1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright 1996, 1997, 1998, 1999, 2000 John D. Polstra. 5 * Copyright 2003 Alexander Kabaev <kan@FreeBSD.ORG>. 6 * Copyright 2009-2013 Konstantin Belousov <kib@FreeBSD.ORG>. 7 * Copyright 2012 John Marino <draco@marino.st>. 8 * Copyright 2014-2017 The FreeBSD Foundation 9 * All rights reserved. 10 * 11 * Portions of this software were developed by Konstantin Belousov 12 * under sponsorship from the FreeBSD Foundation. 13 * 14 * Redistribution and use in source and binary forms, with or without 15 * modification, are permitted provided that the following conditions 16 * are met: 17 * 1. Redistributions of source code must retain the above copyright 18 * notice, this list of conditions and the following disclaimer. 19 * 2. Redistributions in binary form must reproduce the above copyright 20 * notice, this list of conditions and the following disclaimer in the 21 * documentation and/or other materials provided with the distribution. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 24 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 25 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 26 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 27 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 28 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 29 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 30 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 31 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 32 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 33 */ 34 35 /* 36 * Dynamic linker for ELF. 37 * 38 * John Polstra <jdp@polstra.com>. 39 */ 40 41 #include <sys/cdefs.h> 42 __FBSDID("$FreeBSD$"); 43 44 #include <sys/param.h> 45 #include <sys/mount.h> 46 #include <sys/mman.h> 47 #include <sys/stat.h> 48 #include <sys/sysctl.h> 49 #include <sys/uio.h> 50 #include <sys/utsname.h> 51 #include <sys/ktrace.h> 52 53 #include <dlfcn.h> 54 #include <err.h> 55 #include <errno.h> 56 #include <fcntl.h> 57 #include <stdarg.h> 58 #include <stdio.h> 59 #include <stdlib.h> 60 #include <string.h> 61 #include <unistd.h> 62 63 #include "debug.h" 64 #include "rtld.h" 65 #include "libmap.h" 66 #include "rtld_paths.h" 67 #include "rtld_tls.h" 68 #include "rtld_printf.h" 69 #include "rtld_malloc.h" 70 #include "rtld_utrace.h" 71 #include "notes.h" 72 #include "rtld_libc.h" 73 74 /* Types. */ 75 typedef void (*func_ptr_type)(void); 76 typedef void * (*path_enum_proc) (const char *path, size_t len, void *arg); 77 78 79 /* Variables that cannot be static: */ 80 extern struct r_debug r_debug; /* For GDB */ 81 extern int _thread_autoinit_dummy_decl; 82 extern void (*__cleanup)(void); 83 84 struct dlerror_save { 85 int seen; 86 char *msg; 87 }; 88 89 /* 90 * Function declarations. 91 */ 92 static const char *basename(const char *); 93 static void digest_dynamic1(Obj_Entry *, int, const Elf_Dyn **, 94 const Elf_Dyn **, const Elf_Dyn **); 95 static bool digest_dynamic2(Obj_Entry *, const Elf_Dyn *, const Elf_Dyn *, 96 const Elf_Dyn *); 97 static bool digest_dynamic(Obj_Entry *, int); 98 static Obj_Entry *digest_phdr(const Elf_Phdr *, int, caddr_t, const char *); 99 static void distribute_static_tls(Objlist *, RtldLockState *); 100 static Obj_Entry *dlcheck(void *); 101 static int dlclose_locked(void *, RtldLockState *); 102 static Obj_Entry *dlopen_object(const char *name, int fd, Obj_Entry *refobj, 103 int lo_flags, int mode, RtldLockState *lockstate); 104 static Obj_Entry *do_load_object(int, const char *, char *, struct stat *, int); 105 static int do_search_info(const Obj_Entry *obj, int, struct dl_serinfo *); 106 static bool donelist_check(DoneList *, const Obj_Entry *); 107 static void dump_auxv(Elf_Auxinfo **aux_info); 108 static void errmsg_restore(struct dlerror_save *); 109 static struct dlerror_save *errmsg_save(void); 110 static void *fill_search_info(const char *, size_t, void *); 111 static char *find_library(const char *, const Obj_Entry *, int *); 112 static const char *gethints(bool); 113 static void hold_object(Obj_Entry *); 114 static void unhold_object(Obj_Entry *); 115 static void init_dag(Obj_Entry *); 116 static void init_marker(Obj_Entry *); 117 static void init_pagesizes(Elf_Auxinfo **aux_info); 118 static void init_rtld(caddr_t, Elf_Auxinfo **); 119 static void initlist_add_neededs(Needed_Entry *, Objlist *); 120 static void initlist_add_objects(Obj_Entry *, Obj_Entry *, Objlist *); 121 static int initlist_objects_ifunc(Objlist *, bool, int, RtldLockState *); 122 static void linkmap_add(Obj_Entry *); 123 static void linkmap_delete(Obj_Entry *); 124 static void load_filtees(Obj_Entry *, int flags, RtldLockState *); 125 static void unload_filtees(Obj_Entry *, RtldLockState *); 126 static int load_needed_objects(Obj_Entry *, int); 127 static int load_preload_objects(const char *, bool); 128 static int load_kpreload(const void *addr); 129 static Obj_Entry *load_object(const char *, int fd, const Obj_Entry *, int); 130 static void map_stacks_exec(RtldLockState *); 131 static int obj_disable_relro(Obj_Entry *); 132 static int obj_enforce_relro(Obj_Entry *); 133 static void objlist_call_fini(Objlist *, Obj_Entry *, RtldLockState *); 134 static void objlist_call_init(Objlist *, RtldLockState *); 135 static void objlist_clear(Objlist *); 136 static Objlist_Entry *objlist_find(Objlist *, const Obj_Entry *); 137 static void objlist_init(Objlist *); 138 static void objlist_push_head(Objlist *, Obj_Entry *); 139 static void objlist_push_tail(Objlist *, Obj_Entry *); 140 static void objlist_put_after(Objlist *, Obj_Entry *, Obj_Entry *); 141 static void objlist_remove(Objlist *, Obj_Entry *); 142 static int open_binary_fd(const char *argv0, bool search_in_path, 143 const char **binpath_res); 144 static int parse_args(char* argv[], int argc, bool *use_pathp, int *fdp, 145 const char **argv0, bool *dir_ignore); 146 static int parse_integer(const char *); 147 static void *path_enumerate(const char *, path_enum_proc, const char *, void *); 148 static void print_usage(const char *argv0); 149 static void release_object(Obj_Entry *); 150 static int relocate_object_dag(Obj_Entry *root, bool bind_now, 151 Obj_Entry *rtldobj, int flags, RtldLockState *lockstate); 152 static int relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, 153 int flags, RtldLockState *lockstate); 154 static int relocate_objects(Obj_Entry *, bool, Obj_Entry *, int, 155 RtldLockState *); 156 static int resolve_object_ifunc(Obj_Entry *, bool, int, RtldLockState *); 157 static int rtld_dirname(const char *, char *); 158 static int rtld_dirname_abs(const char *, char *); 159 static void *rtld_dlopen(const char *name, int fd, int mode); 160 static void rtld_exit(void); 161 static void rtld_nop_exit(void); 162 static char *search_library_path(const char *, const char *, const char *, 163 int *); 164 static char *search_library_pathfds(const char *, const char *, int *); 165 static const void **get_program_var_addr(const char *, RtldLockState *); 166 static void set_program_var(const char *, const void *); 167 static int symlook_default(SymLook *, const Obj_Entry *refobj); 168 static int symlook_global(SymLook *, DoneList *); 169 static void symlook_init_from_req(SymLook *, const SymLook *); 170 static int symlook_list(SymLook *, const Objlist *, DoneList *); 171 static int symlook_needed(SymLook *, const Needed_Entry *, DoneList *); 172 static int symlook_obj1_sysv(SymLook *, const Obj_Entry *); 173 static int symlook_obj1_gnu(SymLook *, const Obj_Entry *); 174 static void *tls_get_addr_slow(Elf_Addr **, int, size_t, bool) __noinline; 175 static void trace_loaded_objects(Obj_Entry *, bool); 176 static void unlink_object(Obj_Entry *); 177 static void unload_object(Obj_Entry *, RtldLockState *lockstate); 178 static void unref_dag(Obj_Entry *); 179 static void ref_dag(Obj_Entry *); 180 static char *origin_subst_one(Obj_Entry *, char *, const char *, 181 const char *, bool); 182 static char *origin_subst(Obj_Entry *, const char *); 183 static bool obj_resolve_origin(Obj_Entry *obj); 184 static void preinit_main(void); 185 static int rtld_verify_versions(const Objlist *); 186 static int rtld_verify_object_versions(Obj_Entry *); 187 static void object_add_name(Obj_Entry *, const char *); 188 static int object_match_name(const Obj_Entry *, const char *); 189 static void ld_utrace_log(int, void *, void *, size_t, int, const char *); 190 static void rtld_fill_dl_phdr_info(const Obj_Entry *obj, 191 struct dl_phdr_info *phdr_info); 192 static uint32_t gnu_hash(const char *); 193 static bool matched_symbol(SymLook *, const Obj_Entry *, Sym_Match_Result *, 194 const unsigned long); 195 196 void r_debug_state(struct r_debug *, struct link_map *) __noinline __exported; 197 void _r_debug_postinit(struct link_map *) __noinline __exported; 198 199 int __sys_openat(int, const char *, int, ...); 200 201 /* 202 * Data declarations. 203 */ 204 struct r_debug r_debug __exported; /* for GDB; */ 205 static bool libmap_disable; /* Disable libmap */ 206 static bool ld_loadfltr; /* Immediate filters processing */ 207 static const char *libmap_override;/* Maps to use in addition to libmap.conf */ 208 static bool trust; /* False for setuid and setgid programs */ 209 static bool dangerous_ld_env; /* True if environment variables have been 210 used to affect the libraries loaded */ 211 bool ld_bind_not; /* Disable PLT update */ 212 static const char *ld_bind_now; /* Environment variable for immediate binding */ 213 static const char *ld_debug; /* Environment variable for debugging */ 214 static bool ld_dynamic_weak = true; /* True if non-weak definition overrides 215 weak definition */ 216 static const char *ld_library_path;/* Environment variable for search path */ 217 static const char *ld_library_dirs;/* Environment variable for library descriptors */ 218 static const char *ld_preload; /* Environment variable for libraries to 219 load first */ 220 static const char *ld_preload_fds;/* Environment variable for libraries represented by 221 descriptors */ 222 static const char *ld_elf_hints_path; /* Environment variable for alternative hints path */ 223 static const char *ld_tracing; /* Called from ldd to print libs */ 224 static const char *ld_utrace; /* Use utrace() to log events. */ 225 static struct obj_entry_q obj_list; /* Queue of all loaded objects */ 226 static Obj_Entry *obj_main; /* The main program shared object */ 227 static Obj_Entry obj_rtld; /* The dynamic linker shared object */ 228 static unsigned int obj_count; /* Number of objects in obj_list */ 229 static unsigned int obj_loads; /* Number of loads of objects (gen count) */ 230 231 static Objlist list_global = /* Objects dlopened with RTLD_GLOBAL */ 232 STAILQ_HEAD_INITIALIZER(list_global); 233 static Objlist list_main = /* Objects loaded at program startup */ 234 STAILQ_HEAD_INITIALIZER(list_main); 235 static Objlist list_fini = /* Objects needing fini() calls */ 236 STAILQ_HEAD_INITIALIZER(list_fini); 237 238 Elf_Sym sym_zero; /* For resolving undefined weak refs. */ 239 240 #define GDB_STATE(s,m) r_debug.r_state = s; r_debug_state(&r_debug,m); 241 242 extern Elf_Dyn _DYNAMIC; 243 #pragma weak _DYNAMIC 244 245 int dlclose(void *) __exported; 246 char *dlerror(void) __exported; 247 void *dlopen(const char *, int) __exported; 248 void *fdlopen(int, int) __exported; 249 void *dlsym(void *, const char *) __exported; 250 dlfunc_t dlfunc(void *, const char *) __exported; 251 void *dlvsym(void *, const char *, const char *) __exported; 252 int dladdr(const void *, Dl_info *) __exported; 253 void dllockinit(void *, void *(*)(void *), void (*)(void *), void (*)(void *), 254 void (*)(void *), void (*)(void *), void (*)(void *)) __exported; 255 int dlinfo(void *, int , void *) __exported; 256 int dl_iterate_phdr(__dl_iterate_hdr_callback, void *) __exported; 257 int _rtld_addr_phdr(const void *, struct dl_phdr_info *) __exported; 258 int _rtld_get_stack_prot(void) __exported; 259 int _rtld_is_dlopened(void *) __exported; 260 void _rtld_error(const char *, ...) __exported; 261 262 /* Only here to fix -Wmissing-prototypes warnings */ 263 int __getosreldate(void); 264 func_ptr_type _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp); 265 Elf_Addr _rtld_bind(Obj_Entry *obj, Elf_Size reloff); 266 267 int npagesizes; 268 static int osreldate; 269 size_t *pagesizes; 270 size_t page_size; 271 272 static int stack_prot = PROT_READ | PROT_WRITE | PROT_EXEC; 273 static int max_stack_flags; 274 275 /* 276 * Global declarations normally provided by crt1. The dynamic linker is 277 * not built with crt1, so we have to provide them ourselves. 278 */ 279 char *__progname; 280 char **environ; 281 282 /* 283 * Used to pass argc, argv to init functions. 284 */ 285 int main_argc; 286 char **main_argv; 287 288 /* 289 * Globals to control TLS allocation. 290 */ 291 size_t tls_last_offset; /* Static TLS offset of last module */ 292 size_t tls_last_size; /* Static TLS size of last module */ 293 size_t tls_static_space; /* Static TLS space allocated */ 294 static size_t tls_static_max_align; 295 Elf_Addr tls_dtv_generation = 1; /* Used to detect when dtv size changes */ 296 int tls_max_index = 1; /* Largest module index allocated */ 297 298 static bool ld_library_path_rpath = false; 299 bool ld_fast_sigblock = false; 300 301 /* 302 * Globals for path names, and such 303 */ 304 const char *ld_elf_hints_default = _PATH_ELF_HINTS; 305 const char *ld_path_libmap_conf = _PATH_LIBMAP_CONF; 306 const char *ld_path_rtld = _PATH_RTLD; 307 const char *ld_standard_library_path = STANDARD_LIBRARY_PATH; 308 const char *ld_env_prefix = LD_; 309 310 static void (*rtld_exit_ptr)(void); 311 312 /* 313 * Fill in a DoneList with an allocation large enough to hold all of 314 * the currently-loaded objects. Keep this as a macro since it calls 315 * alloca and we want that to occur within the scope of the caller. 316 */ 317 #define donelist_init(dlp) \ 318 ((dlp)->objs = alloca(obj_count * sizeof (dlp)->objs[0]), \ 319 assert((dlp)->objs != NULL), \ 320 (dlp)->num_alloc = obj_count, \ 321 (dlp)->num_used = 0) 322 323 #define LD_UTRACE(e, h, mb, ms, r, n) do { \ 324 if (ld_utrace != NULL) \ 325 ld_utrace_log(e, h, mb, ms, r, n); \ 326 } while (0) 327 328 static void 329 ld_utrace_log(int event, void *handle, void *mapbase, size_t mapsize, 330 int refcnt, const char *name) 331 { 332 struct utrace_rtld ut; 333 static const char rtld_utrace_sig[RTLD_UTRACE_SIG_SZ] = RTLD_UTRACE_SIG; 334 335 memcpy(ut.sig, rtld_utrace_sig, sizeof(ut.sig)); 336 ut.event = event; 337 ut.handle = handle; 338 ut.mapbase = mapbase; 339 ut.mapsize = mapsize; 340 ut.refcnt = refcnt; 341 bzero(ut.name, sizeof(ut.name)); 342 if (name) 343 strlcpy(ut.name, name, sizeof(ut.name)); 344 utrace(&ut, sizeof(ut)); 345 } 346 347 enum { 348 LD_BIND_NOW = 0, 349 LD_PRELOAD, 350 LD_LIBMAP, 351 LD_LIBRARY_PATH, 352 LD_LIBRARY_PATH_FDS, 353 LD_LIBMAP_DISABLE, 354 LD_BIND_NOT, 355 LD_DEBUG, 356 LD_ELF_HINTS_PATH, 357 LD_LOADFLTR, 358 LD_LIBRARY_PATH_RPATH, 359 LD_PRELOAD_FDS, 360 LD_DYNAMIC_WEAK, 361 LD_TRACE_LOADED_OBJECTS, 362 LD_UTRACE, 363 LD_DUMP_REL_PRE, 364 LD_DUMP_REL_POST, 365 LD_TRACE_LOADED_OBJECTS_PROGNAME, 366 LD_TRACE_LOADED_OBJECTS_FMT1, 367 LD_TRACE_LOADED_OBJECTS_FMT2, 368 LD_TRACE_LOADED_OBJECTS_ALL, 369 LD_SHOW_AUXV, 370 }; 371 372 struct ld_env_var_desc { 373 const char * const n; 374 const char *val; 375 const bool unsecure; 376 }; 377 #define LD_ENV_DESC(var, unsec) \ 378 [LD_##var] = { .n = #var, .unsecure = unsec } 379 380 static struct ld_env_var_desc ld_env_vars[] = { 381 LD_ENV_DESC(BIND_NOW, false), 382 LD_ENV_DESC(PRELOAD, true), 383 LD_ENV_DESC(LIBMAP, true), 384 LD_ENV_DESC(LIBRARY_PATH, true), 385 LD_ENV_DESC(LIBRARY_PATH_FDS, true), 386 LD_ENV_DESC(LIBMAP_DISABLE, true), 387 LD_ENV_DESC(BIND_NOT, true), 388 LD_ENV_DESC(DEBUG, true), 389 LD_ENV_DESC(ELF_HINTS_PATH, true), 390 LD_ENV_DESC(LOADFLTR, true), 391 LD_ENV_DESC(LIBRARY_PATH_RPATH, true), 392 LD_ENV_DESC(PRELOAD_FDS, true), 393 LD_ENV_DESC(DYNAMIC_WEAK, true), 394 LD_ENV_DESC(TRACE_LOADED_OBJECTS, false), 395 LD_ENV_DESC(UTRACE, false), 396 LD_ENV_DESC(DUMP_REL_PRE, false), 397 LD_ENV_DESC(DUMP_REL_POST, false), 398 LD_ENV_DESC(TRACE_LOADED_OBJECTS_PROGNAME, false), 399 LD_ENV_DESC(TRACE_LOADED_OBJECTS_FMT1, false), 400 LD_ENV_DESC(TRACE_LOADED_OBJECTS_FMT2, false), 401 LD_ENV_DESC(TRACE_LOADED_OBJECTS_ALL, false), 402 LD_ENV_DESC(SHOW_AUXV, false), 403 }; 404 405 static const char * 406 ld_get_env_var(int idx) 407 { 408 return (ld_env_vars[idx].val); 409 } 410 411 static const char * 412 rtld_get_env_val(char **env, const char *name, size_t name_len) 413 { 414 char **m, *n, *v; 415 416 for (m = env; *m != NULL; m++) { 417 n = *m; 418 v = strchr(n, '='); 419 if (v == NULL) { 420 /* corrupt environment? */ 421 continue; 422 } 423 if (v - n == (ptrdiff_t)name_len && 424 strncmp(name, n, name_len) == 0) 425 return (v + 1); 426 } 427 return (NULL); 428 } 429 430 static void 431 rtld_init_env_vars_for_prefix(char **env, const char *env_prefix) 432 { 433 struct ld_env_var_desc *lvd; 434 size_t prefix_len, nlen; 435 char **m, *n, *v; 436 int i; 437 438 prefix_len = strlen(env_prefix); 439 for (m = env; *m != NULL; m++) { 440 n = *m; 441 if (strncmp(env_prefix, n, prefix_len) != 0) { 442 /* Not a rtld environment variable. */ 443 continue; 444 } 445 n += prefix_len; 446 v = strchr(n, '='); 447 if (v == NULL) { 448 /* corrupt environment? */ 449 continue; 450 } 451 for (i = 0; i < (int)nitems(ld_env_vars); i++) { 452 lvd = &ld_env_vars[i]; 453 if (lvd->val != NULL) { 454 /* Saw higher-priority variable name already. */ 455 continue; 456 } 457 nlen = strlen(lvd->n); 458 if (v - n == (ptrdiff_t)nlen && 459 strncmp(lvd->n, n, nlen) == 0) { 460 lvd->val = v + 1; 461 break; 462 } 463 } 464 } 465 } 466 467 static void 468 rtld_init_env_vars(char **env) 469 { 470 rtld_init_env_vars_for_prefix(env, ld_env_prefix); 471 } 472 473 static void 474 set_ld_elf_hints_path(void) 475 { 476 if (ld_elf_hints_path == NULL || strlen(ld_elf_hints_path) == 0) 477 ld_elf_hints_path = ld_elf_hints_default; 478 } 479 480 uintptr_t 481 rtld_round_page(uintptr_t x) 482 { 483 return (roundup2(x, page_size)); 484 } 485 486 uintptr_t 487 rtld_trunc_page(uintptr_t x) 488 { 489 return (rounddown2(x, page_size)); 490 } 491 492 /* 493 * Main entry point for dynamic linking. The first argument is the 494 * stack pointer. The stack is expected to be laid out as described 495 * in the SVR4 ABI specification, Intel 386 Processor Supplement. 496 * Specifically, the stack pointer points to a word containing 497 * ARGC. Following that in the stack is a null-terminated sequence 498 * of pointers to argument strings. Then comes a null-terminated 499 * sequence of pointers to environment strings. Finally, there is a 500 * sequence of "auxiliary vector" entries. 501 * 502 * The second argument points to a place to store the dynamic linker's 503 * exit procedure pointer and the third to a place to store the main 504 * program's object. 505 * 506 * The return value is the main program's entry point. 507 */ 508 func_ptr_type 509 _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp) 510 { 511 Elf_Auxinfo *aux, *auxp, *auxpf, *aux_info[AT_COUNT]; 512 Objlist_Entry *entry; 513 Obj_Entry *last_interposer, *obj, *preload_tail; 514 const Elf_Phdr *phdr; 515 Objlist initlist; 516 RtldLockState lockstate; 517 struct stat st; 518 Elf_Addr *argcp; 519 char **argv, **env, **envp, *kexecpath; 520 const char *argv0, *binpath, *library_path_rpath; 521 struct ld_env_var_desc *lvd; 522 caddr_t imgentry; 523 char buf[MAXPATHLEN]; 524 int argc, fd, i, mib[4], old_osrel, osrel, phnum, rtld_argc; 525 size_t sz; 526 #ifdef __powerpc__ 527 int old_auxv_format = 1; 528 #endif 529 bool dir_enable, dir_ignore, direct_exec, explicit_fd, search_in_path; 530 531 /* 532 * On entry, the dynamic linker itself has not been relocated yet. 533 * Be very careful not to reference any global data until after 534 * init_rtld has returned. It is OK to reference file-scope statics 535 * and string constants, and to call static and global functions. 536 */ 537 538 /* Find the auxiliary vector on the stack. */ 539 argcp = sp; 540 argc = *sp++; 541 argv = (char **) sp; 542 sp += argc + 1; /* Skip over arguments and NULL terminator */ 543 env = (char **) sp; 544 while (*sp++ != 0) /* Skip over environment, and NULL terminator */ 545 ; 546 aux = (Elf_Auxinfo *) sp; 547 548 /* Digest the auxiliary vector. */ 549 for (i = 0; i < AT_COUNT; i++) 550 aux_info[i] = NULL; 551 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) { 552 if (auxp->a_type < AT_COUNT) 553 aux_info[auxp->a_type] = auxp; 554 #ifdef __powerpc__ 555 if (auxp->a_type == 23) /* AT_STACKPROT */ 556 old_auxv_format = 0; 557 #endif 558 } 559 560 #ifdef __powerpc__ 561 if (old_auxv_format) { 562 /* Remap from old-style auxv numbers. */ 563 aux_info[23] = aux_info[21]; /* AT_STACKPROT */ 564 aux_info[21] = aux_info[19]; /* AT_PAGESIZESLEN */ 565 aux_info[19] = aux_info[17]; /* AT_NCPUS */ 566 aux_info[17] = aux_info[15]; /* AT_CANARYLEN */ 567 aux_info[15] = aux_info[13]; /* AT_EXECPATH */ 568 aux_info[13] = NULL; /* AT_GID */ 569 570 aux_info[20] = aux_info[18]; /* AT_PAGESIZES */ 571 aux_info[18] = aux_info[16]; /* AT_OSRELDATE */ 572 aux_info[16] = aux_info[14]; /* AT_CANARY */ 573 aux_info[14] = NULL; /* AT_EGID */ 574 } 575 #endif 576 577 /* Initialize and relocate ourselves. */ 578 assert(aux_info[AT_BASE] != NULL); 579 init_rtld((caddr_t) aux_info[AT_BASE]->a_un.a_ptr, aux_info); 580 581 dlerror_dflt_init(); 582 583 __progname = obj_rtld.path; 584 argv0 = argv[0] != NULL ? argv[0] : "(null)"; 585 environ = env; 586 main_argc = argc; 587 main_argv = argv; 588 589 if (aux_info[AT_BSDFLAGS] != NULL && 590 (aux_info[AT_BSDFLAGS]->a_un.a_val & ELF_BSDF_SIGFASTBLK) != 0) 591 ld_fast_sigblock = true; 592 593 trust = !issetugid(); 594 direct_exec = false; 595 596 md_abi_variant_hook(aux_info); 597 rtld_init_env_vars(env); 598 599 fd = -1; 600 if (aux_info[AT_EXECFD] != NULL) { 601 fd = aux_info[AT_EXECFD]->a_un.a_val; 602 } else { 603 assert(aux_info[AT_PHDR] != NULL); 604 phdr = (const Elf_Phdr *)aux_info[AT_PHDR]->a_un.a_ptr; 605 if (phdr == obj_rtld.phdr) { 606 if (!trust) { 607 _rtld_error("Tainted process refusing to run binary %s", 608 argv0); 609 rtld_die(); 610 } 611 direct_exec = true; 612 613 dbg("opening main program in direct exec mode"); 614 if (argc >= 2) { 615 rtld_argc = parse_args(argv, argc, &search_in_path, &fd, 616 &argv0, &dir_ignore); 617 explicit_fd = (fd != -1); 618 binpath = NULL; 619 if (!explicit_fd) 620 fd = open_binary_fd(argv0, search_in_path, &binpath); 621 if (fstat(fd, &st) == -1) { 622 _rtld_error("Failed to fstat FD %d (%s): %s", fd, 623 explicit_fd ? "user-provided descriptor" : argv0, 624 rtld_strerror(errno)); 625 rtld_die(); 626 } 627 628 /* 629 * Rough emulation of the permission checks done by 630 * execve(2), only Unix DACs are checked, ACLs are 631 * ignored. Preserve the semantic of disabling owner 632 * to execute if owner x bit is cleared, even if 633 * others x bit is enabled. 634 * mmap(2) does not allow to mmap with PROT_EXEC if 635 * binary' file comes from noexec mount. We cannot 636 * set a text reference on the binary. 637 */ 638 dir_enable = false; 639 if (st.st_uid == geteuid()) { 640 if ((st.st_mode & S_IXUSR) != 0) 641 dir_enable = true; 642 } else if (st.st_gid == getegid()) { 643 if ((st.st_mode & S_IXGRP) != 0) 644 dir_enable = true; 645 } else if ((st.st_mode & S_IXOTH) != 0) { 646 dir_enable = true; 647 } 648 if (!dir_enable && !dir_ignore) { 649 _rtld_error("No execute permission for binary %s", 650 argv0); 651 rtld_die(); 652 } 653 654 /* 655 * For direct exec mode, argv[0] is the interpreter 656 * name, we must remove it and shift arguments left 657 * before invoking binary main. Since stack layout 658 * places environment pointers and aux vectors right 659 * after the terminating NULL, we must shift 660 * environment and aux as well. 661 */ 662 main_argc = argc - rtld_argc; 663 for (i = 0; i <= main_argc; i++) 664 argv[i] = argv[i + rtld_argc]; 665 *argcp -= rtld_argc; 666 environ = env = envp = argv + main_argc + 1; 667 dbg("move env from %p to %p", envp + rtld_argc, envp); 668 do { 669 *envp = *(envp + rtld_argc); 670 } while (*envp++ != NULL); 671 aux = auxp = (Elf_Auxinfo *)envp; 672 auxpf = (Elf_Auxinfo *)(envp + rtld_argc); 673 dbg("move aux from %p to %p", auxpf, aux); 674 /* XXXKIB insert place for AT_EXECPATH if not present */ 675 for (;; auxp++, auxpf++) { 676 *auxp = *auxpf; 677 if (auxp->a_type == AT_NULL) 678 break; 679 } 680 /* Since the auxiliary vector has moved, redigest it. */ 681 for (i = 0; i < AT_COUNT; i++) 682 aux_info[i] = NULL; 683 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) { 684 if (auxp->a_type < AT_COUNT) 685 aux_info[auxp->a_type] = auxp; 686 } 687 688 /* Point AT_EXECPATH auxv and aux_info to the binary path. */ 689 if (binpath == NULL) { 690 aux_info[AT_EXECPATH] = NULL; 691 } else { 692 if (aux_info[AT_EXECPATH] == NULL) { 693 aux_info[AT_EXECPATH] = xmalloc(sizeof(Elf_Auxinfo)); 694 aux_info[AT_EXECPATH]->a_type = AT_EXECPATH; 695 } 696 aux_info[AT_EXECPATH]->a_un.a_ptr = __DECONST(void *, 697 binpath); 698 } 699 } else { 700 _rtld_error("No binary"); 701 rtld_die(); 702 } 703 } 704 } 705 706 ld_bind_now = ld_get_env_var(LD_BIND_NOW); 707 708 /* 709 * If the process is tainted, then we un-set the dangerous environment 710 * variables. The process will be marked as tainted until setuid(2) 711 * is called. If any child process calls setuid(2) we do not want any 712 * future processes to honor the potentially un-safe variables. 713 */ 714 if (!trust) { 715 for (i = 0; i < (int)nitems(ld_env_vars); i++) { 716 lvd = &ld_env_vars[i]; 717 if (lvd->unsecure) 718 lvd->val = NULL; 719 } 720 } 721 722 ld_debug = ld_get_env_var(LD_DEBUG); 723 if (ld_bind_now == NULL) 724 ld_bind_not = ld_get_env_var(LD_BIND_NOT) != NULL; 725 ld_dynamic_weak = ld_get_env_var(LD_DYNAMIC_WEAK) == NULL; 726 libmap_disable = ld_get_env_var(LD_LIBMAP_DISABLE) != NULL; 727 libmap_override = ld_get_env_var(LD_LIBMAP); 728 ld_library_path = ld_get_env_var(LD_LIBRARY_PATH); 729 ld_library_dirs = ld_get_env_var(LD_LIBRARY_PATH_FDS); 730 ld_preload = ld_get_env_var(LD_PRELOAD); 731 ld_preload_fds = ld_get_env_var(LD_PRELOAD_FDS); 732 ld_elf_hints_path = ld_get_env_var(LD_ELF_HINTS_PATH); 733 ld_loadfltr = ld_get_env_var(LD_LOADFLTR) != NULL; 734 library_path_rpath = ld_get_env_var(LD_LIBRARY_PATH_RPATH); 735 if (library_path_rpath != NULL) { 736 if (library_path_rpath[0] == 'y' || 737 library_path_rpath[0] == 'Y' || 738 library_path_rpath[0] == '1') 739 ld_library_path_rpath = true; 740 else 741 ld_library_path_rpath = false; 742 } 743 dangerous_ld_env = libmap_disable || libmap_override != NULL || 744 ld_library_path != NULL || ld_preload != NULL || 745 ld_elf_hints_path != NULL || ld_loadfltr || !ld_dynamic_weak; 746 ld_tracing = ld_get_env_var(LD_TRACE_LOADED_OBJECTS); 747 ld_utrace = ld_get_env_var(LD_UTRACE); 748 749 set_ld_elf_hints_path(); 750 if (ld_debug != NULL && *ld_debug != '\0') 751 debug = 1; 752 dbg("%s is initialized, base address = %p", __progname, 753 (caddr_t) aux_info[AT_BASE]->a_un.a_ptr); 754 dbg("RTLD dynamic = %p", obj_rtld.dynamic); 755 dbg("RTLD pltgot = %p", obj_rtld.pltgot); 756 757 dbg("initializing thread locks"); 758 lockdflt_init(); 759 760 /* 761 * Load the main program, or process its program header if it is 762 * already loaded. 763 */ 764 if (fd != -1) { /* Load the main program. */ 765 dbg("loading main program"); 766 obj_main = map_object(fd, argv0, NULL); 767 close(fd); 768 if (obj_main == NULL) 769 rtld_die(); 770 max_stack_flags = obj_main->stack_flags; 771 } else { /* Main program already loaded. */ 772 dbg("processing main program's program header"); 773 assert(aux_info[AT_PHDR] != NULL); 774 phdr = (const Elf_Phdr *) aux_info[AT_PHDR]->a_un.a_ptr; 775 assert(aux_info[AT_PHNUM] != NULL); 776 phnum = aux_info[AT_PHNUM]->a_un.a_val; 777 assert(aux_info[AT_PHENT] != NULL); 778 assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr)); 779 assert(aux_info[AT_ENTRY] != NULL); 780 imgentry = (caddr_t) aux_info[AT_ENTRY]->a_un.a_ptr; 781 if ((obj_main = digest_phdr(phdr, phnum, imgentry, argv0)) == NULL) 782 rtld_die(); 783 } 784 785 if (aux_info[AT_EXECPATH] != NULL && fd == -1) { 786 kexecpath = aux_info[AT_EXECPATH]->a_un.a_ptr; 787 dbg("AT_EXECPATH %p %s", kexecpath, kexecpath); 788 if (kexecpath[0] == '/') 789 obj_main->path = kexecpath; 790 else if (getcwd(buf, sizeof(buf)) == NULL || 791 strlcat(buf, "/", sizeof(buf)) >= sizeof(buf) || 792 strlcat(buf, kexecpath, sizeof(buf)) >= sizeof(buf)) 793 obj_main->path = xstrdup(argv0); 794 else 795 obj_main->path = xstrdup(buf); 796 } else { 797 dbg("No AT_EXECPATH or direct exec"); 798 obj_main->path = xstrdup(argv0); 799 } 800 dbg("obj_main path %s", obj_main->path); 801 obj_main->mainprog = true; 802 803 if (aux_info[AT_STACKPROT] != NULL && 804 aux_info[AT_STACKPROT]->a_un.a_val != 0) 805 stack_prot = aux_info[AT_STACKPROT]->a_un.a_val; 806 807 #ifndef COMPAT_libcompat 808 /* 809 * Get the actual dynamic linker pathname from the executable if 810 * possible. (It should always be possible.) That ensures that 811 * gdb will find the right dynamic linker even if a non-standard 812 * one is being used. 813 */ 814 if (obj_main->interp != NULL && 815 strcmp(obj_main->interp, obj_rtld.path) != 0) { 816 free(obj_rtld.path); 817 obj_rtld.path = xstrdup(obj_main->interp); 818 __progname = obj_rtld.path; 819 } 820 #endif 821 822 if (!digest_dynamic(obj_main, 0)) 823 rtld_die(); 824 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", 825 obj_main->path, obj_main->valid_hash_sysv, obj_main->valid_hash_gnu, 826 obj_main->dynsymcount); 827 828 linkmap_add(obj_main); 829 linkmap_add(&obj_rtld); 830 831 /* Link the main program into the list of objects. */ 832 TAILQ_INSERT_HEAD(&obj_list, obj_main, next); 833 obj_count++; 834 obj_loads++; 835 836 /* Initialize a fake symbol for resolving undefined weak references. */ 837 sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE); 838 sym_zero.st_shndx = SHN_UNDEF; 839 sym_zero.st_value = -(uintptr_t)obj_main->relocbase; 840 841 if (!libmap_disable) 842 libmap_disable = (bool)lm_init(libmap_override); 843 844 if (aux_info[AT_KPRELOAD] != NULL && 845 aux_info[AT_KPRELOAD]->a_un.a_ptr != NULL) { 846 dbg("loading kernel vdso"); 847 if (load_kpreload(aux_info[AT_KPRELOAD]->a_un.a_ptr) == -1) 848 rtld_die(); 849 } 850 851 dbg("loading LD_PRELOAD_FDS libraries"); 852 if (load_preload_objects(ld_preload_fds, true) == -1) 853 rtld_die(); 854 855 dbg("loading LD_PRELOAD libraries"); 856 if (load_preload_objects(ld_preload, false) == -1) 857 rtld_die(); 858 preload_tail = globallist_curr(TAILQ_LAST(&obj_list, obj_entry_q)); 859 860 dbg("loading needed objects"); 861 if (load_needed_objects(obj_main, ld_tracing != NULL ? RTLD_LO_TRACE : 862 0) == -1) 863 rtld_die(); 864 865 /* Make a list of all objects loaded at startup. */ 866 last_interposer = obj_main; 867 TAILQ_FOREACH(obj, &obj_list, next) { 868 if (obj->marker) 869 continue; 870 if (obj->z_interpose && obj != obj_main) { 871 objlist_put_after(&list_main, last_interposer, obj); 872 last_interposer = obj; 873 } else { 874 objlist_push_tail(&list_main, obj); 875 } 876 obj->refcount++; 877 } 878 879 dbg("checking for required versions"); 880 if (rtld_verify_versions(&list_main) == -1 && !ld_tracing) 881 rtld_die(); 882 883 if (ld_get_env_var(LD_SHOW_AUXV) != NULL) 884 dump_auxv(aux_info); 885 886 if (ld_tracing) { /* We're done */ 887 trace_loaded_objects(obj_main, true); 888 exit(0); 889 } 890 891 if (ld_get_env_var(LD_DUMP_REL_PRE) != NULL) { 892 dump_relocations(obj_main); 893 exit (0); 894 } 895 896 /* 897 * Processing tls relocations requires having the tls offsets 898 * initialized. Prepare offsets before starting initial 899 * relocation processing. 900 */ 901 dbg("initializing initial thread local storage offsets"); 902 STAILQ_FOREACH(entry, &list_main, link) { 903 /* 904 * Allocate all the initial objects out of the static TLS 905 * block even if they didn't ask for it. 906 */ 907 allocate_tls_offset(entry->obj); 908 } 909 910 if (relocate_objects(obj_main, 911 ld_bind_now != NULL && *ld_bind_now != '\0', 912 &obj_rtld, SYMLOOK_EARLY, NULL) == -1) 913 rtld_die(); 914 915 dbg("doing copy relocations"); 916 if (do_copy_relocations(obj_main) == -1) 917 rtld_die(); 918 919 if (ld_get_env_var(LD_DUMP_REL_POST) != NULL) { 920 dump_relocations(obj_main); 921 exit (0); 922 } 923 924 ifunc_init(aux); 925 926 /* 927 * Setup TLS for main thread. This must be done after the 928 * relocations are processed, since tls initialization section 929 * might be the subject for relocations. 930 */ 931 dbg("initializing initial thread local storage"); 932 allocate_initial_tls(globallist_curr(TAILQ_FIRST(&obj_list))); 933 934 dbg("initializing key program variables"); 935 set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : ""); 936 set_program_var("environ", env); 937 set_program_var("__elf_aux_vector", aux); 938 939 /* Make a list of init functions to call. */ 940 objlist_init(&initlist); 941 initlist_add_objects(globallist_curr(TAILQ_FIRST(&obj_list)), 942 preload_tail, &initlist); 943 944 r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */ 945 946 map_stacks_exec(NULL); 947 948 if (!obj_main->crt_no_init) { 949 /* 950 * Make sure we don't call the main program's init and fini 951 * functions for binaries linked with old crt1 which calls 952 * _init itself. 953 */ 954 obj_main->init = obj_main->fini = (Elf_Addr)NULL; 955 obj_main->preinit_array = obj_main->init_array = 956 obj_main->fini_array = (Elf_Addr)NULL; 957 } 958 959 if (direct_exec) { 960 /* Set osrel for direct-execed binary */ 961 mib[0] = CTL_KERN; 962 mib[1] = KERN_PROC; 963 mib[2] = KERN_PROC_OSREL; 964 mib[3] = getpid(); 965 osrel = obj_main->osrel; 966 sz = sizeof(old_osrel); 967 dbg("setting osrel to %d", osrel); 968 (void)sysctl(mib, 4, &old_osrel, &sz, &osrel, sizeof(osrel)); 969 } 970 971 wlock_acquire(rtld_bind_lock, &lockstate); 972 973 dbg("resolving ifuncs"); 974 if (initlist_objects_ifunc(&initlist, ld_bind_now != NULL && 975 *ld_bind_now != '\0', SYMLOOK_EARLY, &lockstate) == -1) 976 rtld_die(); 977 978 rtld_exit_ptr = rtld_exit; 979 if (obj_main->crt_no_init) 980 preinit_main(); 981 objlist_call_init(&initlist, &lockstate); 982 _r_debug_postinit(&obj_main->linkmap); 983 objlist_clear(&initlist); 984 dbg("loading filtees"); 985 TAILQ_FOREACH(obj, &obj_list, next) { 986 if (obj->marker) 987 continue; 988 if (ld_loadfltr || obj->z_loadfltr) 989 load_filtees(obj, 0, &lockstate); 990 } 991 992 dbg("enforcing main obj relro"); 993 if (obj_enforce_relro(obj_main) == -1) 994 rtld_die(); 995 996 lock_release(rtld_bind_lock, &lockstate); 997 998 dbg("transferring control to program entry point = %p", obj_main->entry); 999 1000 /* Return the exit procedure and the program entry point. */ 1001 *exit_proc = rtld_exit_ptr; 1002 *objp = obj_main; 1003 return ((func_ptr_type)obj_main->entry); 1004 } 1005 1006 void * 1007 rtld_resolve_ifunc(const Obj_Entry *obj, const Elf_Sym *def) 1008 { 1009 void *ptr; 1010 Elf_Addr target; 1011 1012 ptr = (void *)make_function_pointer(def, obj); 1013 target = call_ifunc_resolver(ptr); 1014 return ((void *)target); 1015 } 1016 1017 Elf_Addr 1018 _rtld_bind(Obj_Entry *obj, Elf_Size reloff) 1019 { 1020 const Elf_Rel *rel; 1021 const Elf_Sym *def; 1022 const Obj_Entry *defobj; 1023 Elf_Addr *where; 1024 Elf_Addr target; 1025 RtldLockState lockstate; 1026 1027 rlock_acquire(rtld_bind_lock, &lockstate); 1028 if (sigsetjmp(lockstate.env, 0) != 0) 1029 lock_upgrade(rtld_bind_lock, &lockstate); 1030 if (obj->pltrel) 1031 rel = (const Elf_Rel *)((const char *)obj->pltrel + reloff); 1032 else 1033 rel = (const Elf_Rel *)((const char *)obj->pltrela + reloff); 1034 1035 where = (Elf_Addr *)(obj->relocbase + rel->r_offset); 1036 def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, SYMLOOK_IN_PLT, 1037 NULL, &lockstate); 1038 if (def == NULL) 1039 rtld_die(); 1040 if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 1041 target = (Elf_Addr)rtld_resolve_ifunc(defobj, def); 1042 else 1043 target = (Elf_Addr)(defobj->relocbase + def->st_value); 1044 1045 dbg("\"%s\" in \"%s\" ==> %p in \"%s\"", 1046 defobj->strtab + def->st_name, 1047 obj->path == NULL ? NULL : basename(obj->path), 1048 (void *)target, 1049 defobj->path == NULL ? NULL : basename(defobj->path)); 1050 1051 /* 1052 * Write the new contents for the jmpslot. Note that depending on 1053 * architecture, the value which we need to return back to the 1054 * lazy binding trampoline may or may not be the target 1055 * address. The value returned from reloc_jmpslot() is the value 1056 * that the trampoline needs. 1057 */ 1058 target = reloc_jmpslot(where, target, defobj, obj, rel); 1059 lock_release(rtld_bind_lock, &lockstate); 1060 return (target); 1061 } 1062 1063 /* 1064 * Error reporting function. Use it like printf. If formats the message 1065 * into a buffer, and sets things up so that the next call to dlerror() 1066 * will return the message. 1067 */ 1068 void 1069 _rtld_error(const char *fmt, ...) 1070 { 1071 va_list ap; 1072 1073 va_start(ap, fmt); 1074 rtld_vsnprintf(lockinfo.dlerror_loc(), lockinfo.dlerror_loc_sz, 1075 fmt, ap); 1076 va_end(ap); 1077 *lockinfo.dlerror_seen() = 0; 1078 LD_UTRACE(UTRACE_RTLD_ERROR, NULL, NULL, 0, 0, lockinfo.dlerror_loc()); 1079 } 1080 1081 /* 1082 * Return a dynamically-allocated copy of the current error message, if any. 1083 */ 1084 static struct dlerror_save * 1085 errmsg_save(void) 1086 { 1087 struct dlerror_save *res; 1088 1089 res = xmalloc(sizeof(*res)); 1090 res->seen = *lockinfo.dlerror_seen(); 1091 if (res->seen == 0) 1092 res->msg = xstrdup(lockinfo.dlerror_loc()); 1093 return (res); 1094 } 1095 1096 /* 1097 * Restore the current error message from a copy which was previously saved 1098 * by errmsg_save(). The copy is freed. 1099 */ 1100 static void 1101 errmsg_restore(struct dlerror_save *saved_msg) 1102 { 1103 if (saved_msg == NULL || saved_msg->seen == 1) { 1104 *lockinfo.dlerror_seen() = 1; 1105 } else { 1106 *lockinfo.dlerror_seen() = 0; 1107 strlcpy(lockinfo.dlerror_loc(), saved_msg->msg, 1108 lockinfo.dlerror_loc_sz); 1109 free(saved_msg->msg); 1110 } 1111 free(saved_msg); 1112 } 1113 1114 static const char * 1115 basename(const char *name) 1116 { 1117 const char *p; 1118 1119 p = strrchr(name, '/'); 1120 return (p != NULL ? p + 1 : name); 1121 } 1122 1123 static struct utsname uts; 1124 1125 static char * 1126 origin_subst_one(Obj_Entry *obj, char *real, const char *kw, 1127 const char *subst, bool may_free) 1128 { 1129 char *p, *p1, *res, *resp; 1130 int subst_len, kw_len, subst_count, old_len, new_len; 1131 1132 kw_len = strlen(kw); 1133 1134 /* 1135 * First, count the number of the keyword occurrences, to 1136 * preallocate the final string. 1137 */ 1138 for (p = real, subst_count = 0;; p = p1 + kw_len, subst_count++) { 1139 p1 = strstr(p, kw); 1140 if (p1 == NULL) 1141 break; 1142 } 1143 1144 /* 1145 * If the keyword is not found, just return. 1146 * 1147 * Return non-substituted string if resolution failed. We 1148 * cannot do anything more reasonable, the failure mode of the 1149 * caller is unresolved library anyway. 1150 */ 1151 if (subst_count == 0 || (obj != NULL && !obj_resolve_origin(obj))) 1152 return (may_free ? real : xstrdup(real)); 1153 if (obj != NULL) 1154 subst = obj->origin_path; 1155 1156 /* 1157 * There is indeed something to substitute. Calculate the 1158 * length of the resulting string, and allocate it. 1159 */ 1160 subst_len = strlen(subst); 1161 old_len = strlen(real); 1162 new_len = old_len + (subst_len - kw_len) * subst_count; 1163 res = xmalloc(new_len + 1); 1164 1165 /* 1166 * Now, execute the substitution loop. 1167 */ 1168 for (p = real, resp = res, *resp = '\0';;) { 1169 p1 = strstr(p, kw); 1170 if (p1 != NULL) { 1171 /* Copy the prefix before keyword. */ 1172 memcpy(resp, p, p1 - p); 1173 resp += p1 - p; 1174 /* Keyword replacement. */ 1175 memcpy(resp, subst, subst_len); 1176 resp += subst_len; 1177 *resp = '\0'; 1178 p = p1 + kw_len; 1179 } else 1180 break; 1181 } 1182 1183 /* Copy to the end of string and finish. */ 1184 strcat(resp, p); 1185 if (may_free) 1186 free(real); 1187 return (res); 1188 } 1189 1190 static const struct { 1191 const char *kw; 1192 bool pass_obj; 1193 const char *subst; 1194 } tokens[] = { 1195 { .kw = "$ORIGIN", .pass_obj = true, .subst = NULL }, 1196 { .kw = "${ORIGIN}", .pass_obj = true, .subst = NULL }, 1197 { .kw = "$OSNAME", .pass_obj = false, .subst = uts.sysname }, 1198 { .kw = "${OSNAME}", .pass_obj = false, .subst = uts.sysname }, 1199 { .kw = "$OSREL", .pass_obj = false, .subst = uts.release }, 1200 { .kw = "${OSREL}", .pass_obj = false, .subst = uts.release }, 1201 { .kw = "$PLATFORM", .pass_obj = false, .subst = uts.machine }, 1202 { .kw = "${PLATFORM}", .pass_obj = false, .subst = uts.machine }, 1203 { .kw = "$LIB", .pass_obj = false, .subst = TOKEN_LIB }, 1204 { .kw = "${LIB}", .pass_obj = false, .subst = TOKEN_LIB }, 1205 }; 1206 1207 static char * 1208 origin_subst(Obj_Entry *obj, const char *real) 1209 { 1210 char *res; 1211 int i; 1212 1213 if (obj == NULL || !trust) 1214 return (xstrdup(real)); 1215 if (uts.sysname[0] == '\0') { 1216 if (uname(&uts) != 0) { 1217 _rtld_error("utsname failed: %d", errno); 1218 return (NULL); 1219 } 1220 } 1221 1222 /* __DECONST is safe here since without may_free real is unchanged */ 1223 res = __DECONST(char *, real); 1224 for (i = 0; i < (int)nitems(tokens); i++) { 1225 res = origin_subst_one(tokens[i].pass_obj ? obj : NULL, 1226 res, tokens[i].kw, tokens[i].subst, i != 0); 1227 } 1228 return (res); 1229 } 1230 1231 void 1232 rtld_die(void) 1233 { 1234 const char *msg = dlerror(); 1235 1236 if (msg == NULL) 1237 msg = "Fatal error"; 1238 rtld_fdputstr(STDERR_FILENO, _BASENAME_RTLD ": "); 1239 rtld_fdputstr(STDERR_FILENO, msg); 1240 rtld_fdputchar(STDERR_FILENO, '\n'); 1241 _exit(1); 1242 } 1243 1244 /* 1245 * Process a shared object's DYNAMIC section, and save the important 1246 * information in its Obj_Entry structure. 1247 */ 1248 static void 1249 digest_dynamic1(Obj_Entry *obj, int early, const Elf_Dyn **dyn_rpath, 1250 const Elf_Dyn **dyn_soname, const Elf_Dyn **dyn_runpath) 1251 { 1252 const Elf_Dyn *dynp; 1253 Needed_Entry **needed_tail = &obj->needed; 1254 Needed_Entry **needed_filtees_tail = &obj->needed_filtees; 1255 Needed_Entry **needed_aux_filtees_tail = &obj->needed_aux_filtees; 1256 const Elf_Hashelt *hashtab; 1257 const Elf32_Word *hashval; 1258 Elf32_Word bkt, nmaskwords; 1259 int bloom_size32; 1260 int plttype = DT_REL; 1261 1262 *dyn_rpath = NULL; 1263 *dyn_soname = NULL; 1264 *dyn_runpath = NULL; 1265 1266 obj->bind_now = false; 1267 dynp = obj->dynamic; 1268 if (dynp == NULL) 1269 return; 1270 for (; dynp->d_tag != DT_NULL; dynp++) { 1271 switch (dynp->d_tag) { 1272 1273 case DT_REL: 1274 obj->rel = (const Elf_Rel *)(obj->relocbase + dynp->d_un.d_ptr); 1275 break; 1276 1277 case DT_RELSZ: 1278 obj->relsize = dynp->d_un.d_val; 1279 break; 1280 1281 case DT_RELENT: 1282 assert(dynp->d_un.d_val == sizeof(Elf_Rel)); 1283 break; 1284 1285 case DT_JMPREL: 1286 obj->pltrel = (const Elf_Rel *) 1287 (obj->relocbase + dynp->d_un.d_ptr); 1288 break; 1289 1290 case DT_PLTRELSZ: 1291 obj->pltrelsize = dynp->d_un.d_val; 1292 break; 1293 1294 case DT_RELA: 1295 obj->rela = (const Elf_Rela *)(obj->relocbase + dynp->d_un.d_ptr); 1296 break; 1297 1298 case DT_RELASZ: 1299 obj->relasize = dynp->d_un.d_val; 1300 break; 1301 1302 case DT_RELAENT: 1303 assert(dynp->d_un.d_val == sizeof(Elf_Rela)); 1304 break; 1305 1306 case DT_RELR: 1307 obj->relr = (const Elf_Relr *)(obj->relocbase + dynp->d_un.d_ptr); 1308 break; 1309 1310 case DT_RELRSZ: 1311 obj->relrsize = dynp->d_un.d_val; 1312 break; 1313 1314 case DT_RELRENT: 1315 assert(dynp->d_un.d_val == sizeof(Elf_Relr)); 1316 break; 1317 1318 case DT_PLTREL: 1319 plttype = dynp->d_un.d_val; 1320 assert(dynp->d_un.d_val == DT_REL || plttype == DT_RELA); 1321 break; 1322 1323 case DT_SYMTAB: 1324 obj->symtab = (const Elf_Sym *) 1325 (obj->relocbase + dynp->d_un.d_ptr); 1326 break; 1327 1328 case DT_SYMENT: 1329 assert(dynp->d_un.d_val == sizeof(Elf_Sym)); 1330 break; 1331 1332 case DT_STRTAB: 1333 obj->strtab = (const char *)(obj->relocbase + dynp->d_un.d_ptr); 1334 break; 1335 1336 case DT_STRSZ: 1337 obj->strsize = dynp->d_un.d_val; 1338 break; 1339 1340 case DT_VERNEED: 1341 obj->verneed = (const Elf_Verneed *)(obj->relocbase + 1342 dynp->d_un.d_val); 1343 break; 1344 1345 case DT_VERNEEDNUM: 1346 obj->verneednum = dynp->d_un.d_val; 1347 break; 1348 1349 case DT_VERDEF: 1350 obj->verdef = (const Elf_Verdef *)(obj->relocbase + 1351 dynp->d_un.d_val); 1352 break; 1353 1354 case DT_VERDEFNUM: 1355 obj->verdefnum = dynp->d_un.d_val; 1356 break; 1357 1358 case DT_VERSYM: 1359 obj->versyms = (const Elf_Versym *)(obj->relocbase + 1360 dynp->d_un.d_val); 1361 break; 1362 1363 case DT_HASH: 1364 { 1365 hashtab = (const Elf_Hashelt *)(obj->relocbase + 1366 dynp->d_un.d_ptr); 1367 obj->nbuckets = hashtab[0]; 1368 obj->nchains = hashtab[1]; 1369 obj->buckets = hashtab + 2; 1370 obj->chains = obj->buckets + obj->nbuckets; 1371 obj->valid_hash_sysv = obj->nbuckets > 0 && obj->nchains > 0 && 1372 obj->buckets != NULL; 1373 } 1374 break; 1375 1376 case DT_GNU_HASH: 1377 { 1378 hashtab = (const Elf_Hashelt *)(obj->relocbase + 1379 dynp->d_un.d_ptr); 1380 obj->nbuckets_gnu = hashtab[0]; 1381 obj->symndx_gnu = hashtab[1]; 1382 nmaskwords = hashtab[2]; 1383 bloom_size32 = (__ELF_WORD_SIZE / 32) * nmaskwords; 1384 obj->maskwords_bm_gnu = nmaskwords - 1; 1385 obj->shift2_gnu = hashtab[3]; 1386 obj->bloom_gnu = (const Elf_Addr *)(hashtab + 4); 1387 obj->buckets_gnu = hashtab + 4 + bloom_size32; 1388 obj->chain_zero_gnu = obj->buckets_gnu + obj->nbuckets_gnu - 1389 obj->symndx_gnu; 1390 /* Number of bitmask words is required to be power of 2 */ 1391 obj->valid_hash_gnu = powerof2(nmaskwords) && 1392 obj->nbuckets_gnu > 0 && obj->buckets_gnu != NULL; 1393 } 1394 break; 1395 1396 case DT_NEEDED: 1397 if (!obj->rtld) { 1398 Needed_Entry *nep = NEW(Needed_Entry); 1399 nep->name = dynp->d_un.d_val; 1400 nep->obj = NULL; 1401 nep->next = NULL; 1402 1403 *needed_tail = nep; 1404 needed_tail = &nep->next; 1405 } 1406 break; 1407 1408 case DT_FILTER: 1409 if (!obj->rtld) { 1410 Needed_Entry *nep = NEW(Needed_Entry); 1411 nep->name = dynp->d_un.d_val; 1412 nep->obj = NULL; 1413 nep->next = NULL; 1414 1415 *needed_filtees_tail = nep; 1416 needed_filtees_tail = &nep->next; 1417 1418 if (obj->linkmap.l_refname == NULL) 1419 obj->linkmap.l_refname = (char *)dynp->d_un.d_val; 1420 } 1421 break; 1422 1423 case DT_AUXILIARY: 1424 if (!obj->rtld) { 1425 Needed_Entry *nep = NEW(Needed_Entry); 1426 nep->name = dynp->d_un.d_val; 1427 nep->obj = NULL; 1428 nep->next = NULL; 1429 1430 *needed_aux_filtees_tail = nep; 1431 needed_aux_filtees_tail = &nep->next; 1432 } 1433 break; 1434 1435 case DT_PLTGOT: 1436 obj->pltgot = (Elf_Addr *)(obj->relocbase + dynp->d_un.d_ptr); 1437 break; 1438 1439 case DT_TEXTREL: 1440 obj->textrel = true; 1441 break; 1442 1443 case DT_SYMBOLIC: 1444 obj->symbolic = true; 1445 break; 1446 1447 case DT_RPATH: 1448 /* 1449 * We have to wait until later to process this, because we 1450 * might not have gotten the address of the string table yet. 1451 */ 1452 *dyn_rpath = dynp; 1453 break; 1454 1455 case DT_SONAME: 1456 *dyn_soname = dynp; 1457 break; 1458 1459 case DT_RUNPATH: 1460 *dyn_runpath = dynp; 1461 break; 1462 1463 case DT_INIT: 1464 obj->init = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1465 break; 1466 1467 case DT_PREINIT_ARRAY: 1468 obj->preinit_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1469 break; 1470 1471 case DT_PREINIT_ARRAYSZ: 1472 obj->preinit_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1473 break; 1474 1475 case DT_INIT_ARRAY: 1476 obj->init_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1477 break; 1478 1479 case DT_INIT_ARRAYSZ: 1480 obj->init_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1481 break; 1482 1483 case DT_FINI: 1484 obj->fini = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1485 break; 1486 1487 case DT_FINI_ARRAY: 1488 obj->fini_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1489 break; 1490 1491 case DT_FINI_ARRAYSZ: 1492 obj->fini_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1493 break; 1494 1495 case DT_DEBUG: 1496 if (!early) 1497 dbg("Filling in DT_DEBUG entry"); 1498 (__DECONST(Elf_Dyn *, dynp))->d_un.d_ptr = (Elf_Addr)&r_debug; 1499 break; 1500 1501 case DT_FLAGS: 1502 if (dynp->d_un.d_val & DF_ORIGIN) 1503 obj->z_origin = true; 1504 if (dynp->d_un.d_val & DF_SYMBOLIC) 1505 obj->symbolic = true; 1506 if (dynp->d_un.d_val & DF_TEXTREL) 1507 obj->textrel = true; 1508 if (dynp->d_un.d_val & DF_BIND_NOW) 1509 obj->bind_now = true; 1510 if (dynp->d_un.d_val & DF_STATIC_TLS) 1511 obj->static_tls = true; 1512 break; 1513 1514 #ifdef __powerpc__ 1515 #ifdef __powerpc64__ 1516 case DT_PPC64_GLINK: 1517 obj->glink = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1518 break; 1519 #else 1520 case DT_PPC_GOT: 1521 obj->gotptr = (Elf_Addr *)(obj->relocbase + dynp->d_un.d_ptr); 1522 break; 1523 #endif 1524 #endif 1525 1526 case DT_FLAGS_1: 1527 if (dynp->d_un.d_val & DF_1_NOOPEN) 1528 obj->z_noopen = true; 1529 if (dynp->d_un.d_val & DF_1_ORIGIN) 1530 obj->z_origin = true; 1531 if (dynp->d_un.d_val & DF_1_GLOBAL) 1532 obj->z_global = true; 1533 if (dynp->d_un.d_val & DF_1_BIND_NOW) 1534 obj->bind_now = true; 1535 if (dynp->d_un.d_val & DF_1_NODELETE) 1536 obj->z_nodelete = true; 1537 if (dynp->d_un.d_val & DF_1_LOADFLTR) 1538 obj->z_loadfltr = true; 1539 if (dynp->d_un.d_val & DF_1_INTERPOSE) 1540 obj->z_interpose = true; 1541 if (dynp->d_un.d_val & DF_1_NODEFLIB) 1542 obj->z_nodeflib = true; 1543 if (dynp->d_un.d_val & DF_1_PIE) 1544 obj->z_pie = true; 1545 break; 1546 1547 default: 1548 if (!early) { 1549 dbg("Ignoring d_tag %ld = %#lx", (long)dynp->d_tag, 1550 (long)dynp->d_tag); 1551 } 1552 break; 1553 } 1554 } 1555 1556 obj->traced = false; 1557 1558 if (plttype == DT_RELA) { 1559 obj->pltrela = (const Elf_Rela *) obj->pltrel; 1560 obj->pltrel = NULL; 1561 obj->pltrelasize = obj->pltrelsize; 1562 obj->pltrelsize = 0; 1563 } 1564 1565 /* Determine size of dynsym table (equal to nchains of sysv hash) */ 1566 if (obj->valid_hash_sysv) 1567 obj->dynsymcount = obj->nchains; 1568 else if (obj->valid_hash_gnu) { 1569 obj->dynsymcount = 0; 1570 for (bkt = 0; bkt < obj->nbuckets_gnu; bkt++) { 1571 if (obj->buckets_gnu[bkt] == 0) 1572 continue; 1573 hashval = &obj->chain_zero_gnu[obj->buckets_gnu[bkt]]; 1574 do 1575 obj->dynsymcount++; 1576 while ((*hashval++ & 1u) == 0); 1577 } 1578 obj->dynsymcount += obj->symndx_gnu; 1579 } 1580 1581 if (obj->linkmap.l_refname != NULL) 1582 obj->linkmap.l_refname = obj->strtab + (unsigned long)obj-> 1583 linkmap.l_refname; 1584 } 1585 1586 static bool 1587 obj_resolve_origin(Obj_Entry *obj) 1588 { 1589 1590 if (obj->origin_path != NULL) 1591 return (true); 1592 obj->origin_path = xmalloc(PATH_MAX); 1593 return (rtld_dirname_abs(obj->path, obj->origin_path) != -1); 1594 } 1595 1596 static bool 1597 digest_dynamic2(Obj_Entry *obj, const Elf_Dyn *dyn_rpath, 1598 const Elf_Dyn *dyn_soname, const Elf_Dyn *dyn_runpath) 1599 { 1600 1601 if (obj->z_origin && !obj_resolve_origin(obj)) 1602 return (false); 1603 1604 if (dyn_runpath != NULL) { 1605 obj->runpath = (const char *)obj->strtab + dyn_runpath->d_un.d_val; 1606 obj->runpath = origin_subst(obj, obj->runpath); 1607 } else if (dyn_rpath != NULL) { 1608 obj->rpath = (const char *)obj->strtab + dyn_rpath->d_un.d_val; 1609 obj->rpath = origin_subst(obj, obj->rpath); 1610 } 1611 if (dyn_soname != NULL) 1612 object_add_name(obj, obj->strtab + dyn_soname->d_un.d_val); 1613 return (true); 1614 } 1615 1616 static bool 1617 digest_dynamic(Obj_Entry *obj, int early) 1618 { 1619 const Elf_Dyn *dyn_rpath; 1620 const Elf_Dyn *dyn_soname; 1621 const Elf_Dyn *dyn_runpath; 1622 1623 digest_dynamic1(obj, early, &dyn_rpath, &dyn_soname, &dyn_runpath); 1624 return (digest_dynamic2(obj, dyn_rpath, dyn_soname, dyn_runpath)); 1625 } 1626 1627 /* 1628 * Process a shared object's program header. This is used only for the 1629 * main program, when the kernel has already loaded the main program 1630 * into memory before calling the dynamic linker. It creates and 1631 * returns an Obj_Entry structure. 1632 */ 1633 static Obj_Entry * 1634 digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path) 1635 { 1636 Obj_Entry *obj; 1637 const Elf_Phdr *phlimit = phdr + phnum; 1638 const Elf_Phdr *ph; 1639 Elf_Addr note_start, note_end; 1640 int nsegs = 0; 1641 1642 obj = obj_new(); 1643 for (ph = phdr; ph < phlimit; ph++) { 1644 if (ph->p_type != PT_PHDR) 1645 continue; 1646 1647 obj->phdr = phdr; 1648 obj->phsize = ph->p_memsz; 1649 obj->relocbase = __DECONST(char *, phdr) - ph->p_vaddr; 1650 break; 1651 } 1652 1653 obj->stack_flags = PF_X | PF_R | PF_W; 1654 1655 for (ph = phdr; ph < phlimit; ph++) { 1656 switch (ph->p_type) { 1657 1658 case PT_INTERP: 1659 obj->interp = (const char *)(ph->p_vaddr + obj->relocbase); 1660 break; 1661 1662 case PT_LOAD: 1663 if (nsegs == 0) { /* First load segment */ 1664 obj->vaddrbase = rtld_trunc_page(ph->p_vaddr); 1665 obj->mapbase = obj->vaddrbase + obj->relocbase; 1666 } else { /* Last load segment */ 1667 obj->mapsize = rtld_round_page(ph->p_vaddr + ph->p_memsz) - 1668 obj->vaddrbase; 1669 } 1670 nsegs++; 1671 break; 1672 1673 case PT_DYNAMIC: 1674 obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + obj->relocbase); 1675 break; 1676 1677 case PT_TLS: 1678 obj->tlsindex = 1; 1679 obj->tlssize = ph->p_memsz; 1680 obj->tlsalign = ph->p_align; 1681 obj->tlsinitsize = ph->p_filesz; 1682 obj->tlsinit = (void*)(ph->p_vaddr + obj->relocbase); 1683 obj->tlspoffset = ph->p_offset; 1684 break; 1685 1686 case PT_GNU_STACK: 1687 obj->stack_flags = ph->p_flags; 1688 break; 1689 1690 case PT_GNU_RELRO: 1691 obj->relro_page = obj->relocbase + rtld_trunc_page(ph->p_vaddr); 1692 obj->relro_size = rtld_trunc_page(ph->p_vaddr + ph->p_memsz) - 1693 rtld_trunc_page(ph->p_vaddr); 1694 break; 1695 1696 case PT_NOTE: 1697 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; 1698 note_end = note_start + ph->p_filesz; 1699 digest_notes(obj, note_start, note_end); 1700 break; 1701 } 1702 } 1703 if (nsegs < 1) { 1704 _rtld_error("%s: too few PT_LOAD segments", path); 1705 return (NULL); 1706 } 1707 1708 obj->entry = entry; 1709 return (obj); 1710 } 1711 1712 void 1713 digest_notes(Obj_Entry *obj, Elf_Addr note_start, Elf_Addr note_end) 1714 { 1715 const Elf_Note *note; 1716 const char *note_name; 1717 uintptr_t p; 1718 1719 for (note = (const Elf_Note *)note_start; (Elf_Addr)note < note_end; 1720 note = (const Elf_Note *)((const char *)(note + 1) + 1721 roundup2(note->n_namesz, sizeof(Elf32_Addr)) + 1722 roundup2(note->n_descsz, sizeof(Elf32_Addr)))) { 1723 if (note->n_namesz != sizeof(NOTE_FREEBSD_VENDOR) || 1724 note->n_descsz != sizeof(int32_t)) 1725 continue; 1726 if (note->n_type != NT_FREEBSD_ABI_TAG && 1727 note->n_type != NT_FREEBSD_FEATURE_CTL && 1728 note->n_type != NT_FREEBSD_NOINIT_TAG) 1729 continue; 1730 note_name = (const char *)(note + 1); 1731 if (strncmp(NOTE_FREEBSD_VENDOR, note_name, 1732 sizeof(NOTE_FREEBSD_VENDOR)) != 0) 1733 continue; 1734 switch (note->n_type) { 1735 case NT_FREEBSD_ABI_TAG: 1736 /* FreeBSD osrel note */ 1737 p = (uintptr_t)(note + 1); 1738 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1739 obj->osrel = *(const int32_t *)(p); 1740 dbg("note osrel %d", obj->osrel); 1741 break; 1742 case NT_FREEBSD_FEATURE_CTL: 1743 /* FreeBSD ABI feature control note */ 1744 p = (uintptr_t)(note + 1); 1745 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1746 obj->fctl0 = *(const uint32_t *)(p); 1747 dbg("note fctl0 %#x", obj->fctl0); 1748 break; 1749 case NT_FREEBSD_NOINIT_TAG: 1750 /* FreeBSD 'crt does not call init' note */ 1751 obj->crt_no_init = true; 1752 dbg("note crt_no_init"); 1753 break; 1754 } 1755 } 1756 } 1757 1758 static Obj_Entry * 1759 dlcheck(void *handle) 1760 { 1761 Obj_Entry *obj; 1762 1763 TAILQ_FOREACH(obj, &obj_list, next) { 1764 if (obj == (Obj_Entry *) handle) 1765 break; 1766 } 1767 1768 if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) { 1769 _rtld_error("Invalid shared object handle %p", handle); 1770 return (NULL); 1771 } 1772 return (obj); 1773 } 1774 1775 /* 1776 * If the given object is already in the donelist, return true. Otherwise 1777 * add the object to the list and return false. 1778 */ 1779 static bool 1780 donelist_check(DoneList *dlp, const Obj_Entry *obj) 1781 { 1782 unsigned int i; 1783 1784 for (i = 0; i < dlp->num_used; i++) 1785 if (dlp->objs[i] == obj) 1786 return (true); 1787 /* 1788 * Our donelist allocation should always be sufficient. But if 1789 * our threads locking isn't working properly, more shared objects 1790 * could have been loaded since we allocated the list. That should 1791 * never happen, but we'll handle it properly just in case it does. 1792 */ 1793 if (dlp->num_used < dlp->num_alloc) 1794 dlp->objs[dlp->num_used++] = obj; 1795 return (false); 1796 } 1797 1798 /* 1799 * SysV hash function for symbol table lookup. It is a slightly optimized 1800 * version of the hash specified by the System V ABI. 1801 */ 1802 Elf32_Word 1803 elf_hash(const char *name) 1804 { 1805 const unsigned char *p = (const unsigned char *)name; 1806 Elf32_Word h = 0; 1807 1808 while (*p != '\0') { 1809 h = (h << 4) + *p++; 1810 h ^= (h >> 24) & 0xf0; 1811 } 1812 return (h & 0x0fffffff); 1813 } 1814 1815 /* 1816 * The GNU hash function is the Daniel J. Bernstein hash clipped to 32 bits 1817 * unsigned in case it's implemented with a wider type. 1818 */ 1819 static uint32_t 1820 gnu_hash(const char *s) 1821 { 1822 uint32_t h; 1823 unsigned char c; 1824 1825 h = 5381; 1826 for (c = *s; c != '\0'; c = *++s) 1827 h = h * 33 + c; 1828 return (h & 0xffffffff); 1829 } 1830 1831 1832 /* 1833 * Find the library with the given name, and return its full pathname. 1834 * The returned string is dynamically allocated. Generates an error 1835 * message and returns NULL if the library cannot be found. 1836 * 1837 * If the second argument is non-NULL, then it refers to an already- 1838 * loaded shared object, whose library search path will be searched. 1839 * 1840 * If a library is successfully located via LD_LIBRARY_PATH_FDS, its 1841 * descriptor (which is close-on-exec) will be passed out via the third 1842 * argument. 1843 * 1844 * The search order is: 1845 * DT_RPATH in the referencing file _unless_ DT_RUNPATH is present (1) 1846 * DT_RPATH of the main object if DSO without defined DT_RUNPATH (1) 1847 * LD_LIBRARY_PATH 1848 * DT_RUNPATH in the referencing file 1849 * ldconfig hints (if -z nodefaultlib, filter out default library directories 1850 * from list) 1851 * /lib:/usr/lib _unless_ the referencing file is linked with -z nodefaultlib 1852 * 1853 * (1) Handled in digest_dynamic2 - rpath left NULL if runpath defined. 1854 */ 1855 static char * 1856 find_library(const char *xname, const Obj_Entry *refobj, int *fdp) 1857 { 1858 char *pathname, *refobj_path; 1859 const char *name; 1860 bool nodeflib, objgiven; 1861 1862 objgiven = refobj != NULL; 1863 1864 if (libmap_disable || !objgiven || 1865 (name = lm_find(refobj->path, xname)) == NULL) 1866 name = xname; 1867 1868 if (strchr(name, '/') != NULL) { /* Hard coded pathname */ 1869 if (name[0] != '/' && !trust) { 1870 _rtld_error("Absolute pathname required " 1871 "for shared object \"%s\"", name); 1872 return (NULL); 1873 } 1874 return (origin_subst(__DECONST(Obj_Entry *, refobj), 1875 __DECONST(char *, name))); 1876 } 1877 1878 dbg(" Searching for \"%s\"", name); 1879 refobj_path = objgiven ? refobj->path : NULL; 1880 1881 /* 1882 * If refobj->rpath != NULL, then refobj->runpath is NULL. Fall 1883 * back to pre-conforming behaviour if user requested so with 1884 * LD_LIBRARY_PATH_RPATH environment variable and ignore -z 1885 * nodeflib. 1886 */ 1887 if (objgiven && refobj->rpath != NULL && ld_library_path_rpath) { 1888 pathname = search_library_path(name, ld_library_path, 1889 refobj_path, fdp); 1890 if (pathname != NULL) 1891 return (pathname); 1892 if (refobj != NULL) { 1893 pathname = search_library_path(name, refobj->rpath, 1894 refobj_path, fdp); 1895 if (pathname != NULL) 1896 return (pathname); 1897 } 1898 pathname = search_library_pathfds(name, ld_library_dirs, fdp); 1899 if (pathname != NULL) 1900 return (pathname); 1901 pathname = search_library_path(name, gethints(false), 1902 refobj_path, fdp); 1903 if (pathname != NULL) 1904 return (pathname); 1905 pathname = search_library_path(name, ld_standard_library_path, 1906 refobj_path, fdp); 1907 if (pathname != NULL) 1908 return (pathname); 1909 } else { 1910 nodeflib = objgiven ? refobj->z_nodeflib : false; 1911 if (objgiven) { 1912 pathname = search_library_path(name, refobj->rpath, 1913 refobj->path, fdp); 1914 if (pathname != NULL) 1915 return (pathname); 1916 } 1917 if (objgiven && refobj->runpath == NULL && refobj != obj_main) { 1918 pathname = search_library_path(name, obj_main->rpath, 1919 refobj_path, fdp); 1920 if (pathname != NULL) 1921 return (pathname); 1922 } 1923 pathname = search_library_path(name, ld_library_path, 1924 refobj_path, fdp); 1925 if (pathname != NULL) 1926 return (pathname); 1927 if (objgiven) { 1928 pathname = search_library_path(name, refobj->runpath, 1929 refobj_path, fdp); 1930 if (pathname != NULL) 1931 return (pathname); 1932 } 1933 pathname = search_library_pathfds(name, ld_library_dirs, fdp); 1934 if (pathname != NULL) 1935 return (pathname); 1936 pathname = search_library_path(name, gethints(nodeflib), 1937 refobj_path, fdp); 1938 if (pathname != NULL) 1939 return (pathname); 1940 if (objgiven && !nodeflib) { 1941 pathname = search_library_path(name, 1942 ld_standard_library_path, refobj_path, fdp); 1943 if (pathname != NULL) 1944 return (pathname); 1945 } 1946 } 1947 1948 if (objgiven && refobj->path != NULL) { 1949 _rtld_error("Shared object \"%s\" not found, " 1950 "required by \"%s\"", name, basename(refobj->path)); 1951 } else { 1952 _rtld_error("Shared object \"%s\" not found", name); 1953 } 1954 return (NULL); 1955 } 1956 1957 /* 1958 * Given a symbol number in a referencing object, find the corresponding 1959 * definition of the symbol. Returns a pointer to the symbol, or NULL if 1960 * no definition was found. Returns a pointer to the Obj_Entry of the 1961 * defining object via the reference parameter DEFOBJ_OUT. 1962 */ 1963 const Elf_Sym * 1964 find_symdef(unsigned long symnum, const Obj_Entry *refobj, 1965 const Obj_Entry **defobj_out, int flags, SymCache *cache, 1966 RtldLockState *lockstate) 1967 { 1968 const Elf_Sym *ref; 1969 const Elf_Sym *def; 1970 const Obj_Entry *defobj; 1971 const Ver_Entry *ve; 1972 SymLook req; 1973 const char *name; 1974 int res; 1975 1976 /* 1977 * If we have already found this symbol, get the information from 1978 * the cache. 1979 */ 1980 if (symnum >= refobj->dynsymcount) 1981 return (NULL); /* Bad object */ 1982 if (cache != NULL && cache[symnum].sym != NULL) { 1983 *defobj_out = cache[symnum].obj; 1984 return (cache[symnum].sym); 1985 } 1986 1987 ref = refobj->symtab + symnum; 1988 name = refobj->strtab + ref->st_name; 1989 def = NULL; 1990 defobj = NULL; 1991 ve = NULL; 1992 1993 /* 1994 * We don't have to do a full scale lookup if the symbol is local. 1995 * We know it will bind to the instance in this load module; to 1996 * which we already have a pointer (ie ref). By not doing a lookup, 1997 * we not only improve performance, but it also avoids unresolvable 1998 * symbols when local symbols are not in the hash table. This has 1999 * been seen with the ia64 toolchain. 2000 */ 2001 if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) { 2002 if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) { 2003 _rtld_error("%s: Bogus symbol table entry %lu", refobj->path, 2004 symnum); 2005 } 2006 symlook_init(&req, name); 2007 req.flags = flags; 2008 ve = req.ventry = fetch_ventry(refobj, symnum); 2009 req.lockstate = lockstate; 2010 res = symlook_default(&req, refobj); 2011 if (res == 0) { 2012 def = req.sym_out; 2013 defobj = req.defobj_out; 2014 } 2015 } else { 2016 def = ref; 2017 defobj = refobj; 2018 } 2019 2020 /* 2021 * If we found no definition and the reference is weak, treat the 2022 * symbol as having the value zero. 2023 */ 2024 if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) { 2025 def = &sym_zero; 2026 defobj = obj_main; 2027 } 2028 2029 if (def != NULL) { 2030 *defobj_out = defobj; 2031 /* Record the information in the cache to avoid subsequent lookups. */ 2032 if (cache != NULL) { 2033 cache[symnum].sym = def; 2034 cache[symnum].obj = defobj; 2035 } 2036 } else { 2037 if (refobj != &obj_rtld) 2038 _rtld_error("%s: Undefined symbol \"%s%s%s\"", refobj->path, name, 2039 ve != NULL ? "@" : "", ve != NULL ? ve->name : ""); 2040 } 2041 return (def); 2042 } 2043 2044 /* 2045 * Return the search path from the ldconfig hints file, reading it if 2046 * necessary. If nostdlib is true, then the default search paths are 2047 * not added to result. 2048 * 2049 * Returns NULL if there are problems with the hints file, 2050 * or if the search path there is empty. 2051 */ 2052 static const char * 2053 gethints(bool nostdlib) 2054 { 2055 static char *filtered_path; 2056 static const char *hints; 2057 static struct elfhints_hdr hdr; 2058 struct fill_search_info_args sargs, hargs; 2059 struct dl_serinfo smeta, hmeta, *SLPinfo, *hintinfo; 2060 struct dl_serpath *SLPpath, *hintpath; 2061 char *p; 2062 struct stat hint_stat; 2063 unsigned int SLPndx, hintndx, fndx, fcount; 2064 int fd; 2065 size_t flen; 2066 uint32_t dl; 2067 bool skip; 2068 2069 /* First call, read the hints file */ 2070 if (hints == NULL) { 2071 /* Keep from trying again in case the hints file is bad. */ 2072 hints = ""; 2073 2074 if ((fd = open(ld_elf_hints_path, O_RDONLY | O_CLOEXEC)) == -1) 2075 return (NULL); 2076 2077 /* 2078 * Check of hdr.dirlistlen value against type limit 2079 * intends to pacify static analyzers. Further 2080 * paranoia leads to checks that dirlist is fully 2081 * contained in the file range. 2082 */ 2083 if (read(fd, &hdr, sizeof hdr) != sizeof hdr || 2084 hdr.magic != ELFHINTS_MAGIC || 2085 hdr.version != 1 || hdr.dirlistlen > UINT_MAX / 2 || 2086 fstat(fd, &hint_stat) == -1) { 2087 cleanup1: 2088 close(fd); 2089 hdr.dirlistlen = 0; 2090 return (NULL); 2091 } 2092 dl = hdr.strtab; 2093 if (dl + hdr.dirlist < dl) 2094 goto cleanup1; 2095 dl += hdr.dirlist; 2096 if (dl + hdr.dirlistlen < dl) 2097 goto cleanup1; 2098 dl += hdr.dirlistlen; 2099 if (dl > hint_stat.st_size) 2100 goto cleanup1; 2101 p = xmalloc(hdr.dirlistlen + 1); 2102 if (pread(fd, p, hdr.dirlistlen + 1, 2103 hdr.strtab + hdr.dirlist) != (ssize_t)hdr.dirlistlen + 1 || 2104 p[hdr.dirlistlen] != '\0') { 2105 free(p); 2106 goto cleanup1; 2107 } 2108 hints = p; 2109 close(fd); 2110 } 2111 2112 /* 2113 * If caller agreed to receive list which includes the default 2114 * paths, we are done. Otherwise, if we still did not 2115 * calculated filtered result, do it now. 2116 */ 2117 if (!nostdlib) 2118 return (hints[0] != '\0' ? hints : NULL); 2119 if (filtered_path != NULL) 2120 goto filt_ret; 2121 2122 /* 2123 * Obtain the list of all configured search paths, and the 2124 * list of the default paths. 2125 * 2126 * First estimate the size of the results. 2127 */ 2128 smeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 2129 smeta.dls_cnt = 0; 2130 hmeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 2131 hmeta.dls_cnt = 0; 2132 2133 sargs.request = RTLD_DI_SERINFOSIZE; 2134 sargs.serinfo = &smeta; 2135 hargs.request = RTLD_DI_SERINFOSIZE; 2136 hargs.serinfo = &hmeta; 2137 2138 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 2139 &sargs); 2140 path_enumerate(hints, fill_search_info, NULL, &hargs); 2141 2142 SLPinfo = xmalloc(smeta.dls_size); 2143 hintinfo = xmalloc(hmeta.dls_size); 2144 2145 /* 2146 * Next fetch both sets of paths. 2147 */ 2148 sargs.request = RTLD_DI_SERINFO; 2149 sargs.serinfo = SLPinfo; 2150 sargs.serpath = &SLPinfo->dls_serpath[0]; 2151 sargs.strspace = (char *)&SLPinfo->dls_serpath[smeta.dls_cnt]; 2152 2153 hargs.request = RTLD_DI_SERINFO; 2154 hargs.serinfo = hintinfo; 2155 hargs.serpath = &hintinfo->dls_serpath[0]; 2156 hargs.strspace = (char *)&hintinfo->dls_serpath[hmeta.dls_cnt]; 2157 2158 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 2159 &sargs); 2160 path_enumerate(hints, fill_search_info, NULL, &hargs); 2161 2162 /* 2163 * Now calculate the difference between two sets, by excluding 2164 * standard paths from the full set. 2165 */ 2166 fndx = 0; 2167 fcount = 0; 2168 filtered_path = xmalloc(hdr.dirlistlen + 1); 2169 hintpath = &hintinfo->dls_serpath[0]; 2170 for (hintndx = 0; hintndx < hmeta.dls_cnt; hintndx++, hintpath++) { 2171 skip = false; 2172 SLPpath = &SLPinfo->dls_serpath[0]; 2173 /* 2174 * Check each standard path against current. 2175 */ 2176 for (SLPndx = 0; SLPndx < smeta.dls_cnt; SLPndx++, SLPpath++) { 2177 /* matched, skip the path */ 2178 if (!strcmp(hintpath->dls_name, SLPpath->dls_name)) { 2179 skip = true; 2180 break; 2181 } 2182 } 2183 if (skip) 2184 continue; 2185 /* 2186 * Not matched against any standard path, add the path 2187 * to result. Separate consequtive paths with ':'. 2188 */ 2189 if (fcount > 0) { 2190 filtered_path[fndx] = ':'; 2191 fndx++; 2192 } 2193 fcount++; 2194 flen = strlen(hintpath->dls_name); 2195 strncpy((filtered_path + fndx), hintpath->dls_name, flen); 2196 fndx += flen; 2197 } 2198 filtered_path[fndx] = '\0'; 2199 2200 free(SLPinfo); 2201 free(hintinfo); 2202 2203 filt_ret: 2204 return (filtered_path[0] != '\0' ? filtered_path : NULL); 2205 } 2206 2207 static void 2208 init_dag(Obj_Entry *root) 2209 { 2210 const Needed_Entry *needed; 2211 const Objlist_Entry *elm; 2212 DoneList donelist; 2213 2214 if (root->dag_inited) 2215 return; 2216 donelist_init(&donelist); 2217 2218 /* Root object belongs to own DAG. */ 2219 objlist_push_tail(&root->dldags, root); 2220 objlist_push_tail(&root->dagmembers, root); 2221 donelist_check(&donelist, root); 2222 2223 /* 2224 * Add dependencies of root object to DAG in breadth order 2225 * by exploiting the fact that each new object get added 2226 * to the tail of the dagmembers list. 2227 */ 2228 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2229 for (needed = elm->obj->needed; needed != NULL; needed = needed->next) { 2230 if (needed->obj == NULL || donelist_check(&donelist, needed->obj)) 2231 continue; 2232 objlist_push_tail(&needed->obj->dldags, root); 2233 objlist_push_tail(&root->dagmembers, needed->obj); 2234 } 2235 } 2236 root->dag_inited = true; 2237 } 2238 2239 static void 2240 init_marker(Obj_Entry *marker) 2241 { 2242 2243 bzero(marker, sizeof(*marker)); 2244 marker->marker = true; 2245 } 2246 2247 Obj_Entry * 2248 globallist_curr(const Obj_Entry *obj) 2249 { 2250 2251 for (;;) { 2252 if (obj == NULL) 2253 return (NULL); 2254 if (!obj->marker) 2255 return (__DECONST(Obj_Entry *, obj)); 2256 obj = TAILQ_PREV(obj, obj_entry_q, next); 2257 } 2258 } 2259 2260 Obj_Entry * 2261 globallist_next(const Obj_Entry *obj) 2262 { 2263 2264 for (;;) { 2265 obj = TAILQ_NEXT(obj, next); 2266 if (obj == NULL) 2267 return (NULL); 2268 if (!obj->marker) 2269 return (__DECONST(Obj_Entry *, obj)); 2270 } 2271 } 2272 2273 /* Prevent the object from being unmapped while the bind lock is dropped. */ 2274 static void 2275 hold_object(Obj_Entry *obj) 2276 { 2277 2278 obj->holdcount++; 2279 } 2280 2281 static void 2282 unhold_object(Obj_Entry *obj) 2283 { 2284 2285 assert(obj->holdcount > 0); 2286 if (--obj->holdcount == 0 && obj->unholdfree) 2287 release_object(obj); 2288 } 2289 2290 static void 2291 process_z(Obj_Entry *root) 2292 { 2293 const Objlist_Entry *elm; 2294 Obj_Entry *obj; 2295 2296 /* 2297 * Walk over object DAG and process every dependent object 2298 * that is marked as DF_1_NODELETE or DF_1_GLOBAL. They need 2299 * to grow their own DAG. 2300 * 2301 * For DF_1_GLOBAL, DAG is required for symbol lookups in 2302 * symlook_global() to work. 2303 * 2304 * For DF_1_NODELETE, the DAG should have its reference upped. 2305 */ 2306 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2307 obj = elm->obj; 2308 if (obj == NULL) 2309 continue; 2310 if (obj->z_nodelete && !obj->ref_nodel) { 2311 dbg("obj %s -z nodelete", obj->path); 2312 init_dag(obj); 2313 ref_dag(obj); 2314 obj->ref_nodel = true; 2315 } 2316 if (obj->z_global && objlist_find(&list_global, obj) == NULL) { 2317 dbg("obj %s -z global", obj->path); 2318 objlist_push_tail(&list_global, obj); 2319 init_dag(obj); 2320 } 2321 } 2322 } 2323 2324 static void 2325 parse_rtld_phdr(Obj_Entry *obj) 2326 { 2327 const Elf_Phdr *ph; 2328 Elf_Addr note_start, note_end; 2329 2330 obj->stack_flags = PF_X | PF_R | PF_W; 2331 for (ph = obj->phdr; (const char *)ph < (const char *)obj->phdr + 2332 obj->phsize; ph++) { 2333 switch (ph->p_type) { 2334 case PT_GNU_STACK: 2335 obj->stack_flags = ph->p_flags; 2336 break; 2337 case PT_GNU_RELRO: 2338 obj->relro_page = obj->relocbase + 2339 rtld_trunc_page(ph->p_vaddr); 2340 obj->relro_size = rtld_round_page(ph->p_memsz); 2341 break; 2342 case PT_NOTE: 2343 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; 2344 note_end = note_start + ph->p_filesz; 2345 digest_notes(obj, note_start, note_end); 2346 break; 2347 } 2348 } 2349 } 2350 2351 /* 2352 * Initialize the dynamic linker. The argument is the address at which 2353 * the dynamic linker has been mapped into memory. The primary task of 2354 * this function is to relocate the dynamic linker. 2355 */ 2356 static void 2357 init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info) 2358 { 2359 Obj_Entry objtmp; /* Temporary rtld object */ 2360 const Elf_Ehdr *ehdr; 2361 const Elf_Dyn *dyn_rpath; 2362 const Elf_Dyn *dyn_soname; 2363 const Elf_Dyn *dyn_runpath; 2364 2365 #ifdef RTLD_INIT_PAGESIZES_EARLY 2366 /* The page size is required by the dynamic memory allocator. */ 2367 init_pagesizes(aux_info); 2368 #endif 2369 2370 /* 2371 * Conjure up an Obj_Entry structure for the dynamic linker. 2372 * 2373 * The "path" member can't be initialized yet because string constants 2374 * cannot yet be accessed. Below we will set it correctly. 2375 */ 2376 memset(&objtmp, 0, sizeof(objtmp)); 2377 objtmp.path = NULL; 2378 objtmp.rtld = true; 2379 objtmp.mapbase = mapbase; 2380 #ifdef PIC 2381 objtmp.relocbase = mapbase; 2382 #endif 2383 2384 objtmp.dynamic = rtld_dynamic(&objtmp); 2385 digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname, &dyn_runpath); 2386 assert(objtmp.needed == NULL); 2387 assert(!objtmp.textrel); 2388 /* 2389 * Temporarily put the dynamic linker entry into the object list, so 2390 * that symbols can be found. 2391 */ 2392 relocate_objects(&objtmp, true, &objtmp, 0, NULL); 2393 2394 ehdr = (Elf_Ehdr *)mapbase; 2395 objtmp.phdr = (Elf_Phdr *)((char *)mapbase + ehdr->e_phoff); 2396 objtmp.phsize = ehdr->e_phnum * sizeof(objtmp.phdr[0]); 2397 2398 /* Initialize the object list. */ 2399 TAILQ_INIT(&obj_list); 2400 2401 /* Now that non-local variables can be accesses, copy out obj_rtld. */ 2402 memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld)); 2403 2404 #ifndef RTLD_INIT_PAGESIZES_EARLY 2405 /* The page size is required by the dynamic memory allocator. */ 2406 init_pagesizes(aux_info); 2407 #endif 2408 2409 if (aux_info[AT_OSRELDATE] != NULL) 2410 osreldate = aux_info[AT_OSRELDATE]->a_un.a_val; 2411 2412 digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname, dyn_runpath); 2413 2414 /* Replace the path with a dynamically allocated copy. */ 2415 obj_rtld.path = xstrdup(ld_path_rtld); 2416 2417 parse_rtld_phdr(&obj_rtld); 2418 if (obj_enforce_relro(&obj_rtld) == -1) 2419 rtld_die(); 2420 2421 r_debug.r_version = R_DEBUG_VERSION; 2422 r_debug.r_brk = r_debug_state; 2423 r_debug.r_state = RT_CONSISTENT; 2424 r_debug.r_ldbase = obj_rtld.relocbase; 2425 } 2426 2427 /* 2428 * Retrieve the array of supported page sizes. The kernel provides the page 2429 * sizes in increasing order. 2430 */ 2431 static void 2432 init_pagesizes(Elf_Auxinfo **aux_info) 2433 { 2434 static size_t psa[MAXPAGESIZES]; 2435 int mib[2]; 2436 size_t len, size; 2437 2438 if (aux_info[AT_PAGESIZES] != NULL && aux_info[AT_PAGESIZESLEN] != 2439 NULL) { 2440 size = aux_info[AT_PAGESIZESLEN]->a_un.a_val; 2441 pagesizes = aux_info[AT_PAGESIZES]->a_un.a_ptr; 2442 } else { 2443 len = 2; 2444 if (sysctlnametomib("hw.pagesizes", mib, &len) == 0) 2445 size = sizeof(psa); 2446 else { 2447 /* As a fallback, retrieve the base page size. */ 2448 size = sizeof(psa[0]); 2449 if (aux_info[AT_PAGESZ] != NULL) { 2450 psa[0] = aux_info[AT_PAGESZ]->a_un.a_val; 2451 goto psa_filled; 2452 } else { 2453 mib[0] = CTL_HW; 2454 mib[1] = HW_PAGESIZE; 2455 len = 2; 2456 } 2457 } 2458 if (sysctl(mib, len, psa, &size, NULL, 0) == -1) { 2459 _rtld_error("sysctl for hw.pagesize(s) failed"); 2460 rtld_die(); 2461 } 2462 psa_filled: 2463 pagesizes = psa; 2464 } 2465 npagesizes = size / sizeof(pagesizes[0]); 2466 /* Discard any invalid entries at the end of the array. */ 2467 while (npagesizes > 0 && pagesizes[npagesizes - 1] == 0) 2468 npagesizes--; 2469 2470 page_size = pagesizes[0]; 2471 } 2472 2473 /* 2474 * Add the init functions from a needed object list (and its recursive 2475 * needed objects) to "list". This is not used directly; it is a helper 2476 * function for initlist_add_objects(). The write lock must be held 2477 * when this function is called. 2478 */ 2479 static void 2480 initlist_add_neededs(Needed_Entry *needed, Objlist *list) 2481 { 2482 /* Recursively process the successor needed objects. */ 2483 if (needed->next != NULL) 2484 initlist_add_neededs(needed->next, list); 2485 2486 /* Process the current needed object. */ 2487 if (needed->obj != NULL) 2488 initlist_add_objects(needed->obj, needed->obj, list); 2489 } 2490 2491 /* 2492 * Scan all of the DAGs rooted in the range of objects from "obj" to 2493 * "tail" and add their init functions to "list". This recurses over 2494 * the DAGs and ensure the proper init ordering such that each object's 2495 * needed libraries are initialized before the object itself. At the 2496 * same time, this function adds the objects to the global finalization 2497 * list "list_fini" in the opposite order. The write lock must be 2498 * held when this function is called. 2499 */ 2500 static void 2501 initlist_add_objects(Obj_Entry *obj, Obj_Entry *tail, Objlist *list) 2502 { 2503 Obj_Entry *nobj; 2504 2505 if (obj->init_scanned || obj->init_done) 2506 return; 2507 obj->init_scanned = true; 2508 2509 /* Recursively process the successor objects. */ 2510 nobj = globallist_next(obj); 2511 if (nobj != NULL && obj != tail) 2512 initlist_add_objects(nobj, tail, list); 2513 2514 /* Recursively process the needed objects. */ 2515 if (obj->needed != NULL) 2516 initlist_add_neededs(obj->needed, list); 2517 if (obj->needed_filtees != NULL) 2518 initlist_add_neededs(obj->needed_filtees, list); 2519 if (obj->needed_aux_filtees != NULL) 2520 initlist_add_neededs(obj->needed_aux_filtees, list); 2521 2522 /* Add the object to the init list. */ 2523 objlist_push_tail(list, obj); 2524 2525 /* Add the object to the global fini list in the reverse order. */ 2526 if ((obj->fini != (Elf_Addr)NULL || obj->fini_array != (Elf_Addr)NULL) 2527 && !obj->on_fini_list) { 2528 objlist_push_head(&list_fini, obj); 2529 obj->on_fini_list = true; 2530 } 2531 } 2532 2533 static void 2534 free_needed_filtees(Needed_Entry *n, RtldLockState *lockstate) 2535 { 2536 Needed_Entry *needed, *needed1; 2537 2538 for (needed = n; needed != NULL; needed = needed->next) { 2539 if (needed->obj != NULL) { 2540 dlclose_locked(needed->obj, lockstate); 2541 needed->obj = NULL; 2542 } 2543 } 2544 for (needed = n; needed != NULL; needed = needed1) { 2545 needed1 = needed->next; 2546 free(needed); 2547 } 2548 } 2549 2550 static void 2551 unload_filtees(Obj_Entry *obj, RtldLockState *lockstate) 2552 { 2553 2554 free_needed_filtees(obj->needed_filtees, lockstate); 2555 obj->needed_filtees = NULL; 2556 free_needed_filtees(obj->needed_aux_filtees, lockstate); 2557 obj->needed_aux_filtees = NULL; 2558 obj->filtees_loaded = false; 2559 } 2560 2561 static void 2562 load_filtee1(Obj_Entry *obj, Needed_Entry *needed, int flags, 2563 RtldLockState *lockstate) 2564 { 2565 2566 for (; needed != NULL; needed = needed->next) { 2567 needed->obj = dlopen_object(obj->strtab + needed->name, -1, obj, 2568 flags, ((ld_loadfltr || obj->z_loadfltr) ? RTLD_NOW : RTLD_LAZY) | 2569 RTLD_LOCAL, lockstate); 2570 } 2571 } 2572 2573 static void 2574 load_filtees(Obj_Entry *obj, int flags, RtldLockState *lockstate) 2575 { 2576 2577 lock_restart_for_upgrade(lockstate); 2578 if (!obj->filtees_loaded) { 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 } 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 && name != NULL) { 2746 object_add_name(obj, name); 2747 free(path); 2748 close(fd); 2749 return (obj); 2750 } 2751 if (flags & RTLD_LO_NOLOAD) { 2752 free(path); 2753 close(fd); 2754 return (NULL); 2755 } 2756 2757 /* First use of this object, so we must map it in */ 2758 obj = do_load_object(fd, name, path, &sb, flags); 2759 if (obj == NULL) 2760 free(path); 2761 close(fd); 2762 2763 return (obj); 2764 } 2765 2766 static Obj_Entry * 2767 do_load_object(int fd, const char *name, char *path, struct stat *sbp, 2768 int flags) 2769 { 2770 Obj_Entry *obj; 2771 struct statfs fs; 2772 2773 /* 2774 * First, make sure that environment variables haven't been 2775 * used to circumvent the noexec flag on a filesystem. 2776 * We ignore fstatfs(2) failures, since fd might reference 2777 * not a file, e.g. shmfd. 2778 */ 2779 if (dangerous_ld_env && fstatfs(fd, &fs) == 0 && 2780 (fs.f_flags & MNT_NOEXEC) != 0) { 2781 _rtld_error("Cannot execute objects on %s", fs.f_mntonname); 2782 return (NULL); 2783 } 2784 2785 dbg("loading \"%s\"", printable_path(path)); 2786 obj = map_object(fd, printable_path(path), sbp); 2787 if (obj == NULL) 2788 return (NULL); 2789 2790 /* 2791 * If DT_SONAME is present in the object, digest_dynamic2 already 2792 * added it to the object names. 2793 */ 2794 if (name != NULL) 2795 object_add_name(obj, name); 2796 obj->path = path; 2797 if (!digest_dynamic(obj, 0)) 2798 goto errp; 2799 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", obj->path, 2800 obj->valid_hash_sysv, obj->valid_hash_gnu, obj->dynsymcount); 2801 if (obj->z_pie && (flags & RTLD_LO_TRACE) == 0) { 2802 dbg("refusing to load PIE executable \"%s\"", obj->path); 2803 _rtld_error("Cannot load PIE binary %s as DSO", obj->path); 2804 goto errp; 2805 } 2806 if (obj->z_noopen && (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) == 2807 RTLD_LO_DLOPEN) { 2808 dbg("refusing to load non-loadable \"%s\"", obj->path); 2809 _rtld_error("Cannot dlopen non-loadable %s", obj->path); 2810 goto errp; 2811 } 2812 2813 obj->dlopened = (flags & RTLD_LO_DLOPEN) != 0; 2814 TAILQ_INSERT_TAIL(&obj_list, obj, next); 2815 obj_count++; 2816 obj_loads++; 2817 linkmap_add(obj); /* for GDB & dlinfo() */ 2818 max_stack_flags |= obj->stack_flags; 2819 2820 dbg(" %p .. %p: %s", obj->mapbase, 2821 obj->mapbase + obj->mapsize - 1, obj->path); 2822 if (obj->textrel) 2823 dbg(" WARNING: %s has impure text", obj->path); 2824 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 2825 obj->path); 2826 2827 return (obj); 2828 2829 errp: 2830 munmap(obj->mapbase, obj->mapsize); 2831 obj_free(obj); 2832 return (NULL); 2833 } 2834 2835 static int 2836 load_kpreload(const void *addr) 2837 { 2838 Obj_Entry *obj; 2839 const Elf_Ehdr *ehdr; 2840 const Elf_Phdr *phdr, *phlimit, *phdyn, *seg0, *segn; 2841 static const char kname[] = "[vdso]"; 2842 2843 ehdr = addr; 2844 if (!check_elf_headers(ehdr, "kpreload")) 2845 return (-1); 2846 obj = obj_new(); 2847 phdr = (const Elf_Phdr *)((const char *)addr + ehdr->e_phoff); 2848 obj->phdr = phdr; 2849 obj->phsize = ehdr->e_phnum * sizeof(*phdr); 2850 phlimit = phdr + ehdr->e_phnum; 2851 seg0 = segn = NULL; 2852 2853 for (; phdr < phlimit; phdr++) { 2854 switch (phdr->p_type) { 2855 case PT_DYNAMIC: 2856 phdyn = phdr; 2857 break; 2858 case PT_GNU_STACK: 2859 /* Absense of PT_GNU_STACK implies stack_flags == 0. */ 2860 obj->stack_flags = phdr->p_flags; 2861 break; 2862 case PT_LOAD: 2863 if (seg0 == NULL || seg0->p_vaddr > phdr->p_vaddr) 2864 seg0 = phdr; 2865 if (segn == NULL || segn->p_vaddr + segn->p_memsz < 2866 phdr->p_vaddr + phdr->p_memsz) 2867 segn = phdr; 2868 break; 2869 } 2870 } 2871 2872 obj->mapbase = __DECONST(caddr_t, addr); 2873 obj->mapsize = segn->p_vaddr + segn->p_memsz - (Elf_Addr)addr; 2874 obj->vaddrbase = 0; 2875 obj->relocbase = obj->mapbase; 2876 2877 object_add_name(obj, kname); 2878 obj->path = xstrdup(kname); 2879 obj->dynamic = (const Elf_Dyn *)(obj->relocbase + phdyn->p_vaddr); 2880 2881 if (!digest_dynamic(obj, 0)) { 2882 obj_free(obj); 2883 return (-1); 2884 } 2885 2886 /* 2887 * We assume that kernel-preloaded object does not need 2888 * relocation. It is currently written into read-only page, 2889 * handling relocations would mean we need to allocate at 2890 * least one additional page per AS. 2891 */ 2892 dbg("%s mapbase %p phdrs %p PT_LOAD phdr %p vaddr %p dynamic %p", 2893 obj->path, obj->mapbase, obj->phdr, seg0, 2894 obj->relocbase + seg0->p_vaddr, obj->dynamic); 2895 2896 TAILQ_INSERT_TAIL(&obj_list, obj, next); 2897 obj_count++; 2898 obj_loads++; 2899 linkmap_add(obj); /* for GDB & dlinfo() */ 2900 max_stack_flags |= obj->stack_flags; 2901 2902 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, 0, 0, obj->path); 2903 return (0); 2904 } 2905 2906 Obj_Entry * 2907 obj_from_addr(const void *addr) 2908 { 2909 Obj_Entry *obj; 2910 2911 TAILQ_FOREACH(obj, &obj_list, next) { 2912 if (obj->marker) 2913 continue; 2914 if (addr < (void *) obj->mapbase) 2915 continue; 2916 if (addr < (void *)(obj->mapbase + obj->mapsize)) 2917 return obj; 2918 } 2919 return (NULL); 2920 } 2921 2922 static void 2923 preinit_main(void) 2924 { 2925 Elf_Addr *preinit_addr; 2926 int index; 2927 2928 preinit_addr = (Elf_Addr *)obj_main->preinit_array; 2929 if (preinit_addr == NULL) 2930 return; 2931 2932 for (index = 0; index < obj_main->preinit_array_num; index++) { 2933 if (preinit_addr[index] != 0 && preinit_addr[index] != 1) { 2934 dbg("calling preinit function for %s at %p", obj_main->path, 2935 (void *)preinit_addr[index]); 2936 LD_UTRACE(UTRACE_INIT_CALL, obj_main, (void *)preinit_addr[index], 2937 0, 0, obj_main->path); 2938 call_init_pointer(obj_main, preinit_addr[index]); 2939 } 2940 } 2941 } 2942 2943 /* 2944 * Call the finalization functions for each of the objects in "list" 2945 * belonging to the DAG of "root" and referenced once. If NULL "root" 2946 * is specified, every finalization function will be called regardless 2947 * of the reference count and the list elements won't be freed. All of 2948 * the objects are expected to have non-NULL fini functions. 2949 */ 2950 static void 2951 objlist_call_fini(Objlist *list, Obj_Entry *root, RtldLockState *lockstate) 2952 { 2953 Objlist_Entry *elm; 2954 struct dlerror_save *saved_msg; 2955 Elf_Addr *fini_addr; 2956 int index; 2957 2958 assert(root == NULL || root->refcount == 1); 2959 2960 if (root != NULL) 2961 root->doomed = true; 2962 2963 /* 2964 * Preserve the current error message since a fini function might 2965 * call into the dynamic linker and overwrite it. 2966 */ 2967 saved_msg = errmsg_save(); 2968 do { 2969 STAILQ_FOREACH(elm, list, link) { 2970 if (root != NULL && (elm->obj->refcount != 1 || 2971 objlist_find(&root->dagmembers, elm->obj) == NULL)) 2972 continue; 2973 /* Remove object from fini list to prevent recursive invocation. */ 2974 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 2975 /* Ensure that new references cannot be acquired. */ 2976 elm->obj->doomed = true; 2977 2978 hold_object(elm->obj); 2979 lock_release(rtld_bind_lock, lockstate); 2980 /* 2981 * It is legal to have both DT_FINI and DT_FINI_ARRAY defined. 2982 * When this happens, DT_FINI_ARRAY is processed first. 2983 */ 2984 fini_addr = (Elf_Addr *)elm->obj->fini_array; 2985 if (fini_addr != NULL && elm->obj->fini_array_num > 0) { 2986 for (index = elm->obj->fini_array_num - 1; index >= 0; 2987 index--) { 2988 if (fini_addr[index] != 0 && fini_addr[index] != 1) { 2989 dbg("calling fini function for %s at %p", 2990 elm->obj->path, (void *)fini_addr[index]); 2991 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, 2992 (void *)fini_addr[index], 0, 0, elm->obj->path); 2993 call_initfini_pointer(elm->obj, fini_addr[index]); 2994 } 2995 } 2996 } 2997 if (elm->obj->fini != (Elf_Addr)NULL) { 2998 dbg("calling fini function for %s at %p", elm->obj->path, 2999 (void *)elm->obj->fini); 3000 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, (void *)elm->obj->fini, 3001 0, 0, elm->obj->path); 3002 call_initfini_pointer(elm->obj, elm->obj->fini); 3003 } 3004 wlock_acquire(rtld_bind_lock, lockstate); 3005 unhold_object(elm->obj); 3006 /* No need to free anything if process is going down. */ 3007 if (root != NULL) 3008 free(elm); 3009 /* 3010 * We must restart the list traversal after every fini call 3011 * because a dlclose() call from the fini function or from 3012 * another thread might have modified the reference counts. 3013 */ 3014 break; 3015 } 3016 } while (elm != NULL); 3017 errmsg_restore(saved_msg); 3018 } 3019 3020 /* 3021 * Call the initialization functions for each of the objects in 3022 * "list". All of the objects are expected to have non-NULL init 3023 * functions. 3024 */ 3025 static void 3026 objlist_call_init(Objlist *list, RtldLockState *lockstate) 3027 { 3028 Objlist_Entry *elm; 3029 Obj_Entry *obj; 3030 struct dlerror_save *saved_msg; 3031 Elf_Addr *init_addr; 3032 void (*reg)(void (*)(void)); 3033 int index; 3034 3035 /* 3036 * Clean init_scanned flag so that objects can be rechecked and 3037 * possibly initialized earlier if any of vectors called below 3038 * cause the change by using dlopen. 3039 */ 3040 TAILQ_FOREACH(obj, &obj_list, next) { 3041 if (obj->marker) 3042 continue; 3043 obj->init_scanned = false; 3044 } 3045 3046 /* 3047 * Preserve the current error message since an init function might 3048 * call into the dynamic linker and overwrite it. 3049 */ 3050 saved_msg = errmsg_save(); 3051 STAILQ_FOREACH(elm, list, link) { 3052 if (elm->obj->init_done) /* Initialized early. */ 3053 continue; 3054 /* 3055 * Race: other thread might try to use this object before current 3056 * one completes the initialization. Not much can be done here 3057 * without better locking. 3058 */ 3059 elm->obj->init_done = true; 3060 hold_object(elm->obj); 3061 reg = NULL; 3062 if (elm->obj == obj_main && obj_main->crt_no_init) { 3063 reg = (void (*)(void (*)(void)))get_program_var_addr( 3064 "__libc_atexit", lockstate); 3065 } 3066 lock_release(rtld_bind_lock, lockstate); 3067 if (reg != NULL) { 3068 reg(rtld_exit); 3069 rtld_exit_ptr = rtld_nop_exit; 3070 } 3071 3072 /* 3073 * It is legal to have both DT_INIT and DT_INIT_ARRAY defined. 3074 * When this happens, DT_INIT is processed first. 3075 */ 3076 if (elm->obj->init != (Elf_Addr)NULL) { 3077 dbg("calling init function for %s at %p", elm->obj->path, 3078 (void *)elm->obj->init); 3079 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, (void *)elm->obj->init, 3080 0, 0, elm->obj->path); 3081 call_init_pointer(elm->obj, elm->obj->init); 3082 } 3083 init_addr = (Elf_Addr *)elm->obj->init_array; 3084 if (init_addr != NULL) { 3085 for (index = 0; index < elm->obj->init_array_num; index++) { 3086 if (init_addr[index] != 0 && init_addr[index] != 1) { 3087 dbg("calling init function for %s at %p", elm->obj->path, 3088 (void *)init_addr[index]); 3089 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, 3090 (void *)init_addr[index], 0, 0, elm->obj->path); 3091 call_init_pointer(elm->obj, init_addr[index]); 3092 } 3093 } 3094 } 3095 wlock_acquire(rtld_bind_lock, lockstate); 3096 unhold_object(elm->obj); 3097 } 3098 errmsg_restore(saved_msg); 3099 } 3100 3101 static void 3102 objlist_clear(Objlist *list) 3103 { 3104 Objlist_Entry *elm; 3105 3106 while (!STAILQ_EMPTY(list)) { 3107 elm = STAILQ_FIRST(list); 3108 STAILQ_REMOVE_HEAD(list, link); 3109 free(elm); 3110 } 3111 } 3112 3113 static Objlist_Entry * 3114 objlist_find(Objlist *list, const Obj_Entry *obj) 3115 { 3116 Objlist_Entry *elm; 3117 3118 STAILQ_FOREACH(elm, list, link) 3119 if (elm->obj == obj) 3120 return elm; 3121 return (NULL); 3122 } 3123 3124 static void 3125 objlist_init(Objlist *list) 3126 { 3127 STAILQ_INIT(list); 3128 } 3129 3130 static void 3131 objlist_push_head(Objlist *list, Obj_Entry *obj) 3132 { 3133 Objlist_Entry *elm; 3134 3135 elm = NEW(Objlist_Entry); 3136 elm->obj = obj; 3137 STAILQ_INSERT_HEAD(list, elm, link); 3138 } 3139 3140 static void 3141 objlist_push_tail(Objlist *list, Obj_Entry *obj) 3142 { 3143 Objlist_Entry *elm; 3144 3145 elm = NEW(Objlist_Entry); 3146 elm->obj = obj; 3147 STAILQ_INSERT_TAIL(list, elm, link); 3148 } 3149 3150 static void 3151 objlist_put_after(Objlist *list, Obj_Entry *listobj, Obj_Entry *obj) 3152 { 3153 Objlist_Entry *elm, *listelm; 3154 3155 STAILQ_FOREACH(listelm, list, link) { 3156 if (listelm->obj == listobj) 3157 break; 3158 } 3159 elm = NEW(Objlist_Entry); 3160 elm->obj = obj; 3161 if (listelm != NULL) 3162 STAILQ_INSERT_AFTER(list, listelm, elm, link); 3163 else 3164 STAILQ_INSERT_TAIL(list, elm, link); 3165 } 3166 3167 static void 3168 objlist_remove(Objlist *list, Obj_Entry *obj) 3169 { 3170 Objlist_Entry *elm; 3171 3172 if ((elm = objlist_find(list, obj)) != NULL) { 3173 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 3174 free(elm); 3175 } 3176 } 3177 3178 /* 3179 * Relocate dag rooted in the specified object. 3180 * Returns 0 on success, or -1 on failure. 3181 */ 3182 3183 static int 3184 relocate_object_dag(Obj_Entry *root, bool bind_now, Obj_Entry *rtldobj, 3185 int flags, RtldLockState *lockstate) 3186 { 3187 Objlist_Entry *elm; 3188 int error; 3189 3190 error = 0; 3191 STAILQ_FOREACH(elm, &root->dagmembers, link) { 3192 error = relocate_object(elm->obj, bind_now, rtldobj, flags, 3193 lockstate); 3194 if (error == -1) 3195 break; 3196 } 3197 return (error); 3198 } 3199 3200 /* 3201 * Prepare for, or clean after, relocating an object marked with 3202 * DT_TEXTREL or DF_TEXTREL. Before relocating, all read-only 3203 * segments are remapped read-write. After relocations are done, the 3204 * segment's permissions are returned back to the modes specified in 3205 * the phdrs. If any relocation happened, or always for wired 3206 * program, COW is triggered. 3207 */ 3208 static int 3209 reloc_textrel_prot(Obj_Entry *obj, bool before) 3210 { 3211 const Elf_Phdr *ph; 3212 void *base; 3213 size_t l, sz; 3214 int prot; 3215 3216 for (l = obj->phsize / sizeof(*ph), ph = obj->phdr; l > 0; 3217 l--, ph++) { 3218 if (ph->p_type != PT_LOAD || (ph->p_flags & PF_W) != 0) 3219 continue; 3220 base = obj->relocbase + rtld_trunc_page(ph->p_vaddr); 3221 sz = rtld_round_page(ph->p_vaddr + ph->p_filesz) - 3222 rtld_trunc_page(ph->p_vaddr); 3223 prot = before ? (PROT_READ | PROT_WRITE) : 3224 convert_prot(ph->p_flags); 3225 if (mprotect(base, sz, prot) == -1) { 3226 _rtld_error("%s: Cannot write-%sable text segment: %s", 3227 obj->path, before ? "en" : "dis", 3228 rtld_strerror(errno)); 3229 return (-1); 3230 } 3231 } 3232 return (0); 3233 } 3234 3235 /* Process RELR relative relocations. */ 3236 static void 3237 reloc_relr(Obj_Entry *obj) 3238 { 3239 const Elf_Relr *relr, *relrlim; 3240 Elf_Addr *where; 3241 3242 relrlim = (const Elf_Relr *)((const char *)obj->relr + obj->relrsize); 3243 for (relr = obj->relr; relr < relrlim; relr++) { 3244 Elf_Relr entry = *relr; 3245 3246 if ((entry & 1) == 0) { 3247 where = (Elf_Addr *)(obj->relocbase + entry); 3248 *where++ += (Elf_Addr)obj->relocbase; 3249 } else { 3250 for (long i = 0; (entry >>= 1) != 0; i++) 3251 if ((entry & 1) != 0) 3252 where[i] += (Elf_Addr)obj->relocbase; 3253 where += CHAR_BIT * sizeof(Elf_Relr) - 1; 3254 } 3255 } 3256 } 3257 3258 /* 3259 * Relocate single object. 3260 * Returns 0 on success, or -1 on failure. 3261 */ 3262 static int 3263 relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, 3264 int flags, RtldLockState *lockstate) 3265 { 3266 3267 if (obj->relocated) 3268 return (0); 3269 obj->relocated = true; 3270 if (obj != rtldobj) 3271 dbg("relocating \"%s\"", obj->path); 3272 3273 if (obj->symtab == NULL || obj->strtab == NULL || 3274 !(obj->valid_hash_sysv || obj->valid_hash_gnu)) 3275 dbg("object %s has no run-time symbol table", obj->path); 3276 3277 /* There are relocations to the write-protected text segment. */ 3278 if (obj->textrel && reloc_textrel_prot(obj, true) != 0) 3279 return (-1); 3280 3281 /* Process the non-PLT non-IFUNC relocations. */ 3282 if (reloc_non_plt(obj, rtldobj, flags, lockstate)) 3283 return (-1); 3284 reloc_relr(obj); 3285 3286 /* Re-protected the text segment. */ 3287 if (obj->textrel && reloc_textrel_prot(obj, false) != 0) 3288 return (-1); 3289 3290 /* Set the special PLT or GOT entries. */ 3291 init_pltgot(obj); 3292 3293 /* Process the PLT relocations. */ 3294 if (reloc_plt(obj, flags, lockstate) == -1) 3295 return (-1); 3296 /* Relocate the jump slots if we are doing immediate binding. */ 3297 if ((obj->bind_now || bind_now) && reloc_jmpslots(obj, flags, 3298 lockstate) == -1) 3299 return (-1); 3300 3301 if (!obj->mainprog && obj_enforce_relro(obj) == -1) 3302 return (-1); 3303 3304 /* 3305 * Set up the magic number and version in the Obj_Entry. These 3306 * were checked in the crt1.o from the original ElfKit, so we 3307 * set them for backward compatibility. 3308 */ 3309 obj->magic = RTLD_MAGIC; 3310 obj->version = RTLD_VERSION; 3311 3312 return (0); 3313 } 3314 3315 /* 3316 * Relocate newly-loaded shared objects. The argument is a pointer to 3317 * the Obj_Entry for the first such object. All objects from the first 3318 * to the end of the list of objects are relocated. Returns 0 on success, 3319 * or -1 on failure. 3320 */ 3321 static int 3322 relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj, 3323 int flags, RtldLockState *lockstate) 3324 { 3325 Obj_Entry *obj; 3326 int error; 3327 3328 for (error = 0, obj = first; obj != NULL; 3329 obj = TAILQ_NEXT(obj, next)) { 3330 if (obj->marker) 3331 continue; 3332 error = relocate_object(obj, bind_now, rtldobj, flags, 3333 lockstate); 3334 if (error == -1) 3335 break; 3336 } 3337 return (error); 3338 } 3339 3340 /* 3341 * The handling of R_MACHINE_IRELATIVE relocations and jumpslots 3342 * referencing STT_GNU_IFUNC symbols is postponed till the other 3343 * relocations are done. The indirect functions specified as 3344 * ifunc are allowed to call other symbols, so we need to have 3345 * objects relocated before asking for resolution from indirects. 3346 * 3347 * The R_MACHINE_IRELATIVE slots are resolved in greedy fashion, 3348 * instead of the usual lazy handling of PLT slots. It is 3349 * consistent with how GNU does it. 3350 */ 3351 static int 3352 resolve_object_ifunc(Obj_Entry *obj, bool bind_now, int flags, 3353 RtldLockState *lockstate) 3354 { 3355 3356 if (obj->ifuncs_resolved) 3357 return (0); 3358 obj->ifuncs_resolved = true; 3359 if (!obj->irelative && !obj->irelative_nonplt && 3360 !((obj->bind_now || bind_now) && obj->gnu_ifunc) && 3361 !obj->non_plt_gnu_ifunc) 3362 return (0); 3363 if (obj_disable_relro(obj) == -1 || 3364 (obj->irelative && reloc_iresolve(obj, lockstate) == -1) || 3365 (obj->irelative_nonplt && reloc_iresolve_nonplt(obj, 3366 lockstate) == -1) || 3367 ((obj->bind_now || bind_now) && obj->gnu_ifunc && 3368 reloc_gnu_ifunc(obj, flags, lockstate) == -1) || 3369 (obj->non_plt_gnu_ifunc && reloc_non_plt(obj, &obj_rtld, 3370 flags | SYMLOOK_IFUNC, lockstate) == -1) || 3371 obj_enforce_relro(obj) == -1) 3372 return (-1); 3373 return (0); 3374 } 3375 3376 static int 3377 initlist_objects_ifunc(Objlist *list, bool bind_now, int flags, 3378 RtldLockState *lockstate) 3379 { 3380 Objlist_Entry *elm; 3381 Obj_Entry *obj; 3382 3383 STAILQ_FOREACH(elm, list, link) { 3384 obj = elm->obj; 3385 if (obj->marker) 3386 continue; 3387 if (resolve_object_ifunc(obj, bind_now, flags, 3388 lockstate) == -1) 3389 return (-1); 3390 } 3391 return (0); 3392 } 3393 3394 /* 3395 * Cleanup procedure. It will be called (by the atexit mechanism) just 3396 * before the process exits. 3397 */ 3398 static void 3399 rtld_exit(void) 3400 { 3401 RtldLockState lockstate; 3402 3403 wlock_acquire(rtld_bind_lock, &lockstate); 3404 dbg("rtld_exit()"); 3405 objlist_call_fini(&list_fini, NULL, &lockstate); 3406 /* No need to remove the items from the list, since we are exiting. */ 3407 if (!libmap_disable) 3408 lm_fini(); 3409 lock_release(rtld_bind_lock, &lockstate); 3410 } 3411 3412 static void 3413 rtld_nop_exit(void) 3414 { 3415 } 3416 3417 /* 3418 * Iterate over a search path, translate each element, and invoke the 3419 * callback on the result. 3420 */ 3421 static void * 3422 path_enumerate(const char *path, path_enum_proc callback, 3423 const char *refobj_path, void *arg) 3424 { 3425 const char *trans; 3426 if (path == NULL) 3427 return (NULL); 3428 3429 path += strspn(path, ":;"); 3430 while (*path != '\0') { 3431 size_t len; 3432 char *res; 3433 3434 len = strcspn(path, ":;"); 3435 trans = lm_findn(refobj_path, path, len); 3436 if (trans) 3437 res = callback(trans, strlen(trans), arg); 3438 else 3439 res = callback(path, len, arg); 3440 3441 if (res != NULL) 3442 return (res); 3443 3444 path += len; 3445 path += strspn(path, ":;"); 3446 } 3447 3448 return (NULL); 3449 } 3450 3451 struct try_library_args { 3452 const char *name; 3453 size_t namelen; 3454 char *buffer; 3455 size_t buflen; 3456 int fd; 3457 }; 3458 3459 static void * 3460 try_library_path(const char *dir, size_t dirlen, void *param) 3461 { 3462 struct try_library_args *arg; 3463 int fd; 3464 3465 arg = param; 3466 if (*dir == '/' || trust) { 3467 char *pathname; 3468 3469 if (dirlen + 1 + arg->namelen + 1 > arg->buflen) 3470 return (NULL); 3471 3472 pathname = arg->buffer; 3473 strncpy(pathname, dir, dirlen); 3474 pathname[dirlen] = '/'; 3475 strcpy(pathname + dirlen + 1, arg->name); 3476 3477 dbg(" Trying \"%s\"", pathname); 3478 fd = open(pathname, O_RDONLY | O_CLOEXEC | O_VERIFY); 3479 if (fd >= 0) { 3480 dbg(" Opened \"%s\", fd %d", pathname, fd); 3481 pathname = xmalloc(dirlen + 1 + arg->namelen + 1); 3482 strcpy(pathname, arg->buffer); 3483 arg->fd = fd; 3484 return (pathname); 3485 } else { 3486 dbg(" Failed to open \"%s\": %s", 3487 pathname, rtld_strerror(errno)); 3488 } 3489 } 3490 return (NULL); 3491 } 3492 3493 static char * 3494 search_library_path(const char *name, const char *path, 3495 const char *refobj_path, int *fdp) 3496 { 3497 char *p; 3498 struct try_library_args arg; 3499 3500 if (path == NULL) 3501 return (NULL); 3502 3503 arg.name = name; 3504 arg.namelen = strlen(name); 3505 arg.buffer = xmalloc(PATH_MAX); 3506 arg.buflen = PATH_MAX; 3507 arg.fd = -1; 3508 3509 p = path_enumerate(path, try_library_path, refobj_path, &arg); 3510 *fdp = arg.fd; 3511 3512 free(arg.buffer); 3513 3514 return (p); 3515 } 3516 3517 3518 /* 3519 * Finds the library with the given name using the directory descriptors 3520 * listed in the LD_LIBRARY_PATH_FDS environment variable. 3521 * 3522 * Returns a freshly-opened close-on-exec file descriptor for the library, 3523 * or -1 if the library cannot be found. 3524 */ 3525 static char * 3526 search_library_pathfds(const char *name, const char *path, int *fdp) 3527 { 3528 char *envcopy, *fdstr, *found, *last_token; 3529 size_t len; 3530 int dirfd, fd; 3531 3532 dbg("%s('%s', '%s', fdp)", __func__, name, path); 3533 3534 /* Don't load from user-specified libdirs into setuid binaries. */ 3535 if (!trust) 3536 return (NULL); 3537 3538 /* We can't do anything if LD_LIBRARY_PATH_FDS isn't set. */ 3539 if (path == NULL) 3540 return (NULL); 3541 3542 /* LD_LIBRARY_PATH_FDS only works with relative paths. */ 3543 if (name[0] == '/') { 3544 dbg("Absolute path (%s) passed to %s", name, __func__); 3545 return (NULL); 3546 } 3547 3548 /* 3549 * Use strtok_r() to walk the FD:FD:FD list. This requires a local 3550 * copy of the path, as strtok_r rewrites separator tokens 3551 * with '\0'. 3552 */ 3553 found = NULL; 3554 envcopy = xstrdup(path); 3555 for (fdstr = strtok_r(envcopy, ":", &last_token); fdstr != NULL; 3556 fdstr = strtok_r(NULL, ":", &last_token)) { 3557 dirfd = parse_integer(fdstr); 3558 if (dirfd < 0) { 3559 _rtld_error("failed to parse directory FD: '%s'", 3560 fdstr); 3561 break; 3562 } 3563 fd = __sys_openat(dirfd, name, O_RDONLY | O_CLOEXEC | O_VERIFY); 3564 if (fd >= 0) { 3565 *fdp = fd; 3566 len = strlen(fdstr) + strlen(name) + 3; 3567 found = xmalloc(len); 3568 if (rtld_snprintf(found, len, "#%d/%s", dirfd, name) < 0) { 3569 _rtld_error("error generating '%d/%s'", 3570 dirfd, name); 3571 rtld_die(); 3572 } 3573 dbg("open('%s') => %d", found, fd); 3574 break; 3575 } 3576 } 3577 free(envcopy); 3578 3579 return (found); 3580 } 3581 3582 3583 int 3584 dlclose(void *handle) 3585 { 3586 RtldLockState lockstate; 3587 int error; 3588 3589 wlock_acquire(rtld_bind_lock, &lockstate); 3590 error = dlclose_locked(handle, &lockstate); 3591 lock_release(rtld_bind_lock, &lockstate); 3592 return (error); 3593 } 3594 3595 static int 3596 dlclose_locked(void *handle, RtldLockState *lockstate) 3597 { 3598 Obj_Entry *root; 3599 3600 root = dlcheck(handle); 3601 if (root == NULL) 3602 return (-1); 3603 LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount, 3604 root->path); 3605 3606 /* Unreference the object and its dependencies. */ 3607 root->dl_refcount--; 3608 3609 if (root->refcount == 1) { 3610 /* 3611 * The object will be no longer referenced, so we must unload it. 3612 * First, call the fini functions. 3613 */ 3614 objlist_call_fini(&list_fini, root, lockstate); 3615 3616 unref_dag(root); 3617 3618 /* Finish cleaning up the newly-unreferenced objects. */ 3619 GDB_STATE(RT_DELETE,&root->linkmap); 3620 unload_object(root, lockstate); 3621 GDB_STATE(RT_CONSISTENT,NULL); 3622 } else 3623 unref_dag(root); 3624 3625 LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL); 3626 return (0); 3627 } 3628 3629 char * 3630 dlerror(void) 3631 { 3632 if (*(lockinfo.dlerror_seen()) != 0) 3633 return (NULL); 3634 *lockinfo.dlerror_seen() = 1; 3635 return (lockinfo.dlerror_loc()); 3636 } 3637 3638 /* 3639 * This function is deprecated and has no effect. 3640 */ 3641 void 3642 dllockinit(void *context, 3643 void *(*_lock_create)(void *context) __unused, 3644 void (*_rlock_acquire)(void *lock) __unused, 3645 void (*_wlock_acquire)(void *lock) __unused, 3646 void (*_lock_release)(void *lock) __unused, 3647 void (*_lock_destroy)(void *lock) __unused, 3648 void (*context_destroy)(void *context)) 3649 { 3650 static void *cur_context; 3651 static void (*cur_context_destroy)(void *); 3652 3653 /* Just destroy the context from the previous call, if necessary. */ 3654 if (cur_context_destroy != NULL) 3655 cur_context_destroy(cur_context); 3656 cur_context = context; 3657 cur_context_destroy = context_destroy; 3658 } 3659 3660 void * 3661 dlopen(const char *name, int mode) 3662 { 3663 3664 return (rtld_dlopen(name, -1, mode)); 3665 } 3666 3667 void * 3668 fdlopen(int fd, int mode) 3669 { 3670 3671 return (rtld_dlopen(NULL, fd, mode)); 3672 } 3673 3674 static void * 3675 rtld_dlopen(const char *name, int fd, int mode) 3676 { 3677 RtldLockState lockstate; 3678 int lo_flags; 3679 3680 LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name); 3681 ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1"; 3682 if (ld_tracing != NULL) { 3683 rlock_acquire(rtld_bind_lock, &lockstate); 3684 if (sigsetjmp(lockstate.env, 0) != 0) 3685 lock_upgrade(rtld_bind_lock, &lockstate); 3686 environ = __DECONST(char **, *get_program_var_addr("environ", &lockstate)); 3687 lock_release(rtld_bind_lock, &lockstate); 3688 } 3689 lo_flags = RTLD_LO_DLOPEN; 3690 if (mode & RTLD_NODELETE) 3691 lo_flags |= RTLD_LO_NODELETE; 3692 if (mode & RTLD_NOLOAD) 3693 lo_flags |= RTLD_LO_NOLOAD; 3694 if (mode & RTLD_DEEPBIND) 3695 lo_flags |= RTLD_LO_DEEPBIND; 3696 if (ld_tracing != NULL) 3697 lo_flags |= RTLD_LO_TRACE | RTLD_LO_IGNSTLS; 3698 3699 return (dlopen_object(name, fd, obj_main, lo_flags, 3700 mode & (RTLD_MODEMASK | RTLD_GLOBAL), NULL)); 3701 } 3702 3703 static void 3704 dlopen_cleanup(Obj_Entry *obj, RtldLockState *lockstate) 3705 { 3706 3707 obj->dl_refcount--; 3708 unref_dag(obj); 3709 if (obj->refcount == 0) 3710 unload_object(obj, lockstate); 3711 } 3712 3713 static Obj_Entry * 3714 dlopen_object(const char *name, int fd, Obj_Entry *refobj, int lo_flags, 3715 int mode, RtldLockState *lockstate) 3716 { 3717 Obj_Entry *obj; 3718 Objlist initlist; 3719 RtldLockState mlockstate; 3720 int result; 3721 3722 dbg("dlopen_object name \"%s\" fd %d refobj \"%s\" lo_flags %#x mode %#x", 3723 name != NULL ? name : "<null>", fd, refobj == NULL ? "<null>" : 3724 refobj->path, lo_flags, mode); 3725 objlist_init(&initlist); 3726 3727 if (lockstate == NULL && !(lo_flags & RTLD_LO_EARLY)) { 3728 wlock_acquire(rtld_bind_lock, &mlockstate); 3729 lockstate = &mlockstate; 3730 } 3731 GDB_STATE(RT_ADD,NULL); 3732 3733 obj = NULL; 3734 if (name == NULL && fd == -1) { 3735 obj = obj_main; 3736 obj->refcount++; 3737 } else { 3738 obj = load_object(name, fd, refobj, lo_flags); 3739 } 3740 3741 if (obj) { 3742 obj->dl_refcount++; 3743 if (mode & RTLD_GLOBAL && objlist_find(&list_global, obj) == NULL) 3744 objlist_push_tail(&list_global, obj); 3745 3746 if (!obj->init_done) { 3747 /* We loaded something new and have to init something. */ 3748 if ((lo_flags & RTLD_LO_DEEPBIND) != 0) 3749 obj->symbolic = true; 3750 result = 0; 3751 if ((lo_flags & (RTLD_LO_EARLY | RTLD_LO_IGNSTLS)) == 0 && 3752 obj->static_tls && !allocate_tls_offset(obj)) { 3753 _rtld_error("%s: No space available " 3754 "for static Thread Local Storage", obj->path); 3755 result = -1; 3756 } 3757 if (result != -1) 3758 result = load_needed_objects(obj, lo_flags & (RTLD_LO_DLOPEN | 3759 RTLD_LO_EARLY | RTLD_LO_IGNSTLS | RTLD_LO_TRACE)); 3760 init_dag(obj); 3761 ref_dag(obj); 3762 if (result != -1) 3763 result = rtld_verify_versions(&obj->dagmembers); 3764 if (result != -1 && ld_tracing) 3765 goto trace; 3766 if (result == -1 || relocate_object_dag(obj, 3767 (mode & RTLD_MODEMASK) == RTLD_NOW, &obj_rtld, 3768 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 3769 lockstate) == -1) { 3770 dlopen_cleanup(obj, lockstate); 3771 obj = NULL; 3772 } else if (lo_flags & RTLD_LO_EARLY) { 3773 /* 3774 * Do not call the init functions for early loaded 3775 * filtees. The image is still not initialized enough 3776 * for them to work. 3777 * 3778 * Our object is found by the global object list and 3779 * will be ordered among all init calls done right 3780 * before transferring control to main. 3781 */ 3782 } else { 3783 /* Make list of init functions to call. */ 3784 initlist_add_objects(obj, obj, &initlist); 3785 } 3786 /* 3787 * Process all no_delete or global objects here, given 3788 * them own DAGs to prevent their dependencies from being 3789 * unloaded. This has to be done after we have loaded all 3790 * of the dependencies, so that we do not miss any. 3791 */ 3792 if (obj != NULL) 3793 process_z(obj); 3794 } else { 3795 /* 3796 * Bump the reference counts for objects on this DAG. If 3797 * this is the first dlopen() call for the object that was 3798 * already loaded as a dependency, initialize the dag 3799 * starting at it. 3800 */ 3801 init_dag(obj); 3802 ref_dag(obj); 3803 3804 if ((lo_flags & RTLD_LO_TRACE) != 0) 3805 goto trace; 3806 } 3807 if (obj != NULL && ((lo_flags & RTLD_LO_NODELETE) != 0 || 3808 obj->z_nodelete) && !obj->ref_nodel) { 3809 dbg("obj %s nodelete", obj->path); 3810 ref_dag(obj); 3811 obj->z_nodelete = obj->ref_nodel = true; 3812 } 3813 } 3814 3815 LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0, 3816 name); 3817 GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL); 3818 3819 if ((lo_flags & RTLD_LO_EARLY) == 0) { 3820 map_stacks_exec(lockstate); 3821 if (obj != NULL) 3822 distribute_static_tls(&initlist, lockstate); 3823 } 3824 3825 if (initlist_objects_ifunc(&initlist, (mode & RTLD_MODEMASK) == RTLD_NOW, 3826 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 3827 lockstate) == -1) { 3828 objlist_clear(&initlist); 3829 dlopen_cleanup(obj, lockstate); 3830 if (lockstate == &mlockstate) 3831 lock_release(rtld_bind_lock, lockstate); 3832 return (NULL); 3833 } 3834 3835 if (!(lo_flags & RTLD_LO_EARLY)) { 3836 /* Call the init functions. */ 3837 objlist_call_init(&initlist, lockstate); 3838 } 3839 objlist_clear(&initlist); 3840 if (lockstate == &mlockstate) 3841 lock_release(rtld_bind_lock, lockstate); 3842 return (obj); 3843 trace: 3844 trace_loaded_objects(obj, false); 3845 if (lockstate == &mlockstate) 3846 lock_release(rtld_bind_lock, lockstate); 3847 exit(0); 3848 } 3849 3850 static void * 3851 do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve, 3852 int flags) 3853 { 3854 DoneList donelist; 3855 const Obj_Entry *obj, *defobj; 3856 const Elf_Sym *def; 3857 SymLook req; 3858 RtldLockState lockstate; 3859 tls_index ti; 3860 void *sym; 3861 int res; 3862 3863 def = NULL; 3864 defobj = NULL; 3865 symlook_init(&req, name); 3866 req.ventry = ve; 3867 req.flags = flags | SYMLOOK_IN_PLT; 3868 req.lockstate = &lockstate; 3869 3870 LD_UTRACE(UTRACE_DLSYM_START, handle, NULL, 0, 0, name); 3871 rlock_acquire(rtld_bind_lock, &lockstate); 3872 if (sigsetjmp(lockstate.env, 0) != 0) 3873 lock_upgrade(rtld_bind_lock, &lockstate); 3874 if (handle == NULL || handle == RTLD_NEXT || 3875 handle == RTLD_DEFAULT || handle == RTLD_SELF) { 3876 3877 if ((obj = obj_from_addr(retaddr)) == NULL) { 3878 _rtld_error("Cannot determine caller's shared object"); 3879 lock_release(rtld_bind_lock, &lockstate); 3880 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 3881 return (NULL); 3882 } 3883 if (handle == NULL) { /* Just the caller's shared object. */ 3884 res = symlook_obj(&req, obj); 3885 if (res == 0) { 3886 def = req.sym_out; 3887 defobj = req.defobj_out; 3888 } 3889 } else if (handle == RTLD_NEXT || /* Objects after caller's */ 3890 handle == RTLD_SELF) { /* ... caller included */ 3891 if (handle == RTLD_NEXT) 3892 obj = globallist_next(obj); 3893 for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 3894 if (obj->marker) 3895 continue; 3896 res = symlook_obj(&req, obj); 3897 if (res == 0) { 3898 if (def == NULL || (ld_dynamic_weak && 3899 ELF_ST_BIND(req.sym_out->st_info) != STB_WEAK)) { 3900 def = req.sym_out; 3901 defobj = req.defobj_out; 3902 if (!ld_dynamic_weak || 3903 ELF_ST_BIND(def->st_info) != STB_WEAK) 3904 break; 3905 } 3906 } 3907 } 3908 /* 3909 * Search the dynamic linker itself, and possibly resolve the 3910 * symbol from there. This is how the application links to 3911 * dynamic linker services such as dlopen. 3912 * Note that we ignore ld_dynamic_weak == false case, 3913 * always overriding weak symbols by rtld definitions. 3914 */ 3915 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 3916 res = symlook_obj(&req, &obj_rtld); 3917 if (res == 0) { 3918 def = req.sym_out; 3919 defobj = req.defobj_out; 3920 } 3921 } 3922 } else { 3923 assert(handle == RTLD_DEFAULT); 3924 res = symlook_default(&req, obj); 3925 if (res == 0) { 3926 defobj = req.defobj_out; 3927 def = req.sym_out; 3928 } 3929 } 3930 } else { 3931 if ((obj = dlcheck(handle)) == NULL) { 3932 lock_release(rtld_bind_lock, &lockstate); 3933 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 3934 return (NULL); 3935 } 3936 3937 donelist_init(&donelist); 3938 if (obj->mainprog) { 3939 /* Handle obtained by dlopen(NULL, ...) implies global scope. */ 3940 res = symlook_global(&req, &donelist); 3941 if (res == 0) { 3942 def = req.sym_out; 3943 defobj = req.defobj_out; 3944 } 3945 /* 3946 * Search the dynamic linker itself, and possibly resolve the 3947 * symbol from there. This is how the application links to 3948 * dynamic linker services such as dlopen. 3949 */ 3950 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 3951 res = symlook_obj(&req, &obj_rtld); 3952 if (res == 0) { 3953 def = req.sym_out; 3954 defobj = req.defobj_out; 3955 } 3956 } 3957 } 3958 else { 3959 /* Search the whole DAG rooted at the given object. */ 3960 res = symlook_list(&req, &obj->dagmembers, &donelist); 3961 if (res == 0) { 3962 def = req.sym_out; 3963 defobj = req.defobj_out; 3964 } 3965 } 3966 } 3967 3968 if (def != NULL) { 3969 lock_release(rtld_bind_lock, &lockstate); 3970 3971 /* 3972 * The value required by the caller is derived from the value 3973 * of the symbol. this is simply the relocated value of the 3974 * symbol. 3975 */ 3976 if (ELF_ST_TYPE(def->st_info) == STT_FUNC) 3977 sym = make_function_pointer(def, defobj); 3978 else if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 3979 sym = rtld_resolve_ifunc(defobj, def); 3980 else if (ELF_ST_TYPE(def->st_info) == STT_TLS) { 3981 ti.ti_module = defobj->tlsindex; 3982 ti.ti_offset = def->st_value; 3983 sym = __tls_get_addr(&ti); 3984 } else 3985 sym = defobj->relocbase + def->st_value; 3986 LD_UTRACE(UTRACE_DLSYM_STOP, handle, sym, 0, 0, name); 3987 return (sym); 3988 } 3989 3990 _rtld_error("Undefined symbol \"%s%s%s\"", name, ve != NULL ? "@" : "", 3991 ve != NULL ? ve->name : ""); 3992 lock_release(rtld_bind_lock, &lockstate); 3993 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 3994 return (NULL); 3995 } 3996 3997 void * 3998 dlsym(void *handle, const char *name) 3999 { 4000 return (do_dlsym(handle, name, __builtin_return_address(0), NULL, 4001 SYMLOOK_DLSYM)); 4002 } 4003 4004 dlfunc_t 4005 dlfunc(void *handle, const char *name) 4006 { 4007 union { 4008 void *d; 4009 dlfunc_t f; 4010 } rv; 4011 4012 rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL, 4013 SYMLOOK_DLSYM); 4014 return (rv.f); 4015 } 4016 4017 void * 4018 dlvsym(void *handle, const char *name, const char *version) 4019 { 4020 Ver_Entry ventry; 4021 4022 ventry.name = version; 4023 ventry.file = NULL; 4024 ventry.hash = elf_hash(version); 4025 ventry.flags= 0; 4026 return (do_dlsym(handle, name, __builtin_return_address(0), &ventry, 4027 SYMLOOK_DLSYM)); 4028 } 4029 4030 int 4031 _rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info) 4032 { 4033 const Obj_Entry *obj; 4034 RtldLockState lockstate; 4035 4036 rlock_acquire(rtld_bind_lock, &lockstate); 4037 obj = obj_from_addr(addr); 4038 if (obj == NULL) { 4039 _rtld_error("No shared object contains address"); 4040 lock_release(rtld_bind_lock, &lockstate); 4041 return (0); 4042 } 4043 rtld_fill_dl_phdr_info(obj, phdr_info); 4044 lock_release(rtld_bind_lock, &lockstate); 4045 return (1); 4046 } 4047 4048 int 4049 dladdr(const void *addr, Dl_info *info) 4050 { 4051 const Obj_Entry *obj; 4052 const Elf_Sym *def; 4053 void *symbol_addr; 4054 unsigned long symoffset; 4055 RtldLockState lockstate; 4056 4057 rlock_acquire(rtld_bind_lock, &lockstate); 4058 obj = obj_from_addr(addr); 4059 if (obj == NULL) { 4060 _rtld_error("No shared object contains address"); 4061 lock_release(rtld_bind_lock, &lockstate); 4062 return (0); 4063 } 4064 info->dli_fname = obj->path; 4065 info->dli_fbase = obj->mapbase; 4066 info->dli_saddr = (void *)0; 4067 info->dli_sname = NULL; 4068 4069 /* 4070 * Walk the symbol list looking for the symbol whose address is 4071 * closest to the address sent in. 4072 */ 4073 for (symoffset = 0; symoffset < obj->dynsymcount; symoffset++) { 4074 def = obj->symtab + symoffset; 4075 4076 /* 4077 * For skip the symbol if st_shndx is either SHN_UNDEF or 4078 * SHN_COMMON. 4079 */ 4080 if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON) 4081 continue; 4082 4083 /* 4084 * If the symbol is greater than the specified address, or if it 4085 * is further away from addr than the current nearest symbol, 4086 * then reject it. 4087 */ 4088 symbol_addr = obj->relocbase + def->st_value; 4089 if (symbol_addr > addr || symbol_addr < info->dli_saddr) 4090 continue; 4091 4092 /* Update our idea of the nearest symbol. */ 4093 info->dli_sname = obj->strtab + def->st_name; 4094 info->dli_saddr = symbol_addr; 4095 4096 /* Exact match? */ 4097 if (info->dli_saddr == addr) 4098 break; 4099 } 4100 lock_release(rtld_bind_lock, &lockstate); 4101 return (1); 4102 } 4103 4104 int 4105 dlinfo(void *handle, int request, void *p) 4106 { 4107 const Obj_Entry *obj; 4108 RtldLockState lockstate; 4109 int error; 4110 4111 rlock_acquire(rtld_bind_lock, &lockstate); 4112 4113 if (handle == NULL || handle == RTLD_SELF) { 4114 void *retaddr; 4115 4116 retaddr = __builtin_return_address(0); /* __GNUC__ only */ 4117 if ((obj = obj_from_addr(retaddr)) == NULL) 4118 _rtld_error("Cannot determine caller's shared object"); 4119 } else 4120 obj = dlcheck(handle); 4121 4122 if (obj == NULL) { 4123 lock_release(rtld_bind_lock, &lockstate); 4124 return (-1); 4125 } 4126 4127 error = 0; 4128 switch (request) { 4129 case RTLD_DI_LINKMAP: 4130 *((struct link_map const **)p) = &obj->linkmap; 4131 break; 4132 case RTLD_DI_ORIGIN: 4133 error = rtld_dirname(obj->path, p); 4134 break; 4135 4136 case RTLD_DI_SERINFOSIZE: 4137 case RTLD_DI_SERINFO: 4138 error = do_search_info(obj, request, (struct dl_serinfo *)p); 4139 break; 4140 4141 default: 4142 _rtld_error("Invalid request %d passed to dlinfo()", request); 4143 error = -1; 4144 } 4145 4146 lock_release(rtld_bind_lock, &lockstate); 4147 4148 return (error); 4149 } 4150 4151 static void 4152 rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info) 4153 { 4154 uintptr_t **dtvp; 4155 4156 phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase; 4157 phdr_info->dlpi_name = obj->path; 4158 phdr_info->dlpi_phdr = obj->phdr; 4159 phdr_info->dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]); 4160 phdr_info->dlpi_tls_modid = obj->tlsindex; 4161 dtvp = &_tcb_get()->tcb_dtv; 4162 phdr_info->dlpi_tls_data = (char *)tls_get_addr_slow(dtvp, 4163 obj->tlsindex, 0, true) + TLS_DTV_OFFSET; 4164 phdr_info->dlpi_adds = obj_loads; 4165 phdr_info->dlpi_subs = obj_loads - obj_count; 4166 } 4167 4168 int 4169 dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param) 4170 { 4171 struct dl_phdr_info phdr_info; 4172 Obj_Entry *obj, marker; 4173 RtldLockState bind_lockstate, phdr_lockstate; 4174 int error; 4175 4176 init_marker(&marker); 4177 error = 0; 4178 4179 wlock_acquire(rtld_phdr_lock, &phdr_lockstate); 4180 wlock_acquire(rtld_bind_lock, &bind_lockstate); 4181 for (obj = globallist_curr(TAILQ_FIRST(&obj_list)); obj != NULL;) { 4182 TAILQ_INSERT_AFTER(&obj_list, obj, &marker, next); 4183 rtld_fill_dl_phdr_info(obj, &phdr_info); 4184 hold_object(obj); 4185 lock_release(rtld_bind_lock, &bind_lockstate); 4186 4187 error = callback(&phdr_info, sizeof phdr_info, param); 4188 4189 wlock_acquire(rtld_bind_lock, &bind_lockstate); 4190 unhold_object(obj); 4191 obj = globallist_next(&marker); 4192 TAILQ_REMOVE(&obj_list, &marker, next); 4193 if (error != 0) { 4194 lock_release(rtld_bind_lock, &bind_lockstate); 4195 lock_release(rtld_phdr_lock, &phdr_lockstate); 4196 return (error); 4197 } 4198 } 4199 4200 if (error == 0) { 4201 rtld_fill_dl_phdr_info(&obj_rtld, &phdr_info); 4202 lock_release(rtld_bind_lock, &bind_lockstate); 4203 error = callback(&phdr_info, sizeof(phdr_info), param); 4204 } 4205 lock_release(rtld_phdr_lock, &phdr_lockstate); 4206 return (error); 4207 } 4208 4209 static void * 4210 fill_search_info(const char *dir, size_t dirlen, void *param) 4211 { 4212 struct fill_search_info_args *arg; 4213 4214 arg = param; 4215 4216 if (arg->request == RTLD_DI_SERINFOSIZE) { 4217 arg->serinfo->dls_cnt ++; 4218 arg->serinfo->dls_size += sizeof(struct dl_serpath) + dirlen + 1; 4219 } else { 4220 struct dl_serpath *s_entry; 4221 4222 s_entry = arg->serpath; 4223 s_entry->dls_name = arg->strspace; 4224 s_entry->dls_flags = arg->flags; 4225 4226 strncpy(arg->strspace, dir, dirlen); 4227 arg->strspace[dirlen] = '\0'; 4228 4229 arg->strspace += dirlen + 1; 4230 arg->serpath++; 4231 } 4232 4233 return (NULL); 4234 } 4235 4236 static int 4237 do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info) 4238 { 4239 struct dl_serinfo _info; 4240 struct fill_search_info_args args; 4241 4242 args.request = RTLD_DI_SERINFOSIZE; 4243 args.serinfo = &_info; 4244 4245 _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 4246 _info.dls_cnt = 0; 4247 4248 path_enumerate(obj->rpath, fill_search_info, NULL, &args); 4249 path_enumerate(ld_library_path, fill_search_info, NULL, &args); 4250 path_enumerate(obj->runpath, fill_search_info, NULL, &args); 4251 path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, &args); 4252 if (!obj->z_nodeflib) 4253 path_enumerate(ld_standard_library_path, fill_search_info, NULL, &args); 4254 4255 4256 if (request == RTLD_DI_SERINFOSIZE) { 4257 info->dls_size = _info.dls_size; 4258 info->dls_cnt = _info.dls_cnt; 4259 return (0); 4260 } 4261 4262 if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) { 4263 _rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()"); 4264 return (-1); 4265 } 4266 4267 args.request = RTLD_DI_SERINFO; 4268 args.serinfo = info; 4269 args.serpath = &info->dls_serpath[0]; 4270 args.strspace = (char *)&info->dls_serpath[_info.dls_cnt]; 4271 4272 args.flags = LA_SER_RUNPATH; 4273 if (path_enumerate(obj->rpath, fill_search_info, NULL, &args) != NULL) 4274 return (-1); 4275 4276 args.flags = LA_SER_LIBPATH; 4277 if (path_enumerate(ld_library_path, fill_search_info, NULL, &args) != NULL) 4278 return (-1); 4279 4280 args.flags = LA_SER_RUNPATH; 4281 if (path_enumerate(obj->runpath, fill_search_info, NULL, &args) != NULL) 4282 return (-1); 4283 4284 args.flags = LA_SER_CONFIG; 4285 if (path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, &args) 4286 != NULL) 4287 return (-1); 4288 4289 args.flags = LA_SER_DEFAULT; 4290 if (!obj->z_nodeflib && path_enumerate(ld_standard_library_path, 4291 fill_search_info, NULL, &args) != NULL) 4292 return (-1); 4293 return (0); 4294 } 4295 4296 static int 4297 rtld_dirname(const char *path, char *bname) 4298 { 4299 const char *endp; 4300 4301 /* Empty or NULL string gets treated as "." */ 4302 if (path == NULL || *path == '\0') { 4303 bname[0] = '.'; 4304 bname[1] = '\0'; 4305 return (0); 4306 } 4307 4308 /* Strip trailing slashes */ 4309 endp = path + strlen(path) - 1; 4310 while (endp > path && *endp == '/') 4311 endp--; 4312 4313 /* Find the start of the dir */ 4314 while (endp > path && *endp != '/') 4315 endp--; 4316 4317 /* Either the dir is "/" or there are no slashes */ 4318 if (endp == path) { 4319 bname[0] = *endp == '/' ? '/' : '.'; 4320 bname[1] = '\0'; 4321 return (0); 4322 } else { 4323 do { 4324 endp--; 4325 } while (endp > path && *endp == '/'); 4326 } 4327 4328 if (endp - path + 2 > PATH_MAX) 4329 { 4330 _rtld_error("Filename is too long: %s", path); 4331 return(-1); 4332 } 4333 4334 strncpy(bname, path, endp - path + 1); 4335 bname[endp - path + 1] = '\0'; 4336 return (0); 4337 } 4338 4339 static int 4340 rtld_dirname_abs(const char *path, char *base) 4341 { 4342 char *last; 4343 4344 if (realpath(path, base) == NULL) { 4345 _rtld_error("realpath \"%s\" failed (%s)", path, 4346 rtld_strerror(errno)); 4347 return (-1); 4348 } 4349 dbg("%s -> %s", path, base); 4350 last = strrchr(base, '/'); 4351 if (last == NULL) { 4352 _rtld_error("non-abs result from realpath \"%s\"", path); 4353 return (-1); 4354 } 4355 if (last != base) 4356 *last = '\0'; 4357 return (0); 4358 } 4359 4360 static void 4361 linkmap_add(Obj_Entry *obj) 4362 { 4363 struct link_map *l, *prev; 4364 4365 l = &obj->linkmap; 4366 l->l_name = obj->path; 4367 l->l_base = obj->mapbase; 4368 l->l_ld = obj->dynamic; 4369 l->l_addr = obj->relocbase; 4370 4371 if (r_debug.r_map == NULL) { 4372 r_debug.r_map = l; 4373 return; 4374 } 4375 4376 /* 4377 * Scan to the end of the list, but not past the entry for the 4378 * dynamic linker, which we want to keep at the very end. 4379 */ 4380 for (prev = r_debug.r_map; 4381 prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap; 4382 prev = prev->l_next) 4383 ; 4384 4385 /* Link in the new entry. */ 4386 l->l_prev = prev; 4387 l->l_next = prev->l_next; 4388 if (l->l_next != NULL) 4389 l->l_next->l_prev = l; 4390 prev->l_next = l; 4391 } 4392 4393 static void 4394 linkmap_delete(Obj_Entry *obj) 4395 { 4396 struct link_map *l; 4397 4398 l = &obj->linkmap; 4399 if (l->l_prev == NULL) { 4400 if ((r_debug.r_map = l->l_next) != NULL) 4401 l->l_next->l_prev = NULL; 4402 return; 4403 } 4404 4405 if ((l->l_prev->l_next = l->l_next) != NULL) 4406 l->l_next->l_prev = l->l_prev; 4407 } 4408 4409 /* 4410 * Function for the debugger to set a breakpoint on to gain control. 4411 * 4412 * The two parameters allow the debugger to easily find and determine 4413 * what the runtime loader is doing and to whom it is doing it. 4414 * 4415 * When the loadhook trap is hit (r_debug_state, set at program 4416 * initialization), the arguments can be found on the stack: 4417 * 4418 * +8 struct link_map *m 4419 * +4 struct r_debug *rd 4420 * +0 RetAddr 4421 */ 4422 void 4423 r_debug_state(struct r_debug* rd __unused, struct link_map *m __unused) 4424 { 4425 /* 4426 * The following is a hack to force the compiler to emit calls to 4427 * this function, even when optimizing. If the function is empty, 4428 * the compiler is not obliged to emit any code for calls to it, 4429 * even when marked __noinline. However, gdb depends on those 4430 * calls being made. 4431 */ 4432 __compiler_membar(); 4433 } 4434 4435 /* 4436 * A function called after init routines have completed. This can be used to 4437 * break before a program's entry routine is called, and can be used when 4438 * main is not available in the symbol table. 4439 */ 4440 void 4441 _r_debug_postinit(struct link_map *m __unused) 4442 { 4443 4444 /* See r_debug_state(). */ 4445 __compiler_membar(); 4446 } 4447 4448 static void 4449 release_object(Obj_Entry *obj) 4450 { 4451 4452 if (obj->holdcount > 0) { 4453 obj->unholdfree = true; 4454 return; 4455 } 4456 munmap(obj->mapbase, obj->mapsize); 4457 linkmap_delete(obj); 4458 obj_free(obj); 4459 } 4460 4461 /* 4462 * Get address of the pointer variable in the main program. 4463 * Prefer non-weak symbol over the weak one. 4464 */ 4465 static const void ** 4466 get_program_var_addr(const char *name, RtldLockState *lockstate) 4467 { 4468 SymLook req; 4469 DoneList donelist; 4470 4471 symlook_init(&req, name); 4472 req.lockstate = lockstate; 4473 donelist_init(&donelist); 4474 if (symlook_global(&req, &donelist) != 0) 4475 return (NULL); 4476 if (ELF_ST_TYPE(req.sym_out->st_info) == STT_FUNC) 4477 return ((const void **)make_function_pointer(req.sym_out, 4478 req.defobj_out)); 4479 else if (ELF_ST_TYPE(req.sym_out->st_info) == STT_GNU_IFUNC) 4480 return ((const void **)rtld_resolve_ifunc(req.defobj_out, req.sym_out)); 4481 else 4482 return ((const void **)(req.defobj_out->relocbase + 4483 req.sym_out->st_value)); 4484 } 4485 4486 /* 4487 * Set a pointer variable in the main program to the given value. This 4488 * is used to set key variables such as "environ" before any of the 4489 * init functions are called. 4490 */ 4491 static void 4492 set_program_var(const char *name, const void *value) 4493 { 4494 const void **addr; 4495 4496 if ((addr = get_program_var_addr(name, NULL)) != NULL) { 4497 dbg("\"%s\": *%p <-- %p", name, addr, value); 4498 *addr = value; 4499 } 4500 } 4501 4502 /* 4503 * Search the global objects, including dependencies and main object, 4504 * for the given symbol. 4505 */ 4506 static int 4507 symlook_global(SymLook *req, DoneList *donelist) 4508 { 4509 SymLook req1; 4510 const Objlist_Entry *elm; 4511 int res; 4512 4513 symlook_init_from_req(&req1, req); 4514 4515 /* Search all objects loaded at program start up. */ 4516 if (req->defobj_out == NULL || (ld_dynamic_weak && 4517 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK)) { 4518 res = symlook_list(&req1, &list_main, donelist); 4519 if (res == 0 && (!ld_dynamic_weak || req->defobj_out == NULL || 4520 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4521 req->sym_out = req1.sym_out; 4522 req->defobj_out = req1.defobj_out; 4523 assert(req->defobj_out != NULL); 4524 } 4525 } 4526 4527 /* Search all DAGs whose roots are RTLD_GLOBAL objects. */ 4528 STAILQ_FOREACH(elm, &list_global, link) { 4529 if (req->defobj_out != NULL && (!ld_dynamic_weak || 4530 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK)) 4531 break; 4532 res = symlook_list(&req1, &elm->obj->dagmembers, donelist); 4533 if (res == 0 && (req->defobj_out == NULL || 4534 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4535 req->sym_out = req1.sym_out; 4536 req->defobj_out = req1.defobj_out; 4537 assert(req->defobj_out != NULL); 4538 } 4539 } 4540 4541 return (req->sym_out != NULL ? 0 : ESRCH); 4542 } 4543 4544 /* 4545 * Given a symbol name in a referencing object, find the corresponding 4546 * definition of the symbol. Returns a pointer to the symbol, or NULL if 4547 * no definition was found. Returns a pointer to the Obj_Entry of the 4548 * defining object via the reference parameter DEFOBJ_OUT. 4549 */ 4550 static int 4551 symlook_default(SymLook *req, const Obj_Entry *refobj) 4552 { 4553 DoneList donelist; 4554 const Objlist_Entry *elm; 4555 SymLook req1; 4556 int res; 4557 4558 donelist_init(&donelist); 4559 symlook_init_from_req(&req1, req); 4560 4561 /* 4562 * Look first in the referencing object if linked symbolically, 4563 * and similarly handle protected symbols. 4564 */ 4565 res = symlook_obj(&req1, refobj); 4566 if (res == 0 && (refobj->symbolic || 4567 ELF_ST_VISIBILITY(req1.sym_out->st_other) == STV_PROTECTED)) { 4568 req->sym_out = req1.sym_out; 4569 req->defobj_out = req1.defobj_out; 4570 assert(req->defobj_out != NULL); 4571 } 4572 if (refobj->symbolic || req->defobj_out != NULL) 4573 donelist_check(&donelist, refobj); 4574 4575 symlook_global(req, &donelist); 4576 4577 /* Search all dlopened DAGs containing the referencing object. */ 4578 STAILQ_FOREACH(elm, &refobj->dldags, link) { 4579 if (req->sym_out != NULL && (!ld_dynamic_weak || 4580 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK)) 4581 break; 4582 res = symlook_list(&req1, &elm->obj->dagmembers, &donelist); 4583 if (res == 0 && (req->sym_out == NULL || 4584 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4585 req->sym_out = req1.sym_out; 4586 req->defobj_out = req1.defobj_out; 4587 assert(req->defobj_out != NULL); 4588 } 4589 } 4590 4591 /* 4592 * Search the dynamic linker itself, and possibly resolve the 4593 * symbol from there. This is how the application links to 4594 * dynamic linker services such as dlopen. 4595 */ 4596 if (req->sym_out == NULL || 4597 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 4598 res = symlook_obj(&req1, &obj_rtld); 4599 if (res == 0) { 4600 req->sym_out = req1.sym_out; 4601 req->defobj_out = req1.defobj_out; 4602 assert(req->defobj_out != NULL); 4603 } 4604 } 4605 4606 return (req->sym_out != NULL ? 0 : ESRCH); 4607 } 4608 4609 static int 4610 symlook_list(SymLook *req, const Objlist *objlist, DoneList *dlp) 4611 { 4612 const Elf_Sym *def; 4613 const Obj_Entry *defobj; 4614 const Objlist_Entry *elm; 4615 SymLook req1; 4616 int res; 4617 4618 def = NULL; 4619 defobj = NULL; 4620 STAILQ_FOREACH(elm, objlist, link) { 4621 if (donelist_check(dlp, elm->obj)) 4622 continue; 4623 symlook_init_from_req(&req1, req); 4624 if ((res = symlook_obj(&req1, elm->obj)) == 0) { 4625 if (def == NULL || (ld_dynamic_weak && 4626 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4627 def = req1.sym_out; 4628 defobj = req1.defobj_out; 4629 if (!ld_dynamic_weak || ELF_ST_BIND(def->st_info) != STB_WEAK) 4630 break; 4631 } 4632 } 4633 } 4634 if (def != NULL) { 4635 req->sym_out = def; 4636 req->defobj_out = defobj; 4637 return (0); 4638 } 4639 return (ESRCH); 4640 } 4641 4642 /* 4643 * Search the chain of DAGS cointed to by the given Needed_Entry 4644 * for a symbol of the given name. Each DAG is scanned completely 4645 * before advancing to the next one. Returns a pointer to the symbol, 4646 * or NULL if no definition was found. 4647 */ 4648 static int 4649 symlook_needed(SymLook *req, const Needed_Entry *needed, DoneList *dlp) 4650 { 4651 const Elf_Sym *def; 4652 const Needed_Entry *n; 4653 const Obj_Entry *defobj; 4654 SymLook req1; 4655 int res; 4656 4657 def = NULL; 4658 defobj = NULL; 4659 symlook_init_from_req(&req1, req); 4660 for (n = needed; n != NULL; n = n->next) { 4661 if (n->obj == NULL || 4662 (res = symlook_list(&req1, &n->obj->dagmembers, dlp)) != 0) 4663 continue; 4664 if (def == NULL || (ld_dynamic_weak && 4665 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4666 def = req1.sym_out; 4667 defobj = req1.defobj_out; 4668 if (!ld_dynamic_weak || ELF_ST_BIND(def->st_info) != STB_WEAK) 4669 break; 4670 } 4671 } 4672 if (def != NULL) { 4673 req->sym_out = def; 4674 req->defobj_out = defobj; 4675 return (0); 4676 } 4677 return (ESRCH); 4678 } 4679 4680 /* 4681 * Search the symbol table of a single shared object for a symbol of 4682 * the given name and version, if requested. Returns a pointer to the 4683 * symbol, or NULL if no definition was found. If the object is 4684 * filter, return filtered symbol from filtee. 4685 * 4686 * The symbol's hash value is passed in for efficiency reasons; that 4687 * eliminates many recomputations of the hash value. 4688 */ 4689 int 4690 symlook_obj(SymLook *req, const Obj_Entry *obj) 4691 { 4692 DoneList donelist; 4693 SymLook req1; 4694 int flags, res, mres; 4695 4696 /* 4697 * If there is at least one valid hash at this point, we prefer to 4698 * use the faster GNU version if available. 4699 */ 4700 if (obj->valid_hash_gnu) 4701 mres = symlook_obj1_gnu(req, obj); 4702 else if (obj->valid_hash_sysv) 4703 mres = symlook_obj1_sysv(req, obj); 4704 else 4705 return (EINVAL); 4706 4707 if (mres == 0) { 4708 if (obj->needed_filtees != NULL) { 4709 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; 4710 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 4711 donelist_init(&donelist); 4712 symlook_init_from_req(&req1, req); 4713 res = symlook_needed(&req1, obj->needed_filtees, &donelist); 4714 if (res == 0) { 4715 req->sym_out = req1.sym_out; 4716 req->defobj_out = req1.defobj_out; 4717 } 4718 return (res); 4719 } 4720 if (obj->needed_aux_filtees != NULL) { 4721 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; 4722 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 4723 donelist_init(&donelist); 4724 symlook_init_from_req(&req1, req); 4725 res = symlook_needed(&req1, obj->needed_aux_filtees, &donelist); 4726 if (res == 0) { 4727 req->sym_out = req1.sym_out; 4728 req->defobj_out = req1.defobj_out; 4729 return (res); 4730 } 4731 } 4732 } 4733 return (mres); 4734 } 4735 4736 /* Symbol match routine common to both hash functions */ 4737 static bool 4738 matched_symbol(SymLook *req, const Obj_Entry *obj, Sym_Match_Result *result, 4739 const unsigned long symnum) 4740 { 4741 Elf_Versym verndx; 4742 const Elf_Sym *symp; 4743 const char *strp; 4744 4745 symp = obj->symtab + symnum; 4746 strp = obj->strtab + symp->st_name; 4747 4748 switch (ELF_ST_TYPE(symp->st_info)) { 4749 case STT_FUNC: 4750 case STT_NOTYPE: 4751 case STT_OBJECT: 4752 case STT_COMMON: 4753 case STT_GNU_IFUNC: 4754 if (symp->st_value == 0) 4755 return (false); 4756 /* fallthrough */ 4757 case STT_TLS: 4758 if (symp->st_shndx != SHN_UNDEF) 4759 break; 4760 else if (((req->flags & SYMLOOK_IN_PLT) == 0) && 4761 (ELF_ST_TYPE(symp->st_info) == STT_FUNC)) 4762 break; 4763 /* fallthrough */ 4764 default: 4765 return (false); 4766 } 4767 if (req->name[0] != strp[0] || strcmp(req->name, strp) != 0) 4768 return (false); 4769 4770 if (req->ventry == NULL) { 4771 if (obj->versyms != NULL) { 4772 verndx = VER_NDX(obj->versyms[symnum]); 4773 if (verndx > obj->vernum) { 4774 _rtld_error( 4775 "%s: symbol %s references wrong version %d", 4776 obj->path, obj->strtab + symnum, verndx); 4777 return (false); 4778 } 4779 /* 4780 * If we are not called from dlsym (i.e. this 4781 * is a normal relocation from unversioned 4782 * binary), accept the symbol immediately if 4783 * it happens to have first version after this 4784 * shared object became versioned. Otherwise, 4785 * if symbol is versioned and not hidden, 4786 * remember it. If it is the only symbol with 4787 * this name exported by the shared object, it 4788 * will be returned as a match by the calling 4789 * function. If symbol is global (verndx < 2) 4790 * accept it unconditionally. 4791 */ 4792 if ((req->flags & SYMLOOK_DLSYM) == 0 && 4793 verndx == VER_NDX_GIVEN) { 4794 result->sym_out = symp; 4795 return (true); 4796 } 4797 else if (verndx >= VER_NDX_GIVEN) { 4798 if ((obj->versyms[symnum] & VER_NDX_HIDDEN) 4799 == 0) { 4800 if (result->vsymp == NULL) 4801 result->vsymp = symp; 4802 result->vcount++; 4803 } 4804 return (false); 4805 } 4806 } 4807 result->sym_out = symp; 4808 return (true); 4809 } 4810 if (obj->versyms == NULL) { 4811 if (object_match_name(obj, req->ventry->name)) { 4812 _rtld_error("%s: object %s should provide version %s " 4813 "for symbol %s", obj_rtld.path, obj->path, 4814 req->ventry->name, obj->strtab + symnum); 4815 return (false); 4816 } 4817 } else { 4818 verndx = VER_NDX(obj->versyms[symnum]); 4819 if (verndx > obj->vernum) { 4820 _rtld_error("%s: symbol %s references wrong version %d", 4821 obj->path, obj->strtab + symnum, verndx); 4822 return (false); 4823 } 4824 if (obj->vertab[verndx].hash != req->ventry->hash || 4825 strcmp(obj->vertab[verndx].name, req->ventry->name)) { 4826 /* 4827 * Version does not match. Look if this is a 4828 * global symbol and if it is not hidden. If 4829 * global symbol (verndx < 2) is available, 4830 * use it. Do not return symbol if we are 4831 * called by dlvsym, because dlvsym looks for 4832 * a specific version and default one is not 4833 * what dlvsym wants. 4834 */ 4835 if ((req->flags & SYMLOOK_DLSYM) || 4836 (verndx >= VER_NDX_GIVEN) || 4837 (obj->versyms[symnum] & VER_NDX_HIDDEN)) 4838 return (false); 4839 } 4840 } 4841 result->sym_out = symp; 4842 return (true); 4843 } 4844 4845 /* 4846 * Search for symbol using SysV hash function. 4847 * obj->buckets is known not to be NULL at this point; the test for this was 4848 * performed with the obj->valid_hash_sysv assignment. 4849 */ 4850 static int 4851 symlook_obj1_sysv(SymLook *req, const Obj_Entry *obj) 4852 { 4853 unsigned long symnum; 4854 Sym_Match_Result matchres; 4855 4856 matchres.sym_out = NULL; 4857 matchres.vsymp = NULL; 4858 matchres.vcount = 0; 4859 4860 for (symnum = obj->buckets[req->hash % obj->nbuckets]; 4861 symnum != STN_UNDEF; symnum = obj->chains[symnum]) { 4862 if (symnum >= obj->nchains) 4863 return (ESRCH); /* Bad object */ 4864 4865 if (matched_symbol(req, obj, &matchres, symnum)) { 4866 req->sym_out = matchres.sym_out; 4867 req->defobj_out = obj; 4868 return (0); 4869 } 4870 } 4871 if (matchres.vcount == 1) { 4872 req->sym_out = matchres.vsymp; 4873 req->defobj_out = obj; 4874 return (0); 4875 } 4876 return (ESRCH); 4877 } 4878 4879 /* Search for symbol using GNU hash function */ 4880 static int 4881 symlook_obj1_gnu(SymLook *req, const Obj_Entry *obj) 4882 { 4883 Elf_Addr bloom_word; 4884 const Elf32_Word *hashval; 4885 Elf32_Word bucket; 4886 Sym_Match_Result matchres; 4887 unsigned int h1, h2; 4888 unsigned long symnum; 4889 4890 matchres.sym_out = NULL; 4891 matchres.vsymp = NULL; 4892 matchres.vcount = 0; 4893 4894 /* Pick right bitmask word from Bloom filter array */ 4895 bloom_word = obj->bloom_gnu[(req->hash_gnu / __ELF_WORD_SIZE) & 4896 obj->maskwords_bm_gnu]; 4897 4898 /* Calculate modulus word size of gnu hash and its derivative */ 4899 h1 = req->hash_gnu & (__ELF_WORD_SIZE - 1); 4900 h2 = ((req->hash_gnu >> obj->shift2_gnu) & (__ELF_WORD_SIZE - 1)); 4901 4902 /* Filter out the "definitely not in set" queries */ 4903 if (((bloom_word >> h1) & (bloom_word >> h2) & 1) == 0) 4904 return (ESRCH); 4905 4906 /* Locate hash chain and corresponding value element*/ 4907 bucket = obj->buckets_gnu[req->hash_gnu % obj->nbuckets_gnu]; 4908 if (bucket == 0) 4909 return (ESRCH); 4910 hashval = &obj->chain_zero_gnu[bucket]; 4911 do { 4912 if (((*hashval ^ req->hash_gnu) >> 1) == 0) { 4913 symnum = hashval - obj->chain_zero_gnu; 4914 if (matched_symbol(req, obj, &matchres, symnum)) { 4915 req->sym_out = matchres.sym_out; 4916 req->defobj_out = obj; 4917 return (0); 4918 } 4919 } 4920 } while ((*hashval++ & 1) == 0); 4921 if (matchres.vcount == 1) { 4922 req->sym_out = matchres.vsymp; 4923 req->defobj_out = obj; 4924 return (0); 4925 } 4926 return (ESRCH); 4927 } 4928 4929 static void 4930 trace_calc_fmts(const char **main_local, const char **fmt1, const char **fmt2) 4931 { 4932 *main_local = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_PROGNAME); 4933 if (*main_local == NULL) 4934 *main_local = ""; 4935 4936 *fmt1 = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_FMT1); 4937 if (*fmt1 == NULL) 4938 *fmt1 = "\t%o => %p (%x)\n"; 4939 4940 *fmt2 = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_FMT2); 4941 if (*fmt2 == NULL) 4942 *fmt2 = "\t%o (%x)\n"; 4943 } 4944 4945 static void 4946 trace_print_obj(Obj_Entry *obj, const char *name, const char *path, 4947 const char *main_local, const char *fmt1, const char *fmt2) 4948 { 4949 const char *fmt; 4950 int c; 4951 4952 if (fmt1 == NULL) 4953 fmt = fmt2; 4954 else 4955 /* XXX bogus */ 4956 fmt = strncmp(name, "lib", 3) == 0 ? fmt1 : fmt2; 4957 4958 while ((c = *fmt++) != '\0') { 4959 switch (c) { 4960 default: 4961 rtld_putchar(c); 4962 continue; 4963 case '\\': 4964 switch (c = *fmt) { 4965 case '\0': 4966 continue; 4967 case 'n': 4968 rtld_putchar('\n'); 4969 break; 4970 case 't': 4971 rtld_putchar('\t'); 4972 break; 4973 } 4974 break; 4975 case '%': 4976 switch (c = *fmt) { 4977 case '\0': 4978 continue; 4979 case '%': 4980 default: 4981 rtld_putchar(c); 4982 break; 4983 case 'A': 4984 rtld_putstr(main_local); 4985 break; 4986 case 'a': 4987 rtld_putstr(obj_main->path); 4988 break; 4989 case 'o': 4990 rtld_putstr(name); 4991 break; 4992 case 'p': 4993 rtld_putstr(path); 4994 break; 4995 case 'x': 4996 rtld_printf("%p", obj != NULL ? 4997 obj->mapbase : NULL); 4998 break; 4999 } 5000 break; 5001 } 5002 ++fmt; 5003 } 5004 } 5005 5006 static void 5007 trace_loaded_objects(Obj_Entry *obj, bool show_preload) 5008 { 5009 const char *fmt1, *fmt2, *main_local; 5010 const char *name, *path; 5011 bool first_spurious, list_containers; 5012 5013 trace_calc_fmts(&main_local, &fmt1, &fmt2); 5014 list_containers = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_ALL) != NULL; 5015 5016 for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 5017 Needed_Entry *needed; 5018 5019 if (obj->marker) 5020 continue; 5021 if (list_containers && obj->needed != NULL) 5022 rtld_printf("%s:\n", obj->path); 5023 for (needed = obj->needed; needed; needed = needed->next) { 5024 if (needed->obj != NULL) { 5025 if (needed->obj->traced && !list_containers) 5026 continue; 5027 needed->obj->traced = true; 5028 path = needed->obj->path; 5029 } else 5030 path = "not found"; 5031 5032 name = obj->strtab + needed->name; 5033 trace_print_obj(needed->obj, name, path, main_local, 5034 fmt1, fmt2); 5035 } 5036 } 5037 5038 if (show_preload) { 5039 if (ld_get_env_var(LD_TRACE_LOADED_OBJECTS_FMT2) == NULL) 5040 fmt2 = "\t%p (%x)\n"; 5041 first_spurious = true; 5042 5043 TAILQ_FOREACH(obj, &obj_list, next) { 5044 if (obj->marker || obj == obj_main || obj->traced) 5045 continue; 5046 5047 if (list_containers && first_spurious) { 5048 rtld_printf("[preloaded]\n"); 5049 first_spurious = false; 5050 } 5051 5052 Name_Entry *fname = STAILQ_FIRST(&obj->names); 5053 name = fname == NULL ? "<unknown>" : fname->name; 5054 trace_print_obj(obj, name, obj->path, main_local, 5055 NULL, fmt2); 5056 } 5057 } 5058 } 5059 5060 /* 5061 * Unload a dlopened object and its dependencies from memory and from 5062 * our data structures. It is assumed that the DAG rooted in the 5063 * object has already been unreferenced, and that the object has a 5064 * reference count of 0. 5065 */ 5066 static void 5067 unload_object(Obj_Entry *root, RtldLockState *lockstate) 5068 { 5069 Obj_Entry marker, *obj, *next; 5070 5071 assert(root->refcount == 0); 5072 5073 /* 5074 * Pass over the DAG removing unreferenced objects from 5075 * appropriate lists. 5076 */ 5077 unlink_object(root); 5078 5079 /* Unmap all objects that are no longer referenced. */ 5080 for (obj = TAILQ_FIRST(&obj_list); obj != NULL; obj = next) { 5081 next = TAILQ_NEXT(obj, next); 5082 if (obj->marker || obj->refcount != 0) 5083 continue; 5084 LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase, 5085 obj->mapsize, 0, obj->path); 5086 dbg("unloading \"%s\"", obj->path); 5087 /* 5088 * Unlink the object now to prevent new references from 5089 * being acquired while the bind lock is dropped in 5090 * recursive dlclose() invocations. 5091 */ 5092 TAILQ_REMOVE(&obj_list, obj, next); 5093 obj_count--; 5094 5095 if (obj->filtees_loaded) { 5096 if (next != NULL) { 5097 init_marker(&marker); 5098 TAILQ_INSERT_BEFORE(next, &marker, next); 5099 unload_filtees(obj, lockstate); 5100 next = TAILQ_NEXT(&marker, next); 5101 TAILQ_REMOVE(&obj_list, &marker, next); 5102 } else 5103 unload_filtees(obj, lockstate); 5104 } 5105 release_object(obj); 5106 } 5107 } 5108 5109 static void 5110 unlink_object(Obj_Entry *root) 5111 { 5112 Objlist_Entry *elm; 5113 5114 if (root->refcount == 0) { 5115 /* Remove the object from the RTLD_GLOBAL list. */ 5116 objlist_remove(&list_global, root); 5117 5118 /* Remove the object from all objects' DAG lists. */ 5119 STAILQ_FOREACH(elm, &root->dagmembers, link) { 5120 objlist_remove(&elm->obj->dldags, root); 5121 if (elm->obj != root) 5122 unlink_object(elm->obj); 5123 } 5124 } 5125 } 5126 5127 static void 5128 ref_dag(Obj_Entry *root) 5129 { 5130 Objlist_Entry *elm; 5131 5132 assert(root->dag_inited); 5133 STAILQ_FOREACH(elm, &root->dagmembers, link) 5134 elm->obj->refcount++; 5135 } 5136 5137 static void 5138 unref_dag(Obj_Entry *root) 5139 { 5140 Objlist_Entry *elm; 5141 5142 assert(root->dag_inited); 5143 STAILQ_FOREACH(elm, &root->dagmembers, link) 5144 elm->obj->refcount--; 5145 } 5146 5147 /* 5148 * Common code for MD __tls_get_addr(). 5149 */ 5150 static void * 5151 tls_get_addr_slow(Elf_Addr **dtvp, int index, size_t offset, bool locked) 5152 { 5153 Elf_Addr *newdtv, *dtv; 5154 RtldLockState lockstate; 5155 int to_copy; 5156 5157 dtv = *dtvp; 5158 /* Check dtv generation in case new modules have arrived */ 5159 if (dtv[0] != tls_dtv_generation) { 5160 if (!locked) 5161 wlock_acquire(rtld_bind_lock, &lockstate); 5162 newdtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 5163 to_copy = dtv[1]; 5164 if (to_copy > tls_max_index) 5165 to_copy = tls_max_index; 5166 memcpy(&newdtv[2], &dtv[2], to_copy * sizeof(Elf_Addr)); 5167 newdtv[0] = tls_dtv_generation; 5168 newdtv[1] = tls_max_index; 5169 free(dtv); 5170 if (!locked) 5171 lock_release(rtld_bind_lock, &lockstate); 5172 dtv = *dtvp = newdtv; 5173 } 5174 5175 /* Dynamically allocate module TLS if necessary */ 5176 if (dtv[index + 1] == 0) { 5177 /* Signal safe, wlock will block out signals. */ 5178 if (!locked) 5179 wlock_acquire(rtld_bind_lock, &lockstate); 5180 if (!dtv[index + 1]) 5181 dtv[index + 1] = (Elf_Addr)allocate_module_tls(index); 5182 if (!locked) 5183 lock_release(rtld_bind_lock, &lockstate); 5184 } 5185 return ((void *)(dtv[index + 1] + offset)); 5186 } 5187 5188 void * 5189 tls_get_addr_common(uintptr_t **dtvp, int index, size_t offset) 5190 { 5191 uintptr_t *dtv; 5192 5193 dtv = *dtvp; 5194 /* Check dtv generation in case new modules have arrived */ 5195 if (__predict_true(dtv[0] == tls_dtv_generation && 5196 dtv[index + 1] != 0)) 5197 return ((void *)(dtv[index + 1] + offset)); 5198 return (tls_get_addr_slow(dtvp, index, offset, false)); 5199 } 5200 5201 #ifdef TLS_VARIANT_I 5202 5203 /* 5204 * Return pointer to allocated TLS block 5205 */ 5206 static void * 5207 get_tls_block_ptr(void *tcb, size_t tcbsize) 5208 { 5209 size_t extra_size, post_size, pre_size, tls_block_size; 5210 size_t tls_init_align; 5211 5212 tls_init_align = MAX(obj_main->tlsalign, 1); 5213 5214 /* Compute fragments sizes. */ 5215 extra_size = tcbsize - TLS_TCB_SIZE; 5216 post_size = calculate_tls_post_size(tls_init_align); 5217 tls_block_size = tcbsize + post_size; 5218 pre_size = roundup2(tls_block_size, tls_init_align) - tls_block_size; 5219 5220 return ((char *)tcb - pre_size - extra_size); 5221 } 5222 5223 /* 5224 * Allocate Static TLS using the Variant I method. 5225 * 5226 * For details on the layout, see lib/libc/gen/tls.c. 5227 * 5228 * NB: rtld's tls_static_space variable includes TLS_TCB_SIZE and post_size as 5229 * it is based on tls_last_offset, and TLS offsets here are really TCB 5230 * offsets, whereas libc's tls_static_space is just the executable's static 5231 * TLS segment. 5232 */ 5233 void * 5234 allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign) 5235 { 5236 Obj_Entry *obj; 5237 char *tls_block; 5238 Elf_Addr *dtv, **tcb; 5239 Elf_Addr addr; 5240 Elf_Addr i; 5241 size_t extra_size, maxalign, post_size, pre_size, tls_block_size; 5242 size_t tls_init_align, tls_init_offset; 5243 5244 if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE) 5245 return (oldtcb); 5246 5247 assert(tcbsize >= TLS_TCB_SIZE); 5248 maxalign = MAX(tcbalign, tls_static_max_align); 5249 tls_init_align = MAX(obj_main->tlsalign, 1); 5250 5251 /* Compute fragmets sizes. */ 5252 extra_size = tcbsize - TLS_TCB_SIZE; 5253 post_size = calculate_tls_post_size(tls_init_align); 5254 tls_block_size = tcbsize + post_size; 5255 pre_size = roundup2(tls_block_size, tls_init_align) - tls_block_size; 5256 tls_block_size += pre_size + tls_static_space - TLS_TCB_SIZE - post_size; 5257 5258 /* Allocate whole TLS block */ 5259 tls_block = malloc_aligned(tls_block_size, maxalign, 0); 5260 tcb = (Elf_Addr **)(tls_block + pre_size + extra_size); 5261 5262 if (oldtcb != NULL) { 5263 memcpy(tls_block, get_tls_block_ptr(oldtcb, tcbsize), 5264 tls_static_space); 5265 free_aligned(get_tls_block_ptr(oldtcb, tcbsize)); 5266 5267 /* Adjust the DTV. */ 5268 dtv = tcb[0]; 5269 for (i = 0; i < dtv[1]; i++) { 5270 if (dtv[i+2] >= (Elf_Addr)oldtcb && 5271 dtv[i+2] < (Elf_Addr)oldtcb + tls_static_space) { 5272 dtv[i+2] = dtv[i+2] - (Elf_Addr)oldtcb + (Elf_Addr)tcb; 5273 } 5274 } 5275 } else { 5276 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 5277 tcb[0] = dtv; 5278 dtv[0] = tls_dtv_generation; 5279 dtv[1] = tls_max_index; 5280 5281 for (obj = globallist_curr(objs); obj != NULL; 5282 obj = globallist_next(obj)) { 5283 if (obj->tlsoffset == 0) 5284 continue; 5285 tls_init_offset = obj->tlspoffset & (obj->tlsalign - 1); 5286 addr = (Elf_Addr)tcb + obj->tlsoffset; 5287 if (tls_init_offset > 0) 5288 memset((void *)addr, 0, tls_init_offset); 5289 if (obj->tlsinitsize > 0) { 5290 memcpy((void *)(addr + tls_init_offset), obj->tlsinit, 5291 obj->tlsinitsize); 5292 } 5293 if (obj->tlssize > obj->tlsinitsize) { 5294 memset((void *)(addr + tls_init_offset + obj->tlsinitsize), 5295 0, obj->tlssize - obj->tlsinitsize - tls_init_offset); 5296 } 5297 dtv[obj->tlsindex + 1] = addr; 5298 } 5299 } 5300 5301 return (tcb); 5302 } 5303 5304 void 5305 free_tls(void *tcb, size_t tcbsize, size_t tcbalign __unused) 5306 { 5307 Elf_Addr *dtv; 5308 Elf_Addr tlsstart, tlsend; 5309 size_t post_size; 5310 size_t dtvsize, i, tls_init_align __unused; 5311 5312 assert(tcbsize >= TLS_TCB_SIZE); 5313 tls_init_align = MAX(obj_main->tlsalign, 1); 5314 5315 /* Compute fragments sizes. */ 5316 post_size = calculate_tls_post_size(tls_init_align); 5317 5318 tlsstart = (Elf_Addr)tcb + TLS_TCB_SIZE + post_size; 5319 tlsend = (Elf_Addr)tcb + tls_static_space; 5320 5321 dtv = *(Elf_Addr **)tcb; 5322 dtvsize = dtv[1]; 5323 for (i = 0; i < dtvsize; i++) { 5324 if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] >= tlsend)) { 5325 free((void*)dtv[i+2]); 5326 } 5327 } 5328 free(dtv); 5329 free_aligned(get_tls_block_ptr(tcb, tcbsize)); 5330 } 5331 5332 #endif /* TLS_VARIANT_I */ 5333 5334 #ifdef TLS_VARIANT_II 5335 5336 /* 5337 * Allocate Static TLS using the Variant II method. 5338 */ 5339 void * 5340 allocate_tls(Obj_Entry *objs, void *oldtls, size_t tcbsize, size_t tcbalign) 5341 { 5342 Obj_Entry *obj; 5343 size_t size, ralign; 5344 char *tls; 5345 Elf_Addr *dtv, *olddtv; 5346 Elf_Addr segbase, oldsegbase, addr; 5347 size_t i; 5348 5349 ralign = tcbalign; 5350 if (tls_static_max_align > ralign) 5351 ralign = tls_static_max_align; 5352 size = roundup(tls_static_space, ralign) + roundup(tcbsize, ralign); 5353 5354 assert(tcbsize >= 2*sizeof(Elf_Addr)); 5355 tls = malloc_aligned(size, ralign, 0 /* XXX */); 5356 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 5357 5358 segbase = (Elf_Addr)(tls + roundup(tls_static_space, ralign)); 5359 ((Elf_Addr *)segbase)[0] = segbase; 5360 ((Elf_Addr *)segbase)[1] = (Elf_Addr) dtv; 5361 5362 dtv[0] = tls_dtv_generation; 5363 dtv[1] = tls_max_index; 5364 5365 if (oldtls) { 5366 /* 5367 * Copy the static TLS block over whole. 5368 */ 5369 oldsegbase = (Elf_Addr) oldtls; 5370 memcpy((void *)(segbase - tls_static_space), 5371 (const void *)(oldsegbase - tls_static_space), 5372 tls_static_space); 5373 5374 /* 5375 * If any dynamic TLS blocks have been created tls_get_addr(), 5376 * move them over. 5377 */ 5378 olddtv = ((Elf_Addr **)oldsegbase)[1]; 5379 for (i = 0; i < olddtv[1]; i++) { 5380 if (olddtv[i + 2] < oldsegbase - size || 5381 olddtv[i + 2] > oldsegbase) { 5382 dtv[i + 2] = olddtv[i + 2]; 5383 olddtv[i + 2] = 0; 5384 } 5385 } 5386 5387 /* 5388 * We assume that this block was the one we created with 5389 * allocate_initial_tls(). 5390 */ 5391 free_tls(oldtls, 2 * sizeof(Elf_Addr), sizeof(Elf_Addr)); 5392 } else { 5393 for (obj = objs; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 5394 if (obj->marker || obj->tlsoffset == 0) 5395 continue; 5396 addr = segbase - obj->tlsoffset; 5397 memset((void *)(addr + obj->tlsinitsize), 5398 0, obj->tlssize - obj->tlsinitsize); 5399 if (obj->tlsinit) { 5400 memcpy((void *)addr, obj->tlsinit, obj->tlsinitsize); 5401 obj->static_tls_copied = true; 5402 } 5403 dtv[obj->tlsindex + 1] = addr; 5404 } 5405 } 5406 5407 return ((void *)segbase); 5408 } 5409 5410 void 5411 free_tls(void *tls, size_t tcbsize __unused, size_t tcbalign) 5412 { 5413 Elf_Addr* dtv; 5414 size_t size, ralign; 5415 int dtvsize, i; 5416 Elf_Addr tlsstart, tlsend; 5417 5418 /* 5419 * Figure out the size of the initial TLS block so that we can 5420 * find stuff which ___tls_get_addr() allocated dynamically. 5421 */ 5422 ralign = tcbalign; 5423 if (tls_static_max_align > ralign) 5424 ralign = tls_static_max_align; 5425 size = roundup(tls_static_space, ralign); 5426 5427 dtv = ((Elf_Addr **)tls)[1]; 5428 dtvsize = dtv[1]; 5429 tlsend = (Elf_Addr)tls; 5430 tlsstart = tlsend - size; 5431 for (i = 0; i < dtvsize; i++) { 5432 if (dtv[i + 2] != 0 && (dtv[i + 2] < tlsstart || 5433 dtv[i + 2] > tlsend)) { 5434 free_aligned((void *)dtv[i + 2]); 5435 } 5436 } 5437 5438 free_aligned((void *)tlsstart); 5439 free((void *)dtv); 5440 } 5441 5442 #endif /* TLS_VARIANT_II */ 5443 5444 /* 5445 * Allocate TLS block for module with given index. 5446 */ 5447 void * 5448 allocate_module_tls(int index) 5449 { 5450 Obj_Entry *obj; 5451 char *p; 5452 5453 TAILQ_FOREACH(obj, &obj_list, next) { 5454 if (obj->marker) 5455 continue; 5456 if (obj->tlsindex == index) 5457 break; 5458 } 5459 if (obj == NULL) { 5460 _rtld_error("Can't find module with TLS index %d", index); 5461 rtld_die(); 5462 } 5463 5464 if (obj->tls_static) { 5465 #ifdef TLS_VARIANT_I 5466 p = (char *)_tcb_get() + obj->tlsoffset + TLS_TCB_SIZE; 5467 #else 5468 p = (char *)_tcb_get() - obj->tlsoffset; 5469 #endif 5470 return (p); 5471 } 5472 5473 obj->tls_dynamic = true; 5474 5475 p = malloc_aligned(obj->tlssize, obj->tlsalign, obj->tlspoffset); 5476 memcpy(p, obj->tlsinit, obj->tlsinitsize); 5477 memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize); 5478 return (p); 5479 } 5480 5481 bool 5482 allocate_tls_offset(Obj_Entry *obj) 5483 { 5484 size_t off; 5485 5486 if (obj->tls_dynamic) 5487 return (false); 5488 5489 if (obj->tls_static) 5490 return (true); 5491 5492 if (obj->tlssize == 0) { 5493 obj->tls_static = true; 5494 return (true); 5495 } 5496 5497 if (tls_last_offset == 0) 5498 off = calculate_first_tls_offset(obj->tlssize, obj->tlsalign, 5499 obj->tlspoffset); 5500 else 5501 off = calculate_tls_offset(tls_last_offset, tls_last_size, 5502 obj->tlssize, obj->tlsalign, obj->tlspoffset); 5503 5504 obj->tlsoffset = off; 5505 #ifdef TLS_VARIANT_I 5506 off += obj->tlssize; 5507 #endif 5508 5509 /* 5510 * If we have already fixed the size of the static TLS block, we 5511 * must stay within that size. When allocating the static TLS, we 5512 * leave a small amount of space spare to be used for dynamically 5513 * loading modules which use static TLS. 5514 */ 5515 if (tls_static_space != 0) { 5516 if (off > tls_static_space) 5517 return (false); 5518 } else if (obj->tlsalign > tls_static_max_align) { 5519 tls_static_max_align = obj->tlsalign; 5520 } 5521 5522 tls_last_offset = off; 5523 tls_last_size = obj->tlssize; 5524 obj->tls_static = true; 5525 5526 return (true); 5527 } 5528 5529 void 5530 free_tls_offset(Obj_Entry *obj) 5531 { 5532 5533 /* 5534 * If we were the last thing to allocate out of the static TLS 5535 * block, we give our space back to the 'allocator'. This is a 5536 * simplistic workaround to allow libGL.so.1 to be loaded and 5537 * unloaded multiple times. 5538 */ 5539 size_t off = obj->tlsoffset; 5540 #ifdef TLS_VARIANT_I 5541 off += obj->tlssize; 5542 #endif 5543 if (off == tls_last_offset) { 5544 tls_last_offset -= obj->tlssize; 5545 tls_last_size = 0; 5546 } 5547 } 5548 5549 void * 5550 _rtld_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign) 5551 { 5552 void *ret; 5553 RtldLockState lockstate; 5554 5555 wlock_acquire(rtld_bind_lock, &lockstate); 5556 ret = allocate_tls(globallist_curr(TAILQ_FIRST(&obj_list)), oldtls, 5557 tcbsize, tcbalign); 5558 lock_release(rtld_bind_lock, &lockstate); 5559 return (ret); 5560 } 5561 5562 void 5563 _rtld_free_tls(void *tcb, size_t tcbsize, size_t tcbalign) 5564 { 5565 RtldLockState lockstate; 5566 5567 wlock_acquire(rtld_bind_lock, &lockstate); 5568 free_tls(tcb, tcbsize, tcbalign); 5569 lock_release(rtld_bind_lock, &lockstate); 5570 } 5571 5572 static void 5573 object_add_name(Obj_Entry *obj, const char *name) 5574 { 5575 Name_Entry *entry; 5576 size_t len; 5577 5578 len = strlen(name); 5579 entry = malloc(sizeof(Name_Entry) + len); 5580 5581 if (entry != NULL) { 5582 strcpy(entry->name, name); 5583 STAILQ_INSERT_TAIL(&obj->names, entry, link); 5584 } 5585 } 5586 5587 static int 5588 object_match_name(const Obj_Entry *obj, const char *name) 5589 { 5590 Name_Entry *entry; 5591 5592 STAILQ_FOREACH(entry, &obj->names, link) { 5593 if (strcmp(name, entry->name) == 0) 5594 return (1); 5595 } 5596 return (0); 5597 } 5598 5599 static Obj_Entry * 5600 locate_dependency(const Obj_Entry *obj, const char *name) 5601 { 5602 const Objlist_Entry *entry; 5603 const Needed_Entry *needed; 5604 5605 STAILQ_FOREACH(entry, &list_main, link) { 5606 if (object_match_name(entry->obj, name)) 5607 return (entry->obj); 5608 } 5609 5610 for (needed = obj->needed; needed != NULL; needed = needed->next) { 5611 if (strcmp(obj->strtab + needed->name, name) == 0 || 5612 (needed->obj != NULL && object_match_name(needed->obj, name))) { 5613 /* 5614 * If there is DT_NEEDED for the name we are looking for, 5615 * we are all set. Note that object might not be found if 5616 * dependency was not loaded yet, so the function can 5617 * return NULL here. This is expected and handled 5618 * properly by the caller. 5619 */ 5620 return (needed->obj); 5621 } 5622 } 5623 _rtld_error("%s: Unexpected inconsistency: dependency %s not found", 5624 obj->path, name); 5625 rtld_die(); 5626 } 5627 5628 static int 5629 check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj, 5630 const Elf_Vernaux *vna) 5631 { 5632 const Elf_Verdef *vd; 5633 const char *vername; 5634 5635 vername = refobj->strtab + vna->vna_name; 5636 vd = depobj->verdef; 5637 if (vd == NULL) { 5638 _rtld_error("%s: version %s required by %s not defined", 5639 depobj->path, vername, refobj->path); 5640 return (-1); 5641 } 5642 for (;;) { 5643 if (vd->vd_version != VER_DEF_CURRENT) { 5644 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 5645 depobj->path, vd->vd_version); 5646 return (-1); 5647 } 5648 if (vna->vna_hash == vd->vd_hash) { 5649 const Elf_Verdaux *aux = (const Elf_Verdaux *) 5650 ((const char *)vd + vd->vd_aux); 5651 if (strcmp(vername, depobj->strtab + aux->vda_name) == 0) 5652 return (0); 5653 } 5654 if (vd->vd_next == 0) 5655 break; 5656 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 5657 } 5658 if (vna->vna_flags & VER_FLG_WEAK) 5659 return (0); 5660 _rtld_error("%s: version %s required by %s not found", 5661 depobj->path, vername, refobj->path); 5662 return (-1); 5663 } 5664 5665 static int 5666 rtld_verify_object_versions(Obj_Entry *obj) 5667 { 5668 const Elf_Verneed *vn; 5669 const Elf_Verdef *vd; 5670 const Elf_Verdaux *vda; 5671 const Elf_Vernaux *vna; 5672 const Obj_Entry *depobj; 5673 int maxvernum, vernum; 5674 5675 if (obj->ver_checked) 5676 return (0); 5677 obj->ver_checked = true; 5678 5679 maxvernum = 0; 5680 /* 5681 * Walk over defined and required version records and figure out 5682 * max index used by any of them. Do very basic sanity checking 5683 * while there. 5684 */ 5685 vn = obj->verneed; 5686 while (vn != NULL) { 5687 if (vn->vn_version != VER_NEED_CURRENT) { 5688 _rtld_error("%s: Unsupported version %d of Elf_Verneed entry", 5689 obj->path, vn->vn_version); 5690 return (-1); 5691 } 5692 vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux); 5693 for (;;) { 5694 vernum = VER_NEED_IDX(vna->vna_other); 5695 if (vernum > maxvernum) 5696 maxvernum = vernum; 5697 if (vna->vna_next == 0) 5698 break; 5699 vna = (const Elf_Vernaux *)((const char *)vna + vna->vna_next); 5700 } 5701 if (vn->vn_next == 0) 5702 break; 5703 vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next); 5704 } 5705 5706 vd = obj->verdef; 5707 while (vd != NULL) { 5708 if (vd->vd_version != VER_DEF_CURRENT) { 5709 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 5710 obj->path, vd->vd_version); 5711 return (-1); 5712 } 5713 vernum = VER_DEF_IDX(vd->vd_ndx); 5714 if (vernum > maxvernum) 5715 maxvernum = vernum; 5716 if (vd->vd_next == 0) 5717 break; 5718 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 5719 } 5720 5721 if (maxvernum == 0) 5722 return (0); 5723 5724 /* 5725 * Store version information in array indexable by version index. 5726 * Verify that object version requirements are satisfied along the 5727 * way. 5728 */ 5729 obj->vernum = maxvernum + 1; 5730 obj->vertab = xcalloc(obj->vernum, sizeof(Ver_Entry)); 5731 5732 vd = obj->verdef; 5733 while (vd != NULL) { 5734 if ((vd->vd_flags & VER_FLG_BASE) == 0) { 5735 vernum = VER_DEF_IDX(vd->vd_ndx); 5736 assert(vernum <= maxvernum); 5737 vda = (const Elf_Verdaux *)((const char *)vd + vd->vd_aux); 5738 obj->vertab[vernum].hash = vd->vd_hash; 5739 obj->vertab[vernum].name = obj->strtab + vda->vda_name; 5740 obj->vertab[vernum].file = NULL; 5741 obj->vertab[vernum].flags = 0; 5742 } 5743 if (vd->vd_next == 0) 5744 break; 5745 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 5746 } 5747 5748 vn = obj->verneed; 5749 while (vn != NULL) { 5750 depobj = locate_dependency(obj, obj->strtab + vn->vn_file); 5751 if (depobj == NULL) 5752 return (-1); 5753 vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux); 5754 for (;;) { 5755 if (check_object_provided_version(obj, depobj, vna)) 5756 return (-1); 5757 vernum = VER_NEED_IDX(vna->vna_other); 5758 assert(vernum <= maxvernum); 5759 obj->vertab[vernum].hash = vna->vna_hash; 5760 obj->vertab[vernum].name = obj->strtab + vna->vna_name; 5761 obj->vertab[vernum].file = obj->strtab + vn->vn_file; 5762 obj->vertab[vernum].flags = (vna->vna_other & VER_NEED_HIDDEN) ? 5763 VER_INFO_HIDDEN : 0; 5764 if (vna->vna_next == 0) 5765 break; 5766 vna = (const Elf_Vernaux *)((const char *)vna + vna->vna_next); 5767 } 5768 if (vn->vn_next == 0) 5769 break; 5770 vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next); 5771 } 5772 return (0); 5773 } 5774 5775 static int 5776 rtld_verify_versions(const Objlist *objlist) 5777 { 5778 Objlist_Entry *entry; 5779 int rc; 5780 5781 rc = 0; 5782 STAILQ_FOREACH(entry, objlist, link) { 5783 /* 5784 * Skip dummy objects or objects that have their version requirements 5785 * already checked. 5786 */ 5787 if (entry->obj->strtab == NULL || entry->obj->vertab != NULL) 5788 continue; 5789 if (rtld_verify_object_versions(entry->obj) == -1) { 5790 rc = -1; 5791 if (ld_tracing == NULL) 5792 break; 5793 } 5794 } 5795 if (rc == 0 || ld_tracing != NULL) 5796 rc = rtld_verify_object_versions(&obj_rtld); 5797 return (rc); 5798 } 5799 5800 const Ver_Entry * 5801 fetch_ventry(const Obj_Entry *obj, unsigned long symnum) 5802 { 5803 Elf_Versym vernum; 5804 5805 if (obj->vertab) { 5806 vernum = VER_NDX(obj->versyms[symnum]); 5807 if (vernum >= obj->vernum) { 5808 _rtld_error("%s: symbol %s has wrong verneed value %d", 5809 obj->path, obj->strtab + symnum, vernum); 5810 } else if (obj->vertab[vernum].hash != 0) { 5811 return (&obj->vertab[vernum]); 5812 } 5813 } 5814 return (NULL); 5815 } 5816 5817 int 5818 _rtld_get_stack_prot(void) 5819 { 5820 5821 return (stack_prot); 5822 } 5823 5824 int 5825 _rtld_is_dlopened(void *arg) 5826 { 5827 Obj_Entry *obj; 5828 RtldLockState lockstate; 5829 int res; 5830 5831 rlock_acquire(rtld_bind_lock, &lockstate); 5832 obj = dlcheck(arg); 5833 if (obj == NULL) 5834 obj = obj_from_addr(arg); 5835 if (obj == NULL) { 5836 _rtld_error("No shared object contains address"); 5837 lock_release(rtld_bind_lock, &lockstate); 5838 return (-1); 5839 } 5840 res = obj->dlopened ? 1 : 0; 5841 lock_release(rtld_bind_lock, &lockstate); 5842 return (res); 5843 } 5844 5845 static int 5846 obj_remap_relro(Obj_Entry *obj, int prot) 5847 { 5848 5849 if (obj->relro_size > 0 && mprotect(obj->relro_page, obj->relro_size, 5850 prot) == -1) { 5851 _rtld_error("%s: Cannot set relro protection to %#x: %s", 5852 obj->path, prot, rtld_strerror(errno)); 5853 return (-1); 5854 } 5855 return (0); 5856 } 5857 5858 static int 5859 obj_disable_relro(Obj_Entry *obj) 5860 { 5861 5862 return (obj_remap_relro(obj, PROT_READ | PROT_WRITE)); 5863 } 5864 5865 static int 5866 obj_enforce_relro(Obj_Entry *obj) 5867 { 5868 5869 return (obj_remap_relro(obj, PROT_READ)); 5870 } 5871 5872 static void 5873 map_stacks_exec(RtldLockState *lockstate) 5874 { 5875 void (*thr_map_stacks_exec)(void); 5876 5877 if ((max_stack_flags & PF_X) == 0 || (stack_prot & PROT_EXEC) != 0) 5878 return; 5879 thr_map_stacks_exec = (void (*)(void))(uintptr_t) 5880 get_program_var_addr("__pthread_map_stacks_exec", lockstate); 5881 if (thr_map_stacks_exec != NULL) { 5882 stack_prot |= PROT_EXEC; 5883 thr_map_stacks_exec(); 5884 } 5885 } 5886 5887 static void 5888 distribute_static_tls(Objlist *list, RtldLockState *lockstate) 5889 { 5890 Objlist_Entry *elm; 5891 Obj_Entry *obj; 5892 void (*distrib)(size_t, void *, size_t, size_t); 5893 5894 distrib = (void (*)(size_t, void *, size_t, size_t))(uintptr_t) 5895 get_program_var_addr("__pthread_distribute_static_tls", lockstate); 5896 if (distrib == NULL) 5897 return; 5898 STAILQ_FOREACH(elm, list, link) { 5899 obj = elm->obj; 5900 if (obj->marker || !obj->tls_static || obj->static_tls_copied) 5901 continue; 5902 distrib(obj->tlsoffset, obj->tlsinit, obj->tlsinitsize, 5903 obj->tlssize); 5904 obj->static_tls_copied = true; 5905 } 5906 } 5907 5908 void 5909 symlook_init(SymLook *dst, const char *name) 5910 { 5911 5912 bzero(dst, sizeof(*dst)); 5913 dst->name = name; 5914 dst->hash = elf_hash(name); 5915 dst->hash_gnu = gnu_hash(name); 5916 } 5917 5918 static void 5919 symlook_init_from_req(SymLook *dst, const SymLook *src) 5920 { 5921 5922 dst->name = src->name; 5923 dst->hash = src->hash; 5924 dst->hash_gnu = src->hash_gnu; 5925 dst->ventry = src->ventry; 5926 dst->flags = src->flags; 5927 dst->defobj_out = NULL; 5928 dst->sym_out = NULL; 5929 dst->lockstate = src->lockstate; 5930 } 5931 5932 static int 5933 open_binary_fd(const char *argv0, bool search_in_path, 5934 const char **binpath_res) 5935 { 5936 char *binpath, *pathenv, *pe, *res1; 5937 const char *res; 5938 int fd; 5939 5940 binpath = NULL; 5941 res = NULL; 5942 if (search_in_path && strchr(argv0, '/') == NULL) { 5943 binpath = xmalloc(PATH_MAX); 5944 pathenv = getenv("PATH"); 5945 if (pathenv == NULL) { 5946 _rtld_error("-p and no PATH environment variable"); 5947 rtld_die(); 5948 } 5949 pathenv = strdup(pathenv); 5950 if (pathenv == NULL) { 5951 _rtld_error("Cannot allocate memory"); 5952 rtld_die(); 5953 } 5954 fd = -1; 5955 errno = ENOENT; 5956 while ((pe = strsep(&pathenv, ":")) != NULL) { 5957 if (strlcpy(binpath, pe, PATH_MAX) >= PATH_MAX) 5958 continue; 5959 if (binpath[0] != '\0' && 5960 strlcat(binpath, "/", PATH_MAX) >= PATH_MAX) 5961 continue; 5962 if (strlcat(binpath, argv0, PATH_MAX) >= PATH_MAX) 5963 continue; 5964 fd = open(binpath, O_RDONLY | O_CLOEXEC | O_VERIFY); 5965 if (fd != -1 || errno != ENOENT) { 5966 res = binpath; 5967 break; 5968 } 5969 } 5970 free(pathenv); 5971 } else { 5972 fd = open(argv0, O_RDONLY | O_CLOEXEC | O_VERIFY); 5973 res = argv0; 5974 } 5975 5976 if (fd == -1) { 5977 _rtld_error("Cannot open %s: %s", argv0, rtld_strerror(errno)); 5978 rtld_die(); 5979 } 5980 if (res != NULL && res[0] != '/') { 5981 res1 = xmalloc(PATH_MAX); 5982 if (realpath(res, res1) != NULL) { 5983 if (res != argv0) 5984 free(__DECONST(char *, res)); 5985 res = res1; 5986 } else { 5987 free(res1); 5988 } 5989 } 5990 *binpath_res = res; 5991 return (fd); 5992 } 5993 5994 /* 5995 * Parse a set of command-line arguments. 5996 */ 5997 static int 5998 parse_args(char* argv[], int argc, bool *use_pathp, int *fdp, 5999 const char **argv0, bool *dir_ignore) 6000 { 6001 const char *arg; 6002 char machine[64]; 6003 size_t sz; 6004 int arglen, fd, i, j, mib[2]; 6005 char opt; 6006 bool seen_b, seen_f; 6007 6008 dbg("Parsing command-line arguments"); 6009 *use_pathp = false; 6010 *fdp = -1; 6011 *dir_ignore = false; 6012 seen_b = seen_f = false; 6013 6014 for (i = 1; i < argc; i++ ) { 6015 arg = argv[i]; 6016 dbg("argv[%d]: '%s'", i, arg); 6017 6018 /* 6019 * rtld arguments end with an explicit "--" or with the first 6020 * non-prefixed argument. 6021 */ 6022 if (strcmp(arg, "--") == 0) { 6023 i++; 6024 break; 6025 } 6026 if (arg[0] != '-') 6027 break; 6028 6029 /* 6030 * All other arguments are single-character options that can 6031 * be combined, so we need to search through `arg` for them. 6032 */ 6033 arglen = strlen(arg); 6034 for (j = 1; j < arglen; j++) { 6035 opt = arg[j]; 6036 if (opt == 'h') { 6037 print_usage(argv[0]); 6038 _exit(0); 6039 } else if (opt == 'b') { 6040 if (seen_f) { 6041 _rtld_error("Both -b and -f specified"); 6042 rtld_die(); 6043 } 6044 if (j != arglen - 1) { 6045 _rtld_error("Invalid options: %s", arg); 6046 rtld_die(); 6047 } 6048 i++; 6049 *argv0 = argv[i]; 6050 seen_b = true; 6051 break; 6052 } else if (opt == 'd') { 6053 *dir_ignore = true; 6054 } else if (opt == 'f') { 6055 if (seen_b) { 6056 _rtld_error("Both -b and -f specified"); 6057 rtld_die(); 6058 } 6059 6060 /* 6061 * -f XX can be used to specify a 6062 * descriptor for the binary named at 6063 * the command line (i.e., the later 6064 * argument will specify the process 6065 * name but the descriptor is what 6066 * will actually be executed). 6067 * 6068 * -f must be the last option in the 6069 * group, e.g., -abcf <fd>. 6070 */ 6071 if (j != arglen - 1) { 6072 _rtld_error("Invalid options: %s", arg); 6073 rtld_die(); 6074 } 6075 i++; 6076 fd = parse_integer(argv[i]); 6077 if (fd == -1) { 6078 _rtld_error( 6079 "Invalid file descriptor: '%s'", 6080 argv[i]); 6081 rtld_die(); 6082 } 6083 *fdp = fd; 6084 seen_f = true; 6085 break; 6086 } else if (opt == 'p') { 6087 *use_pathp = true; 6088 } else if (opt == 'u') { 6089 trust = false; 6090 } else if (opt == 'v') { 6091 machine[0] = '\0'; 6092 mib[0] = CTL_HW; 6093 mib[1] = HW_MACHINE; 6094 sz = sizeof(machine); 6095 sysctl(mib, nitems(mib), machine, &sz, NULL, 0); 6096 ld_elf_hints_path = ld_get_env_var( 6097 LD_ELF_HINTS_PATH); 6098 set_ld_elf_hints_path(); 6099 rtld_printf( 6100 "FreeBSD ld-elf.so.1 %s\n" 6101 "FreeBSD_version %d\n" 6102 "Default lib path %s\n" 6103 "Hints lib path %s\n" 6104 "Env prefix %s\n" 6105 "Default hint file %s\n" 6106 "Hint file %s\n" 6107 "libmap file %s\n", 6108 machine, 6109 __FreeBSD_version, ld_standard_library_path, 6110 gethints(false), 6111 ld_env_prefix, ld_elf_hints_default, 6112 ld_elf_hints_path, 6113 ld_path_libmap_conf); 6114 _exit(0); 6115 } else { 6116 _rtld_error("Invalid argument: '%s'", arg); 6117 print_usage(argv[0]); 6118 rtld_die(); 6119 } 6120 } 6121 } 6122 6123 if (!seen_b) 6124 *argv0 = argv[i]; 6125 return (i); 6126 } 6127 6128 /* 6129 * Parse a file descriptor number without pulling in more of libc (e.g. atoi). 6130 */ 6131 static int 6132 parse_integer(const char *str) 6133 { 6134 static const int RADIX = 10; /* XXXJA: possibly support hex? */ 6135 const char *orig; 6136 int n; 6137 char c; 6138 6139 orig = str; 6140 n = 0; 6141 for (c = *str; c != '\0'; c = *++str) { 6142 if (c < '0' || c > '9') 6143 return (-1); 6144 6145 n *= RADIX; 6146 n += c - '0'; 6147 } 6148 6149 /* Make sure we actually parsed something. */ 6150 if (str == orig) 6151 return (-1); 6152 return (n); 6153 } 6154 6155 static void 6156 print_usage(const char *argv0) 6157 { 6158 6159 rtld_printf( 6160 "Usage: %s [-h] [-b <exe>] [-d] [-f <FD>] [-p] [--] <binary> [<args>]\n" 6161 "\n" 6162 "Options:\n" 6163 " -h Display this help message\n" 6164 " -b <exe> Execute <exe> instead of <binary>, arg0 is <binary>\n" 6165 " -d Ignore lack of exec permissions for the binary\n" 6166 " -f <FD> Execute <FD> instead of searching for <binary>\n" 6167 " -p Search in PATH for named binary\n" 6168 " -u Ignore LD_ environment variables\n" 6169 " -v Display identification information\n" 6170 " -- End of RTLD options\n" 6171 " <binary> Name of process to execute\n" 6172 " <args> Arguments to the executed process\n", argv0); 6173 } 6174 6175 #define AUXFMT(at, xfmt) [at] = { .name = #at, .fmt = xfmt } 6176 static const struct auxfmt { 6177 const char *name; 6178 const char *fmt; 6179 } auxfmts[] = { 6180 AUXFMT(AT_NULL, NULL), 6181 AUXFMT(AT_IGNORE, NULL), 6182 AUXFMT(AT_EXECFD, "%ld"), 6183 AUXFMT(AT_PHDR, "%p"), 6184 AUXFMT(AT_PHENT, "%lu"), 6185 AUXFMT(AT_PHNUM, "%lu"), 6186 AUXFMT(AT_PAGESZ, "%lu"), 6187 AUXFMT(AT_BASE, "%#lx"), 6188 AUXFMT(AT_FLAGS, "%#lx"), 6189 AUXFMT(AT_ENTRY, "%p"), 6190 AUXFMT(AT_NOTELF, NULL), 6191 AUXFMT(AT_UID, "%ld"), 6192 AUXFMT(AT_EUID, "%ld"), 6193 AUXFMT(AT_GID, "%ld"), 6194 AUXFMT(AT_EGID, "%ld"), 6195 AUXFMT(AT_EXECPATH, "%s"), 6196 AUXFMT(AT_CANARY, "%p"), 6197 AUXFMT(AT_CANARYLEN, "%lu"), 6198 AUXFMT(AT_OSRELDATE, "%lu"), 6199 AUXFMT(AT_NCPUS, "%lu"), 6200 AUXFMT(AT_PAGESIZES, "%p"), 6201 AUXFMT(AT_PAGESIZESLEN, "%lu"), 6202 AUXFMT(AT_TIMEKEEP, "%p"), 6203 AUXFMT(AT_STACKPROT, "%#lx"), 6204 AUXFMT(AT_EHDRFLAGS, "%#lx"), 6205 AUXFMT(AT_HWCAP, "%#lx"), 6206 AUXFMT(AT_HWCAP2, "%#lx"), 6207 AUXFMT(AT_BSDFLAGS, "%#lx"), 6208 AUXFMT(AT_ARGC, "%lu"), 6209 AUXFMT(AT_ARGV, "%p"), 6210 AUXFMT(AT_ENVC, "%p"), 6211 AUXFMT(AT_ENVV, "%p"), 6212 AUXFMT(AT_PS_STRINGS, "%p"), 6213 AUXFMT(AT_FXRNG, "%p"), 6214 AUXFMT(AT_KPRELOAD, "%p"), 6215 AUXFMT(AT_USRSTACKBASE, "%#lx"), 6216 AUXFMT(AT_USRSTACKLIM, "%#lx"), 6217 }; 6218 6219 static bool 6220 is_ptr_fmt(const char *fmt) 6221 { 6222 char last; 6223 6224 last = fmt[strlen(fmt) - 1]; 6225 return (last == 'p' || last == 's'); 6226 } 6227 6228 static void 6229 dump_auxv(Elf_Auxinfo **aux_info) 6230 { 6231 Elf_Auxinfo *auxp; 6232 const struct auxfmt *fmt; 6233 int i; 6234 6235 for (i = 0; i < AT_COUNT; i++) { 6236 auxp = aux_info[i]; 6237 if (auxp == NULL) 6238 continue; 6239 fmt = &auxfmts[i]; 6240 if (fmt->fmt == NULL) 6241 continue; 6242 rtld_fdprintf(STDOUT_FILENO, "%s:\t", fmt->name); 6243 if (is_ptr_fmt(fmt->fmt)) { 6244 rtld_fdprintfx(STDOUT_FILENO, fmt->fmt, 6245 auxp->a_un.a_ptr); 6246 } else { 6247 rtld_fdprintfx(STDOUT_FILENO, fmt->fmt, 6248 auxp->a_un.a_val); 6249 } 6250 rtld_fdprintf(STDOUT_FILENO, "\n"); 6251 } 6252 } 6253 6254 /* 6255 * Overrides for libc_pic-provided functions. 6256 */ 6257 6258 int 6259 __getosreldate(void) 6260 { 6261 size_t len; 6262 int oid[2]; 6263 int error, osrel; 6264 6265 if (osreldate != 0) 6266 return (osreldate); 6267 6268 oid[0] = CTL_KERN; 6269 oid[1] = KERN_OSRELDATE; 6270 osrel = 0; 6271 len = sizeof(osrel); 6272 error = sysctl(oid, 2, &osrel, &len, NULL, 0); 6273 if (error == 0 && osrel > 0 && len == sizeof(osrel)) 6274 osreldate = osrel; 6275 return (osreldate); 6276 } 6277 const char * 6278 rtld_strerror(int errnum) 6279 { 6280 6281 if (errnum < 0 || errnum >= sys_nerr) 6282 return ("Unknown error"); 6283 return (sys_errlist[errnum]); 6284 } 6285 6286 char * 6287 getenv(const char *name) 6288 { 6289 return (__DECONST(char *, rtld_get_env_val(environ, name, 6290 strlen(name)))); 6291 } 6292 6293 /* malloc */ 6294 void * 6295 malloc(size_t nbytes) 6296 { 6297 6298 return (__crt_malloc(nbytes)); 6299 } 6300 6301 void * 6302 calloc(size_t num, size_t size) 6303 { 6304 6305 return (__crt_calloc(num, size)); 6306 } 6307 6308 void 6309 free(void *cp) 6310 { 6311 6312 __crt_free(cp); 6313 } 6314 6315 void * 6316 realloc(void *cp, size_t nbytes) 6317 { 6318 6319 return (__crt_realloc(cp, nbytes)); 6320 } 6321 6322 extern int _rtld_version__FreeBSD_version __exported; 6323 int _rtld_version__FreeBSD_version = __FreeBSD_version; 6324 6325 extern char _rtld_version_laddr_offset __exported; 6326 char _rtld_version_laddr_offset; 6327 6328 extern char _rtld_version_dlpi_tls_data __exported; 6329 char _rtld_version_dlpi_tls_data; 6330