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 #include <sys/param.h> 43 #include <sys/mount.h> 44 #include <sys/mman.h> 45 #include <sys/stat.h> 46 #include <sys/sysctl.h> 47 #include <sys/uio.h> 48 #include <sys/utsname.h> 49 #include <sys/ktrace.h> 50 51 #include <dlfcn.h> 52 #include <err.h> 53 #include <errno.h> 54 #include <fcntl.h> 55 #include <stdarg.h> 56 #include <stdio.h> 57 #include <stdlib.h> 58 #include <string.h> 59 #include <unistd.h> 60 61 #include "debug.h" 62 #include "rtld.h" 63 #include "libmap.h" 64 #include "rtld_paths.h" 65 #include "rtld_tls.h" 66 #include "rtld_printf.h" 67 #include "rtld_malloc.h" 68 #include "rtld_utrace.h" 69 #include "notes.h" 70 #include "rtld_libc.h" 71 72 /* Types. */ 73 typedef void (*func_ptr_type)(void); 74 typedef void * (*path_enum_proc) (const char *path, size_t len, void *arg); 75 76 77 /* Variables that cannot be static: */ 78 extern struct r_debug r_debug; /* For GDB */ 79 extern int _thread_autoinit_dummy_decl; 80 extern void (*__cleanup)(void); 81 82 struct dlerror_save { 83 int seen; 84 char *msg; 85 }; 86 87 /* 88 * Function declarations. 89 */ 90 static const char *basename(const char *); 91 static void digest_dynamic1(Obj_Entry *, int, const Elf_Dyn **, 92 const Elf_Dyn **, const Elf_Dyn **); 93 static bool digest_dynamic2(Obj_Entry *, const Elf_Dyn *, const Elf_Dyn *, 94 const Elf_Dyn *); 95 static bool digest_dynamic(Obj_Entry *, int); 96 static Obj_Entry *digest_phdr(const Elf_Phdr *, int, caddr_t, const char *); 97 static void distribute_static_tls(Objlist *, RtldLockState *); 98 static Obj_Entry *dlcheck(void *); 99 static int dlclose_locked(void *, RtldLockState *); 100 static Obj_Entry *dlopen_object(const char *name, int fd, Obj_Entry *refobj, 101 int lo_flags, int mode, RtldLockState *lockstate); 102 static Obj_Entry *do_load_object(int, const char *, char *, struct stat *, int); 103 static int do_search_info(const Obj_Entry *obj, int, struct dl_serinfo *); 104 static bool donelist_check(DoneList *, const Obj_Entry *); 105 static void dump_auxv(Elf_Auxinfo **aux_info); 106 static void errmsg_restore(struct dlerror_save *); 107 static struct dlerror_save *errmsg_save(void); 108 static void *fill_search_info(const char *, size_t, void *); 109 static char *find_library(const char *, const Obj_Entry *, int *); 110 static const char *gethints(bool); 111 static void hold_object(Obj_Entry *); 112 static void unhold_object(Obj_Entry *); 113 static void init_dag(Obj_Entry *); 114 static void init_marker(Obj_Entry *); 115 static void init_pagesizes(Elf_Auxinfo **aux_info); 116 static void init_rtld(caddr_t, Elf_Auxinfo **); 117 static void initlist_add_neededs(Needed_Entry *, Objlist *); 118 static void initlist_add_objects(Obj_Entry *, Obj_Entry *, Objlist *); 119 static int initlist_objects_ifunc(Objlist *, bool, int, RtldLockState *); 120 static void linkmap_add(Obj_Entry *); 121 static void linkmap_delete(Obj_Entry *); 122 static void load_filtees(Obj_Entry *, int flags, RtldLockState *); 123 static void unload_filtees(Obj_Entry *, RtldLockState *); 124 static int load_needed_objects(Obj_Entry *, int); 125 static int load_preload_objects(const char *, bool); 126 static int load_kpreload(const void *addr); 127 static Obj_Entry *load_object(const char *, int fd, const Obj_Entry *, int); 128 static void map_stacks_exec(RtldLockState *); 129 static int obj_disable_relro(Obj_Entry *); 130 static int obj_enforce_relro(Obj_Entry *); 131 static void objlist_call_fini(Objlist *, Obj_Entry *, RtldLockState *); 132 static void objlist_call_init(Objlist *, RtldLockState *); 133 static void objlist_clear(Objlist *); 134 static Objlist_Entry *objlist_find(Objlist *, const Obj_Entry *); 135 static void objlist_init(Objlist *); 136 static void objlist_push_head(Objlist *, Obj_Entry *); 137 static void objlist_push_tail(Objlist *, Obj_Entry *); 138 static void objlist_put_after(Objlist *, Obj_Entry *, Obj_Entry *); 139 static void objlist_remove(Objlist *, Obj_Entry *); 140 static int open_binary_fd(const char *argv0, bool search_in_path, 141 const char **binpath_res); 142 static int parse_args(char* argv[], int argc, bool *use_pathp, int *fdp, 143 const char **argv0, bool *dir_ignore); 144 static int parse_integer(const char *); 145 static void *path_enumerate(const char *, path_enum_proc, const char *, void *); 146 static void print_usage(const char *argv0); 147 static void release_object(Obj_Entry *); 148 static int relocate_object_dag(Obj_Entry *root, bool bind_now, 149 Obj_Entry *rtldobj, int flags, RtldLockState *lockstate); 150 static int relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, 151 int flags, RtldLockState *lockstate); 152 static int relocate_objects(Obj_Entry *, bool, Obj_Entry *, int, 153 RtldLockState *); 154 static int resolve_object_ifunc(Obj_Entry *, bool, int, RtldLockState *); 155 static int rtld_dirname(const char *, char *); 156 static int rtld_dirname_abs(const char *, char *); 157 static void *rtld_dlopen(const char *name, int fd, int mode); 158 static void rtld_exit(void); 159 static void rtld_nop_exit(void); 160 static char *search_library_path(const char *, const char *, const char *, 161 int *); 162 static char *search_library_pathfds(const char *, const char *, int *); 163 static const void **get_program_var_addr(const char *, RtldLockState *); 164 static void set_program_var(const char *, const void *); 165 static int symlook_default(SymLook *, const Obj_Entry *refobj); 166 static int symlook_global(SymLook *, DoneList *); 167 static void symlook_init_from_req(SymLook *, const SymLook *); 168 static int symlook_list(SymLook *, const Objlist *, DoneList *); 169 static int symlook_needed(SymLook *, const Needed_Entry *, DoneList *); 170 static int symlook_obj1_sysv(SymLook *, const Obj_Entry *); 171 static int symlook_obj1_gnu(SymLook *, const Obj_Entry *); 172 static void *tls_get_addr_slow(Elf_Addr **, int, size_t, bool) __noinline; 173 static void trace_loaded_objects(Obj_Entry *, bool); 174 static void unlink_object(Obj_Entry *); 175 static void unload_object(Obj_Entry *, RtldLockState *lockstate); 176 static void unref_dag(Obj_Entry *); 177 static void ref_dag(Obj_Entry *); 178 static char *origin_subst_one(Obj_Entry *, char *, const char *, 179 const char *, bool); 180 static char *origin_subst(Obj_Entry *, const char *); 181 static bool obj_resolve_origin(Obj_Entry *obj); 182 static void preinit_main(void); 183 static int rtld_verify_versions(const Objlist *); 184 static int rtld_verify_object_versions(Obj_Entry *); 185 static void object_add_name(Obj_Entry *, const char *); 186 static int object_match_name(const Obj_Entry *, const char *); 187 static void ld_utrace_log(int, void *, void *, size_t, int, const char *); 188 static void rtld_fill_dl_phdr_info(const Obj_Entry *obj, 189 struct dl_phdr_info *phdr_info); 190 static uint32_t gnu_hash(const char *); 191 static bool matched_symbol(SymLook *, const Obj_Entry *, Sym_Match_Result *, 192 const unsigned long); 193 194 void r_debug_state(struct r_debug *, struct link_map *) __noinline __exported; 195 void _r_debug_postinit(struct link_map *) __noinline __exported; 196 197 int __sys_openat(int, const char *, int, ...); 198 199 /* 200 * Data declarations. 201 */ 202 struct r_debug r_debug __exported; /* for GDB; */ 203 static bool libmap_disable; /* Disable libmap */ 204 static bool ld_loadfltr; /* Immediate filters processing */ 205 static const char *libmap_override;/* Maps to use in addition to libmap.conf */ 206 static bool trust; /* False for setuid and setgid programs */ 207 static bool dangerous_ld_env; /* True if environment variables have been 208 used to affect the libraries loaded */ 209 bool ld_bind_not; /* Disable PLT update */ 210 static const char *ld_bind_now; /* Environment variable for immediate binding */ 211 static const char *ld_debug; /* Environment variable for debugging */ 212 static bool ld_dynamic_weak = true; /* True if non-weak definition overrides 213 weak definition */ 214 static const char *ld_library_path;/* Environment variable for search path */ 215 static const char *ld_library_dirs;/* Environment variable for library descriptors */ 216 static const char *ld_preload; /* Environment variable for libraries to 217 load first */ 218 static const char *ld_preload_fds;/* Environment variable for libraries represented by 219 descriptors */ 220 static const char *ld_elf_hints_path; /* Environment variable for alternative hints path */ 221 static const char *ld_tracing; /* Called from ldd to print libs */ 222 static const char *ld_utrace; /* Use utrace() to log events. */ 223 static struct obj_entry_q obj_list; /* Queue of all loaded objects */ 224 static Obj_Entry *obj_main; /* The main program shared object */ 225 static Obj_Entry obj_rtld; /* The dynamic linker shared object */ 226 static unsigned int obj_count; /* Number of objects in obj_list */ 227 static unsigned int obj_loads; /* Number of loads of objects (gen count) */ 228 229 static Objlist list_global = /* Objects dlopened with RTLD_GLOBAL */ 230 STAILQ_HEAD_INITIALIZER(list_global); 231 static Objlist list_main = /* Objects loaded at program startup */ 232 STAILQ_HEAD_INITIALIZER(list_main); 233 static Objlist list_fini = /* Objects needing fini() calls */ 234 STAILQ_HEAD_INITIALIZER(list_fini); 235 236 Elf_Sym sym_zero; /* For resolving undefined weak refs. */ 237 238 #define GDB_STATE(s,m) r_debug.r_state = s; r_debug_state(&r_debug,m); 239 240 extern Elf_Dyn _DYNAMIC; 241 #pragma weak _DYNAMIC 242 243 int dlclose(void *) __exported; 244 char *dlerror(void) __exported; 245 void *dlopen(const char *, int) __exported; 246 void *fdlopen(int, int) __exported; 247 void *dlsym(void *, const char *) __exported; 248 dlfunc_t dlfunc(void *, const char *) __exported; 249 void *dlvsym(void *, const char *, const char *) __exported; 250 int dladdr(const void *, Dl_info *) __exported; 251 void dllockinit(void *, void *(*)(void *), void (*)(void *), void (*)(void *), 252 void (*)(void *), void (*)(void *), void (*)(void *)) __exported; 253 int dlinfo(void *, int , void *) __exported; 254 int dl_iterate_phdr(__dl_iterate_hdr_callback, void *) __exported; 255 int _rtld_addr_phdr(const void *, struct dl_phdr_info *) __exported; 256 int _rtld_get_stack_prot(void) __exported; 257 int _rtld_is_dlopened(void *) __exported; 258 void _rtld_error(const char *, ...) __exported; 259 260 /* Only here to fix -Wmissing-prototypes warnings */ 261 int __getosreldate(void); 262 func_ptr_type _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp); 263 Elf_Addr _rtld_bind(Obj_Entry *obj, Elf_Size reloff); 264 265 int npagesizes; 266 static int osreldate; 267 size_t *pagesizes; 268 size_t page_size; 269 270 static int stack_prot = PROT_READ | PROT_WRITE | PROT_EXEC; 271 static int max_stack_flags; 272 273 /* 274 * Global declarations normally provided by crt1. The dynamic linker is 275 * not built with crt1, so we have to provide them ourselves. 276 */ 277 char *__progname; 278 char **environ; 279 280 /* 281 * Used to pass argc, argv to init functions. 282 */ 283 int main_argc; 284 char **main_argv; 285 286 /* 287 * Globals to control TLS allocation. 288 */ 289 size_t tls_last_offset; /* Static TLS offset of last module */ 290 size_t tls_last_size; /* Static TLS size of last module */ 291 size_t tls_static_space; /* Static TLS space allocated */ 292 static size_t tls_static_max_align; 293 Elf_Addr tls_dtv_generation = 1; /* Used to detect when dtv size changes */ 294 int tls_max_index = 1; /* Largest module index allocated */ 295 296 static bool ld_library_path_rpath = false; 297 bool ld_fast_sigblock = false; 298 299 /* 300 * Globals for path names, and such 301 */ 302 const char *ld_elf_hints_default = _PATH_ELF_HINTS; 303 const char *ld_path_libmap_conf = _PATH_LIBMAP_CONF; 304 const char *ld_path_rtld = _PATH_RTLD; 305 const char *ld_standard_library_path = STANDARD_LIBRARY_PATH; 306 const char *ld_env_prefix = LD_; 307 308 static void (*rtld_exit_ptr)(void); 309 310 /* 311 * Fill in a DoneList with an allocation large enough to hold all of 312 * the currently-loaded objects. Keep this as a macro since it calls 313 * alloca and we want that to occur within the scope of the caller. 314 */ 315 #define donelist_init(dlp) \ 316 ((dlp)->objs = alloca(obj_count * sizeof (dlp)->objs[0]), \ 317 assert((dlp)->objs != NULL), \ 318 (dlp)->num_alloc = obj_count, \ 319 (dlp)->num_used = 0) 320 321 #define LD_UTRACE(e, h, mb, ms, r, n) do { \ 322 if (ld_utrace != NULL) \ 323 ld_utrace_log(e, h, mb, ms, r, n); \ 324 } while (0) 325 326 static void 327 ld_utrace_log(int event, void *handle, void *mapbase, size_t mapsize, 328 int refcnt, const char *name) 329 { 330 struct utrace_rtld ut; 331 static const char rtld_utrace_sig[RTLD_UTRACE_SIG_SZ] = RTLD_UTRACE_SIG; 332 333 memcpy(ut.sig, rtld_utrace_sig, sizeof(ut.sig)); 334 ut.event = event; 335 ut.handle = handle; 336 ut.mapbase = mapbase; 337 ut.mapsize = mapsize; 338 ut.refcnt = refcnt; 339 bzero(ut.name, sizeof(ut.name)); 340 if (name) 341 strlcpy(ut.name, name, sizeof(ut.name)); 342 utrace(&ut, sizeof(ut)); 343 } 344 345 enum { 346 LD_BIND_NOW = 0, 347 LD_PRELOAD, 348 LD_LIBMAP, 349 LD_LIBRARY_PATH, 350 LD_LIBRARY_PATH_FDS, 351 LD_LIBMAP_DISABLE, 352 LD_BIND_NOT, 353 LD_DEBUG, 354 LD_ELF_HINTS_PATH, 355 LD_LOADFLTR, 356 LD_LIBRARY_PATH_RPATH, 357 LD_PRELOAD_FDS, 358 LD_DYNAMIC_WEAK, 359 LD_TRACE_LOADED_OBJECTS, 360 LD_UTRACE, 361 LD_DUMP_REL_PRE, 362 LD_DUMP_REL_POST, 363 LD_TRACE_LOADED_OBJECTS_PROGNAME, 364 LD_TRACE_LOADED_OBJECTS_FMT1, 365 LD_TRACE_LOADED_OBJECTS_FMT2, 366 LD_TRACE_LOADED_OBJECTS_ALL, 367 LD_SHOW_AUXV, 368 }; 369 370 struct ld_env_var_desc { 371 const char * const n; 372 const char *val; 373 const bool unsecure; 374 }; 375 #define LD_ENV_DESC(var, unsec) \ 376 [LD_##var] = { .n = #var, .unsecure = unsec } 377 378 static struct ld_env_var_desc ld_env_vars[] = { 379 LD_ENV_DESC(BIND_NOW, false), 380 LD_ENV_DESC(PRELOAD, true), 381 LD_ENV_DESC(LIBMAP, true), 382 LD_ENV_DESC(LIBRARY_PATH, true), 383 LD_ENV_DESC(LIBRARY_PATH_FDS, true), 384 LD_ENV_DESC(LIBMAP_DISABLE, true), 385 LD_ENV_DESC(BIND_NOT, true), 386 LD_ENV_DESC(DEBUG, true), 387 LD_ENV_DESC(ELF_HINTS_PATH, true), 388 LD_ENV_DESC(LOADFLTR, true), 389 LD_ENV_DESC(LIBRARY_PATH_RPATH, true), 390 LD_ENV_DESC(PRELOAD_FDS, true), 391 LD_ENV_DESC(DYNAMIC_WEAK, true), 392 LD_ENV_DESC(TRACE_LOADED_OBJECTS, false), 393 LD_ENV_DESC(UTRACE, false), 394 LD_ENV_DESC(DUMP_REL_PRE, false), 395 LD_ENV_DESC(DUMP_REL_POST, false), 396 LD_ENV_DESC(TRACE_LOADED_OBJECTS_PROGNAME, false), 397 LD_ENV_DESC(TRACE_LOADED_OBJECTS_FMT1, false), 398 LD_ENV_DESC(TRACE_LOADED_OBJECTS_FMT2, false), 399 LD_ENV_DESC(TRACE_LOADED_OBJECTS_ALL, false), 400 LD_ENV_DESC(SHOW_AUXV, false), 401 }; 402 403 static const char * 404 ld_get_env_var(int idx) 405 { 406 return (ld_env_vars[idx].val); 407 } 408 409 static const char * 410 rtld_get_env_val(char **env, const char *name, size_t name_len) 411 { 412 char **m, *n, *v; 413 414 for (m = env; *m != NULL; m++) { 415 n = *m; 416 v = strchr(n, '='); 417 if (v == NULL) { 418 /* corrupt environment? */ 419 continue; 420 } 421 if (v - n == (ptrdiff_t)name_len && 422 strncmp(name, n, name_len) == 0) 423 return (v + 1); 424 } 425 return (NULL); 426 } 427 428 static void 429 rtld_init_env_vars_for_prefix(char **env, const char *env_prefix) 430 { 431 struct ld_env_var_desc *lvd; 432 size_t prefix_len, nlen; 433 char **m, *n, *v; 434 int i; 435 436 prefix_len = strlen(env_prefix); 437 for (m = env; *m != NULL; m++) { 438 n = *m; 439 if (strncmp(env_prefix, n, prefix_len) != 0) { 440 /* Not a rtld environment variable. */ 441 continue; 442 } 443 n += prefix_len; 444 v = strchr(n, '='); 445 if (v == NULL) { 446 /* corrupt environment? */ 447 continue; 448 } 449 for (i = 0; i < (int)nitems(ld_env_vars); i++) { 450 lvd = &ld_env_vars[i]; 451 if (lvd->val != NULL) { 452 /* Saw higher-priority variable name already. */ 453 continue; 454 } 455 nlen = strlen(lvd->n); 456 if (v - n == (ptrdiff_t)nlen && 457 strncmp(lvd->n, n, nlen) == 0) { 458 lvd->val = v + 1; 459 break; 460 } 461 } 462 } 463 } 464 465 static void 466 rtld_init_env_vars(char **env) 467 { 468 rtld_init_env_vars_for_prefix(env, ld_env_prefix); 469 } 470 471 static void 472 set_ld_elf_hints_path(void) 473 { 474 if (ld_elf_hints_path == NULL || strlen(ld_elf_hints_path) == 0) 475 ld_elf_hints_path = ld_elf_hints_default; 476 } 477 478 uintptr_t 479 rtld_round_page(uintptr_t x) 480 { 481 return (roundup2(x, page_size)); 482 } 483 484 uintptr_t 485 rtld_trunc_page(uintptr_t x) 486 { 487 return (rounddown2(x, page_size)); 488 } 489 490 /* 491 * Main entry point for dynamic linking. The first argument is the 492 * stack pointer. The stack is expected to be laid out as described 493 * in the SVR4 ABI specification, Intel 386 Processor Supplement. 494 * Specifically, the stack pointer points to a word containing 495 * ARGC. Following that in the stack is a null-terminated sequence 496 * of pointers to argument strings. Then comes a null-terminated 497 * sequence of pointers to environment strings. Finally, there is a 498 * sequence of "auxiliary vector" entries. 499 * 500 * The second argument points to a place to store the dynamic linker's 501 * exit procedure pointer and the third to a place to store the main 502 * program's object. 503 * 504 * The return value is the main program's entry point. 505 */ 506 func_ptr_type 507 _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp) 508 { 509 Elf_Auxinfo *aux, *auxp, *auxpf, *aux_info[AT_COUNT]; 510 Objlist_Entry *entry; 511 Obj_Entry *last_interposer, *obj, *preload_tail; 512 const Elf_Phdr *phdr; 513 Objlist initlist; 514 RtldLockState lockstate; 515 struct stat st; 516 Elf_Addr *argcp; 517 char **argv, **env, **envp, *kexecpath; 518 const char *argv0, *binpath, *library_path_rpath; 519 struct ld_env_var_desc *lvd; 520 caddr_t imgentry; 521 char buf[MAXPATHLEN]; 522 int argc, fd, i, mib[4], old_osrel, osrel, phnum, rtld_argc; 523 size_t sz; 524 #ifdef __powerpc__ 525 int old_auxv_format = 1; 526 #endif 527 bool dir_enable, dir_ignore, direct_exec, explicit_fd, search_in_path; 528 529 /* 530 * On entry, the dynamic linker itself has not been relocated yet. 531 * Be very careful not to reference any global data until after 532 * init_rtld has returned. It is OK to reference file-scope statics 533 * and string constants, and to call static and global functions. 534 */ 535 536 /* Find the auxiliary vector on the stack. */ 537 argcp = sp; 538 argc = *sp++; 539 argv = (char **) sp; 540 sp += argc + 1; /* Skip over arguments and NULL terminator */ 541 env = (char **) sp; 542 while (*sp++ != 0) /* Skip over environment, and NULL terminator */ 543 ; 544 aux = (Elf_Auxinfo *) sp; 545 546 /* Digest the auxiliary vector. */ 547 for (i = 0; i < AT_COUNT; i++) 548 aux_info[i] = NULL; 549 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) { 550 if (auxp->a_type < AT_COUNT) 551 aux_info[auxp->a_type] = auxp; 552 #ifdef __powerpc__ 553 if (auxp->a_type == 23) /* AT_STACKPROT */ 554 old_auxv_format = 0; 555 #endif 556 } 557 558 #ifdef __powerpc__ 559 if (old_auxv_format) { 560 /* Remap from old-style auxv numbers. */ 561 aux_info[23] = aux_info[21]; /* AT_STACKPROT */ 562 aux_info[21] = aux_info[19]; /* AT_PAGESIZESLEN */ 563 aux_info[19] = aux_info[17]; /* AT_NCPUS */ 564 aux_info[17] = aux_info[15]; /* AT_CANARYLEN */ 565 aux_info[15] = aux_info[13]; /* AT_EXECPATH */ 566 aux_info[13] = NULL; /* AT_GID */ 567 568 aux_info[20] = aux_info[18]; /* AT_PAGESIZES */ 569 aux_info[18] = aux_info[16]; /* AT_OSRELDATE */ 570 aux_info[16] = aux_info[14]; /* AT_CANARY */ 571 aux_info[14] = NULL; /* AT_EGID */ 572 } 573 #endif 574 575 /* Initialize and relocate ourselves. */ 576 assert(aux_info[AT_BASE] != NULL); 577 init_rtld((caddr_t) aux_info[AT_BASE]->a_un.a_ptr, aux_info); 578 579 dlerror_dflt_init(); 580 581 __progname = obj_rtld.path; 582 argv0 = argv[0] != NULL ? argv[0] : "(null)"; 583 environ = env; 584 main_argc = argc; 585 main_argv = argv; 586 587 if (aux_info[AT_BSDFLAGS] != NULL && 588 (aux_info[AT_BSDFLAGS]->a_un.a_val & ELF_BSDF_SIGFASTBLK) != 0) 589 ld_fast_sigblock = true; 590 591 trust = !issetugid(); 592 direct_exec = false; 593 594 md_abi_variant_hook(aux_info); 595 rtld_init_env_vars(env); 596 597 fd = -1; 598 if (aux_info[AT_EXECFD] != NULL) { 599 fd = aux_info[AT_EXECFD]->a_un.a_val; 600 } else { 601 assert(aux_info[AT_PHDR] != NULL); 602 phdr = (const Elf_Phdr *)aux_info[AT_PHDR]->a_un.a_ptr; 603 if (phdr == obj_rtld.phdr) { 604 if (!trust) { 605 _rtld_error("Tainted process refusing to run binary %s", 606 argv0); 607 rtld_die(); 608 } 609 direct_exec = true; 610 611 dbg("opening main program in direct exec mode"); 612 if (argc >= 2) { 613 rtld_argc = parse_args(argv, argc, &search_in_path, &fd, 614 &argv0, &dir_ignore); 615 explicit_fd = (fd != -1); 616 binpath = NULL; 617 if (!explicit_fd) 618 fd = open_binary_fd(argv0, search_in_path, &binpath); 619 if (fstat(fd, &st) == -1) { 620 _rtld_error("Failed to fstat FD %d (%s): %s", fd, 621 explicit_fd ? "user-provided descriptor" : argv0, 622 rtld_strerror(errno)); 623 rtld_die(); 624 } 625 626 /* 627 * Rough emulation of the permission checks done by 628 * execve(2), only Unix DACs are checked, ACLs are 629 * ignored. Preserve the semantic of disabling owner 630 * to execute if owner x bit is cleared, even if 631 * others x bit is enabled. 632 * mmap(2) does not allow to mmap with PROT_EXEC if 633 * binary' file comes from noexec mount. We cannot 634 * set a text reference on the binary. 635 */ 636 dir_enable = false; 637 if (st.st_uid == geteuid()) { 638 if ((st.st_mode & S_IXUSR) != 0) 639 dir_enable = true; 640 } else if (st.st_gid == getegid()) { 641 if ((st.st_mode & S_IXGRP) != 0) 642 dir_enable = true; 643 } else if ((st.st_mode & S_IXOTH) != 0) { 644 dir_enable = true; 645 } 646 if (!dir_enable && !dir_ignore) { 647 _rtld_error("No execute permission for binary %s", 648 argv0); 649 rtld_die(); 650 } 651 652 /* 653 * For direct exec mode, argv[0] is the interpreter 654 * name, we must remove it and shift arguments left 655 * before invoking binary main. Since stack layout 656 * places environment pointers and aux vectors right 657 * after the terminating NULL, we must shift 658 * environment and aux as well. 659 */ 660 main_argc = argc - rtld_argc; 661 for (i = 0; i <= main_argc; i++) 662 argv[i] = argv[i + rtld_argc]; 663 *argcp -= rtld_argc; 664 environ = env = envp = argv + main_argc + 1; 665 dbg("move env from %p to %p", envp + rtld_argc, envp); 666 do { 667 *envp = *(envp + rtld_argc); 668 } while (*envp++ != NULL); 669 aux = auxp = (Elf_Auxinfo *)envp; 670 auxpf = (Elf_Auxinfo *)(envp + rtld_argc); 671 dbg("move aux from %p to %p", auxpf, aux); 672 /* XXXKIB insert place for AT_EXECPATH if not present */ 673 for (;; auxp++, auxpf++) { 674 *auxp = *auxpf; 675 if (auxp->a_type == AT_NULL) 676 break; 677 } 678 /* Since the auxiliary vector has moved, redigest it. */ 679 for (i = 0; i < AT_COUNT; i++) 680 aux_info[i] = NULL; 681 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) { 682 if (auxp->a_type < AT_COUNT) 683 aux_info[auxp->a_type] = auxp; 684 } 685 686 /* Point AT_EXECPATH auxv and aux_info to the binary path. */ 687 if (binpath == NULL) { 688 aux_info[AT_EXECPATH] = NULL; 689 } else { 690 if (aux_info[AT_EXECPATH] == NULL) { 691 aux_info[AT_EXECPATH] = xmalloc(sizeof(Elf_Auxinfo)); 692 aux_info[AT_EXECPATH]->a_type = AT_EXECPATH; 693 } 694 aux_info[AT_EXECPATH]->a_un.a_ptr = __DECONST(void *, 695 binpath); 696 } 697 } else { 698 _rtld_error("No binary"); 699 rtld_die(); 700 } 701 } 702 } 703 704 ld_bind_now = ld_get_env_var(LD_BIND_NOW); 705 706 /* 707 * If the process is tainted, then we un-set the dangerous environment 708 * variables. The process will be marked as tainted until setuid(2) 709 * is called. If any child process calls setuid(2) we do not want any 710 * future processes to honor the potentially un-safe variables. 711 */ 712 if (!trust) { 713 for (i = 0; i < (int)nitems(ld_env_vars); i++) { 714 lvd = &ld_env_vars[i]; 715 if (lvd->unsecure) 716 lvd->val = NULL; 717 } 718 } 719 720 ld_debug = ld_get_env_var(LD_DEBUG); 721 if (ld_bind_now == NULL) 722 ld_bind_not = ld_get_env_var(LD_BIND_NOT) != NULL; 723 ld_dynamic_weak = ld_get_env_var(LD_DYNAMIC_WEAK) == NULL; 724 libmap_disable = ld_get_env_var(LD_LIBMAP_DISABLE) != NULL; 725 libmap_override = ld_get_env_var(LD_LIBMAP); 726 ld_library_path = ld_get_env_var(LD_LIBRARY_PATH); 727 ld_library_dirs = ld_get_env_var(LD_LIBRARY_PATH_FDS); 728 ld_preload = ld_get_env_var(LD_PRELOAD); 729 ld_preload_fds = ld_get_env_var(LD_PRELOAD_FDS); 730 ld_elf_hints_path = ld_get_env_var(LD_ELF_HINTS_PATH); 731 ld_loadfltr = ld_get_env_var(LD_LOADFLTR) != NULL; 732 library_path_rpath = ld_get_env_var(LD_LIBRARY_PATH_RPATH); 733 if (library_path_rpath != NULL) { 734 if (library_path_rpath[0] == 'y' || 735 library_path_rpath[0] == 'Y' || 736 library_path_rpath[0] == '1') 737 ld_library_path_rpath = true; 738 else 739 ld_library_path_rpath = false; 740 } 741 dangerous_ld_env = libmap_disable || libmap_override != NULL || 742 ld_library_path != NULL || ld_preload != NULL || 743 ld_elf_hints_path != NULL || ld_loadfltr || !ld_dynamic_weak; 744 ld_tracing = ld_get_env_var(LD_TRACE_LOADED_OBJECTS); 745 ld_utrace = ld_get_env_var(LD_UTRACE); 746 747 set_ld_elf_hints_path(); 748 if (ld_debug != NULL && *ld_debug != '\0') 749 debug = 1; 750 dbg("%s is initialized, base address = %p", __progname, 751 (caddr_t) aux_info[AT_BASE]->a_un.a_ptr); 752 dbg("RTLD dynamic = %p", obj_rtld.dynamic); 753 dbg("RTLD pltgot = %p", obj_rtld.pltgot); 754 755 dbg("initializing thread locks"); 756 lockdflt_init(); 757 758 /* 759 * Load the main program, or process its program header if it is 760 * already loaded. 761 */ 762 if (fd != -1) { /* Load the main program. */ 763 dbg("loading main program"); 764 obj_main = map_object(fd, argv0, NULL); 765 close(fd); 766 if (obj_main == NULL) 767 rtld_die(); 768 max_stack_flags = obj_main->stack_flags; 769 } else { /* Main program already loaded. */ 770 dbg("processing main program's program header"); 771 assert(aux_info[AT_PHDR] != NULL); 772 phdr = (const Elf_Phdr *) aux_info[AT_PHDR]->a_un.a_ptr; 773 assert(aux_info[AT_PHNUM] != NULL); 774 phnum = aux_info[AT_PHNUM]->a_un.a_val; 775 assert(aux_info[AT_PHENT] != NULL); 776 assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr)); 777 assert(aux_info[AT_ENTRY] != NULL); 778 imgentry = (caddr_t) aux_info[AT_ENTRY]->a_un.a_ptr; 779 if ((obj_main = digest_phdr(phdr, phnum, imgentry, argv0)) == NULL) 780 rtld_die(); 781 } 782 783 if (aux_info[AT_EXECPATH] != NULL && fd == -1) { 784 kexecpath = aux_info[AT_EXECPATH]->a_un.a_ptr; 785 dbg("AT_EXECPATH %p %s", kexecpath, kexecpath); 786 if (kexecpath[0] == '/') 787 obj_main->path = kexecpath; 788 else if (getcwd(buf, sizeof(buf)) == NULL || 789 strlcat(buf, "/", sizeof(buf)) >= sizeof(buf) || 790 strlcat(buf, kexecpath, sizeof(buf)) >= sizeof(buf)) 791 obj_main->path = xstrdup(argv0); 792 else 793 obj_main->path = xstrdup(buf); 794 } else { 795 dbg("No AT_EXECPATH or direct exec"); 796 obj_main->path = xstrdup(argv0); 797 } 798 dbg("obj_main path %s", obj_main->path); 799 obj_main->mainprog = true; 800 801 if (aux_info[AT_STACKPROT] != NULL && 802 aux_info[AT_STACKPROT]->a_un.a_val != 0) 803 stack_prot = aux_info[AT_STACKPROT]->a_un.a_val; 804 805 #ifndef COMPAT_libcompat 806 /* 807 * Get the actual dynamic linker pathname from the executable if 808 * possible. (It should always be possible.) That ensures that 809 * gdb will find the right dynamic linker even if a non-standard 810 * one is being used. 811 */ 812 if (obj_main->interp != NULL && 813 strcmp(obj_main->interp, obj_rtld.path) != 0) { 814 free(obj_rtld.path); 815 obj_rtld.path = xstrdup(obj_main->interp); 816 __progname = obj_rtld.path; 817 } 818 #endif 819 820 if (!digest_dynamic(obj_main, 0)) 821 rtld_die(); 822 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", 823 obj_main->path, obj_main->valid_hash_sysv, obj_main->valid_hash_gnu, 824 obj_main->dynsymcount); 825 826 linkmap_add(obj_main); 827 linkmap_add(&obj_rtld); 828 829 /* Link the main program into the list of objects. */ 830 TAILQ_INSERT_HEAD(&obj_list, obj_main, next); 831 obj_count++; 832 obj_loads++; 833 834 /* Initialize a fake symbol for resolving undefined weak references. */ 835 sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE); 836 sym_zero.st_shndx = SHN_UNDEF; 837 sym_zero.st_value = -(uintptr_t)obj_main->relocbase; 838 839 if (!libmap_disable) 840 libmap_disable = (bool)lm_init(libmap_override); 841 842 if (aux_info[AT_KPRELOAD] != NULL && 843 aux_info[AT_KPRELOAD]->a_un.a_ptr != NULL) { 844 dbg("loading kernel vdso"); 845 if (load_kpreload(aux_info[AT_KPRELOAD]->a_un.a_ptr) == -1) 846 rtld_die(); 847 } 848 849 dbg("loading LD_PRELOAD_FDS libraries"); 850 if (load_preload_objects(ld_preload_fds, true) == -1) 851 rtld_die(); 852 853 dbg("loading LD_PRELOAD libraries"); 854 if (load_preload_objects(ld_preload, false) == -1) 855 rtld_die(); 856 preload_tail = globallist_curr(TAILQ_LAST(&obj_list, obj_entry_q)); 857 858 dbg("loading needed objects"); 859 if (load_needed_objects(obj_main, ld_tracing != NULL ? RTLD_LO_TRACE : 860 0) == -1) 861 rtld_die(); 862 863 /* Make a list of all objects loaded at startup. */ 864 last_interposer = obj_main; 865 TAILQ_FOREACH(obj, &obj_list, next) { 866 if (obj->marker) 867 continue; 868 if (obj->z_interpose && obj != obj_main) { 869 objlist_put_after(&list_main, last_interposer, obj); 870 last_interposer = obj; 871 } else { 872 objlist_push_tail(&list_main, obj); 873 } 874 obj->refcount++; 875 } 876 877 dbg("checking for required versions"); 878 if (rtld_verify_versions(&list_main) == -1 && !ld_tracing) 879 rtld_die(); 880 881 if (ld_get_env_var(LD_SHOW_AUXV) != NULL) 882 dump_auxv(aux_info); 883 884 if (ld_tracing) { /* We're done */ 885 trace_loaded_objects(obj_main, true); 886 exit(0); 887 } 888 889 if (ld_get_env_var(LD_DUMP_REL_PRE) != NULL) { 890 dump_relocations(obj_main); 891 exit (0); 892 } 893 894 /* 895 * Processing tls relocations requires having the tls offsets 896 * initialized. Prepare offsets before starting initial 897 * relocation processing. 898 */ 899 dbg("initializing initial thread local storage offsets"); 900 STAILQ_FOREACH(entry, &list_main, link) { 901 /* 902 * Allocate all the initial objects out of the static TLS 903 * block even if they didn't ask for it. 904 */ 905 allocate_tls_offset(entry->obj); 906 } 907 908 if (relocate_objects(obj_main, 909 ld_bind_now != NULL && *ld_bind_now != '\0', 910 &obj_rtld, SYMLOOK_EARLY, NULL) == -1) 911 rtld_die(); 912 913 dbg("doing copy relocations"); 914 if (do_copy_relocations(obj_main) == -1) 915 rtld_die(); 916 917 if (ld_get_env_var(LD_DUMP_REL_POST) != NULL) { 918 dump_relocations(obj_main); 919 exit (0); 920 } 921 922 ifunc_init(aux); 923 924 /* 925 * Setup TLS for main thread. This must be done after the 926 * relocations are processed, since tls initialization section 927 * might be the subject for relocations. 928 */ 929 dbg("initializing initial thread local storage"); 930 allocate_initial_tls(globallist_curr(TAILQ_FIRST(&obj_list))); 931 932 dbg("initializing key program variables"); 933 set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : ""); 934 set_program_var("environ", env); 935 set_program_var("__elf_aux_vector", aux); 936 937 /* Make a list of init functions to call. */ 938 objlist_init(&initlist); 939 initlist_add_objects(globallist_curr(TAILQ_FIRST(&obj_list)), 940 preload_tail, &initlist); 941 942 r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */ 943 944 map_stacks_exec(NULL); 945 946 if (!obj_main->crt_no_init) { 947 /* 948 * Make sure we don't call the main program's init and fini 949 * functions for binaries linked with old crt1 which calls 950 * _init itself. 951 */ 952 obj_main->init = obj_main->fini = (Elf_Addr)NULL; 953 obj_main->preinit_array = obj_main->init_array = 954 obj_main->fini_array = (Elf_Addr)NULL; 955 } 956 957 if (direct_exec) { 958 /* Set osrel for direct-execed binary */ 959 mib[0] = CTL_KERN; 960 mib[1] = KERN_PROC; 961 mib[2] = KERN_PROC_OSREL; 962 mib[3] = getpid(); 963 osrel = obj_main->osrel; 964 sz = sizeof(old_osrel); 965 dbg("setting osrel to %d", osrel); 966 (void)sysctl(mib, 4, &old_osrel, &sz, &osrel, sizeof(osrel)); 967 } 968 969 wlock_acquire(rtld_bind_lock, &lockstate); 970 971 dbg("resolving ifuncs"); 972 if (initlist_objects_ifunc(&initlist, ld_bind_now != NULL && 973 *ld_bind_now != '\0', SYMLOOK_EARLY, &lockstate) == -1) 974 rtld_die(); 975 976 rtld_exit_ptr = rtld_exit; 977 if (obj_main->crt_no_init) 978 preinit_main(); 979 objlist_call_init(&initlist, &lockstate); 980 _r_debug_postinit(&obj_main->linkmap); 981 objlist_clear(&initlist); 982 dbg("loading filtees"); 983 TAILQ_FOREACH(obj, &obj_list, next) { 984 if (obj->marker) 985 continue; 986 if (ld_loadfltr || obj->z_loadfltr) 987 load_filtees(obj, 0, &lockstate); 988 } 989 990 dbg("enforcing main obj relro"); 991 if (obj_enforce_relro(obj_main) == -1) 992 rtld_die(); 993 994 lock_release(rtld_bind_lock, &lockstate); 995 996 dbg("transferring control to program entry point = %p", obj_main->entry); 997 998 /* Return the exit procedure and the program entry point. */ 999 *exit_proc = rtld_exit_ptr; 1000 *objp = obj_main; 1001 return ((func_ptr_type)obj_main->entry); 1002 } 1003 1004 void * 1005 rtld_resolve_ifunc(const Obj_Entry *obj, const Elf_Sym *def) 1006 { 1007 void *ptr; 1008 Elf_Addr target; 1009 1010 ptr = (void *)make_function_pointer(def, obj); 1011 target = call_ifunc_resolver(ptr); 1012 return ((void *)target); 1013 } 1014 1015 Elf_Addr 1016 _rtld_bind(Obj_Entry *obj, Elf_Size reloff) 1017 { 1018 const Elf_Rel *rel; 1019 const Elf_Sym *def; 1020 const Obj_Entry *defobj; 1021 Elf_Addr *where; 1022 Elf_Addr target; 1023 RtldLockState lockstate; 1024 1025 rlock_acquire(rtld_bind_lock, &lockstate); 1026 if (sigsetjmp(lockstate.env, 0) != 0) 1027 lock_upgrade(rtld_bind_lock, &lockstate); 1028 if (obj->pltrel) 1029 rel = (const Elf_Rel *)((const char *)obj->pltrel + reloff); 1030 else 1031 rel = (const Elf_Rel *)((const char *)obj->pltrela + reloff); 1032 1033 where = (Elf_Addr *)(obj->relocbase + rel->r_offset); 1034 def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, SYMLOOK_IN_PLT, 1035 NULL, &lockstate); 1036 if (def == NULL) 1037 rtld_die(); 1038 if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 1039 target = (Elf_Addr)rtld_resolve_ifunc(defobj, def); 1040 else 1041 target = (Elf_Addr)(defobj->relocbase + def->st_value); 1042 1043 dbg("\"%s\" in \"%s\" ==> %p in \"%s\"", 1044 defobj->strtab + def->st_name, 1045 obj->path == NULL ? NULL : basename(obj->path), 1046 (void *)target, 1047 defobj->path == NULL ? NULL : basename(defobj->path)); 1048 1049 /* 1050 * Write the new contents for the jmpslot. Note that depending on 1051 * architecture, the value which we need to return back to the 1052 * lazy binding trampoline may or may not be the target 1053 * address. The value returned from reloc_jmpslot() is the value 1054 * that the trampoline needs. 1055 */ 1056 target = reloc_jmpslot(where, target, defobj, obj, rel); 1057 lock_release(rtld_bind_lock, &lockstate); 1058 return (target); 1059 } 1060 1061 /* 1062 * Error reporting function. Use it like printf. If formats the message 1063 * into a buffer, and sets things up so that the next call to dlerror() 1064 * will return the message. 1065 */ 1066 void 1067 _rtld_error(const char *fmt, ...) 1068 { 1069 va_list ap; 1070 1071 va_start(ap, fmt); 1072 rtld_vsnprintf(lockinfo.dlerror_loc(), lockinfo.dlerror_loc_sz, 1073 fmt, ap); 1074 va_end(ap); 1075 *lockinfo.dlerror_seen() = 0; 1076 LD_UTRACE(UTRACE_RTLD_ERROR, NULL, NULL, 0, 0, lockinfo.dlerror_loc()); 1077 } 1078 1079 /* 1080 * Return a dynamically-allocated copy of the current error message, if any. 1081 */ 1082 static struct dlerror_save * 1083 errmsg_save(void) 1084 { 1085 struct dlerror_save *res; 1086 1087 res = xmalloc(sizeof(*res)); 1088 res->seen = *lockinfo.dlerror_seen(); 1089 if (res->seen == 0) 1090 res->msg = xstrdup(lockinfo.dlerror_loc()); 1091 return (res); 1092 } 1093 1094 /* 1095 * Restore the current error message from a copy which was previously saved 1096 * by errmsg_save(). The copy is freed. 1097 */ 1098 static void 1099 errmsg_restore(struct dlerror_save *saved_msg) 1100 { 1101 if (saved_msg == NULL || saved_msg->seen == 1) { 1102 *lockinfo.dlerror_seen() = 1; 1103 } else { 1104 *lockinfo.dlerror_seen() = 0; 1105 strlcpy(lockinfo.dlerror_loc(), saved_msg->msg, 1106 lockinfo.dlerror_loc_sz); 1107 free(saved_msg->msg); 1108 } 1109 free(saved_msg); 1110 } 1111 1112 static const char * 1113 basename(const char *name) 1114 { 1115 const char *p; 1116 1117 p = strrchr(name, '/'); 1118 return (p != NULL ? p + 1 : name); 1119 } 1120 1121 static struct utsname uts; 1122 1123 static char * 1124 origin_subst_one(Obj_Entry *obj, char *real, const char *kw, 1125 const char *subst, bool may_free) 1126 { 1127 char *p, *p1, *res, *resp; 1128 int subst_len, kw_len, subst_count, old_len, new_len; 1129 1130 kw_len = strlen(kw); 1131 1132 /* 1133 * First, count the number of the keyword occurrences, to 1134 * preallocate the final string. 1135 */ 1136 for (p = real, subst_count = 0;; p = p1 + kw_len, subst_count++) { 1137 p1 = strstr(p, kw); 1138 if (p1 == NULL) 1139 break; 1140 } 1141 1142 /* 1143 * If the keyword is not found, just return. 1144 * 1145 * Return non-substituted string if resolution failed. We 1146 * cannot do anything more reasonable, the failure mode of the 1147 * caller is unresolved library anyway. 1148 */ 1149 if (subst_count == 0 || (obj != NULL && !obj_resolve_origin(obj))) 1150 return (may_free ? real : xstrdup(real)); 1151 if (obj != NULL) 1152 subst = obj->origin_path; 1153 1154 /* 1155 * There is indeed something to substitute. Calculate the 1156 * length of the resulting string, and allocate it. 1157 */ 1158 subst_len = strlen(subst); 1159 old_len = strlen(real); 1160 new_len = old_len + (subst_len - kw_len) * subst_count; 1161 res = xmalloc(new_len + 1); 1162 1163 /* 1164 * Now, execute the substitution loop. 1165 */ 1166 for (p = real, resp = res, *resp = '\0';;) { 1167 p1 = strstr(p, kw); 1168 if (p1 != NULL) { 1169 /* Copy the prefix before keyword. */ 1170 memcpy(resp, p, p1 - p); 1171 resp += p1 - p; 1172 /* Keyword replacement. */ 1173 memcpy(resp, subst, subst_len); 1174 resp += subst_len; 1175 *resp = '\0'; 1176 p = p1 + kw_len; 1177 } else 1178 break; 1179 } 1180 1181 /* Copy to the end of string and finish. */ 1182 strcat(resp, p); 1183 if (may_free) 1184 free(real); 1185 return (res); 1186 } 1187 1188 static const struct { 1189 const char *kw; 1190 bool pass_obj; 1191 const char *subst; 1192 } tokens[] = { 1193 { .kw = "$ORIGIN", .pass_obj = true, .subst = NULL }, 1194 { .kw = "${ORIGIN}", .pass_obj = true, .subst = NULL }, 1195 { .kw = "$OSNAME", .pass_obj = false, .subst = uts.sysname }, 1196 { .kw = "${OSNAME}", .pass_obj = false, .subst = uts.sysname }, 1197 { .kw = "$OSREL", .pass_obj = false, .subst = uts.release }, 1198 { .kw = "${OSREL}", .pass_obj = false, .subst = uts.release }, 1199 { .kw = "$PLATFORM", .pass_obj = false, .subst = uts.machine }, 1200 { .kw = "${PLATFORM}", .pass_obj = false, .subst = uts.machine }, 1201 { .kw = "$LIB", .pass_obj = false, .subst = TOKEN_LIB }, 1202 { .kw = "${LIB}", .pass_obj = false, .subst = TOKEN_LIB }, 1203 }; 1204 1205 static char * 1206 origin_subst(Obj_Entry *obj, const char *real) 1207 { 1208 char *res; 1209 int i; 1210 1211 if (obj == NULL || !trust) 1212 return (xstrdup(real)); 1213 if (uts.sysname[0] == '\0') { 1214 if (uname(&uts) != 0) { 1215 _rtld_error("utsname failed: %d", errno); 1216 return (NULL); 1217 } 1218 } 1219 1220 /* __DECONST is safe here since without may_free real is unchanged */ 1221 res = __DECONST(char *, real); 1222 for (i = 0; i < (int)nitems(tokens); i++) { 1223 res = origin_subst_one(tokens[i].pass_obj ? obj : NULL, 1224 res, tokens[i].kw, tokens[i].subst, i != 0); 1225 } 1226 return (res); 1227 } 1228 1229 void 1230 rtld_die(void) 1231 { 1232 const char *msg = dlerror(); 1233 1234 if (msg == NULL) 1235 msg = "Fatal error"; 1236 rtld_fdputstr(STDERR_FILENO, _BASENAME_RTLD ": "); 1237 rtld_fdputstr(STDERR_FILENO, msg); 1238 rtld_fdputchar(STDERR_FILENO, '\n'); 1239 _exit(1); 1240 } 1241 1242 /* 1243 * Process a shared object's DYNAMIC section, and save the important 1244 * information in its Obj_Entry structure. 1245 */ 1246 static void 1247 digest_dynamic1(Obj_Entry *obj, int early, const Elf_Dyn **dyn_rpath, 1248 const Elf_Dyn **dyn_soname, const Elf_Dyn **dyn_runpath) 1249 { 1250 const Elf_Dyn *dynp; 1251 Needed_Entry **needed_tail = &obj->needed; 1252 Needed_Entry **needed_filtees_tail = &obj->needed_filtees; 1253 Needed_Entry **needed_aux_filtees_tail = &obj->needed_aux_filtees; 1254 const Elf_Hashelt *hashtab; 1255 const Elf32_Word *hashval; 1256 Elf32_Word bkt, nmaskwords; 1257 int bloom_size32; 1258 int plttype = DT_REL; 1259 1260 *dyn_rpath = NULL; 1261 *dyn_soname = NULL; 1262 *dyn_runpath = NULL; 1263 1264 obj->bind_now = false; 1265 dynp = obj->dynamic; 1266 if (dynp == NULL) 1267 return; 1268 for (; dynp->d_tag != DT_NULL; dynp++) { 1269 switch (dynp->d_tag) { 1270 1271 case DT_REL: 1272 obj->rel = (const Elf_Rel *)(obj->relocbase + dynp->d_un.d_ptr); 1273 break; 1274 1275 case DT_RELSZ: 1276 obj->relsize = dynp->d_un.d_val; 1277 break; 1278 1279 case DT_RELENT: 1280 assert(dynp->d_un.d_val == sizeof(Elf_Rel)); 1281 break; 1282 1283 case DT_JMPREL: 1284 obj->pltrel = (const Elf_Rel *) 1285 (obj->relocbase + dynp->d_un.d_ptr); 1286 break; 1287 1288 case DT_PLTRELSZ: 1289 obj->pltrelsize = dynp->d_un.d_val; 1290 break; 1291 1292 case DT_RELA: 1293 obj->rela = (const Elf_Rela *)(obj->relocbase + dynp->d_un.d_ptr); 1294 break; 1295 1296 case DT_RELASZ: 1297 obj->relasize = dynp->d_un.d_val; 1298 break; 1299 1300 case DT_RELAENT: 1301 assert(dynp->d_un.d_val == sizeof(Elf_Rela)); 1302 break; 1303 1304 case DT_RELR: 1305 obj->relr = (const Elf_Relr *)(obj->relocbase + dynp->d_un.d_ptr); 1306 break; 1307 1308 case DT_RELRSZ: 1309 obj->relrsize = dynp->d_un.d_val; 1310 break; 1311 1312 case DT_RELRENT: 1313 assert(dynp->d_un.d_val == sizeof(Elf_Relr)); 1314 break; 1315 1316 case DT_PLTREL: 1317 plttype = dynp->d_un.d_val; 1318 assert(dynp->d_un.d_val == DT_REL || plttype == DT_RELA); 1319 break; 1320 1321 case DT_SYMTAB: 1322 obj->symtab = (const Elf_Sym *) 1323 (obj->relocbase + dynp->d_un.d_ptr); 1324 break; 1325 1326 case DT_SYMENT: 1327 assert(dynp->d_un.d_val == sizeof(Elf_Sym)); 1328 break; 1329 1330 case DT_STRTAB: 1331 obj->strtab = (const char *)(obj->relocbase + dynp->d_un.d_ptr); 1332 break; 1333 1334 case DT_STRSZ: 1335 obj->strsize = dynp->d_un.d_val; 1336 break; 1337 1338 case DT_VERNEED: 1339 obj->verneed = (const Elf_Verneed *)(obj->relocbase + 1340 dynp->d_un.d_val); 1341 break; 1342 1343 case DT_VERNEEDNUM: 1344 obj->verneednum = dynp->d_un.d_val; 1345 break; 1346 1347 case DT_VERDEF: 1348 obj->verdef = (const Elf_Verdef *)(obj->relocbase + 1349 dynp->d_un.d_val); 1350 break; 1351 1352 case DT_VERDEFNUM: 1353 obj->verdefnum = dynp->d_un.d_val; 1354 break; 1355 1356 case DT_VERSYM: 1357 obj->versyms = (const Elf_Versym *)(obj->relocbase + 1358 dynp->d_un.d_val); 1359 break; 1360 1361 case DT_HASH: 1362 { 1363 hashtab = (const Elf_Hashelt *)(obj->relocbase + 1364 dynp->d_un.d_ptr); 1365 obj->nbuckets = hashtab[0]; 1366 obj->nchains = hashtab[1]; 1367 obj->buckets = hashtab + 2; 1368 obj->chains = obj->buckets + obj->nbuckets; 1369 obj->valid_hash_sysv = obj->nbuckets > 0 && obj->nchains > 0 && 1370 obj->buckets != NULL; 1371 } 1372 break; 1373 1374 case DT_GNU_HASH: 1375 { 1376 hashtab = (const Elf_Hashelt *)(obj->relocbase + 1377 dynp->d_un.d_ptr); 1378 obj->nbuckets_gnu = hashtab[0]; 1379 obj->symndx_gnu = hashtab[1]; 1380 nmaskwords = hashtab[2]; 1381 bloom_size32 = (__ELF_WORD_SIZE / 32) * nmaskwords; 1382 obj->maskwords_bm_gnu = nmaskwords - 1; 1383 obj->shift2_gnu = hashtab[3]; 1384 obj->bloom_gnu = (const Elf_Addr *)(hashtab + 4); 1385 obj->buckets_gnu = hashtab + 4 + bloom_size32; 1386 obj->chain_zero_gnu = obj->buckets_gnu + obj->nbuckets_gnu - 1387 obj->symndx_gnu; 1388 /* Number of bitmask words is required to be power of 2 */ 1389 obj->valid_hash_gnu = powerof2(nmaskwords) && 1390 obj->nbuckets_gnu > 0 && obj->buckets_gnu != NULL; 1391 } 1392 break; 1393 1394 case DT_NEEDED: 1395 if (!obj->rtld) { 1396 Needed_Entry *nep = NEW(Needed_Entry); 1397 nep->name = dynp->d_un.d_val; 1398 nep->obj = NULL; 1399 nep->next = NULL; 1400 1401 *needed_tail = nep; 1402 needed_tail = &nep->next; 1403 } 1404 break; 1405 1406 case DT_FILTER: 1407 if (!obj->rtld) { 1408 Needed_Entry *nep = NEW(Needed_Entry); 1409 nep->name = dynp->d_un.d_val; 1410 nep->obj = NULL; 1411 nep->next = NULL; 1412 1413 *needed_filtees_tail = nep; 1414 needed_filtees_tail = &nep->next; 1415 1416 if (obj->linkmap.l_refname == NULL) 1417 obj->linkmap.l_refname = (char *)dynp->d_un.d_val; 1418 } 1419 break; 1420 1421 case DT_AUXILIARY: 1422 if (!obj->rtld) { 1423 Needed_Entry *nep = NEW(Needed_Entry); 1424 nep->name = dynp->d_un.d_val; 1425 nep->obj = NULL; 1426 nep->next = NULL; 1427 1428 *needed_aux_filtees_tail = nep; 1429 needed_aux_filtees_tail = &nep->next; 1430 } 1431 break; 1432 1433 case DT_PLTGOT: 1434 obj->pltgot = (Elf_Addr *)(obj->relocbase + dynp->d_un.d_ptr); 1435 break; 1436 1437 case DT_TEXTREL: 1438 obj->textrel = true; 1439 break; 1440 1441 case DT_SYMBOLIC: 1442 obj->symbolic = true; 1443 break; 1444 1445 case DT_RPATH: 1446 /* 1447 * We have to wait until later to process this, because we 1448 * might not have gotten the address of the string table yet. 1449 */ 1450 *dyn_rpath = dynp; 1451 break; 1452 1453 case DT_SONAME: 1454 *dyn_soname = dynp; 1455 break; 1456 1457 case DT_RUNPATH: 1458 *dyn_runpath = dynp; 1459 break; 1460 1461 case DT_INIT: 1462 obj->init = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1463 break; 1464 1465 case DT_PREINIT_ARRAY: 1466 obj->preinit_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1467 break; 1468 1469 case DT_PREINIT_ARRAYSZ: 1470 obj->preinit_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1471 break; 1472 1473 case DT_INIT_ARRAY: 1474 obj->init_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1475 break; 1476 1477 case DT_INIT_ARRAYSZ: 1478 obj->init_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1479 break; 1480 1481 case DT_FINI: 1482 obj->fini = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1483 break; 1484 1485 case DT_FINI_ARRAY: 1486 obj->fini_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1487 break; 1488 1489 case DT_FINI_ARRAYSZ: 1490 obj->fini_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1491 break; 1492 1493 case DT_DEBUG: 1494 if (!early) 1495 dbg("Filling in DT_DEBUG entry"); 1496 (__DECONST(Elf_Dyn *, dynp))->d_un.d_ptr = (Elf_Addr)&r_debug; 1497 break; 1498 1499 case DT_FLAGS: 1500 if (dynp->d_un.d_val & DF_ORIGIN) 1501 obj->z_origin = true; 1502 if (dynp->d_un.d_val & DF_SYMBOLIC) 1503 obj->symbolic = true; 1504 if (dynp->d_un.d_val & DF_TEXTREL) 1505 obj->textrel = true; 1506 if (dynp->d_un.d_val & DF_BIND_NOW) 1507 obj->bind_now = true; 1508 if (dynp->d_un.d_val & DF_STATIC_TLS) 1509 obj->static_tls = true; 1510 break; 1511 1512 #ifdef __powerpc__ 1513 #ifdef __powerpc64__ 1514 case DT_PPC64_GLINK: 1515 obj->glink = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1516 break; 1517 #else 1518 case DT_PPC_GOT: 1519 obj->gotptr = (Elf_Addr *)(obj->relocbase + dynp->d_un.d_ptr); 1520 break; 1521 #endif 1522 #endif 1523 1524 case DT_FLAGS_1: 1525 if (dynp->d_un.d_val & DF_1_NOOPEN) 1526 obj->z_noopen = true; 1527 if (dynp->d_un.d_val & DF_1_ORIGIN) 1528 obj->z_origin = true; 1529 if (dynp->d_un.d_val & DF_1_GLOBAL) 1530 obj->z_global = true; 1531 if (dynp->d_un.d_val & DF_1_BIND_NOW) 1532 obj->bind_now = true; 1533 if (dynp->d_un.d_val & DF_1_NODELETE) 1534 obj->z_nodelete = true; 1535 if (dynp->d_un.d_val & DF_1_LOADFLTR) 1536 obj->z_loadfltr = true; 1537 if (dynp->d_un.d_val & DF_1_INTERPOSE) 1538 obj->z_interpose = true; 1539 if (dynp->d_un.d_val & DF_1_NODEFLIB) 1540 obj->z_nodeflib = true; 1541 if (dynp->d_un.d_val & DF_1_PIE) 1542 obj->z_pie = true; 1543 break; 1544 1545 default: 1546 if (!early) { 1547 dbg("Ignoring d_tag %ld = %#lx", (long)dynp->d_tag, 1548 (long)dynp->d_tag); 1549 } 1550 break; 1551 } 1552 } 1553 1554 obj->traced = false; 1555 1556 if (plttype == DT_RELA) { 1557 obj->pltrela = (const Elf_Rela *) obj->pltrel; 1558 obj->pltrel = NULL; 1559 obj->pltrelasize = obj->pltrelsize; 1560 obj->pltrelsize = 0; 1561 } 1562 1563 /* Determine size of dynsym table (equal to nchains of sysv hash) */ 1564 if (obj->valid_hash_sysv) 1565 obj->dynsymcount = obj->nchains; 1566 else if (obj->valid_hash_gnu) { 1567 obj->dynsymcount = 0; 1568 for (bkt = 0; bkt < obj->nbuckets_gnu; bkt++) { 1569 if (obj->buckets_gnu[bkt] == 0) 1570 continue; 1571 hashval = &obj->chain_zero_gnu[obj->buckets_gnu[bkt]]; 1572 do 1573 obj->dynsymcount++; 1574 while ((*hashval++ & 1u) == 0); 1575 } 1576 obj->dynsymcount += obj->symndx_gnu; 1577 } 1578 1579 if (obj->linkmap.l_refname != NULL) 1580 obj->linkmap.l_refname = obj->strtab + (unsigned long)obj-> 1581 linkmap.l_refname; 1582 } 1583 1584 static bool 1585 obj_resolve_origin(Obj_Entry *obj) 1586 { 1587 1588 if (obj->origin_path != NULL) 1589 return (true); 1590 obj->origin_path = xmalloc(PATH_MAX); 1591 return (rtld_dirname_abs(obj->path, obj->origin_path) != -1); 1592 } 1593 1594 static bool 1595 digest_dynamic2(Obj_Entry *obj, const Elf_Dyn *dyn_rpath, 1596 const Elf_Dyn *dyn_soname, const Elf_Dyn *dyn_runpath) 1597 { 1598 1599 if (obj->z_origin && !obj_resolve_origin(obj)) 1600 return (false); 1601 1602 if (dyn_runpath != NULL) { 1603 obj->runpath = (const char *)obj->strtab + dyn_runpath->d_un.d_val; 1604 obj->runpath = origin_subst(obj, obj->runpath); 1605 } else if (dyn_rpath != NULL) { 1606 obj->rpath = (const char *)obj->strtab + dyn_rpath->d_un.d_val; 1607 obj->rpath = origin_subst(obj, obj->rpath); 1608 } 1609 if (dyn_soname != NULL) 1610 object_add_name(obj, obj->strtab + dyn_soname->d_un.d_val); 1611 return (true); 1612 } 1613 1614 static bool 1615 digest_dynamic(Obj_Entry *obj, int early) 1616 { 1617 const Elf_Dyn *dyn_rpath; 1618 const Elf_Dyn *dyn_soname; 1619 const Elf_Dyn *dyn_runpath; 1620 1621 digest_dynamic1(obj, early, &dyn_rpath, &dyn_soname, &dyn_runpath); 1622 return (digest_dynamic2(obj, dyn_rpath, dyn_soname, dyn_runpath)); 1623 } 1624 1625 /* 1626 * Process a shared object's program header. This is used only for the 1627 * main program, when the kernel has already loaded the main program 1628 * into memory before calling the dynamic linker. It creates and 1629 * returns an Obj_Entry structure. 1630 */ 1631 static Obj_Entry * 1632 digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path) 1633 { 1634 Obj_Entry *obj; 1635 const Elf_Phdr *phlimit = phdr + phnum; 1636 const Elf_Phdr *ph; 1637 Elf_Addr note_start, note_end; 1638 int nsegs = 0; 1639 1640 obj = obj_new(); 1641 for (ph = phdr; ph < phlimit; ph++) { 1642 if (ph->p_type != PT_PHDR) 1643 continue; 1644 1645 obj->phdr = phdr; 1646 obj->phsize = ph->p_memsz; 1647 obj->relocbase = __DECONST(char *, phdr) - ph->p_vaddr; 1648 break; 1649 } 1650 1651 obj->stack_flags = PF_X | PF_R | PF_W; 1652 1653 for (ph = phdr; ph < phlimit; ph++) { 1654 switch (ph->p_type) { 1655 1656 case PT_INTERP: 1657 obj->interp = (const char *)(ph->p_vaddr + obj->relocbase); 1658 break; 1659 1660 case PT_LOAD: 1661 if (nsegs == 0) { /* First load segment */ 1662 obj->vaddrbase = rtld_trunc_page(ph->p_vaddr); 1663 obj->mapbase = obj->vaddrbase + obj->relocbase; 1664 } else { /* Last load segment */ 1665 obj->mapsize = rtld_round_page(ph->p_vaddr + ph->p_memsz) - 1666 obj->vaddrbase; 1667 } 1668 nsegs++; 1669 break; 1670 1671 case PT_DYNAMIC: 1672 obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + obj->relocbase); 1673 break; 1674 1675 case PT_TLS: 1676 obj->tlsindex = 1; 1677 obj->tlssize = ph->p_memsz; 1678 obj->tlsalign = ph->p_align; 1679 obj->tlsinitsize = ph->p_filesz; 1680 obj->tlsinit = (void*)(ph->p_vaddr + obj->relocbase); 1681 obj->tlspoffset = ph->p_offset; 1682 break; 1683 1684 case PT_GNU_STACK: 1685 obj->stack_flags = ph->p_flags; 1686 break; 1687 1688 case PT_GNU_RELRO: 1689 obj->relro_page = obj->relocbase + rtld_trunc_page(ph->p_vaddr); 1690 obj->relro_size = rtld_trunc_page(ph->p_vaddr + ph->p_memsz) - 1691 rtld_trunc_page(ph->p_vaddr); 1692 break; 1693 1694 case PT_NOTE: 1695 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; 1696 note_end = note_start + ph->p_filesz; 1697 digest_notes(obj, note_start, note_end); 1698 break; 1699 } 1700 } 1701 if (nsegs < 1) { 1702 _rtld_error("%s: too few PT_LOAD segments", path); 1703 return (NULL); 1704 } 1705 1706 obj->entry = entry; 1707 return (obj); 1708 } 1709 1710 void 1711 digest_notes(Obj_Entry *obj, Elf_Addr note_start, Elf_Addr note_end) 1712 { 1713 const Elf_Note *note; 1714 const char *note_name; 1715 uintptr_t p; 1716 1717 for (note = (const Elf_Note *)note_start; (Elf_Addr)note < note_end; 1718 note = (const Elf_Note *)((const char *)(note + 1) + 1719 roundup2(note->n_namesz, sizeof(Elf32_Addr)) + 1720 roundup2(note->n_descsz, sizeof(Elf32_Addr)))) { 1721 if (note->n_namesz != sizeof(NOTE_FREEBSD_VENDOR) || 1722 note->n_descsz != sizeof(int32_t)) 1723 continue; 1724 if (note->n_type != NT_FREEBSD_ABI_TAG && 1725 note->n_type != NT_FREEBSD_FEATURE_CTL && 1726 note->n_type != NT_FREEBSD_NOINIT_TAG) 1727 continue; 1728 note_name = (const char *)(note + 1); 1729 if (strncmp(NOTE_FREEBSD_VENDOR, note_name, 1730 sizeof(NOTE_FREEBSD_VENDOR)) != 0) 1731 continue; 1732 switch (note->n_type) { 1733 case NT_FREEBSD_ABI_TAG: 1734 /* FreeBSD osrel note */ 1735 p = (uintptr_t)(note + 1); 1736 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1737 obj->osrel = *(const int32_t *)(p); 1738 dbg("note osrel %d", obj->osrel); 1739 break; 1740 case NT_FREEBSD_FEATURE_CTL: 1741 /* FreeBSD ABI feature control note */ 1742 p = (uintptr_t)(note + 1); 1743 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1744 obj->fctl0 = *(const uint32_t *)(p); 1745 dbg("note fctl0 %#x", obj->fctl0); 1746 break; 1747 case NT_FREEBSD_NOINIT_TAG: 1748 /* FreeBSD 'crt does not call init' note */ 1749 obj->crt_no_init = true; 1750 dbg("note crt_no_init"); 1751 break; 1752 } 1753 } 1754 } 1755 1756 static Obj_Entry * 1757 dlcheck(void *handle) 1758 { 1759 Obj_Entry *obj; 1760 1761 TAILQ_FOREACH(obj, &obj_list, next) { 1762 if (obj == (Obj_Entry *) handle) 1763 break; 1764 } 1765 1766 if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) { 1767 _rtld_error("Invalid shared object handle %p", handle); 1768 return (NULL); 1769 } 1770 return (obj); 1771 } 1772 1773 /* 1774 * If the given object is already in the donelist, return true. Otherwise 1775 * add the object to the list and return false. 1776 */ 1777 static bool 1778 donelist_check(DoneList *dlp, const Obj_Entry *obj) 1779 { 1780 unsigned int i; 1781 1782 for (i = 0; i < dlp->num_used; i++) 1783 if (dlp->objs[i] == obj) 1784 return (true); 1785 /* 1786 * Our donelist allocation should always be sufficient. But if 1787 * our threads locking isn't working properly, more shared objects 1788 * could have been loaded since we allocated the list. That should 1789 * never happen, but we'll handle it properly just in case it does. 1790 */ 1791 if (dlp->num_used < dlp->num_alloc) 1792 dlp->objs[dlp->num_used++] = obj; 1793 return (false); 1794 } 1795 1796 /* 1797 * SysV hash function for symbol table lookup. It is a slightly optimized 1798 * version of the hash specified by the System V ABI. 1799 */ 1800 Elf32_Word 1801 elf_hash(const char *name) 1802 { 1803 const unsigned char *p = (const unsigned char *)name; 1804 Elf32_Word h = 0; 1805 1806 while (*p != '\0') { 1807 h = (h << 4) + *p++; 1808 h ^= (h >> 24) & 0xf0; 1809 } 1810 return (h & 0x0fffffff); 1811 } 1812 1813 /* 1814 * The GNU hash function is the Daniel J. Bernstein hash clipped to 32 bits 1815 * unsigned in case it's implemented with a wider type. 1816 */ 1817 static uint32_t 1818 gnu_hash(const char *s) 1819 { 1820 uint32_t h; 1821 unsigned char c; 1822 1823 h = 5381; 1824 for (c = *s; c != '\0'; c = *++s) 1825 h = h * 33 + c; 1826 return (h & 0xffffffff); 1827 } 1828 1829 1830 /* 1831 * Find the library with the given name, and return its full pathname. 1832 * The returned string is dynamically allocated. Generates an error 1833 * message and returns NULL if the library cannot be found. 1834 * 1835 * If the second argument is non-NULL, then it refers to an already- 1836 * loaded shared object, whose library search path will be searched. 1837 * 1838 * If a library is successfully located via LD_LIBRARY_PATH_FDS, its 1839 * descriptor (which is close-on-exec) will be passed out via the third 1840 * argument. 1841 * 1842 * The search order is: 1843 * DT_RPATH in the referencing file _unless_ DT_RUNPATH is present (1) 1844 * DT_RPATH of the main object if DSO without defined DT_RUNPATH (1) 1845 * LD_LIBRARY_PATH 1846 * DT_RUNPATH in the referencing file 1847 * ldconfig hints (if -z nodefaultlib, filter out default library directories 1848 * from list) 1849 * /lib:/usr/lib _unless_ the referencing file is linked with -z nodefaultlib 1850 * 1851 * (1) Handled in digest_dynamic2 - rpath left NULL if runpath defined. 1852 */ 1853 static char * 1854 find_library(const char *xname, const Obj_Entry *refobj, int *fdp) 1855 { 1856 char *pathname, *refobj_path; 1857 const char *name; 1858 bool nodeflib, objgiven; 1859 1860 objgiven = refobj != NULL; 1861 1862 if (libmap_disable || !objgiven || 1863 (name = lm_find(refobj->path, xname)) == NULL) 1864 name = xname; 1865 1866 if (strchr(name, '/') != NULL) { /* Hard coded pathname */ 1867 if (name[0] != '/' && !trust) { 1868 _rtld_error("Absolute pathname required " 1869 "for shared object \"%s\"", name); 1870 return (NULL); 1871 } 1872 return (origin_subst(__DECONST(Obj_Entry *, refobj), 1873 __DECONST(char *, name))); 1874 } 1875 1876 dbg(" Searching for \"%s\"", name); 1877 refobj_path = objgiven ? refobj->path : NULL; 1878 1879 /* 1880 * If refobj->rpath != NULL, then refobj->runpath is NULL. Fall 1881 * back to pre-conforming behaviour if user requested so with 1882 * LD_LIBRARY_PATH_RPATH environment variable and ignore -z 1883 * nodeflib. 1884 */ 1885 if (objgiven && refobj->rpath != NULL && ld_library_path_rpath) { 1886 pathname = search_library_path(name, ld_library_path, 1887 refobj_path, fdp); 1888 if (pathname != NULL) 1889 return (pathname); 1890 if (refobj != NULL) { 1891 pathname = search_library_path(name, refobj->rpath, 1892 refobj_path, fdp); 1893 if (pathname != NULL) 1894 return (pathname); 1895 } 1896 pathname = search_library_pathfds(name, ld_library_dirs, fdp); 1897 if (pathname != NULL) 1898 return (pathname); 1899 pathname = search_library_path(name, gethints(false), 1900 refobj_path, fdp); 1901 if (pathname != NULL) 1902 return (pathname); 1903 pathname = search_library_path(name, ld_standard_library_path, 1904 refobj_path, fdp); 1905 if (pathname != NULL) 1906 return (pathname); 1907 } else { 1908 nodeflib = objgiven ? refobj->z_nodeflib : false; 1909 if (objgiven) { 1910 pathname = search_library_path(name, refobj->rpath, 1911 refobj->path, fdp); 1912 if (pathname != NULL) 1913 return (pathname); 1914 } 1915 if (objgiven && refobj->runpath == NULL && refobj != obj_main) { 1916 pathname = search_library_path(name, obj_main->rpath, 1917 refobj_path, fdp); 1918 if (pathname != NULL) 1919 return (pathname); 1920 } 1921 pathname = search_library_path(name, ld_library_path, 1922 refobj_path, fdp); 1923 if (pathname != NULL) 1924 return (pathname); 1925 if (objgiven) { 1926 pathname = search_library_path(name, refobj->runpath, 1927 refobj_path, fdp); 1928 if (pathname != NULL) 1929 return (pathname); 1930 } 1931 pathname = search_library_pathfds(name, ld_library_dirs, fdp); 1932 if (pathname != NULL) 1933 return (pathname); 1934 pathname = search_library_path(name, gethints(nodeflib), 1935 refobj_path, fdp); 1936 if (pathname != NULL) 1937 return (pathname); 1938 if (objgiven && !nodeflib) { 1939 pathname = search_library_path(name, 1940 ld_standard_library_path, refobj_path, fdp); 1941 if (pathname != NULL) 1942 return (pathname); 1943 } 1944 } 1945 1946 if (objgiven && refobj->path != NULL) { 1947 _rtld_error("Shared object \"%s\" not found, " 1948 "required by \"%s\"", name, basename(refobj->path)); 1949 } else { 1950 _rtld_error("Shared object \"%s\" not found", name); 1951 } 1952 return (NULL); 1953 } 1954 1955 /* 1956 * Given a symbol number in a referencing object, find the corresponding 1957 * definition of the symbol. Returns a pointer to the symbol, or NULL if 1958 * no definition was found. Returns a pointer to the Obj_Entry of the 1959 * defining object via the reference parameter DEFOBJ_OUT. 1960 */ 1961 const Elf_Sym * 1962 find_symdef(unsigned long symnum, const Obj_Entry *refobj, 1963 const Obj_Entry **defobj_out, int flags, SymCache *cache, 1964 RtldLockState *lockstate) 1965 { 1966 const Elf_Sym *ref; 1967 const Elf_Sym *def; 1968 const Obj_Entry *defobj; 1969 const Ver_Entry *ve; 1970 SymLook req; 1971 const char *name; 1972 int res; 1973 1974 /* 1975 * If we have already found this symbol, get the information from 1976 * the cache. 1977 */ 1978 if (symnum >= refobj->dynsymcount) 1979 return (NULL); /* Bad object */ 1980 if (cache != NULL && cache[symnum].sym != NULL) { 1981 *defobj_out = cache[symnum].obj; 1982 return (cache[symnum].sym); 1983 } 1984 1985 ref = refobj->symtab + symnum; 1986 name = refobj->strtab + ref->st_name; 1987 def = NULL; 1988 defobj = NULL; 1989 ve = NULL; 1990 1991 /* 1992 * We don't have to do a full scale lookup if the symbol is local. 1993 * We know it will bind to the instance in this load module; to 1994 * which we already have a pointer (ie ref). By not doing a lookup, 1995 * we not only improve performance, but it also avoids unresolvable 1996 * symbols when local symbols are not in the hash table. This has 1997 * been seen with the ia64 toolchain. 1998 */ 1999 if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) { 2000 if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) { 2001 _rtld_error("%s: Bogus symbol table entry %lu", refobj->path, 2002 symnum); 2003 } 2004 symlook_init(&req, name); 2005 req.flags = flags; 2006 ve = req.ventry = fetch_ventry(refobj, symnum); 2007 req.lockstate = lockstate; 2008 res = symlook_default(&req, refobj); 2009 if (res == 0) { 2010 def = req.sym_out; 2011 defobj = req.defobj_out; 2012 } 2013 } else { 2014 def = ref; 2015 defobj = refobj; 2016 } 2017 2018 /* 2019 * If we found no definition and the reference is weak, treat the 2020 * symbol as having the value zero. 2021 */ 2022 if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) { 2023 def = &sym_zero; 2024 defobj = obj_main; 2025 } 2026 2027 if (def != NULL) { 2028 *defobj_out = defobj; 2029 /* Record the information in the cache to avoid subsequent lookups. */ 2030 if (cache != NULL) { 2031 cache[symnum].sym = def; 2032 cache[symnum].obj = defobj; 2033 } 2034 } else { 2035 if (refobj != &obj_rtld) 2036 _rtld_error("%s: Undefined symbol \"%s%s%s\"", refobj->path, name, 2037 ve != NULL ? "@" : "", ve != NULL ? ve->name : ""); 2038 } 2039 return (def); 2040 } 2041 2042 /* 2043 * Return the search path from the ldconfig hints file, reading it if 2044 * necessary. If nostdlib is true, then the default search paths are 2045 * not added to result. 2046 * 2047 * Returns NULL if there are problems with the hints file, 2048 * or if the search path there is empty. 2049 */ 2050 static const char * 2051 gethints(bool nostdlib) 2052 { 2053 static char *filtered_path; 2054 static const char *hints; 2055 static struct elfhints_hdr hdr; 2056 struct fill_search_info_args sargs, hargs; 2057 struct dl_serinfo smeta, hmeta, *SLPinfo, *hintinfo; 2058 struct dl_serpath *SLPpath, *hintpath; 2059 char *p; 2060 struct stat hint_stat; 2061 unsigned int SLPndx, hintndx, fndx, fcount; 2062 int fd; 2063 size_t flen; 2064 uint32_t dl; 2065 bool skip; 2066 2067 /* First call, read the hints file */ 2068 if (hints == NULL) { 2069 /* Keep from trying again in case the hints file is bad. */ 2070 hints = ""; 2071 2072 if ((fd = open(ld_elf_hints_path, O_RDONLY | O_CLOEXEC)) == -1) 2073 return (NULL); 2074 2075 /* 2076 * Check of hdr.dirlistlen value against type limit 2077 * intends to pacify static analyzers. Further 2078 * paranoia leads to checks that dirlist is fully 2079 * contained in the file range. 2080 */ 2081 if (read(fd, &hdr, sizeof hdr) != sizeof hdr || 2082 hdr.magic != ELFHINTS_MAGIC || 2083 hdr.version != 1 || hdr.dirlistlen > UINT_MAX / 2 || 2084 fstat(fd, &hint_stat) == -1) { 2085 cleanup1: 2086 close(fd); 2087 hdr.dirlistlen = 0; 2088 return (NULL); 2089 } 2090 dl = hdr.strtab; 2091 if (dl + hdr.dirlist < dl) 2092 goto cleanup1; 2093 dl += hdr.dirlist; 2094 if (dl + hdr.dirlistlen < dl) 2095 goto cleanup1; 2096 dl += hdr.dirlistlen; 2097 if (dl > hint_stat.st_size) 2098 goto cleanup1; 2099 p = xmalloc(hdr.dirlistlen + 1); 2100 if (pread(fd, p, hdr.dirlistlen + 1, 2101 hdr.strtab + hdr.dirlist) != (ssize_t)hdr.dirlistlen + 1 || 2102 p[hdr.dirlistlen] != '\0') { 2103 free(p); 2104 goto cleanup1; 2105 } 2106 hints = p; 2107 close(fd); 2108 } 2109 2110 /* 2111 * If caller agreed to receive list which includes the default 2112 * paths, we are done. Otherwise, if we still did not 2113 * calculated filtered result, do it now. 2114 */ 2115 if (!nostdlib) 2116 return (hints[0] != '\0' ? hints : NULL); 2117 if (filtered_path != NULL) 2118 goto filt_ret; 2119 2120 /* 2121 * Obtain the list of all configured search paths, and the 2122 * list of the default paths. 2123 * 2124 * First estimate the size of the results. 2125 */ 2126 smeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 2127 smeta.dls_cnt = 0; 2128 hmeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 2129 hmeta.dls_cnt = 0; 2130 2131 sargs.request = RTLD_DI_SERINFOSIZE; 2132 sargs.serinfo = &smeta; 2133 hargs.request = RTLD_DI_SERINFOSIZE; 2134 hargs.serinfo = &hmeta; 2135 2136 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 2137 &sargs); 2138 path_enumerate(hints, fill_search_info, NULL, &hargs); 2139 2140 SLPinfo = xmalloc(smeta.dls_size); 2141 hintinfo = xmalloc(hmeta.dls_size); 2142 2143 /* 2144 * Next fetch both sets of paths. 2145 */ 2146 sargs.request = RTLD_DI_SERINFO; 2147 sargs.serinfo = SLPinfo; 2148 sargs.serpath = &SLPinfo->dls_serpath[0]; 2149 sargs.strspace = (char *)&SLPinfo->dls_serpath[smeta.dls_cnt]; 2150 2151 hargs.request = RTLD_DI_SERINFO; 2152 hargs.serinfo = hintinfo; 2153 hargs.serpath = &hintinfo->dls_serpath[0]; 2154 hargs.strspace = (char *)&hintinfo->dls_serpath[hmeta.dls_cnt]; 2155 2156 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 2157 &sargs); 2158 path_enumerate(hints, fill_search_info, NULL, &hargs); 2159 2160 /* 2161 * Now calculate the difference between two sets, by excluding 2162 * standard paths from the full set. 2163 */ 2164 fndx = 0; 2165 fcount = 0; 2166 filtered_path = xmalloc(hdr.dirlistlen + 1); 2167 hintpath = &hintinfo->dls_serpath[0]; 2168 for (hintndx = 0; hintndx < hmeta.dls_cnt; hintndx++, hintpath++) { 2169 skip = false; 2170 SLPpath = &SLPinfo->dls_serpath[0]; 2171 /* 2172 * Check each standard path against current. 2173 */ 2174 for (SLPndx = 0; SLPndx < smeta.dls_cnt; SLPndx++, SLPpath++) { 2175 /* matched, skip the path */ 2176 if (!strcmp(hintpath->dls_name, SLPpath->dls_name)) { 2177 skip = true; 2178 break; 2179 } 2180 } 2181 if (skip) 2182 continue; 2183 /* 2184 * Not matched against any standard path, add the path 2185 * to result. Separate consequtive paths with ':'. 2186 */ 2187 if (fcount > 0) { 2188 filtered_path[fndx] = ':'; 2189 fndx++; 2190 } 2191 fcount++; 2192 flen = strlen(hintpath->dls_name); 2193 strncpy((filtered_path + fndx), hintpath->dls_name, flen); 2194 fndx += flen; 2195 } 2196 filtered_path[fndx] = '\0'; 2197 2198 free(SLPinfo); 2199 free(hintinfo); 2200 2201 filt_ret: 2202 return (filtered_path[0] != '\0' ? filtered_path : NULL); 2203 } 2204 2205 static void 2206 init_dag(Obj_Entry *root) 2207 { 2208 const Needed_Entry *needed; 2209 const Objlist_Entry *elm; 2210 DoneList donelist; 2211 2212 if (root->dag_inited) 2213 return; 2214 donelist_init(&donelist); 2215 2216 /* Root object belongs to own DAG. */ 2217 objlist_push_tail(&root->dldags, root); 2218 objlist_push_tail(&root->dagmembers, root); 2219 donelist_check(&donelist, root); 2220 2221 /* 2222 * Add dependencies of root object to DAG in breadth order 2223 * by exploiting the fact that each new object get added 2224 * to the tail of the dagmembers list. 2225 */ 2226 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2227 for (needed = elm->obj->needed; needed != NULL; needed = needed->next) { 2228 if (needed->obj == NULL || donelist_check(&donelist, needed->obj)) 2229 continue; 2230 objlist_push_tail(&needed->obj->dldags, root); 2231 objlist_push_tail(&root->dagmembers, needed->obj); 2232 } 2233 } 2234 root->dag_inited = true; 2235 } 2236 2237 static void 2238 init_marker(Obj_Entry *marker) 2239 { 2240 2241 bzero(marker, sizeof(*marker)); 2242 marker->marker = true; 2243 } 2244 2245 Obj_Entry * 2246 globallist_curr(const Obj_Entry *obj) 2247 { 2248 2249 for (;;) { 2250 if (obj == NULL) 2251 return (NULL); 2252 if (!obj->marker) 2253 return (__DECONST(Obj_Entry *, obj)); 2254 obj = TAILQ_PREV(obj, obj_entry_q, next); 2255 } 2256 } 2257 2258 Obj_Entry * 2259 globallist_next(const Obj_Entry *obj) 2260 { 2261 2262 for (;;) { 2263 obj = TAILQ_NEXT(obj, next); 2264 if (obj == NULL) 2265 return (NULL); 2266 if (!obj->marker) 2267 return (__DECONST(Obj_Entry *, obj)); 2268 } 2269 } 2270 2271 /* Prevent the object from being unmapped while the bind lock is dropped. */ 2272 static void 2273 hold_object(Obj_Entry *obj) 2274 { 2275 2276 obj->holdcount++; 2277 } 2278 2279 static void 2280 unhold_object(Obj_Entry *obj) 2281 { 2282 2283 assert(obj->holdcount > 0); 2284 if (--obj->holdcount == 0 && obj->unholdfree) 2285 release_object(obj); 2286 } 2287 2288 static void 2289 process_z(Obj_Entry *root) 2290 { 2291 const Objlist_Entry *elm; 2292 Obj_Entry *obj; 2293 2294 /* 2295 * Walk over object DAG and process every dependent object 2296 * that is marked as DF_1_NODELETE or DF_1_GLOBAL. They need 2297 * to grow their own DAG. 2298 * 2299 * For DF_1_GLOBAL, DAG is required for symbol lookups in 2300 * symlook_global() to work. 2301 * 2302 * For DF_1_NODELETE, the DAG should have its reference upped. 2303 */ 2304 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2305 obj = elm->obj; 2306 if (obj == NULL) 2307 continue; 2308 if (obj->z_nodelete && !obj->ref_nodel) { 2309 dbg("obj %s -z nodelete", obj->path); 2310 init_dag(obj); 2311 ref_dag(obj); 2312 obj->ref_nodel = true; 2313 } 2314 if (obj->z_global && objlist_find(&list_global, obj) == NULL) { 2315 dbg("obj %s -z global", obj->path); 2316 objlist_push_tail(&list_global, obj); 2317 init_dag(obj); 2318 } 2319 } 2320 } 2321 2322 static void 2323 parse_rtld_phdr(Obj_Entry *obj) 2324 { 2325 const Elf_Phdr *ph; 2326 Elf_Addr note_start, note_end; 2327 2328 obj->stack_flags = PF_X | PF_R | PF_W; 2329 for (ph = obj->phdr; (const char *)ph < (const char *)obj->phdr + 2330 obj->phsize; ph++) { 2331 switch (ph->p_type) { 2332 case PT_GNU_STACK: 2333 obj->stack_flags = ph->p_flags; 2334 break; 2335 case PT_GNU_RELRO: 2336 obj->relro_page = obj->relocbase + 2337 rtld_trunc_page(ph->p_vaddr); 2338 obj->relro_size = rtld_round_page(ph->p_memsz); 2339 break; 2340 case PT_NOTE: 2341 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; 2342 note_end = note_start + ph->p_filesz; 2343 digest_notes(obj, note_start, note_end); 2344 break; 2345 } 2346 } 2347 } 2348 2349 /* 2350 * Initialize the dynamic linker. The argument is the address at which 2351 * the dynamic linker has been mapped into memory. The primary task of 2352 * this function is to relocate the dynamic linker. 2353 */ 2354 static void 2355 init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info) 2356 { 2357 Obj_Entry objtmp; /* Temporary rtld object */ 2358 const Elf_Ehdr *ehdr; 2359 const Elf_Dyn *dyn_rpath; 2360 const Elf_Dyn *dyn_soname; 2361 const Elf_Dyn *dyn_runpath; 2362 2363 #ifdef RTLD_INIT_PAGESIZES_EARLY 2364 /* The page size is required by the dynamic memory allocator. */ 2365 init_pagesizes(aux_info); 2366 #endif 2367 2368 /* 2369 * Conjure up an Obj_Entry structure for the dynamic linker. 2370 * 2371 * The "path" member can't be initialized yet because string constants 2372 * cannot yet be accessed. Below we will set it correctly. 2373 */ 2374 memset(&objtmp, 0, sizeof(objtmp)); 2375 objtmp.path = NULL; 2376 objtmp.rtld = true; 2377 objtmp.mapbase = mapbase; 2378 #ifdef PIC 2379 objtmp.relocbase = mapbase; 2380 #endif 2381 2382 objtmp.dynamic = rtld_dynamic(&objtmp); 2383 digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname, &dyn_runpath); 2384 assert(objtmp.needed == NULL); 2385 assert(!objtmp.textrel); 2386 /* 2387 * Temporarily put the dynamic linker entry into the object list, so 2388 * that symbols can be found. 2389 */ 2390 relocate_objects(&objtmp, true, &objtmp, 0, NULL); 2391 2392 ehdr = (Elf_Ehdr *)mapbase; 2393 objtmp.phdr = (Elf_Phdr *)((char *)mapbase + ehdr->e_phoff); 2394 objtmp.phsize = ehdr->e_phnum * sizeof(objtmp.phdr[0]); 2395 2396 /* Initialize the object list. */ 2397 TAILQ_INIT(&obj_list); 2398 2399 /* Now that non-local variables can be accesses, copy out obj_rtld. */ 2400 memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld)); 2401 2402 #ifndef RTLD_INIT_PAGESIZES_EARLY 2403 /* The page size is required by the dynamic memory allocator. */ 2404 init_pagesizes(aux_info); 2405 #endif 2406 2407 if (aux_info[AT_OSRELDATE] != NULL) 2408 osreldate = aux_info[AT_OSRELDATE]->a_un.a_val; 2409 2410 digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname, dyn_runpath); 2411 2412 /* Replace the path with a dynamically allocated copy. */ 2413 obj_rtld.path = xstrdup(ld_path_rtld); 2414 2415 parse_rtld_phdr(&obj_rtld); 2416 if (obj_enforce_relro(&obj_rtld) == -1) 2417 rtld_die(); 2418 2419 r_debug.r_version = R_DEBUG_VERSION; 2420 r_debug.r_brk = r_debug_state; 2421 r_debug.r_state = RT_CONSISTENT; 2422 r_debug.r_ldbase = obj_rtld.relocbase; 2423 } 2424 2425 /* 2426 * Retrieve the array of supported page sizes. The kernel provides the page 2427 * sizes in increasing order. 2428 */ 2429 static void 2430 init_pagesizes(Elf_Auxinfo **aux_info) 2431 { 2432 static size_t psa[MAXPAGESIZES]; 2433 int mib[2]; 2434 size_t len, size; 2435 2436 if (aux_info[AT_PAGESIZES] != NULL && aux_info[AT_PAGESIZESLEN] != 2437 NULL) { 2438 size = aux_info[AT_PAGESIZESLEN]->a_un.a_val; 2439 pagesizes = aux_info[AT_PAGESIZES]->a_un.a_ptr; 2440 } else { 2441 len = 2; 2442 if (sysctlnametomib("hw.pagesizes", mib, &len) == 0) 2443 size = sizeof(psa); 2444 else { 2445 /* As a fallback, retrieve the base page size. */ 2446 size = sizeof(psa[0]); 2447 if (aux_info[AT_PAGESZ] != NULL) { 2448 psa[0] = aux_info[AT_PAGESZ]->a_un.a_val; 2449 goto psa_filled; 2450 } else { 2451 mib[0] = CTL_HW; 2452 mib[1] = HW_PAGESIZE; 2453 len = 2; 2454 } 2455 } 2456 if (sysctl(mib, len, psa, &size, NULL, 0) == -1) { 2457 _rtld_error("sysctl for hw.pagesize(s) failed"); 2458 rtld_die(); 2459 } 2460 psa_filled: 2461 pagesizes = psa; 2462 } 2463 npagesizes = size / sizeof(pagesizes[0]); 2464 /* Discard any invalid entries at the end of the array. */ 2465 while (npagesizes > 0 && pagesizes[npagesizes - 1] == 0) 2466 npagesizes--; 2467 2468 page_size = pagesizes[0]; 2469 } 2470 2471 /* 2472 * Add the init functions from a needed object list (and its recursive 2473 * needed objects) to "list". This is not used directly; it is a helper 2474 * function for initlist_add_objects(). The write lock must be held 2475 * when this function is called. 2476 */ 2477 static void 2478 initlist_add_neededs(Needed_Entry *needed, Objlist *list) 2479 { 2480 /* Recursively process the successor needed objects. */ 2481 if (needed->next != NULL) 2482 initlist_add_neededs(needed->next, list); 2483 2484 /* Process the current needed object. */ 2485 if (needed->obj != NULL) 2486 initlist_add_objects(needed->obj, needed->obj, list); 2487 } 2488 2489 /* 2490 * Scan all of the DAGs rooted in the range of objects from "obj" to 2491 * "tail" and add their init functions to "list". This recurses over 2492 * the DAGs and ensure the proper init ordering such that each object's 2493 * needed libraries are initialized before the object itself. At the 2494 * same time, this function adds the objects to the global finalization 2495 * list "list_fini" in the opposite order. The write lock must be 2496 * held when this function is called. 2497 */ 2498 static void 2499 initlist_add_objects(Obj_Entry *obj, Obj_Entry *tail, Objlist *list) 2500 { 2501 Obj_Entry *nobj; 2502 2503 if (obj->init_scanned || obj->init_done) 2504 return; 2505 obj->init_scanned = true; 2506 2507 /* Recursively process the successor objects. */ 2508 nobj = globallist_next(obj); 2509 if (nobj != NULL && obj != tail) 2510 initlist_add_objects(nobj, tail, list); 2511 2512 /* Recursively process the needed objects. */ 2513 if (obj->needed != NULL) 2514 initlist_add_neededs(obj->needed, list); 2515 if (obj->needed_filtees != NULL) 2516 initlist_add_neededs(obj->needed_filtees, list); 2517 if (obj->needed_aux_filtees != NULL) 2518 initlist_add_neededs(obj->needed_aux_filtees, list); 2519 2520 /* Add the object to the init list. */ 2521 objlist_push_tail(list, obj); 2522 2523 /* Add the object to the global fini list in the reverse order. */ 2524 if ((obj->fini != (Elf_Addr)NULL || obj->fini_array != (Elf_Addr)NULL) 2525 && !obj->on_fini_list) { 2526 objlist_push_head(&list_fini, obj); 2527 obj->on_fini_list = true; 2528 } 2529 } 2530 2531 static void 2532 free_needed_filtees(Needed_Entry *n, RtldLockState *lockstate) 2533 { 2534 Needed_Entry *needed, *needed1; 2535 2536 for (needed = n; needed != NULL; needed = needed->next) { 2537 if (needed->obj != NULL) { 2538 dlclose_locked(needed->obj, lockstate); 2539 needed->obj = NULL; 2540 } 2541 } 2542 for (needed = n; needed != NULL; needed = needed1) { 2543 needed1 = needed->next; 2544 free(needed); 2545 } 2546 } 2547 2548 static void 2549 unload_filtees(Obj_Entry *obj, RtldLockState *lockstate) 2550 { 2551 2552 free_needed_filtees(obj->needed_filtees, lockstate); 2553 obj->needed_filtees = NULL; 2554 free_needed_filtees(obj->needed_aux_filtees, lockstate); 2555 obj->needed_aux_filtees = NULL; 2556 obj->filtees_loaded = false; 2557 } 2558 2559 static void 2560 load_filtee1(Obj_Entry *obj, Needed_Entry *needed, int flags, 2561 RtldLockState *lockstate) 2562 { 2563 2564 for (; needed != NULL; needed = needed->next) { 2565 needed->obj = dlopen_object(obj->strtab + needed->name, -1, obj, 2566 flags, ((ld_loadfltr || obj->z_loadfltr) ? RTLD_NOW : RTLD_LAZY) | 2567 RTLD_LOCAL, lockstate); 2568 } 2569 } 2570 2571 static void 2572 load_filtees(Obj_Entry *obj, int flags, RtldLockState *lockstate) 2573 { 2574 2575 lock_restart_for_upgrade(lockstate); 2576 if (!obj->filtees_loaded) { 2577 load_filtee1(obj, obj->needed_filtees, flags, lockstate); 2578 load_filtee1(obj, obj->needed_aux_filtees, flags, lockstate); 2579 obj->filtees_loaded = true; 2580 } 2581 } 2582 2583 static int 2584 process_needed(Obj_Entry *obj, Needed_Entry *needed, int flags) 2585 { 2586 Obj_Entry *obj1; 2587 2588 for (; needed != NULL; needed = needed->next) { 2589 obj1 = needed->obj = load_object(obj->strtab + needed->name, -1, obj, 2590 flags & ~RTLD_LO_NOLOAD); 2591 if (obj1 == NULL && !ld_tracing && (flags & RTLD_LO_FILTEES) == 0) 2592 return (-1); 2593 } 2594 return (0); 2595 } 2596 2597 /* 2598 * Given a shared object, traverse its list of needed objects, and load 2599 * each of them. Returns 0 on success. Generates an error message and 2600 * returns -1 on failure. 2601 */ 2602 static int 2603 load_needed_objects(Obj_Entry *first, int flags) 2604 { 2605 Obj_Entry *obj; 2606 2607 for (obj = first; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 2608 if (obj->marker) 2609 continue; 2610 if (process_needed(obj, obj->needed, flags) == -1) 2611 return (-1); 2612 } 2613 return (0); 2614 } 2615 2616 static int 2617 load_preload_objects(const char *penv, bool isfd) 2618 { 2619 Obj_Entry *obj; 2620 const char *name; 2621 size_t len; 2622 char savech, *p, *psave; 2623 int fd; 2624 static const char delim[] = " \t:;"; 2625 2626 if (penv == NULL) 2627 return (0); 2628 2629 p = psave = xstrdup(penv); 2630 p += strspn(p, delim); 2631 while (*p != '\0') { 2632 len = strcspn(p, delim); 2633 2634 savech = p[len]; 2635 p[len] = '\0'; 2636 if (isfd) { 2637 name = NULL; 2638 fd = parse_integer(p); 2639 if (fd == -1) { 2640 free(psave); 2641 return (-1); 2642 } 2643 } else { 2644 name = p; 2645 fd = -1; 2646 } 2647 2648 obj = load_object(name, fd, NULL, 0); 2649 if (obj == NULL) { 2650 free(psave); 2651 return (-1); /* XXX - cleanup */ 2652 } 2653 obj->z_interpose = true; 2654 p[len] = savech; 2655 p += len; 2656 p += strspn(p, delim); 2657 } 2658 LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL); 2659 2660 free(psave); 2661 return (0); 2662 } 2663 2664 static const char * 2665 printable_path(const char *path) 2666 { 2667 2668 return (path == NULL ? "<unknown>" : path); 2669 } 2670 2671 /* 2672 * Load a shared object into memory, if it is not already loaded. The 2673 * object may be specified by name or by user-supplied file descriptor 2674 * fd_u. In the later case, the fd_u descriptor is not closed, but its 2675 * duplicate is. 2676 * 2677 * Returns a pointer to the Obj_Entry for the object. Returns NULL 2678 * on failure. 2679 */ 2680 static Obj_Entry * 2681 load_object(const char *name, int fd_u, const Obj_Entry *refobj, int flags) 2682 { 2683 Obj_Entry *obj; 2684 int fd; 2685 struct stat sb; 2686 char *path; 2687 2688 fd = -1; 2689 if (name != NULL) { 2690 TAILQ_FOREACH(obj, &obj_list, next) { 2691 if (obj->marker || obj->doomed) 2692 continue; 2693 if (object_match_name(obj, name)) 2694 return (obj); 2695 } 2696 2697 path = find_library(name, refobj, &fd); 2698 if (path == NULL) 2699 return (NULL); 2700 } else 2701 path = NULL; 2702 2703 if (fd >= 0) { 2704 /* 2705 * search_library_pathfds() opens a fresh file descriptor for the 2706 * library, so there is no need to dup(). 2707 */ 2708 } else if (fd_u == -1) { 2709 /* 2710 * If we didn't find a match by pathname, or the name is not 2711 * supplied, open the file and check again by device and inode. 2712 * This avoids false mismatches caused by multiple links or ".." 2713 * in pathnames. 2714 * 2715 * To avoid a race, we open the file and use fstat() rather than 2716 * using stat(). 2717 */ 2718 if ((fd = open(path, O_RDONLY | O_CLOEXEC | O_VERIFY)) == -1) { 2719 _rtld_error("Cannot open \"%s\"", path); 2720 free(path); 2721 return (NULL); 2722 } 2723 } else { 2724 fd = fcntl(fd_u, F_DUPFD_CLOEXEC, 0); 2725 if (fd == -1) { 2726 _rtld_error("Cannot dup fd"); 2727 free(path); 2728 return (NULL); 2729 } 2730 } 2731 if (fstat(fd, &sb) == -1) { 2732 _rtld_error("Cannot fstat \"%s\"", printable_path(path)); 2733 close(fd); 2734 free(path); 2735 return (NULL); 2736 } 2737 TAILQ_FOREACH(obj, &obj_list, next) { 2738 if (obj->marker || obj->doomed) 2739 continue; 2740 if (obj->ino == sb.st_ino && obj->dev == sb.st_dev) 2741 break; 2742 } 2743 if (obj != NULL && name != NULL) { 2744 object_add_name(obj, name); 2745 free(path); 2746 close(fd); 2747 return (obj); 2748 } 2749 if (flags & RTLD_LO_NOLOAD) { 2750 free(path); 2751 close(fd); 2752 return (NULL); 2753 } 2754 2755 /* First use of this object, so we must map it in */ 2756 obj = do_load_object(fd, name, path, &sb, flags); 2757 if (obj == NULL) 2758 free(path); 2759 close(fd); 2760 2761 return (obj); 2762 } 2763 2764 static Obj_Entry * 2765 do_load_object(int fd, const char *name, char *path, struct stat *sbp, 2766 int flags) 2767 { 2768 Obj_Entry *obj; 2769 struct statfs fs; 2770 2771 /* 2772 * First, make sure that environment variables haven't been 2773 * used to circumvent the noexec flag on a filesystem. 2774 * We ignore fstatfs(2) failures, since fd might reference 2775 * not a file, e.g. shmfd. 2776 */ 2777 if (dangerous_ld_env && fstatfs(fd, &fs) == 0 && 2778 (fs.f_flags & MNT_NOEXEC) != 0) { 2779 _rtld_error("Cannot execute objects on %s", fs.f_mntonname); 2780 return (NULL); 2781 } 2782 2783 dbg("loading \"%s\"", printable_path(path)); 2784 obj = map_object(fd, printable_path(path), sbp); 2785 if (obj == NULL) 2786 return (NULL); 2787 2788 /* 2789 * If DT_SONAME is present in the object, digest_dynamic2 already 2790 * added it to the object names. 2791 */ 2792 if (name != NULL) 2793 object_add_name(obj, name); 2794 obj->path = path; 2795 if (!digest_dynamic(obj, 0)) 2796 goto errp; 2797 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", obj->path, 2798 obj->valid_hash_sysv, obj->valid_hash_gnu, obj->dynsymcount); 2799 if (obj->z_pie && (flags & RTLD_LO_TRACE) == 0) { 2800 dbg("refusing to load PIE executable \"%s\"", obj->path); 2801 _rtld_error("Cannot load PIE binary %s as DSO", obj->path); 2802 goto errp; 2803 } 2804 if (obj->z_noopen && (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) == 2805 RTLD_LO_DLOPEN) { 2806 dbg("refusing to load non-loadable \"%s\"", obj->path); 2807 _rtld_error("Cannot dlopen non-loadable %s", obj->path); 2808 goto errp; 2809 } 2810 2811 obj->dlopened = (flags & RTLD_LO_DLOPEN) != 0; 2812 TAILQ_INSERT_TAIL(&obj_list, obj, next); 2813 obj_count++; 2814 obj_loads++; 2815 linkmap_add(obj); /* for GDB & dlinfo() */ 2816 max_stack_flags |= obj->stack_flags; 2817 2818 dbg(" %p .. %p: %s", obj->mapbase, 2819 obj->mapbase + obj->mapsize - 1, obj->path); 2820 if (obj->textrel) 2821 dbg(" WARNING: %s has impure text", obj->path); 2822 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 2823 obj->path); 2824 2825 return (obj); 2826 2827 errp: 2828 munmap(obj->mapbase, obj->mapsize); 2829 obj_free(obj); 2830 return (NULL); 2831 } 2832 2833 static int 2834 load_kpreload(const void *addr) 2835 { 2836 Obj_Entry *obj; 2837 const Elf_Ehdr *ehdr; 2838 const Elf_Phdr *phdr, *phlimit, *phdyn, *seg0, *segn; 2839 static const char kname[] = "[vdso]"; 2840 2841 ehdr = addr; 2842 if (!check_elf_headers(ehdr, "kpreload")) 2843 return (-1); 2844 obj = obj_new(); 2845 phdr = (const Elf_Phdr *)((const char *)addr + ehdr->e_phoff); 2846 obj->phdr = phdr; 2847 obj->phsize = ehdr->e_phnum * sizeof(*phdr); 2848 phlimit = phdr + ehdr->e_phnum; 2849 seg0 = segn = NULL; 2850 2851 for (; phdr < phlimit; phdr++) { 2852 switch (phdr->p_type) { 2853 case PT_DYNAMIC: 2854 phdyn = phdr; 2855 break; 2856 case PT_GNU_STACK: 2857 /* Absense of PT_GNU_STACK implies stack_flags == 0. */ 2858 obj->stack_flags = phdr->p_flags; 2859 break; 2860 case PT_LOAD: 2861 if (seg0 == NULL || seg0->p_vaddr > phdr->p_vaddr) 2862 seg0 = phdr; 2863 if (segn == NULL || segn->p_vaddr + segn->p_memsz < 2864 phdr->p_vaddr + phdr->p_memsz) 2865 segn = phdr; 2866 break; 2867 } 2868 } 2869 2870 obj->mapbase = __DECONST(caddr_t, addr); 2871 obj->mapsize = segn->p_vaddr + segn->p_memsz - (Elf_Addr)addr; 2872 obj->vaddrbase = 0; 2873 obj->relocbase = obj->mapbase; 2874 2875 object_add_name(obj, kname); 2876 obj->path = xstrdup(kname); 2877 obj->dynamic = (const Elf_Dyn *)(obj->relocbase + phdyn->p_vaddr); 2878 2879 if (!digest_dynamic(obj, 0)) { 2880 obj_free(obj); 2881 return (-1); 2882 } 2883 2884 /* 2885 * We assume that kernel-preloaded object does not need 2886 * relocation. It is currently written into read-only page, 2887 * handling relocations would mean we need to allocate at 2888 * least one additional page per AS. 2889 */ 2890 dbg("%s mapbase %p phdrs %p PT_LOAD phdr %p vaddr %p dynamic %p", 2891 obj->path, obj->mapbase, obj->phdr, seg0, 2892 obj->relocbase + seg0->p_vaddr, obj->dynamic); 2893 2894 TAILQ_INSERT_TAIL(&obj_list, obj, next); 2895 obj_count++; 2896 obj_loads++; 2897 linkmap_add(obj); /* for GDB & dlinfo() */ 2898 max_stack_flags |= obj->stack_flags; 2899 2900 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, 0, 0, obj->path); 2901 return (0); 2902 } 2903 2904 Obj_Entry * 2905 obj_from_addr(const void *addr) 2906 { 2907 Obj_Entry *obj; 2908 2909 TAILQ_FOREACH(obj, &obj_list, next) { 2910 if (obj->marker) 2911 continue; 2912 if (addr < (void *) obj->mapbase) 2913 continue; 2914 if (addr < (void *)(obj->mapbase + obj->mapsize)) 2915 return obj; 2916 } 2917 return (NULL); 2918 } 2919 2920 static void 2921 preinit_main(void) 2922 { 2923 Elf_Addr *preinit_addr; 2924 int index; 2925 2926 preinit_addr = (Elf_Addr *)obj_main->preinit_array; 2927 if (preinit_addr == NULL) 2928 return; 2929 2930 for (index = 0; index < obj_main->preinit_array_num; index++) { 2931 if (preinit_addr[index] != 0 && preinit_addr[index] != 1) { 2932 dbg("calling preinit function for %s at %p", obj_main->path, 2933 (void *)preinit_addr[index]); 2934 LD_UTRACE(UTRACE_INIT_CALL, obj_main, (void *)preinit_addr[index], 2935 0, 0, obj_main->path); 2936 call_init_pointer(obj_main, preinit_addr[index]); 2937 } 2938 } 2939 } 2940 2941 /* 2942 * Call the finalization functions for each of the objects in "list" 2943 * belonging to the DAG of "root" and referenced once. If NULL "root" 2944 * is specified, every finalization function will be called regardless 2945 * of the reference count and the list elements won't be freed. All of 2946 * the objects are expected to have non-NULL fini functions. 2947 */ 2948 static void 2949 objlist_call_fini(Objlist *list, Obj_Entry *root, RtldLockState *lockstate) 2950 { 2951 Objlist_Entry *elm; 2952 struct dlerror_save *saved_msg; 2953 Elf_Addr *fini_addr; 2954 int index; 2955 2956 assert(root == NULL || root->refcount == 1); 2957 2958 if (root != NULL) 2959 root->doomed = true; 2960 2961 /* 2962 * Preserve the current error message since a fini function might 2963 * call into the dynamic linker and overwrite it. 2964 */ 2965 saved_msg = errmsg_save(); 2966 do { 2967 STAILQ_FOREACH(elm, list, link) { 2968 if (root != NULL && (elm->obj->refcount != 1 || 2969 objlist_find(&root->dagmembers, elm->obj) == NULL)) 2970 continue; 2971 /* Remove object from fini list to prevent recursive invocation. */ 2972 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 2973 /* Ensure that new references cannot be acquired. */ 2974 elm->obj->doomed = true; 2975 2976 hold_object(elm->obj); 2977 lock_release(rtld_bind_lock, lockstate); 2978 /* 2979 * It is legal to have both DT_FINI and DT_FINI_ARRAY defined. 2980 * When this happens, DT_FINI_ARRAY is processed first. 2981 */ 2982 fini_addr = (Elf_Addr *)elm->obj->fini_array; 2983 if (fini_addr != NULL && elm->obj->fini_array_num > 0) { 2984 for (index = elm->obj->fini_array_num - 1; index >= 0; 2985 index--) { 2986 if (fini_addr[index] != 0 && fini_addr[index] != 1) { 2987 dbg("calling fini function for %s at %p", 2988 elm->obj->path, (void *)fini_addr[index]); 2989 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, 2990 (void *)fini_addr[index], 0, 0, elm->obj->path); 2991 call_initfini_pointer(elm->obj, fini_addr[index]); 2992 } 2993 } 2994 } 2995 if (elm->obj->fini != (Elf_Addr)NULL) { 2996 dbg("calling fini function for %s at %p", elm->obj->path, 2997 (void *)elm->obj->fini); 2998 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, (void *)elm->obj->fini, 2999 0, 0, elm->obj->path); 3000 call_initfini_pointer(elm->obj, elm->obj->fini); 3001 } 3002 wlock_acquire(rtld_bind_lock, lockstate); 3003 unhold_object(elm->obj); 3004 /* No need to free anything if process is going down. */ 3005 if (root != NULL) 3006 free(elm); 3007 /* 3008 * We must restart the list traversal after every fini call 3009 * because a dlclose() call from the fini function or from 3010 * another thread might have modified the reference counts. 3011 */ 3012 break; 3013 } 3014 } while (elm != NULL); 3015 errmsg_restore(saved_msg); 3016 } 3017 3018 /* 3019 * Call the initialization functions for each of the objects in 3020 * "list". All of the objects are expected to have non-NULL init 3021 * functions. 3022 */ 3023 static void 3024 objlist_call_init(Objlist *list, RtldLockState *lockstate) 3025 { 3026 Objlist_Entry *elm; 3027 Obj_Entry *obj; 3028 struct dlerror_save *saved_msg; 3029 Elf_Addr *init_addr; 3030 void (*reg)(void (*)(void)); 3031 int index; 3032 3033 /* 3034 * Clean init_scanned flag so that objects can be rechecked and 3035 * possibly initialized earlier if any of vectors called below 3036 * cause the change by using dlopen. 3037 */ 3038 TAILQ_FOREACH(obj, &obj_list, next) { 3039 if (obj->marker) 3040 continue; 3041 obj->init_scanned = false; 3042 } 3043 3044 /* 3045 * Preserve the current error message since an init function might 3046 * call into the dynamic linker and overwrite it. 3047 */ 3048 saved_msg = errmsg_save(); 3049 STAILQ_FOREACH(elm, list, link) { 3050 if (elm->obj->init_done) /* Initialized early. */ 3051 continue; 3052 /* 3053 * Race: other thread might try to use this object before current 3054 * one completes the initialization. Not much can be done here 3055 * without better locking. 3056 */ 3057 elm->obj->init_done = true; 3058 hold_object(elm->obj); 3059 reg = NULL; 3060 if (elm->obj == obj_main && obj_main->crt_no_init) { 3061 reg = (void (*)(void (*)(void)))get_program_var_addr( 3062 "__libc_atexit", lockstate); 3063 } 3064 lock_release(rtld_bind_lock, lockstate); 3065 if (reg != NULL) { 3066 reg(rtld_exit); 3067 rtld_exit_ptr = rtld_nop_exit; 3068 } 3069 3070 /* 3071 * It is legal to have both DT_INIT and DT_INIT_ARRAY defined. 3072 * When this happens, DT_INIT is processed first. 3073 */ 3074 if (elm->obj->init != (Elf_Addr)NULL) { 3075 dbg("calling init function for %s at %p", elm->obj->path, 3076 (void *)elm->obj->init); 3077 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, (void *)elm->obj->init, 3078 0, 0, elm->obj->path); 3079 call_init_pointer(elm->obj, elm->obj->init); 3080 } 3081 init_addr = (Elf_Addr *)elm->obj->init_array; 3082 if (init_addr != NULL) { 3083 for (index = 0; index < elm->obj->init_array_num; index++) { 3084 if (init_addr[index] != 0 && init_addr[index] != 1) { 3085 dbg("calling init function for %s at %p", elm->obj->path, 3086 (void *)init_addr[index]); 3087 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, 3088 (void *)init_addr[index], 0, 0, elm->obj->path); 3089 call_init_pointer(elm->obj, init_addr[index]); 3090 } 3091 } 3092 } 3093 wlock_acquire(rtld_bind_lock, lockstate); 3094 unhold_object(elm->obj); 3095 } 3096 errmsg_restore(saved_msg); 3097 } 3098 3099 static void 3100 objlist_clear(Objlist *list) 3101 { 3102 Objlist_Entry *elm; 3103 3104 while (!STAILQ_EMPTY(list)) { 3105 elm = STAILQ_FIRST(list); 3106 STAILQ_REMOVE_HEAD(list, link); 3107 free(elm); 3108 } 3109 } 3110 3111 static Objlist_Entry * 3112 objlist_find(Objlist *list, const Obj_Entry *obj) 3113 { 3114 Objlist_Entry *elm; 3115 3116 STAILQ_FOREACH(elm, list, link) 3117 if (elm->obj == obj) 3118 return elm; 3119 return (NULL); 3120 } 3121 3122 static void 3123 objlist_init(Objlist *list) 3124 { 3125 STAILQ_INIT(list); 3126 } 3127 3128 static void 3129 objlist_push_head(Objlist *list, Obj_Entry *obj) 3130 { 3131 Objlist_Entry *elm; 3132 3133 elm = NEW(Objlist_Entry); 3134 elm->obj = obj; 3135 STAILQ_INSERT_HEAD(list, elm, link); 3136 } 3137 3138 static void 3139 objlist_push_tail(Objlist *list, Obj_Entry *obj) 3140 { 3141 Objlist_Entry *elm; 3142 3143 elm = NEW(Objlist_Entry); 3144 elm->obj = obj; 3145 STAILQ_INSERT_TAIL(list, elm, link); 3146 } 3147 3148 static void 3149 objlist_put_after(Objlist *list, Obj_Entry *listobj, Obj_Entry *obj) 3150 { 3151 Objlist_Entry *elm, *listelm; 3152 3153 STAILQ_FOREACH(listelm, list, link) { 3154 if (listelm->obj == listobj) 3155 break; 3156 } 3157 elm = NEW(Objlist_Entry); 3158 elm->obj = obj; 3159 if (listelm != NULL) 3160 STAILQ_INSERT_AFTER(list, listelm, elm, link); 3161 else 3162 STAILQ_INSERT_TAIL(list, elm, link); 3163 } 3164 3165 static void 3166 objlist_remove(Objlist *list, Obj_Entry *obj) 3167 { 3168 Objlist_Entry *elm; 3169 3170 if ((elm = objlist_find(list, obj)) != NULL) { 3171 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 3172 free(elm); 3173 } 3174 } 3175 3176 /* 3177 * Relocate dag rooted in the specified object. 3178 * Returns 0 on success, or -1 on failure. 3179 */ 3180 3181 static int 3182 relocate_object_dag(Obj_Entry *root, bool bind_now, Obj_Entry *rtldobj, 3183 int flags, RtldLockState *lockstate) 3184 { 3185 Objlist_Entry *elm; 3186 int error; 3187 3188 error = 0; 3189 STAILQ_FOREACH(elm, &root->dagmembers, link) { 3190 error = relocate_object(elm->obj, bind_now, rtldobj, flags, 3191 lockstate); 3192 if (error == -1) 3193 break; 3194 } 3195 return (error); 3196 } 3197 3198 /* 3199 * Prepare for, or clean after, relocating an object marked with 3200 * DT_TEXTREL or DF_TEXTREL. Before relocating, all read-only 3201 * segments are remapped read-write. After relocations are done, the 3202 * segment's permissions are returned back to the modes specified in 3203 * the phdrs. If any relocation happened, or always for wired 3204 * program, COW is triggered. 3205 */ 3206 static int 3207 reloc_textrel_prot(Obj_Entry *obj, bool before) 3208 { 3209 const Elf_Phdr *ph; 3210 void *base; 3211 size_t l, sz; 3212 int prot; 3213 3214 for (l = obj->phsize / sizeof(*ph), ph = obj->phdr; l > 0; 3215 l--, ph++) { 3216 if (ph->p_type != PT_LOAD || (ph->p_flags & PF_W) != 0) 3217 continue; 3218 base = obj->relocbase + rtld_trunc_page(ph->p_vaddr); 3219 sz = rtld_round_page(ph->p_vaddr + ph->p_filesz) - 3220 rtld_trunc_page(ph->p_vaddr); 3221 prot = before ? (PROT_READ | PROT_WRITE) : 3222 convert_prot(ph->p_flags); 3223 if (mprotect(base, sz, prot) == -1) { 3224 _rtld_error("%s: Cannot write-%sable text segment: %s", 3225 obj->path, before ? "en" : "dis", 3226 rtld_strerror(errno)); 3227 return (-1); 3228 } 3229 } 3230 return (0); 3231 } 3232 3233 /* Process RELR relative relocations. */ 3234 static void 3235 reloc_relr(Obj_Entry *obj) 3236 { 3237 const Elf_Relr *relr, *relrlim; 3238 Elf_Addr *where; 3239 3240 relrlim = (const Elf_Relr *)((const char *)obj->relr + obj->relrsize); 3241 for (relr = obj->relr; relr < relrlim; relr++) { 3242 Elf_Relr entry = *relr; 3243 3244 if ((entry & 1) == 0) { 3245 where = (Elf_Addr *)(obj->relocbase + entry); 3246 *where++ += (Elf_Addr)obj->relocbase; 3247 } else { 3248 for (long i = 0; (entry >>= 1) != 0; i++) 3249 if ((entry & 1) != 0) 3250 where[i] += (Elf_Addr)obj->relocbase; 3251 where += CHAR_BIT * sizeof(Elf_Relr) - 1; 3252 } 3253 } 3254 } 3255 3256 /* 3257 * Relocate single object. 3258 * Returns 0 on success, or -1 on failure. 3259 */ 3260 static int 3261 relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, 3262 int flags, RtldLockState *lockstate) 3263 { 3264 3265 if (obj->relocated) 3266 return (0); 3267 obj->relocated = true; 3268 if (obj != rtldobj) 3269 dbg("relocating \"%s\"", obj->path); 3270 3271 if (obj->symtab == NULL || obj->strtab == NULL || 3272 !(obj->valid_hash_sysv || obj->valid_hash_gnu)) 3273 dbg("object %s has no run-time symbol table", obj->path); 3274 3275 /* There are relocations to the write-protected text segment. */ 3276 if (obj->textrel && reloc_textrel_prot(obj, true) != 0) 3277 return (-1); 3278 3279 /* Process the non-PLT non-IFUNC relocations. */ 3280 if (reloc_non_plt(obj, rtldobj, flags, lockstate)) 3281 return (-1); 3282 reloc_relr(obj); 3283 3284 /* Re-protected the text segment. */ 3285 if (obj->textrel && reloc_textrel_prot(obj, false) != 0) 3286 return (-1); 3287 3288 /* Set the special PLT or GOT entries. */ 3289 init_pltgot(obj); 3290 3291 /* Process the PLT relocations. */ 3292 if (reloc_plt(obj, flags, lockstate) == -1) 3293 return (-1); 3294 /* Relocate the jump slots if we are doing immediate binding. */ 3295 if ((obj->bind_now || bind_now) && reloc_jmpslots(obj, flags, 3296 lockstate) == -1) 3297 return (-1); 3298 3299 if (!obj->mainprog && obj_enforce_relro(obj) == -1) 3300 return (-1); 3301 3302 /* 3303 * Set up the magic number and version in the Obj_Entry. These 3304 * were checked in the crt1.o from the original ElfKit, so we 3305 * set them for backward compatibility. 3306 */ 3307 obj->magic = RTLD_MAGIC; 3308 obj->version = RTLD_VERSION; 3309 3310 return (0); 3311 } 3312 3313 /* 3314 * Relocate newly-loaded shared objects. The argument is a pointer to 3315 * the Obj_Entry for the first such object. All objects from the first 3316 * to the end of the list of objects are relocated. Returns 0 on success, 3317 * or -1 on failure. 3318 */ 3319 static int 3320 relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj, 3321 int flags, RtldLockState *lockstate) 3322 { 3323 Obj_Entry *obj; 3324 int error; 3325 3326 for (error = 0, obj = first; obj != NULL; 3327 obj = TAILQ_NEXT(obj, next)) { 3328 if (obj->marker) 3329 continue; 3330 error = relocate_object(obj, bind_now, rtldobj, flags, 3331 lockstate); 3332 if (error == -1) 3333 break; 3334 } 3335 return (error); 3336 } 3337 3338 /* 3339 * The handling of R_MACHINE_IRELATIVE relocations and jumpslots 3340 * referencing STT_GNU_IFUNC symbols is postponed till the other 3341 * relocations are done. The indirect functions specified as 3342 * ifunc are allowed to call other symbols, so we need to have 3343 * objects relocated before asking for resolution from indirects. 3344 * 3345 * The R_MACHINE_IRELATIVE slots are resolved in greedy fashion, 3346 * instead of the usual lazy handling of PLT slots. It is 3347 * consistent with how GNU does it. 3348 */ 3349 static int 3350 resolve_object_ifunc(Obj_Entry *obj, bool bind_now, int flags, 3351 RtldLockState *lockstate) 3352 { 3353 3354 if (obj->ifuncs_resolved) 3355 return (0); 3356 obj->ifuncs_resolved = true; 3357 if (!obj->irelative && !obj->irelative_nonplt && 3358 !((obj->bind_now || bind_now) && obj->gnu_ifunc) && 3359 !obj->non_plt_gnu_ifunc) 3360 return (0); 3361 if (obj_disable_relro(obj) == -1 || 3362 (obj->irelative && reloc_iresolve(obj, lockstate) == -1) || 3363 (obj->irelative_nonplt && reloc_iresolve_nonplt(obj, 3364 lockstate) == -1) || 3365 ((obj->bind_now || bind_now) && obj->gnu_ifunc && 3366 reloc_gnu_ifunc(obj, flags, lockstate) == -1) || 3367 (obj->non_plt_gnu_ifunc && reloc_non_plt(obj, &obj_rtld, 3368 flags | SYMLOOK_IFUNC, lockstate) == -1) || 3369 obj_enforce_relro(obj) == -1) 3370 return (-1); 3371 return (0); 3372 } 3373 3374 static int 3375 initlist_objects_ifunc(Objlist *list, bool bind_now, int flags, 3376 RtldLockState *lockstate) 3377 { 3378 Objlist_Entry *elm; 3379 Obj_Entry *obj; 3380 3381 STAILQ_FOREACH(elm, list, link) { 3382 obj = elm->obj; 3383 if (obj->marker) 3384 continue; 3385 if (resolve_object_ifunc(obj, bind_now, flags, 3386 lockstate) == -1) 3387 return (-1); 3388 } 3389 return (0); 3390 } 3391 3392 /* 3393 * Cleanup procedure. It will be called (by the atexit mechanism) just 3394 * before the process exits. 3395 */ 3396 static void 3397 rtld_exit(void) 3398 { 3399 RtldLockState lockstate; 3400 3401 wlock_acquire(rtld_bind_lock, &lockstate); 3402 dbg("rtld_exit()"); 3403 objlist_call_fini(&list_fini, NULL, &lockstate); 3404 /* No need to remove the items from the list, since we are exiting. */ 3405 if (!libmap_disable) 3406 lm_fini(); 3407 lock_release(rtld_bind_lock, &lockstate); 3408 } 3409 3410 static void 3411 rtld_nop_exit(void) 3412 { 3413 } 3414 3415 /* 3416 * Iterate over a search path, translate each element, and invoke the 3417 * callback on the result. 3418 */ 3419 static void * 3420 path_enumerate(const char *path, path_enum_proc callback, 3421 const char *refobj_path, void *arg) 3422 { 3423 const char *trans; 3424 if (path == NULL) 3425 return (NULL); 3426 3427 path += strspn(path, ":;"); 3428 while (*path != '\0') { 3429 size_t len; 3430 char *res; 3431 3432 len = strcspn(path, ":;"); 3433 trans = lm_findn(refobj_path, path, len); 3434 if (trans) 3435 res = callback(trans, strlen(trans), arg); 3436 else 3437 res = callback(path, len, arg); 3438 3439 if (res != NULL) 3440 return (res); 3441 3442 path += len; 3443 path += strspn(path, ":;"); 3444 } 3445 3446 return (NULL); 3447 } 3448 3449 struct try_library_args { 3450 const char *name; 3451 size_t namelen; 3452 char *buffer; 3453 size_t buflen; 3454 int fd; 3455 }; 3456 3457 static void * 3458 try_library_path(const char *dir, size_t dirlen, void *param) 3459 { 3460 struct try_library_args *arg; 3461 int fd; 3462 3463 arg = param; 3464 if (*dir == '/' || trust) { 3465 char *pathname; 3466 3467 if (dirlen + 1 + arg->namelen + 1 > arg->buflen) 3468 return (NULL); 3469 3470 pathname = arg->buffer; 3471 strncpy(pathname, dir, dirlen); 3472 pathname[dirlen] = '/'; 3473 strcpy(pathname + dirlen + 1, arg->name); 3474 3475 dbg(" Trying \"%s\"", pathname); 3476 fd = open(pathname, O_RDONLY | O_CLOEXEC | O_VERIFY); 3477 if (fd >= 0) { 3478 dbg(" Opened \"%s\", fd %d", pathname, fd); 3479 pathname = xmalloc(dirlen + 1 + arg->namelen + 1); 3480 strcpy(pathname, arg->buffer); 3481 arg->fd = fd; 3482 return (pathname); 3483 } else { 3484 dbg(" Failed to open \"%s\": %s", 3485 pathname, rtld_strerror(errno)); 3486 } 3487 } 3488 return (NULL); 3489 } 3490 3491 static char * 3492 search_library_path(const char *name, const char *path, 3493 const char *refobj_path, int *fdp) 3494 { 3495 char *p; 3496 struct try_library_args arg; 3497 3498 if (path == NULL) 3499 return (NULL); 3500 3501 arg.name = name; 3502 arg.namelen = strlen(name); 3503 arg.buffer = xmalloc(PATH_MAX); 3504 arg.buflen = PATH_MAX; 3505 arg.fd = -1; 3506 3507 p = path_enumerate(path, try_library_path, refobj_path, &arg); 3508 *fdp = arg.fd; 3509 3510 free(arg.buffer); 3511 3512 return (p); 3513 } 3514 3515 3516 /* 3517 * Finds the library with the given name using the directory descriptors 3518 * listed in the LD_LIBRARY_PATH_FDS environment variable. 3519 * 3520 * Returns a freshly-opened close-on-exec file descriptor for the library, 3521 * or -1 if the library cannot be found. 3522 */ 3523 static char * 3524 search_library_pathfds(const char *name, const char *path, int *fdp) 3525 { 3526 char *envcopy, *fdstr, *found, *last_token; 3527 size_t len; 3528 int dirfd, fd; 3529 3530 dbg("%s('%s', '%s', fdp)", __func__, name, path); 3531 3532 /* Don't load from user-specified libdirs into setuid binaries. */ 3533 if (!trust) 3534 return (NULL); 3535 3536 /* We can't do anything if LD_LIBRARY_PATH_FDS isn't set. */ 3537 if (path == NULL) 3538 return (NULL); 3539 3540 /* LD_LIBRARY_PATH_FDS only works with relative paths. */ 3541 if (name[0] == '/') { 3542 dbg("Absolute path (%s) passed to %s", name, __func__); 3543 return (NULL); 3544 } 3545 3546 /* 3547 * Use strtok_r() to walk the FD:FD:FD list. This requires a local 3548 * copy of the path, as strtok_r rewrites separator tokens 3549 * with '\0'. 3550 */ 3551 found = NULL; 3552 envcopy = xstrdup(path); 3553 for (fdstr = strtok_r(envcopy, ":", &last_token); fdstr != NULL; 3554 fdstr = strtok_r(NULL, ":", &last_token)) { 3555 dirfd = parse_integer(fdstr); 3556 if (dirfd < 0) { 3557 _rtld_error("failed to parse directory FD: '%s'", 3558 fdstr); 3559 break; 3560 } 3561 fd = __sys_openat(dirfd, name, O_RDONLY | O_CLOEXEC | O_VERIFY); 3562 if (fd >= 0) { 3563 *fdp = fd; 3564 len = strlen(fdstr) + strlen(name) + 3; 3565 found = xmalloc(len); 3566 if (rtld_snprintf(found, len, "#%d/%s", dirfd, name) < 0) { 3567 _rtld_error("error generating '%d/%s'", 3568 dirfd, name); 3569 rtld_die(); 3570 } 3571 dbg("open('%s') => %d", found, fd); 3572 break; 3573 } 3574 } 3575 free(envcopy); 3576 3577 return (found); 3578 } 3579 3580 3581 int 3582 dlclose(void *handle) 3583 { 3584 RtldLockState lockstate; 3585 int error; 3586 3587 wlock_acquire(rtld_bind_lock, &lockstate); 3588 error = dlclose_locked(handle, &lockstate); 3589 lock_release(rtld_bind_lock, &lockstate); 3590 return (error); 3591 } 3592 3593 static int 3594 dlclose_locked(void *handle, RtldLockState *lockstate) 3595 { 3596 Obj_Entry *root; 3597 3598 root = dlcheck(handle); 3599 if (root == NULL) 3600 return (-1); 3601 LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount, 3602 root->path); 3603 3604 /* Unreference the object and its dependencies. */ 3605 root->dl_refcount--; 3606 3607 if (root->refcount == 1) { 3608 /* 3609 * The object will be no longer referenced, so we must unload it. 3610 * First, call the fini functions. 3611 */ 3612 objlist_call_fini(&list_fini, root, lockstate); 3613 3614 unref_dag(root); 3615 3616 /* Finish cleaning up the newly-unreferenced objects. */ 3617 GDB_STATE(RT_DELETE,&root->linkmap); 3618 unload_object(root, lockstate); 3619 GDB_STATE(RT_CONSISTENT,NULL); 3620 } else 3621 unref_dag(root); 3622 3623 LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL); 3624 return (0); 3625 } 3626 3627 char * 3628 dlerror(void) 3629 { 3630 if (*(lockinfo.dlerror_seen()) != 0) 3631 return (NULL); 3632 *lockinfo.dlerror_seen() = 1; 3633 return (lockinfo.dlerror_loc()); 3634 } 3635 3636 /* 3637 * This function is deprecated and has no effect. 3638 */ 3639 void 3640 dllockinit(void *context, 3641 void *(*_lock_create)(void *context) __unused, 3642 void (*_rlock_acquire)(void *lock) __unused, 3643 void (*_wlock_acquire)(void *lock) __unused, 3644 void (*_lock_release)(void *lock) __unused, 3645 void (*_lock_destroy)(void *lock) __unused, 3646 void (*context_destroy)(void *context)) 3647 { 3648 static void *cur_context; 3649 static void (*cur_context_destroy)(void *); 3650 3651 /* Just destroy the context from the previous call, if necessary. */ 3652 if (cur_context_destroy != NULL) 3653 cur_context_destroy(cur_context); 3654 cur_context = context; 3655 cur_context_destroy = context_destroy; 3656 } 3657 3658 void * 3659 dlopen(const char *name, int mode) 3660 { 3661 3662 return (rtld_dlopen(name, -1, mode)); 3663 } 3664 3665 void * 3666 fdlopen(int fd, int mode) 3667 { 3668 3669 return (rtld_dlopen(NULL, fd, mode)); 3670 } 3671 3672 static void * 3673 rtld_dlopen(const char *name, int fd, int mode) 3674 { 3675 RtldLockState lockstate; 3676 int lo_flags; 3677 3678 LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name); 3679 ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1"; 3680 if (ld_tracing != NULL) { 3681 rlock_acquire(rtld_bind_lock, &lockstate); 3682 if (sigsetjmp(lockstate.env, 0) != 0) 3683 lock_upgrade(rtld_bind_lock, &lockstate); 3684 environ = __DECONST(char **, *get_program_var_addr("environ", &lockstate)); 3685 lock_release(rtld_bind_lock, &lockstate); 3686 } 3687 lo_flags = RTLD_LO_DLOPEN; 3688 if (mode & RTLD_NODELETE) 3689 lo_flags |= RTLD_LO_NODELETE; 3690 if (mode & RTLD_NOLOAD) 3691 lo_flags |= RTLD_LO_NOLOAD; 3692 if (mode & RTLD_DEEPBIND) 3693 lo_flags |= RTLD_LO_DEEPBIND; 3694 if (ld_tracing != NULL) 3695 lo_flags |= RTLD_LO_TRACE | RTLD_LO_IGNSTLS; 3696 3697 return (dlopen_object(name, fd, obj_main, lo_flags, 3698 mode & (RTLD_MODEMASK | RTLD_GLOBAL), NULL)); 3699 } 3700 3701 static void 3702 dlopen_cleanup(Obj_Entry *obj, RtldLockState *lockstate) 3703 { 3704 3705 obj->dl_refcount--; 3706 unref_dag(obj); 3707 if (obj->refcount == 0) 3708 unload_object(obj, lockstate); 3709 } 3710 3711 static Obj_Entry * 3712 dlopen_object(const char *name, int fd, Obj_Entry *refobj, int lo_flags, 3713 int mode, RtldLockState *lockstate) 3714 { 3715 Obj_Entry *obj; 3716 Objlist initlist; 3717 RtldLockState mlockstate; 3718 int result; 3719 3720 dbg("dlopen_object name \"%s\" fd %d refobj \"%s\" lo_flags %#x mode %#x", 3721 name != NULL ? name : "<null>", fd, refobj == NULL ? "<null>" : 3722 refobj->path, lo_flags, mode); 3723 objlist_init(&initlist); 3724 3725 if (lockstate == NULL && !(lo_flags & RTLD_LO_EARLY)) { 3726 wlock_acquire(rtld_bind_lock, &mlockstate); 3727 lockstate = &mlockstate; 3728 } 3729 GDB_STATE(RT_ADD,NULL); 3730 3731 obj = NULL; 3732 if (name == NULL && fd == -1) { 3733 obj = obj_main; 3734 obj->refcount++; 3735 } else { 3736 obj = load_object(name, fd, refobj, lo_flags); 3737 } 3738 3739 if (obj) { 3740 obj->dl_refcount++; 3741 if (mode & RTLD_GLOBAL && objlist_find(&list_global, obj) == NULL) 3742 objlist_push_tail(&list_global, obj); 3743 3744 if (!obj->init_done) { 3745 /* We loaded something new and have to init something. */ 3746 if ((lo_flags & RTLD_LO_DEEPBIND) != 0) 3747 obj->symbolic = true; 3748 result = 0; 3749 if ((lo_flags & (RTLD_LO_EARLY | RTLD_LO_IGNSTLS)) == 0 && 3750 obj->static_tls && !allocate_tls_offset(obj)) { 3751 _rtld_error("%s: No space available " 3752 "for static Thread Local Storage", obj->path); 3753 result = -1; 3754 } 3755 if (result != -1) 3756 result = load_needed_objects(obj, lo_flags & (RTLD_LO_DLOPEN | 3757 RTLD_LO_EARLY | RTLD_LO_IGNSTLS | RTLD_LO_TRACE)); 3758 init_dag(obj); 3759 ref_dag(obj); 3760 if (result != -1) 3761 result = rtld_verify_versions(&obj->dagmembers); 3762 if (result != -1 && ld_tracing) 3763 goto trace; 3764 if (result == -1 || relocate_object_dag(obj, 3765 (mode & RTLD_MODEMASK) == RTLD_NOW, &obj_rtld, 3766 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 3767 lockstate) == -1) { 3768 dlopen_cleanup(obj, lockstate); 3769 obj = NULL; 3770 } else if (lo_flags & RTLD_LO_EARLY) { 3771 /* 3772 * Do not call the init functions for early loaded 3773 * filtees. The image is still not initialized enough 3774 * for them to work. 3775 * 3776 * Our object is found by the global object list and 3777 * will be ordered among all init calls done right 3778 * before transferring control to main. 3779 */ 3780 } else { 3781 /* Make list of init functions to call. */ 3782 initlist_add_objects(obj, obj, &initlist); 3783 } 3784 /* 3785 * Process all no_delete or global objects here, given 3786 * them own DAGs to prevent their dependencies from being 3787 * unloaded. This has to be done after we have loaded all 3788 * of the dependencies, so that we do not miss any. 3789 */ 3790 if (obj != NULL) 3791 process_z(obj); 3792 } else { 3793 /* 3794 * Bump the reference counts for objects on this DAG. If 3795 * this is the first dlopen() call for the object that was 3796 * already loaded as a dependency, initialize the dag 3797 * starting at it. 3798 */ 3799 init_dag(obj); 3800 ref_dag(obj); 3801 3802 if ((lo_flags & RTLD_LO_TRACE) != 0) 3803 goto trace; 3804 } 3805 if (obj != NULL && ((lo_flags & RTLD_LO_NODELETE) != 0 || 3806 obj->z_nodelete) && !obj->ref_nodel) { 3807 dbg("obj %s nodelete", obj->path); 3808 ref_dag(obj); 3809 obj->z_nodelete = obj->ref_nodel = true; 3810 } 3811 } 3812 3813 LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0, 3814 name); 3815 GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL); 3816 3817 if ((lo_flags & RTLD_LO_EARLY) == 0) { 3818 map_stacks_exec(lockstate); 3819 if (obj != NULL) 3820 distribute_static_tls(&initlist, lockstate); 3821 } 3822 3823 if (initlist_objects_ifunc(&initlist, (mode & RTLD_MODEMASK) == RTLD_NOW, 3824 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 3825 lockstate) == -1) { 3826 objlist_clear(&initlist); 3827 dlopen_cleanup(obj, lockstate); 3828 if (lockstate == &mlockstate) 3829 lock_release(rtld_bind_lock, lockstate); 3830 return (NULL); 3831 } 3832 3833 if (!(lo_flags & RTLD_LO_EARLY)) { 3834 /* Call the init functions. */ 3835 objlist_call_init(&initlist, lockstate); 3836 } 3837 objlist_clear(&initlist); 3838 if (lockstate == &mlockstate) 3839 lock_release(rtld_bind_lock, lockstate); 3840 return (obj); 3841 trace: 3842 trace_loaded_objects(obj, false); 3843 if (lockstate == &mlockstate) 3844 lock_release(rtld_bind_lock, lockstate); 3845 exit(0); 3846 } 3847 3848 static void * 3849 do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve, 3850 int flags) 3851 { 3852 DoneList donelist; 3853 const Obj_Entry *obj, *defobj; 3854 const Elf_Sym *def; 3855 SymLook req; 3856 RtldLockState lockstate; 3857 tls_index ti; 3858 void *sym; 3859 int res; 3860 3861 def = NULL; 3862 defobj = NULL; 3863 symlook_init(&req, name); 3864 req.ventry = ve; 3865 req.flags = flags | SYMLOOK_IN_PLT; 3866 req.lockstate = &lockstate; 3867 3868 LD_UTRACE(UTRACE_DLSYM_START, handle, NULL, 0, 0, name); 3869 rlock_acquire(rtld_bind_lock, &lockstate); 3870 if (sigsetjmp(lockstate.env, 0) != 0) 3871 lock_upgrade(rtld_bind_lock, &lockstate); 3872 if (handle == NULL || handle == RTLD_NEXT || 3873 handle == RTLD_DEFAULT || handle == RTLD_SELF) { 3874 3875 if ((obj = obj_from_addr(retaddr)) == NULL) { 3876 _rtld_error("Cannot determine caller's shared object"); 3877 lock_release(rtld_bind_lock, &lockstate); 3878 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 3879 return (NULL); 3880 } 3881 if (handle == NULL) { /* Just the caller's shared object. */ 3882 res = symlook_obj(&req, obj); 3883 if (res == 0) { 3884 def = req.sym_out; 3885 defobj = req.defobj_out; 3886 } 3887 } else if (handle == RTLD_NEXT || /* Objects after caller's */ 3888 handle == RTLD_SELF) { /* ... caller included */ 3889 if (handle == RTLD_NEXT) 3890 obj = globallist_next(obj); 3891 for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 3892 if (obj->marker) 3893 continue; 3894 res = symlook_obj(&req, obj); 3895 if (res == 0) { 3896 if (def == NULL || (ld_dynamic_weak && 3897 ELF_ST_BIND(req.sym_out->st_info) != STB_WEAK)) { 3898 def = req.sym_out; 3899 defobj = req.defobj_out; 3900 if (!ld_dynamic_weak || 3901 ELF_ST_BIND(def->st_info) != STB_WEAK) 3902 break; 3903 } 3904 } 3905 } 3906 /* 3907 * Search the dynamic linker itself, and possibly resolve the 3908 * symbol from there. This is how the application links to 3909 * dynamic linker services such as dlopen. 3910 * Note that we ignore ld_dynamic_weak == false case, 3911 * always overriding weak symbols by rtld definitions. 3912 */ 3913 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 3914 res = symlook_obj(&req, &obj_rtld); 3915 if (res == 0) { 3916 def = req.sym_out; 3917 defobj = req.defobj_out; 3918 } 3919 } 3920 } else { 3921 assert(handle == RTLD_DEFAULT); 3922 res = symlook_default(&req, obj); 3923 if (res == 0) { 3924 defobj = req.defobj_out; 3925 def = req.sym_out; 3926 } 3927 } 3928 } else { 3929 if ((obj = dlcheck(handle)) == NULL) { 3930 lock_release(rtld_bind_lock, &lockstate); 3931 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 3932 return (NULL); 3933 } 3934 3935 donelist_init(&donelist); 3936 if (obj->mainprog) { 3937 /* Handle obtained by dlopen(NULL, ...) implies global scope. */ 3938 res = symlook_global(&req, &donelist); 3939 if (res == 0) { 3940 def = req.sym_out; 3941 defobj = req.defobj_out; 3942 } 3943 /* 3944 * Search the dynamic linker itself, and possibly resolve the 3945 * symbol from there. This is how the application links to 3946 * dynamic linker services such as dlopen. 3947 */ 3948 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 3949 res = symlook_obj(&req, &obj_rtld); 3950 if (res == 0) { 3951 def = req.sym_out; 3952 defobj = req.defobj_out; 3953 } 3954 } 3955 } 3956 else { 3957 /* Search the whole DAG rooted at the given object. */ 3958 res = symlook_list(&req, &obj->dagmembers, &donelist); 3959 if (res == 0) { 3960 def = req.sym_out; 3961 defobj = req.defobj_out; 3962 } 3963 } 3964 } 3965 3966 if (def != NULL) { 3967 lock_release(rtld_bind_lock, &lockstate); 3968 3969 /* 3970 * The value required by the caller is derived from the value 3971 * of the symbol. this is simply the relocated value of the 3972 * symbol. 3973 */ 3974 if (ELF_ST_TYPE(def->st_info) == STT_FUNC) 3975 sym = make_function_pointer(def, defobj); 3976 else if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 3977 sym = rtld_resolve_ifunc(defobj, def); 3978 else if (ELF_ST_TYPE(def->st_info) == STT_TLS) { 3979 ti.ti_module = defobj->tlsindex; 3980 ti.ti_offset = def->st_value; 3981 sym = __tls_get_addr(&ti); 3982 } else 3983 sym = defobj->relocbase + def->st_value; 3984 LD_UTRACE(UTRACE_DLSYM_STOP, handle, sym, 0, 0, name); 3985 return (sym); 3986 } 3987 3988 _rtld_error("Undefined symbol \"%s%s%s\"", name, ve != NULL ? "@" : "", 3989 ve != NULL ? ve->name : ""); 3990 lock_release(rtld_bind_lock, &lockstate); 3991 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 3992 return (NULL); 3993 } 3994 3995 void * 3996 dlsym(void *handle, const char *name) 3997 { 3998 return (do_dlsym(handle, name, __builtin_return_address(0), NULL, 3999 SYMLOOK_DLSYM)); 4000 } 4001 4002 dlfunc_t 4003 dlfunc(void *handle, const char *name) 4004 { 4005 union { 4006 void *d; 4007 dlfunc_t f; 4008 } rv; 4009 4010 rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL, 4011 SYMLOOK_DLSYM); 4012 return (rv.f); 4013 } 4014 4015 void * 4016 dlvsym(void *handle, const char *name, const char *version) 4017 { 4018 Ver_Entry ventry; 4019 4020 ventry.name = version; 4021 ventry.file = NULL; 4022 ventry.hash = elf_hash(version); 4023 ventry.flags= 0; 4024 return (do_dlsym(handle, name, __builtin_return_address(0), &ventry, 4025 SYMLOOK_DLSYM)); 4026 } 4027 4028 int 4029 _rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info) 4030 { 4031 const Obj_Entry *obj; 4032 RtldLockState lockstate; 4033 4034 rlock_acquire(rtld_bind_lock, &lockstate); 4035 obj = obj_from_addr(addr); 4036 if (obj == NULL) { 4037 _rtld_error("No shared object contains address"); 4038 lock_release(rtld_bind_lock, &lockstate); 4039 return (0); 4040 } 4041 rtld_fill_dl_phdr_info(obj, phdr_info); 4042 lock_release(rtld_bind_lock, &lockstate); 4043 return (1); 4044 } 4045 4046 int 4047 dladdr(const void *addr, Dl_info *info) 4048 { 4049 const Obj_Entry *obj; 4050 const Elf_Sym *def; 4051 void *symbol_addr; 4052 unsigned long symoffset; 4053 RtldLockState lockstate; 4054 4055 rlock_acquire(rtld_bind_lock, &lockstate); 4056 obj = obj_from_addr(addr); 4057 if (obj == NULL) { 4058 _rtld_error("No shared object contains address"); 4059 lock_release(rtld_bind_lock, &lockstate); 4060 return (0); 4061 } 4062 info->dli_fname = obj->path; 4063 info->dli_fbase = obj->mapbase; 4064 info->dli_saddr = (void *)0; 4065 info->dli_sname = NULL; 4066 4067 /* 4068 * Walk the symbol list looking for the symbol whose address is 4069 * closest to the address sent in. 4070 */ 4071 for (symoffset = 0; symoffset < obj->dynsymcount; symoffset++) { 4072 def = obj->symtab + symoffset; 4073 4074 /* 4075 * For skip the symbol if st_shndx is either SHN_UNDEF or 4076 * SHN_COMMON. 4077 */ 4078 if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON) 4079 continue; 4080 4081 /* 4082 * If the symbol is greater than the specified address, or if it 4083 * is further away from addr than the current nearest symbol, 4084 * then reject it. 4085 */ 4086 symbol_addr = obj->relocbase + def->st_value; 4087 if (symbol_addr > addr || symbol_addr < info->dli_saddr) 4088 continue; 4089 4090 /* Update our idea of the nearest symbol. */ 4091 info->dli_sname = obj->strtab + def->st_name; 4092 info->dli_saddr = symbol_addr; 4093 4094 /* Exact match? */ 4095 if (info->dli_saddr == addr) 4096 break; 4097 } 4098 lock_release(rtld_bind_lock, &lockstate); 4099 return (1); 4100 } 4101 4102 int 4103 dlinfo(void *handle, int request, void *p) 4104 { 4105 const Obj_Entry *obj; 4106 RtldLockState lockstate; 4107 int error; 4108 4109 rlock_acquire(rtld_bind_lock, &lockstate); 4110 4111 if (handle == NULL || handle == RTLD_SELF) { 4112 void *retaddr; 4113 4114 retaddr = __builtin_return_address(0); /* __GNUC__ only */ 4115 if ((obj = obj_from_addr(retaddr)) == NULL) 4116 _rtld_error("Cannot determine caller's shared object"); 4117 } else 4118 obj = dlcheck(handle); 4119 4120 if (obj == NULL) { 4121 lock_release(rtld_bind_lock, &lockstate); 4122 return (-1); 4123 } 4124 4125 error = 0; 4126 switch (request) { 4127 case RTLD_DI_LINKMAP: 4128 *((struct link_map const **)p) = &obj->linkmap; 4129 break; 4130 case RTLD_DI_ORIGIN: 4131 error = rtld_dirname(obj->path, p); 4132 break; 4133 4134 case RTLD_DI_SERINFOSIZE: 4135 case RTLD_DI_SERINFO: 4136 error = do_search_info(obj, request, (struct dl_serinfo *)p); 4137 break; 4138 4139 default: 4140 _rtld_error("Invalid request %d passed to dlinfo()", request); 4141 error = -1; 4142 } 4143 4144 lock_release(rtld_bind_lock, &lockstate); 4145 4146 return (error); 4147 } 4148 4149 static void 4150 rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info) 4151 { 4152 uintptr_t **dtvp; 4153 4154 phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase; 4155 phdr_info->dlpi_name = obj->path; 4156 phdr_info->dlpi_phdr = obj->phdr; 4157 phdr_info->dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]); 4158 phdr_info->dlpi_tls_modid = obj->tlsindex; 4159 dtvp = &_tcb_get()->tcb_dtv; 4160 phdr_info->dlpi_tls_data = (char *)tls_get_addr_slow(dtvp, 4161 obj->tlsindex, 0, true) + TLS_DTV_OFFSET; 4162 phdr_info->dlpi_adds = obj_loads; 4163 phdr_info->dlpi_subs = obj_loads - obj_count; 4164 } 4165 4166 int 4167 dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param) 4168 { 4169 struct dl_phdr_info phdr_info; 4170 Obj_Entry *obj, marker; 4171 RtldLockState bind_lockstate, phdr_lockstate; 4172 int error; 4173 4174 init_marker(&marker); 4175 error = 0; 4176 4177 wlock_acquire(rtld_phdr_lock, &phdr_lockstate); 4178 wlock_acquire(rtld_bind_lock, &bind_lockstate); 4179 for (obj = globallist_curr(TAILQ_FIRST(&obj_list)); obj != NULL;) { 4180 TAILQ_INSERT_AFTER(&obj_list, obj, &marker, next); 4181 rtld_fill_dl_phdr_info(obj, &phdr_info); 4182 hold_object(obj); 4183 lock_release(rtld_bind_lock, &bind_lockstate); 4184 4185 error = callback(&phdr_info, sizeof phdr_info, param); 4186 4187 wlock_acquire(rtld_bind_lock, &bind_lockstate); 4188 unhold_object(obj); 4189 obj = globallist_next(&marker); 4190 TAILQ_REMOVE(&obj_list, &marker, next); 4191 if (error != 0) { 4192 lock_release(rtld_bind_lock, &bind_lockstate); 4193 lock_release(rtld_phdr_lock, &phdr_lockstate); 4194 return (error); 4195 } 4196 } 4197 4198 if (error == 0) { 4199 rtld_fill_dl_phdr_info(&obj_rtld, &phdr_info); 4200 lock_release(rtld_bind_lock, &bind_lockstate); 4201 error = callback(&phdr_info, sizeof(phdr_info), param); 4202 } 4203 lock_release(rtld_phdr_lock, &phdr_lockstate); 4204 return (error); 4205 } 4206 4207 static void * 4208 fill_search_info(const char *dir, size_t dirlen, void *param) 4209 { 4210 struct fill_search_info_args *arg; 4211 4212 arg = param; 4213 4214 if (arg->request == RTLD_DI_SERINFOSIZE) { 4215 arg->serinfo->dls_cnt ++; 4216 arg->serinfo->dls_size += sizeof(struct dl_serpath) + dirlen + 1; 4217 } else { 4218 struct dl_serpath *s_entry; 4219 4220 s_entry = arg->serpath; 4221 s_entry->dls_name = arg->strspace; 4222 s_entry->dls_flags = arg->flags; 4223 4224 strncpy(arg->strspace, dir, dirlen); 4225 arg->strspace[dirlen] = '\0'; 4226 4227 arg->strspace += dirlen + 1; 4228 arg->serpath++; 4229 } 4230 4231 return (NULL); 4232 } 4233 4234 static int 4235 do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info) 4236 { 4237 struct dl_serinfo _info; 4238 struct fill_search_info_args args; 4239 4240 args.request = RTLD_DI_SERINFOSIZE; 4241 args.serinfo = &_info; 4242 4243 _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 4244 _info.dls_cnt = 0; 4245 4246 path_enumerate(obj->rpath, fill_search_info, NULL, &args); 4247 path_enumerate(ld_library_path, fill_search_info, NULL, &args); 4248 path_enumerate(obj->runpath, fill_search_info, NULL, &args); 4249 path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, &args); 4250 if (!obj->z_nodeflib) 4251 path_enumerate(ld_standard_library_path, fill_search_info, NULL, &args); 4252 4253 4254 if (request == RTLD_DI_SERINFOSIZE) { 4255 info->dls_size = _info.dls_size; 4256 info->dls_cnt = _info.dls_cnt; 4257 return (0); 4258 } 4259 4260 if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) { 4261 _rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()"); 4262 return (-1); 4263 } 4264 4265 args.request = RTLD_DI_SERINFO; 4266 args.serinfo = info; 4267 args.serpath = &info->dls_serpath[0]; 4268 args.strspace = (char *)&info->dls_serpath[_info.dls_cnt]; 4269 4270 args.flags = LA_SER_RUNPATH; 4271 if (path_enumerate(obj->rpath, fill_search_info, NULL, &args) != NULL) 4272 return (-1); 4273 4274 args.flags = LA_SER_LIBPATH; 4275 if (path_enumerate(ld_library_path, fill_search_info, NULL, &args) != NULL) 4276 return (-1); 4277 4278 args.flags = LA_SER_RUNPATH; 4279 if (path_enumerate(obj->runpath, fill_search_info, NULL, &args) != NULL) 4280 return (-1); 4281 4282 args.flags = LA_SER_CONFIG; 4283 if (path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, &args) 4284 != NULL) 4285 return (-1); 4286 4287 args.flags = LA_SER_DEFAULT; 4288 if (!obj->z_nodeflib && path_enumerate(ld_standard_library_path, 4289 fill_search_info, NULL, &args) != NULL) 4290 return (-1); 4291 return (0); 4292 } 4293 4294 static int 4295 rtld_dirname(const char *path, char *bname) 4296 { 4297 const char *endp; 4298 4299 /* Empty or NULL string gets treated as "." */ 4300 if (path == NULL || *path == '\0') { 4301 bname[0] = '.'; 4302 bname[1] = '\0'; 4303 return (0); 4304 } 4305 4306 /* Strip trailing slashes */ 4307 endp = path + strlen(path) - 1; 4308 while (endp > path && *endp == '/') 4309 endp--; 4310 4311 /* Find the start of the dir */ 4312 while (endp > path && *endp != '/') 4313 endp--; 4314 4315 /* Either the dir is "/" or there are no slashes */ 4316 if (endp == path) { 4317 bname[0] = *endp == '/' ? '/' : '.'; 4318 bname[1] = '\0'; 4319 return (0); 4320 } else { 4321 do { 4322 endp--; 4323 } while (endp > path && *endp == '/'); 4324 } 4325 4326 if (endp - path + 2 > PATH_MAX) 4327 { 4328 _rtld_error("Filename is too long: %s", path); 4329 return(-1); 4330 } 4331 4332 strncpy(bname, path, endp - path + 1); 4333 bname[endp - path + 1] = '\0'; 4334 return (0); 4335 } 4336 4337 static int 4338 rtld_dirname_abs(const char *path, char *base) 4339 { 4340 char *last; 4341 4342 if (realpath(path, base) == NULL) { 4343 _rtld_error("realpath \"%s\" failed (%s)", path, 4344 rtld_strerror(errno)); 4345 return (-1); 4346 } 4347 dbg("%s -> %s", path, base); 4348 last = strrchr(base, '/'); 4349 if (last == NULL) { 4350 _rtld_error("non-abs result from realpath \"%s\"", path); 4351 return (-1); 4352 } 4353 if (last != base) 4354 *last = '\0'; 4355 return (0); 4356 } 4357 4358 static void 4359 linkmap_add(Obj_Entry *obj) 4360 { 4361 struct link_map *l, *prev; 4362 4363 l = &obj->linkmap; 4364 l->l_name = obj->path; 4365 l->l_base = obj->mapbase; 4366 l->l_ld = obj->dynamic; 4367 l->l_addr = obj->relocbase; 4368 4369 if (r_debug.r_map == NULL) { 4370 r_debug.r_map = l; 4371 return; 4372 } 4373 4374 /* 4375 * Scan to the end of the list, but not past the entry for the 4376 * dynamic linker, which we want to keep at the very end. 4377 */ 4378 for (prev = r_debug.r_map; 4379 prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap; 4380 prev = prev->l_next) 4381 ; 4382 4383 /* Link in the new entry. */ 4384 l->l_prev = prev; 4385 l->l_next = prev->l_next; 4386 if (l->l_next != NULL) 4387 l->l_next->l_prev = l; 4388 prev->l_next = l; 4389 } 4390 4391 static void 4392 linkmap_delete(Obj_Entry *obj) 4393 { 4394 struct link_map *l; 4395 4396 l = &obj->linkmap; 4397 if (l->l_prev == NULL) { 4398 if ((r_debug.r_map = l->l_next) != NULL) 4399 l->l_next->l_prev = NULL; 4400 return; 4401 } 4402 4403 if ((l->l_prev->l_next = l->l_next) != NULL) 4404 l->l_next->l_prev = l->l_prev; 4405 } 4406 4407 /* 4408 * Function for the debugger to set a breakpoint on to gain control. 4409 * 4410 * The two parameters allow the debugger to easily find and determine 4411 * what the runtime loader is doing and to whom it is doing it. 4412 * 4413 * When the loadhook trap is hit (r_debug_state, set at program 4414 * initialization), the arguments can be found on the stack: 4415 * 4416 * +8 struct link_map *m 4417 * +4 struct r_debug *rd 4418 * +0 RetAddr 4419 */ 4420 void 4421 r_debug_state(struct r_debug* rd __unused, struct link_map *m __unused) 4422 { 4423 /* 4424 * The following is a hack to force the compiler to emit calls to 4425 * this function, even when optimizing. If the function is empty, 4426 * the compiler is not obliged to emit any code for calls to it, 4427 * even when marked __noinline. However, gdb depends on those 4428 * calls being made. 4429 */ 4430 __compiler_membar(); 4431 } 4432 4433 /* 4434 * A function called after init routines have completed. This can be used to 4435 * break before a program's entry routine is called, and can be used when 4436 * main is not available in the symbol table. 4437 */ 4438 void 4439 _r_debug_postinit(struct link_map *m __unused) 4440 { 4441 4442 /* See r_debug_state(). */ 4443 __compiler_membar(); 4444 } 4445 4446 static void 4447 release_object(Obj_Entry *obj) 4448 { 4449 4450 if (obj->holdcount > 0) { 4451 obj->unholdfree = true; 4452 return; 4453 } 4454 munmap(obj->mapbase, obj->mapsize); 4455 linkmap_delete(obj); 4456 obj_free(obj); 4457 } 4458 4459 /* 4460 * Get address of the pointer variable in the main program. 4461 * Prefer non-weak symbol over the weak one. 4462 */ 4463 static const void ** 4464 get_program_var_addr(const char *name, RtldLockState *lockstate) 4465 { 4466 SymLook req; 4467 DoneList donelist; 4468 4469 symlook_init(&req, name); 4470 req.lockstate = lockstate; 4471 donelist_init(&donelist); 4472 if (symlook_global(&req, &donelist) != 0) 4473 return (NULL); 4474 if (ELF_ST_TYPE(req.sym_out->st_info) == STT_FUNC) 4475 return ((const void **)make_function_pointer(req.sym_out, 4476 req.defobj_out)); 4477 else if (ELF_ST_TYPE(req.sym_out->st_info) == STT_GNU_IFUNC) 4478 return ((const void **)rtld_resolve_ifunc(req.defobj_out, req.sym_out)); 4479 else 4480 return ((const void **)(req.defobj_out->relocbase + 4481 req.sym_out->st_value)); 4482 } 4483 4484 /* 4485 * Set a pointer variable in the main program to the given value. This 4486 * is used to set key variables such as "environ" before any of the 4487 * init functions are called. 4488 */ 4489 static void 4490 set_program_var(const char *name, const void *value) 4491 { 4492 const void **addr; 4493 4494 if ((addr = get_program_var_addr(name, NULL)) != NULL) { 4495 dbg("\"%s\": *%p <-- %p", name, addr, value); 4496 *addr = value; 4497 } 4498 } 4499 4500 /* 4501 * Search the global objects, including dependencies and main object, 4502 * for the given symbol. 4503 */ 4504 static int 4505 symlook_global(SymLook *req, DoneList *donelist) 4506 { 4507 SymLook req1; 4508 const Objlist_Entry *elm; 4509 int res; 4510 4511 symlook_init_from_req(&req1, req); 4512 4513 /* Search all objects loaded at program start up. */ 4514 if (req->defobj_out == NULL || (ld_dynamic_weak && 4515 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK)) { 4516 res = symlook_list(&req1, &list_main, donelist); 4517 if (res == 0 && (!ld_dynamic_weak || req->defobj_out == NULL || 4518 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4519 req->sym_out = req1.sym_out; 4520 req->defobj_out = req1.defobj_out; 4521 assert(req->defobj_out != NULL); 4522 } 4523 } 4524 4525 /* Search all DAGs whose roots are RTLD_GLOBAL objects. */ 4526 STAILQ_FOREACH(elm, &list_global, link) { 4527 if (req->defobj_out != NULL && (!ld_dynamic_weak || 4528 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK)) 4529 break; 4530 res = symlook_list(&req1, &elm->obj->dagmembers, donelist); 4531 if (res == 0 && (req->defobj_out == NULL || 4532 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4533 req->sym_out = req1.sym_out; 4534 req->defobj_out = req1.defobj_out; 4535 assert(req->defobj_out != NULL); 4536 } 4537 } 4538 4539 return (req->sym_out != NULL ? 0 : ESRCH); 4540 } 4541 4542 /* 4543 * Given a symbol name in a referencing object, find the corresponding 4544 * definition of the symbol. Returns a pointer to the symbol, or NULL if 4545 * no definition was found. Returns a pointer to the Obj_Entry of the 4546 * defining object via the reference parameter DEFOBJ_OUT. 4547 */ 4548 static int 4549 symlook_default(SymLook *req, const Obj_Entry *refobj) 4550 { 4551 DoneList donelist; 4552 const Objlist_Entry *elm; 4553 SymLook req1; 4554 int res; 4555 4556 donelist_init(&donelist); 4557 symlook_init_from_req(&req1, req); 4558 4559 /* 4560 * Look first in the referencing object if linked symbolically, 4561 * and similarly handle protected symbols. 4562 */ 4563 res = symlook_obj(&req1, refobj); 4564 if (res == 0 && (refobj->symbolic || 4565 ELF_ST_VISIBILITY(req1.sym_out->st_other) == STV_PROTECTED)) { 4566 req->sym_out = req1.sym_out; 4567 req->defobj_out = req1.defobj_out; 4568 assert(req->defobj_out != NULL); 4569 } 4570 if (refobj->symbolic || req->defobj_out != NULL) 4571 donelist_check(&donelist, refobj); 4572 4573 symlook_global(req, &donelist); 4574 4575 /* Search all dlopened DAGs containing the referencing object. */ 4576 STAILQ_FOREACH(elm, &refobj->dldags, link) { 4577 if (req->sym_out != NULL && (!ld_dynamic_weak || 4578 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK)) 4579 break; 4580 res = symlook_list(&req1, &elm->obj->dagmembers, &donelist); 4581 if (res == 0 && (req->sym_out == NULL || 4582 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4583 req->sym_out = req1.sym_out; 4584 req->defobj_out = req1.defobj_out; 4585 assert(req->defobj_out != NULL); 4586 } 4587 } 4588 4589 /* 4590 * Search the dynamic linker itself, and possibly resolve the 4591 * symbol from there. This is how the application links to 4592 * dynamic linker services such as dlopen. 4593 */ 4594 if (req->sym_out == NULL || 4595 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 4596 res = symlook_obj(&req1, &obj_rtld); 4597 if (res == 0) { 4598 req->sym_out = req1.sym_out; 4599 req->defobj_out = req1.defobj_out; 4600 assert(req->defobj_out != NULL); 4601 } 4602 } 4603 4604 return (req->sym_out != NULL ? 0 : ESRCH); 4605 } 4606 4607 static int 4608 symlook_list(SymLook *req, const Objlist *objlist, DoneList *dlp) 4609 { 4610 const Elf_Sym *def; 4611 const Obj_Entry *defobj; 4612 const Objlist_Entry *elm; 4613 SymLook req1; 4614 int res; 4615 4616 def = NULL; 4617 defobj = NULL; 4618 STAILQ_FOREACH(elm, objlist, link) { 4619 if (donelist_check(dlp, elm->obj)) 4620 continue; 4621 symlook_init_from_req(&req1, req); 4622 if ((res = symlook_obj(&req1, elm->obj)) == 0) { 4623 if (def == NULL || (ld_dynamic_weak && 4624 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4625 def = req1.sym_out; 4626 defobj = req1.defobj_out; 4627 if (!ld_dynamic_weak || ELF_ST_BIND(def->st_info) != STB_WEAK) 4628 break; 4629 } 4630 } 4631 } 4632 if (def != NULL) { 4633 req->sym_out = def; 4634 req->defobj_out = defobj; 4635 return (0); 4636 } 4637 return (ESRCH); 4638 } 4639 4640 /* 4641 * Search the chain of DAGS cointed to by the given Needed_Entry 4642 * for a symbol of the given name. Each DAG is scanned completely 4643 * before advancing to the next one. Returns a pointer to the symbol, 4644 * or NULL if no definition was found. 4645 */ 4646 static int 4647 symlook_needed(SymLook *req, const Needed_Entry *needed, DoneList *dlp) 4648 { 4649 const Elf_Sym *def; 4650 const Needed_Entry *n; 4651 const Obj_Entry *defobj; 4652 SymLook req1; 4653 int res; 4654 4655 def = NULL; 4656 defobj = NULL; 4657 symlook_init_from_req(&req1, req); 4658 for (n = needed; n != NULL; n = n->next) { 4659 if (n->obj == NULL || 4660 (res = symlook_list(&req1, &n->obj->dagmembers, dlp)) != 0) 4661 continue; 4662 if (def == NULL || (ld_dynamic_weak && 4663 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4664 def = req1.sym_out; 4665 defobj = req1.defobj_out; 4666 if (!ld_dynamic_weak || ELF_ST_BIND(def->st_info) != STB_WEAK) 4667 break; 4668 } 4669 } 4670 if (def != NULL) { 4671 req->sym_out = def; 4672 req->defobj_out = defobj; 4673 return (0); 4674 } 4675 return (ESRCH); 4676 } 4677 4678 /* 4679 * Search the symbol table of a single shared object for a symbol of 4680 * the given name and version, if requested. Returns a pointer to the 4681 * symbol, or NULL if no definition was found. If the object is 4682 * filter, return filtered symbol from filtee. 4683 * 4684 * The symbol's hash value is passed in for efficiency reasons; that 4685 * eliminates many recomputations of the hash value. 4686 */ 4687 int 4688 symlook_obj(SymLook *req, const Obj_Entry *obj) 4689 { 4690 DoneList donelist; 4691 SymLook req1; 4692 int flags, res, mres; 4693 4694 /* 4695 * If there is at least one valid hash at this point, we prefer to 4696 * use the faster GNU version if available. 4697 */ 4698 if (obj->valid_hash_gnu) 4699 mres = symlook_obj1_gnu(req, obj); 4700 else if (obj->valid_hash_sysv) 4701 mres = symlook_obj1_sysv(req, obj); 4702 else 4703 return (EINVAL); 4704 4705 if (mres == 0) { 4706 if (obj->needed_filtees != NULL) { 4707 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; 4708 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 4709 donelist_init(&donelist); 4710 symlook_init_from_req(&req1, req); 4711 res = symlook_needed(&req1, obj->needed_filtees, &donelist); 4712 if (res == 0) { 4713 req->sym_out = req1.sym_out; 4714 req->defobj_out = req1.defobj_out; 4715 } 4716 return (res); 4717 } 4718 if (obj->needed_aux_filtees != NULL) { 4719 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; 4720 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 4721 donelist_init(&donelist); 4722 symlook_init_from_req(&req1, req); 4723 res = symlook_needed(&req1, obj->needed_aux_filtees, &donelist); 4724 if (res == 0) { 4725 req->sym_out = req1.sym_out; 4726 req->defobj_out = req1.defobj_out; 4727 return (res); 4728 } 4729 } 4730 } 4731 return (mres); 4732 } 4733 4734 /* Symbol match routine common to both hash functions */ 4735 static bool 4736 matched_symbol(SymLook *req, const Obj_Entry *obj, Sym_Match_Result *result, 4737 const unsigned long symnum) 4738 { 4739 Elf_Versym verndx; 4740 const Elf_Sym *symp; 4741 const char *strp; 4742 4743 symp = obj->symtab + symnum; 4744 strp = obj->strtab + symp->st_name; 4745 4746 switch (ELF_ST_TYPE(symp->st_info)) { 4747 case STT_FUNC: 4748 case STT_NOTYPE: 4749 case STT_OBJECT: 4750 case STT_COMMON: 4751 case STT_GNU_IFUNC: 4752 if (symp->st_value == 0) 4753 return (false); 4754 /* fallthrough */ 4755 case STT_TLS: 4756 if (symp->st_shndx != SHN_UNDEF) 4757 break; 4758 else if (((req->flags & SYMLOOK_IN_PLT) == 0) && 4759 (ELF_ST_TYPE(symp->st_info) == STT_FUNC)) 4760 break; 4761 /* fallthrough */ 4762 default: 4763 return (false); 4764 } 4765 if (req->name[0] != strp[0] || strcmp(req->name, strp) != 0) 4766 return (false); 4767 4768 if (req->ventry == NULL) { 4769 if (obj->versyms != NULL) { 4770 verndx = VER_NDX(obj->versyms[symnum]); 4771 if (verndx > obj->vernum) { 4772 _rtld_error( 4773 "%s: symbol %s references wrong version %d", 4774 obj->path, obj->strtab + symnum, verndx); 4775 return (false); 4776 } 4777 /* 4778 * If we are not called from dlsym (i.e. this 4779 * is a normal relocation from unversioned 4780 * binary), accept the symbol immediately if 4781 * it happens to have first version after this 4782 * shared object became versioned. Otherwise, 4783 * if symbol is versioned and not hidden, 4784 * remember it. If it is the only symbol with 4785 * this name exported by the shared object, it 4786 * will be returned as a match by the calling 4787 * function. If symbol is global (verndx < 2) 4788 * accept it unconditionally. 4789 */ 4790 if ((req->flags & SYMLOOK_DLSYM) == 0 && 4791 verndx == VER_NDX_GIVEN) { 4792 result->sym_out = symp; 4793 return (true); 4794 } 4795 else if (verndx >= VER_NDX_GIVEN) { 4796 if ((obj->versyms[symnum] & VER_NDX_HIDDEN) 4797 == 0) { 4798 if (result->vsymp == NULL) 4799 result->vsymp = symp; 4800 result->vcount++; 4801 } 4802 return (false); 4803 } 4804 } 4805 result->sym_out = symp; 4806 return (true); 4807 } 4808 if (obj->versyms == NULL) { 4809 if (object_match_name(obj, req->ventry->name)) { 4810 _rtld_error("%s: object %s should provide version %s " 4811 "for symbol %s", obj_rtld.path, obj->path, 4812 req->ventry->name, obj->strtab + symnum); 4813 return (false); 4814 } 4815 } else { 4816 verndx = VER_NDX(obj->versyms[symnum]); 4817 if (verndx > obj->vernum) { 4818 _rtld_error("%s: symbol %s references wrong version %d", 4819 obj->path, obj->strtab + symnum, verndx); 4820 return (false); 4821 } 4822 if (obj->vertab[verndx].hash != req->ventry->hash || 4823 strcmp(obj->vertab[verndx].name, req->ventry->name)) { 4824 /* 4825 * Version does not match. Look if this is a 4826 * global symbol and if it is not hidden. If 4827 * global symbol (verndx < 2) is available, 4828 * use it. Do not return symbol if we are 4829 * called by dlvsym, because dlvsym looks for 4830 * a specific version and default one is not 4831 * what dlvsym wants. 4832 */ 4833 if ((req->flags & SYMLOOK_DLSYM) || 4834 (verndx >= VER_NDX_GIVEN) || 4835 (obj->versyms[symnum] & VER_NDX_HIDDEN)) 4836 return (false); 4837 } 4838 } 4839 result->sym_out = symp; 4840 return (true); 4841 } 4842 4843 /* 4844 * Search for symbol using SysV hash function. 4845 * obj->buckets is known not to be NULL at this point; the test for this was 4846 * performed with the obj->valid_hash_sysv assignment. 4847 */ 4848 static int 4849 symlook_obj1_sysv(SymLook *req, const Obj_Entry *obj) 4850 { 4851 unsigned long symnum; 4852 Sym_Match_Result matchres; 4853 4854 matchres.sym_out = NULL; 4855 matchres.vsymp = NULL; 4856 matchres.vcount = 0; 4857 4858 for (symnum = obj->buckets[req->hash % obj->nbuckets]; 4859 symnum != STN_UNDEF; symnum = obj->chains[symnum]) { 4860 if (symnum >= obj->nchains) 4861 return (ESRCH); /* Bad object */ 4862 4863 if (matched_symbol(req, obj, &matchres, symnum)) { 4864 req->sym_out = matchres.sym_out; 4865 req->defobj_out = obj; 4866 return (0); 4867 } 4868 } 4869 if (matchres.vcount == 1) { 4870 req->sym_out = matchres.vsymp; 4871 req->defobj_out = obj; 4872 return (0); 4873 } 4874 return (ESRCH); 4875 } 4876 4877 /* Search for symbol using GNU hash function */ 4878 static int 4879 symlook_obj1_gnu(SymLook *req, const Obj_Entry *obj) 4880 { 4881 Elf_Addr bloom_word; 4882 const Elf32_Word *hashval; 4883 Elf32_Word bucket; 4884 Sym_Match_Result matchres; 4885 unsigned int h1, h2; 4886 unsigned long symnum; 4887 4888 matchres.sym_out = NULL; 4889 matchres.vsymp = NULL; 4890 matchres.vcount = 0; 4891 4892 /* Pick right bitmask word from Bloom filter array */ 4893 bloom_word = obj->bloom_gnu[(req->hash_gnu / __ELF_WORD_SIZE) & 4894 obj->maskwords_bm_gnu]; 4895 4896 /* Calculate modulus word size of gnu hash and its derivative */ 4897 h1 = req->hash_gnu & (__ELF_WORD_SIZE - 1); 4898 h2 = ((req->hash_gnu >> obj->shift2_gnu) & (__ELF_WORD_SIZE - 1)); 4899 4900 /* Filter out the "definitely not in set" queries */ 4901 if (((bloom_word >> h1) & (bloom_word >> h2) & 1) == 0) 4902 return (ESRCH); 4903 4904 /* Locate hash chain and corresponding value element*/ 4905 bucket = obj->buckets_gnu[req->hash_gnu % obj->nbuckets_gnu]; 4906 if (bucket == 0) 4907 return (ESRCH); 4908 hashval = &obj->chain_zero_gnu[bucket]; 4909 do { 4910 if (((*hashval ^ req->hash_gnu) >> 1) == 0) { 4911 symnum = hashval - obj->chain_zero_gnu; 4912 if (matched_symbol(req, obj, &matchres, symnum)) { 4913 req->sym_out = matchres.sym_out; 4914 req->defobj_out = obj; 4915 return (0); 4916 } 4917 } 4918 } while ((*hashval++ & 1) == 0); 4919 if (matchres.vcount == 1) { 4920 req->sym_out = matchres.vsymp; 4921 req->defobj_out = obj; 4922 return (0); 4923 } 4924 return (ESRCH); 4925 } 4926 4927 static void 4928 trace_calc_fmts(const char **main_local, const char **fmt1, const char **fmt2) 4929 { 4930 *main_local = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_PROGNAME); 4931 if (*main_local == NULL) 4932 *main_local = ""; 4933 4934 *fmt1 = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_FMT1); 4935 if (*fmt1 == NULL) 4936 *fmt1 = "\t%o => %p (%x)\n"; 4937 4938 *fmt2 = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_FMT2); 4939 if (*fmt2 == NULL) 4940 *fmt2 = "\t%o (%x)\n"; 4941 } 4942 4943 static void 4944 trace_print_obj(Obj_Entry *obj, const char *name, const char *path, 4945 const char *main_local, const char *fmt1, const char *fmt2) 4946 { 4947 const char *fmt; 4948 int c; 4949 4950 if (fmt1 == NULL) 4951 fmt = fmt2; 4952 else 4953 /* XXX bogus */ 4954 fmt = strncmp(name, "lib", 3) == 0 ? fmt1 : fmt2; 4955 4956 while ((c = *fmt++) != '\0') { 4957 switch (c) { 4958 default: 4959 rtld_putchar(c); 4960 continue; 4961 case '\\': 4962 switch (c = *fmt) { 4963 case '\0': 4964 continue; 4965 case 'n': 4966 rtld_putchar('\n'); 4967 break; 4968 case 't': 4969 rtld_putchar('\t'); 4970 break; 4971 } 4972 break; 4973 case '%': 4974 switch (c = *fmt) { 4975 case '\0': 4976 continue; 4977 case '%': 4978 default: 4979 rtld_putchar(c); 4980 break; 4981 case 'A': 4982 rtld_putstr(main_local); 4983 break; 4984 case 'a': 4985 rtld_putstr(obj_main->path); 4986 break; 4987 case 'o': 4988 rtld_putstr(name); 4989 break; 4990 case 'p': 4991 rtld_putstr(path); 4992 break; 4993 case 'x': 4994 rtld_printf("%p", obj != NULL ? 4995 obj->mapbase : NULL); 4996 break; 4997 } 4998 break; 4999 } 5000 ++fmt; 5001 } 5002 } 5003 5004 static void 5005 trace_loaded_objects(Obj_Entry *obj, bool show_preload) 5006 { 5007 const char *fmt1, *fmt2, *main_local; 5008 const char *name, *path; 5009 bool first_spurious, list_containers; 5010 5011 trace_calc_fmts(&main_local, &fmt1, &fmt2); 5012 list_containers = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_ALL) != NULL; 5013 5014 for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 5015 Needed_Entry *needed; 5016 5017 if (obj->marker) 5018 continue; 5019 if (list_containers && obj->needed != NULL) 5020 rtld_printf("%s:\n", obj->path); 5021 for (needed = obj->needed; needed; needed = needed->next) { 5022 if (needed->obj != NULL) { 5023 if (needed->obj->traced && !list_containers) 5024 continue; 5025 needed->obj->traced = true; 5026 path = needed->obj->path; 5027 } else 5028 path = "not found"; 5029 5030 name = obj->strtab + needed->name; 5031 trace_print_obj(needed->obj, name, path, main_local, 5032 fmt1, fmt2); 5033 } 5034 } 5035 5036 if (show_preload) { 5037 if (ld_get_env_var(LD_TRACE_LOADED_OBJECTS_FMT2) == NULL) 5038 fmt2 = "\t%p (%x)\n"; 5039 first_spurious = true; 5040 5041 TAILQ_FOREACH(obj, &obj_list, next) { 5042 if (obj->marker || obj == obj_main || obj->traced) 5043 continue; 5044 5045 if (list_containers && first_spurious) { 5046 rtld_printf("[preloaded]\n"); 5047 first_spurious = false; 5048 } 5049 5050 Name_Entry *fname = STAILQ_FIRST(&obj->names); 5051 name = fname == NULL ? "<unknown>" : fname->name; 5052 trace_print_obj(obj, name, obj->path, main_local, 5053 NULL, fmt2); 5054 } 5055 } 5056 } 5057 5058 /* 5059 * Unload a dlopened object and its dependencies from memory and from 5060 * our data structures. It is assumed that the DAG rooted in the 5061 * object has already been unreferenced, and that the object has a 5062 * reference count of 0. 5063 */ 5064 static void 5065 unload_object(Obj_Entry *root, RtldLockState *lockstate) 5066 { 5067 Obj_Entry marker, *obj, *next; 5068 5069 assert(root->refcount == 0); 5070 5071 /* 5072 * Pass over the DAG removing unreferenced objects from 5073 * appropriate lists. 5074 */ 5075 unlink_object(root); 5076 5077 /* Unmap all objects that are no longer referenced. */ 5078 for (obj = TAILQ_FIRST(&obj_list); obj != NULL; obj = next) { 5079 next = TAILQ_NEXT(obj, next); 5080 if (obj->marker || obj->refcount != 0) 5081 continue; 5082 LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase, 5083 obj->mapsize, 0, obj->path); 5084 dbg("unloading \"%s\"", obj->path); 5085 /* 5086 * Unlink the object now to prevent new references from 5087 * being acquired while the bind lock is dropped in 5088 * recursive dlclose() invocations. 5089 */ 5090 TAILQ_REMOVE(&obj_list, obj, next); 5091 obj_count--; 5092 5093 if (obj->filtees_loaded) { 5094 if (next != NULL) { 5095 init_marker(&marker); 5096 TAILQ_INSERT_BEFORE(next, &marker, next); 5097 unload_filtees(obj, lockstate); 5098 next = TAILQ_NEXT(&marker, next); 5099 TAILQ_REMOVE(&obj_list, &marker, next); 5100 } else 5101 unload_filtees(obj, lockstate); 5102 } 5103 release_object(obj); 5104 } 5105 } 5106 5107 static void 5108 unlink_object(Obj_Entry *root) 5109 { 5110 Objlist_Entry *elm; 5111 5112 if (root->refcount == 0) { 5113 /* Remove the object from the RTLD_GLOBAL list. */ 5114 objlist_remove(&list_global, root); 5115 5116 /* Remove the object from all objects' DAG lists. */ 5117 STAILQ_FOREACH(elm, &root->dagmembers, link) { 5118 objlist_remove(&elm->obj->dldags, root); 5119 if (elm->obj != root) 5120 unlink_object(elm->obj); 5121 } 5122 } 5123 } 5124 5125 static void 5126 ref_dag(Obj_Entry *root) 5127 { 5128 Objlist_Entry *elm; 5129 5130 assert(root->dag_inited); 5131 STAILQ_FOREACH(elm, &root->dagmembers, link) 5132 elm->obj->refcount++; 5133 } 5134 5135 static void 5136 unref_dag(Obj_Entry *root) 5137 { 5138 Objlist_Entry *elm; 5139 5140 assert(root->dag_inited); 5141 STAILQ_FOREACH(elm, &root->dagmembers, link) 5142 elm->obj->refcount--; 5143 } 5144 5145 /* 5146 * Common code for MD __tls_get_addr(). 5147 */ 5148 static void * 5149 tls_get_addr_slow(Elf_Addr **dtvp, int index, size_t offset, bool locked) 5150 { 5151 Elf_Addr *newdtv, *dtv; 5152 RtldLockState lockstate; 5153 int to_copy; 5154 5155 dtv = *dtvp; 5156 /* Check dtv generation in case new modules have arrived */ 5157 if (dtv[0] != tls_dtv_generation) { 5158 if (!locked) 5159 wlock_acquire(rtld_bind_lock, &lockstate); 5160 newdtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 5161 to_copy = dtv[1]; 5162 if (to_copy > tls_max_index) 5163 to_copy = tls_max_index; 5164 memcpy(&newdtv[2], &dtv[2], to_copy * sizeof(Elf_Addr)); 5165 newdtv[0] = tls_dtv_generation; 5166 newdtv[1] = tls_max_index; 5167 free(dtv); 5168 if (!locked) 5169 lock_release(rtld_bind_lock, &lockstate); 5170 dtv = *dtvp = newdtv; 5171 } 5172 5173 /* Dynamically allocate module TLS if necessary */ 5174 if (dtv[index + 1] == 0) { 5175 /* Signal safe, wlock will block out signals. */ 5176 if (!locked) 5177 wlock_acquire(rtld_bind_lock, &lockstate); 5178 if (!dtv[index + 1]) 5179 dtv[index + 1] = (Elf_Addr)allocate_module_tls(index); 5180 if (!locked) 5181 lock_release(rtld_bind_lock, &lockstate); 5182 } 5183 return ((void *)(dtv[index + 1] + offset)); 5184 } 5185 5186 void * 5187 tls_get_addr_common(uintptr_t **dtvp, int index, size_t offset) 5188 { 5189 uintptr_t *dtv; 5190 5191 dtv = *dtvp; 5192 /* Check dtv generation in case new modules have arrived */ 5193 if (__predict_true(dtv[0] == tls_dtv_generation && 5194 dtv[index + 1] != 0)) 5195 return ((void *)(dtv[index + 1] + offset)); 5196 return (tls_get_addr_slow(dtvp, index, offset, false)); 5197 } 5198 5199 #ifdef TLS_VARIANT_I 5200 5201 /* 5202 * Return pointer to allocated TLS block 5203 */ 5204 static void * 5205 get_tls_block_ptr(void *tcb, size_t tcbsize) 5206 { 5207 size_t extra_size, post_size, pre_size, tls_block_size; 5208 size_t tls_init_align; 5209 5210 tls_init_align = MAX(obj_main->tlsalign, 1); 5211 5212 /* Compute fragments sizes. */ 5213 extra_size = tcbsize - TLS_TCB_SIZE; 5214 post_size = calculate_tls_post_size(tls_init_align); 5215 tls_block_size = tcbsize + post_size; 5216 pre_size = roundup2(tls_block_size, tls_init_align) - tls_block_size; 5217 5218 return ((char *)tcb - pre_size - extra_size); 5219 } 5220 5221 /* 5222 * Allocate Static TLS using the Variant I method. 5223 * 5224 * For details on the layout, see lib/libc/gen/tls.c. 5225 * 5226 * NB: rtld's tls_static_space variable includes TLS_TCB_SIZE and post_size as 5227 * it is based on tls_last_offset, and TLS offsets here are really TCB 5228 * offsets, whereas libc's tls_static_space is just the executable's static 5229 * TLS segment. 5230 */ 5231 void * 5232 allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign) 5233 { 5234 Obj_Entry *obj; 5235 char *tls_block; 5236 Elf_Addr *dtv, **tcb; 5237 Elf_Addr addr; 5238 Elf_Addr i; 5239 size_t extra_size, maxalign, post_size, pre_size, tls_block_size; 5240 size_t tls_init_align, tls_init_offset; 5241 5242 if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE) 5243 return (oldtcb); 5244 5245 assert(tcbsize >= TLS_TCB_SIZE); 5246 maxalign = MAX(tcbalign, tls_static_max_align); 5247 tls_init_align = MAX(obj_main->tlsalign, 1); 5248 5249 /* Compute fragmets sizes. */ 5250 extra_size = tcbsize - TLS_TCB_SIZE; 5251 post_size = calculate_tls_post_size(tls_init_align); 5252 tls_block_size = tcbsize + post_size; 5253 pre_size = roundup2(tls_block_size, tls_init_align) - tls_block_size; 5254 tls_block_size += pre_size + tls_static_space - TLS_TCB_SIZE - post_size; 5255 5256 /* Allocate whole TLS block */ 5257 tls_block = xmalloc_aligned(tls_block_size, maxalign, 0); 5258 tcb = (Elf_Addr **)(tls_block + pre_size + extra_size); 5259 5260 if (oldtcb != NULL) { 5261 memcpy(tls_block, get_tls_block_ptr(oldtcb, tcbsize), 5262 tls_static_space); 5263 free(get_tls_block_ptr(oldtcb, tcbsize)); 5264 5265 /* Adjust the DTV. */ 5266 dtv = tcb[0]; 5267 for (i = 0; i < dtv[1]; i++) { 5268 if (dtv[i+2] >= (Elf_Addr)oldtcb && 5269 dtv[i+2] < (Elf_Addr)oldtcb + tls_static_space) { 5270 dtv[i+2] = dtv[i+2] - (Elf_Addr)oldtcb + (Elf_Addr)tcb; 5271 } 5272 } 5273 } else { 5274 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 5275 tcb[0] = dtv; 5276 dtv[0] = tls_dtv_generation; 5277 dtv[1] = tls_max_index; 5278 5279 for (obj = globallist_curr(objs); obj != NULL; 5280 obj = globallist_next(obj)) { 5281 if (obj->tlsoffset == 0) 5282 continue; 5283 tls_init_offset = obj->tlspoffset & (obj->tlsalign - 1); 5284 addr = (Elf_Addr)tcb + obj->tlsoffset; 5285 if (tls_init_offset > 0) 5286 memset((void *)addr, 0, tls_init_offset); 5287 if (obj->tlsinitsize > 0) { 5288 memcpy((void *)(addr + tls_init_offset), obj->tlsinit, 5289 obj->tlsinitsize); 5290 } 5291 if (obj->tlssize > obj->tlsinitsize) { 5292 memset((void *)(addr + tls_init_offset + obj->tlsinitsize), 5293 0, obj->tlssize - obj->tlsinitsize - tls_init_offset); 5294 } 5295 dtv[obj->tlsindex + 1] = addr; 5296 } 5297 } 5298 5299 return (tcb); 5300 } 5301 5302 void 5303 free_tls(void *tcb, size_t tcbsize, size_t tcbalign __unused) 5304 { 5305 Elf_Addr *dtv; 5306 Elf_Addr tlsstart, tlsend; 5307 size_t post_size; 5308 size_t dtvsize, i, tls_init_align __unused; 5309 5310 assert(tcbsize >= TLS_TCB_SIZE); 5311 tls_init_align = MAX(obj_main->tlsalign, 1); 5312 5313 /* Compute fragments sizes. */ 5314 post_size = calculate_tls_post_size(tls_init_align); 5315 5316 tlsstart = (Elf_Addr)tcb + TLS_TCB_SIZE + post_size; 5317 tlsend = (Elf_Addr)tcb + tls_static_space; 5318 5319 dtv = *(Elf_Addr **)tcb; 5320 dtvsize = dtv[1]; 5321 for (i = 0; i < dtvsize; i++) { 5322 if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] >= tlsend)) { 5323 free((void*)dtv[i+2]); 5324 } 5325 } 5326 free(dtv); 5327 free(get_tls_block_ptr(tcb, tcbsize)); 5328 } 5329 5330 #endif /* TLS_VARIANT_I */ 5331 5332 #ifdef TLS_VARIANT_II 5333 5334 /* 5335 * Allocate Static TLS using the Variant II method. 5336 */ 5337 void * 5338 allocate_tls(Obj_Entry *objs, void *oldtls, size_t tcbsize, size_t tcbalign) 5339 { 5340 Obj_Entry *obj; 5341 size_t size, ralign; 5342 char *tls; 5343 Elf_Addr *dtv, *olddtv; 5344 Elf_Addr segbase, oldsegbase, addr; 5345 size_t i; 5346 5347 ralign = tcbalign; 5348 if (tls_static_max_align > ralign) 5349 ralign = tls_static_max_align; 5350 size = roundup(tls_static_space, ralign) + roundup(tcbsize, ralign); 5351 5352 assert(tcbsize >= 2*sizeof(Elf_Addr)); 5353 tls = xmalloc_aligned(size, ralign, 0 /* XXX */); 5354 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 5355 5356 segbase = (Elf_Addr)(tls + roundup(tls_static_space, ralign)); 5357 ((Elf_Addr *)segbase)[0] = segbase; 5358 ((Elf_Addr *)segbase)[1] = (Elf_Addr) dtv; 5359 5360 dtv[0] = tls_dtv_generation; 5361 dtv[1] = tls_max_index; 5362 5363 if (oldtls) { 5364 /* 5365 * Copy the static TLS block over whole. 5366 */ 5367 oldsegbase = (Elf_Addr) oldtls; 5368 memcpy((void *)(segbase - tls_static_space), 5369 (const void *)(oldsegbase - tls_static_space), 5370 tls_static_space); 5371 5372 /* 5373 * If any dynamic TLS blocks have been created tls_get_addr(), 5374 * move them over. 5375 */ 5376 olddtv = ((Elf_Addr **)oldsegbase)[1]; 5377 for (i = 0; i < olddtv[1]; i++) { 5378 if (olddtv[i + 2] < oldsegbase - size || 5379 olddtv[i + 2] > oldsegbase) { 5380 dtv[i + 2] = olddtv[i + 2]; 5381 olddtv[i + 2] = 0; 5382 } 5383 } 5384 5385 /* 5386 * We assume that this block was the one we created with 5387 * allocate_initial_tls(). 5388 */ 5389 free_tls(oldtls, 2 * sizeof(Elf_Addr), sizeof(Elf_Addr)); 5390 } else { 5391 for (obj = objs; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 5392 if (obj->marker || obj->tlsoffset == 0) 5393 continue; 5394 addr = segbase - obj->tlsoffset; 5395 memset((void *)(addr + obj->tlsinitsize), 5396 0, obj->tlssize - obj->tlsinitsize); 5397 if (obj->tlsinit) { 5398 memcpy((void *)addr, obj->tlsinit, obj->tlsinitsize); 5399 obj->static_tls_copied = true; 5400 } 5401 dtv[obj->tlsindex + 1] = addr; 5402 } 5403 } 5404 5405 return ((void *)segbase); 5406 } 5407 5408 void 5409 free_tls(void *tls, size_t tcbsize __unused, size_t tcbalign) 5410 { 5411 Elf_Addr* dtv; 5412 size_t size, ralign; 5413 int dtvsize, i; 5414 Elf_Addr tlsstart, tlsend; 5415 5416 /* 5417 * Figure out the size of the initial TLS block so that we can 5418 * find stuff which ___tls_get_addr() allocated dynamically. 5419 */ 5420 ralign = tcbalign; 5421 if (tls_static_max_align > ralign) 5422 ralign = tls_static_max_align; 5423 size = roundup(tls_static_space, ralign); 5424 5425 dtv = ((Elf_Addr **)tls)[1]; 5426 dtvsize = dtv[1]; 5427 tlsend = (Elf_Addr)tls; 5428 tlsstart = tlsend - size; 5429 for (i = 0; i < dtvsize; i++) { 5430 if (dtv[i + 2] != 0 && (dtv[i + 2] < tlsstart || 5431 dtv[i + 2] > tlsend)) { 5432 free((void *)dtv[i + 2]); 5433 } 5434 } 5435 5436 free((void *)tlsstart); 5437 free((void *)dtv); 5438 } 5439 5440 #endif /* TLS_VARIANT_II */ 5441 5442 /* 5443 * Allocate TLS block for module with given index. 5444 */ 5445 void * 5446 allocate_module_tls(int index) 5447 { 5448 Obj_Entry *obj; 5449 char *p; 5450 5451 TAILQ_FOREACH(obj, &obj_list, next) { 5452 if (obj->marker) 5453 continue; 5454 if (obj->tlsindex == index) 5455 break; 5456 } 5457 if (obj == NULL) { 5458 _rtld_error("Can't find module with TLS index %d", index); 5459 rtld_die(); 5460 } 5461 5462 if (obj->tls_static) { 5463 #ifdef TLS_VARIANT_I 5464 p = (char *)_tcb_get() + obj->tlsoffset + TLS_TCB_SIZE; 5465 #else 5466 p = (char *)_tcb_get() - obj->tlsoffset; 5467 #endif 5468 return (p); 5469 } 5470 5471 obj->tls_dynamic = true; 5472 5473 p = xmalloc_aligned(obj->tlssize, obj->tlsalign, obj->tlspoffset); 5474 memcpy(p, obj->tlsinit, obj->tlsinitsize); 5475 memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize); 5476 return (p); 5477 } 5478 5479 bool 5480 allocate_tls_offset(Obj_Entry *obj) 5481 { 5482 size_t off; 5483 5484 if (obj->tls_dynamic) 5485 return (false); 5486 5487 if (obj->tls_static) 5488 return (true); 5489 5490 if (obj->tlssize == 0) { 5491 obj->tls_static = true; 5492 return (true); 5493 } 5494 5495 if (tls_last_offset == 0) 5496 off = calculate_first_tls_offset(obj->tlssize, obj->tlsalign, 5497 obj->tlspoffset); 5498 else 5499 off = calculate_tls_offset(tls_last_offset, tls_last_size, 5500 obj->tlssize, obj->tlsalign, obj->tlspoffset); 5501 5502 obj->tlsoffset = off; 5503 #ifdef TLS_VARIANT_I 5504 off += obj->tlssize; 5505 #endif 5506 5507 /* 5508 * If we have already fixed the size of the static TLS block, we 5509 * must stay within that size. When allocating the static TLS, we 5510 * leave a small amount of space spare to be used for dynamically 5511 * loading modules which use static TLS. 5512 */ 5513 if (tls_static_space != 0) { 5514 if (off > tls_static_space) 5515 return (false); 5516 } else if (obj->tlsalign > tls_static_max_align) { 5517 tls_static_max_align = obj->tlsalign; 5518 } 5519 5520 tls_last_offset = off; 5521 tls_last_size = obj->tlssize; 5522 obj->tls_static = true; 5523 5524 return (true); 5525 } 5526 5527 void 5528 free_tls_offset(Obj_Entry *obj) 5529 { 5530 5531 /* 5532 * If we were the last thing to allocate out of the static TLS 5533 * block, we give our space back to the 'allocator'. This is a 5534 * simplistic workaround to allow libGL.so.1 to be loaded and 5535 * unloaded multiple times. 5536 */ 5537 size_t off = obj->tlsoffset; 5538 #ifdef TLS_VARIANT_I 5539 off += obj->tlssize; 5540 #endif 5541 if (off == tls_last_offset) { 5542 tls_last_offset -= obj->tlssize; 5543 tls_last_size = 0; 5544 } 5545 } 5546 5547 void * 5548 _rtld_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign) 5549 { 5550 void *ret; 5551 RtldLockState lockstate; 5552 5553 wlock_acquire(rtld_bind_lock, &lockstate); 5554 ret = allocate_tls(globallist_curr(TAILQ_FIRST(&obj_list)), oldtls, 5555 tcbsize, tcbalign); 5556 lock_release(rtld_bind_lock, &lockstate); 5557 return (ret); 5558 } 5559 5560 void 5561 _rtld_free_tls(void *tcb, size_t tcbsize, size_t tcbalign) 5562 { 5563 RtldLockState lockstate; 5564 5565 wlock_acquire(rtld_bind_lock, &lockstate); 5566 free_tls(tcb, tcbsize, tcbalign); 5567 lock_release(rtld_bind_lock, &lockstate); 5568 } 5569 5570 static void 5571 object_add_name(Obj_Entry *obj, const char *name) 5572 { 5573 Name_Entry *entry; 5574 size_t len; 5575 5576 len = strlen(name); 5577 entry = malloc(sizeof(Name_Entry) + len); 5578 5579 if (entry != NULL) { 5580 strcpy(entry->name, name); 5581 STAILQ_INSERT_TAIL(&obj->names, entry, link); 5582 } 5583 } 5584 5585 static int 5586 object_match_name(const Obj_Entry *obj, const char *name) 5587 { 5588 Name_Entry *entry; 5589 5590 STAILQ_FOREACH(entry, &obj->names, link) { 5591 if (strcmp(name, entry->name) == 0) 5592 return (1); 5593 } 5594 return (0); 5595 } 5596 5597 static Obj_Entry * 5598 locate_dependency(const Obj_Entry *obj, const char *name) 5599 { 5600 const Objlist_Entry *entry; 5601 const Needed_Entry *needed; 5602 5603 STAILQ_FOREACH(entry, &list_main, link) { 5604 if (object_match_name(entry->obj, name)) 5605 return (entry->obj); 5606 } 5607 5608 for (needed = obj->needed; needed != NULL; needed = needed->next) { 5609 if (strcmp(obj->strtab + needed->name, name) == 0 || 5610 (needed->obj != NULL && object_match_name(needed->obj, name))) { 5611 /* 5612 * If there is DT_NEEDED for the name we are looking for, 5613 * we are all set. Note that object might not be found if 5614 * dependency was not loaded yet, so the function can 5615 * return NULL here. This is expected and handled 5616 * properly by the caller. 5617 */ 5618 return (needed->obj); 5619 } 5620 } 5621 _rtld_error("%s: Unexpected inconsistency: dependency %s not found", 5622 obj->path, name); 5623 rtld_die(); 5624 } 5625 5626 static int 5627 check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj, 5628 const Elf_Vernaux *vna) 5629 { 5630 const Elf_Verdef *vd; 5631 const char *vername; 5632 5633 vername = refobj->strtab + vna->vna_name; 5634 vd = depobj->verdef; 5635 if (vd == NULL) { 5636 _rtld_error("%s: version %s required by %s not defined", 5637 depobj->path, vername, refobj->path); 5638 return (-1); 5639 } 5640 for (;;) { 5641 if (vd->vd_version != VER_DEF_CURRENT) { 5642 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 5643 depobj->path, vd->vd_version); 5644 return (-1); 5645 } 5646 if (vna->vna_hash == vd->vd_hash) { 5647 const Elf_Verdaux *aux = (const Elf_Verdaux *) 5648 ((const char *)vd + vd->vd_aux); 5649 if (strcmp(vername, depobj->strtab + aux->vda_name) == 0) 5650 return (0); 5651 } 5652 if (vd->vd_next == 0) 5653 break; 5654 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 5655 } 5656 if (vna->vna_flags & VER_FLG_WEAK) 5657 return (0); 5658 _rtld_error("%s: version %s required by %s not found", 5659 depobj->path, vername, refobj->path); 5660 return (-1); 5661 } 5662 5663 static int 5664 rtld_verify_object_versions(Obj_Entry *obj) 5665 { 5666 const Elf_Verneed *vn; 5667 const Elf_Verdef *vd; 5668 const Elf_Verdaux *vda; 5669 const Elf_Vernaux *vna; 5670 const Obj_Entry *depobj; 5671 int maxvernum, vernum; 5672 5673 if (obj->ver_checked) 5674 return (0); 5675 obj->ver_checked = true; 5676 5677 maxvernum = 0; 5678 /* 5679 * Walk over defined and required version records and figure out 5680 * max index used by any of them. Do very basic sanity checking 5681 * while there. 5682 */ 5683 vn = obj->verneed; 5684 while (vn != NULL) { 5685 if (vn->vn_version != VER_NEED_CURRENT) { 5686 _rtld_error("%s: Unsupported version %d of Elf_Verneed entry", 5687 obj->path, vn->vn_version); 5688 return (-1); 5689 } 5690 vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux); 5691 for (;;) { 5692 vernum = VER_NEED_IDX(vna->vna_other); 5693 if (vernum > maxvernum) 5694 maxvernum = vernum; 5695 if (vna->vna_next == 0) 5696 break; 5697 vna = (const Elf_Vernaux *)((const char *)vna + vna->vna_next); 5698 } 5699 if (vn->vn_next == 0) 5700 break; 5701 vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next); 5702 } 5703 5704 vd = obj->verdef; 5705 while (vd != NULL) { 5706 if (vd->vd_version != VER_DEF_CURRENT) { 5707 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 5708 obj->path, vd->vd_version); 5709 return (-1); 5710 } 5711 vernum = VER_DEF_IDX(vd->vd_ndx); 5712 if (vernum > maxvernum) 5713 maxvernum = vernum; 5714 if (vd->vd_next == 0) 5715 break; 5716 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 5717 } 5718 5719 if (maxvernum == 0) 5720 return (0); 5721 5722 /* 5723 * Store version information in array indexable by version index. 5724 * Verify that object version requirements are satisfied along the 5725 * way. 5726 */ 5727 obj->vernum = maxvernum + 1; 5728 obj->vertab = xcalloc(obj->vernum, sizeof(Ver_Entry)); 5729 5730 vd = obj->verdef; 5731 while (vd != NULL) { 5732 if ((vd->vd_flags & VER_FLG_BASE) == 0) { 5733 vernum = VER_DEF_IDX(vd->vd_ndx); 5734 assert(vernum <= maxvernum); 5735 vda = (const Elf_Verdaux *)((const char *)vd + vd->vd_aux); 5736 obj->vertab[vernum].hash = vd->vd_hash; 5737 obj->vertab[vernum].name = obj->strtab + vda->vda_name; 5738 obj->vertab[vernum].file = NULL; 5739 obj->vertab[vernum].flags = 0; 5740 } 5741 if (vd->vd_next == 0) 5742 break; 5743 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 5744 } 5745 5746 vn = obj->verneed; 5747 while (vn != NULL) { 5748 depobj = locate_dependency(obj, obj->strtab + vn->vn_file); 5749 if (depobj == NULL) 5750 return (-1); 5751 vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux); 5752 for (;;) { 5753 if (check_object_provided_version(obj, depobj, vna)) 5754 return (-1); 5755 vernum = VER_NEED_IDX(vna->vna_other); 5756 assert(vernum <= maxvernum); 5757 obj->vertab[vernum].hash = vna->vna_hash; 5758 obj->vertab[vernum].name = obj->strtab + vna->vna_name; 5759 obj->vertab[vernum].file = obj->strtab + vn->vn_file; 5760 obj->vertab[vernum].flags = (vna->vna_other & VER_NEED_HIDDEN) ? 5761 VER_INFO_HIDDEN : 0; 5762 if (vna->vna_next == 0) 5763 break; 5764 vna = (const Elf_Vernaux *)((const char *)vna + vna->vna_next); 5765 } 5766 if (vn->vn_next == 0) 5767 break; 5768 vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next); 5769 } 5770 return (0); 5771 } 5772 5773 static int 5774 rtld_verify_versions(const Objlist *objlist) 5775 { 5776 Objlist_Entry *entry; 5777 int rc; 5778 5779 rc = 0; 5780 STAILQ_FOREACH(entry, objlist, link) { 5781 /* 5782 * Skip dummy objects or objects that have their version requirements 5783 * already checked. 5784 */ 5785 if (entry->obj->strtab == NULL || entry->obj->vertab != NULL) 5786 continue; 5787 if (rtld_verify_object_versions(entry->obj) == -1) { 5788 rc = -1; 5789 if (ld_tracing == NULL) 5790 break; 5791 } 5792 } 5793 if (rc == 0 || ld_tracing != NULL) 5794 rc = rtld_verify_object_versions(&obj_rtld); 5795 return (rc); 5796 } 5797 5798 const Ver_Entry * 5799 fetch_ventry(const Obj_Entry *obj, unsigned long symnum) 5800 { 5801 Elf_Versym vernum; 5802 5803 if (obj->vertab) { 5804 vernum = VER_NDX(obj->versyms[symnum]); 5805 if (vernum >= obj->vernum) { 5806 _rtld_error("%s: symbol %s has wrong verneed value %d", 5807 obj->path, obj->strtab + symnum, vernum); 5808 } else if (obj->vertab[vernum].hash != 0) { 5809 return (&obj->vertab[vernum]); 5810 } 5811 } 5812 return (NULL); 5813 } 5814 5815 int 5816 _rtld_get_stack_prot(void) 5817 { 5818 5819 return (stack_prot); 5820 } 5821 5822 int 5823 _rtld_is_dlopened(void *arg) 5824 { 5825 Obj_Entry *obj; 5826 RtldLockState lockstate; 5827 int res; 5828 5829 rlock_acquire(rtld_bind_lock, &lockstate); 5830 obj = dlcheck(arg); 5831 if (obj == NULL) 5832 obj = obj_from_addr(arg); 5833 if (obj == NULL) { 5834 _rtld_error("No shared object contains address"); 5835 lock_release(rtld_bind_lock, &lockstate); 5836 return (-1); 5837 } 5838 res = obj->dlopened ? 1 : 0; 5839 lock_release(rtld_bind_lock, &lockstate); 5840 return (res); 5841 } 5842 5843 static int 5844 obj_remap_relro(Obj_Entry *obj, int prot) 5845 { 5846 5847 if (obj->relro_size > 0 && mprotect(obj->relro_page, obj->relro_size, 5848 prot) == -1) { 5849 _rtld_error("%s: Cannot set relro protection to %#x: %s", 5850 obj->path, prot, rtld_strerror(errno)); 5851 return (-1); 5852 } 5853 return (0); 5854 } 5855 5856 static int 5857 obj_disable_relro(Obj_Entry *obj) 5858 { 5859 5860 return (obj_remap_relro(obj, PROT_READ | PROT_WRITE)); 5861 } 5862 5863 static int 5864 obj_enforce_relro(Obj_Entry *obj) 5865 { 5866 5867 return (obj_remap_relro(obj, PROT_READ)); 5868 } 5869 5870 static void 5871 map_stacks_exec(RtldLockState *lockstate) 5872 { 5873 void (*thr_map_stacks_exec)(void); 5874 5875 if ((max_stack_flags & PF_X) == 0 || (stack_prot & PROT_EXEC) != 0) 5876 return; 5877 thr_map_stacks_exec = (void (*)(void))(uintptr_t) 5878 get_program_var_addr("__pthread_map_stacks_exec", lockstate); 5879 if (thr_map_stacks_exec != NULL) { 5880 stack_prot |= PROT_EXEC; 5881 thr_map_stacks_exec(); 5882 } 5883 } 5884 5885 static void 5886 distribute_static_tls(Objlist *list, RtldLockState *lockstate) 5887 { 5888 Objlist_Entry *elm; 5889 Obj_Entry *obj; 5890 void (*distrib)(size_t, void *, size_t, size_t); 5891 5892 distrib = (void (*)(size_t, void *, size_t, size_t))(uintptr_t) 5893 get_program_var_addr("__pthread_distribute_static_tls", lockstate); 5894 if (distrib == NULL) 5895 return; 5896 STAILQ_FOREACH(elm, list, link) { 5897 obj = elm->obj; 5898 if (obj->marker || !obj->tls_static || obj->static_tls_copied) 5899 continue; 5900 lock_release(rtld_bind_lock, lockstate); 5901 distrib(obj->tlsoffset, obj->tlsinit, obj->tlsinitsize, 5902 obj->tlssize); 5903 wlock_acquire(rtld_bind_lock, lockstate); 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