1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright 1996, 1997, 1998, 1999, 2000 John D. Polstra. 5 * Copyright 2003 Alexander Kabaev <[email protected]>. 6 * Copyright 2009-2013 Konstantin Belousov <[email protected]>. 7 * Copyright 2012 John Marino <[email protected]>. 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 <[email protected]>. 39 */ 40 41 #include <sys/cdefs.h> 42 #include <sys/param.h> 43 #include <sys/mount.h> 44 #include <sys/mman.h> 45 #include <sys/stat.h> 46 #include <sys/sysctl.h> 47 #include <sys/uio.h> 48 #include <sys/utsname.h> 49 #include <sys/ktrace.h> 50 51 #include <dlfcn.h> 52 #include <err.h> 53 #include <errno.h> 54 #include <fcntl.h> 55 #include <stdarg.h> 56 #include <stdio.h> 57 #include <stdlib.h> 58 #include <string.h> 59 #include <unistd.h> 60 61 #include "debug.h" 62 #include "rtld.h" 63 #include "libmap.h" 64 #include "rtld_paths.h" 65 #include "rtld_tls.h" 66 #include "rtld_printf.h" 67 #include "rtld_malloc.h" 68 #include "rtld_utrace.h" 69 #include "notes.h" 70 #include "rtld_libc.h" 71 72 /* Types. */ 73 typedef void (*func_ptr_type)(void); 74 typedef void * (*path_enum_proc) (const char *path, size_t len, void *arg); 75 76 77 /* Variables that cannot be static: */ 78 extern struct r_debug r_debug; /* For GDB */ 79 extern int _thread_autoinit_dummy_decl; 80 extern void (*__cleanup)(void); 81 82 struct dlerror_save { 83 int seen; 84 char *msg; 85 }; 86 87 /* 88 * Function declarations. 89 */ 90 static const char *basename(const char *); 91 static void digest_dynamic1(Obj_Entry *, int, const Elf_Dyn **, 92 const Elf_Dyn **, const Elf_Dyn **); 93 static bool digest_dynamic2(Obj_Entry *, const Elf_Dyn *, const Elf_Dyn *, 94 const Elf_Dyn *); 95 static bool digest_dynamic(Obj_Entry *, int); 96 static Obj_Entry *digest_phdr(const Elf_Phdr *, int, caddr_t, const char *); 97 static void distribute_static_tls(Objlist *, RtldLockState *); 98 static Obj_Entry *dlcheck(void *); 99 static int dlclose_locked(void *, RtldLockState *); 100 static Obj_Entry *dlopen_object(const char *name, int fd, Obj_Entry *refobj, 101 int lo_flags, int mode, RtldLockState *lockstate); 102 static Obj_Entry *do_load_object(int, const char *, char *, struct stat *, int); 103 static int do_search_info(const Obj_Entry *obj, int, struct dl_serinfo *); 104 static bool donelist_check(DoneList *, const Obj_Entry *); 105 static void dump_auxv(Elf_Auxinfo **aux_info); 106 static void errmsg_restore(struct dlerror_save *); 107 static struct dlerror_save *errmsg_save(void); 108 static void *fill_search_info(const char *, size_t, void *); 109 static char *find_library(const char *, const Obj_Entry *, int *); 110 static const char *gethints(bool); 111 static void hold_object(Obj_Entry *); 112 static void unhold_object(Obj_Entry *); 113 static void init_dag(Obj_Entry *); 114 static void init_marker(Obj_Entry *); 115 static void init_pagesizes(Elf_Auxinfo **aux_info); 116 static void init_rtld(caddr_t, Elf_Auxinfo **); 117 static void initlist_add_neededs(Needed_Entry *, Objlist *); 118 static void initlist_add_objects(Obj_Entry *, Obj_Entry *, Objlist *); 119 static int initlist_objects_ifunc(Objlist *, bool, int, RtldLockState *); 120 static void linkmap_add(Obj_Entry *); 121 static void linkmap_delete(Obj_Entry *); 122 static void load_filtees(Obj_Entry *, int flags, RtldLockState *); 123 static void unload_filtees(Obj_Entry *, RtldLockState *); 124 static int load_needed_objects(Obj_Entry *, int); 125 static int load_preload_objects(const char *, bool); 126 static int load_kpreload(const void *addr); 127 static Obj_Entry *load_object(const char *, int fd, const Obj_Entry *, int); 128 static void map_stacks_exec(RtldLockState *); 129 static int obj_disable_relro(Obj_Entry *); 130 static int obj_enforce_relro(Obj_Entry *); 131 static void objlist_call_fini(Objlist *, Obj_Entry *, RtldLockState *); 132 static void objlist_call_init(Objlist *, RtldLockState *); 133 static void objlist_clear(Objlist *); 134 static Objlist_Entry *objlist_find(Objlist *, const Obj_Entry *); 135 static void objlist_init(Objlist *); 136 static void objlist_push_head(Objlist *, Obj_Entry *); 137 static void objlist_push_tail(Objlist *, Obj_Entry *); 138 static void objlist_put_after(Objlist *, Obj_Entry *, Obj_Entry *); 139 static void objlist_remove(Objlist *, Obj_Entry *); 140 static int open_binary_fd(const char *argv0, bool search_in_path, 141 const char **binpath_res); 142 static int parse_args(char* argv[], int argc, bool *use_pathp, int *fdp, 143 const char **argv0, bool *dir_ignore); 144 static int parse_integer(const char *); 145 static void *path_enumerate(const char *, path_enum_proc, const char *, void *); 146 static void print_usage(const char *argv0); 147 static void release_object(Obj_Entry *); 148 static int relocate_object_dag(Obj_Entry *root, bool bind_now, 149 Obj_Entry *rtldobj, int flags, RtldLockState *lockstate); 150 static int relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, 151 int flags, RtldLockState *lockstate); 152 static int relocate_objects(Obj_Entry *, bool, Obj_Entry *, int, 153 RtldLockState *); 154 static int resolve_object_ifunc(Obj_Entry *, bool, int, RtldLockState *); 155 static int rtld_dirname(const char *, char *); 156 static int rtld_dirname_abs(const char *, char *); 157 static void *rtld_dlopen(const char *name, int fd, int mode); 158 static void rtld_exit(void); 159 static void rtld_nop_exit(void); 160 static char *search_library_path(const char *, const char *, const char *, 161 int *); 162 static char *search_library_pathfds(const char *, const char *, int *); 163 static const void **get_program_var_addr(const char *, RtldLockState *); 164 static void set_program_var(const char *, const void *); 165 static int symlook_default(SymLook *, const Obj_Entry *refobj); 166 static int symlook_global(SymLook *, DoneList *); 167 static void symlook_init_from_req(SymLook *, const SymLook *); 168 static int symlook_list(SymLook *, const Objlist *, DoneList *); 169 static int symlook_needed(SymLook *, const Needed_Entry *, DoneList *); 170 static int symlook_obj1_sysv(SymLook *, const Obj_Entry *); 171 static int symlook_obj1_gnu(SymLook *, const Obj_Entry *); 172 static void *tls_get_addr_slow(Elf_Addr **, int, size_t, bool) __noinline; 173 static void trace_loaded_objects(Obj_Entry *, bool); 174 static void unlink_object(Obj_Entry *); 175 static void unload_object(Obj_Entry *, RtldLockState *lockstate); 176 static void unref_dag(Obj_Entry *); 177 static void ref_dag(Obj_Entry *); 178 static char *origin_subst_one(Obj_Entry *, char *, const char *, 179 const char *, bool); 180 static char *origin_subst(Obj_Entry *, const char *); 181 static bool obj_resolve_origin(Obj_Entry *obj); 182 static void preinit_main(void); 183 static int rtld_verify_versions(const Objlist *); 184 static int rtld_verify_object_versions(Obj_Entry *); 185 static void object_add_name(Obj_Entry *, const char *); 186 static int object_match_name(const Obj_Entry *, const char *); 187 static void ld_utrace_log(int, void *, void *, size_t, int, const char *); 188 static void rtld_fill_dl_phdr_info(const Obj_Entry *obj, 189 struct dl_phdr_info *phdr_info); 190 static uint32_t gnu_hash(const char *); 191 static bool matched_symbol(SymLook *, const Obj_Entry *, Sym_Match_Result *, 192 const unsigned long); 193 194 void r_debug_state(struct r_debug *, struct link_map *) __noinline __exported; 195 void _r_debug_postinit(struct link_map *) __noinline __exported; 196 197 int __sys_openat(int, const char *, int, ...); 198 199 /* 200 * Data declarations. 201 */ 202 struct r_debug r_debug __exported; /* for GDB; */ 203 static bool libmap_disable; /* Disable libmap */ 204 static bool ld_loadfltr; /* Immediate filters processing */ 205 static const char *libmap_override;/* Maps to use in addition to libmap.conf */ 206 static bool trust; /* False for setuid and setgid programs */ 207 static bool dangerous_ld_env; /* True if environment variables have been 208 used to affect the libraries loaded */ 209 bool ld_bind_not; /* Disable PLT update */ 210 static const char *ld_bind_now; /* Environment variable for immediate binding */ 211 static const char *ld_debug; /* Environment variable for debugging */ 212 static bool ld_dynamic_weak = true; /* True if non-weak definition overrides 213 weak definition */ 214 static const char *ld_library_path;/* Environment variable for search path */ 215 static const char *ld_library_dirs;/* Environment variable for library descriptors */ 216 static const char *ld_preload; /* Environment variable for libraries to 217 load first */ 218 static const char *ld_preload_fds;/* Environment variable for libraries represented by 219 descriptors */ 220 static const char *ld_elf_hints_path; /* Environment variable for alternative hints path */ 221 static const char *ld_tracing; /* Called from ldd to print libs */ 222 static const char *ld_utrace; /* Use utrace() to log events. */ 223 static struct obj_entry_q obj_list; /* Queue of all loaded objects */ 224 static Obj_Entry *obj_main; /* The main program shared object */ 225 static Obj_Entry obj_rtld; /* The dynamic linker shared object */ 226 static unsigned int obj_count; /* Number of objects in obj_list */ 227 static unsigned int obj_loads; /* Number of loads of objects (gen count) */ 228 229 static Objlist list_global = /* Objects dlopened with RTLD_GLOBAL */ 230 STAILQ_HEAD_INITIALIZER(list_global); 231 static Objlist list_main = /* Objects loaded at program startup */ 232 STAILQ_HEAD_INITIALIZER(list_main); 233 static Objlist list_fini = /* Objects needing fini() calls */ 234 STAILQ_HEAD_INITIALIZER(list_fini); 235 236 Elf_Sym sym_zero; /* For resolving undefined weak refs. */ 237 238 #define GDB_STATE(s,m) r_debug.r_state = s; r_debug_state(&r_debug,m); 239 240 extern Elf_Dyn _DYNAMIC; 241 #pragma weak _DYNAMIC 242 243 int dlclose(void *) __exported; 244 char *dlerror(void) __exported; 245 void *dlopen(const char *, int) __exported; 246 void *fdlopen(int, int) __exported; 247 void *dlsym(void *, const char *) __exported; 248 dlfunc_t dlfunc(void *, const char *) __exported; 249 void *dlvsym(void *, const char *, const char *) __exported; 250 int dladdr(const void *, Dl_info *) __exported; 251 void dllockinit(void *, void *(*)(void *), void (*)(void *), void (*)(void *), 252 void (*)(void *), void (*)(void *), void (*)(void *)) __exported; 253 int dlinfo(void *, int , void *) __exported; 254 int dl_iterate_phdr(__dl_iterate_hdr_callback, void *) __exported; 255 int _rtld_addr_phdr(const void *, struct dl_phdr_info *) __exported; 256 int _rtld_get_stack_prot(void) __exported; 257 int _rtld_is_dlopened(void *) __exported; 258 void _rtld_error(const char *, ...) __exported; 259 260 /* Only here to fix -Wmissing-prototypes warnings */ 261 int __getosreldate(void); 262 func_ptr_type _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp); 263 Elf_Addr _rtld_bind(Obj_Entry *obj, Elf_Size reloff); 264 265 int npagesizes; 266 static int osreldate; 267 size_t *pagesizes; 268 size_t page_size; 269 270 static int stack_prot = PROT_READ | PROT_WRITE | PROT_EXEC; 271 static int max_stack_flags; 272 273 /* 274 * Global declarations normally provided by crt1. The dynamic linker is 275 * not built with crt1, so we have to provide them ourselves. 276 */ 277 char *__progname; 278 char **environ; 279 280 /* 281 * Used to pass argc, argv to init functions. 282 */ 283 int main_argc; 284 char **main_argv; 285 286 /* 287 * Globals to control TLS allocation. 288 */ 289 size_t tls_last_offset; /* Static TLS offset of last module */ 290 size_t tls_last_size; /* Static TLS size of last module */ 291 size_t tls_static_space; /* Static TLS space allocated */ 292 static size_t tls_static_max_align; 293 Elf_Addr tls_dtv_generation = 1; /* Used to detect when dtv size changes */ 294 int tls_max_index = 1; /* Largest module index allocated */ 295 296 static bool ld_library_path_rpath = false; 297 bool ld_fast_sigblock = false; 298 299 /* 300 * Globals for path names, and such 301 */ 302 const char *ld_elf_hints_default = _PATH_ELF_HINTS; 303 const char *ld_path_libmap_conf = _PATH_LIBMAP_CONF; 304 const char *ld_path_rtld = _PATH_RTLD; 305 const char *ld_standard_library_path = STANDARD_LIBRARY_PATH; 306 const char *ld_env_prefix = LD_; 307 308 static void (*rtld_exit_ptr)(void); 309 310 /* 311 * Fill in a DoneList with an allocation large enough to hold all of 312 * the currently-loaded objects. Keep this as a macro since it calls 313 * alloca and we want that to occur within the scope of the caller. 314 */ 315 #define donelist_init(dlp) \ 316 ((dlp)->objs = alloca(obj_count * sizeof (dlp)->objs[0]), \ 317 assert((dlp)->objs != NULL), \ 318 (dlp)->num_alloc = obj_count, \ 319 (dlp)->num_used = 0) 320 321 #define LD_UTRACE(e, h, mb, ms, r, n) do { \ 322 if (ld_utrace != NULL) \ 323 ld_utrace_log(e, h, mb, ms, r, n); \ 324 } while (0) 325 326 static void 327 ld_utrace_log(int event, void *handle, void *mapbase, size_t mapsize, 328 int refcnt, const char *name) 329 { 330 struct utrace_rtld ut; 331 static const char rtld_utrace_sig[RTLD_UTRACE_SIG_SZ] = RTLD_UTRACE_SIG; 332 333 memcpy(ut.sig, rtld_utrace_sig, sizeof(ut.sig)); 334 ut.event = event; 335 ut.handle = handle; 336 ut.mapbase = mapbase; 337 ut.mapsize = mapsize; 338 ut.refcnt = refcnt; 339 bzero(ut.name, sizeof(ut.name)); 340 if (name) 341 strlcpy(ut.name, name, sizeof(ut.name)); 342 utrace(&ut, sizeof(ut)); 343 } 344 345 enum { 346 LD_BIND_NOW = 0, 347 LD_PRELOAD, 348 LD_LIBMAP, 349 LD_LIBRARY_PATH, 350 LD_LIBRARY_PATH_FDS, 351 LD_LIBMAP_DISABLE, 352 LD_BIND_NOT, 353 LD_DEBUG, 354 LD_ELF_HINTS_PATH, 355 LD_LOADFLTR, 356 LD_LIBRARY_PATH_RPATH, 357 LD_PRELOAD_FDS, 358 LD_DYNAMIC_WEAK, 359 LD_TRACE_LOADED_OBJECTS, 360 LD_UTRACE, 361 LD_DUMP_REL_PRE, 362 LD_DUMP_REL_POST, 363 LD_TRACE_LOADED_OBJECTS_PROGNAME, 364 LD_TRACE_LOADED_OBJECTS_FMT1, 365 LD_TRACE_LOADED_OBJECTS_FMT2, 366 LD_TRACE_LOADED_OBJECTS_ALL, 367 LD_SHOW_AUXV, 368 }; 369 370 struct ld_env_var_desc { 371 const char * const n; 372 const char *val; 373 const bool unsecure; 374 }; 375 #define LD_ENV_DESC(var, unsec) \ 376 [LD_##var] = { .n = #var, .unsecure = unsec } 377 378 static struct ld_env_var_desc ld_env_vars[] = { 379 LD_ENV_DESC(BIND_NOW, false), 380 LD_ENV_DESC(PRELOAD, true), 381 LD_ENV_DESC(LIBMAP, true), 382 LD_ENV_DESC(LIBRARY_PATH, true), 383 LD_ENV_DESC(LIBRARY_PATH_FDS, true), 384 LD_ENV_DESC(LIBMAP_DISABLE, true), 385 LD_ENV_DESC(BIND_NOT, true), 386 LD_ENV_DESC(DEBUG, true), 387 LD_ENV_DESC(ELF_HINTS_PATH, true), 388 LD_ENV_DESC(LOADFLTR, true), 389 LD_ENV_DESC(LIBRARY_PATH_RPATH, true), 390 LD_ENV_DESC(PRELOAD_FDS, true), 391 LD_ENV_DESC(DYNAMIC_WEAK, true), 392 LD_ENV_DESC(TRACE_LOADED_OBJECTS, false), 393 LD_ENV_DESC(UTRACE, false), 394 LD_ENV_DESC(DUMP_REL_PRE, false), 395 LD_ENV_DESC(DUMP_REL_POST, false), 396 LD_ENV_DESC(TRACE_LOADED_OBJECTS_PROGNAME, false), 397 LD_ENV_DESC(TRACE_LOADED_OBJECTS_FMT1, false), 398 LD_ENV_DESC(TRACE_LOADED_OBJECTS_FMT2, false), 399 LD_ENV_DESC(TRACE_LOADED_OBJECTS_ALL, false), 400 LD_ENV_DESC(SHOW_AUXV, false), 401 }; 402 403 static const char * 404 ld_get_env_var(int idx) 405 { 406 return (ld_env_vars[idx].val); 407 } 408 409 static const char * 410 rtld_get_env_val(char **env, const char *name, size_t name_len) 411 { 412 char **m, *n, *v; 413 414 for (m = env; *m != NULL; m++) { 415 n = *m; 416 v = strchr(n, '='); 417 if (v == NULL) { 418 /* corrupt environment? */ 419 continue; 420 } 421 if (v - n == (ptrdiff_t)name_len && 422 strncmp(name, n, name_len) == 0) 423 return (v + 1); 424 } 425 return (NULL); 426 } 427 428 static void 429 rtld_init_env_vars_for_prefix(char **env, const char *env_prefix) 430 { 431 struct ld_env_var_desc *lvd; 432 size_t prefix_len, nlen; 433 char **m, *n, *v; 434 int i; 435 436 prefix_len = strlen(env_prefix); 437 for (m = env; *m != NULL; m++) { 438 n = *m; 439 if (strncmp(env_prefix, n, prefix_len) != 0) { 440 /* Not a rtld environment variable. */ 441 continue; 442 } 443 n += prefix_len; 444 v = strchr(n, '='); 445 if (v == NULL) { 446 /* corrupt environment? */ 447 continue; 448 } 449 for (i = 0; i < (int)nitems(ld_env_vars); i++) { 450 lvd = &ld_env_vars[i]; 451 if (lvd->val != NULL) { 452 /* Saw higher-priority variable name already. */ 453 continue; 454 } 455 nlen = strlen(lvd->n); 456 if (v - n == (ptrdiff_t)nlen && 457 strncmp(lvd->n, n, nlen) == 0) { 458 lvd->val = v + 1; 459 break; 460 } 461 } 462 } 463 } 464 465 static void 466 rtld_init_env_vars(char **env) 467 { 468 rtld_init_env_vars_for_prefix(env, ld_env_prefix); 469 } 470 471 static void 472 set_ld_elf_hints_path(void) 473 { 474 if (ld_elf_hints_path == NULL || strlen(ld_elf_hints_path) == 0) 475 ld_elf_hints_path = ld_elf_hints_default; 476 } 477 478 uintptr_t 479 rtld_round_page(uintptr_t x) 480 { 481 return (roundup2(x, page_size)); 482 } 483 484 uintptr_t 485 rtld_trunc_page(uintptr_t x) 486 { 487 return (rounddown2(x, page_size)); 488 } 489 490 /* 491 * Main entry point for dynamic linking. The first argument is the 492 * stack pointer. The stack is expected to be laid out as described 493 * in the SVR4 ABI specification, Intel 386 Processor Supplement. 494 * Specifically, the stack pointer points to a word containing 495 * ARGC. Following that in the stack is a null-terminated sequence 496 * of pointers to argument strings. Then comes a null-terminated 497 * sequence of pointers to environment strings. Finally, there is a 498 * sequence of "auxiliary vector" entries. 499 * 500 * The second argument points to a place to store the dynamic linker's 501 * exit procedure pointer and the third to a place to store the main 502 * program's object. 503 * 504 * The return value is the main program's entry point. 505 */ 506 func_ptr_type 507 _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp) 508 { 509 Elf_Auxinfo *aux, *auxp, *auxpf, *aux_info[AT_COUNT]; 510 Objlist_Entry *entry; 511 Obj_Entry *last_interposer, *obj, *preload_tail; 512 const Elf_Phdr *phdr; 513 Objlist initlist; 514 RtldLockState lockstate; 515 struct stat st; 516 Elf_Addr *argcp; 517 char **argv, **env, **envp, *kexecpath; 518 const char *argv0, *binpath, *library_path_rpath; 519 struct ld_env_var_desc *lvd; 520 caddr_t imgentry; 521 char buf[MAXPATHLEN]; 522 int argc, fd, i, mib[4], old_osrel, osrel, phnum, rtld_argc; 523 size_t sz; 524 #ifdef __powerpc__ 525 int old_auxv_format = 1; 526 #endif 527 bool dir_enable, dir_ignore, direct_exec, explicit_fd, search_in_path; 528 529 /* 530 * On entry, the dynamic linker itself has not been relocated yet. 531 * Be very careful not to reference any global data until after 532 * init_rtld has returned. It is OK to reference file-scope statics 533 * and string constants, and to call static and global functions. 534 */ 535 536 /* Find the auxiliary vector on the stack. */ 537 argcp = sp; 538 argc = *sp++; 539 argv = (char **) sp; 540 sp += argc + 1; /* Skip over arguments and NULL terminator */ 541 env = (char **) sp; 542 while (*sp++ != 0) /* Skip over environment, and NULL terminator */ 543 ; 544 aux = (Elf_Auxinfo *) sp; 545 546 /* Digest the auxiliary vector. */ 547 for (i = 0; i < AT_COUNT; i++) 548 aux_info[i] = NULL; 549 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) { 550 if (auxp->a_type < AT_COUNT) 551 aux_info[auxp->a_type] = auxp; 552 #ifdef __powerpc__ 553 if (auxp->a_type == 23) /* AT_STACKPROT */ 554 old_auxv_format = 0; 555 #endif 556 } 557 558 #ifdef __powerpc__ 559 if (old_auxv_format) { 560 /* Remap from old-style auxv numbers. */ 561 aux_info[23] = aux_info[21]; /* AT_STACKPROT */ 562 aux_info[21] = aux_info[19]; /* AT_PAGESIZESLEN */ 563 aux_info[19] = aux_info[17]; /* AT_NCPUS */ 564 aux_info[17] = aux_info[15]; /* AT_CANARYLEN */ 565 aux_info[15] = aux_info[13]; /* AT_EXECPATH */ 566 aux_info[13] = NULL; /* AT_GID */ 567 568 aux_info[20] = aux_info[18]; /* AT_PAGESIZES */ 569 aux_info[18] = aux_info[16]; /* AT_OSRELDATE */ 570 aux_info[16] = aux_info[14]; /* AT_CANARY */ 571 aux_info[14] = NULL; /* AT_EGID */ 572 } 573 #endif 574 575 /* Initialize and relocate ourselves. */ 576 assert(aux_info[AT_BASE] != NULL); 577 init_rtld((caddr_t) aux_info[AT_BASE]->a_un.a_ptr, aux_info); 578 579 dlerror_dflt_init(); 580 581 __progname = obj_rtld.path; 582 argv0 = argv[0] != NULL ? argv[0] : "(null)"; 583 environ = env; 584 main_argc = argc; 585 main_argv = argv; 586 587 if (aux_info[AT_BSDFLAGS] != NULL && 588 (aux_info[AT_BSDFLAGS]->a_un.a_val & ELF_BSDF_SIGFASTBLK) != 0) 589 ld_fast_sigblock = true; 590 591 trust = !issetugid(); 592 direct_exec = false; 593 594 md_abi_variant_hook(aux_info); 595 rtld_init_env_vars(env); 596 597 fd = -1; 598 if (aux_info[AT_EXECFD] != NULL) { 599 fd = aux_info[AT_EXECFD]->a_un.a_val; 600 } else { 601 assert(aux_info[AT_PHDR] != NULL); 602 phdr = (const Elf_Phdr *)aux_info[AT_PHDR]->a_un.a_ptr; 603 if (phdr == obj_rtld.phdr) { 604 if (!trust) { 605 _rtld_error("Tainted process refusing to run binary %s", 606 argv0); 607 rtld_die(); 608 } 609 direct_exec = true; 610 611 dbg("opening main program in direct exec mode"); 612 if (argc >= 2) { 613 rtld_argc = parse_args(argv, argc, &search_in_path, &fd, 614 &argv0, &dir_ignore); 615 explicit_fd = (fd != -1); 616 binpath = NULL; 617 if (!explicit_fd) 618 fd = open_binary_fd(argv0, search_in_path, &binpath); 619 if (fstat(fd, &st) == -1) { 620 _rtld_error("Failed to fstat FD %d (%s): %s", fd, 621 explicit_fd ? "user-provided descriptor" : argv0, 622 rtld_strerror(errno)); 623 rtld_die(); 624 } 625 626 /* 627 * Rough emulation of the permission checks done by 628 * execve(2), only Unix DACs are checked, ACLs are 629 * ignored. Preserve the semantic of disabling owner 630 * to execute if owner x bit is cleared, even if 631 * others x bit is enabled. 632 * mmap(2) does not allow to mmap with PROT_EXEC if 633 * binary' file comes from noexec mount. We cannot 634 * set a text reference on the binary. 635 */ 636 dir_enable = false; 637 if (st.st_uid == geteuid()) { 638 if ((st.st_mode & S_IXUSR) != 0) 639 dir_enable = true; 640 } else if (st.st_gid == getegid()) { 641 if ((st.st_mode & S_IXGRP) != 0) 642 dir_enable = true; 643 } else if ((st.st_mode & S_IXOTH) != 0) { 644 dir_enable = true; 645 } 646 if (!dir_enable && !dir_ignore) { 647 _rtld_error("No execute permission for binary %s", 648 argv0); 649 rtld_die(); 650 } 651 652 /* 653 * For direct exec mode, argv[0] is the interpreter 654 * name, we must remove it and shift arguments left 655 * before invoking binary main. Since stack layout 656 * places environment pointers and aux vectors right 657 * after the terminating NULL, we must shift 658 * environment and aux as well. 659 */ 660 main_argc = argc - rtld_argc; 661 for (i = 0; i <= main_argc; i++) 662 argv[i] = argv[i + rtld_argc]; 663 *argcp -= rtld_argc; 664 environ = env = envp = argv + main_argc + 1; 665 dbg("move env from %p to %p", envp + rtld_argc, envp); 666 do { 667 *envp = *(envp + rtld_argc); 668 } while (*envp++ != NULL); 669 aux = auxp = (Elf_Auxinfo *)envp; 670 auxpf = (Elf_Auxinfo *)(envp + rtld_argc); 671 dbg("move aux from %p to %p", auxpf, aux); 672 /* XXXKIB insert place for AT_EXECPATH if not present */ 673 for (;; auxp++, auxpf++) { 674 *auxp = *auxpf; 675 if (auxp->a_type == AT_NULL) 676 break; 677 } 678 /* Since the auxiliary vector has moved, redigest it. */ 679 for (i = 0; i < AT_COUNT; i++) 680 aux_info[i] = NULL; 681 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) { 682 if (auxp->a_type < AT_COUNT) 683 aux_info[auxp->a_type] = auxp; 684 } 685 686 /* Point AT_EXECPATH auxv and aux_info to the binary path. */ 687 if (binpath == NULL) { 688 aux_info[AT_EXECPATH] = NULL; 689 } else { 690 if (aux_info[AT_EXECPATH] == NULL) { 691 aux_info[AT_EXECPATH] = xmalloc(sizeof(Elf_Auxinfo)); 692 aux_info[AT_EXECPATH]->a_type = AT_EXECPATH; 693 } 694 aux_info[AT_EXECPATH]->a_un.a_ptr = __DECONST(void *, 695 binpath); 696 } 697 } else { 698 _rtld_error("No binary"); 699 rtld_die(); 700 } 701 } 702 } 703 704 ld_bind_now = ld_get_env_var(LD_BIND_NOW); 705 706 /* 707 * If the process is tainted, then we un-set the dangerous environment 708 * variables. The process will be marked as tainted until setuid(2) 709 * is called. If any child process calls setuid(2) we do not want any 710 * future processes to honor the potentially un-safe variables. 711 */ 712 if (!trust) { 713 for (i = 0; i < (int)nitems(ld_env_vars); i++) { 714 lvd = &ld_env_vars[i]; 715 if (lvd->unsecure) 716 lvd->val = NULL; 717 } 718 } 719 720 ld_debug = ld_get_env_var(LD_DEBUG); 721 if (ld_bind_now == NULL) 722 ld_bind_not = ld_get_env_var(LD_BIND_NOT) != NULL; 723 ld_dynamic_weak = ld_get_env_var(LD_DYNAMIC_WEAK) == NULL; 724 libmap_disable = ld_get_env_var(LD_LIBMAP_DISABLE) != NULL; 725 libmap_override = ld_get_env_var(LD_LIBMAP); 726 ld_library_path = ld_get_env_var(LD_LIBRARY_PATH); 727 ld_library_dirs = ld_get_env_var(LD_LIBRARY_PATH_FDS); 728 ld_preload = ld_get_env_var(LD_PRELOAD); 729 ld_preload_fds = ld_get_env_var(LD_PRELOAD_FDS); 730 ld_elf_hints_path = ld_get_env_var(LD_ELF_HINTS_PATH); 731 ld_loadfltr = ld_get_env_var(LD_LOADFLTR) != NULL; 732 library_path_rpath = ld_get_env_var(LD_LIBRARY_PATH_RPATH); 733 if (library_path_rpath != NULL) { 734 if (library_path_rpath[0] == 'y' || 735 library_path_rpath[0] == 'Y' || 736 library_path_rpath[0] == '1') 737 ld_library_path_rpath = true; 738 else 739 ld_library_path_rpath = false; 740 } 741 dangerous_ld_env = libmap_disable || libmap_override != NULL || 742 ld_library_path != NULL || ld_preload != NULL || 743 ld_elf_hints_path != NULL || ld_loadfltr || !ld_dynamic_weak; 744 ld_tracing = ld_get_env_var(LD_TRACE_LOADED_OBJECTS); 745 ld_utrace = ld_get_env_var(LD_UTRACE); 746 747 set_ld_elf_hints_path(); 748 if (ld_debug != NULL && *ld_debug != '\0') 749 debug = 1; 750 dbg("%s is initialized, base address = %p", __progname, 751 (caddr_t) aux_info[AT_BASE]->a_un.a_ptr); 752 dbg("RTLD dynamic = %p", obj_rtld.dynamic); 753 dbg("RTLD pltgot = %p", obj_rtld.pltgot); 754 755 dbg("initializing thread locks"); 756 lockdflt_init(); 757 758 /* 759 * Load the main program, or process its program header if it is 760 * already loaded. 761 */ 762 if (fd != -1) { /* Load the main program. */ 763 dbg("loading main program"); 764 obj_main = map_object(fd, argv0, NULL); 765 close(fd); 766 if (obj_main == NULL) 767 rtld_die(); 768 max_stack_flags = obj_main->stack_flags; 769 } else { /* Main program already loaded. */ 770 dbg("processing main program's program header"); 771 assert(aux_info[AT_PHDR] != NULL); 772 phdr = (const Elf_Phdr *) aux_info[AT_PHDR]->a_un.a_ptr; 773 assert(aux_info[AT_PHNUM] != NULL); 774 phnum = aux_info[AT_PHNUM]->a_un.a_val; 775 assert(aux_info[AT_PHENT] != NULL); 776 assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr)); 777 assert(aux_info[AT_ENTRY] != NULL); 778 imgentry = (caddr_t) aux_info[AT_ENTRY]->a_un.a_ptr; 779 if ((obj_main = digest_phdr(phdr, phnum, imgentry, argv0)) == NULL) 780 rtld_die(); 781 } 782 783 if (aux_info[AT_EXECPATH] != NULL && fd == -1) { 784 kexecpath = aux_info[AT_EXECPATH]->a_un.a_ptr; 785 dbg("AT_EXECPATH %p %s", kexecpath, kexecpath); 786 if (kexecpath[0] == '/') 787 obj_main->path = kexecpath; 788 else if (getcwd(buf, sizeof(buf)) == NULL || 789 strlcat(buf, "/", sizeof(buf)) >= sizeof(buf) || 790 strlcat(buf, kexecpath, sizeof(buf)) >= sizeof(buf)) 791 obj_main->path = xstrdup(argv0); 792 else 793 obj_main->path = xstrdup(buf); 794 } else { 795 dbg("No AT_EXECPATH or direct exec"); 796 obj_main->path = xstrdup(argv0); 797 } 798 dbg("obj_main path %s", obj_main->path); 799 obj_main->mainprog = true; 800 801 if (aux_info[AT_STACKPROT] != NULL && 802 aux_info[AT_STACKPROT]->a_un.a_val != 0) 803 stack_prot = aux_info[AT_STACKPROT]->a_un.a_val; 804 805 #ifndef COMPAT_libcompat 806 /* 807 * Get the actual dynamic linker pathname from the executable if 808 * possible. (It should always be possible.) That ensures that 809 * gdb will find the right dynamic linker even if a non-standard 810 * one is being used. 811 */ 812 if (obj_main->interp != NULL && 813 strcmp(obj_main->interp, obj_rtld.path) != 0) { 814 free(obj_rtld.path); 815 obj_rtld.path = xstrdup(obj_main->interp); 816 __progname = obj_rtld.path; 817 } 818 #endif 819 820 if (!digest_dynamic(obj_main, 0)) 821 rtld_die(); 822 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", 823 obj_main->path, obj_main->valid_hash_sysv, obj_main->valid_hash_gnu, 824 obj_main->dynsymcount); 825 826 linkmap_add(obj_main); 827 linkmap_add(&obj_rtld); 828 829 /* Link the main program into the list of objects. */ 830 TAILQ_INSERT_HEAD(&obj_list, obj_main, next); 831 obj_count++; 832 obj_loads++; 833 834 /* Initialize a fake symbol for resolving undefined weak references. */ 835 sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE); 836 sym_zero.st_shndx = SHN_UNDEF; 837 sym_zero.st_value = -(uintptr_t)obj_main->relocbase; 838 839 if (!libmap_disable) 840 libmap_disable = (bool)lm_init(libmap_override); 841 842 if (aux_info[AT_KPRELOAD] != NULL && 843 aux_info[AT_KPRELOAD]->a_un.a_ptr != NULL) { 844 dbg("loading kernel vdso"); 845 if (load_kpreload(aux_info[AT_KPRELOAD]->a_un.a_ptr) == -1) 846 rtld_die(); 847 } 848 849 dbg("loading LD_PRELOAD_FDS libraries"); 850 if (load_preload_objects(ld_preload_fds, true) == -1) 851 rtld_die(); 852 853 dbg("loading LD_PRELOAD libraries"); 854 if (load_preload_objects(ld_preload, false) == -1) 855 rtld_die(); 856 preload_tail = globallist_curr(TAILQ_LAST(&obj_list, obj_entry_q)); 857 858 dbg("loading needed objects"); 859 if (load_needed_objects(obj_main, ld_tracing != NULL ? RTLD_LO_TRACE : 860 0) == -1) 861 rtld_die(); 862 863 /* Make a list of all objects loaded at startup. */ 864 last_interposer = obj_main; 865 TAILQ_FOREACH(obj, &obj_list, next) { 866 if (obj->marker) 867 continue; 868 if (obj->z_interpose && obj != obj_main) { 869 objlist_put_after(&list_main, last_interposer, obj); 870 last_interposer = obj; 871 } else { 872 objlist_push_tail(&list_main, obj); 873 } 874 obj->refcount++; 875 } 876 877 dbg("checking for required versions"); 878 if (rtld_verify_versions(&list_main) == -1 && !ld_tracing) 879 rtld_die(); 880 881 if (ld_get_env_var(LD_SHOW_AUXV) != NULL) 882 dump_auxv(aux_info); 883 884 if (ld_tracing) { /* We're done */ 885 trace_loaded_objects(obj_main, true); 886 exit(0); 887 } 888 889 if (ld_get_env_var(LD_DUMP_REL_PRE) != NULL) { 890 dump_relocations(obj_main); 891 exit (0); 892 } 893 894 /* 895 * Processing tls relocations requires having the tls offsets 896 * initialized. Prepare offsets before starting initial 897 * relocation processing. 898 */ 899 dbg("initializing initial thread local storage offsets"); 900 STAILQ_FOREACH(entry, &list_main, link) { 901 /* 902 * Allocate all the initial objects out of the static TLS 903 * block even if they didn't ask for it. 904 */ 905 allocate_tls_offset(entry->obj); 906 } 907 908 if (relocate_objects(obj_main, 909 ld_bind_now != NULL && *ld_bind_now != '\0', 910 &obj_rtld, SYMLOOK_EARLY, NULL) == -1) 911 rtld_die(); 912 913 dbg("doing copy relocations"); 914 if (do_copy_relocations(obj_main) == -1) 915 rtld_die(); 916 917 if (ld_get_env_var(LD_DUMP_REL_POST) != NULL) { 918 dump_relocations(obj_main); 919 exit (0); 920 } 921 922 ifunc_init(aux); 923 924 /* 925 * Setup TLS for main thread. This must be done after the 926 * relocations are processed, since tls initialization section 927 * might be the subject for relocations. 928 */ 929 dbg("initializing initial thread local storage"); 930 allocate_initial_tls(globallist_curr(TAILQ_FIRST(&obj_list))); 931 932 dbg("initializing key program variables"); 933 set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : ""); 934 set_program_var("environ", env); 935 set_program_var("__elf_aux_vector", aux); 936 937 /* Make a list of init functions to call. */ 938 objlist_init(&initlist); 939 initlist_add_objects(globallist_curr(TAILQ_FIRST(&obj_list)), 940 preload_tail, &initlist); 941 942 r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */ 943 944 map_stacks_exec(NULL); 945 946 if (!obj_main->crt_no_init) { 947 /* 948 * Make sure we don't call the main program's init and fini 949 * functions for binaries linked with old crt1 which calls 950 * _init itself. 951 */ 952 obj_main->init = obj_main->fini = (Elf_Addr)NULL; 953 obj_main->preinit_array = obj_main->init_array = 954 obj_main->fini_array = (Elf_Addr)NULL; 955 } 956 957 if (direct_exec) { 958 /* Set osrel for direct-execed binary */ 959 mib[0] = CTL_KERN; 960 mib[1] = KERN_PROC; 961 mib[2] = KERN_PROC_OSREL; 962 mib[3] = getpid(); 963 osrel = obj_main->osrel; 964 sz = sizeof(old_osrel); 965 dbg("setting osrel to %d", osrel); 966 (void)sysctl(mib, 4, &old_osrel, &sz, &osrel, sizeof(osrel)); 967 } 968 969 wlock_acquire(rtld_bind_lock, &lockstate); 970 971 dbg("resolving ifuncs"); 972 if (initlist_objects_ifunc(&initlist, ld_bind_now != NULL && 973 *ld_bind_now != '\0', SYMLOOK_EARLY, &lockstate) == -1) 974 rtld_die(); 975 976 rtld_exit_ptr = rtld_exit; 977 if (obj_main->crt_no_init) 978 preinit_main(); 979 objlist_call_init(&initlist, &lockstate); 980 _r_debug_postinit(&obj_main->linkmap); 981 objlist_clear(&initlist); 982 dbg("loading filtees"); 983 TAILQ_FOREACH(obj, &obj_list, next) { 984 if (obj->marker) 985 continue; 986 if (ld_loadfltr || obj->z_loadfltr) 987 load_filtees(obj, 0, &lockstate); 988 } 989 990 dbg("enforcing main obj relro"); 991 if (obj_enforce_relro(obj_main) == -1) 992 rtld_die(); 993 994 lock_release(rtld_bind_lock, &lockstate); 995 996 dbg("transferring control to program entry point = %p", obj_main->entry); 997 998 /* Return the exit procedure and the program entry point. */ 999 *exit_proc = rtld_exit_ptr; 1000 *objp = obj_main; 1001 return ((func_ptr_type)obj_main->entry); 1002 } 1003 1004 void * 1005 rtld_resolve_ifunc(const Obj_Entry *obj, const Elf_Sym *def) 1006 { 1007 void *ptr; 1008 Elf_Addr target; 1009 1010 ptr = (void *)make_function_pointer(def, obj); 1011 target = call_ifunc_resolver(ptr); 1012 return ((void *)target); 1013 } 1014 1015 Elf_Addr 1016 _rtld_bind(Obj_Entry *obj, Elf_Size reloff) 1017 { 1018 const Elf_Rel *rel; 1019 const Elf_Sym *def; 1020 const Obj_Entry *defobj; 1021 Elf_Addr *where; 1022 Elf_Addr target; 1023 RtldLockState lockstate; 1024 1025 rlock_acquire(rtld_bind_lock, &lockstate); 1026 if (sigsetjmp(lockstate.env, 0) != 0) 1027 lock_upgrade(rtld_bind_lock, &lockstate); 1028 if (obj->pltrel) 1029 rel = (const Elf_Rel *)((const char *)obj->pltrel + reloff); 1030 else 1031 rel = (const Elf_Rel *)((const char *)obj->pltrela + reloff); 1032 1033 where = (Elf_Addr *)(obj->relocbase + rel->r_offset); 1034 def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, SYMLOOK_IN_PLT, 1035 NULL, &lockstate); 1036 if (def == NULL) 1037 rtld_die(); 1038 if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 1039 target = (Elf_Addr)rtld_resolve_ifunc(defobj, def); 1040 else 1041 target = (Elf_Addr)(defobj->relocbase + def->st_value); 1042 1043 dbg("\"%s\" in \"%s\" ==> %p in \"%s\"", 1044 defobj->strtab + def->st_name, 1045 obj->path == NULL ? NULL : basename(obj->path), 1046 (void *)target, 1047 defobj->path == NULL ? NULL : basename(defobj->path)); 1048 1049 /* 1050 * Write the new contents for the jmpslot. Note that depending on 1051 * architecture, the value which we need to return back to the 1052 * lazy binding trampoline may or may not be the target 1053 * address. The value returned from reloc_jmpslot() is the value 1054 * that the trampoline needs. 1055 */ 1056 target = reloc_jmpslot(where, target, defobj, obj, rel); 1057 lock_release(rtld_bind_lock, &lockstate); 1058 return (target); 1059 } 1060 1061 /* 1062 * Error reporting function. Use it like printf. If formats the message 1063 * into a buffer, and sets things up so that the next call to dlerror() 1064 * will return the message. 1065 */ 1066 void 1067 _rtld_error(const char *fmt, ...) 1068 { 1069 va_list ap; 1070 1071 va_start(ap, fmt); 1072 rtld_vsnprintf(lockinfo.dlerror_loc(), lockinfo.dlerror_loc_sz, 1073 fmt, ap); 1074 va_end(ap); 1075 *lockinfo.dlerror_seen() = 0; 1076 dbg("rtld_error: %s", lockinfo.dlerror_loc()); 1077 LD_UTRACE(UTRACE_RTLD_ERROR, NULL, NULL, 0, 0, lockinfo.dlerror_loc()); 1078 } 1079 1080 /* 1081 * Return a dynamically-allocated copy of the current error message, if any. 1082 */ 1083 static struct dlerror_save * 1084 errmsg_save(void) 1085 { 1086 struct dlerror_save *res; 1087 1088 res = xmalloc(sizeof(*res)); 1089 res->seen = *lockinfo.dlerror_seen(); 1090 if (res->seen == 0) 1091 res->msg = xstrdup(lockinfo.dlerror_loc()); 1092 return (res); 1093 } 1094 1095 /* 1096 * Restore the current error message from a copy which was previously saved 1097 * by errmsg_save(). The copy is freed. 1098 */ 1099 static void 1100 errmsg_restore(struct dlerror_save *saved_msg) 1101 { 1102 if (saved_msg == NULL || saved_msg->seen == 1) { 1103 *lockinfo.dlerror_seen() = 1; 1104 } else { 1105 *lockinfo.dlerror_seen() = 0; 1106 strlcpy(lockinfo.dlerror_loc(), saved_msg->msg, 1107 lockinfo.dlerror_loc_sz); 1108 free(saved_msg->msg); 1109 } 1110 free(saved_msg); 1111 } 1112 1113 static const char * 1114 basename(const char *name) 1115 { 1116 const char *p; 1117 1118 p = strrchr(name, '/'); 1119 return (p != NULL ? p + 1 : name); 1120 } 1121 1122 static struct utsname uts; 1123 1124 static char * 1125 origin_subst_one(Obj_Entry *obj, char *real, const char *kw, 1126 const char *subst, bool may_free) 1127 { 1128 char *p, *p1, *res, *resp; 1129 int subst_len, kw_len, subst_count, old_len, new_len; 1130 1131 kw_len = strlen(kw); 1132 1133 /* 1134 * First, count the number of the keyword occurrences, to 1135 * preallocate the final string. 1136 */ 1137 for (p = real, subst_count = 0;; p = p1 + kw_len, subst_count++) { 1138 p1 = strstr(p, kw); 1139 if (p1 == NULL) 1140 break; 1141 } 1142 1143 /* 1144 * If the keyword is not found, just return. 1145 * 1146 * Return non-substituted string if resolution failed. We 1147 * cannot do anything more reasonable, the failure mode of the 1148 * caller is unresolved library anyway. 1149 */ 1150 if (subst_count == 0 || (obj != NULL && !obj_resolve_origin(obj))) 1151 return (may_free ? real : xstrdup(real)); 1152 if (obj != NULL) 1153 subst = obj->origin_path; 1154 1155 /* 1156 * There is indeed something to substitute. Calculate the 1157 * length of the resulting string, and allocate it. 1158 */ 1159 subst_len = strlen(subst); 1160 old_len = strlen(real); 1161 new_len = old_len + (subst_len - kw_len) * subst_count; 1162 res = xmalloc(new_len + 1); 1163 1164 /* 1165 * Now, execute the substitution loop. 1166 */ 1167 for (p = real, resp = res, *resp = '\0';;) { 1168 p1 = strstr(p, kw); 1169 if (p1 != NULL) { 1170 /* Copy the prefix before keyword. */ 1171 memcpy(resp, p, p1 - p); 1172 resp += p1 - p; 1173 /* Keyword replacement. */ 1174 memcpy(resp, subst, subst_len); 1175 resp += subst_len; 1176 *resp = '\0'; 1177 p = p1 + kw_len; 1178 } else 1179 break; 1180 } 1181 1182 /* Copy to the end of string and finish. */ 1183 strcat(resp, p); 1184 if (may_free) 1185 free(real); 1186 return (res); 1187 } 1188 1189 static const struct { 1190 const char *kw; 1191 bool pass_obj; 1192 const char *subst; 1193 } tokens[] = { 1194 { .kw = "$ORIGIN", .pass_obj = true, .subst = NULL }, 1195 { .kw = "${ORIGIN}", .pass_obj = true, .subst = NULL }, 1196 { .kw = "$OSNAME", .pass_obj = false, .subst = uts.sysname }, 1197 { .kw = "${OSNAME}", .pass_obj = false, .subst = uts.sysname }, 1198 { .kw = "$OSREL", .pass_obj = false, .subst = uts.release }, 1199 { .kw = "${OSREL}", .pass_obj = false, .subst = uts.release }, 1200 { .kw = "$PLATFORM", .pass_obj = false, .subst = uts.machine }, 1201 { .kw = "${PLATFORM}", .pass_obj = false, .subst = uts.machine }, 1202 { .kw = "$LIB", .pass_obj = false, .subst = TOKEN_LIB }, 1203 { .kw = "${LIB}", .pass_obj = false, .subst = TOKEN_LIB }, 1204 }; 1205 1206 static char * 1207 origin_subst(Obj_Entry *obj, const char *real) 1208 { 1209 char *res; 1210 int i; 1211 1212 if (obj == NULL || !trust) 1213 return (xstrdup(real)); 1214 if (uts.sysname[0] == '\0') { 1215 if (uname(&uts) != 0) { 1216 _rtld_error("utsname failed: %d", errno); 1217 return (NULL); 1218 } 1219 } 1220 1221 /* __DECONST is safe here since without may_free real is unchanged */ 1222 res = __DECONST(char *, real); 1223 for (i = 0; i < (int)nitems(tokens); i++) { 1224 res = origin_subst_one(tokens[i].pass_obj ? obj : NULL, 1225 res, tokens[i].kw, tokens[i].subst, i != 0); 1226 } 1227 return (res); 1228 } 1229 1230 void 1231 rtld_die(void) 1232 { 1233 const char *msg = dlerror(); 1234 1235 if (msg == NULL) 1236 msg = "Fatal error"; 1237 rtld_fdputstr(STDERR_FILENO, _BASENAME_RTLD ": "); 1238 rtld_fdputstr(STDERR_FILENO, msg); 1239 rtld_fdputchar(STDERR_FILENO, '\n'); 1240 _exit(1); 1241 } 1242 1243 /* 1244 * Process a shared object's DYNAMIC section, and save the important 1245 * information in its Obj_Entry structure. 1246 */ 1247 static void 1248 digest_dynamic1(Obj_Entry *obj, int early, const Elf_Dyn **dyn_rpath, 1249 const Elf_Dyn **dyn_soname, const Elf_Dyn **dyn_runpath) 1250 { 1251 const Elf_Dyn *dynp; 1252 Needed_Entry **needed_tail = &obj->needed; 1253 Needed_Entry **needed_filtees_tail = &obj->needed_filtees; 1254 Needed_Entry **needed_aux_filtees_tail = &obj->needed_aux_filtees; 1255 const Elf_Hashelt *hashtab; 1256 const Elf32_Word *hashval; 1257 Elf32_Word bkt, nmaskwords; 1258 int bloom_size32; 1259 int plttype = DT_REL; 1260 1261 *dyn_rpath = NULL; 1262 *dyn_soname = NULL; 1263 *dyn_runpath = NULL; 1264 1265 obj->bind_now = false; 1266 dynp = obj->dynamic; 1267 if (dynp == NULL) 1268 return; 1269 for (; dynp->d_tag != DT_NULL; dynp++) { 1270 switch (dynp->d_tag) { 1271 1272 case DT_REL: 1273 obj->rel = (const Elf_Rel *)(obj->relocbase + dynp->d_un.d_ptr); 1274 break; 1275 1276 case DT_RELSZ: 1277 obj->relsize = dynp->d_un.d_val; 1278 break; 1279 1280 case DT_RELENT: 1281 assert(dynp->d_un.d_val == sizeof(Elf_Rel)); 1282 break; 1283 1284 case DT_JMPREL: 1285 obj->pltrel = (const Elf_Rel *) 1286 (obj->relocbase + dynp->d_un.d_ptr); 1287 break; 1288 1289 case DT_PLTRELSZ: 1290 obj->pltrelsize = dynp->d_un.d_val; 1291 break; 1292 1293 case DT_RELA: 1294 obj->rela = (const Elf_Rela *)(obj->relocbase + dynp->d_un.d_ptr); 1295 break; 1296 1297 case DT_RELASZ: 1298 obj->relasize = dynp->d_un.d_val; 1299 break; 1300 1301 case DT_RELAENT: 1302 assert(dynp->d_un.d_val == sizeof(Elf_Rela)); 1303 break; 1304 1305 case DT_RELR: 1306 obj->relr = (const Elf_Relr *)(obj->relocbase + dynp->d_un.d_ptr); 1307 break; 1308 1309 case DT_RELRSZ: 1310 obj->relrsize = dynp->d_un.d_val; 1311 break; 1312 1313 case DT_RELRENT: 1314 assert(dynp->d_un.d_val == sizeof(Elf_Relr)); 1315 break; 1316 1317 case DT_PLTREL: 1318 plttype = dynp->d_un.d_val; 1319 assert(dynp->d_un.d_val == DT_REL || plttype == DT_RELA); 1320 break; 1321 1322 case DT_SYMTAB: 1323 obj->symtab = (const Elf_Sym *) 1324 (obj->relocbase + dynp->d_un.d_ptr); 1325 break; 1326 1327 case DT_SYMENT: 1328 assert(dynp->d_un.d_val == sizeof(Elf_Sym)); 1329 break; 1330 1331 case DT_STRTAB: 1332 obj->strtab = (const char *)(obj->relocbase + dynp->d_un.d_ptr); 1333 break; 1334 1335 case DT_STRSZ: 1336 obj->strsize = dynp->d_un.d_val; 1337 break; 1338 1339 case DT_VERNEED: 1340 obj->verneed = (const Elf_Verneed *)(obj->relocbase + 1341 dynp->d_un.d_val); 1342 break; 1343 1344 case DT_VERNEEDNUM: 1345 obj->verneednum = dynp->d_un.d_val; 1346 break; 1347 1348 case DT_VERDEF: 1349 obj->verdef = (const Elf_Verdef *)(obj->relocbase + 1350 dynp->d_un.d_val); 1351 break; 1352 1353 case DT_VERDEFNUM: 1354 obj->verdefnum = dynp->d_un.d_val; 1355 break; 1356 1357 case DT_VERSYM: 1358 obj->versyms = (const Elf_Versym *)(obj->relocbase + 1359 dynp->d_un.d_val); 1360 break; 1361 1362 case DT_HASH: 1363 { 1364 hashtab = (const Elf_Hashelt *)(obj->relocbase + 1365 dynp->d_un.d_ptr); 1366 obj->nbuckets = hashtab[0]; 1367 obj->nchains = hashtab[1]; 1368 obj->buckets = hashtab + 2; 1369 obj->chains = obj->buckets + obj->nbuckets; 1370 obj->valid_hash_sysv = obj->nbuckets > 0 && obj->nchains > 0 && 1371 obj->buckets != NULL; 1372 } 1373 break; 1374 1375 case DT_GNU_HASH: 1376 { 1377 hashtab = (const Elf_Hashelt *)(obj->relocbase + 1378 dynp->d_un.d_ptr); 1379 obj->nbuckets_gnu = hashtab[0]; 1380 obj->symndx_gnu = hashtab[1]; 1381 nmaskwords = hashtab[2]; 1382 bloom_size32 = (__ELF_WORD_SIZE / 32) * nmaskwords; 1383 obj->maskwords_bm_gnu = nmaskwords - 1; 1384 obj->shift2_gnu = hashtab[3]; 1385 obj->bloom_gnu = (const Elf_Addr *)(hashtab + 4); 1386 obj->buckets_gnu = hashtab + 4 + bloom_size32; 1387 obj->chain_zero_gnu = obj->buckets_gnu + obj->nbuckets_gnu - 1388 obj->symndx_gnu; 1389 /* Number of bitmask words is required to be power of 2 */ 1390 obj->valid_hash_gnu = powerof2(nmaskwords) && 1391 obj->nbuckets_gnu > 0 && obj->buckets_gnu != NULL; 1392 } 1393 break; 1394 1395 case DT_NEEDED: 1396 if (!obj->rtld) { 1397 Needed_Entry *nep = NEW(Needed_Entry); 1398 nep->name = dynp->d_un.d_val; 1399 nep->obj = NULL; 1400 nep->next = NULL; 1401 1402 *needed_tail = nep; 1403 needed_tail = &nep->next; 1404 } 1405 break; 1406 1407 case DT_FILTER: 1408 if (!obj->rtld) { 1409 Needed_Entry *nep = NEW(Needed_Entry); 1410 nep->name = dynp->d_un.d_val; 1411 nep->obj = NULL; 1412 nep->next = NULL; 1413 1414 *needed_filtees_tail = nep; 1415 needed_filtees_tail = &nep->next; 1416 1417 if (obj->linkmap.l_refname == NULL) 1418 obj->linkmap.l_refname = (char *)dynp->d_un.d_val; 1419 } 1420 break; 1421 1422 case DT_AUXILIARY: 1423 if (!obj->rtld) { 1424 Needed_Entry *nep = NEW(Needed_Entry); 1425 nep->name = dynp->d_un.d_val; 1426 nep->obj = NULL; 1427 nep->next = NULL; 1428 1429 *needed_aux_filtees_tail = nep; 1430 needed_aux_filtees_tail = &nep->next; 1431 } 1432 break; 1433 1434 case DT_PLTGOT: 1435 obj->pltgot = (Elf_Addr *)(obj->relocbase + dynp->d_un.d_ptr); 1436 break; 1437 1438 case DT_TEXTREL: 1439 obj->textrel = true; 1440 break; 1441 1442 case DT_SYMBOLIC: 1443 obj->symbolic = true; 1444 break; 1445 1446 case DT_RPATH: 1447 /* 1448 * We have to wait until later to process this, because we 1449 * might not have gotten the address of the string table yet. 1450 */ 1451 *dyn_rpath = dynp; 1452 break; 1453 1454 case DT_SONAME: 1455 *dyn_soname = dynp; 1456 break; 1457 1458 case DT_RUNPATH: 1459 *dyn_runpath = dynp; 1460 break; 1461 1462 case DT_INIT: 1463 obj->init = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1464 break; 1465 1466 case DT_PREINIT_ARRAY: 1467 obj->preinit_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1468 break; 1469 1470 case DT_PREINIT_ARRAYSZ: 1471 obj->preinit_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1472 break; 1473 1474 case DT_INIT_ARRAY: 1475 obj->init_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1476 break; 1477 1478 case DT_INIT_ARRAYSZ: 1479 obj->init_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1480 break; 1481 1482 case DT_FINI: 1483 obj->fini = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1484 break; 1485 1486 case DT_FINI_ARRAY: 1487 obj->fini_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1488 break; 1489 1490 case DT_FINI_ARRAYSZ: 1491 obj->fini_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1492 break; 1493 1494 case DT_DEBUG: 1495 if (!early) 1496 dbg("Filling in DT_DEBUG entry"); 1497 (__DECONST(Elf_Dyn *, dynp))->d_un.d_ptr = (Elf_Addr)&r_debug; 1498 break; 1499 1500 case DT_FLAGS: 1501 if (dynp->d_un.d_val & DF_ORIGIN) 1502 obj->z_origin = true; 1503 if (dynp->d_un.d_val & DF_SYMBOLIC) 1504 obj->symbolic = true; 1505 if (dynp->d_un.d_val & DF_TEXTREL) 1506 obj->textrel = true; 1507 if (dynp->d_un.d_val & DF_BIND_NOW) 1508 obj->bind_now = true; 1509 if (dynp->d_un.d_val & DF_STATIC_TLS) 1510 obj->static_tls = true; 1511 break; 1512 1513 #ifdef __powerpc__ 1514 #ifdef __powerpc64__ 1515 case DT_PPC64_GLINK: 1516 obj->glink = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1517 break; 1518 #else 1519 case DT_PPC_GOT: 1520 obj->gotptr = (Elf_Addr *)(obj->relocbase + dynp->d_un.d_ptr); 1521 break; 1522 #endif 1523 #endif 1524 1525 case DT_FLAGS_1: 1526 if (dynp->d_un.d_val & DF_1_NOOPEN) 1527 obj->z_noopen = true; 1528 if (dynp->d_un.d_val & DF_1_ORIGIN) 1529 obj->z_origin = true; 1530 if (dynp->d_un.d_val & DF_1_GLOBAL) 1531 obj->z_global = true; 1532 if (dynp->d_un.d_val & DF_1_BIND_NOW) 1533 obj->bind_now = true; 1534 if (dynp->d_un.d_val & DF_1_NODELETE) 1535 obj->z_nodelete = true; 1536 if (dynp->d_un.d_val & DF_1_LOADFLTR) 1537 obj->z_loadfltr = true; 1538 if (dynp->d_un.d_val & DF_1_INTERPOSE) 1539 obj->z_interpose = true; 1540 if (dynp->d_un.d_val & DF_1_NODEFLIB) 1541 obj->z_nodeflib = true; 1542 if (dynp->d_un.d_val & DF_1_PIE) 1543 obj->z_pie = true; 1544 break; 1545 1546 default: 1547 if (!early) { 1548 dbg("Ignoring d_tag %ld = %#lx", (long)dynp->d_tag, 1549 (long)dynp->d_tag); 1550 } 1551 break; 1552 } 1553 } 1554 1555 obj->traced = false; 1556 1557 if (plttype == DT_RELA) { 1558 obj->pltrela = (const Elf_Rela *) obj->pltrel; 1559 obj->pltrel = NULL; 1560 obj->pltrelasize = obj->pltrelsize; 1561 obj->pltrelsize = 0; 1562 } 1563 1564 /* Determine size of dynsym table (equal to nchains of sysv hash) */ 1565 if (obj->valid_hash_sysv) 1566 obj->dynsymcount = obj->nchains; 1567 else if (obj->valid_hash_gnu) { 1568 obj->dynsymcount = 0; 1569 for (bkt = 0; bkt < obj->nbuckets_gnu; bkt++) { 1570 if (obj->buckets_gnu[bkt] == 0) 1571 continue; 1572 hashval = &obj->chain_zero_gnu[obj->buckets_gnu[bkt]]; 1573 do 1574 obj->dynsymcount++; 1575 while ((*hashval++ & 1u) == 0); 1576 } 1577 obj->dynsymcount += obj->symndx_gnu; 1578 } 1579 1580 if (obj->linkmap.l_refname != NULL) 1581 obj->linkmap.l_refname = obj->strtab + (unsigned long)obj-> 1582 linkmap.l_refname; 1583 } 1584 1585 static bool 1586 obj_resolve_origin(Obj_Entry *obj) 1587 { 1588 1589 if (obj->origin_path != NULL) 1590 return (true); 1591 obj->origin_path = xmalloc(PATH_MAX); 1592 return (rtld_dirname_abs(obj->path, obj->origin_path) != -1); 1593 } 1594 1595 static bool 1596 digest_dynamic2(Obj_Entry *obj, const Elf_Dyn *dyn_rpath, 1597 const Elf_Dyn *dyn_soname, const Elf_Dyn *dyn_runpath) 1598 { 1599 1600 if (obj->z_origin && !obj_resolve_origin(obj)) 1601 return (false); 1602 1603 if (dyn_runpath != NULL) { 1604 obj->runpath = (const char *)obj->strtab + dyn_runpath->d_un.d_val; 1605 obj->runpath = origin_subst(obj, obj->runpath); 1606 } else if (dyn_rpath != NULL) { 1607 obj->rpath = (const char *)obj->strtab + dyn_rpath->d_un.d_val; 1608 obj->rpath = origin_subst(obj, obj->rpath); 1609 } 1610 if (dyn_soname != NULL) 1611 object_add_name(obj, obj->strtab + dyn_soname->d_un.d_val); 1612 return (true); 1613 } 1614 1615 static bool 1616 digest_dynamic(Obj_Entry *obj, int early) 1617 { 1618 const Elf_Dyn *dyn_rpath; 1619 const Elf_Dyn *dyn_soname; 1620 const Elf_Dyn *dyn_runpath; 1621 1622 digest_dynamic1(obj, early, &dyn_rpath, &dyn_soname, &dyn_runpath); 1623 return (digest_dynamic2(obj, dyn_rpath, dyn_soname, dyn_runpath)); 1624 } 1625 1626 /* 1627 * Process a shared object's program header. This is used only for the 1628 * main program, when the kernel has already loaded the main program 1629 * into memory before calling the dynamic linker. It creates and 1630 * returns an Obj_Entry structure. 1631 */ 1632 static Obj_Entry * 1633 digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path) 1634 { 1635 Obj_Entry *obj; 1636 const Elf_Phdr *phlimit = phdr + phnum; 1637 const Elf_Phdr *ph; 1638 Elf_Addr note_start, note_end; 1639 int nsegs = 0; 1640 1641 obj = obj_new(); 1642 for (ph = phdr; ph < phlimit; ph++) { 1643 if (ph->p_type != PT_PHDR) 1644 continue; 1645 1646 obj->phdr = phdr; 1647 obj->phsize = ph->p_memsz; 1648 obj->relocbase = __DECONST(char *, phdr) - ph->p_vaddr; 1649 break; 1650 } 1651 1652 obj->stack_flags = PF_X | PF_R | PF_W; 1653 1654 for (ph = phdr; ph < phlimit; ph++) { 1655 switch (ph->p_type) { 1656 1657 case PT_INTERP: 1658 obj->interp = (const char *)(ph->p_vaddr + obj->relocbase); 1659 break; 1660 1661 case PT_LOAD: 1662 if (nsegs == 0) { /* First load segment */ 1663 obj->vaddrbase = rtld_trunc_page(ph->p_vaddr); 1664 obj->mapbase = obj->vaddrbase + obj->relocbase; 1665 } else { /* Last load segment */ 1666 obj->mapsize = rtld_round_page(ph->p_vaddr + ph->p_memsz) - 1667 obj->vaddrbase; 1668 } 1669 nsegs++; 1670 break; 1671 1672 case PT_DYNAMIC: 1673 obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + obj->relocbase); 1674 break; 1675 1676 case PT_TLS: 1677 obj->tlsindex = 1; 1678 obj->tlssize = ph->p_memsz; 1679 obj->tlsalign = ph->p_align; 1680 obj->tlsinitsize = ph->p_filesz; 1681 obj->tlsinit = (void*)(ph->p_vaddr + obj->relocbase); 1682 obj->tlspoffset = ph->p_offset; 1683 break; 1684 1685 case PT_GNU_STACK: 1686 obj->stack_flags = ph->p_flags; 1687 break; 1688 1689 case PT_GNU_RELRO: 1690 obj->relro_page = obj->relocbase + rtld_trunc_page(ph->p_vaddr); 1691 obj->relro_size = rtld_trunc_page(ph->p_vaddr + ph->p_memsz) - 1692 rtld_trunc_page(ph->p_vaddr); 1693 break; 1694 1695 case PT_NOTE: 1696 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; 1697 note_end = note_start + ph->p_filesz; 1698 digest_notes(obj, note_start, note_end); 1699 break; 1700 } 1701 } 1702 if (nsegs < 1) { 1703 _rtld_error("%s: too few PT_LOAD segments", path); 1704 return (NULL); 1705 } 1706 1707 obj->entry = entry; 1708 return (obj); 1709 } 1710 1711 void 1712 digest_notes(Obj_Entry *obj, Elf_Addr note_start, Elf_Addr note_end) 1713 { 1714 const Elf_Note *note; 1715 const char *note_name; 1716 uintptr_t p; 1717 1718 for (note = (const Elf_Note *)note_start; (Elf_Addr)note < note_end; 1719 note = (const Elf_Note *)((const char *)(note + 1) + 1720 roundup2(note->n_namesz, sizeof(Elf32_Addr)) + 1721 roundup2(note->n_descsz, sizeof(Elf32_Addr)))) { 1722 if (note->n_namesz != sizeof(NOTE_FREEBSD_VENDOR) || 1723 note->n_descsz != sizeof(int32_t)) 1724 continue; 1725 if (note->n_type != NT_FREEBSD_ABI_TAG && 1726 note->n_type != NT_FREEBSD_FEATURE_CTL && 1727 note->n_type != NT_FREEBSD_NOINIT_TAG) 1728 continue; 1729 note_name = (const char *)(note + 1); 1730 if (strncmp(NOTE_FREEBSD_VENDOR, note_name, 1731 sizeof(NOTE_FREEBSD_VENDOR)) != 0) 1732 continue; 1733 switch (note->n_type) { 1734 case NT_FREEBSD_ABI_TAG: 1735 /* FreeBSD osrel note */ 1736 p = (uintptr_t)(note + 1); 1737 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1738 obj->osrel = *(const int32_t *)(p); 1739 dbg("note osrel %d", obj->osrel); 1740 break; 1741 case NT_FREEBSD_FEATURE_CTL: 1742 /* FreeBSD ABI feature control note */ 1743 p = (uintptr_t)(note + 1); 1744 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1745 obj->fctl0 = *(const uint32_t *)(p); 1746 dbg("note fctl0 %#x", obj->fctl0); 1747 break; 1748 case NT_FREEBSD_NOINIT_TAG: 1749 /* FreeBSD 'crt does not call init' note */ 1750 obj->crt_no_init = true; 1751 dbg("note crt_no_init"); 1752 break; 1753 } 1754 } 1755 } 1756 1757 static Obj_Entry * 1758 dlcheck(void *handle) 1759 { 1760 Obj_Entry *obj; 1761 1762 TAILQ_FOREACH(obj, &obj_list, next) { 1763 if (obj == (Obj_Entry *) handle) 1764 break; 1765 } 1766 1767 if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) { 1768 _rtld_error("Invalid shared object handle %p", handle); 1769 return (NULL); 1770 } 1771 return (obj); 1772 } 1773 1774 /* 1775 * If the given object is already in the donelist, return true. Otherwise 1776 * add the object to the list and return false. 1777 */ 1778 static bool 1779 donelist_check(DoneList *dlp, const Obj_Entry *obj) 1780 { 1781 unsigned int i; 1782 1783 for (i = 0; i < dlp->num_used; i++) 1784 if (dlp->objs[i] == obj) 1785 return (true); 1786 /* 1787 * Our donelist allocation should always be sufficient. But if 1788 * our threads locking isn't working properly, more shared objects 1789 * could have been loaded since we allocated the list. That should 1790 * never happen, but we'll handle it properly just in case it does. 1791 */ 1792 if (dlp->num_used < dlp->num_alloc) 1793 dlp->objs[dlp->num_used++] = obj; 1794 return (false); 1795 } 1796 1797 /* 1798 * SysV hash function for symbol table lookup. It is a slightly optimized 1799 * version of the hash specified by the System V ABI. 1800 */ 1801 Elf32_Word 1802 elf_hash(const char *name) 1803 { 1804 const unsigned char *p = (const unsigned char *)name; 1805 Elf32_Word h = 0; 1806 1807 while (*p != '\0') { 1808 h = (h << 4) + *p++; 1809 h ^= (h >> 24) & 0xf0; 1810 } 1811 return (h & 0x0fffffff); 1812 } 1813 1814 /* 1815 * The GNU hash function is the Daniel J. Bernstein hash clipped to 32 bits 1816 * unsigned in case it's implemented with a wider type. 1817 */ 1818 static uint32_t 1819 gnu_hash(const char *s) 1820 { 1821 uint32_t h; 1822 unsigned char c; 1823 1824 h = 5381; 1825 for (c = *s; c != '\0'; c = *++s) 1826 h = h * 33 + c; 1827 return (h & 0xffffffff); 1828 } 1829 1830 1831 /* 1832 * Find the library with the given name, and return its full pathname. 1833 * The returned string is dynamically allocated. Generates an error 1834 * message and returns NULL if the library cannot be found. 1835 * 1836 * If the second argument is non-NULL, then it refers to an already- 1837 * loaded shared object, whose library search path will be searched. 1838 * 1839 * If a library is successfully located via LD_LIBRARY_PATH_FDS, its 1840 * descriptor (which is close-on-exec) will be passed out via the third 1841 * argument. 1842 * 1843 * The search order is: 1844 * DT_RPATH in the referencing file _unless_ DT_RUNPATH is present (1) 1845 * DT_RPATH of the main object if DSO without defined DT_RUNPATH (1) 1846 * LD_LIBRARY_PATH 1847 * DT_RUNPATH in the referencing file 1848 * ldconfig hints (if -z nodefaultlib, filter out default library directories 1849 * from list) 1850 * /lib:/usr/lib _unless_ the referencing file is linked with -z nodefaultlib 1851 * 1852 * (1) Handled in digest_dynamic2 - rpath left NULL if runpath defined. 1853 */ 1854 static char * 1855 find_library(const char *xname, const Obj_Entry *refobj, int *fdp) 1856 { 1857 char *pathname, *refobj_path; 1858 const char *name; 1859 bool nodeflib, objgiven; 1860 1861 objgiven = refobj != NULL; 1862 1863 if (libmap_disable || !objgiven || 1864 (name = lm_find(refobj->path, xname)) == NULL) 1865 name = xname; 1866 1867 if (strchr(name, '/') != NULL) { /* Hard coded pathname */ 1868 if (name[0] != '/' && !trust) { 1869 _rtld_error("Absolute pathname required " 1870 "for shared object \"%s\"", name); 1871 return (NULL); 1872 } 1873 return (origin_subst(__DECONST(Obj_Entry *, refobj), 1874 __DECONST(char *, name))); 1875 } 1876 1877 dbg(" Searching for \"%s\"", name); 1878 refobj_path = objgiven ? refobj->path : NULL; 1879 1880 /* 1881 * If refobj->rpath != NULL, then refobj->runpath is NULL. Fall 1882 * back to pre-conforming behaviour if user requested so with 1883 * LD_LIBRARY_PATH_RPATH environment variable and ignore -z 1884 * nodeflib. 1885 */ 1886 if (objgiven && refobj->rpath != NULL && ld_library_path_rpath) { 1887 pathname = search_library_path(name, ld_library_path, 1888 refobj_path, fdp); 1889 if (pathname != NULL) 1890 return (pathname); 1891 if (refobj != NULL) { 1892 pathname = search_library_path(name, refobj->rpath, 1893 refobj_path, fdp); 1894 if (pathname != NULL) 1895 return (pathname); 1896 } 1897 pathname = search_library_pathfds(name, ld_library_dirs, fdp); 1898 if (pathname != NULL) 1899 return (pathname); 1900 pathname = search_library_path(name, gethints(false), 1901 refobj_path, fdp); 1902 if (pathname != NULL) 1903 return (pathname); 1904 pathname = search_library_path(name, ld_standard_library_path, 1905 refobj_path, fdp); 1906 if (pathname != NULL) 1907 return (pathname); 1908 } else { 1909 nodeflib = objgiven ? refobj->z_nodeflib : false; 1910 if (objgiven) { 1911 pathname = search_library_path(name, refobj->rpath, 1912 refobj->path, fdp); 1913 if (pathname != NULL) 1914 return (pathname); 1915 } 1916 if (objgiven && refobj->runpath == NULL && refobj != obj_main) { 1917 pathname = search_library_path(name, obj_main->rpath, 1918 refobj_path, fdp); 1919 if (pathname != NULL) 1920 return (pathname); 1921 } 1922 pathname = search_library_path(name, ld_library_path, 1923 refobj_path, fdp); 1924 if (pathname != NULL) 1925 return (pathname); 1926 if (objgiven) { 1927 pathname = search_library_path(name, refobj->runpath, 1928 refobj_path, fdp); 1929 if (pathname != NULL) 1930 return (pathname); 1931 } 1932 pathname = search_library_pathfds(name, ld_library_dirs, fdp); 1933 if (pathname != NULL) 1934 return (pathname); 1935 pathname = search_library_path(name, gethints(nodeflib), 1936 refobj_path, fdp); 1937 if (pathname != NULL) 1938 return (pathname); 1939 if (objgiven && !nodeflib) { 1940 pathname = search_library_path(name, 1941 ld_standard_library_path, refobj_path, fdp); 1942 if (pathname != NULL) 1943 return (pathname); 1944 } 1945 } 1946 1947 if (objgiven && refobj->path != NULL) { 1948 _rtld_error("Shared object \"%s\" not found, " 1949 "required by \"%s\"", name, basename(refobj->path)); 1950 } else { 1951 _rtld_error("Shared object \"%s\" not found", name); 1952 } 1953 return (NULL); 1954 } 1955 1956 /* 1957 * Given a symbol number in a referencing object, find the corresponding 1958 * definition of the symbol. Returns a pointer to the symbol, or NULL if 1959 * no definition was found. Returns a pointer to the Obj_Entry of the 1960 * defining object via the reference parameter DEFOBJ_OUT. 1961 */ 1962 const Elf_Sym * 1963 find_symdef(unsigned long symnum, const Obj_Entry *refobj, 1964 const Obj_Entry **defobj_out, int flags, SymCache *cache, 1965 RtldLockState *lockstate) 1966 { 1967 const Elf_Sym *ref; 1968 const Elf_Sym *def; 1969 const Obj_Entry *defobj; 1970 const Ver_Entry *ve; 1971 SymLook req; 1972 const char *name; 1973 int res; 1974 1975 /* 1976 * If we have already found this symbol, get the information from 1977 * the cache. 1978 */ 1979 if (symnum >= refobj->dynsymcount) 1980 return (NULL); /* Bad object */ 1981 if (cache != NULL && cache[symnum].sym != NULL) { 1982 *defobj_out = cache[symnum].obj; 1983 return (cache[symnum].sym); 1984 } 1985 1986 ref = refobj->symtab + symnum; 1987 name = refobj->strtab + ref->st_name; 1988 def = NULL; 1989 defobj = NULL; 1990 ve = NULL; 1991 1992 /* 1993 * We don't have to do a full scale lookup if the symbol is local. 1994 * We know it will bind to the instance in this load module; to 1995 * which we already have a pointer (ie ref). By not doing a lookup, 1996 * we not only improve performance, but it also avoids unresolvable 1997 * symbols when local symbols are not in the hash table. This has 1998 * been seen with the ia64 toolchain. 1999 */ 2000 if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) { 2001 if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) { 2002 _rtld_error("%s: Bogus symbol table entry %lu", refobj->path, 2003 symnum); 2004 } 2005 symlook_init(&req, name); 2006 req.flags = flags; 2007 ve = req.ventry = fetch_ventry(refobj, symnum); 2008 req.lockstate = lockstate; 2009 res = symlook_default(&req, refobj); 2010 if (res == 0) { 2011 def = req.sym_out; 2012 defobj = req.defobj_out; 2013 } 2014 } else { 2015 def = ref; 2016 defobj = refobj; 2017 } 2018 2019 /* 2020 * If we found no definition and the reference is weak, treat the 2021 * symbol as having the value zero. 2022 */ 2023 if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) { 2024 def = &sym_zero; 2025 defobj = obj_main; 2026 } 2027 2028 if (def != NULL) { 2029 *defobj_out = defobj; 2030 /* Record the information in the cache to avoid subsequent lookups. */ 2031 if (cache != NULL) { 2032 cache[symnum].sym = def; 2033 cache[symnum].obj = defobj; 2034 } 2035 } else { 2036 if (refobj != &obj_rtld) 2037 _rtld_error("%s: Undefined symbol \"%s%s%s\"", refobj->path, name, 2038 ve != NULL ? "@" : "", ve != NULL ? ve->name : ""); 2039 } 2040 return (def); 2041 } 2042 2043 /* 2044 * Return the search path from the ldconfig hints file, reading it if 2045 * necessary. If nostdlib is true, then the default search paths are 2046 * not added to result. 2047 * 2048 * Returns NULL if there are problems with the hints file, 2049 * or if the search path there is empty. 2050 */ 2051 static const char * 2052 gethints(bool nostdlib) 2053 { 2054 static char *filtered_path; 2055 static const char *hints; 2056 static struct elfhints_hdr hdr; 2057 struct fill_search_info_args sargs, hargs; 2058 struct dl_serinfo smeta, hmeta, *SLPinfo, *hintinfo; 2059 struct dl_serpath *SLPpath, *hintpath; 2060 char *p; 2061 struct stat hint_stat; 2062 unsigned int SLPndx, hintndx, fndx, fcount; 2063 int fd; 2064 size_t flen; 2065 uint32_t dl; 2066 bool skip; 2067 2068 /* First call, read the hints file */ 2069 if (hints == NULL) { 2070 /* Keep from trying again in case the hints file is bad. */ 2071 hints = ""; 2072 2073 if ((fd = open(ld_elf_hints_path, O_RDONLY | O_CLOEXEC)) == -1) 2074 return (NULL); 2075 2076 /* 2077 * Check of hdr.dirlistlen value against type limit 2078 * intends to pacify static analyzers. Further 2079 * paranoia leads to checks that dirlist is fully 2080 * contained in the file range. 2081 */ 2082 if (read(fd, &hdr, sizeof hdr) != sizeof hdr || 2083 hdr.magic != ELFHINTS_MAGIC || 2084 hdr.version != 1 || hdr.dirlistlen > UINT_MAX / 2 || 2085 fstat(fd, &hint_stat) == -1) { 2086 cleanup1: 2087 close(fd); 2088 hdr.dirlistlen = 0; 2089 return (NULL); 2090 } 2091 dl = hdr.strtab; 2092 if (dl + hdr.dirlist < dl) 2093 goto cleanup1; 2094 dl += hdr.dirlist; 2095 if (dl + hdr.dirlistlen < dl) 2096 goto cleanup1; 2097 dl += hdr.dirlistlen; 2098 if (dl > hint_stat.st_size) 2099 goto cleanup1; 2100 p = xmalloc(hdr.dirlistlen + 1); 2101 if (pread(fd, p, hdr.dirlistlen + 1, 2102 hdr.strtab + hdr.dirlist) != (ssize_t)hdr.dirlistlen + 1 || 2103 p[hdr.dirlistlen] != '\0') { 2104 free(p); 2105 goto cleanup1; 2106 } 2107 hints = p; 2108 close(fd); 2109 } 2110 2111 /* 2112 * If caller agreed to receive list which includes the default 2113 * paths, we are done. Otherwise, if we still did not 2114 * calculated filtered result, do it now. 2115 */ 2116 if (!nostdlib) 2117 return (hints[0] != '\0' ? hints : NULL); 2118 if (filtered_path != NULL) 2119 goto filt_ret; 2120 2121 /* 2122 * Obtain the list of all configured search paths, and the 2123 * list of the default paths. 2124 * 2125 * First estimate the size of the results. 2126 */ 2127 smeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 2128 smeta.dls_cnt = 0; 2129 hmeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 2130 hmeta.dls_cnt = 0; 2131 2132 sargs.request = RTLD_DI_SERINFOSIZE; 2133 sargs.serinfo = &smeta; 2134 hargs.request = RTLD_DI_SERINFOSIZE; 2135 hargs.serinfo = &hmeta; 2136 2137 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 2138 &sargs); 2139 path_enumerate(hints, fill_search_info, NULL, &hargs); 2140 2141 SLPinfo = xmalloc(smeta.dls_size); 2142 hintinfo = xmalloc(hmeta.dls_size); 2143 2144 /* 2145 * Next fetch both sets of paths. 2146 */ 2147 sargs.request = RTLD_DI_SERINFO; 2148 sargs.serinfo = SLPinfo; 2149 sargs.serpath = &SLPinfo->dls_serpath[0]; 2150 sargs.strspace = (char *)&SLPinfo->dls_serpath[smeta.dls_cnt]; 2151 2152 hargs.request = RTLD_DI_SERINFO; 2153 hargs.serinfo = hintinfo; 2154 hargs.serpath = &hintinfo->dls_serpath[0]; 2155 hargs.strspace = (char *)&hintinfo->dls_serpath[hmeta.dls_cnt]; 2156 2157 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 2158 &sargs); 2159 path_enumerate(hints, fill_search_info, NULL, &hargs); 2160 2161 /* 2162 * Now calculate the difference between two sets, by excluding 2163 * standard paths from the full set. 2164 */ 2165 fndx = 0; 2166 fcount = 0; 2167 filtered_path = xmalloc(hdr.dirlistlen + 1); 2168 hintpath = &hintinfo->dls_serpath[0]; 2169 for (hintndx = 0; hintndx < hmeta.dls_cnt; hintndx++, hintpath++) { 2170 skip = false; 2171 SLPpath = &SLPinfo->dls_serpath[0]; 2172 /* 2173 * Check each standard path against current. 2174 */ 2175 for (SLPndx = 0; SLPndx < smeta.dls_cnt; SLPndx++, SLPpath++) { 2176 /* matched, skip the path */ 2177 if (!strcmp(hintpath->dls_name, SLPpath->dls_name)) { 2178 skip = true; 2179 break; 2180 } 2181 } 2182 if (skip) 2183 continue; 2184 /* 2185 * Not matched against any standard path, add the path 2186 * to result. Separate consequtive paths with ':'. 2187 */ 2188 if (fcount > 0) { 2189 filtered_path[fndx] = ':'; 2190 fndx++; 2191 } 2192 fcount++; 2193 flen = strlen(hintpath->dls_name); 2194 strncpy((filtered_path + fndx), hintpath->dls_name, flen); 2195 fndx += flen; 2196 } 2197 filtered_path[fndx] = '\0'; 2198 2199 free(SLPinfo); 2200 free(hintinfo); 2201 2202 filt_ret: 2203 return (filtered_path[0] != '\0' ? filtered_path : NULL); 2204 } 2205 2206 static void 2207 init_dag(Obj_Entry *root) 2208 { 2209 const Needed_Entry *needed; 2210 const Objlist_Entry *elm; 2211 DoneList donelist; 2212 2213 if (root->dag_inited) 2214 return; 2215 donelist_init(&donelist); 2216 2217 /* Root object belongs to own DAG. */ 2218 objlist_push_tail(&root->dldags, root); 2219 objlist_push_tail(&root->dagmembers, root); 2220 donelist_check(&donelist, root); 2221 2222 /* 2223 * Add dependencies of root object to DAG in breadth order 2224 * by exploiting the fact that each new object get added 2225 * to the tail of the dagmembers list. 2226 */ 2227 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2228 for (needed = elm->obj->needed; needed != NULL; needed = needed->next) { 2229 if (needed->obj == NULL || donelist_check(&donelist, needed->obj)) 2230 continue; 2231 objlist_push_tail(&needed->obj->dldags, root); 2232 objlist_push_tail(&root->dagmembers, needed->obj); 2233 } 2234 } 2235 root->dag_inited = true; 2236 } 2237 2238 static void 2239 init_marker(Obj_Entry *marker) 2240 { 2241 2242 bzero(marker, sizeof(*marker)); 2243 marker->marker = true; 2244 } 2245 2246 Obj_Entry * 2247 globallist_curr(const Obj_Entry *obj) 2248 { 2249 2250 for (;;) { 2251 if (obj == NULL) 2252 return (NULL); 2253 if (!obj->marker) 2254 return (__DECONST(Obj_Entry *, obj)); 2255 obj = TAILQ_PREV(obj, obj_entry_q, next); 2256 } 2257 } 2258 2259 Obj_Entry * 2260 globallist_next(const Obj_Entry *obj) 2261 { 2262 2263 for (;;) { 2264 obj = TAILQ_NEXT(obj, next); 2265 if (obj == NULL) 2266 return (NULL); 2267 if (!obj->marker) 2268 return (__DECONST(Obj_Entry *, obj)); 2269 } 2270 } 2271 2272 /* Prevent the object from being unmapped while the bind lock is dropped. */ 2273 static void 2274 hold_object(Obj_Entry *obj) 2275 { 2276 2277 obj->holdcount++; 2278 } 2279 2280 static void 2281 unhold_object(Obj_Entry *obj) 2282 { 2283 2284 assert(obj->holdcount > 0); 2285 if (--obj->holdcount == 0 && obj->unholdfree) 2286 release_object(obj); 2287 } 2288 2289 static void 2290 process_z(Obj_Entry *root) 2291 { 2292 const Objlist_Entry *elm; 2293 Obj_Entry *obj; 2294 2295 /* 2296 * Walk over object DAG and process every dependent object 2297 * that is marked as DF_1_NODELETE or DF_1_GLOBAL. They need 2298 * to grow their own DAG. 2299 * 2300 * For DF_1_GLOBAL, DAG is required for symbol lookups in 2301 * symlook_global() to work. 2302 * 2303 * For DF_1_NODELETE, the DAG should have its reference upped. 2304 */ 2305 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2306 obj = elm->obj; 2307 if (obj == NULL) 2308 continue; 2309 if (obj->z_nodelete && !obj->ref_nodel) { 2310 dbg("obj %s -z nodelete", obj->path); 2311 init_dag(obj); 2312 ref_dag(obj); 2313 obj->ref_nodel = true; 2314 } 2315 if (obj->z_global && objlist_find(&list_global, obj) == NULL) { 2316 dbg("obj %s -z global", obj->path); 2317 objlist_push_tail(&list_global, obj); 2318 init_dag(obj); 2319 } 2320 } 2321 } 2322 2323 static void 2324 parse_rtld_phdr(Obj_Entry *obj) 2325 { 2326 const Elf_Phdr *ph; 2327 Elf_Addr note_start, note_end; 2328 2329 obj->stack_flags = PF_X | PF_R | PF_W; 2330 for (ph = obj->phdr; (const char *)ph < (const char *)obj->phdr + 2331 obj->phsize; ph++) { 2332 switch (ph->p_type) { 2333 case PT_GNU_STACK: 2334 obj->stack_flags = ph->p_flags; 2335 break; 2336 case PT_GNU_RELRO: 2337 obj->relro_page = obj->relocbase + 2338 rtld_trunc_page(ph->p_vaddr); 2339 obj->relro_size = rtld_round_page(ph->p_memsz); 2340 break; 2341 case PT_NOTE: 2342 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; 2343 note_end = note_start + ph->p_filesz; 2344 digest_notes(obj, note_start, note_end); 2345 break; 2346 } 2347 } 2348 } 2349 2350 /* 2351 * Initialize the dynamic linker. The argument is the address at which 2352 * the dynamic linker has been mapped into memory. The primary task of 2353 * this function is to relocate the dynamic linker. 2354 */ 2355 static void 2356 init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info) 2357 { 2358 Obj_Entry objtmp; /* Temporary rtld object */ 2359 const Elf_Ehdr *ehdr; 2360 const Elf_Dyn *dyn_rpath; 2361 const Elf_Dyn *dyn_soname; 2362 const Elf_Dyn *dyn_runpath; 2363 2364 #ifdef RTLD_INIT_PAGESIZES_EARLY 2365 /* The page size is required by the dynamic memory allocator. */ 2366 init_pagesizes(aux_info); 2367 #endif 2368 2369 /* 2370 * Conjure up an Obj_Entry structure for the dynamic linker. 2371 * 2372 * The "path" member can't be initialized yet because string constants 2373 * cannot yet be accessed. Below we will set it correctly. 2374 */ 2375 memset(&objtmp, 0, sizeof(objtmp)); 2376 objtmp.path = NULL; 2377 objtmp.rtld = true; 2378 objtmp.mapbase = mapbase; 2379 #ifdef PIC 2380 objtmp.relocbase = mapbase; 2381 #endif 2382 2383 objtmp.dynamic = rtld_dynamic(&objtmp); 2384 digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname, &dyn_runpath); 2385 assert(objtmp.needed == NULL); 2386 assert(!objtmp.textrel); 2387 /* 2388 * Temporarily put the dynamic linker entry into the object list, so 2389 * that symbols can be found. 2390 */ 2391 relocate_objects(&objtmp, true, &objtmp, 0, NULL); 2392 2393 ehdr = (Elf_Ehdr *)mapbase; 2394 objtmp.phdr = (Elf_Phdr *)((char *)mapbase + ehdr->e_phoff); 2395 objtmp.phsize = ehdr->e_phnum * sizeof(objtmp.phdr[0]); 2396 2397 /* Initialize the object list. */ 2398 TAILQ_INIT(&obj_list); 2399 2400 /* Now that non-local variables can be accesses, copy out obj_rtld. */ 2401 memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld)); 2402 2403 #ifndef RTLD_INIT_PAGESIZES_EARLY 2404 /* The page size is required by the dynamic memory allocator. */ 2405 init_pagesizes(aux_info); 2406 #endif 2407 2408 if (aux_info[AT_OSRELDATE] != NULL) 2409 osreldate = aux_info[AT_OSRELDATE]->a_un.a_val; 2410 2411 digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname, dyn_runpath); 2412 2413 /* Replace the path with a dynamically allocated copy. */ 2414 obj_rtld.path = xstrdup(ld_path_rtld); 2415 2416 parse_rtld_phdr(&obj_rtld); 2417 if (obj_enforce_relro(&obj_rtld) == -1) 2418 rtld_die(); 2419 2420 r_debug.r_version = R_DEBUG_VERSION; 2421 r_debug.r_brk = r_debug_state; 2422 r_debug.r_state = RT_CONSISTENT; 2423 r_debug.r_ldbase = obj_rtld.relocbase; 2424 } 2425 2426 /* 2427 * Retrieve the array of supported page sizes. The kernel provides the page 2428 * sizes in increasing order. 2429 */ 2430 static void 2431 init_pagesizes(Elf_Auxinfo **aux_info) 2432 { 2433 static size_t psa[MAXPAGESIZES]; 2434 int mib[2]; 2435 size_t len, size; 2436 2437 if (aux_info[AT_PAGESIZES] != NULL && aux_info[AT_PAGESIZESLEN] != 2438 NULL) { 2439 size = aux_info[AT_PAGESIZESLEN]->a_un.a_val; 2440 pagesizes = aux_info[AT_PAGESIZES]->a_un.a_ptr; 2441 } else { 2442 len = 2; 2443 if (sysctlnametomib("hw.pagesizes", mib, &len) == 0) 2444 size = sizeof(psa); 2445 else { 2446 /* As a fallback, retrieve the base page size. */ 2447 size = sizeof(psa[0]); 2448 if (aux_info[AT_PAGESZ] != NULL) { 2449 psa[0] = aux_info[AT_PAGESZ]->a_un.a_val; 2450 goto psa_filled; 2451 } else { 2452 mib[0] = CTL_HW; 2453 mib[1] = HW_PAGESIZE; 2454 len = 2; 2455 } 2456 } 2457 if (sysctl(mib, len, psa, &size, NULL, 0) == -1) { 2458 _rtld_error("sysctl for hw.pagesize(s) failed"); 2459 rtld_die(); 2460 } 2461 psa_filled: 2462 pagesizes = psa; 2463 } 2464 npagesizes = size / sizeof(pagesizes[0]); 2465 /* Discard any invalid entries at the end of the array. */ 2466 while (npagesizes > 0 && pagesizes[npagesizes - 1] == 0) 2467 npagesizes--; 2468 2469 page_size = pagesizes[0]; 2470 } 2471 2472 /* 2473 * Add the init functions from a needed object list (and its recursive 2474 * needed objects) to "list". This is not used directly; it is a helper 2475 * function for initlist_add_objects(). The write lock must be held 2476 * when this function is called. 2477 */ 2478 static void 2479 initlist_add_neededs(Needed_Entry *needed, Objlist *list) 2480 { 2481 /* Recursively process the successor needed objects. */ 2482 if (needed->next != NULL) 2483 initlist_add_neededs(needed->next, list); 2484 2485 /* Process the current needed object. */ 2486 if (needed->obj != NULL) 2487 initlist_add_objects(needed->obj, needed->obj, list); 2488 } 2489 2490 /* 2491 * Scan all of the DAGs rooted in the range of objects from "obj" to 2492 * "tail" and add their init functions to "list". This recurses over 2493 * the DAGs and ensure the proper init ordering such that each object's 2494 * needed libraries are initialized before the object itself. At the 2495 * same time, this function adds the objects to the global finalization 2496 * list "list_fini" in the opposite order. The write lock must be 2497 * held when this function is called. 2498 */ 2499 static void 2500 initlist_add_objects(Obj_Entry *obj, Obj_Entry *tail, Objlist *list) 2501 { 2502 Obj_Entry *nobj; 2503 2504 if (obj->init_scanned || obj->init_done) 2505 return; 2506 obj->init_scanned = true; 2507 2508 /* Recursively process the successor objects. */ 2509 nobj = globallist_next(obj); 2510 if (nobj != NULL && obj != tail) 2511 initlist_add_objects(nobj, tail, list); 2512 2513 /* Recursively process the needed objects. */ 2514 if (obj->needed != NULL) 2515 initlist_add_neededs(obj->needed, list); 2516 if (obj->needed_filtees != NULL) 2517 initlist_add_neededs(obj->needed_filtees, list); 2518 if (obj->needed_aux_filtees != NULL) 2519 initlist_add_neededs(obj->needed_aux_filtees, list); 2520 2521 /* Add the object to the init list. */ 2522 objlist_push_tail(list, obj); 2523 2524 /* Add the object to the global fini list in the reverse order. */ 2525 if ((obj->fini != (Elf_Addr)NULL || obj->fini_array != (Elf_Addr)NULL) 2526 && !obj->on_fini_list) { 2527 objlist_push_head(&list_fini, obj); 2528 obj->on_fini_list = true; 2529 } 2530 } 2531 2532 static void 2533 free_needed_filtees(Needed_Entry *n, RtldLockState *lockstate) 2534 { 2535 Needed_Entry *needed, *needed1; 2536 2537 for (needed = n; needed != NULL; needed = needed->next) { 2538 if (needed->obj != NULL) { 2539 dlclose_locked(needed->obj, lockstate); 2540 needed->obj = NULL; 2541 } 2542 } 2543 for (needed = n; needed != NULL; needed = needed1) { 2544 needed1 = needed->next; 2545 free(needed); 2546 } 2547 } 2548 2549 static void 2550 unload_filtees(Obj_Entry *obj, RtldLockState *lockstate) 2551 { 2552 2553 free_needed_filtees(obj->needed_filtees, lockstate); 2554 obj->needed_filtees = NULL; 2555 free_needed_filtees(obj->needed_aux_filtees, lockstate); 2556 obj->needed_aux_filtees = NULL; 2557 obj->filtees_loaded = false; 2558 } 2559 2560 static void 2561 load_filtee1(Obj_Entry *obj, Needed_Entry *needed, int flags, 2562 RtldLockState *lockstate) 2563 { 2564 2565 for (; needed != NULL; needed = needed->next) { 2566 needed->obj = dlopen_object(obj->strtab + needed->name, -1, obj, 2567 flags, ((ld_loadfltr || obj->z_loadfltr) ? RTLD_NOW : RTLD_LAZY) | 2568 RTLD_LOCAL, lockstate); 2569 } 2570 } 2571 2572 static void 2573 load_filtees(Obj_Entry *obj, int flags, RtldLockState *lockstate) 2574 { 2575 if (obj->filtees_loaded || obj->filtees_loading) 2576 return; 2577 lock_restart_for_upgrade(lockstate); 2578 obj->filtees_loading = true; 2579 load_filtee1(obj, obj->needed_filtees, flags, lockstate); 2580 load_filtee1(obj, obj->needed_aux_filtees, flags, lockstate); 2581 obj->filtees_loaded = true; 2582 obj->filtees_loading = false; 2583 } 2584 2585 static int 2586 process_needed(Obj_Entry *obj, Needed_Entry *needed, int flags) 2587 { 2588 Obj_Entry *obj1; 2589 2590 for (; needed != NULL; needed = needed->next) { 2591 obj1 = needed->obj = load_object(obj->strtab + needed->name, -1, obj, 2592 flags & ~RTLD_LO_NOLOAD); 2593 if (obj1 == NULL && !ld_tracing && (flags & RTLD_LO_FILTEES) == 0) 2594 return (-1); 2595 } 2596 return (0); 2597 } 2598 2599 /* 2600 * Given a shared object, traverse its list of needed objects, and load 2601 * each of them. Returns 0 on success. Generates an error message and 2602 * returns -1 on failure. 2603 */ 2604 static int 2605 load_needed_objects(Obj_Entry *first, int flags) 2606 { 2607 Obj_Entry *obj; 2608 2609 for (obj = first; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 2610 if (obj->marker) 2611 continue; 2612 if (process_needed(obj, obj->needed, flags) == -1) 2613 return (-1); 2614 } 2615 return (0); 2616 } 2617 2618 static int 2619 load_preload_objects(const char *penv, bool isfd) 2620 { 2621 Obj_Entry *obj; 2622 const char *name; 2623 size_t len; 2624 char savech, *p, *psave; 2625 int fd; 2626 static const char delim[] = " \t:;"; 2627 2628 if (penv == NULL) 2629 return (0); 2630 2631 p = psave = xstrdup(penv); 2632 p += strspn(p, delim); 2633 while (*p != '\0') { 2634 len = strcspn(p, delim); 2635 2636 savech = p[len]; 2637 p[len] = '\0'; 2638 if (isfd) { 2639 name = NULL; 2640 fd = parse_integer(p); 2641 if (fd == -1) { 2642 free(psave); 2643 return (-1); 2644 } 2645 } else { 2646 name = p; 2647 fd = -1; 2648 } 2649 2650 obj = load_object(name, fd, NULL, 0); 2651 if (obj == NULL) { 2652 free(psave); 2653 return (-1); /* XXX - cleanup */ 2654 } 2655 obj->z_interpose = true; 2656 p[len] = savech; 2657 p += len; 2658 p += strspn(p, delim); 2659 } 2660 LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL); 2661 2662 free(psave); 2663 return (0); 2664 } 2665 2666 static const char * 2667 printable_path(const char *path) 2668 { 2669 2670 return (path == NULL ? "<unknown>" : path); 2671 } 2672 2673 /* 2674 * Load a shared object into memory, if it is not already loaded. The 2675 * object may be specified by name or by user-supplied file descriptor 2676 * fd_u. In the later case, the fd_u descriptor is not closed, but its 2677 * duplicate is. 2678 * 2679 * Returns a pointer to the Obj_Entry for the object. Returns NULL 2680 * on failure. 2681 */ 2682 static Obj_Entry * 2683 load_object(const char *name, int fd_u, const Obj_Entry *refobj, int flags) 2684 { 2685 Obj_Entry *obj; 2686 int fd; 2687 struct stat sb; 2688 char *path; 2689 2690 fd = -1; 2691 if (name != NULL) { 2692 TAILQ_FOREACH(obj, &obj_list, next) { 2693 if (obj->marker || obj->doomed) 2694 continue; 2695 if (object_match_name(obj, name)) 2696 return (obj); 2697 } 2698 2699 path = find_library(name, refobj, &fd); 2700 if (path == NULL) 2701 return (NULL); 2702 } else 2703 path = NULL; 2704 2705 if (fd >= 0) { 2706 /* 2707 * search_library_pathfds() opens a fresh file descriptor for the 2708 * library, so there is no need to dup(). 2709 */ 2710 } else if (fd_u == -1) { 2711 /* 2712 * If we didn't find a match by pathname, or the name is not 2713 * supplied, open the file and check again by device and inode. 2714 * This avoids false mismatches caused by multiple links or ".." 2715 * in pathnames. 2716 * 2717 * To avoid a race, we open the file and use fstat() rather than 2718 * using stat(). 2719 */ 2720 if ((fd = open(path, O_RDONLY | O_CLOEXEC | O_VERIFY)) == -1) { 2721 _rtld_error("Cannot open \"%s\"", path); 2722 free(path); 2723 return (NULL); 2724 } 2725 } else { 2726 fd = fcntl(fd_u, F_DUPFD_CLOEXEC, 0); 2727 if (fd == -1) { 2728 _rtld_error("Cannot dup fd"); 2729 free(path); 2730 return (NULL); 2731 } 2732 } 2733 if (fstat(fd, &sb) == -1) { 2734 _rtld_error("Cannot fstat \"%s\"", printable_path(path)); 2735 close(fd); 2736 free(path); 2737 return (NULL); 2738 } 2739 TAILQ_FOREACH(obj, &obj_list, next) { 2740 if (obj->marker || obj->doomed) 2741 continue; 2742 if (obj->ino == sb.st_ino && obj->dev == sb.st_dev) 2743 break; 2744 } 2745 if (obj != NULL) { 2746 if (name != NULL) 2747 object_add_name(obj, name); 2748 free(path); 2749 close(fd); 2750 return (obj); 2751 } 2752 if (flags & RTLD_LO_NOLOAD) { 2753 free(path); 2754 close(fd); 2755 return (NULL); 2756 } 2757 2758 /* First use of this object, so we must map it in */ 2759 obj = do_load_object(fd, name, path, &sb, flags); 2760 if (obj == NULL) 2761 free(path); 2762 close(fd); 2763 2764 return (obj); 2765 } 2766 2767 static Obj_Entry * 2768 do_load_object(int fd, const char *name, char *path, struct stat *sbp, 2769 int flags) 2770 { 2771 Obj_Entry *obj; 2772 struct statfs fs; 2773 2774 /* 2775 * First, make sure that environment variables haven't been 2776 * used to circumvent the noexec flag on a filesystem. 2777 * We ignore fstatfs(2) failures, since fd might reference 2778 * not a file, e.g. shmfd. 2779 */ 2780 if (dangerous_ld_env && fstatfs(fd, &fs) == 0 && 2781 (fs.f_flags & MNT_NOEXEC) != 0) { 2782 _rtld_error("Cannot execute objects on %s", fs.f_mntonname); 2783 return (NULL); 2784 } 2785 2786 dbg("loading \"%s\"", printable_path(path)); 2787 obj = map_object(fd, printable_path(path), sbp); 2788 if (obj == NULL) 2789 return (NULL); 2790 2791 /* 2792 * If DT_SONAME is present in the object, digest_dynamic2 already 2793 * added it to the object names. 2794 */ 2795 if (name != NULL) 2796 object_add_name(obj, name); 2797 obj->path = path; 2798 if (!digest_dynamic(obj, 0)) 2799 goto errp; 2800 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", obj->path, 2801 obj->valid_hash_sysv, obj->valid_hash_gnu, obj->dynsymcount); 2802 if (obj->z_pie && (flags & RTLD_LO_TRACE) == 0) { 2803 dbg("refusing to load PIE executable \"%s\"", obj->path); 2804 _rtld_error("Cannot load PIE binary %s as DSO", obj->path); 2805 goto errp; 2806 } 2807 if (obj->z_noopen && (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) == 2808 RTLD_LO_DLOPEN) { 2809 dbg("refusing to load non-loadable \"%s\"", obj->path); 2810 _rtld_error("Cannot dlopen non-loadable %s", obj->path); 2811 goto errp; 2812 } 2813 2814 obj->dlopened = (flags & RTLD_LO_DLOPEN) != 0; 2815 TAILQ_INSERT_TAIL(&obj_list, obj, next); 2816 obj_count++; 2817 obj_loads++; 2818 linkmap_add(obj); /* for GDB & dlinfo() */ 2819 max_stack_flags |= obj->stack_flags; 2820 2821 dbg(" %p .. %p: %s", obj->mapbase, 2822 obj->mapbase + obj->mapsize - 1, obj->path); 2823 if (obj->textrel) 2824 dbg(" WARNING: %s has impure text", obj->path); 2825 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 2826 obj->path); 2827 2828 return (obj); 2829 2830 errp: 2831 munmap(obj->mapbase, obj->mapsize); 2832 obj_free(obj); 2833 return (NULL); 2834 } 2835 2836 static int 2837 load_kpreload(const void *addr) 2838 { 2839 Obj_Entry *obj; 2840 const Elf_Ehdr *ehdr; 2841 const Elf_Phdr *phdr, *phlimit, *phdyn, *seg0, *segn; 2842 static const char kname[] = "[vdso]"; 2843 2844 ehdr = addr; 2845 if (!check_elf_headers(ehdr, "kpreload")) 2846 return (-1); 2847 obj = obj_new(); 2848 phdr = (const Elf_Phdr *)((const char *)addr + ehdr->e_phoff); 2849 obj->phdr = phdr; 2850 obj->phsize = ehdr->e_phnum * sizeof(*phdr); 2851 phlimit = phdr + ehdr->e_phnum; 2852 seg0 = segn = NULL; 2853 2854 for (; phdr < phlimit; phdr++) { 2855 switch (phdr->p_type) { 2856 case PT_DYNAMIC: 2857 phdyn = phdr; 2858 break; 2859 case PT_GNU_STACK: 2860 /* Absense of PT_GNU_STACK implies stack_flags == 0. */ 2861 obj->stack_flags = phdr->p_flags; 2862 break; 2863 case PT_LOAD: 2864 if (seg0 == NULL || seg0->p_vaddr > phdr->p_vaddr) 2865 seg0 = phdr; 2866 if (segn == NULL || segn->p_vaddr + segn->p_memsz < 2867 phdr->p_vaddr + phdr->p_memsz) 2868 segn = phdr; 2869 break; 2870 } 2871 } 2872 2873 obj->mapbase = __DECONST(caddr_t, addr); 2874 obj->mapsize = segn->p_vaddr + segn->p_memsz - (Elf_Addr)addr; 2875 obj->vaddrbase = 0; 2876 obj->relocbase = obj->mapbase; 2877 2878 object_add_name(obj, kname); 2879 obj->path = xstrdup(kname); 2880 obj->dynamic = (const Elf_Dyn *)(obj->relocbase + phdyn->p_vaddr); 2881 2882 if (!digest_dynamic(obj, 0)) { 2883 obj_free(obj); 2884 return (-1); 2885 } 2886 2887 /* 2888 * We assume that kernel-preloaded object does not need 2889 * relocation. It is currently written into read-only page, 2890 * handling relocations would mean we need to allocate at 2891 * least one additional page per AS. 2892 */ 2893 dbg("%s mapbase %p phdrs %p PT_LOAD phdr %p vaddr %p dynamic %p", 2894 obj->path, obj->mapbase, obj->phdr, seg0, 2895 obj->relocbase + seg0->p_vaddr, obj->dynamic); 2896 2897 TAILQ_INSERT_TAIL(&obj_list, obj, next); 2898 obj_count++; 2899 obj_loads++; 2900 linkmap_add(obj); /* for GDB & dlinfo() */ 2901 max_stack_flags |= obj->stack_flags; 2902 2903 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, 0, 0, obj->path); 2904 return (0); 2905 } 2906 2907 Obj_Entry * 2908 obj_from_addr(const void *addr) 2909 { 2910 Obj_Entry *obj; 2911 2912 TAILQ_FOREACH(obj, &obj_list, next) { 2913 if (obj->marker) 2914 continue; 2915 if (addr < (void *) obj->mapbase) 2916 continue; 2917 if (addr < (void *)(obj->mapbase + obj->mapsize)) 2918 return obj; 2919 } 2920 return (NULL); 2921 } 2922 2923 static void 2924 preinit_main(void) 2925 { 2926 Elf_Addr *preinit_addr; 2927 int index; 2928 2929 preinit_addr = (Elf_Addr *)obj_main->preinit_array; 2930 if (preinit_addr == NULL) 2931 return; 2932 2933 for (index = 0; index < obj_main->preinit_array_num; index++) { 2934 if (preinit_addr[index] != 0 && preinit_addr[index] != 1) { 2935 dbg("calling preinit function for %s at %p", obj_main->path, 2936 (void *)preinit_addr[index]); 2937 LD_UTRACE(UTRACE_INIT_CALL, obj_main, (void *)preinit_addr[index], 2938 0, 0, obj_main->path); 2939 call_init_pointer(obj_main, preinit_addr[index]); 2940 } 2941 } 2942 } 2943 2944 /* 2945 * Call the finalization functions for each of the objects in "list" 2946 * belonging to the DAG of "root" and referenced once. If NULL "root" 2947 * is specified, every finalization function will be called regardless 2948 * of the reference count and the list elements won't be freed. All of 2949 * the objects are expected to have non-NULL fini functions. 2950 */ 2951 static void 2952 objlist_call_fini(Objlist *list, Obj_Entry *root, RtldLockState *lockstate) 2953 { 2954 Objlist_Entry *elm; 2955 struct dlerror_save *saved_msg; 2956 Elf_Addr *fini_addr; 2957 int index; 2958 2959 assert(root == NULL || root->refcount == 1); 2960 2961 if (root != NULL) 2962 root->doomed = true; 2963 2964 /* 2965 * Preserve the current error message since a fini function might 2966 * call into the dynamic linker and overwrite it. 2967 */ 2968 saved_msg = errmsg_save(); 2969 do { 2970 STAILQ_FOREACH(elm, list, link) { 2971 if (root != NULL && (elm->obj->refcount != 1 || 2972 objlist_find(&root->dagmembers, elm->obj) == NULL)) 2973 continue; 2974 /* Remove object from fini list to prevent recursive invocation. */ 2975 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 2976 /* Ensure that new references cannot be acquired. */ 2977 elm->obj->doomed = true; 2978 2979 hold_object(elm->obj); 2980 lock_release(rtld_bind_lock, lockstate); 2981 /* 2982 * It is legal to have both DT_FINI and DT_FINI_ARRAY defined. 2983 * When this happens, DT_FINI_ARRAY is processed first. 2984 */ 2985 fini_addr = (Elf_Addr *)elm->obj->fini_array; 2986 if (fini_addr != NULL && elm->obj->fini_array_num > 0) { 2987 for (index = elm->obj->fini_array_num - 1; index >= 0; 2988 index--) { 2989 if (fini_addr[index] != 0 && fini_addr[index] != 1) { 2990 dbg("calling fini function for %s at %p", 2991 elm->obj->path, (void *)fini_addr[index]); 2992 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, 2993 (void *)fini_addr[index], 0, 0, elm->obj->path); 2994 call_initfini_pointer(elm->obj, fini_addr[index]); 2995 } 2996 } 2997 } 2998 if (elm->obj->fini != (Elf_Addr)NULL) { 2999 dbg("calling fini function for %s at %p", elm->obj->path, 3000 (void *)elm->obj->fini); 3001 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, (void *)elm->obj->fini, 3002 0, 0, elm->obj->path); 3003 call_initfini_pointer(elm->obj, elm->obj->fini); 3004 } 3005 wlock_acquire(rtld_bind_lock, lockstate); 3006 unhold_object(elm->obj); 3007 /* No need to free anything if process is going down. */ 3008 if (root != NULL) 3009 free(elm); 3010 /* 3011 * We must restart the list traversal after every fini call 3012 * because a dlclose() call from the fini function or from 3013 * another thread might have modified the reference counts. 3014 */ 3015 break; 3016 } 3017 } while (elm != NULL); 3018 errmsg_restore(saved_msg); 3019 } 3020 3021 /* 3022 * Call the initialization functions for each of the objects in 3023 * "list". All of the objects are expected to have non-NULL init 3024 * functions. 3025 */ 3026 static void 3027 objlist_call_init(Objlist *list, RtldLockState *lockstate) 3028 { 3029 Objlist_Entry *elm; 3030 Obj_Entry *obj; 3031 struct dlerror_save *saved_msg; 3032 Elf_Addr *init_addr; 3033 void (*reg)(void (*)(void)); 3034 int index; 3035 3036 /* 3037 * Clean init_scanned flag so that objects can be rechecked and 3038 * possibly initialized earlier if any of vectors called below 3039 * cause the change by using dlopen. 3040 */ 3041 TAILQ_FOREACH(obj, &obj_list, next) { 3042 if (obj->marker) 3043 continue; 3044 obj->init_scanned = false; 3045 } 3046 3047 /* 3048 * Preserve the current error message since an init function might 3049 * call into the dynamic linker and overwrite it. 3050 */ 3051 saved_msg = errmsg_save(); 3052 STAILQ_FOREACH(elm, list, link) { 3053 if (elm->obj->init_done) /* Initialized early. */ 3054 continue; 3055 /* 3056 * Race: other thread might try to use this object before current 3057 * one completes the initialization. Not much can be done here 3058 * without better locking. 3059 */ 3060 elm->obj->init_done = true; 3061 hold_object(elm->obj); 3062 reg = NULL; 3063 if (elm->obj == obj_main && obj_main->crt_no_init) { 3064 reg = (void (*)(void (*)(void)))get_program_var_addr( 3065 "__libc_atexit", lockstate); 3066 } 3067 lock_release(rtld_bind_lock, lockstate); 3068 if (reg != NULL) { 3069 reg(rtld_exit); 3070 rtld_exit_ptr = rtld_nop_exit; 3071 } 3072 3073 /* 3074 * It is legal to have both DT_INIT and DT_INIT_ARRAY defined. 3075 * When this happens, DT_INIT is processed first. 3076 */ 3077 if (elm->obj->init != (Elf_Addr)NULL) { 3078 dbg("calling init function for %s at %p", elm->obj->path, 3079 (void *)elm->obj->init); 3080 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, (void *)elm->obj->init, 3081 0, 0, elm->obj->path); 3082 call_init_pointer(elm->obj, elm->obj->init); 3083 } 3084 init_addr = (Elf_Addr *)elm->obj->init_array; 3085 if (init_addr != NULL) { 3086 for (index = 0; index < elm->obj->init_array_num; index++) { 3087 if (init_addr[index] != 0 && init_addr[index] != 1) { 3088 dbg("calling init function for %s at %p", elm->obj->path, 3089 (void *)init_addr[index]); 3090 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, 3091 (void *)init_addr[index], 0, 0, elm->obj->path); 3092 call_init_pointer(elm->obj, init_addr[index]); 3093 } 3094 } 3095 } 3096 wlock_acquire(rtld_bind_lock, lockstate); 3097 unhold_object(elm->obj); 3098 } 3099 errmsg_restore(saved_msg); 3100 } 3101 3102 static void 3103 objlist_clear(Objlist *list) 3104 { 3105 Objlist_Entry *elm; 3106 3107 while (!STAILQ_EMPTY(list)) { 3108 elm = STAILQ_FIRST(list); 3109 STAILQ_REMOVE_HEAD(list, link); 3110 free(elm); 3111 } 3112 } 3113 3114 static Objlist_Entry * 3115 objlist_find(Objlist *list, const Obj_Entry *obj) 3116 { 3117 Objlist_Entry *elm; 3118 3119 STAILQ_FOREACH(elm, list, link) 3120 if (elm->obj == obj) 3121 return elm; 3122 return (NULL); 3123 } 3124 3125 static void 3126 objlist_init(Objlist *list) 3127 { 3128 STAILQ_INIT(list); 3129 } 3130 3131 static void 3132 objlist_push_head(Objlist *list, Obj_Entry *obj) 3133 { 3134 Objlist_Entry *elm; 3135 3136 elm = NEW(Objlist_Entry); 3137 elm->obj = obj; 3138 STAILQ_INSERT_HEAD(list, elm, link); 3139 } 3140 3141 static void 3142 objlist_push_tail(Objlist *list, Obj_Entry *obj) 3143 { 3144 Objlist_Entry *elm; 3145 3146 elm = NEW(Objlist_Entry); 3147 elm->obj = obj; 3148 STAILQ_INSERT_TAIL(list, elm, link); 3149 } 3150 3151 static void 3152 objlist_put_after(Objlist *list, Obj_Entry *listobj, Obj_Entry *obj) 3153 { 3154 Objlist_Entry *elm, *listelm; 3155 3156 STAILQ_FOREACH(listelm, list, link) { 3157 if (listelm->obj == listobj) 3158 break; 3159 } 3160 elm = NEW(Objlist_Entry); 3161 elm->obj = obj; 3162 if (listelm != NULL) 3163 STAILQ_INSERT_AFTER(list, listelm, elm, link); 3164 else 3165 STAILQ_INSERT_TAIL(list, elm, link); 3166 } 3167 3168 static void 3169 objlist_remove(Objlist *list, Obj_Entry *obj) 3170 { 3171 Objlist_Entry *elm; 3172 3173 if ((elm = objlist_find(list, obj)) != NULL) { 3174 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 3175 free(elm); 3176 } 3177 } 3178 3179 /* 3180 * Relocate dag rooted in the specified object. 3181 * Returns 0 on success, or -1 on failure. 3182 */ 3183 3184 static int 3185 relocate_object_dag(Obj_Entry *root, bool bind_now, Obj_Entry *rtldobj, 3186 int flags, RtldLockState *lockstate) 3187 { 3188 Objlist_Entry *elm; 3189 int error; 3190 3191 error = 0; 3192 STAILQ_FOREACH(elm, &root->dagmembers, link) { 3193 error = relocate_object(elm->obj, bind_now, rtldobj, flags, 3194 lockstate); 3195 if (error == -1) 3196 break; 3197 } 3198 return (error); 3199 } 3200 3201 /* 3202 * Prepare for, or clean after, relocating an object marked with 3203 * DT_TEXTREL or DF_TEXTREL. Before relocating, all read-only 3204 * segments are remapped read-write. After relocations are done, the 3205 * segment's permissions are returned back to the modes specified in 3206 * the phdrs. If any relocation happened, or always for wired 3207 * program, COW is triggered. 3208 */ 3209 static int 3210 reloc_textrel_prot(Obj_Entry *obj, bool before) 3211 { 3212 const Elf_Phdr *ph; 3213 void *base; 3214 size_t l, sz; 3215 int prot; 3216 3217 for (l = obj->phsize / sizeof(*ph), ph = obj->phdr; l > 0; 3218 l--, ph++) { 3219 if (ph->p_type != PT_LOAD || (ph->p_flags & PF_W) != 0) 3220 continue; 3221 base = obj->relocbase + rtld_trunc_page(ph->p_vaddr); 3222 sz = rtld_round_page(ph->p_vaddr + ph->p_filesz) - 3223 rtld_trunc_page(ph->p_vaddr); 3224 prot = before ? (PROT_READ | PROT_WRITE) : 3225 convert_prot(ph->p_flags); 3226 if (mprotect(base, sz, prot) == -1) { 3227 _rtld_error("%s: Cannot write-%sable text segment: %s", 3228 obj->path, before ? "en" : "dis", 3229 rtld_strerror(errno)); 3230 return (-1); 3231 } 3232 } 3233 return (0); 3234 } 3235 3236 /* Process RELR relative relocations. */ 3237 static void 3238 reloc_relr(Obj_Entry *obj) 3239 { 3240 const Elf_Relr *relr, *relrlim; 3241 Elf_Addr *where; 3242 3243 relrlim = (const Elf_Relr *)((const char *)obj->relr + obj->relrsize); 3244 for (relr = obj->relr; relr < relrlim; relr++) { 3245 Elf_Relr entry = *relr; 3246 3247 if ((entry & 1) == 0) { 3248 where = (Elf_Addr *)(obj->relocbase + entry); 3249 *where++ += (Elf_Addr)obj->relocbase; 3250 } else { 3251 for (long i = 0; (entry >>= 1) != 0; i++) 3252 if ((entry & 1) != 0) 3253 where[i] += (Elf_Addr)obj->relocbase; 3254 where += CHAR_BIT * sizeof(Elf_Relr) - 1; 3255 } 3256 } 3257 } 3258 3259 /* 3260 * Relocate single object. 3261 * Returns 0 on success, or -1 on failure. 3262 */ 3263 static int 3264 relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, 3265 int flags, RtldLockState *lockstate) 3266 { 3267 3268 if (obj->relocated) 3269 return (0); 3270 obj->relocated = true; 3271 if (obj != rtldobj) 3272 dbg("relocating \"%s\"", obj->path); 3273 3274 if (obj->symtab == NULL || obj->strtab == NULL || 3275 !(obj->valid_hash_sysv || obj->valid_hash_gnu)) 3276 dbg("object %s has no run-time symbol table", obj->path); 3277 3278 /* There are relocations to the write-protected text segment. */ 3279 if (obj->textrel && reloc_textrel_prot(obj, true) != 0) 3280 return (-1); 3281 3282 /* Process the non-PLT non-IFUNC relocations. */ 3283 if (reloc_non_plt(obj, rtldobj, flags, lockstate)) 3284 return (-1); 3285 reloc_relr(obj); 3286 3287 /* Re-protected the text segment. */ 3288 if (obj->textrel && reloc_textrel_prot(obj, false) != 0) 3289 return (-1); 3290 3291 /* Set the special PLT or GOT entries. */ 3292 init_pltgot(obj); 3293 3294 /* Process the PLT relocations. */ 3295 if (reloc_plt(obj, flags, lockstate) == -1) 3296 return (-1); 3297 /* Relocate the jump slots if we are doing immediate binding. */ 3298 if ((obj->bind_now || bind_now) && reloc_jmpslots(obj, flags, 3299 lockstate) == -1) 3300 return (-1); 3301 3302 if (!obj->mainprog && obj_enforce_relro(obj) == -1) 3303 return (-1); 3304 3305 /* 3306 * Set up the magic number and version in the Obj_Entry. These 3307 * were checked in the crt1.o from the original ElfKit, so we 3308 * set them for backward compatibility. 3309 */ 3310 obj->magic = RTLD_MAGIC; 3311 obj->version = RTLD_VERSION; 3312 3313 return (0); 3314 } 3315 3316 /* 3317 * Relocate newly-loaded shared objects. The argument is a pointer to 3318 * the Obj_Entry for the first such object. All objects from the first 3319 * to the end of the list of objects are relocated. Returns 0 on success, 3320 * or -1 on failure. 3321 */ 3322 static int 3323 relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj, 3324 int flags, RtldLockState *lockstate) 3325 { 3326 Obj_Entry *obj; 3327 int error; 3328 3329 for (error = 0, obj = first; obj != NULL; 3330 obj = TAILQ_NEXT(obj, next)) { 3331 if (obj->marker) 3332 continue; 3333 error = relocate_object(obj, bind_now, rtldobj, flags, 3334 lockstate); 3335 if (error == -1) 3336 break; 3337 } 3338 return (error); 3339 } 3340 3341 /* 3342 * The handling of R_MACHINE_IRELATIVE relocations and jumpslots 3343 * referencing STT_GNU_IFUNC symbols is postponed till the other 3344 * relocations are done. The indirect functions specified as 3345 * ifunc are allowed to call other symbols, so we need to have 3346 * objects relocated before asking for resolution from indirects. 3347 * 3348 * The R_MACHINE_IRELATIVE slots are resolved in greedy fashion, 3349 * instead of the usual lazy handling of PLT slots. It is 3350 * consistent with how GNU does it. 3351 */ 3352 static int 3353 resolve_object_ifunc(Obj_Entry *obj, bool bind_now, int flags, 3354 RtldLockState *lockstate) 3355 { 3356 3357 if (obj->ifuncs_resolved) 3358 return (0); 3359 obj->ifuncs_resolved = true; 3360 if (!obj->irelative && !obj->irelative_nonplt && 3361 !((obj->bind_now || bind_now) && obj->gnu_ifunc) && 3362 !obj->non_plt_gnu_ifunc) 3363 return (0); 3364 if (obj_disable_relro(obj) == -1 || 3365 (obj->irelative && reloc_iresolve(obj, lockstate) == -1) || 3366 (obj->irelative_nonplt && reloc_iresolve_nonplt(obj, 3367 lockstate) == -1) || 3368 ((obj->bind_now || bind_now) && obj->gnu_ifunc && 3369 reloc_gnu_ifunc(obj, flags, lockstate) == -1) || 3370 (obj->non_plt_gnu_ifunc && reloc_non_plt(obj, &obj_rtld, 3371 flags | SYMLOOK_IFUNC, lockstate) == -1) || 3372 obj_enforce_relro(obj) == -1) 3373 return (-1); 3374 return (0); 3375 } 3376 3377 static int 3378 initlist_objects_ifunc(Objlist *list, bool bind_now, int flags, 3379 RtldLockState *lockstate) 3380 { 3381 Objlist_Entry *elm; 3382 Obj_Entry *obj; 3383 3384 STAILQ_FOREACH(elm, list, link) { 3385 obj = elm->obj; 3386 if (obj->marker) 3387 continue; 3388 if (resolve_object_ifunc(obj, bind_now, flags, 3389 lockstate) == -1) 3390 return (-1); 3391 } 3392 return (0); 3393 } 3394 3395 /* 3396 * Cleanup procedure. It will be called (by the atexit mechanism) just 3397 * before the process exits. 3398 */ 3399 static void 3400 rtld_exit(void) 3401 { 3402 RtldLockState lockstate; 3403 3404 wlock_acquire(rtld_bind_lock, &lockstate); 3405 dbg("rtld_exit()"); 3406 objlist_call_fini(&list_fini, NULL, &lockstate); 3407 /* No need to remove the items from the list, since we are exiting. */ 3408 if (!libmap_disable) 3409 lm_fini(); 3410 lock_release(rtld_bind_lock, &lockstate); 3411 } 3412 3413 static void 3414 rtld_nop_exit(void) 3415 { 3416 } 3417 3418 /* 3419 * Iterate over a search path, translate each element, and invoke the 3420 * callback on the result. 3421 */ 3422 static void * 3423 path_enumerate(const char *path, path_enum_proc callback, 3424 const char *refobj_path, void *arg) 3425 { 3426 const char *trans; 3427 if (path == NULL) 3428 return (NULL); 3429 3430 path += strspn(path, ":;"); 3431 while (*path != '\0') { 3432 size_t len; 3433 char *res; 3434 3435 len = strcspn(path, ":;"); 3436 trans = lm_findn(refobj_path, path, len); 3437 if (trans) 3438 res = callback(trans, strlen(trans), arg); 3439 else 3440 res = callback(path, len, arg); 3441 3442 if (res != NULL) 3443 return (res); 3444 3445 path += len; 3446 path += strspn(path, ":;"); 3447 } 3448 3449 return (NULL); 3450 } 3451 3452 struct try_library_args { 3453 const char *name; 3454 size_t namelen; 3455 char *buffer; 3456 size_t buflen; 3457 int fd; 3458 }; 3459 3460 static void * 3461 try_library_path(const char *dir, size_t dirlen, void *param) 3462 { 3463 struct try_library_args *arg; 3464 int fd; 3465 3466 arg = param; 3467 if (*dir == '/' || trust) { 3468 char *pathname; 3469 3470 if (dirlen + 1 + arg->namelen + 1 > arg->buflen) 3471 return (NULL); 3472 3473 pathname = arg->buffer; 3474 strncpy(pathname, dir, dirlen); 3475 pathname[dirlen] = '/'; 3476 strcpy(pathname + dirlen + 1, arg->name); 3477 3478 dbg(" Trying \"%s\"", pathname); 3479 fd = open(pathname, O_RDONLY | O_CLOEXEC | O_VERIFY); 3480 if (fd >= 0) { 3481 dbg(" Opened \"%s\", fd %d", pathname, fd); 3482 pathname = xmalloc(dirlen + 1 + arg->namelen + 1); 3483 strcpy(pathname, arg->buffer); 3484 arg->fd = fd; 3485 return (pathname); 3486 } else { 3487 dbg(" Failed to open \"%s\": %s", 3488 pathname, rtld_strerror(errno)); 3489 } 3490 } 3491 return (NULL); 3492 } 3493 3494 static char * 3495 search_library_path(const char *name, const char *path, 3496 const char *refobj_path, int *fdp) 3497 { 3498 char *p; 3499 struct try_library_args arg; 3500 3501 if (path == NULL) 3502 return (NULL); 3503 3504 arg.name = name; 3505 arg.namelen = strlen(name); 3506 arg.buffer = xmalloc(PATH_MAX); 3507 arg.buflen = PATH_MAX; 3508 arg.fd = -1; 3509 3510 p = path_enumerate(path, try_library_path, refobj_path, &arg); 3511 *fdp = arg.fd; 3512 3513 free(arg.buffer); 3514 3515 return (p); 3516 } 3517 3518 3519 /* 3520 * Finds the library with the given name using the directory descriptors 3521 * listed in the LD_LIBRARY_PATH_FDS environment variable. 3522 * 3523 * Returns a freshly-opened close-on-exec file descriptor for the library, 3524 * or -1 if the library cannot be found. 3525 */ 3526 static char * 3527 search_library_pathfds(const char *name, const char *path, int *fdp) 3528 { 3529 char *envcopy, *fdstr, *found, *last_token; 3530 size_t len; 3531 int dirfd, fd; 3532 3533 dbg("%s('%s', '%s', fdp)", __func__, name, path); 3534 3535 /* Don't load from user-specified libdirs into setuid binaries. */ 3536 if (!trust) 3537 return (NULL); 3538 3539 /* We can't do anything if LD_LIBRARY_PATH_FDS isn't set. */ 3540 if (path == NULL) 3541 return (NULL); 3542 3543 /* LD_LIBRARY_PATH_FDS only works with relative paths. */ 3544 if (name[0] == '/') { 3545 dbg("Absolute path (%s) passed to %s", name, __func__); 3546 return (NULL); 3547 } 3548 3549 /* 3550 * Use strtok_r() to walk the FD:FD:FD list. This requires a local 3551 * copy of the path, as strtok_r rewrites separator tokens 3552 * with '\0'. 3553 */ 3554 found = NULL; 3555 envcopy = xstrdup(path); 3556 for (fdstr = strtok_r(envcopy, ":", &last_token); fdstr != NULL; 3557 fdstr = strtok_r(NULL, ":", &last_token)) { 3558 dirfd = parse_integer(fdstr); 3559 if (dirfd < 0) { 3560 _rtld_error("failed to parse directory FD: '%s'", 3561 fdstr); 3562 break; 3563 } 3564 fd = __sys_openat(dirfd, name, O_RDONLY | O_CLOEXEC | O_VERIFY); 3565 if (fd >= 0) { 3566 *fdp = fd; 3567 len = strlen(fdstr) + strlen(name) + 3; 3568 found = xmalloc(len); 3569 if (rtld_snprintf(found, len, "#%d/%s", dirfd, name) < 0) { 3570 _rtld_error("error generating '%d/%s'", 3571 dirfd, name); 3572 rtld_die(); 3573 } 3574 dbg("open('%s') => %d", found, fd); 3575 break; 3576 } 3577 } 3578 free(envcopy); 3579 3580 return (found); 3581 } 3582 3583 3584 int 3585 dlclose(void *handle) 3586 { 3587 RtldLockState lockstate; 3588 int error; 3589 3590 wlock_acquire(rtld_bind_lock, &lockstate); 3591 error = dlclose_locked(handle, &lockstate); 3592 lock_release(rtld_bind_lock, &lockstate); 3593 return (error); 3594 } 3595 3596 static int 3597 dlclose_locked(void *handle, RtldLockState *lockstate) 3598 { 3599 Obj_Entry *root; 3600 3601 root = dlcheck(handle); 3602 if (root == NULL) 3603 return (-1); 3604 LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount, 3605 root->path); 3606 3607 /* Unreference the object and its dependencies. */ 3608 root->dl_refcount--; 3609 3610 if (root->refcount == 1) { 3611 /* 3612 * The object will be no longer referenced, so we must unload it. 3613 * First, call the fini functions. 3614 */ 3615 objlist_call_fini(&list_fini, root, lockstate); 3616 3617 unref_dag(root); 3618 3619 /* Finish cleaning up the newly-unreferenced objects. */ 3620 GDB_STATE(RT_DELETE,&root->linkmap); 3621 unload_object(root, lockstate); 3622 GDB_STATE(RT_CONSISTENT,NULL); 3623 } else 3624 unref_dag(root); 3625 3626 LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL); 3627 return (0); 3628 } 3629 3630 char * 3631 dlerror(void) 3632 { 3633 if (*(lockinfo.dlerror_seen()) != 0) 3634 return (NULL); 3635 *lockinfo.dlerror_seen() = 1; 3636 return (lockinfo.dlerror_loc()); 3637 } 3638 3639 /* 3640 * This function is deprecated and has no effect. 3641 */ 3642 void 3643 dllockinit(void *context, 3644 void *(*_lock_create)(void *context) __unused, 3645 void (*_rlock_acquire)(void *lock) __unused, 3646 void (*_wlock_acquire)(void *lock) __unused, 3647 void (*_lock_release)(void *lock) __unused, 3648 void (*_lock_destroy)(void *lock) __unused, 3649 void (*context_destroy)(void *context)) 3650 { 3651 static void *cur_context; 3652 static void (*cur_context_destroy)(void *); 3653 3654 /* Just destroy the context from the previous call, if necessary. */ 3655 if (cur_context_destroy != NULL) 3656 cur_context_destroy(cur_context); 3657 cur_context = context; 3658 cur_context_destroy = context_destroy; 3659 } 3660 3661 void * 3662 dlopen(const char *name, int mode) 3663 { 3664 3665 return (rtld_dlopen(name, -1, mode)); 3666 } 3667 3668 void * 3669 fdlopen(int fd, int mode) 3670 { 3671 3672 return (rtld_dlopen(NULL, fd, mode)); 3673 } 3674 3675 static void * 3676 rtld_dlopen(const char *name, int fd, int mode) 3677 { 3678 RtldLockState lockstate; 3679 int lo_flags; 3680 3681 LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name); 3682 ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1"; 3683 if (ld_tracing != NULL) { 3684 rlock_acquire(rtld_bind_lock, &lockstate); 3685 if (sigsetjmp(lockstate.env, 0) != 0) 3686 lock_upgrade(rtld_bind_lock, &lockstate); 3687 environ = __DECONST(char **, *get_program_var_addr("environ", &lockstate)); 3688 lock_release(rtld_bind_lock, &lockstate); 3689 } 3690 lo_flags = RTLD_LO_DLOPEN; 3691 if (mode & RTLD_NODELETE) 3692 lo_flags |= RTLD_LO_NODELETE; 3693 if (mode & RTLD_NOLOAD) 3694 lo_flags |= RTLD_LO_NOLOAD; 3695 if (mode & RTLD_DEEPBIND) 3696 lo_flags |= RTLD_LO_DEEPBIND; 3697 if (ld_tracing != NULL) 3698 lo_flags |= RTLD_LO_TRACE | RTLD_LO_IGNSTLS; 3699 3700 return (dlopen_object(name, fd, obj_main, lo_flags, 3701 mode & (RTLD_MODEMASK | RTLD_GLOBAL), NULL)); 3702 } 3703 3704 static void 3705 dlopen_cleanup(Obj_Entry *obj, RtldLockState *lockstate) 3706 { 3707 3708 obj->dl_refcount--; 3709 unref_dag(obj); 3710 if (obj->refcount == 0) 3711 unload_object(obj, lockstate); 3712 } 3713 3714 static Obj_Entry * 3715 dlopen_object(const char *name, int fd, Obj_Entry *refobj, int lo_flags, 3716 int mode, RtldLockState *lockstate) 3717 { 3718 Obj_Entry *obj; 3719 Objlist initlist; 3720 RtldLockState mlockstate; 3721 int result; 3722 3723 dbg("dlopen_object name \"%s\" fd %d refobj \"%s\" lo_flags %#x mode %#x", 3724 name != NULL ? name : "<null>", fd, refobj == NULL ? "<null>" : 3725 refobj->path, lo_flags, mode); 3726 objlist_init(&initlist); 3727 3728 if (lockstate == NULL && !(lo_flags & RTLD_LO_EARLY)) { 3729 wlock_acquire(rtld_bind_lock, &mlockstate); 3730 lockstate = &mlockstate; 3731 } 3732 GDB_STATE(RT_ADD,NULL); 3733 3734 obj = NULL; 3735 if (name == NULL && fd == -1) { 3736 obj = obj_main; 3737 obj->refcount++; 3738 } else { 3739 obj = load_object(name, fd, refobj, lo_flags); 3740 } 3741 3742 if (obj) { 3743 obj->dl_refcount++; 3744 if (mode & RTLD_GLOBAL && objlist_find(&list_global, obj) == NULL) 3745 objlist_push_tail(&list_global, obj); 3746 3747 if (!obj->init_done) { 3748 /* We loaded something new and have to init something. */ 3749 if ((lo_flags & RTLD_LO_DEEPBIND) != 0) 3750 obj->deepbind = true; 3751 result = 0; 3752 if ((lo_flags & (RTLD_LO_EARLY | RTLD_LO_IGNSTLS)) == 0 && 3753 obj->static_tls && !allocate_tls_offset(obj)) { 3754 _rtld_error("%s: No space available " 3755 "for static Thread Local Storage", obj->path); 3756 result = -1; 3757 } 3758 if (result != -1) 3759 result = load_needed_objects(obj, lo_flags & (RTLD_LO_DLOPEN | 3760 RTLD_LO_EARLY | RTLD_LO_IGNSTLS | RTLD_LO_TRACE)); 3761 init_dag(obj); 3762 ref_dag(obj); 3763 if (result != -1) 3764 result = rtld_verify_versions(&obj->dagmembers); 3765 if (result != -1 && ld_tracing) 3766 goto trace; 3767 if (result == -1 || relocate_object_dag(obj, 3768 (mode & RTLD_MODEMASK) == RTLD_NOW, &obj_rtld, 3769 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 3770 lockstate) == -1) { 3771 dlopen_cleanup(obj, lockstate); 3772 obj = NULL; 3773 } else if (lo_flags & RTLD_LO_EARLY) { 3774 /* 3775 * Do not call the init functions for early loaded 3776 * filtees. The image is still not initialized enough 3777 * for them to work. 3778 * 3779 * Our object is found by the global object list and 3780 * will be ordered among all init calls done right 3781 * before transferring control to main. 3782 */ 3783 } else { 3784 /* Make list of init functions to call. */ 3785 initlist_add_objects(obj, obj, &initlist); 3786 } 3787 /* 3788 * Process all no_delete or global objects here, given 3789 * them own DAGs to prevent their dependencies from being 3790 * unloaded. This has to be done after we have loaded all 3791 * of the dependencies, so that we do not miss any. 3792 */ 3793 if (obj != NULL) 3794 process_z(obj); 3795 } else { 3796 /* 3797 * Bump the reference counts for objects on this DAG. If 3798 * this is the first dlopen() call for the object that was 3799 * already loaded as a dependency, initialize the dag 3800 * starting at it. 3801 */ 3802 init_dag(obj); 3803 ref_dag(obj); 3804 3805 if ((lo_flags & RTLD_LO_TRACE) != 0) 3806 goto trace; 3807 } 3808 if (obj != NULL && ((lo_flags & RTLD_LO_NODELETE) != 0 || 3809 obj->z_nodelete) && !obj->ref_nodel) { 3810 dbg("obj %s nodelete", obj->path); 3811 ref_dag(obj); 3812 obj->z_nodelete = obj->ref_nodel = true; 3813 } 3814 } 3815 3816 LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0, 3817 name); 3818 GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL); 3819 3820 if ((lo_flags & RTLD_LO_EARLY) == 0) { 3821 map_stacks_exec(lockstate); 3822 if (obj != NULL) 3823 distribute_static_tls(&initlist, lockstate); 3824 } 3825 3826 if (initlist_objects_ifunc(&initlist, (mode & RTLD_MODEMASK) == RTLD_NOW, 3827 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 3828 lockstate) == -1) { 3829 objlist_clear(&initlist); 3830 dlopen_cleanup(obj, lockstate); 3831 if (lockstate == &mlockstate) 3832 lock_release(rtld_bind_lock, lockstate); 3833 return (NULL); 3834 } 3835 3836 if (!(lo_flags & RTLD_LO_EARLY)) { 3837 /* Call the init functions. */ 3838 objlist_call_init(&initlist, lockstate); 3839 } 3840 objlist_clear(&initlist); 3841 if (lockstate == &mlockstate) 3842 lock_release(rtld_bind_lock, lockstate); 3843 return (obj); 3844 trace: 3845 trace_loaded_objects(obj, false); 3846 if (lockstate == &mlockstate) 3847 lock_release(rtld_bind_lock, lockstate); 3848 exit(0); 3849 } 3850 3851 static void * 3852 do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve, 3853 int flags) 3854 { 3855 DoneList donelist; 3856 const Obj_Entry *obj, *defobj; 3857 const Elf_Sym *def; 3858 SymLook req; 3859 RtldLockState lockstate; 3860 tls_index ti; 3861 void *sym; 3862 int res; 3863 3864 def = NULL; 3865 defobj = NULL; 3866 symlook_init(&req, name); 3867 req.ventry = ve; 3868 req.flags = flags | SYMLOOK_IN_PLT; 3869 req.lockstate = &lockstate; 3870 3871 LD_UTRACE(UTRACE_DLSYM_START, handle, NULL, 0, 0, name); 3872 rlock_acquire(rtld_bind_lock, &lockstate); 3873 if (sigsetjmp(lockstate.env, 0) != 0) 3874 lock_upgrade(rtld_bind_lock, &lockstate); 3875 if (handle == NULL || handle == RTLD_NEXT || 3876 handle == RTLD_DEFAULT || handle == RTLD_SELF) { 3877 3878 if ((obj = obj_from_addr(retaddr)) == NULL) { 3879 _rtld_error("Cannot determine caller's shared object"); 3880 lock_release(rtld_bind_lock, &lockstate); 3881 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 3882 return (NULL); 3883 } 3884 if (handle == NULL) { /* Just the caller's shared object. */ 3885 res = symlook_obj(&req, obj); 3886 if (res == 0) { 3887 def = req.sym_out; 3888 defobj = req.defobj_out; 3889 } 3890 } else if (handle == RTLD_NEXT || /* Objects after caller's */ 3891 handle == RTLD_SELF) { /* ... caller included */ 3892 if (handle == RTLD_NEXT) 3893 obj = globallist_next(obj); 3894 for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 3895 if (obj->marker) 3896 continue; 3897 res = symlook_obj(&req, obj); 3898 if (res == 0) { 3899 if (def == NULL || (ld_dynamic_weak && 3900 ELF_ST_BIND(req.sym_out->st_info) != STB_WEAK)) { 3901 def = req.sym_out; 3902 defobj = req.defobj_out; 3903 if (!ld_dynamic_weak || 3904 ELF_ST_BIND(def->st_info) != STB_WEAK) 3905 break; 3906 } 3907 } 3908 } 3909 /* 3910 * Search the dynamic linker itself, and possibly resolve the 3911 * symbol from there. This is how the application links to 3912 * dynamic linker services such as dlopen. 3913 * Note that we ignore ld_dynamic_weak == false case, 3914 * always overriding weak symbols by rtld definitions. 3915 */ 3916 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 3917 res = symlook_obj(&req, &obj_rtld); 3918 if (res == 0) { 3919 def = req.sym_out; 3920 defobj = req.defobj_out; 3921 } 3922 } 3923 } else { 3924 assert(handle == RTLD_DEFAULT); 3925 res = symlook_default(&req, obj); 3926 if (res == 0) { 3927 defobj = req.defobj_out; 3928 def = req.sym_out; 3929 } 3930 } 3931 } else { 3932 if ((obj = dlcheck(handle)) == NULL) { 3933 lock_release(rtld_bind_lock, &lockstate); 3934 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 3935 return (NULL); 3936 } 3937 3938 donelist_init(&donelist); 3939 if (obj->mainprog) { 3940 /* Handle obtained by dlopen(NULL, ...) implies global scope. */ 3941 res = symlook_global(&req, &donelist); 3942 if (res == 0) { 3943 def = req.sym_out; 3944 defobj = req.defobj_out; 3945 } 3946 /* 3947 * Search the dynamic linker itself, and possibly resolve the 3948 * symbol from there. This is how the application links to 3949 * dynamic linker services such as dlopen. 3950 */ 3951 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 3952 res = symlook_obj(&req, &obj_rtld); 3953 if (res == 0) { 3954 def = req.sym_out; 3955 defobj = req.defobj_out; 3956 } 3957 } 3958 } 3959 else { 3960 /* Search the whole DAG rooted at the given object. */ 3961 res = symlook_list(&req, &obj->dagmembers, &donelist); 3962 if (res == 0) { 3963 def = req.sym_out; 3964 defobj = req.defobj_out; 3965 } 3966 } 3967 } 3968 3969 if (def != NULL) { 3970 lock_release(rtld_bind_lock, &lockstate); 3971 3972 /* 3973 * The value required by the caller is derived from the value 3974 * of the symbol. this is simply the relocated value of the 3975 * symbol. 3976 */ 3977 if (ELF_ST_TYPE(def->st_info) == STT_FUNC) 3978 sym = make_function_pointer(def, defobj); 3979 else if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 3980 sym = rtld_resolve_ifunc(defobj, def); 3981 else if (ELF_ST_TYPE(def->st_info) == STT_TLS) { 3982 ti.ti_module = defobj->tlsindex; 3983 ti.ti_offset = def->st_value; 3984 sym = __tls_get_addr(&ti); 3985 } else 3986 sym = defobj->relocbase + def->st_value; 3987 LD_UTRACE(UTRACE_DLSYM_STOP, handle, sym, 0, 0, name); 3988 return (sym); 3989 } 3990 3991 _rtld_error("Undefined symbol \"%s%s%s\"", name, ve != NULL ? "@" : "", 3992 ve != NULL ? ve->name : ""); 3993 lock_release(rtld_bind_lock, &lockstate); 3994 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 3995 return (NULL); 3996 } 3997 3998 void * 3999 dlsym(void *handle, const char *name) 4000 { 4001 return (do_dlsym(handle, name, __builtin_return_address(0), NULL, 4002 SYMLOOK_DLSYM)); 4003 } 4004 4005 dlfunc_t 4006 dlfunc(void *handle, const char *name) 4007 { 4008 union { 4009 void *d; 4010 dlfunc_t f; 4011 } rv; 4012 4013 rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL, 4014 SYMLOOK_DLSYM); 4015 return (rv.f); 4016 } 4017 4018 void * 4019 dlvsym(void *handle, const char *name, const char *version) 4020 { 4021 Ver_Entry ventry; 4022 4023 ventry.name = version; 4024 ventry.file = NULL; 4025 ventry.hash = elf_hash(version); 4026 ventry.flags= 0; 4027 return (do_dlsym(handle, name, __builtin_return_address(0), &ventry, 4028 SYMLOOK_DLSYM)); 4029 } 4030 4031 int 4032 _rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info) 4033 { 4034 const Obj_Entry *obj; 4035 RtldLockState lockstate; 4036 4037 rlock_acquire(rtld_bind_lock, &lockstate); 4038 obj = obj_from_addr(addr); 4039 if (obj == NULL) { 4040 _rtld_error("No shared object contains address"); 4041 lock_release(rtld_bind_lock, &lockstate); 4042 return (0); 4043 } 4044 rtld_fill_dl_phdr_info(obj, phdr_info); 4045 lock_release(rtld_bind_lock, &lockstate); 4046 return (1); 4047 } 4048 4049 int 4050 dladdr(const void *addr, Dl_info *info) 4051 { 4052 const Obj_Entry *obj; 4053 const Elf_Sym *def; 4054 void *symbol_addr; 4055 unsigned long symoffset; 4056 RtldLockState lockstate; 4057 4058 rlock_acquire(rtld_bind_lock, &lockstate); 4059 obj = obj_from_addr(addr); 4060 if (obj == NULL) { 4061 _rtld_error("No shared object contains address"); 4062 lock_release(rtld_bind_lock, &lockstate); 4063 return (0); 4064 } 4065 info->dli_fname = obj->path; 4066 info->dli_fbase = obj->mapbase; 4067 info->dli_saddr = (void *)0; 4068 info->dli_sname = NULL; 4069 4070 /* 4071 * Walk the symbol list looking for the symbol whose address is 4072 * closest to the address sent in. 4073 */ 4074 for (symoffset = 0; symoffset < obj->dynsymcount; symoffset++) { 4075 def = obj->symtab + symoffset; 4076 4077 /* 4078 * For skip the symbol if st_shndx is either SHN_UNDEF or 4079 * SHN_COMMON. 4080 */ 4081 if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON) 4082 continue; 4083 4084 /* 4085 * If the symbol is greater than the specified address, or if it 4086 * is further away from addr than the current nearest symbol, 4087 * then reject it. 4088 */ 4089 symbol_addr = obj->relocbase + def->st_value; 4090 if (symbol_addr > addr || symbol_addr < info->dli_saddr) 4091 continue; 4092 4093 /* Update our idea of the nearest symbol. */ 4094 info->dli_sname = obj->strtab + def->st_name; 4095 info->dli_saddr = symbol_addr; 4096 4097 /* Exact match? */ 4098 if (info->dli_saddr == addr) 4099 break; 4100 } 4101 lock_release(rtld_bind_lock, &lockstate); 4102 return (1); 4103 } 4104 4105 int 4106 dlinfo(void *handle, int request, void *p) 4107 { 4108 const Obj_Entry *obj; 4109 RtldLockState lockstate; 4110 int error; 4111 4112 rlock_acquire(rtld_bind_lock, &lockstate); 4113 4114 if (handle == NULL || handle == RTLD_SELF) { 4115 void *retaddr; 4116 4117 retaddr = __builtin_return_address(0); /* __GNUC__ only */ 4118 if ((obj = obj_from_addr(retaddr)) == NULL) 4119 _rtld_error("Cannot determine caller's shared object"); 4120 } else 4121 obj = dlcheck(handle); 4122 4123 if (obj == NULL) { 4124 lock_release(rtld_bind_lock, &lockstate); 4125 return (-1); 4126 } 4127 4128 error = 0; 4129 switch (request) { 4130 case RTLD_DI_LINKMAP: 4131 *((struct link_map const **)p) = &obj->linkmap; 4132 break; 4133 case RTLD_DI_ORIGIN: 4134 error = rtld_dirname(obj->path, p); 4135 break; 4136 4137 case RTLD_DI_SERINFOSIZE: 4138 case RTLD_DI_SERINFO: 4139 error = do_search_info(obj, request, (struct dl_serinfo *)p); 4140 break; 4141 4142 default: 4143 _rtld_error("Invalid request %d passed to dlinfo()", request); 4144 error = -1; 4145 } 4146 4147 lock_release(rtld_bind_lock, &lockstate); 4148 4149 return (error); 4150 } 4151 4152 static void 4153 rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info) 4154 { 4155 uintptr_t **dtvp; 4156 4157 phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase; 4158 phdr_info->dlpi_name = obj->path; 4159 phdr_info->dlpi_phdr = obj->phdr; 4160 phdr_info->dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]); 4161 phdr_info->dlpi_tls_modid = obj->tlsindex; 4162 dtvp = &_tcb_get()->tcb_dtv; 4163 phdr_info->dlpi_tls_data = (char *)tls_get_addr_slow(dtvp, 4164 obj->tlsindex, 0, true) + TLS_DTV_OFFSET; 4165 phdr_info->dlpi_adds = obj_loads; 4166 phdr_info->dlpi_subs = obj_loads - obj_count; 4167 } 4168 4169 int 4170 dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param) 4171 { 4172 struct dl_phdr_info phdr_info; 4173 Obj_Entry *obj, marker; 4174 RtldLockState bind_lockstate, phdr_lockstate; 4175 int error; 4176 4177 init_marker(&marker); 4178 error = 0; 4179 4180 wlock_acquire(rtld_phdr_lock, &phdr_lockstate); 4181 wlock_acquire(rtld_bind_lock, &bind_lockstate); 4182 for (obj = globallist_curr(TAILQ_FIRST(&obj_list)); obj != NULL;) { 4183 TAILQ_INSERT_AFTER(&obj_list, obj, &marker, next); 4184 rtld_fill_dl_phdr_info(obj, &phdr_info); 4185 hold_object(obj); 4186 lock_release(rtld_bind_lock, &bind_lockstate); 4187 4188 error = callback(&phdr_info, sizeof phdr_info, param); 4189 4190 wlock_acquire(rtld_bind_lock, &bind_lockstate); 4191 unhold_object(obj); 4192 obj = globallist_next(&marker); 4193 TAILQ_REMOVE(&obj_list, &marker, next); 4194 if (error != 0) { 4195 lock_release(rtld_bind_lock, &bind_lockstate); 4196 lock_release(rtld_phdr_lock, &phdr_lockstate); 4197 return (error); 4198 } 4199 } 4200 4201 if (error == 0) { 4202 rtld_fill_dl_phdr_info(&obj_rtld, &phdr_info); 4203 lock_release(rtld_bind_lock, &bind_lockstate); 4204 error = callback(&phdr_info, sizeof(phdr_info), param); 4205 } 4206 lock_release(rtld_phdr_lock, &phdr_lockstate); 4207 return (error); 4208 } 4209 4210 static void * 4211 fill_search_info(const char *dir, size_t dirlen, void *param) 4212 { 4213 struct fill_search_info_args *arg; 4214 4215 arg = param; 4216 4217 if (arg->request == RTLD_DI_SERINFOSIZE) { 4218 arg->serinfo->dls_cnt ++; 4219 arg->serinfo->dls_size += sizeof(struct dl_serpath) + dirlen + 1; 4220 } else { 4221 struct dl_serpath *s_entry; 4222 4223 s_entry = arg->serpath; 4224 s_entry->dls_name = arg->strspace; 4225 s_entry->dls_flags = arg->flags; 4226 4227 strncpy(arg->strspace, dir, dirlen); 4228 arg->strspace[dirlen] = '\0'; 4229 4230 arg->strspace += dirlen + 1; 4231 arg->serpath++; 4232 } 4233 4234 return (NULL); 4235 } 4236 4237 static int 4238 do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info) 4239 { 4240 struct dl_serinfo _info; 4241 struct fill_search_info_args args; 4242 4243 args.request = RTLD_DI_SERINFOSIZE; 4244 args.serinfo = &_info; 4245 4246 _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 4247 _info.dls_cnt = 0; 4248 4249 path_enumerate(obj->rpath, fill_search_info, NULL, &args); 4250 path_enumerate(ld_library_path, fill_search_info, NULL, &args); 4251 path_enumerate(obj->runpath, fill_search_info, NULL, &args); 4252 path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, &args); 4253 if (!obj->z_nodeflib) 4254 path_enumerate(ld_standard_library_path, fill_search_info, NULL, &args); 4255 4256 4257 if (request == RTLD_DI_SERINFOSIZE) { 4258 info->dls_size = _info.dls_size; 4259 info->dls_cnt = _info.dls_cnt; 4260 return (0); 4261 } 4262 4263 if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) { 4264 _rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()"); 4265 return (-1); 4266 } 4267 4268 args.request = RTLD_DI_SERINFO; 4269 args.serinfo = info; 4270 args.serpath = &info->dls_serpath[0]; 4271 args.strspace = (char *)&info->dls_serpath[_info.dls_cnt]; 4272 4273 args.flags = LA_SER_RUNPATH; 4274 if (path_enumerate(obj->rpath, fill_search_info, NULL, &args) != NULL) 4275 return (-1); 4276 4277 args.flags = LA_SER_LIBPATH; 4278 if (path_enumerate(ld_library_path, fill_search_info, NULL, &args) != NULL) 4279 return (-1); 4280 4281 args.flags = LA_SER_RUNPATH; 4282 if (path_enumerate(obj->runpath, fill_search_info, NULL, &args) != NULL) 4283 return (-1); 4284 4285 args.flags = LA_SER_CONFIG; 4286 if (path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, &args) 4287 != NULL) 4288 return (-1); 4289 4290 args.flags = LA_SER_DEFAULT; 4291 if (!obj->z_nodeflib && path_enumerate(ld_standard_library_path, 4292 fill_search_info, NULL, &args) != NULL) 4293 return (-1); 4294 return (0); 4295 } 4296 4297 static int 4298 rtld_dirname(const char *path, char *bname) 4299 { 4300 const char *endp; 4301 4302 /* Empty or NULL string gets treated as "." */ 4303 if (path == NULL || *path == '\0') { 4304 bname[0] = '.'; 4305 bname[1] = '\0'; 4306 return (0); 4307 } 4308 4309 /* Strip trailing slashes */ 4310 endp = path + strlen(path) - 1; 4311 while (endp > path && *endp == '/') 4312 endp--; 4313 4314 /* Find the start of the dir */ 4315 while (endp > path && *endp != '/') 4316 endp--; 4317 4318 /* Either the dir is "/" or there are no slashes */ 4319 if (endp == path) { 4320 bname[0] = *endp == '/' ? '/' : '.'; 4321 bname[1] = '\0'; 4322 return (0); 4323 } else { 4324 do { 4325 endp--; 4326 } while (endp > path && *endp == '/'); 4327 } 4328 4329 if (endp - path + 2 > PATH_MAX) 4330 { 4331 _rtld_error("Filename is too long: %s", path); 4332 return(-1); 4333 } 4334 4335 strncpy(bname, path, endp - path + 1); 4336 bname[endp - path + 1] = '\0'; 4337 return (0); 4338 } 4339 4340 static int 4341 rtld_dirname_abs(const char *path, char *base) 4342 { 4343 char *last; 4344 4345 if (realpath(path, base) == NULL) { 4346 _rtld_error("realpath \"%s\" failed (%s)", path, 4347 rtld_strerror(errno)); 4348 return (-1); 4349 } 4350 dbg("%s -> %s", path, base); 4351 last = strrchr(base, '/'); 4352 if (last == NULL) { 4353 _rtld_error("non-abs result from realpath \"%s\"", path); 4354 return (-1); 4355 } 4356 if (last != base) 4357 *last = '\0'; 4358 return (0); 4359 } 4360 4361 static void 4362 linkmap_add(Obj_Entry *obj) 4363 { 4364 struct link_map *l, *prev; 4365 4366 l = &obj->linkmap; 4367 l->l_name = obj->path; 4368 l->l_base = obj->mapbase; 4369 l->l_ld = obj->dynamic; 4370 l->l_addr = obj->relocbase; 4371 4372 if (r_debug.r_map == NULL) { 4373 r_debug.r_map = l; 4374 return; 4375 } 4376 4377 /* 4378 * Scan to the end of the list, but not past the entry for the 4379 * dynamic linker, which we want to keep at the very end. 4380 */ 4381 for (prev = r_debug.r_map; 4382 prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap; 4383 prev = prev->l_next) 4384 ; 4385 4386 /* Link in the new entry. */ 4387 l->l_prev = prev; 4388 l->l_next = prev->l_next; 4389 if (l->l_next != NULL) 4390 l->l_next->l_prev = l; 4391 prev->l_next = l; 4392 } 4393 4394 static void 4395 linkmap_delete(Obj_Entry *obj) 4396 { 4397 struct link_map *l; 4398 4399 l = &obj->linkmap; 4400 if (l->l_prev == NULL) { 4401 if ((r_debug.r_map = l->l_next) != NULL) 4402 l->l_next->l_prev = NULL; 4403 return; 4404 } 4405 4406 if ((l->l_prev->l_next = l->l_next) != NULL) 4407 l->l_next->l_prev = l->l_prev; 4408 } 4409 4410 /* 4411 * Function for the debugger to set a breakpoint on to gain control. 4412 * 4413 * The two parameters allow the debugger to easily find and determine 4414 * what the runtime loader is doing and to whom it is doing it. 4415 * 4416 * When the loadhook trap is hit (r_debug_state, set at program 4417 * initialization), the arguments can be found on the stack: 4418 * 4419 * +8 struct link_map *m 4420 * +4 struct r_debug *rd 4421 * +0 RetAddr 4422 */ 4423 void 4424 r_debug_state(struct r_debug* rd __unused, struct link_map *m __unused) 4425 { 4426 /* 4427 * The following is a hack to force the compiler to emit calls to 4428 * this function, even when optimizing. If the function is empty, 4429 * the compiler is not obliged to emit any code for calls to it, 4430 * even when marked __noinline. However, gdb depends on those 4431 * calls being made. 4432 */ 4433 __compiler_membar(); 4434 } 4435 4436 /* 4437 * A function called after init routines have completed. This can be used to 4438 * break before a program's entry routine is called, and can be used when 4439 * main is not available in the symbol table. 4440 */ 4441 void 4442 _r_debug_postinit(struct link_map *m __unused) 4443 { 4444 4445 /* See r_debug_state(). */ 4446 __compiler_membar(); 4447 } 4448 4449 static void 4450 release_object(Obj_Entry *obj) 4451 { 4452 4453 if (obj->holdcount > 0) { 4454 obj->unholdfree = true; 4455 return; 4456 } 4457 munmap(obj->mapbase, obj->mapsize); 4458 linkmap_delete(obj); 4459 obj_free(obj); 4460 } 4461 4462 /* 4463 * Get address of the pointer variable in the main program. 4464 * Prefer non-weak symbol over the weak one. 4465 */ 4466 static const void ** 4467 get_program_var_addr(const char *name, RtldLockState *lockstate) 4468 { 4469 SymLook req; 4470 DoneList donelist; 4471 4472 symlook_init(&req, name); 4473 req.lockstate = lockstate; 4474 donelist_init(&donelist); 4475 if (symlook_global(&req, &donelist) != 0) 4476 return (NULL); 4477 if (ELF_ST_TYPE(req.sym_out->st_info) == STT_FUNC) 4478 return ((const void **)make_function_pointer(req.sym_out, 4479 req.defobj_out)); 4480 else if (ELF_ST_TYPE(req.sym_out->st_info) == STT_GNU_IFUNC) 4481 return ((const void **)rtld_resolve_ifunc(req.defobj_out, req.sym_out)); 4482 else 4483 return ((const void **)(req.defobj_out->relocbase + 4484 req.sym_out->st_value)); 4485 } 4486 4487 /* 4488 * Set a pointer variable in the main program to the given value. This 4489 * is used to set key variables such as "environ" before any of the 4490 * init functions are called. 4491 */ 4492 static void 4493 set_program_var(const char *name, const void *value) 4494 { 4495 const void **addr; 4496 4497 if ((addr = get_program_var_addr(name, NULL)) != NULL) { 4498 dbg("\"%s\": *%p <-- %p", name, addr, value); 4499 *addr = value; 4500 } 4501 } 4502 4503 /* 4504 * Search the global objects, including dependencies and main object, 4505 * for the given symbol. 4506 */ 4507 static int 4508 symlook_global(SymLook *req, DoneList *donelist) 4509 { 4510 SymLook req1; 4511 const Objlist_Entry *elm; 4512 int res; 4513 4514 symlook_init_from_req(&req1, req); 4515 4516 /* Search all objects loaded at program start up. */ 4517 if (req->defobj_out == NULL || (ld_dynamic_weak && 4518 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK)) { 4519 res = symlook_list(&req1, &list_main, donelist); 4520 if (res == 0 && (!ld_dynamic_weak || req->defobj_out == NULL || 4521 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4522 req->sym_out = req1.sym_out; 4523 req->defobj_out = req1.defobj_out; 4524 assert(req->defobj_out != NULL); 4525 } 4526 } 4527 4528 /* Search all DAGs whose roots are RTLD_GLOBAL objects. */ 4529 STAILQ_FOREACH(elm, &list_global, link) { 4530 if (req->defobj_out != NULL && (!ld_dynamic_weak || 4531 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK)) 4532 break; 4533 res = symlook_list(&req1, &elm->obj->dagmembers, donelist); 4534 if (res == 0 && (req->defobj_out == NULL || 4535 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4536 req->sym_out = req1.sym_out; 4537 req->defobj_out = req1.defobj_out; 4538 assert(req->defobj_out != NULL); 4539 } 4540 } 4541 4542 return (req->sym_out != NULL ? 0 : ESRCH); 4543 } 4544 4545 /* 4546 * Given a symbol name in a referencing object, find the corresponding 4547 * definition of the symbol. Returns a pointer to the symbol, or NULL if 4548 * no definition was found. Returns a pointer to the Obj_Entry of the 4549 * defining object via the reference parameter DEFOBJ_OUT. 4550 */ 4551 static int 4552 symlook_default(SymLook *req, const Obj_Entry *refobj) 4553 { 4554 DoneList donelist; 4555 const Objlist_Entry *elm; 4556 SymLook req1; 4557 int res; 4558 4559 donelist_init(&donelist); 4560 symlook_init_from_req(&req1, req); 4561 4562 /* 4563 * Look first in the referencing object if linked symbolically, 4564 * and similarly handle protected symbols. 4565 */ 4566 res = symlook_obj(&req1, refobj); 4567 if (res == 0 && (refobj->symbolic || 4568 ELF_ST_VISIBILITY(req1.sym_out->st_other) == STV_PROTECTED)) { 4569 req->sym_out = req1.sym_out; 4570 req->defobj_out = req1.defobj_out; 4571 assert(req->defobj_out != NULL); 4572 } 4573 if (refobj->symbolic || req->defobj_out != NULL) 4574 donelist_check(&donelist, refobj); 4575 4576 if (!refobj->deepbind) 4577 symlook_global(req, &donelist); 4578 4579 /* Search all dlopened DAGs containing the referencing object. */ 4580 STAILQ_FOREACH(elm, &refobj->dldags, link) { 4581 if (req->sym_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->sym_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 if (refobj->deepbind) 4594 symlook_global(req, &donelist); 4595 4596 /* 4597 * Search the dynamic linker itself, and possibly resolve the 4598 * symbol from there. This is how the application links to 4599 * dynamic linker services such as dlopen. 4600 */ 4601 if (req->sym_out == NULL || 4602 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 4603 res = symlook_obj(&req1, &obj_rtld); 4604 if (res == 0) { 4605 req->sym_out = req1.sym_out; 4606 req->defobj_out = req1.defobj_out; 4607 assert(req->defobj_out != NULL); 4608 } 4609 } 4610 4611 return (req->sym_out != NULL ? 0 : ESRCH); 4612 } 4613 4614 static int 4615 symlook_list(SymLook *req, const Objlist *objlist, DoneList *dlp) 4616 { 4617 const Elf_Sym *def; 4618 const Obj_Entry *defobj; 4619 const Objlist_Entry *elm; 4620 SymLook req1; 4621 int res; 4622 4623 def = NULL; 4624 defobj = NULL; 4625 STAILQ_FOREACH(elm, objlist, link) { 4626 if (donelist_check(dlp, elm->obj)) 4627 continue; 4628 symlook_init_from_req(&req1, req); 4629 if ((res = symlook_obj(&req1, elm->obj)) == 0) { 4630 if (def == NULL || (ld_dynamic_weak && 4631 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4632 def = req1.sym_out; 4633 defobj = req1.defobj_out; 4634 if (!ld_dynamic_weak || ELF_ST_BIND(def->st_info) != STB_WEAK) 4635 break; 4636 } 4637 } 4638 } 4639 if (def != NULL) { 4640 req->sym_out = def; 4641 req->defobj_out = defobj; 4642 return (0); 4643 } 4644 return (ESRCH); 4645 } 4646 4647 /* 4648 * Search the chain of DAGS cointed to by the given Needed_Entry 4649 * for a symbol of the given name. Each DAG is scanned completely 4650 * before advancing to the next one. Returns a pointer to the symbol, 4651 * or NULL if no definition was found. 4652 */ 4653 static int 4654 symlook_needed(SymLook *req, const Needed_Entry *needed, DoneList *dlp) 4655 { 4656 const Elf_Sym *def; 4657 const Needed_Entry *n; 4658 const Obj_Entry *defobj; 4659 SymLook req1; 4660 int res; 4661 4662 def = NULL; 4663 defobj = NULL; 4664 symlook_init_from_req(&req1, req); 4665 for (n = needed; n != NULL; n = n->next) { 4666 if (n->obj == NULL || 4667 (res = symlook_list(&req1, &n->obj->dagmembers, dlp)) != 0) 4668 continue; 4669 if (def == NULL || (ld_dynamic_weak && 4670 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4671 def = req1.sym_out; 4672 defobj = req1.defobj_out; 4673 if (!ld_dynamic_weak || ELF_ST_BIND(def->st_info) != STB_WEAK) 4674 break; 4675 } 4676 } 4677 if (def != NULL) { 4678 req->sym_out = def; 4679 req->defobj_out = defobj; 4680 return (0); 4681 } 4682 return (ESRCH); 4683 } 4684 4685 static int 4686 symlook_obj_load_filtees(SymLook *req, SymLook *req1, const Obj_Entry *obj, 4687 Needed_Entry *needed) 4688 { 4689 DoneList donelist; 4690 int flags; 4691 4692 flags = (req->flags & SYMLOOK_EARLY) != 0 ? RTLD_LO_EARLY : 0; 4693 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 4694 donelist_init(&donelist); 4695 symlook_init_from_req(req1, req); 4696 return (symlook_needed(req1, needed, &donelist)); 4697 } 4698 4699 /* 4700 * Search the symbol table of a single shared object for a symbol of 4701 * the given name and version, if requested. Returns a pointer to the 4702 * symbol, or NULL if no definition was found. If the object is 4703 * filter, return filtered symbol from filtee. 4704 * 4705 * The symbol's hash value is passed in for efficiency reasons; that 4706 * eliminates many recomputations of the hash value. 4707 */ 4708 int 4709 symlook_obj(SymLook *req, const Obj_Entry *obj) 4710 { 4711 SymLook req1; 4712 int res, mres; 4713 4714 /* 4715 * If there is at least one valid hash at this point, we prefer to 4716 * use the faster GNU version if available. 4717 */ 4718 if (obj->valid_hash_gnu) 4719 mres = symlook_obj1_gnu(req, obj); 4720 else if (obj->valid_hash_sysv) 4721 mres = symlook_obj1_sysv(req, obj); 4722 else 4723 return (EINVAL); 4724 4725 if (mres == 0) { 4726 if (obj->needed_filtees != NULL) { 4727 res = symlook_obj_load_filtees(req, &req1, obj, 4728 obj->needed_filtees); 4729 if (res == 0) { 4730 req->sym_out = req1.sym_out; 4731 req->defobj_out = req1.defobj_out; 4732 } 4733 return (res); 4734 } 4735 if (obj->needed_aux_filtees != NULL) { 4736 res = symlook_obj_load_filtees(req, &req1, obj, 4737 obj->needed_aux_filtees); 4738 if (res == 0) { 4739 req->sym_out = req1.sym_out; 4740 req->defobj_out = req1.defobj_out; 4741 return (res); 4742 } 4743 } 4744 } 4745 return (mres); 4746 } 4747 4748 /* Symbol match routine common to both hash functions */ 4749 static bool 4750 matched_symbol(SymLook *req, const Obj_Entry *obj, Sym_Match_Result *result, 4751 const unsigned long symnum) 4752 { 4753 Elf_Versym verndx; 4754 const Elf_Sym *symp; 4755 const char *strp; 4756 4757 symp = obj->symtab + symnum; 4758 strp = obj->strtab + symp->st_name; 4759 4760 switch (ELF_ST_TYPE(symp->st_info)) { 4761 case STT_FUNC: 4762 case STT_NOTYPE: 4763 case STT_OBJECT: 4764 case STT_COMMON: 4765 case STT_GNU_IFUNC: 4766 if (symp->st_value == 0) 4767 return (false); 4768 /* fallthrough */ 4769 case STT_TLS: 4770 if (symp->st_shndx != SHN_UNDEF) 4771 break; 4772 else if (((req->flags & SYMLOOK_IN_PLT) == 0) && 4773 (ELF_ST_TYPE(symp->st_info) == STT_FUNC)) 4774 break; 4775 /* fallthrough */ 4776 default: 4777 return (false); 4778 } 4779 if (req->name[0] != strp[0] || strcmp(req->name, strp) != 0) 4780 return (false); 4781 4782 if (req->ventry == NULL) { 4783 if (obj->versyms != NULL) { 4784 verndx = VER_NDX(obj->versyms[symnum]); 4785 if (verndx > obj->vernum) { 4786 _rtld_error( 4787 "%s: symbol %s references wrong version %d", 4788 obj->path, obj->strtab + symnum, verndx); 4789 return (false); 4790 } 4791 /* 4792 * If we are not called from dlsym (i.e. this 4793 * is a normal relocation from unversioned 4794 * binary), accept the symbol immediately if 4795 * it happens to have first version after this 4796 * shared object became versioned. Otherwise, 4797 * if symbol is versioned and not hidden, 4798 * remember it. If it is the only symbol with 4799 * this name exported by the shared object, it 4800 * will be returned as a match by the calling 4801 * function. If symbol is global (verndx < 2) 4802 * accept it unconditionally. 4803 */ 4804 if ((req->flags & SYMLOOK_DLSYM) == 0 && 4805 verndx == VER_NDX_GIVEN) { 4806 result->sym_out = symp; 4807 return (true); 4808 } 4809 else if (verndx >= VER_NDX_GIVEN) { 4810 if ((obj->versyms[symnum] & VER_NDX_HIDDEN) 4811 == 0) { 4812 if (result->vsymp == NULL) 4813 result->vsymp = symp; 4814 result->vcount++; 4815 } 4816 return (false); 4817 } 4818 } 4819 result->sym_out = symp; 4820 return (true); 4821 } 4822 if (obj->versyms == NULL) { 4823 if (object_match_name(obj, req->ventry->name)) { 4824 _rtld_error("%s: object %s should provide version %s " 4825 "for symbol %s", obj_rtld.path, obj->path, 4826 req->ventry->name, obj->strtab + symnum); 4827 return (false); 4828 } 4829 } else { 4830 verndx = VER_NDX(obj->versyms[symnum]); 4831 if (verndx > obj->vernum) { 4832 _rtld_error("%s: symbol %s references wrong version %d", 4833 obj->path, obj->strtab + symnum, verndx); 4834 return (false); 4835 } 4836 if (obj->vertab[verndx].hash != req->ventry->hash || 4837 strcmp(obj->vertab[verndx].name, req->ventry->name)) { 4838 /* 4839 * Version does not match. Look if this is a 4840 * global symbol and if it is not hidden. If 4841 * global symbol (verndx < 2) is available, 4842 * use it. Do not return symbol if we are 4843 * called by dlvsym, because dlvsym looks for 4844 * a specific version and default one is not 4845 * what dlvsym wants. 4846 */ 4847 if ((req->flags & SYMLOOK_DLSYM) || 4848 (verndx >= VER_NDX_GIVEN) || 4849 (obj->versyms[symnum] & VER_NDX_HIDDEN)) 4850 return (false); 4851 } 4852 } 4853 result->sym_out = symp; 4854 return (true); 4855 } 4856 4857 /* 4858 * Search for symbol using SysV hash function. 4859 * obj->buckets is known not to be NULL at this point; the test for this was 4860 * performed with the obj->valid_hash_sysv assignment. 4861 */ 4862 static int 4863 symlook_obj1_sysv(SymLook *req, const Obj_Entry *obj) 4864 { 4865 unsigned long symnum; 4866 Sym_Match_Result matchres; 4867 4868 matchres.sym_out = NULL; 4869 matchres.vsymp = NULL; 4870 matchres.vcount = 0; 4871 4872 for (symnum = obj->buckets[req->hash % obj->nbuckets]; 4873 symnum != STN_UNDEF; symnum = obj->chains[symnum]) { 4874 if (symnum >= obj->nchains) 4875 return (ESRCH); /* Bad object */ 4876 4877 if (matched_symbol(req, obj, &matchres, symnum)) { 4878 req->sym_out = matchres.sym_out; 4879 req->defobj_out = obj; 4880 return (0); 4881 } 4882 } 4883 if (matchres.vcount == 1) { 4884 req->sym_out = matchres.vsymp; 4885 req->defobj_out = obj; 4886 return (0); 4887 } 4888 return (ESRCH); 4889 } 4890 4891 /* Search for symbol using GNU hash function */ 4892 static int 4893 symlook_obj1_gnu(SymLook *req, const Obj_Entry *obj) 4894 { 4895 Elf_Addr bloom_word; 4896 const Elf32_Word *hashval; 4897 Elf32_Word bucket; 4898 Sym_Match_Result matchres; 4899 unsigned int h1, h2; 4900 unsigned long symnum; 4901 4902 matchres.sym_out = NULL; 4903 matchres.vsymp = NULL; 4904 matchres.vcount = 0; 4905 4906 /* Pick right bitmask word from Bloom filter array */ 4907 bloom_word = obj->bloom_gnu[(req->hash_gnu / __ELF_WORD_SIZE) & 4908 obj->maskwords_bm_gnu]; 4909 4910 /* Calculate modulus word size of gnu hash and its derivative */ 4911 h1 = req->hash_gnu & (__ELF_WORD_SIZE - 1); 4912 h2 = ((req->hash_gnu >> obj->shift2_gnu) & (__ELF_WORD_SIZE - 1)); 4913 4914 /* Filter out the "definitely not in set" queries */ 4915 if (((bloom_word >> h1) & (bloom_word >> h2) & 1) == 0) 4916 return (ESRCH); 4917 4918 /* Locate hash chain and corresponding value element*/ 4919 bucket = obj->buckets_gnu[req->hash_gnu % obj->nbuckets_gnu]; 4920 if (bucket == 0) 4921 return (ESRCH); 4922 hashval = &obj->chain_zero_gnu[bucket]; 4923 do { 4924 if (((*hashval ^ req->hash_gnu) >> 1) == 0) { 4925 symnum = hashval - obj->chain_zero_gnu; 4926 if (matched_symbol(req, obj, &matchres, symnum)) { 4927 req->sym_out = matchres.sym_out; 4928 req->defobj_out = obj; 4929 return (0); 4930 } 4931 } 4932 } while ((*hashval++ & 1) == 0); 4933 if (matchres.vcount == 1) { 4934 req->sym_out = matchres.vsymp; 4935 req->defobj_out = obj; 4936 return (0); 4937 } 4938 return (ESRCH); 4939 } 4940 4941 static void 4942 trace_calc_fmts(const char **main_local, const char **fmt1, const char **fmt2) 4943 { 4944 *main_local = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_PROGNAME); 4945 if (*main_local == NULL) 4946 *main_local = ""; 4947 4948 *fmt1 = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_FMT1); 4949 if (*fmt1 == NULL) 4950 *fmt1 = "\t%o => %p (%x)\n"; 4951 4952 *fmt2 = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_FMT2); 4953 if (*fmt2 == NULL) 4954 *fmt2 = "\t%o (%x)\n"; 4955 } 4956 4957 static void 4958 trace_print_obj(Obj_Entry *obj, const char *name, const char *path, 4959 const char *main_local, const char *fmt1, const char *fmt2) 4960 { 4961 const char *fmt; 4962 int c; 4963 4964 if (fmt1 == NULL) 4965 fmt = fmt2; 4966 else 4967 /* XXX bogus */ 4968 fmt = strncmp(name, "lib", 3) == 0 ? fmt1 : fmt2; 4969 4970 while ((c = *fmt++) != '\0') { 4971 switch (c) { 4972 default: 4973 rtld_putchar(c); 4974 continue; 4975 case '\\': 4976 switch (c = *fmt) { 4977 case '\0': 4978 continue; 4979 case 'n': 4980 rtld_putchar('\n'); 4981 break; 4982 case 't': 4983 rtld_putchar('\t'); 4984 break; 4985 } 4986 break; 4987 case '%': 4988 switch (c = *fmt) { 4989 case '\0': 4990 continue; 4991 case '%': 4992 default: 4993 rtld_putchar(c); 4994 break; 4995 case 'A': 4996 rtld_putstr(main_local); 4997 break; 4998 case 'a': 4999 rtld_putstr(obj_main->path); 5000 break; 5001 case 'o': 5002 rtld_putstr(name); 5003 break; 5004 case 'p': 5005 rtld_putstr(path); 5006 break; 5007 case 'x': 5008 rtld_printf("%p", obj != NULL ? 5009 obj->mapbase : NULL); 5010 break; 5011 } 5012 break; 5013 } 5014 ++fmt; 5015 } 5016 } 5017 5018 static void 5019 trace_loaded_objects(Obj_Entry *obj, bool show_preload) 5020 { 5021 const char *fmt1, *fmt2, *main_local; 5022 const char *name, *path; 5023 bool first_spurious, list_containers; 5024 5025 trace_calc_fmts(&main_local, &fmt1, &fmt2); 5026 list_containers = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_ALL) != NULL; 5027 5028 for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 5029 Needed_Entry *needed; 5030 5031 if (obj->marker) 5032 continue; 5033 if (list_containers && obj->needed != NULL) 5034 rtld_printf("%s:\n", obj->path); 5035 for (needed = obj->needed; needed; needed = needed->next) { 5036 if (needed->obj != NULL) { 5037 if (needed->obj->traced && !list_containers) 5038 continue; 5039 needed->obj->traced = true; 5040 path = needed->obj->path; 5041 } else 5042 path = "not found"; 5043 5044 name = obj->strtab + needed->name; 5045 trace_print_obj(needed->obj, name, path, main_local, 5046 fmt1, fmt2); 5047 } 5048 } 5049 5050 if (show_preload) { 5051 if (ld_get_env_var(LD_TRACE_LOADED_OBJECTS_FMT2) == NULL) 5052 fmt2 = "\t%p (%x)\n"; 5053 first_spurious = true; 5054 5055 TAILQ_FOREACH(obj, &obj_list, next) { 5056 if (obj->marker || obj == obj_main || obj->traced) 5057 continue; 5058 5059 if (list_containers && first_spurious) { 5060 rtld_printf("[preloaded]\n"); 5061 first_spurious = false; 5062 } 5063 5064 Name_Entry *fname = STAILQ_FIRST(&obj->names); 5065 name = fname == NULL ? "<unknown>" : fname->name; 5066 trace_print_obj(obj, name, obj->path, main_local, 5067 NULL, fmt2); 5068 } 5069 } 5070 } 5071 5072 /* 5073 * Unload a dlopened object and its dependencies from memory and from 5074 * our data structures. It is assumed that the DAG rooted in the 5075 * object has already been unreferenced, and that the object has a 5076 * reference count of 0. 5077 */ 5078 static void 5079 unload_object(Obj_Entry *root, RtldLockState *lockstate) 5080 { 5081 Obj_Entry marker, *obj, *next; 5082 5083 assert(root->refcount == 0); 5084 5085 /* 5086 * Pass over the DAG removing unreferenced objects from 5087 * appropriate lists. 5088 */ 5089 unlink_object(root); 5090 5091 /* Unmap all objects that are no longer referenced. */ 5092 for (obj = TAILQ_FIRST(&obj_list); obj != NULL; obj = next) { 5093 next = TAILQ_NEXT(obj, next); 5094 if (obj->marker || obj->refcount != 0) 5095 continue; 5096 LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase, 5097 obj->mapsize, 0, obj->path); 5098 dbg("unloading \"%s\"", obj->path); 5099 /* 5100 * Unlink the object now to prevent new references from 5101 * being acquired while the bind lock is dropped in 5102 * recursive dlclose() invocations. 5103 */ 5104 TAILQ_REMOVE(&obj_list, obj, next); 5105 obj_count--; 5106 5107 if (obj->filtees_loaded) { 5108 if (next != NULL) { 5109 init_marker(&marker); 5110 TAILQ_INSERT_BEFORE(next, &marker, next); 5111 unload_filtees(obj, lockstate); 5112 next = TAILQ_NEXT(&marker, next); 5113 TAILQ_REMOVE(&obj_list, &marker, next); 5114 } else 5115 unload_filtees(obj, lockstate); 5116 } 5117 release_object(obj); 5118 } 5119 } 5120 5121 static void 5122 unlink_object(Obj_Entry *root) 5123 { 5124 Objlist_Entry *elm; 5125 5126 if (root->refcount == 0) { 5127 /* Remove the object from the RTLD_GLOBAL list. */ 5128 objlist_remove(&list_global, root); 5129 5130 /* Remove the object from all objects' DAG lists. */ 5131 STAILQ_FOREACH(elm, &root->dagmembers, link) { 5132 objlist_remove(&elm->obj->dldags, root); 5133 if (elm->obj != root) 5134 unlink_object(elm->obj); 5135 } 5136 } 5137 } 5138 5139 static void 5140 ref_dag(Obj_Entry *root) 5141 { 5142 Objlist_Entry *elm; 5143 5144 assert(root->dag_inited); 5145 STAILQ_FOREACH(elm, &root->dagmembers, link) 5146 elm->obj->refcount++; 5147 } 5148 5149 static void 5150 unref_dag(Obj_Entry *root) 5151 { 5152 Objlist_Entry *elm; 5153 5154 assert(root->dag_inited); 5155 STAILQ_FOREACH(elm, &root->dagmembers, link) 5156 elm->obj->refcount--; 5157 } 5158 5159 /* 5160 * Common code for MD __tls_get_addr(). 5161 */ 5162 static void * 5163 tls_get_addr_slow(Elf_Addr **dtvp, int index, size_t offset, bool locked) 5164 { 5165 Elf_Addr *newdtv, *dtv; 5166 RtldLockState lockstate; 5167 int to_copy; 5168 5169 dtv = *dtvp; 5170 /* Check dtv generation in case new modules have arrived */ 5171 if (dtv[0] != tls_dtv_generation) { 5172 if (!locked) 5173 wlock_acquire(rtld_bind_lock, &lockstate); 5174 newdtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 5175 to_copy = dtv[1]; 5176 if (to_copy > tls_max_index) 5177 to_copy = tls_max_index; 5178 memcpy(&newdtv[2], &dtv[2], to_copy * sizeof(Elf_Addr)); 5179 newdtv[0] = tls_dtv_generation; 5180 newdtv[1] = tls_max_index; 5181 free(dtv); 5182 if (!locked) 5183 lock_release(rtld_bind_lock, &lockstate); 5184 dtv = *dtvp = newdtv; 5185 } 5186 5187 /* Dynamically allocate module TLS if necessary */ 5188 if (dtv[index + 1] == 0) { 5189 /* Signal safe, wlock will block out signals. */ 5190 if (!locked) 5191 wlock_acquire(rtld_bind_lock, &lockstate); 5192 if (!dtv[index + 1]) 5193 dtv[index + 1] = (Elf_Addr)allocate_module_tls(index); 5194 if (!locked) 5195 lock_release(rtld_bind_lock, &lockstate); 5196 } 5197 return ((void *)(dtv[index + 1] + offset)); 5198 } 5199 5200 void * 5201 tls_get_addr_common(uintptr_t **dtvp, int index, size_t offset) 5202 { 5203 uintptr_t *dtv; 5204 5205 dtv = *dtvp; 5206 /* Check dtv generation in case new modules have arrived */ 5207 if (__predict_true(dtv[0] == tls_dtv_generation && 5208 dtv[index + 1] != 0)) 5209 return ((void *)(dtv[index + 1] + offset)); 5210 return (tls_get_addr_slow(dtvp, index, offset, false)); 5211 } 5212 5213 #ifdef TLS_VARIANT_I 5214 5215 /* 5216 * Return pointer to allocated TLS block 5217 */ 5218 static void * 5219 get_tls_block_ptr(void *tcb, size_t tcbsize) 5220 { 5221 size_t extra_size, post_size, pre_size, tls_block_size; 5222 size_t tls_init_align; 5223 5224 tls_init_align = MAX(obj_main->tlsalign, 1); 5225 5226 /* Compute fragments sizes. */ 5227 extra_size = tcbsize - TLS_TCB_SIZE; 5228 post_size = calculate_tls_post_size(tls_init_align); 5229 tls_block_size = tcbsize + post_size; 5230 pre_size = roundup2(tls_block_size, tls_init_align) - tls_block_size; 5231 5232 return ((char *)tcb - pre_size - extra_size); 5233 } 5234 5235 /* 5236 * Allocate Static TLS using the Variant I method. 5237 * 5238 * For details on the layout, see lib/libc/gen/tls.c. 5239 * 5240 * NB: rtld's tls_static_space variable includes TLS_TCB_SIZE and post_size as 5241 * it is based on tls_last_offset, and TLS offsets here are really TCB 5242 * offsets, whereas libc's tls_static_space is just the executable's static 5243 * TLS segment. 5244 */ 5245 void * 5246 allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign) 5247 { 5248 Obj_Entry *obj; 5249 char *tls_block; 5250 Elf_Addr *dtv, **tcb; 5251 Elf_Addr addr; 5252 Elf_Addr i; 5253 size_t extra_size, maxalign, post_size, pre_size, tls_block_size; 5254 size_t tls_init_align, tls_init_offset; 5255 5256 if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE) 5257 return (oldtcb); 5258 5259 assert(tcbsize >= TLS_TCB_SIZE); 5260 maxalign = MAX(tcbalign, tls_static_max_align); 5261 tls_init_align = MAX(obj_main->tlsalign, 1); 5262 5263 /* Compute fragmets sizes. */ 5264 extra_size = tcbsize - TLS_TCB_SIZE; 5265 post_size = calculate_tls_post_size(tls_init_align); 5266 tls_block_size = tcbsize + post_size; 5267 pre_size = roundup2(tls_block_size, tls_init_align) - tls_block_size; 5268 tls_block_size += pre_size + tls_static_space - TLS_TCB_SIZE - post_size; 5269 5270 /* Allocate whole TLS block */ 5271 tls_block = xmalloc_aligned(tls_block_size, maxalign, 0); 5272 tcb = (Elf_Addr **)(tls_block + pre_size + extra_size); 5273 5274 if (oldtcb != NULL) { 5275 memcpy(tls_block, get_tls_block_ptr(oldtcb, tcbsize), 5276 tls_static_space); 5277 free(get_tls_block_ptr(oldtcb, tcbsize)); 5278 5279 /* Adjust the DTV. */ 5280 dtv = tcb[0]; 5281 for (i = 0; i < dtv[1]; i++) { 5282 if (dtv[i+2] >= (Elf_Addr)oldtcb && 5283 dtv[i+2] < (Elf_Addr)oldtcb + tls_static_space) { 5284 dtv[i+2] = dtv[i+2] - (Elf_Addr)oldtcb + (Elf_Addr)tcb; 5285 } 5286 } 5287 } else { 5288 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 5289 tcb[0] = dtv; 5290 dtv[0] = tls_dtv_generation; 5291 dtv[1] = tls_max_index; 5292 5293 for (obj = globallist_curr(objs); obj != NULL; 5294 obj = globallist_next(obj)) { 5295 if (obj->tlsoffset == 0) 5296 continue; 5297 tls_init_offset = obj->tlspoffset & (obj->tlsalign - 1); 5298 addr = (Elf_Addr)tcb + obj->tlsoffset; 5299 if (tls_init_offset > 0) 5300 memset((void *)addr, 0, tls_init_offset); 5301 if (obj->tlsinitsize > 0) { 5302 memcpy((void *)(addr + tls_init_offset), obj->tlsinit, 5303 obj->tlsinitsize); 5304 } 5305 if (obj->tlssize > obj->tlsinitsize) { 5306 memset((void *)(addr + tls_init_offset + obj->tlsinitsize), 5307 0, obj->tlssize - obj->tlsinitsize - tls_init_offset); 5308 } 5309 dtv[obj->tlsindex + 1] = addr; 5310 } 5311 } 5312 5313 return (tcb); 5314 } 5315 5316 void 5317 free_tls(void *tcb, size_t tcbsize, size_t tcbalign __unused) 5318 { 5319 Elf_Addr *dtv; 5320 Elf_Addr tlsstart, tlsend; 5321 size_t post_size; 5322 size_t dtvsize, i, tls_init_align __unused; 5323 5324 assert(tcbsize >= TLS_TCB_SIZE); 5325 tls_init_align = MAX(obj_main->tlsalign, 1); 5326 5327 /* Compute fragments sizes. */ 5328 post_size = calculate_tls_post_size(tls_init_align); 5329 5330 tlsstart = (Elf_Addr)tcb + TLS_TCB_SIZE + post_size; 5331 tlsend = (Elf_Addr)tcb + tls_static_space; 5332 5333 dtv = *(Elf_Addr **)tcb; 5334 dtvsize = dtv[1]; 5335 for (i = 0; i < dtvsize; i++) { 5336 if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] >= tlsend)) { 5337 free((void*)dtv[i+2]); 5338 } 5339 } 5340 free(dtv); 5341 free(get_tls_block_ptr(tcb, tcbsize)); 5342 } 5343 5344 #endif /* TLS_VARIANT_I */ 5345 5346 #ifdef TLS_VARIANT_II 5347 5348 /* 5349 * Allocate Static TLS using the Variant II method. 5350 */ 5351 void * 5352 allocate_tls(Obj_Entry *objs, void *oldtls, size_t tcbsize, size_t tcbalign) 5353 { 5354 Obj_Entry *obj; 5355 size_t size, ralign; 5356 char *tls; 5357 Elf_Addr *dtv, *olddtv; 5358 Elf_Addr segbase, oldsegbase, addr; 5359 size_t i; 5360 5361 ralign = tcbalign; 5362 if (tls_static_max_align > ralign) 5363 ralign = tls_static_max_align; 5364 size = roundup(tls_static_space, ralign) + roundup(tcbsize, ralign); 5365 5366 assert(tcbsize >= 2*sizeof(Elf_Addr)); 5367 tls = xmalloc_aligned(size, ralign, 0 /* XXX */); 5368 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 5369 5370 segbase = (Elf_Addr)(tls + roundup(tls_static_space, ralign)); 5371 ((Elf_Addr *)segbase)[0] = segbase; 5372 ((Elf_Addr *)segbase)[1] = (Elf_Addr) dtv; 5373 5374 dtv[0] = tls_dtv_generation; 5375 dtv[1] = tls_max_index; 5376 5377 if (oldtls) { 5378 /* 5379 * Copy the static TLS block over whole. 5380 */ 5381 oldsegbase = (Elf_Addr) oldtls; 5382 memcpy((void *)(segbase - tls_static_space), 5383 (const void *)(oldsegbase - tls_static_space), 5384 tls_static_space); 5385 5386 /* 5387 * If any dynamic TLS blocks have been created tls_get_addr(), 5388 * move them over. 5389 */ 5390 olddtv = ((Elf_Addr **)oldsegbase)[1]; 5391 for (i = 0; i < olddtv[1]; i++) { 5392 if (olddtv[i + 2] < oldsegbase - size || 5393 olddtv[i + 2] > oldsegbase) { 5394 dtv[i + 2] = olddtv[i + 2]; 5395 olddtv[i + 2] = 0; 5396 } 5397 } 5398 5399 /* 5400 * We assume that this block was the one we created with 5401 * allocate_initial_tls(). 5402 */ 5403 free_tls(oldtls, 2 * sizeof(Elf_Addr), sizeof(Elf_Addr)); 5404 } else { 5405 for (obj = objs; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 5406 if (obj->marker || obj->tlsoffset == 0) 5407 continue; 5408 addr = segbase - obj->tlsoffset; 5409 memset((void *)(addr + obj->tlsinitsize), 5410 0, obj->tlssize - obj->tlsinitsize); 5411 if (obj->tlsinit) { 5412 memcpy((void *)addr, obj->tlsinit, obj->tlsinitsize); 5413 obj->static_tls_copied = true; 5414 } 5415 dtv[obj->tlsindex + 1] = addr; 5416 } 5417 } 5418 5419 return ((void *)segbase); 5420 } 5421 5422 void 5423 free_tls(void *tls, size_t tcbsize __unused, size_t tcbalign) 5424 { 5425 Elf_Addr* dtv; 5426 size_t size, ralign; 5427 int dtvsize, i; 5428 Elf_Addr tlsstart, tlsend; 5429 5430 /* 5431 * Figure out the size of the initial TLS block so that we can 5432 * find stuff which ___tls_get_addr() allocated dynamically. 5433 */ 5434 ralign = tcbalign; 5435 if (tls_static_max_align > ralign) 5436 ralign = tls_static_max_align; 5437 size = roundup(tls_static_space, ralign); 5438 5439 dtv = ((Elf_Addr **)tls)[1]; 5440 dtvsize = dtv[1]; 5441 tlsend = (Elf_Addr)tls; 5442 tlsstart = tlsend - size; 5443 for (i = 0; i < dtvsize; i++) { 5444 if (dtv[i + 2] != 0 && (dtv[i + 2] < tlsstart || 5445 dtv[i + 2] > tlsend)) { 5446 free((void *)dtv[i + 2]); 5447 } 5448 } 5449 5450 free((void *)tlsstart); 5451 free((void *)dtv); 5452 } 5453 5454 #endif /* TLS_VARIANT_II */ 5455 5456 /* 5457 * Allocate TLS block for module with given index. 5458 */ 5459 void * 5460 allocate_module_tls(int index) 5461 { 5462 Obj_Entry *obj; 5463 char *p; 5464 5465 TAILQ_FOREACH(obj, &obj_list, next) { 5466 if (obj->marker) 5467 continue; 5468 if (obj->tlsindex == index) 5469 break; 5470 } 5471 if (obj == NULL) { 5472 _rtld_error("Can't find module with TLS index %d", index); 5473 rtld_die(); 5474 } 5475 5476 if (obj->tls_static) { 5477 #ifdef TLS_VARIANT_I 5478 p = (char *)_tcb_get() + obj->tlsoffset + TLS_TCB_SIZE; 5479 #else 5480 p = (char *)_tcb_get() - obj->tlsoffset; 5481 #endif 5482 return (p); 5483 } 5484 5485 obj->tls_dynamic = true; 5486 5487 p = xmalloc_aligned(obj->tlssize, obj->tlsalign, obj->tlspoffset); 5488 memcpy(p, obj->tlsinit, obj->tlsinitsize); 5489 memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize); 5490 return (p); 5491 } 5492 5493 bool 5494 allocate_tls_offset(Obj_Entry *obj) 5495 { 5496 size_t off; 5497 5498 if (obj->tls_dynamic) 5499 return (false); 5500 5501 if (obj->tls_static) 5502 return (true); 5503 5504 if (obj->tlssize == 0) { 5505 obj->tls_static = true; 5506 return (true); 5507 } 5508 5509 if (tls_last_offset == 0) 5510 off = calculate_first_tls_offset(obj->tlssize, obj->tlsalign, 5511 obj->tlspoffset); 5512 else 5513 off = calculate_tls_offset(tls_last_offset, tls_last_size, 5514 obj->tlssize, obj->tlsalign, obj->tlspoffset); 5515 5516 obj->tlsoffset = off; 5517 #ifdef TLS_VARIANT_I 5518 off += obj->tlssize; 5519 #endif 5520 5521 /* 5522 * If we have already fixed the size of the static TLS block, we 5523 * must stay within that size. When allocating the static TLS, we 5524 * leave a small amount of space spare to be used for dynamically 5525 * loading modules which use static TLS. 5526 */ 5527 if (tls_static_space != 0) { 5528 if (off > tls_static_space) 5529 return (false); 5530 } else if (obj->tlsalign > tls_static_max_align) { 5531 tls_static_max_align = obj->tlsalign; 5532 } 5533 5534 tls_last_offset = off; 5535 tls_last_size = obj->tlssize; 5536 obj->tls_static = true; 5537 5538 return (true); 5539 } 5540 5541 void 5542 free_tls_offset(Obj_Entry *obj) 5543 { 5544 5545 /* 5546 * If we were the last thing to allocate out of the static TLS 5547 * block, we give our space back to the 'allocator'. This is a 5548 * simplistic workaround to allow libGL.so.1 to be loaded and 5549 * unloaded multiple times. 5550 */ 5551 size_t off = obj->tlsoffset; 5552 #ifdef TLS_VARIANT_I 5553 off += obj->tlssize; 5554 #endif 5555 if (off == tls_last_offset) { 5556 tls_last_offset -= obj->tlssize; 5557 tls_last_size = 0; 5558 } 5559 } 5560 5561 void * 5562 _rtld_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign) 5563 { 5564 void *ret; 5565 RtldLockState lockstate; 5566 5567 wlock_acquire(rtld_bind_lock, &lockstate); 5568 ret = allocate_tls(globallist_curr(TAILQ_FIRST(&obj_list)), oldtls, 5569 tcbsize, tcbalign); 5570 lock_release(rtld_bind_lock, &lockstate); 5571 return (ret); 5572 } 5573 5574 void 5575 _rtld_free_tls(void *tcb, size_t tcbsize, size_t tcbalign) 5576 { 5577 RtldLockState lockstate; 5578 5579 wlock_acquire(rtld_bind_lock, &lockstate); 5580 free_tls(tcb, tcbsize, tcbalign); 5581 lock_release(rtld_bind_lock, &lockstate); 5582 } 5583 5584 static void 5585 object_add_name(Obj_Entry *obj, const char *name) 5586 { 5587 Name_Entry *entry; 5588 size_t len; 5589 5590 len = strlen(name); 5591 entry = malloc(sizeof(Name_Entry) + len); 5592 5593 if (entry != NULL) { 5594 strcpy(entry->name, name); 5595 STAILQ_INSERT_TAIL(&obj->names, entry, link); 5596 } 5597 } 5598 5599 static int 5600 object_match_name(const Obj_Entry *obj, const char *name) 5601 { 5602 Name_Entry *entry; 5603 5604 STAILQ_FOREACH(entry, &obj->names, link) { 5605 if (strcmp(name, entry->name) == 0) 5606 return (1); 5607 } 5608 return (0); 5609 } 5610 5611 static Obj_Entry * 5612 locate_dependency(const Obj_Entry *obj, const char *name) 5613 { 5614 const Objlist_Entry *entry; 5615 const Needed_Entry *needed; 5616 5617 STAILQ_FOREACH(entry, &list_main, link) { 5618 if (object_match_name(entry->obj, name)) 5619 return (entry->obj); 5620 } 5621 5622 for (needed = obj->needed; needed != NULL; needed = needed->next) { 5623 if (strcmp(obj->strtab + needed->name, name) == 0 || 5624 (needed->obj != NULL && object_match_name(needed->obj, name))) { 5625 /* 5626 * If there is DT_NEEDED for the name we are looking for, 5627 * we are all set. Note that object might not be found if 5628 * dependency was not loaded yet, so the function can 5629 * return NULL here. This is expected and handled 5630 * properly by the caller. 5631 */ 5632 return (needed->obj); 5633 } 5634 } 5635 _rtld_error("%s: Unexpected inconsistency: dependency %s not found", 5636 obj->path, name); 5637 rtld_die(); 5638 } 5639 5640 static int 5641 check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj, 5642 const Elf_Vernaux *vna) 5643 { 5644 const Elf_Verdef *vd; 5645 const char *vername; 5646 5647 vername = refobj->strtab + vna->vna_name; 5648 vd = depobj->verdef; 5649 if (vd == NULL) { 5650 _rtld_error("%s: version %s required by %s not defined", 5651 depobj->path, vername, refobj->path); 5652 return (-1); 5653 } 5654 for (;;) { 5655 if (vd->vd_version != VER_DEF_CURRENT) { 5656 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 5657 depobj->path, vd->vd_version); 5658 return (-1); 5659 } 5660 if (vna->vna_hash == vd->vd_hash) { 5661 const Elf_Verdaux *aux = (const Elf_Verdaux *) 5662 ((const char *)vd + vd->vd_aux); 5663 if (strcmp(vername, depobj->strtab + aux->vda_name) == 0) 5664 return (0); 5665 } 5666 if (vd->vd_next == 0) 5667 break; 5668 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 5669 } 5670 if (vna->vna_flags & VER_FLG_WEAK) 5671 return (0); 5672 _rtld_error("%s: version %s required by %s not found", 5673 depobj->path, vername, refobj->path); 5674 return (-1); 5675 } 5676 5677 static int 5678 rtld_verify_object_versions(Obj_Entry *obj) 5679 { 5680 const Elf_Verneed *vn; 5681 const Elf_Verdef *vd; 5682 const Elf_Verdaux *vda; 5683 const Elf_Vernaux *vna; 5684 const Obj_Entry *depobj; 5685 int maxvernum, vernum; 5686 5687 if (obj->ver_checked) 5688 return (0); 5689 obj->ver_checked = true; 5690 5691 maxvernum = 0; 5692 /* 5693 * Walk over defined and required version records and figure out 5694 * max index used by any of them. Do very basic sanity checking 5695 * while there. 5696 */ 5697 vn = obj->verneed; 5698 while (vn != NULL) { 5699 if (vn->vn_version != VER_NEED_CURRENT) { 5700 _rtld_error("%s: Unsupported version %d of Elf_Verneed entry", 5701 obj->path, vn->vn_version); 5702 return (-1); 5703 } 5704 vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux); 5705 for (;;) { 5706 vernum = VER_NEED_IDX(vna->vna_other); 5707 if (vernum > maxvernum) 5708 maxvernum = vernum; 5709 if (vna->vna_next == 0) 5710 break; 5711 vna = (const Elf_Vernaux *)((const char *)vna + vna->vna_next); 5712 } 5713 if (vn->vn_next == 0) 5714 break; 5715 vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next); 5716 } 5717 5718 vd = obj->verdef; 5719 while (vd != NULL) { 5720 if (vd->vd_version != VER_DEF_CURRENT) { 5721 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 5722 obj->path, vd->vd_version); 5723 return (-1); 5724 } 5725 vernum = VER_DEF_IDX(vd->vd_ndx); 5726 if (vernum > maxvernum) 5727 maxvernum = vernum; 5728 if (vd->vd_next == 0) 5729 break; 5730 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 5731 } 5732 5733 if (maxvernum == 0) 5734 return (0); 5735 5736 /* 5737 * Store version information in array indexable by version index. 5738 * Verify that object version requirements are satisfied along the 5739 * way. 5740 */ 5741 obj->vernum = maxvernum + 1; 5742 obj->vertab = xcalloc(obj->vernum, sizeof(Ver_Entry)); 5743 5744 vd = obj->verdef; 5745 while (vd != NULL) { 5746 if ((vd->vd_flags & VER_FLG_BASE) == 0) { 5747 vernum = VER_DEF_IDX(vd->vd_ndx); 5748 assert(vernum <= maxvernum); 5749 vda = (const Elf_Verdaux *)((const char *)vd + vd->vd_aux); 5750 obj->vertab[vernum].hash = vd->vd_hash; 5751 obj->vertab[vernum].name = obj->strtab + vda->vda_name; 5752 obj->vertab[vernum].file = NULL; 5753 obj->vertab[vernum].flags = 0; 5754 } 5755 if (vd->vd_next == 0) 5756 break; 5757 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 5758 } 5759 5760 vn = obj->verneed; 5761 while (vn != NULL) { 5762 depobj = locate_dependency(obj, obj->strtab + vn->vn_file); 5763 if (depobj == NULL) 5764 return (-1); 5765 vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux); 5766 for (;;) { 5767 if (check_object_provided_version(obj, depobj, vna)) 5768 return (-1); 5769 vernum = VER_NEED_IDX(vna->vna_other); 5770 assert(vernum <= maxvernum); 5771 obj->vertab[vernum].hash = vna->vna_hash; 5772 obj->vertab[vernum].name = obj->strtab + vna->vna_name; 5773 obj->vertab[vernum].file = obj->strtab + vn->vn_file; 5774 obj->vertab[vernum].flags = (vna->vna_other & VER_NEED_HIDDEN) ? 5775 VER_INFO_HIDDEN : 0; 5776 if (vna->vna_next == 0) 5777 break; 5778 vna = (const Elf_Vernaux *)((const char *)vna + vna->vna_next); 5779 } 5780 if (vn->vn_next == 0) 5781 break; 5782 vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next); 5783 } 5784 return (0); 5785 } 5786 5787 static int 5788 rtld_verify_versions(const Objlist *objlist) 5789 { 5790 Objlist_Entry *entry; 5791 int rc; 5792 5793 rc = 0; 5794 STAILQ_FOREACH(entry, objlist, link) { 5795 /* 5796 * Skip dummy objects or objects that have their version requirements 5797 * already checked. 5798 */ 5799 if (entry->obj->strtab == NULL || entry->obj->vertab != NULL) 5800 continue; 5801 if (rtld_verify_object_versions(entry->obj) == -1) { 5802 rc = -1; 5803 if (ld_tracing == NULL) 5804 break; 5805 } 5806 } 5807 if (rc == 0 || ld_tracing != NULL) 5808 rc = rtld_verify_object_versions(&obj_rtld); 5809 return (rc); 5810 } 5811 5812 const Ver_Entry * 5813 fetch_ventry(const Obj_Entry *obj, unsigned long symnum) 5814 { 5815 Elf_Versym vernum; 5816 5817 if (obj->vertab) { 5818 vernum = VER_NDX(obj->versyms[symnum]); 5819 if (vernum >= obj->vernum) { 5820 _rtld_error("%s: symbol %s has wrong verneed value %d", 5821 obj->path, obj->strtab + symnum, vernum); 5822 } else if (obj->vertab[vernum].hash != 0) { 5823 return (&obj->vertab[vernum]); 5824 } 5825 } 5826 return (NULL); 5827 } 5828 5829 int 5830 _rtld_get_stack_prot(void) 5831 { 5832 5833 return (stack_prot); 5834 } 5835 5836 int 5837 _rtld_is_dlopened(void *arg) 5838 { 5839 Obj_Entry *obj; 5840 RtldLockState lockstate; 5841 int res; 5842 5843 rlock_acquire(rtld_bind_lock, &lockstate); 5844 obj = dlcheck(arg); 5845 if (obj == NULL) 5846 obj = obj_from_addr(arg); 5847 if (obj == NULL) { 5848 _rtld_error("No shared object contains address"); 5849 lock_release(rtld_bind_lock, &lockstate); 5850 return (-1); 5851 } 5852 res = obj->dlopened ? 1 : 0; 5853 lock_release(rtld_bind_lock, &lockstate); 5854 return (res); 5855 } 5856 5857 static int 5858 obj_remap_relro(Obj_Entry *obj, int prot) 5859 { 5860 5861 if (obj->relro_size > 0 && mprotect(obj->relro_page, obj->relro_size, 5862 prot) == -1) { 5863 _rtld_error("%s: Cannot set relro protection to %#x: %s", 5864 obj->path, prot, rtld_strerror(errno)); 5865 return (-1); 5866 } 5867 return (0); 5868 } 5869 5870 static int 5871 obj_disable_relro(Obj_Entry *obj) 5872 { 5873 5874 return (obj_remap_relro(obj, PROT_READ | PROT_WRITE)); 5875 } 5876 5877 static int 5878 obj_enforce_relro(Obj_Entry *obj) 5879 { 5880 5881 return (obj_remap_relro(obj, PROT_READ)); 5882 } 5883 5884 static void 5885 map_stacks_exec(RtldLockState *lockstate) 5886 { 5887 void (*thr_map_stacks_exec)(void); 5888 5889 if ((max_stack_flags & PF_X) == 0 || (stack_prot & PROT_EXEC) != 0) 5890 return; 5891 thr_map_stacks_exec = (void (*)(void))(uintptr_t) 5892 get_program_var_addr("__pthread_map_stacks_exec", lockstate); 5893 if (thr_map_stacks_exec != NULL) { 5894 stack_prot |= PROT_EXEC; 5895 thr_map_stacks_exec(); 5896 } 5897 } 5898 5899 static void 5900 distribute_static_tls(Objlist *list, RtldLockState *lockstate) 5901 { 5902 Objlist_Entry *elm; 5903 Obj_Entry *obj; 5904 void (*distrib)(size_t, void *, size_t, size_t); 5905 5906 distrib = (void (*)(size_t, void *, size_t, size_t))(uintptr_t) 5907 get_program_var_addr("__pthread_distribute_static_tls", lockstate); 5908 if (distrib == NULL) 5909 return; 5910 STAILQ_FOREACH(elm, list, link) { 5911 obj = elm->obj; 5912 if (obj->marker || !obj->tls_static || obj->static_tls_copied) 5913 continue; 5914 lock_release(rtld_bind_lock, lockstate); 5915 distrib(obj->tlsoffset, obj->tlsinit, obj->tlsinitsize, 5916 obj->tlssize); 5917 wlock_acquire(rtld_bind_lock, lockstate); 5918 obj->static_tls_copied = true; 5919 } 5920 } 5921 5922 void 5923 symlook_init(SymLook *dst, const char *name) 5924 { 5925 5926 bzero(dst, sizeof(*dst)); 5927 dst->name = name; 5928 dst->hash = elf_hash(name); 5929 dst->hash_gnu = gnu_hash(name); 5930 } 5931 5932 static void 5933 symlook_init_from_req(SymLook *dst, const SymLook *src) 5934 { 5935 5936 dst->name = src->name; 5937 dst->hash = src->hash; 5938 dst->hash_gnu = src->hash_gnu; 5939 dst->ventry = src->ventry; 5940 dst->flags = src->flags; 5941 dst->defobj_out = NULL; 5942 dst->sym_out = NULL; 5943 dst->lockstate = src->lockstate; 5944 } 5945 5946 static int 5947 open_binary_fd(const char *argv0, bool search_in_path, 5948 const char **binpath_res) 5949 { 5950 char *binpath, *pathenv, *pe, *res1; 5951 const char *res; 5952 int fd; 5953 5954 binpath = NULL; 5955 res = NULL; 5956 if (search_in_path && strchr(argv0, '/') == NULL) { 5957 binpath = xmalloc(PATH_MAX); 5958 pathenv = getenv("PATH"); 5959 if (pathenv == NULL) { 5960 _rtld_error("-p and no PATH environment variable"); 5961 rtld_die(); 5962 } 5963 pathenv = strdup(pathenv); 5964 if (pathenv == NULL) { 5965 _rtld_error("Cannot allocate memory"); 5966 rtld_die(); 5967 } 5968 fd = -1; 5969 errno = ENOENT; 5970 while ((pe = strsep(&pathenv, ":")) != NULL) { 5971 if (strlcpy(binpath, pe, PATH_MAX) >= PATH_MAX) 5972 continue; 5973 if (binpath[0] != '\0' && 5974 strlcat(binpath, "/", PATH_MAX) >= PATH_MAX) 5975 continue; 5976 if (strlcat(binpath, argv0, PATH_MAX) >= PATH_MAX) 5977 continue; 5978 fd = open(binpath, O_RDONLY | O_CLOEXEC | O_VERIFY); 5979 if (fd != -1 || errno != ENOENT) { 5980 res = binpath; 5981 break; 5982 } 5983 } 5984 free(pathenv); 5985 } else { 5986 fd = open(argv0, O_RDONLY | O_CLOEXEC | O_VERIFY); 5987 res = argv0; 5988 } 5989 5990 if (fd == -1) { 5991 _rtld_error("Cannot open %s: %s", argv0, rtld_strerror(errno)); 5992 rtld_die(); 5993 } 5994 if (res != NULL && res[0] != '/') { 5995 res1 = xmalloc(PATH_MAX); 5996 if (realpath(res, res1) != NULL) { 5997 if (res != argv0) 5998 free(__DECONST(char *, res)); 5999 res = res1; 6000 } else { 6001 free(res1); 6002 } 6003 } 6004 *binpath_res = res; 6005 return (fd); 6006 } 6007 6008 /* 6009 * Parse a set of command-line arguments. 6010 */ 6011 static int 6012 parse_args(char* argv[], int argc, bool *use_pathp, int *fdp, 6013 const char **argv0, bool *dir_ignore) 6014 { 6015 const char *arg; 6016 char machine[64]; 6017 size_t sz; 6018 int arglen, fd, i, j, mib[2]; 6019 char opt; 6020 bool seen_b, seen_f; 6021 6022 dbg("Parsing command-line arguments"); 6023 *use_pathp = false; 6024 *fdp = -1; 6025 *dir_ignore = false; 6026 seen_b = seen_f = false; 6027 6028 for (i = 1; i < argc; i++ ) { 6029 arg = argv[i]; 6030 dbg("argv[%d]: '%s'", i, arg); 6031 6032 /* 6033 * rtld arguments end with an explicit "--" or with the first 6034 * non-prefixed argument. 6035 */ 6036 if (strcmp(arg, "--") == 0) { 6037 i++; 6038 break; 6039 } 6040 if (arg[0] != '-') 6041 break; 6042 6043 /* 6044 * All other arguments are single-character options that can 6045 * be combined, so we need to search through `arg` for them. 6046 */ 6047 arglen = strlen(arg); 6048 for (j = 1; j < arglen; j++) { 6049 opt = arg[j]; 6050 if (opt == 'h') { 6051 print_usage(argv[0]); 6052 _exit(0); 6053 } else if (opt == 'b') { 6054 if (seen_f) { 6055 _rtld_error("Both -b and -f specified"); 6056 rtld_die(); 6057 } 6058 if (j != arglen - 1) { 6059 _rtld_error("Invalid options: %s", arg); 6060 rtld_die(); 6061 } 6062 i++; 6063 *argv0 = argv[i]; 6064 seen_b = true; 6065 break; 6066 } else if (opt == 'd') { 6067 *dir_ignore = true; 6068 } else if (opt == 'f') { 6069 if (seen_b) { 6070 _rtld_error("Both -b and -f specified"); 6071 rtld_die(); 6072 } 6073 6074 /* 6075 * -f XX can be used to specify a 6076 * descriptor for the binary named at 6077 * the command line (i.e., the later 6078 * argument will specify the process 6079 * name but the descriptor is what 6080 * will actually be executed). 6081 * 6082 * -f must be the last option in the 6083 * group, e.g., -abcf <fd>. 6084 */ 6085 if (j != arglen - 1) { 6086 _rtld_error("Invalid options: %s", arg); 6087 rtld_die(); 6088 } 6089 i++; 6090 fd = parse_integer(argv[i]); 6091 if (fd == -1) { 6092 _rtld_error( 6093 "Invalid file descriptor: '%s'", 6094 argv[i]); 6095 rtld_die(); 6096 } 6097 *fdp = fd; 6098 seen_f = true; 6099 break; 6100 } else if (opt == 'p') { 6101 *use_pathp = true; 6102 } else if (opt == 'u') { 6103 trust = false; 6104 } else if (opt == 'v') { 6105 machine[0] = '\0'; 6106 mib[0] = CTL_HW; 6107 mib[1] = HW_MACHINE; 6108 sz = sizeof(machine); 6109 sysctl(mib, nitems(mib), machine, &sz, NULL, 0); 6110 ld_elf_hints_path = ld_get_env_var( 6111 LD_ELF_HINTS_PATH); 6112 set_ld_elf_hints_path(); 6113 rtld_printf( 6114 "FreeBSD ld-elf.so.1 %s\n" 6115 "FreeBSD_version %d\n" 6116 "Default lib path %s\n" 6117 "Hints lib path %s\n" 6118 "Env prefix %s\n" 6119 "Default hint file %s\n" 6120 "Hint file %s\n" 6121 "libmap file %s\n", 6122 machine, 6123 __FreeBSD_version, ld_standard_library_path, 6124 gethints(false), 6125 ld_env_prefix, ld_elf_hints_default, 6126 ld_elf_hints_path, 6127 ld_path_libmap_conf); 6128 _exit(0); 6129 } else { 6130 _rtld_error("Invalid argument: '%s'", arg); 6131 print_usage(argv[0]); 6132 rtld_die(); 6133 } 6134 } 6135 } 6136 6137 if (!seen_b) 6138 *argv0 = argv[i]; 6139 return (i); 6140 } 6141 6142 /* 6143 * Parse a file descriptor number without pulling in more of libc (e.g. atoi). 6144 */ 6145 static int 6146 parse_integer(const char *str) 6147 { 6148 static const int RADIX = 10; /* XXXJA: possibly support hex? */ 6149 const char *orig; 6150 int n; 6151 char c; 6152 6153 orig = str; 6154 n = 0; 6155 for (c = *str; c != '\0'; c = *++str) { 6156 if (c < '0' || c > '9') 6157 return (-1); 6158 6159 n *= RADIX; 6160 n += c - '0'; 6161 } 6162 6163 /* Make sure we actually parsed something. */ 6164 if (str == orig) 6165 return (-1); 6166 return (n); 6167 } 6168 6169 static void 6170 print_usage(const char *argv0) 6171 { 6172 6173 rtld_printf( 6174 "Usage: %s [-h] [-b <exe>] [-d] [-f <FD>] [-p] [--] <binary> [<args>]\n" 6175 "\n" 6176 "Options:\n" 6177 " -h Display this help message\n" 6178 " -b <exe> Execute <exe> instead of <binary>, arg0 is <binary>\n" 6179 " -d Ignore lack of exec permissions for the binary\n" 6180 " -f <FD> Execute <FD> instead of searching for <binary>\n" 6181 " -p Search in PATH for named binary\n" 6182 " -u Ignore LD_ environment variables\n" 6183 " -v Display identification information\n" 6184 " -- End of RTLD options\n" 6185 " <binary> Name of process to execute\n" 6186 " <args> Arguments to the executed process\n", argv0); 6187 } 6188 6189 #define AUXFMT(at, xfmt) [at] = { .name = #at, .fmt = xfmt } 6190 static const struct auxfmt { 6191 const char *name; 6192 const char *fmt; 6193 } auxfmts[] = { 6194 AUXFMT(AT_NULL, NULL), 6195 AUXFMT(AT_IGNORE, NULL), 6196 AUXFMT(AT_EXECFD, "%ld"), 6197 AUXFMT(AT_PHDR, "%p"), 6198 AUXFMT(AT_PHENT, "%lu"), 6199 AUXFMT(AT_PHNUM, "%lu"), 6200 AUXFMT(AT_PAGESZ, "%lu"), 6201 AUXFMT(AT_BASE, "%#lx"), 6202 AUXFMT(AT_FLAGS, "%#lx"), 6203 AUXFMT(AT_ENTRY, "%p"), 6204 AUXFMT(AT_NOTELF, NULL), 6205 AUXFMT(AT_UID, "%ld"), 6206 AUXFMT(AT_EUID, "%ld"), 6207 AUXFMT(AT_GID, "%ld"), 6208 AUXFMT(AT_EGID, "%ld"), 6209 AUXFMT(AT_EXECPATH, "%s"), 6210 AUXFMT(AT_CANARY, "%p"), 6211 AUXFMT(AT_CANARYLEN, "%lu"), 6212 AUXFMT(AT_OSRELDATE, "%lu"), 6213 AUXFMT(AT_NCPUS, "%lu"), 6214 AUXFMT(AT_PAGESIZES, "%p"), 6215 AUXFMT(AT_PAGESIZESLEN, "%lu"), 6216 AUXFMT(AT_TIMEKEEP, "%p"), 6217 AUXFMT(AT_STACKPROT, "%#lx"), 6218 AUXFMT(AT_EHDRFLAGS, "%#lx"), 6219 AUXFMT(AT_HWCAP, "%#lx"), 6220 AUXFMT(AT_HWCAP2, "%#lx"), 6221 AUXFMT(AT_BSDFLAGS, "%#lx"), 6222 AUXFMT(AT_ARGC, "%lu"), 6223 AUXFMT(AT_ARGV, "%p"), 6224 AUXFMT(AT_ENVC, "%p"), 6225 AUXFMT(AT_ENVV, "%p"), 6226 AUXFMT(AT_PS_STRINGS, "%p"), 6227 AUXFMT(AT_FXRNG, "%p"), 6228 AUXFMT(AT_KPRELOAD, "%p"), 6229 AUXFMT(AT_USRSTACKBASE, "%#lx"), 6230 AUXFMT(AT_USRSTACKLIM, "%#lx"), 6231 }; 6232 6233 static bool 6234 is_ptr_fmt(const char *fmt) 6235 { 6236 char last; 6237 6238 last = fmt[strlen(fmt) - 1]; 6239 return (last == 'p' || last == 's'); 6240 } 6241 6242 static void 6243 dump_auxv(Elf_Auxinfo **aux_info) 6244 { 6245 Elf_Auxinfo *auxp; 6246 const struct auxfmt *fmt; 6247 int i; 6248 6249 for (i = 0; i < AT_COUNT; i++) { 6250 auxp = aux_info[i]; 6251 if (auxp == NULL) 6252 continue; 6253 fmt = &auxfmts[i]; 6254 if (fmt->fmt == NULL) 6255 continue; 6256 rtld_fdprintf(STDOUT_FILENO, "%s:\t", fmt->name); 6257 if (is_ptr_fmt(fmt->fmt)) { 6258 rtld_fdprintfx(STDOUT_FILENO, fmt->fmt, 6259 auxp->a_un.a_ptr); 6260 } else { 6261 rtld_fdprintfx(STDOUT_FILENO, fmt->fmt, 6262 auxp->a_un.a_val); 6263 } 6264 rtld_fdprintf(STDOUT_FILENO, "\n"); 6265 } 6266 } 6267 6268 /* 6269 * Overrides for libc_pic-provided functions. 6270 */ 6271 6272 int 6273 __getosreldate(void) 6274 { 6275 size_t len; 6276 int oid[2]; 6277 int error, osrel; 6278 6279 if (osreldate != 0) 6280 return (osreldate); 6281 6282 oid[0] = CTL_KERN; 6283 oid[1] = KERN_OSRELDATE; 6284 osrel = 0; 6285 len = sizeof(osrel); 6286 error = sysctl(oid, 2, &osrel, &len, NULL, 0); 6287 if (error == 0 && osrel > 0 && len == sizeof(osrel)) 6288 osreldate = osrel; 6289 return (osreldate); 6290 } 6291 const char * 6292 rtld_strerror(int errnum) 6293 { 6294 6295 if (errnum < 0 || errnum >= sys_nerr) 6296 return ("Unknown error"); 6297 return (sys_errlist[errnum]); 6298 } 6299 6300 char * 6301 getenv(const char *name) 6302 { 6303 return (__DECONST(char *, rtld_get_env_val(environ, name, 6304 strlen(name)))); 6305 } 6306 6307 /* malloc */ 6308 void * 6309 malloc(size_t nbytes) 6310 { 6311 6312 return (__crt_malloc(nbytes)); 6313 } 6314 6315 void * 6316 calloc(size_t num, size_t size) 6317 { 6318 6319 return (__crt_calloc(num, size)); 6320 } 6321 6322 void 6323 free(void *cp) 6324 { 6325 6326 __crt_free(cp); 6327 } 6328 6329 void * 6330 realloc(void *cp, size_t nbytes) 6331 { 6332 6333 return (__crt_realloc(cp, nbytes)); 6334 } 6335 6336 extern int _rtld_version__FreeBSD_version __exported; 6337 int _rtld_version__FreeBSD_version = __FreeBSD_version; 6338 6339 extern char _rtld_version_laddr_offset __exported; 6340 char _rtld_version_laddr_offset; 6341 6342 extern char _rtld_version_dlpi_tls_data __exported; 6343 char _rtld_version_dlpi_tls_data; 6344