_die(); 6179 } 6180 } else if (opt == 'p') { 6181 *use_pathp = true; 6182 } else if (opt == 'u') { 6183 u_int ll; 6184 6185 for (ll = 0; ll < nitems(ld_env_vars); ll++) 6186 ld_env_vars[ll].val = NULL; 6187 } else if (opt == 'v') { 6188 machine[0] = '\0'; 6189 mib[0] = CTL_HW; 6190 mib[1] = HW_MACHINE; 6191 sz = sizeof(machine); 6192 sysctl(mib, nitems(mib), machine, &sz, NULL, 0); 6193 ld_elf_hints_path = ld_get_env_var( 6194 LD_ELF_HINTS_PATH); 6195 set_ld_elf_hints_path(); 6196 rtld_printf( 6197 "FreeBSD ld-elf.so.1 %s\n" 6198 "FreeBSD_version %d\n" 6199 "Default lib path %s\n" 6200 "Hints lib path %s\n" 6201 "Env prefix %s\n" 6202 "Default hint file %s\n" 6203 "Hint file %s\n" 6204 "libmap file %s\n" 6205 "Optional static TLS size %zd bytes\n", 6206 machine, 6207 __FreeBSD_version, ld_standard_library_path, 6208 gethints(false), 6209 ld_env_prefix, ld_elf_hints_default, 6210 ld_elf_hints_path, 6211 ld_path_libmap_conf, 6212 ld_static_tls_extra); 6213 _exit(0); 6214 } else { 6215 _rtld_error("Invalid argument: '%s'", arg); 6216 print_usage(argv[0]); 6217 rtld_die(); 6218 } 6219 } 6220 } 6221 6222 if (!seen_b) 6223 *argv0 = argv[i]; 6224 return (i); 6225 } 6226 6227 /* 6228 * Parse a file descriptor number without pulling in more of libc (e.g. atoi). 6229 */ 6230 static int 6231 parse_integer(const char *str) 6232 { 6233 static const int RADIX = 10; /* XXXJA: possibly support hex? */ 6234 const char *orig; 6235 int n; 6236 char c; 6237 6238 orig = str; 6239 n = 0; 6240 for (c = *str; c != '\0'; c = *++str) { 6241 if (c < '0' || c > '9') 6242 return (-1); 6243 6244 n *= RADIX; 6245 n += c - '0'; 6246 } 6247 6248 /* Make sure we actually parsed something. */ 6249 if (str == orig) 6250 return (-1); 6251 return (n); 6252 } 6253 6254 static void 6255 print_usage(const char *argv0) 6256 { 6257 6258 rtld_printf( 6259 "Usage: %s [-h] [-b <exe>] [-d] [-f <FD>] [-p] [--] <binary> [<args>]\n" 6260 "\n" 6261 "Options:\n" 6262 " -h Display this help message\n" 6263 " -b <exe> Execute <exe> instead of <binary>, arg0 is <binary>\n" 6264 " -d Ignore lack of exec permissions for the binary\n" 6265 " -f <FD> Execute <FD> instead of searching for <binary>\n" 6266 " -o <OPT>=<VAL> Set LD_<OPT> to <VAL>, without polluting env\n" 6267 " -p Search in PATH for named binary\n" 6268 " -u Ignore LD_ environment variables\n" 6269 " -v Display identification information\n" 6270 " -- End of RTLD options\n" 6271 " <binary> Name of process to execute\n" 6272 " <args> Arguments to the executed process\n", argv0); 6273 } 6274 6275 #define AUXFMT(at, xfmt) [at] = { .name = #at, .fmt = xfmt } 6276 static const struct auxfmt { 6277 const char *name; 6278 const char *fmt; 6279 } auxfmts[] = { 6280 AUXFMT(AT_NULL, NULL), 6281 AUXFMT(AT_IGNORE, NULL), 6282 AUXFMT(AT_EXECFD, "%ld"), 6283 AUXFMT(AT_PHDR, "%p"), 6284 AUXFMT(AT_PHENT, "%lu"), 6285 AUXFMT(AT_PHNUM, "%lu"), 6286 AUXFMT(AT_PAGESZ, "%lu"), 6287 AUXFMT(AT_BASE, "%#lx"), 6288 AUXFMT(AT_FLAGS, "%#lx"), 6289 AUXFMT(AT_ENTRY, "%p"), 6290 AUXFMT(AT_NOTELF, NULL), 6291 AUXFMT(AT_UID, "%ld"), 6292 AUXFMT(AT_EUID, "%ld"), 6293 AUXFMT(AT_GID, "%ld"), 6294 AUXFMT(AT_EGID, "%ld"), 6295 AUXFMT(AT_EXECPATH, "%s"), 6296 AUXFMT(AT_CANARY, "%p"), 6297 AUXFMT(AT_CANARYLEN, "%lu"), 6298 AUXFMT(AT_OSRELDATE, "%lu"), 6299 AUXFMT(AT_NCPUS, "%lu"), 6300 AUXFMT(AT_PAGESIZES, "%p"), 6301 AUXFMT(AT_PAGESIZESLEN, "%lu"), 6302 AUXFMT(AT_TIMEKEEP, "%p"), 6303 AUXFMT(AT_STACKPROT, "%#lx"), 6304 AUXFMT(AT_EHDRFLAGS, "%#lx"), 6305 AUXFMT(AT_HWCAP, "%#lx"), 6306 AUXFMT(AT_HWCAP2, "%#lx"), 6307 AUXFMT(AT_BSDFLAGS, "%#lx"), 6308 AUXFMT(AT_ARGC, "%lu"), 6309 AUXFMT(AT_ARGV, "%p"), 6310 AUXFMT(AT_ENVC, "%p"), 6311 AUXFMT(AT_ENVV, "%p"), 6312 AUXFMT(AT_PS_STRINGS, "%p"), 6313 AUXFMT(AT_FXRNG, "%p"), 6314 AUXFMT(AT_KPRELOAD, "%p"), 6315 AUXFMT(AT_USRSTACKBASE, "%#lx"), 6316 AUXFMT(AT_USRSTACKLIM, "%#lx"), 6317 }; 6318 6319 static bool 6320 is_ptr_fmt(const char *fmt) 6321 { 6322 char last; 6323 6324 last = fmt[strlen(fmt) - 1]; 6325 return (last == 'p' || last == 's'); 6326 } 6327 6328 static void 6329 dump_auxv(Elf_Auxinfo **aux_info) 6330 { 6331 Elf_Auxinfo *auxp; 6332 const struct auxfmt *fmt; 6333 int i; 6334 6335 for (i = 0; i < AT_COUNT; i++) { 6336 auxp = aux_info[i]; 6337 if (auxp == NULL) 6338 continue; 6339 fmt = &auxfmts[i]; 6340 if (fmt->fmt == NULL) 6341 continue; 6342 rtld_fdprintf(STDOUT_FILENO, "%s:\t", fmt->name); 6343 if (is_ptr_fmt(fmt->fmt)) { 6344 rtld_fdprintfx(STDOUT_FILENO, fmt->fmt, 6345 auxp->a_un.a_ptr); 6346 } else { 6347 rtld_fdprintfx(STDOUT_FILENO, fmt->fmt, 6348 auxp->a_un.a_val); 6349 } 6350 rtld_fdprintf(STDOUT_FILENO, "\n"); 6351 } 6352 } 6353 6354 /* 6355 * Overrides for libc_pic-provided functions. 6356 */ 6357 6358 int 6359 __getosreldate(void) 6360 { 6361 size_t len; 6362 int oid[2]; 6363 int error, osrel; 6364 6365 if (osreldate != 0) 6366 return (osreldate); 6367 6368 oid[0] = CTL_KERN; 6369 oid[1] = KERN_OSRELDATE; 6370 osrel = 0; 6371 len = sizeof(osrel); 6372 error = sysctl(oid, 2, &osrel, &len, NULL, 0); 6373 if (error == 0 && osrel > 0 && len == sizeof(osrel)) 6374 osreldate = osrel; 6375 return (osreldate); 6376 } 6377 const char * 6378 rtld_strerror(int errnum) 6379 { 6380 6381 if (errnum < 0 || errnum >= sys_nerr) 6382 return ("Unknown error"); 6383 return (sys_errlist[errnum]); 6384 } 6385 6386 char * 6387 getenv(const char *name) 6388 { 6389 return (__DECONST(char *, rtld_get_env_val(environ, name, 6390 strlen(name)))); 6391 } 6392 6393 /* malloc */ 6394 void * 6395 malloc(size_t nbytes) 6396 { 6397 6398 return (__crt_malloc(nbytes)); 6399 } 6400 6401 void * 6402 calloc(size_t num, size_t size) 6403 { 6404 6405 return (__crt_calloc(num, size)); 6406 } 6407 6408 void 6409 free(void *cp) 6410 { 6411 6412 __crt_free(cp); 6413 } 6414 6415 void * 6416 realloc(void *cp, size_t nbytes) 6417 { 6418 6419 return (__crt_realloc(cp, nbytes)); 6420 } 6421 6422 extern int _rtld_version__FreeBSD_version __exported; 6423 int _rtld_version__FreeBSD_version = __FreeBSD_version; 6424 6425 extern char _rtld_version_laddr_offset __exported; 6426 char _rtld_version_laddr_offset; 6427 6428 extern char _rtld_version_dlpi_tls_data __exported; 6429 char _rtld_version_dlpi_tls_data; 6430