1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright 1996, 1997, 1998, 1999, 2000 John D. Polstra. 5 * Copyright 2003 Alexander Kabaev <kan@FreeBSD.ORG>. 6 * Copyright 2009-2013 Konstantin Belousov <kib@FreeBSD.ORG>. 7 * Copyright 2012 John Marino <draco@marino.st>. 8 * Copyright 2014-2017 The FreeBSD Foundation 9 * All rights reserved. 10 * 11 * Portions of this software were developed by Konstantin Belousov 12 * under sponsorship from the FreeBSD Foundation. 13 * 14 * Redistribution and use in source and binary forms, with or without 15 * modification, are permitted provided that the following conditions 16 * are met: 17 * 1. Redistributions of source code must retain the above copyright 18 * notice, this list of conditions and the following disclaimer. 19 * 2. Redistributions in binary form must reproduce the above copyright 20 * notice, this list of conditions and the following disclaimer in the 21 * documentation and/or other materials provided with the distribution. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 24 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 25 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 26 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 27 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 28 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 29 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 30 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 31 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 32 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 33 */ 34 35 /* 36 * Dynamic linker for ELF. 37 * 38 * John Polstra <jdp@polstra.com>. 39 */ 40 41 #include <sys/param.h> 42 #include <sys/ktrace.h> 43 #include <sys/mman.h> 44 #include <sys/mount.h> 45 #include <sys/stat.h> 46 #include <sys/sysctl.h> 47 #include <sys/uio.h> 48 #include <sys/utsname.h> 49 50 #include <dlfcn.h> 51 #include <err.h> 52 #include <errno.h> 53 #include <fcntl.h> 54 #include <stdarg.h> 55 #include <stdio.h> 56 #include <stdlib.h> 57 #include <string.h> 58 #include <unistd.h> 59 60 #include "debug.h" 61 #include "libmap.h" 62 #include "notes.h" 63 #include "rtld.h" 64 #include "rtld_libc.h" 65 #include "rtld_malloc.h" 66 #include "rtld_paths.h" 67 #include "rtld_printf.h" 68 #include "rtld_tls.h" 69 #include "rtld_utrace.h" 70 71 /* Types. */ 72 typedef void (*func_ptr_type)(void); 73 typedef void *(*path_enum_proc)(const char *path, size_t len, void *arg); 74 75 /* Variables that cannot be static: */ 76 extern struct r_debug r_debug; /* For GDB */ 77 extern int _thread_autoinit_dummy_decl; 78 extern void (*__cleanup)(void); 79 80 struct dlerror_save { 81 int seen; 82 char *msg; 83 }; 84 85 struct tcb_list_entry { 86 TAILQ_ENTRY(tcb_list_entry) next; 87 }; 88 89 /* 90 * Function declarations. 91 */ 92 static bool allocate_tls_offset_common(size_t *offp, size_t tlssize, 93 size_t tlsalign, size_t tlspoffset); 94 static const char *basename(const char *); 95 static void digest_dynamic1(Obj_Entry *, int, const Elf_Dyn **, 96 const Elf_Dyn **, const Elf_Dyn **); 97 static bool digest_dynamic2(Obj_Entry *, const Elf_Dyn *, const Elf_Dyn *, 98 const Elf_Dyn *); 99 static bool digest_dynamic(Obj_Entry *, int); 100 static Obj_Entry *digest_phdr(const Elf_Phdr *, int, caddr_t, const char *); 101 static void distribute_static_tls(Objlist *); 102 static Obj_Entry *dlcheck(void *); 103 static int dlclose_locked(void *, RtldLockState *); 104 static Obj_Entry *dlopen_object(const char *name, int fd, Obj_Entry *refobj, 105 int lo_flags, int mode, RtldLockState *lockstate); 106 static Obj_Entry *do_load_object(int, const char *, char *, struct stat *, int); 107 static int do_search_info(const Obj_Entry *obj, int, struct dl_serinfo *); 108 static bool donelist_check(DoneList *, const Obj_Entry *); 109 static void dump_auxv(Elf_Auxinfo **aux_info); 110 static void errmsg_restore(struct dlerror_save *); 111 static struct dlerror_save *errmsg_save(void); 112 static void *fill_search_info(const char *, size_t, void *); 113 static char *find_library(const char *, const Obj_Entry *, int *); 114 static const char *gethints(bool); 115 static void hold_object(Obj_Entry *); 116 static void unhold_object(Obj_Entry *); 117 static void init_dag(Obj_Entry *); 118 static void init_marker(Obj_Entry *); 119 static void init_pagesizes(Elf_Auxinfo **aux_info); 120 static void init_rtld(caddr_t, Elf_Auxinfo **); 121 static void initlist_add_neededs(Needed_Entry *, Objlist *, Objlist *); 122 static void initlist_add_objects(Obj_Entry *, Obj_Entry *, Objlist *, 123 Objlist *); 124 static void initlist_for_loaded_obj(Obj_Entry *obj, Obj_Entry *tail, 125 Objlist *list); 126 static int initlist_objects_ifunc(Objlist *, bool, int, RtldLockState *); 127 static void linkmap_add(Obj_Entry *); 128 static void linkmap_delete(Obj_Entry *); 129 static void load_filtees(Obj_Entry *, int flags, RtldLockState *); 130 static void unload_filtees(Obj_Entry *, RtldLockState *); 131 static int load_needed_objects(Obj_Entry *, int); 132 static int load_preload_objects(const char *, bool); 133 static int load_kpreload(const void *addr); 134 static Obj_Entry *load_object(const char *, int fd, const Obj_Entry *, int); 135 static void map_stacks_exec(RtldLockState *); 136 static int obj_disable_relro(Obj_Entry *); 137 static int obj_enforce_relro(Obj_Entry *); 138 static void objlist_call_fini(Objlist *, Obj_Entry *, RtldLockState *); 139 static void objlist_call_init(Objlist *, RtldLockState *); 140 static void objlist_clear(Objlist *); 141 static Objlist_Entry *objlist_find(Objlist *, const Obj_Entry *); 142 static void objlist_init(Objlist *); 143 static void objlist_push_head(Objlist *, Obj_Entry *); 144 static void objlist_push_tail(Objlist *, Obj_Entry *); 145 static void objlist_put_after(Objlist *, Obj_Entry *, Obj_Entry *); 146 static void objlist_remove(Objlist *, Obj_Entry *); 147 static int open_binary_fd(const char *argv0, bool search_in_path, 148 const char **binpath_res); 149 static int parse_args(char *argv[], int argc, bool *use_pathp, int *fdp, 150 const char **argv0, bool *dir_ignore); 151 static int parse_integer(const char *); 152 static void *path_enumerate(const char *, path_enum_proc, const char *, void *); 153 static void print_usage(const char *argv0); 154 static void release_object(Obj_Entry *); 155 static int relocate_object_dag(Obj_Entry *root, bool bind_now, 156 Obj_Entry *rtldobj, int flags, RtldLockState *lockstate); 157 static int relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, 158 int flags, RtldLockState *lockstate); 159 static int relocate_objects(Obj_Entry *, bool, Obj_Entry *, int, 160 RtldLockState *); 161 static int resolve_object_ifunc(Obj_Entry *, bool, int, RtldLockState *); 162 static int rtld_dirname(const char *, char *); 163 static int rtld_dirname_abs(const char *, char *); 164 static void *rtld_dlopen(const char *name, int fd, int mode); 165 static void rtld_exit(void); 166 static void rtld_nop_exit(void); 167 static char *search_library_path(const char *, const char *, const char *, 168 int *); 169 static char *search_library_pathfds(const char *, const char *, int *); 170 static const void **get_program_var_addr(const char *, RtldLockState *); 171 static void set_program_var(const char *, const void *); 172 static int symlook_default(SymLook *, const Obj_Entry *refobj); 173 static int symlook_global(SymLook *, DoneList *); 174 static void symlook_init_from_req(SymLook *, const SymLook *); 175 static int symlook_list(SymLook *, const Objlist *, DoneList *); 176 static int symlook_needed(SymLook *, const Needed_Entry *, DoneList *); 177 static int symlook_obj1_sysv(SymLook *, const Obj_Entry *); 178 static int symlook_obj1_gnu(SymLook *, const Obj_Entry *); 179 static void *tls_get_addr_slow(struct tcb *, int, size_t, bool) __noinline; 180 static void trace_loaded_objects(Obj_Entry *, bool); 181 static int try_fds_open(const char *name, const char *path); 182 static void unlink_object(Obj_Entry *); 183 static void unload_object(Obj_Entry *, RtldLockState *lockstate); 184 static void unref_dag(Obj_Entry *); 185 static void ref_dag(Obj_Entry *); 186 static char *origin_subst_one(Obj_Entry *, char *, const char *, const char *, 187 bool); 188 static char *origin_subst(Obj_Entry *, const char *); 189 static bool obj_resolve_origin(Obj_Entry *obj); 190 static void preinit_main(void); 191 static void rtld_recalc_bind_not(const char *); 192 static void rtld_recalc_dangerous_ld_env(void); 193 static void rtld_recalc_debug(const char *); 194 static void rtld_recalc_path_rpath(const char *); 195 static int rtld_verify_versions(const Objlist *); 196 static int rtld_verify_object_versions(Obj_Entry *); 197 static void object_add_name(Obj_Entry *, const char *); 198 static int object_match_name(const Obj_Entry *, const char *); 199 static void ld_utrace_log(int, void *, void *, size_t, int, const char *); 200 static void rtld_fill_dl_phdr_info(const Obj_Entry *obj, 201 struct dl_phdr_info *phdr_info); 202 static uint32_t gnu_hash(const char *); 203 static bool matched_symbol(SymLook *, const Obj_Entry *, Sym_Match_Result *, 204 const unsigned long); 205 206 struct ld_env_var_desc; 207 static void rtld_set_var_bind_not(struct ld_env_var_desc *lvd); 208 static void rtld_set_var_bind_now(struct ld_env_var_desc *lvd); 209 static void rtld_set_var_debug(struct ld_env_var_desc *lvd); 210 static void rtld_set_var_dynamic_weak(struct ld_env_var_desc *lvd); 211 static void rtld_set_var_libmap_disable(struct ld_env_var_desc *lvd); 212 static void rtld_set_var_library_path(struct ld_env_var_desc *lvd); 213 static void rtld_set_var_library_path_fds(struct ld_env_var_desc *lvd); 214 static void rtld_set_var_library_path_rpath(struct ld_env_var_desc *lvd); 215 static void rtld_set_var_loadfltr(struct ld_env_var_desc *lvd); 216 217 void r_debug_state(struct r_debug *, struct link_map *) __noinline __exported; 218 void _r_debug_postinit(struct link_map *) __noinline __exported; 219 220 int __sys_openat(int, const char *, int, ...); 221 222 /* 223 * Data declarations. 224 */ 225 struct r_debug r_debug __exported; /* for GDB; */ 226 static bool libmap_disable; /* Disable libmap */ 227 static bool ld_loadfltr; /* Immediate filters processing */ 228 static const char *libmap_override; /* Maps to use in addition to libmap.conf */ 229 static bool trust; /* False for setuid and setgid programs */ 230 static bool dangerous_ld_env; /* True if environment variables have been 231 used to affect the libraries loaded */ 232 bool ld_bind_not; /* Disable PLT update */ 233 static const char *ld_bind_now; /* Environment variable for immediate binding */ 234 static bool ld_dynamic_weak = true; /* True if non-weak definition overrides 235 weak definition */ 236 static const char *ld_library_path; /* Environment variable for search path */ 237 static const char 238 *ld_library_dirs; /* Environment variable for library descriptors */ 239 static const char *ld_preload; /* Environment variable for libraries to 240 load first */ 241 static const char *ld_preload_fds; /* Environment variable for libraries 242 represented by descriptors */ 243 static const char 244 *ld_elf_hints_path; /* Environment variable for alternative hints path */ 245 static const char *ld_tracing; /* Called from ldd to print libs */ 246 static const char *ld_utrace; /* Use utrace() to log events. */ 247 static struct obj_entry_q obj_list; /* Queue of all loaded objects */ 248 static Obj_Entry *obj_main; /* The main program shared object */ 249 static Obj_Entry obj_rtld; /* The dynamic linker shared object */ 250 static unsigned int obj_count; /* Number of objects in obj_list */ 251 static unsigned int obj_loads; /* Number of loads of objects (gen count) */ 252 size_t ld_static_tls_extra = /* Static TLS extra space (bytes) */ 253 RTLD_STATIC_TLS_EXTRA; 254 255 static Objlist list_global = /* Objects dlopened with RTLD_GLOBAL */ 256 STAILQ_HEAD_INITIALIZER(list_global); 257 static Objlist list_main = /* Objects loaded at program startup */ 258 STAILQ_HEAD_INITIALIZER(list_main); 259 static Objlist list_fini = /* Objects needing fini() calls */ 260 STAILQ_HEAD_INITIALIZER(list_fini); 261 262 Elf_Sym sym_zero; /* For resolving undefined weak refs. */ 263 264 #define GDB_STATE(s, m) \ 265 r_debug.r_state = s; \ 266 r_debug_state(&r_debug, m); 267 268 extern Elf_Dyn _DYNAMIC; 269 #pragma weak _DYNAMIC 270 271 int dlclose(void *) __exported; 272 char *dlerror(void) __exported; 273 void *dlopen(const char *, int) __exported; 274 void *fdlopen(int, int) __exported; 275 void *dlsym(void *, const char *) __exported; 276 dlfunc_t dlfunc(void *, const char *) __exported; 277 void *dlvsym(void *, const char *, const char *) __exported; 278 int dladdr(const void *, Dl_info *) __exported; 279 void dllockinit(void *, void *(*)(void *), void (*)(void *), void (*)(void *), 280 void (*)(void *), void (*)(void *), void (*)(void *)) __exported; 281 int dlinfo(void *, int, void *) __exported; 282 int _dl_iterate_phdr_locked(__dl_iterate_hdr_callback, void *) __exported; 283 int dl_iterate_phdr(__dl_iterate_hdr_callback, void *) __exported; 284 int _rtld_addr_phdr(const void *, struct dl_phdr_info *) __exported; 285 int _rtld_get_stack_prot(void) __exported; 286 int _rtld_is_dlopened(void *) __exported; 287 void _rtld_error(const char *, ...) __exported; 288 const char *rtld_get_var(const char *name) __exported; 289 int rtld_set_var(const char *name, const char *val) __exported; 290 291 /* Only here to fix -Wmissing-prototypes warnings */ 292 int __getosreldate(void); 293 func_ptr_type _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp); 294 Elf_Addr _rtld_bind(Obj_Entry *obj, Elf_Size reloff); 295 296 int npagesizes; 297 static int osreldate; 298 size_t *pagesizes; 299 size_t page_size; 300 301 static int stack_prot = PROT_READ | PROT_WRITE | PROT_EXEC; 302 static int max_stack_flags; 303 304 /* 305 * Global declarations normally provided by crt1. The dynamic linker is 306 * not built with crt1, so we have to provide them ourselves. 307 */ 308 char *__progname; 309 char **environ; 310 311 /* 312 * Used to pass argc, argv to init functions. 313 */ 314 int main_argc; 315 char **main_argv; 316 317 /* 318 * Globals to control TLS allocation. 319 */ 320 size_t tls_last_offset; /* Static TLS offset of last module */ 321 size_t tls_last_size; /* Static TLS size of last module */ 322 size_t tls_static_space; /* Static TLS space allocated */ 323 static size_t tls_static_max_align; 324 Elf_Addr tls_dtv_generation = 1; /* Used to detect when dtv size changes */ 325 int tls_max_index = 1; /* Largest module index allocated */ 326 327 static TAILQ_HEAD(, tcb_list_entry) tcb_list = 328 TAILQ_HEAD_INITIALIZER(tcb_list); 329 static size_t tcb_list_entry_offset; 330 331 static bool ld_library_path_rpath = false; 332 bool ld_fast_sigblock = false; 333 334 /* 335 * Globals for path names, and such 336 */ 337 const char *ld_elf_hints_default = _PATH_ELF_HINTS; 338 const char *ld_path_libmap_conf = _PATH_LIBMAP_CONF; 339 const char *ld_path_rtld = _PATH_RTLD; 340 const char *ld_standard_library_path = STANDARD_LIBRARY_PATH; 341 const char *ld_env_prefix = LD_; 342 343 static void (*rtld_exit_ptr)(void); 344 345 #define LD_UTRACE(e, h, mb, ms, r, n) \ 346 do { \ 347 if (ld_utrace != NULL) \ 348 ld_utrace_log(e, h, mb, ms, r, n); \ 349 } while (0) 350 351 static void 352 ld_utrace_log(int event, void *handle, void *mapbase, size_t mapsize, 353 int refcnt, const char *name) 354 { 355 struct utrace_rtld ut; 356 static const char rtld_utrace_sig[RTLD_UTRACE_SIG_SZ] __nonstring = 357 RTLD_UTRACE_SIG; 358 359 memset(&ut, 0, sizeof(ut)); /* clear holes */ 360 memcpy(ut.sig, rtld_utrace_sig, sizeof(ut.sig)); 361 ut.event = event; 362 ut.handle = handle; 363 ut.mapbase = mapbase; 364 ut.mapsize = mapsize; 365 ut.refcnt = refcnt; 366 if (name != NULL) 367 strlcpy(ut.name, name, sizeof(ut.name)); 368 utrace(&ut, sizeof(ut)); 369 } 370 371 struct ld_env_var_desc { 372 const char *const n; 373 const char *val; 374 const bool unsecure : 1; 375 const bool can_update : 1; 376 bool owned : 1; 377 void (*const on_update)(struct ld_env_var_desc *); 378 }; 379 #define LD_ENV_DESC(var, unsec, ...) \ 380 [LD_##var] = { .n = #var, .unsecure = unsec, __VA_ARGS__ } 381 382 static struct ld_env_var_desc ld_env_vars[] = { 383 LD_ENV_DESC(BIND_NOW, false, .can_update = true, 384 .on_update = rtld_set_var_bind_now), 385 LD_ENV_DESC(PRELOAD, true), 386 LD_ENV_DESC(LIBMAP, true), 387 LD_ENV_DESC(LIBRARY_PATH, true, .can_update = true, 388 .on_update = rtld_set_var_library_path), 389 LD_ENV_DESC(LIBRARY_PATH_FDS, true, .can_update = true, 390 .on_update = rtld_set_var_library_path_fds), 391 LD_ENV_DESC(LIBMAP_DISABLE, true, .can_update = true, 392 .on_update = rtld_set_var_libmap_disable), 393 LD_ENV_DESC(BIND_NOT, true, .can_update = true, 394 .on_update = rtld_set_var_bind_not), 395 LD_ENV_DESC(DEBUG, true, .can_update = true, 396 .on_update = rtld_set_var_debug), 397 LD_ENV_DESC(ELF_HINTS_PATH, true), 398 LD_ENV_DESC(LOADFLTR, true, .can_update = true, 399 .on_update = rtld_set_var_loadfltr), 400 LD_ENV_DESC(LIBRARY_PATH_RPATH, true, .can_update = true, 401 .on_update = rtld_set_var_library_path_rpath), 402 LD_ENV_DESC(PRELOAD_FDS, true), 403 LD_ENV_DESC(DYNAMIC_WEAK, true, .can_update = true, 404 .on_update = rtld_set_var_dynamic_weak), 405 LD_ENV_DESC(TRACE_LOADED_OBJECTS, false), 406 LD_ENV_DESC(UTRACE, false, .can_update = true), 407 LD_ENV_DESC(DUMP_REL_PRE, false, .can_update = true), 408 LD_ENV_DESC(DUMP_REL_POST, false, .can_update = true), 409 LD_ENV_DESC(TRACE_LOADED_OBJECTS_PROGNAME, false), 410 LD_ENV_DESC(TRACE_LOADED_OBJECTS_FMT1, false), 411 LD_ENV_DESC(TRACE_LOADED_OBJECTS_FMT2, false), 412 LD_ENV_DESC(TRACE_LOADED_OBJECTS_ALL, false), 413 LD_ENV_DESC(SHOW_AUXV, true), 414 LD_ENV_DESC(STATIC_TLS_EXTRA, false), 415 LD_ENV_DESC(NO_DL_ITERATE_PHDR_AFTER_FORK, false), 416 }; 417 418 const char * 419 ld_get_env_var(int idx) 420 { 421 return (ld_env_vars[idx].val); 422 } 423 424 static const char * 425 rtld_get_env_val(char **env, const char *name, size_t name_len) 426 { 427 char **m, *n, *v; 428 429 for (m = env; *m != NULL; m++) { 430 n = *m; 431 v = strchr(n, '='); 432 if (v == NULL) { 433 /* corrupt environment? */ 434 continue; 435 } 436 if (v - n == (ptrdiff_t)name_len && 437 strncmp(name, n, name_len) == 0) 438 return (v + 1); 439 } 440 return (NULL); 441 } 442 443 static void 444 rtld_init_env_vars_for_prefix(char **env, const char *env_prefix) 445 { 446 struct ld_env_var_desc *lvd; 447 size_t prefix_len, nlen; 448 char **m, *n, *v; 449 int i; 450 451 prefix_len = strlen(env_prefix); 452 for (m = env; *m != NULL; m++) { 453 n = *m; 454 if (strncmp(env_prefix, n, prefix_len) != 0) { 455 /* Not a rtld environment variable. */ 456 continue; 457 } 458 n += prefix_len; 459 v = strchr(n, '='); 460 if (v == NULL) { 461 /* corrupt environment? */ 462 continue; 463 } 464 for (i = 0; i < (int)nitems(ld_env_vars); i++) { 465 lvd = &ld_env_vars[i]; 466 if (lvd->val != NULL) { 467 /* Saw higher-priority variable name already. */ 468 continue; 469 } 470 nlen = strlen(lvd->n); 471 if (v - n == (ptrdiff_t)nlen && 472 strncmp(lvd->n, n, nlen) == 0) { 473 lvd->val = v + 1; 474 break; 475 } 476 } 477 } 478 } 479 480 static void 481 rtld_init_env_vars(char **env) 482 { 483 rtld_init_env_vars_for_prefix(env, ld_env_prefix); 484 } 485 486 static void 487 set_ld_elf_hints_path(void) 488 { 489 if (ld_elf_hints_path == NULL || strlen(ld_elf_hints_path) == 0) 490 ld_elf_hints_path = ld_elf_hints_default; 491 } 492 493 uintptr_t 494 rtld_round_page(uintptr_t x) 495 { 496 return (roundup2(x, page_size)); 497 } 498 499 uintptr_t 500 rtld_trunc_page(uintptr_t x) 501 { 502 return (rounddown2(x, page_size)); 503 } 504 505 /* 506 * Main entry point for dynamic linking. The first argument is the 507 * stack pointer. The stack is expected to be laid out as described 508 * in the SVR4 ABI specification, Intel 386 Processor Supplement. 509 * Specifically, the stack pointer points to a word containing 510 * ARGC. Following that in the stack is a null-terminated sequence 511 * of pointers to argument strings. Then comes a null-terminated 512 * sequence of pointers to environment strings. Finally, there is a 513 * sequence of "auxiliary vector" entries. 514 * 515 * The second argument points to a place to store the dynamic linker's 516 * exit procedure pointer and the third to a place to store the main 517 * program's object. 518 * 519 * The return value is the main program's entry point. 520 */ 521 func_ptr_type 522 _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp) 523 { 524 Elf_Auxinfo *aux, *auxp, *auxpf, *aux_info[AT_COUNT], auxtmp; 525 Objlist_Entry *entry; 526 Obj_Entry *last_interposer, *obj, *preload_tail; 527 const Elf_Phdr *phdr; 528 Objlist initlist; 529 RtldLockState lockstate; 530 struct stat st; 531 Elf_Addr *argcp; 532 char **argv, **env, **envp, *kexecpath; 533 const char *argv0, *binpath, *static_tls_extra; 534 struct ld_env_var_desc *lvd; 535 caddr_t imgentry; 536 char buf[MAXPATHLEN]; 537 int argc, fd, i, mib[4], old_osrel, osrel, phnum, rtld_argc; 538 size_t sz; 539 bool dir_enable, dir_ignore, direct_exec, explicit_fd, search_in_path; 540 541 /* 542 * On entry, the dynamic linker itself has not been relocated yet. 543 * Be very careful not to reference any global data until after 544 * init_rtld has returned. It is OK to reference file-scope statics 545 * and string constants, and to call static and global functions. 546 */ 547 548 /* Find the auxiliary vector on the stack. */ 549 argcp = sp; 550 argc = *sp++; 551 argv = (char **)sp; 552 sp += argc + 1; /* Skip over arguments and NULL terminator */ 553 env = (char **)sp; 554 while (*sp++ != 0) /* Skip over environment, and NULL terminator */ 555 ; 556 aux = (Elf_Auxinfo *)sp; 557 558 /* Digest the auxiliary vector. */ 559 for (i = 0; i < AT_COUNT; i++) 560 aux_info[i] = NULL; 561 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) { 562 if (auxp->a_type < AT_COUNT) 563 aux_info[auxp->a_type] = auxp; 564 } 565 arch_fix_auxv(aux, aux_info); 566 567 /* Initialize and relocate ourselves. */ 568 assert(aux_info[AT_BASE] != NULL); 569 init_rtld((caddr_t)aux_info[AT_BASE]->a_un.a_ptr, aux_info); 570 571 dlerror_dflt_init(); 572 573 __progname = obj_rtld.path; 574 argv0 = argv[0] != NULL ? argv[0] : "(null)"; 575 environ = env; 576 main_argc = argc; 577 main_argv = argv; 578 579 if (aux_info[AT_BSDFLAGS] != NULL && 580 (aux_info[AT_BSDFLAGS]->a_un.a_val & ELF_BSDF_SIGFASTBLK) != 0) 581 ld_fast_sigblock = true; 582 583 trust = !issetugid(); 584 direct_exec = false; 585 586 md_abi_variant_hook(aux_info); 587 rtld_init_env_vars(env); 588 589 fd = -1; 590 if (aux_info[AT_EXECFD] != NULL) { 591 fd = aux_info[AT_EXECFD]->a_un.a_val; 592 } else { 593 assert(aux_info[AT_PHDR] != NULL); 594 phdr = (const Elf_Phdr *)aux_info[AT_PHDR]->a_un.a_ptr; 595 if (phdr == obj_rtld.phdr) { 596 if (!trust) { 597 _rtld_error( 598 "Tainted process refusing to run binary %s", 599 argv0); 600 rtld_die(); 601 } 602 direct_exec = true; 603 604 dbg("opening main program in direct exec mode"); 605 if (argc >= 2) { 606 rtld_argc = parse_args(argv, argc, 607 &search_in_path, &fd, &argv0, &dir_ignore); 608 explicit_fd = (fd != -1); 609 binpath = NULL; 610 if (!explicit_fd) 611 fd = open_binary_fd(argv0, 612 search_in_path, &binpath); 613 if (fstat(fd, &st) == -1) { 614 _rtld_error( 615 "Failed to fstat FD %d (%s): %s", 616 fd, 617 explicit_fd ? 618 "user-provided descriptor" : 619 argv0, 620 rtld_strerror(errno)); 621 rtld_die(); 622 } 623 624 /* 625 * Rough emulation of the permission checks done 626 * by execve(2), only Unix DACs are checked, 627 * ACLs are ignored. Preserve the semantic of 628 * disabling owner to execute if owner x bit is 629 * cleared, even if others x bit is enabled. 630 * mmap(2) does not allow to mmap with PROT_EXEC 631 * if binary' file comes from noexec mount. We 632 * cannot set a text reference on the binary. 633 */ 634 dir_enable = false; 635 if (st.st_uid == geteuid()) { 636 if ((st.st_mode & S_IXUSR) != 0) 637 dir_enable = true; 638 } else if (st.st_gid == getegid()) { 639 if ((st.st_mode & S_IXGRP) != 0) 640 dir_enable = true; 641 } else if ((st.st_mode & S_IXOTH) != 0) { 642 dir_enable = true; 643 } 644 if (!dir_enable && !dir_ignore) { 645 _rtld_error( 646 "No execute permission for binary %s", 647 argv0); 648 rtld_die(); 649 } 650 651 /* 652 * For direct exec mode, argv[0] is the 653 * interpreter name, we must remove it and shift 654 * arguments left before invoking binary main. 655 * Since stack layout places environment 656 * pointers and aux vectors right after the 657 * terminating NULL, we must shift environment 658 * 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, 666 envp); 667 do { 668 *envp = *(envp + rtld_argc); 669 } while (*envp++ != NULL); 670 aux = auxp = (Elf_Auxinfo *)envp; 671 auxpf = (Elf_Auxinfo *)(envp + rtld_argc); 672 dbg("move aux from %p to %p", auxpf, aux); 673 /* 674 * XXXKIB insert place for AT_EXECPATH if not 675 * present 676 */ 677 for (;; auxp++, auxpf++) { 678 /* 679 * NB: Use a temporary since *auxpf and 680 * *auxp overlap if rtld_argc is 1 681 */ 682 auxtmp = *auxpf; 683 *auxp = auxtmp; 684 if (auxp->a_type == AT_NULL) 685 break; 686 } 687 /* 688 * Since the auxiliary vector has moved, 689 * redigest it. 690 */ 691 for (i = 0; i < AT_COUNT; i++) 692 aux_info[i] = NULL; 693 for (auxp = aux; auxp->a_type != AT_NULL; 694 auxp++) { 695 if (auxp->a_type < AT_COUNT) 696 aux_info[auxp->a_type] = auxp; 697 } 698 699 /* 700 * Point AT_EXECPATH auxv and aux_info to the 701 * binary path. 702 */ 703 if (binpath == NULL) { 704 aux_info[AT_EXECPATH] = NULL; 705 } else { 706 if (aux_info[AT_EXECPATH] == NULL) { 707 aux_info[AT_EXECPATH] = xmalloc( 708 sizeof(Elf_Auxinfo)); 709 aux_info[AT_EXECPATH]->a_type = 710 AT_EXECPATH; 711 } 712 aux_info[AT_EXECPATH]->a_un.a_ptr = 713 __DECONST(void *, binpath); 714 } 715 } else { 716 _rtld_error("No binary"); 717 rtld_die(); 718 } 719 } 720 } 721 722 ld_bind_now = ld_get_env_var(LD_BIND_NOW); 723 724 /* 725 * If the process is tainted, then we un-set the dangerous environment 726 * variables. The process will be marked as tainted until setuid(2) 727 * is called. If any child process calls setuid(2) we do not want any 728 * future processes to honor the potentially un-safe variables. 729 */ 730 if (!trust) { 731 for (i = 0; i < (int)nitems(ld_env_vars); i++) { 732 lvd = &ld_env_vars[i]; 733 if (lvd->unsecure) 734 lvd->val = NULL; 735 } 736 } 737 738 rtld_recalc_debug(ld_get_env_var(LD_DEBUG)); 739 rtld_recalc_bind_not(ld_get_env_var(LD_BIND_NOT)); 740 ld_dynamic_weak = ld_get_env_var(LD_DYNAMIC_WEAK) == NULL; 741 libmap_disable = ld_get_env_var(LD_LIBMAP_DISABLE) != NULL; 742 libmap_override = ld_get_env_var(LD_LIBMAP); 743 ld_library_path = ld_get_env_var(LD_LIBRARY_PATH); 744 ld_library_dirs = ld_get_env_var(LD_LIBRARY_PATH_FDS); 745 ld_preload = ld_get_env_var(LD_PRELOAD); 746 ld_preload_fds = ld_get_env_var(LD_PRELOAD_FDS); 747 ld_elf_hints_path = ld_get_env_var(LD_ELF_HINTS_PATH); 748 ld_loadfltr = ld_get_env_var(LD_LOADFLTR) != NULL; 749 rtld_recalc_path_rpath(ld_get_env_var(LD_LIBRARY_PATH_RPATH)); 750 static_tls_extra = ld_get_env_var(LD_STATIC_TLS_EXTRA); 751 if (static_tls_extra != NULL && static_tls_extra[0] != '\0') { 752 sz = parse_integer(static_tls_extra); 753 if (sz >= RTLD_STATIC_TLS_EXTRA && sz <= SIZE_T_MAX) 754 ld_static_tls_extra = sz; 755 } 756 rtld_recalc_dangerous_ld_env(); 757 ld_tracing = ld_get_env_var(LD_TRACE_LOADED_OBJECTS); 758 ld_utrace = ld_get_env_var(LD_UTRACE); 759 760 set_ld_elf_hints_path(); 761 dbg("%s is initialized, base address = %p", __progname, 762 (caddr_t)aux_info[AT_BASE]->a_un.a_ptr); 763 dbg("RTLD dynamic = %p", obj_rtld.dynamic); 764 dbg("RTLD pltgot = %p", obj_rtld.pltgot); 765 766 dbg("initializing thread locks"); 767 lockdflt_init(); 768 769 /* 770 * Load the main program, or process its program header if it is 771 * already loaded. 772 */ 773 if (fd != -1) { /* Load the main program. */ 774 dbg("loading main program"); 775 obj_main = map_object(fd, argv0, NULL, true); 776 close(fd); 777 if (obj_main == NULL) 778 rtld_die(); 779 max_stack_flags = obj_main->stack_flags; 780 } else { /* Main program already loaded. */ 781 dbg("processing main program's program header"); 782 assert(aux_info[AT_PHDR] != NULL); 783 phdr = (const Elf_Phdr *)aux_info[AT_PHDR]->a_un.a_ptr; 784 assert(aux_info[AT_PHNUM] != NULL); 785 phnum = aux_info[AT_PHNUM]->a_un.a_val; 786 assert(aux_info[AT_PHENT] != NULL); 787 assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr)); 788 assert(aux_info[AT_ENTRY] != NULL); 789 imgentry = (caddr_t)aux_info[AT_ENTRY]->a_un.a_ptr; 790 if ((obj_main = digest_phdr(phdr, phnum, imgentry, argv0)) == 791 NULL) 792 rtld_die(); 793 } 794 795 if (aux_info[AT_EXECPATH] != NULL && fd == -1) { 796 kexecpath = aux_info[AT_EXECPATH]->a_un.a_ptr; 797 dbg("AT_EXECPATH %p %s", kexecpath, kexecpath); 798 if (kexecpath[0] == '/') 799 obj_main->path = kexecpath; 800 else if (getcwd(buf, sizeof(buf)) == NULL || 801 strlcat(buf, "/", sizeof(buf)) >= sizeof(buf) || 802 strlcat(buf, kexecpath, sizeof(buf)) >= sizeof(buf)) 803 obj_main->path = xstrdup(argv0); 804 else 805 obj_main->path = xstrdup(buf); 806 } else { 807 dbg("No AT_EXECPATH or direct exec"); 808 obj_main->path = xstrdup(argv0); 809 } 810 dbg("obj_main path %s", obj_main->path); 811 obj_main->mainprog = true; 812 813 if (aux_info[AT_STACKPROT] != NULL && 814 aux_info[AT_STACKPROT]->a_un.a_val != 0) 815 stack_prot = aux_info[AT_STACKPROT]->a_un.a_val; 816 817 #ifndef COMPAT_libcompat 818 /* 819 * Get the actual dynamic linker pathname from the executable if 820 * possible. (It should always be possible.) That ensures that 821 * gdb will find the right dynamic linker even if a non-standard 822 * one is being used. 823 */ 824 if (obj_main->interp != NULL && 825 strcmp(obj_main->interp, obj_rtld.path) != 0) { 826 free(obj_rtld.path); 827 obj_rtld.path = xstrdup(obj_main->interp); 828 __progname = obj_rtld.path; 829 } 830 #endif 831 832 if (!digest_dynamic(obj_main, 0)) 833 rtld_die(); 834 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", 835 obj_main->path, obj_main->valid_hash_sysv, obj_main->valid_hash_gnu, 836 obj_main->dynsymcount); 837 838 linkmap_add(obj_main); 839 linkmap_add(&obj_rtld); 840 LD_UTRACE(UTRACE_LOAD_OBJECT, obj_main, obj_main->mapbase, 841 obj_main->mapsize, 0, obj_main->path); 842 LD_UTRACE(UTRACE_LOAD_OBJECT, &obj_rtld, obj_rtld.mapbase, 843 obj_rtld.mapsize, 0, obj_rtld.path); 844 845 /* Link the main program into the list of objects. */ 846 TAILQ_INSERT_HEAD(&obj_list, obj_main, next); 847 obj_count++; 848 obj_loads++; 849 850 /* Initialize a fake symbol for resolving undefined weak references. */ 851 sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE); 852 sym_zero.st_shndx = SHN_UNDEF; 853 sym_zero.st_value = -(uintptr_t)obj_main->relocbase; 854 855 if (!libmap_disable) 856 libmap_disable = (bool)lm_init(libmap_override); 857 858 if (aux_info[AT_KPRELOAD] != NULL && 859 aux_info[AT_KPRELOAD]->a_un.a_ptr != NULL) { 860 dbg("loading kernel vdso"); 861 if (load_kpreload(aux_info[AT_KPRELOAD]->a_un.a_ptr) == -1) 862 rtld_die(); 863 } 864 865 dbg("loading LD_PRELOAD_FDS libraries"); 866 if (load_preload_objects(ld_preload_fds, true) == -1) 867 rtld_die(); 868 869 dbg("loading LD_PRELOAD libraries"); 870 if (load_preload_objects(ld_preload, false) == -1) 871 rtld_die(); 872 preload_tail = globallist_curr(TAILQ_LAST(&obj_list, obj_entry_q)); 873 874 dbg("loading needed objects"); 875 if (load_needed_objects(obj_main, 876 ld_tracing != NULL ? RTLD_LO_TRACE : 0) == -1) 877 rtld_die(); 878 879 /* Make a list of all objects loaded at startup. */ 880 last_interposer = obj_main; 881 TAILQ_FOREACH(obj, &obj_list, next) { 882 if (obj->marker) 883 continue; 884 if (obj->z_interpose && obj != obj_main) { 885 objlist_put_after(&list_main, last_interposer, obj); 886 last_interposer = obj; 887 } else { 888 objlist_push_tail(&list_main, obj); 889 } 890 obj->refcount++; 891 } 892 893 dbg("checking for required versions"); 894 if (rtld_verify_versions(&list_main) == -1 && !ld_tracing) 895 rtld_die(); 896 897 if (ld_get_env_var(LD_SHOW_AUXV) != NULL) 898 dump_auxv(aux_info); 899 900 if (ld_tracing) { /* We're done */ 901 trace_loaded_objects(obj_main, true); 902 exit(0); 903 } 904 905 if (ld_get_env_var(LD_DUMP_REL_PRE) != NULL) { 906 dump_relocations(obj_main); 907 exit(0); 908 } 909 910 /* 911 * Processing tls relocations requires having the tls offsets 912 * initialized. Prepare offsets before starting initial 913 * relocation processing. 914 */ 915 dbg("initializing initial thread local storage offsets"); 916 STAILQ_FOREACH(entry, &list_main, link) { 917 /* 918 * Allocate all the initial objects out of the static TLS 919 * block even if they didn't ask for it. 920 */ 921 allocate_tls_offset(entry->obj); 922 } 923 924 if (!allocate_tls_offset_common(&tcb_list_entry_offset, 925 sizeof(struct tcb_list_entry), _Alignof(struct tcb_list_entry), 926 0)) { 927 /* 928 * This should be impossible as the static block size is not 929 * yet fixed, but catch and diagnose it failing if that ever 930 * changes or somehow turns out to be false. 931 */ 932 _rtld_error("Could not allocate offset for tcb_list_entry"); 933 rtld_die(); 934 } 935 dbg("tcb_list_entry_offset %zu", tcb_list_entry_offset); 936 937 if (relocate_objects(obj_main, 938 ld_bind_now != NULL && *ld_bind_now != '\0', &obj_rtld, 939 SYMLOOK_EARLY, NULL) == -1) 940 rtld_die(); 941 942 dbg("doing copy relocations"); 943 if (do_copy_relocations(obj_main) == -1) 944 rtld_die(); 945 946 if (ld_get_env_var(LD_DUMP_REL_POST) != NULL) { 947 dump_relocations(obj_main); 948 exit(0); 949 } 950 951 ifunc_init(aux_info); 952 953 /* 954 * Setup TLS for main thread. This must be done after the 955 * relocations are processed, since tls initialization section 956 * might be the subject for relocations. 957 */ 958 dbg("initializing initial thread local storage"); 959 allocate_initial_tls(globallist_curr(TAILQ_FIRST(&obj_list))); 960 961 dbg("initializing key program variables"); 962 set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : ""); 963 set_program_var("environ", env); 964 set_program_var("__elf_aux_vector", aux); 965 966 /* Make a list of init functions to call. */ 967 objlist_init(&initlist); 968 initlist_for_loaded_obj(globallist_curr(TAILQ_FIRST(&obj_list)), 969 preload_tail, &initlist); 970 971 r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */ 972 973 map_stacks_exec(NULL); 974 975 if (!obj_main->crt_no_init) { 976 /* 977 * Make sure we don't call the main program's init and fini 978 * functions for binaries linked with old crt1 which calls 979 * _init itself. 980 */ 981 obj_main->init = obj_main->fini = 0; 982 obj_main->preinit_array = obj_main->init_array = 983 obj_main->fini_array = NULL; 984 } 985 986 if (direct_exec) { 987 /* Set osrel for direct-execed binary */ 988 mib[0] = CTL_KERN; 989 mib[1] = KERN_PROC; 990 mib[2] = KERN_PROC_OSREL; 991 mib[3] = getpid(); 992 osrel = obj_main->osrel; 993 sz = sizeof(old_osrel); 994 dbg("setting osrel to %d", osrel); 995 (void)sysctl(mib, 4, &old_osrel, &sz, &osrel, sizeof(osrel)); 996 } 997 998 wlock_acquire(rtld_bind_lock, &lockstate); 999 1000 dbg("resolving ifuncs"); 1001 if (initlist_objects_ifunc(&initlist, 1002 ld_bind_now != NULL && *ld_bind_now != '\0', SYMLOOK_EARLY, 1003 &lockstate) == -1) 1004 rtld_die(); 1005 1006 rtld_exit_ptr = rtld_exit; 1007 if (obj_main->crt_no_init) 1008 preinit_main(); 1009 objlist_call_init(&initlist, &lockstate); 1010 _r_debug_postinit(&obj_main->linkmap); 1011 objlist_clear(&initlist); 1012 dbg("loading filtees"); 1013 TAILQ_FOREACH(obj, &obj_list, next) { 1014 if (obj->marker) 1015 continue; 1016 if (ld_loadfltr || obj->z_loadfltr) 1017 load_filtees(obj, 0, &lockstate); 1018 } 1019 1020 dbg("enforcing main obj relro"); 1021 if (obj_enforce_relro(obj_main) == -1) 1022 rtld_die(); 1023 1024 lock_release(rtld_bind_lock, &lockstate); 1025 1026 dbg("transferring control to program entry point = %p", 1027 obj_main->entry); 1028 1029 /* Return the exit procedure and the program entry point. */ 1030 *exit_proc = rtld_exit_ptr; 1031 *objp = obj_main; 1032 return ((func_ptr_type)obj_main->entry); 1033 } 1034 1035 /* 1036 * Fill in a DoneList with an allocation large enough to hold all of 1037 * the currently-loaded Keep this as a macro since it calls 1038 * alloca and we want that to occur within the scope of the caller. 1039 */ 1040 #define DLP_ALLOCA_LIMIT 100 /* 800 bytes on LP64 */ 1041 #define donelist_init(_DLP, _REQ) do { \ 1042 DoneList *_dlp = _DLP; \ 1043 SymLook *_r = _REQ; \ 1044 _dlp->num_alloc = obj_count, \ 1045 _dlp->req = NULL; \ 1046 if (_dlp->num_alloc > DLP_ALLOCA_LIMIT) { \ 1047 _dlp->objs = xcalloc(_dlp->num_alloc, sizeof(_dlp->objs[0])); \ 1048 if (_r != NULL && _r->donelist_mem == NULL) { \ 1049 _r->donelist_mem = _dlp->objs; \ 1050 _dlp->req = _r; \ 1051 } \ 1052 } else { \ 1053 _dlp->objs = alloca(_dlp->num_alloc * sizeof(_dlp->objs[0])); \ 1054 } \ 1055 _dlp->num_used = 0; \ 1056 } while (0) 1057 1058 static void 1059 donelist_free(DoneList *dlp) 1060 { 1061 if (dlp->num_alloc > DLP_ALLOCA_LIMIT) 1062 free(dlp->objs); 1063 if (dlp->req != NULL) 1064 dlp->req->donelist_mem = NULL; 1065 } 1066 1067 void * 1068 rtld_resolve_ifunc(const Obj_Entry *obj, const Elf_Sym *def) 1069 { 1070 void *ptr; 1071 Elf_Addr target; 1072 1073 ptr = (void *)make_function_pointer(def, obj); 1074 target = call_ifunc_resolver(ptr); 1075 return ((void *)target); 1076 } 1077 1078 Elf_Addr 1079 _rtld_bind(Obj_Entry *obj, Elf_Size reloff) 1080 { 1081 const Elf_Rel *rel; 1082 const Elf_Sym *def; 1083 const Obj_Entry *defobj; 1084 Elf_Addr *where; 1085 Elf_Addr target; 1086 RtldLockState lockstate; 1087 1088 relock: 1089 rlock_acquire(rtld_bind_lock, &lockstate); 1090 if (sigsetjmp(lockstate.env, 0) != 0) 1091 lock_upgrade(rtld_bind_lock, &lockstate); 1092 if (obj->pltrel) 1093 rel = (const Elf_Rel *)((const char *)obj->pltrel + reloff); 1094 else 1095 rel = (const Elf_Rel *)((const char *)obj->pltrela + reloff); 1096 1097 where = (Elf_Addr *)(obj->relocbase + rel->r_offset); 1098 def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, SYMLOOK_IN_PLT, 1099 NULL, &lockstate); 1100 if (def == NULL) 1101 rtld_die(); 1102 if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) { 1103 if (lockstate_wlocked(&lockstate)) { 1104 lock_release(rtld_bind_lock, &lockstate); 1105 goto relock; 1106 } 1107 target = (Elf_Addr)rtld_resolve_ifunc(defobj, def); 1108 } else { 1109 target = (Elf_Addr)(defobj->relocbase + def->st_value); 1110 } 1111 1112 dbg("\"%s\" in \"%s\" ==> %p in \"%s\"", defobj->strtab + def->st_name, 1113 obj->path == NULL ? NULL : basename(obj->path), (void *)target, 1114 defobj->path == NULL ? NULL : basename(defobj->path)); 1115 1116 /* 1117 * Write the new contents for the jmpslot. Note that depending on 1118 * architecture, the value which we need to return back to the 1119 * lazy binding trampoline may or may not be the target 1120 * address. The value returned from reloc_jmpslot() is the value 1121 * that the trampoline needs. 1122 */ 1123 target = reloc_jmpslot(where, target, defobj, obj, rel); 1124 lock_release(rtld_bind_lock, &lockstate); 1125 return (target); 1126 } 1127 1128 /* 1129 * Error reporting function. Use it like printf. If formats the message 1130 * into a buffer, and sets things up so that the next call to dlerror() 1131 * will return the message. 1132 */ 1133 void 1134 _rtld_error(const char *fmt, ...) 1135 { 1136 va_list ap; 1137 1138 va_start(ap, fmt); 1139 rtld_vsnprintf(lockinfo.dlerror_loc(), lockinfo.dlerror_loc_sz, fmt, 1140 ap); 1141 va_end(ap); 1142 *lockinfo.dlerror_seen() = 0; 1143 dbg("rtld_error: %s", lockinfo.dlerror_loc()); 1144 LD_UTRACE(UTRACE_RTLD_ERROR, NULL, NULL, 0, 0, lockinfo.dlerror_loc()); 1145 } 1146 1147 /* 1148 * Return a dynamically-allocated copy of the current error message, if any. 1149 */ 1150 static struct dlerror_save * 1151 errmsg_save(void) 1152 { 1153 struct dlerror_save *res; 1154 1155 res = xmalloc(sizeof(*res)); 1156 res->seen = *lockinfo.dlerror_seen(); 1157 if (res->seen == 0) 1158 res->msg = xstrdup(lockinfo.dlerror_loc()); 1159 return (res); 1160 } 1161 1162 /* 1163 * Restore the current error message from a copy which was previously saved 1164 * by errmsg_save(). The copy is freed. 1165 */ 1166 static void 1167 errmsg_restore(struct dlerror_save *saved_msg) 1168 { 1169 if (saved_msg == NULL || saved_msg->seen == 1) { 1170 *lockinfo.dlerror_seen() = 1; 1171 } else { 1172 *lockinfo.dlerror_seen() = 0; 1173 strlcpy(lockinfo.dlerror_loc(), saved_msg->msg, 1174 lockinfo.dlerror_loc_sz); 1175 free(saved_msg->msg); 1176 } 1177 free(saved_msg); 1178 } 1179 1180 static const char * 1181 basename(const char *name) 1182 { 1183 const char *p; 1184 1185 p = strrchr(name, '/'); 1186 return (p != NULL ? p + 1 : name); 1187 } 1188 1189 static struct utsname uts; 1190 1191 static char * 1192 origin_subst_one(Obj_Entry *obj, char *real, const char *kw, const char *subst, 1193 bool may_free) 1194 { 1195 char *p, *p1, *res, *resp; 1196 int subst_len, kw_len, subst_count, old_len, new_len; 1197 1198 kw_len = strlen(kw); 1199 1200 /* 1201 * First, count the number of the keyword occurrences, to 1202 * preallocate the final string. 1203 */ 1204 for (p = real, subst_count = 0;; p = p1 + kw_len, subst_count++) { 1205 p1 = strstr(p, kw); 1206 if (p1 == NULL) 1207 break; 1208 } 1209 1210 /* 1211 * If the keyword is not found, just return. 1212 * 1213 * Return non-substituted string if resolution failed. We 1214 * cannot do anything more reasonable, the failure mode of the 1215 * caller is unresolved library anyway. 1216 */ 1217 if (subst_count == 0 || (obj != NULL && !obj_resolve_origin(obj))) 1218 return (may_free ? real : xstrdup(real)); 1219 if (obj != NULL) 1220 subst = obj->origin_path; 1221 1222 /* 1223 * There is indeed something to substitute. Calculate the 1224 * length of the resulting string, and allocate it. 1225 */ 1226 subst_len = strlen(subst); 1227 old_len = strlen(real); 1228 new_len = old_len + (subst_len - kw_len) * subst_count; 1229 res = xmalloc(new_len + 1); 1230 1231 /* 1232 * Now, execute the substitution loop. 1233 */ 1234 for (p = real, resp = res, *resp = '\0';;) { 1235 p1 = strstr(p, kw); 1236 if (p1 != NULL) { 1237 /* Copy the prefix before keyword. */ 1238 memcpy(resp, p, p1 - p); 1239 resp += p1 - p; 1240 /* Keyword replacement. */ 1241 memcpy(resp, subst, subst_len); 1242 resp += subst_len; 1243 *resp = '\0'; 1244 p = p1 + kw_len; 1245 } else 1246 break; 1247 } 1248 1249 /* Copy to the end of string and finish. */ 1250 strcat(resp, p); 1251 if (may_free) 1252 free(real); 1253 return (res); 1254 } 1255 1256 static const struct { 1257 const char *kw; 1258 bool pass_obj; 1259 const char *subst; 1260 } tokens[] = { 1261 { .kw = "$ORIGIN", .pass_obj = true, .subst = NULL }, 1262 { .kw = "${ORIGIN}", .pass_obj = true, .subst = NULL }, 1263 { .kw = "$OSNAME", .pass_obj = false, .subst = uts.sysname }, 1264 { .kw = "${OSNAME}", .pass_obj = false, .subst = uts.sysname }, 1265 { .kw = "$OSREL", .pass_obj = false, .subst = uts.release }, 1266 { .kw = "${OSREL}", .pass_obj = false, .subst = uts.release }, 1267 { .kw = "$PLATFORM", .pass_obj = false, .subst = uts.machine }, 1268 { .kw = "${PLATFORM}", .pass_obj = false, .subst = uts.machine }, 1269 { .kw = "$LIB", .pass_obj = false, .subst = TOKEN_LIB }, 1270 { .kw = "${LIB}", .pass_obj = false, .subst = TOKEN_LIB }, 1271 }; 1272 1273 static char * 1274 origin_subst(Obj_Entry *obj, const char *real) 1275 { 1276 char *res; 1277 int i; 1278 1279 if (obj == NULL || !trust) 1280 return (xstrdup(real)); 1281 if (uts.sysname[0] == '\0') { 1282 if (uname(&uts) != 0) { 1283 _rtld_error("utsname failed: %d", errno); 1284 return (NULL); 1285 } 1286 } 1287 1288 /* __DECONST is safe here since without may_free real is unchanged */ 1289 res = __DECONST(char *, real); 1290 for (i = 0; i < (int)nitems(tokens); i++) { 1291 res = origin_subst_one(tokens[i].pass_obj ? obj : NULL, res, 1292 tokens[i].kw, tokens[i].subst, i != 0); 1293 } 1294 return (res); 1295 } 1296 1297 void 1298 rtld_die(void) 1299 { 1300 const char *msg = dlerror(); 1301 1302 if (msg == NULL) 1303 msg = "Fatal error"; 1304 rtld_fdputstr(STDERR_FILENO, _BASENAME_RTLD ": "); 1305 rtld_fdputstr(STDERR_FILENO, msg); 1306 rtld_fdputchar(STDERR_FILENO, '\n'); 1307 _exit(1); 1308 } 1309 1310 /* 1311 * Process a shared object's DYNAMIC section, and save the important 1312 * information in its Obj_Entry structure. 1313 */ 1314 static void 1315 digest_dynamic1(Obj_Entry *obj, int early, const Elf_Dyn **dyn_rpath, 1316 const Elf_Dyn **dyn_soname, const Elf_Dyn **dyn_runpath) 1317 { 1318 const Elf_Dyn *dynp; 1319 Needed_Entry **needed_tail = &obj->needed; 1320 Needed_Entry **needed_filtees_tail = &obj->needed_filtees; 1321 Needed_Entry **needed_aux_filtees_tail = &obj->needed_aux_filtees; 1322 const Elf_Hashelt *hashtab; 1323 const Elf32_Word *hashval; 1324 Elf32_Word bkt, nmaskwords; 1325 int bloom_size32; 1326 int plttype = DT_REL; 1327 1328 *dyn_rpath = NULL; 1329 *dyn_soname = NULL; 1330 *dyn_runpath = NULL; 1331 1332 obj->bind_now = false; 1333 dynp = obj->dynamic; 1334 if (dynp == NULL) 1335 return; 1336 for (; dynp->d_tag != DT_NULL; dynp++) { 1337 switch (dynp->d_tag) { 1338 case DT_REL: 1339 obj->rel = (const Elf_Rel *)(obj->relocbase + 1340 dynp->d_un.d_ptr); 1341 break; 1342 1343 case DT_RELSZ: 1344 obj->relsize = dynp->d_un.d_val; 1345 break; 1346 1347 case DT_RELENT: 1348 assert(dynp->d_un.d_val == sizeof(Elf_Rel)); 1349 break; 1350 1351 case DT_JMPREL: 1352 obj->pltrel = (const Elf_Rel *)(obj->relocbase + 1353 dynp->d_un.d_ptr); 1354 break; 1355 1356 case DT_PLTRELSZ: 1357 obj->pltrelsize = dynp->d_un.d_val; 1358 break; 1359 1360 case DT_RELA: 1361 obj->rela = (const Elf_Rela *)(obj->relocbase + 1362 dynp->d_un.d_ptr); 1363 break; 1364 1365 case DT_RELASZ: 1366 obj->relasize = dynp->d_un.d_val; 1367 break; 1368 1369 case DT_RELAENT: 1370 assert(dynp->d_un.d_val == sizeof(Elf_Rela)); 1371 break; 1372 1373 case DT_RELR: 1374 obj->relr = (const Elf_Relr *)(obj->relocbase + 1375 dynp->d_un.d_ptr); 1376 break; 1377 1378 case DT_RELRSZ: 1379 obj->relrsize = dynp->d_un.d_val; 1380 break; 1381 1382 case DT_RELRENT: 1383 assert(dynp->d_un.d_val == sizeof(Elf_Relr)); 1384 break; 1385 1386 case DT_PLTREL: 1387 plttype = dynp->d_un.d_val; 1388 assert( 1389 dynp->d_un.d_val == DT_REL || plttype == DT_RELA); 1390 break; 1391 1392 case DT_SYMTAB: 1393 obj->symtab = (const Elf_Sym *)(obj->relocbase + 1394 dynp->d_un.d_ptr); 1395 break; 1396 1397 case DT_SYMENT: 1398 assert(dynp->d_un.d_val == sizeof(Elf_Sym)); 1399 break; 1400 1401 case DT_STRTAB: 1402 obj->strtab = (const char *)(obj->relocbase + 1403 dynp->d_un.d_ptr); 1404 break; 1405 1406 case DT_STRSZ: 1407 obj->strsize = dynp->d_un.d_val; 1408 break; 1409 1410 case DT_VERNEED: 1411 obj->verneed = (const Elf_Verneed *)(obj->relocbase + 1412 dynp->d_un.d_val); 1413 break; 1414 1415 case DT_VERNEEDNUM: 1416 obj->verneednum = dynp->d_un.d_val; 1417 break; 1418 1419 case DT_VERDEF: 1420 obj->verdef = (const Elf_Verdef *)(obj->relocbase + 1421 dynp->d_un.d_val); 1422 break; 1423 1424 case DT_VERDEFNUM: 1425 obj->verdefnum = dynp->d_un.d_val; 1426 break; 1427 1428 case DT_VERSYM: 1429 obj->versyms = (const Elf_Versym *)(obj->relocbase + 1430 dynp->d_un.d_val); 1431 break; 1432 1433 case DT_HASH: { 1434 hashtab = (const Elf_Hashelt *)(obj->relocbase + 1435 dynp->d_un.d_ptr); 1436 obj->nbuckets = hashtab[0]; 1437 obj->nchains = hashtab[1]; 1438 obj->buckets = hashtab + 2; 1439 obj->chains = obj->buckets + obj->nbuckets; 1440 obj->valid_hash_sysv = obj->nbuckets > 0 && 1441 obj->nchains > 0 && obj->buckets != NULL; 1442 } break; 1443 1444 case DT_GNU_HASH: { 1445 hashtab = (const Elf_Hashelt *)(obj->relocbase + 1446 dynp->d_un.d_ptr); 1447 obj->nbuckets_gnu = hashtab[0]; 1448 obj->symndx_gnu = hashtab[1]; 1449 nmaskwords = hashtab[2]; 1450 bloom_size32 = (__ELF_WORD_SIZE / 32) * nmaskwords; 1451 obj->maskwords_bm_gnu = nmaskwords - 1; 1452 obj->shift2_gnu = hashtab[3]; 1453 obj->bloom_gnu = (const Elf_Addr *)(hashtab + 4); 1454 obj->buckets_gnu = hashtab + 4 + bloom_size32; 1455 obj->chain_zero_gnu = obj->buckets_gnu + 1456 obj->nbuckets_gnu - obj->symndx_gnu; 1457 /* Number of bitmask words is required to be power of 2 1458 */ 1459 obj->valid_hash_gnu = powerof2(nmaskwords) && 1460 obj->nbuckets_gnu > 0 && obj->buckets_gnu != NULL; 1461 } break; 1462 1463 case DT_NEEDED: 1464 if (!obj->rtld) { 1465 Needed_Entry *nep = NEW(Needed_Entry); 1466 nep->name = dynp->d_un.d_val; 1467 nep->obj = NULL; 1468 nep->next = NULL; 1469 1470 *needed_tail = nep; 1471 needed_tail = &nep->next; 1472 } 1473 break; 1474 1475 case DT_FILTER: 1476 if (!obj->rtld) { 1477 Needed_Entry *nep = NEW(Needed_Entry); 1478 nep->name = dynp->d_un.d_val; 1479 nep->obj = NULL; 1480 nep->next = NULL; 1481 1482 *needed_filtees_tail = nep; 1483 needed_filtees_tail = &nep->next; 1484 1485 if (obj->linkmap.l_refname == NULL) 1486 obj->linkmap.l_refname = 1487 (char *)dynp->d_un.d_val; 1488 } 1489 break; 1490 1491 case DT_AUXILIARY: 1492 if (!obj->rtld) { 1493 Needed_Entry *nep = NEW(Needed_Entry); 1494 nep->name = dynp->d_un.d_val; 1495 nep->obj = NULL; 1496 nep->next = NULL; 1497 1498 *needed_aux_filtees_tail = nep; 1499 needed_aux_filtees_tail = &nep->next; 1500 } 1501 break; 1502 1503 case DT_PLTGOT: 1504 obj->pltgot = (Elf_Addr *)(obj->relocbase + 1505 dynp->d_un.d_ptr); 1506 break; 1507 1508 case DT_TEXTREL: 1509 obj->textrel = true; 1510 break; 1511 1512 case DT_SYMBOLIC: 1513 obj->symbolic = true; 1514 break; 1515 1516 case DT_RPATH: 1517 /* 1518 * We have to wait until later to process this, because 1519 * we might not have gotten the address of the string 1520 * table yet. 1521 */ 1522 *dyn_rpath = dynp; 1523 break; 1524 1525 case DT_SONAME: 1526 *dyn_soname = dynp; 1527 break; 1528 1529 case DT_RUNPATH: 1530 *dyn_runpath = dynp; 1531 break; 1532 1533 case DT_INIT: 1534 obj->init = (uintptr_t)(obj->relocbase + 1535 dynp->d_un.d_ptr); 1536 break; 1537 1538 case DT_PREINIT_ARRAY: 1539 obj->preinit_array = (uintptr_t *)(obj->relocbase + 1540 dynp->d_un.d_ptr); 1541 break; 1542 1543 case DT_PREINIT_ARRAYSZ: 1544 obj->preinit_array_num = dynp->d_un.d_val / 1545 sizeof(uintptr_t); 1546 break; 1547 1548 case DT_INIT_ARRAY: 1549 obj->init_array = (uintptr_t *)(obj->relocbase + 1550 dynp->d_un.d_ptr); 1551 break; 1552 1553 case DT_INIT_ARRAYSZ: 1554 obj->init_array_num = dynp->d_un.d_val / 1555 sizeof(uintptr_t); 1556 break; 1557 1558 case DT_FINI: 1559 obj->fini = (uintptr_t)(obj->relocbase + 1560 dynp->d_un.d_ptr); 1561 break; 1562 1563 case DT_FINI_ARRAY: 1564 obj->fini_array = (uintptr_t *)(obj->relocbase + 1565 dynp->d_un.d_ptr); 1566 break; 1567 1568 case DT_FINI_ARRAYSZ: 1569 obj->fini_array_num = dynp->d_un.d_val / 1570 sizeof(uintptr_t); 1571 break; 1572 1573 case DT_DEBUG: 1574 if (!early) 1575 dbg("Filling in DT_DEBUG entry"); 1576 (__DECONST(Elf_Dyn *, dynp))->d_un.d_ptr = 1577 (Elf_Addr)&r_debug; 1578 break; 1579 1580 case DT_FLAGS: 1581 if (dynp->d_un.d_val & DF_ORIGIN) 1582 obj->z_origin = true; 1583 if (dynp->d_un.d_val & DF_SYMBOLIC) 1584 obj->symbolic = true; 1585 if (dynp->d_un.d_val & DF_TEXTREL) 1586 obj->textrel = true; 1587 if (dynp->d_un.d_val & DF_BIND_NOW) 1588 obj->bind_now = true; 1589 if (dynp->d_un.d_val & DF_STATIC_TLS) 1590 obj->static_tls = true; 1591 break; 1592 1593 case DT_FLAGS_1: 1594 if (dynp->d_un.d_val & DF_1_NOOPEN) 1595 obj->z_noopen = true; 1596 if (dynp->d_un.d_val & DF_1_ORIGIN) 1597 obj->z_origin = true; 1598 if (dynp->d_un.d_val & DF_1_GLOBAL) 1599 obj->z_global = true; 1600 if (dynp->d_un.d_val & DF_1_BIND_NOW) 1601 obj->bind_now = true; 1602 if (dynp->d_un.d_val & DF_1_NODELETE) 1603 obj->z_nodelete = true; 1604 if (dynp->d_un.d_val & DF_1_LOADFLTR) 1605 obj->z_loadfltr = true; 1606 if (dynp->d_un.d_val & DF_1_INTERPOSE) 1607 obj->z_interpose = true; 1608 if (dynp->d_un.d_val & DF_1_NODEFLIB) 1609 obj->z_nodeflib = true; 1610 if (dynp->d_un.d_val & DF_1_PIE) 1611 obj->z_pie = true; 1612 if (dynp->d_un.d_val & DF_1_INITFIRST) 1613 obj->z_initfirst = true; 1614 break; 1615 1616 default: 1617 if (arch_digest_dynamic(obj, dynp)) 1618 break; 1619 1620 if (!early) { 1621 dbg("Ignoring d_tag %ld = %#lx", 1622 (long)dynp->d_tag, (long)dynp->d_tag); 1623 } 1624 break; 1625 } 1626 } 1627 1628 obj->traced = false; 1629 1630 if (plttype == DT_RELA) { 1631 obj->pltrela = (const Elf_Rela *)obj->pltrel; 1632 obj->pltrel = NULL; 1633 obj->pltrelasize = obj->pltrelsize; 1634 obj->pltrelsize = 0; 1635 } 1636 1637 /* Determine size of dynsym table (equal to nchains of sysv hash) */ 1638 if (obj->valid_hash_sysv) 1639 obj->dynsymcount = obj->nchains; 1640 else if (obj->valid_hash_gnu) { 1641 obj->dynsymcount = 0; 1642 for (bkt = 0; bkt < obj->nbuckets_gnu; bkt++) { 1643 if (obj->buckets_gnu[bkt] == 0) 1644 continue; 1645 hashval = &obj->chain_zero_gnu[obj->buckets_gnu[bkt]]; 1646 do 1647 obj->dynsymcount++; 1648 while ((*hashval++ & 1u) == 0); 1649 } 1650 obj->dynsymcount += obj->symndx_gnu; 1651 } 1652 1653 if (obj->linkmap.l_refname != NULL) 1654 obj->linkmap.l_refname = obj->strtab + 1655 (unsigned long)obj->linkmap.l_refname; 1656 } 1657 1658 static bool 1659 obj_resolve_origin(Obj_Entry *obj) 1660 { 1661 if (obj->origin_path != NULL) 1662 return (true); 1663 obj->origin_path = xmalloc(PATH_MAX); 1664 return (rtld_dirname_abs(obj->path, obj->origin_path) != -1); 1665 } 1666 1667 static bool 1668 digest_dynamic2(Obj_Entry *obj, const Elf_Dyn *dyn_rpath, 1669 const Elf_Dyn *dyn_soname, const Elf_Dyn *dyn_runpath) 1670 { 1671 if (obj->z_origin && !obj_resolve_origin(obj)) 1672 return (false); 1673 1674 if (dyn_runpath != NULL) { 1675 obj->runpath = (const char *)obj->strtab + 1676 dyn_runpath->d_un.d_val; 1677 obj->runpath = origin_subst(obj, obj->runpath); 1678 } else if (dyn_rpath != NULL) { 1679 obj->rpath = (const char *)obj->strtab + dyn_rpath->d_un.d_val; 1680 obj->rpath = origin_subst(obj, obj->rpath); 1681 } 1682 if (dyn_soname != NULL) 1683 object_add_name(obj, obj->strtab + dyn_soname->d_un.d_val); 1684 return (true); 1685 } 1686 1687 static bool 1688 digest_dynamic(Obj_Entry *obj, int early) 1689 { 1690 const Elf_Dyn *dyn_rpath; 1691 const Elf_Dyn *dyn_soname; 1692 const Elf_Dyn *dyn_runpath; 1693 1694 digest_dynamic1(obj, early, &dyn_rpath, &dyn_soname, &dyn_runpath); 1695 return (digest_dynamic2(obj, dyn_rpath, dyn_soname, dyn_runpath)); 1696 } 1697 1698 /* 1699 * Process a shared object's program header. This is used only for the 1700 * main program, when the kernel has already loaded the main program 1701 * into memory before calling the dynamic linker. It creates and 1702 * returns an Obj_Entry structure. 1703 */ 1704 static Obj_Entry * 1705 digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path) 1706 { 1707 Obj_Entry *obj; 1708 const Elf_Phdr *phlimit = phdr + phnum; 1709 const Elf_Phdr *ph; 1710 Elf_Addr note_start, note_end; 1711 int nsegs = 0; 1712 1713 obj = obj_new(); 1714 for (ph = phdr; ph < phlimit; ph++) { 1715 if (ph->p_type != PT_PHDR) 1716 continue; 1717 1718 obj->phdr = phdr; 1719 obj->phnum = ph->p_memsz / sizeof(*ph); 1720 obj->relocbase = __DECONST(char *, phdr) - ph->p_vaddr; 1721 break; 1722 } 1723 1724 obj->stack_flags = PF_X | PF_R | PF_W; 1725 1726 for (ph = phdr; ph < phlimit; ph++) { 1727 switch (ph->p_type) { 1728 case PT_INTERP: 1729 obj->interp = (const char *)(ph->p_vaddr + 1730 obj->relocbase); 1731 break; 1732 1733 case PT_LOAD: 1734 if (nsegs == 0) { /* First load segment */ 1735 obj->vaddrbase = rtld_trunc_page(ph->p_vaddr); 1736 obj->mapbase = obj->vaddrbase + obj->relocbase; 1737 } else { /* Last load segment */ 1738 obj->mapsize = rtld_round_page( 1739 ph->p_vaddr + ph->p_memsz) - 1740 obj->vaddrbase; 1741 } 1742 nsegs++; 1743 break; 1744 1745 case PT_DYNAMIC: 1746 obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + 1747 obj->relocbase); 1748 break; 1749 1750 case PT_TLS: 1751 obj->tlsindex = 1; 1752 obj->tlssize = ph->p_memsz; 1753 obj->tlsalign = ph->p_align; 1754 obj->tlsinitsize = ph->p_filesz; 1755 obj->tlsinit = (void *)(ph->p_vaddr + obj->relocbase); 1756 obj->tlspoffset = ph->p_offset; 1757 break; 1758 1759 case PT_GNU_STACK: 1760 obj->stack_flags = ph->p_flags; 1761 break; 1762 1763 case PT_NOTE: 1764 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; 1765 note_end = note_start + ph->p_filesz; 1766 digest_notes(obj, note_start, note_end); 1767 break; 1768 } 1769 } 1770 if (nsegs < 1) { 1771 _rtld_error("%s: too few PT_LOAD segments", path); 1772 return (NULL); 1773 } 1774 1775 obj->entry = entry; 1776 return (obj); 1777 } 1778 1779 void 1780 digest_notes(Obj_Entry *obj, Elf_Addr note_start, Elf_Addr note_end) 1781 { 1782 const Elf_Note *note; 1783 const char *note_name; 1784 uintptr_t p; 1785 1786 for (note = (const Elf_Note *)note_start; (Elf_Addr)note < note_end; 1787 note = (const Elf_Note *)((const char *)(note + 1) + 1788 roundup2(note->n_namesz, sizeof(Elf32_Addr)) + 1789 roundup2(note->n_descsz, sizeof(Elf32_Addr)))) { 1790 if (arch_digest_note(obj, note)) 1791 continue; 1792 1793 if (note->n_namesz != sizeof(NOTE_FREEBSD_VENDOR) || 1794 note->n_descsz != sizeof(int32_t)) 1795 continue; 1796 if (note->n_type != NT_FREEBSD_ABI_TAG && 1797 note->n_type != NT_FREEBSD_FEATURE_CTL && 1798 note->n_type != NT_FREEBSD_NOINIT_TAG) 1799 continue; 1800 note_name = (const char *)(note + 1); 1801 if (strncmp(NOTE_FREEBSD_VENDOR, note_name, 1802 sizeof(NOTE_FREEBSD_VENDOR)) != 0) 1803 continue; 1804 switch (note->n_type) { 1805 case NT_FREEBSD_ABI_TAG: 1806 /* FreeBSD osrel note */ 1807 p = (uintptr_t)(note + 1); 1808 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1809 obj->osrel = *(const int32_t *)(p); 1810 dbg("note osrel %d", obj->osrel); 1811 break; 1812 case NT_FREEBSD_FEATURE_CTL: 1813 /* FreeBSD ABI feature control note */ 1814 p = (uintptr_t)(note + 1); 1815 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1816 obj->fctl0 = *(const uint32_t *)(p); 1817 dbg("note fctl0 %#x", obj->fctl0); 1818 break; 1819 case NT_FREEBSD_NOINIT_TAG: 1820 /* FreeBSD 'crt does not call init' note */ 1821 obj->crt_no_init = true; 1822 dbg("note crt_no_init"); 1823 break; 1824 } 1825 } 1826 } 1827 1828 static Obj_Entry * 1829 dlcheck(void *handle) 1830 { 1831 Obj_Entry *obj; 1832 1833 TAILQ_FOREACH(obj, &obj_list, next) { 1834 if (obj == (Obj_Entry *)handle) 1835 break; 1836 } 1837 1838 if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) { 1839 _rtld_error("Invalid shared object handle %p", handle); 1840 return (NULL); 1841 } 1842 return (obj); 1843 } 1844 1845 /* 1846 * If the given object is already in the donelist, return true. Otherwise 1847 * add the object to the list and return false. 1848 */ 1849 static bool 1850 donelist_check(DoneList *dlp, const Obj_Entry *obj) 1851 { 1852 unsigned int i; 1853 1854 for (i = 0; i < dlp->num_used; i++) 1855 if (dlp->objs[i] == obj) 1856 return (true); 1857 /* 1858 * Our donelist allocation should always be sufficient. But if 1859 * our threads locking isn't working properly, more shared objects 1860 * could have been loaded since we allocated the list. That should 1861 * never happen, but we'll handle it properly just in case it does. 1862 */ 1863 if (dlp->num_used < dlp->num_alloc) 1864 dlp->objs[dlp->num_used++] = obj; 1865 return (false); 1866 } 1867 1868 /* 1869 * SysV hash function for symbol table lookup. It is a slightly optimized 1870 * version of the hash specified by the System V ABI. 1871 */ 1872 Elf32_Word 1873 elf_hash(const char *name) 1874 { 1875 const unsigned char *p = (const unsigned char *)name; 1876 Elf32_Word h = 0; 1877 1878 while (*p != '\0') { 1879 h = (h << 4) + *p++; 1880 h ^= (h >> 24) & 0xf0; 1881 } 1882 return (h & 0x0fffffff); 1883 } 1884 1885 /* 1886 * The GNU hash function is the Daniel J. Bernstein hash clipped to 32 bits 1887 * unsigned in case it's implemented with a wider type. 1888 */ 1889 static uint32_t 1890 gnu_hash(const char *s) 1891 { 1892 uint32_t h; 1893 unsigned char c; 1894 1895 h = 5381; 1896 for (c = *s; c != '\0'; c = *++s) 1897 h = h * 33 + c; 1898 return (h & 0xffffffff); 1899 } 1900 1901 /* 1902 * Find the library with the given name, and return its full pathname. 1903 * The returned string is dynamically allocated. Generates an error 1904 * message and returns NULL if the library cannot be found. 1905 * 1906 * If the second argument is non-NULL, then it refers to an already- 1907 * loaded shared object, whose library search path will be searched. 1908 * 1909 * If a library is successfully located via LD_LIBRARY_PATH_FDS, its 1910 * descriptor (which is close-on-exec) will be passed out via the third 1911 * argument. 1912 * 1913 * The search order is: 1914 * DT_RPATH in the referencing file _unless_ DT_RUNPATH is present (1) 1915 * DT_RPATH of the main object if DSO without defined DT_RUNPATH (1) 1916 * LD_LIBRARY_PATH 1917 * DT_RUNPATH in the referencing file 1918 * ldconfig hints (if -z nodefaultlib, filter out default library directories 1919 * from list) 1920 * /lib:/usr/lib _unless_ the referencing file is linked with -z nodefaultlib 1921 * 1922 * (1) Handled in digest_dynamic2 - rpath left NULL if runpath defined. 1923 */ 1924 static char * 1925 find_library(const char *xname, const Obj_Entry *refobj, int *fdp) 1926 { 1927 char *pathname, *refobj_path; 1928 const char *name; 1929 bool nodeflib, objgiven; 1930 1931 objgiven = refobj != NULL; 1932 1933 if (libmap_disable || !objgiven || 1934 (name = lm_find(refobj->path, xname)) == NULL) 1935 name = xname; 1936 1937 if (strchr(name, '/') != NULL) { /* Hard coded pathname */ 1938 if (name[0] != '/' && !trust) { 1939 _rtld_error( 1940 "Absolute pathname required for shared object \"%s\"", 1941 name); 1942 return (NULL); 1943 } 1944 return (origin_subst(__DECONST(Obj_Entry *, refobj), 1945 __DECONST(char *, name))); 1946 } 1947 1948 dbg(" Searching for \"%s\"", name); 1949 refobj_path = objgiven ? refobj->path : NULL; 1950 1951 /* 1952 * If refobj->rpath != NULL, then refobj->runpath is NULL. Fall 1953 * back to pre-conforming behaviour if user requested so with 1954 * LD_LIBRARY_PATH_RPATH environment variable and ignore -z 1955 * nodeflib. 1956 */ 1957 if (objgiven && refobj->rpath != NULL && ld_library_path_rpath) { 1958 pathname = search_library_path(name, ld_library_path, 1959 refobj_path, fdp); 1960 if (pathname != NULL) 1961 return (pathname); 1962 if (refobj != NULL) { 1963 pathname = search_library_path(name, refobj->rpath, 1964 refobj_path, fdp); 1965 if (pathname != NULL) 1966 return (pathname); 1967 } 1968 pathname = search_library_pathfds(name, ld_library_dirs, fdp); 1969 if (pathname != NULL) 1970 return (pathname); 1971 pathname = search_library_path(name, gethints(false), 1972 refobj_path, fdp); 1973 if (pathname != NULL) 1974 return (pathname); 1975 pathname = search_library_path(name, ld_standard_library_path, 1976 refobj_path, fdp); 1977 if (pathname != NULL) 1978 return (pathname); 1979 } else { 1980 nodeflib = objgiven ? refobj->z_nodeflib : false; 1981 if (objgiven) { 1982 pathname = search_library_path(name, refobj->rpath, 1983 refobj->path, fdp); 1984 if (pathname != NULL) 1985 return (pathname); 1986 } 1987 if (objgiven && refobj->runpath == NULL && refobj != obj_main) { 1988 pathname = search_library_path(name, obj_main->rpath, 1989 refobj_path, fdp); 1990 if (pathname != NULL) 1991 return (pathname); 1992 } 1993 pathname = search_library_path(name, ld_library_path, 1994 refobj_path, fdp); 1995 if (pathname != NULL) 1996 return (pathname); 1997 if (objgiven) { 1998 pathname = search_library_path(name, refobj->runpath, 1999 refobj_path, fdp); 2000 if (pathname != NULL) 2001 return (pathname); 2002 } 2003 pathname = search_library_pathfds(name, ld_library_dirs, fdp); 2004 if (pathname != NULL) 2005 return (pathname); 2006 pathname = search_library_path(name, gethints(nodeflib), 2007 refobj_path, fdp); 2008 if (pathname != NULL) 2009 return (pathname); 2010 if (objgiven && !nodeflib) { 2011 pathname = search_library_path(name, 2012 ld_standard_library_path, refobj_path, fdp); 2013 if (pathname != NULL) 2014 return (pathname); 2015 } 2016 } 2017 2018 if (objgiven && refobj->path != NULL) { 2019 _rtld_error( 2020 "Shared object \"%s\" not found, required by \"%s\"", 2021 name, basename(refobj->path)); 2022 } else { 2023 _rtld_error("Shared object \"%s\" not found", name); 2024 } 2025 return (NULL); 2026 } 2027 2028 /* 2029 * Given a symbol number in a referencing object, find the corresponding 2030 * definition of the symbol. Returns a pointer to the symbol, or NULL if 2031 * no definition was found. Returns a pointer to the Obj_Entry of the 2032 * defining object via the reference parameter DEFOBJ_OUT. 2033 */ 2034 const Elf_Sym * 2035 find_symdef(unsigned long symnum, const Obj_Entry *refobj, 2036 const Obj_Entry **defobj_out, int flags, SymCache *cache, 2037 RtldLockState *lockstate) 2038 { 2039 const Elf_Sym *ref; 2040 const Elf_Sym *def; 2041 const Obj_Entry *defobj; 2042 const Ver_Entry *ve; 2043 SymLook req; 2044 const char *name; 2045 int res; 2046 2047 /* 2048 * If we have already found this symbol, get the information from 2049 * the cache. 2050 */ 2051 if (symnum >= refobj->dynsymcount) 2052 return (NULL); /* Bad object */ 2053 if (cache != NULL && cache[symnum].sym != NULL) { 2054 *defobj_out = cache[symnum].obj; 2055 return (cache[symnum].sym); 2056 } 2057 2058 ref = refobj->symtab + symnum; 2059 name = refobj->strtab + ref->st_name; 2060 def = NULL; 2061 defobj = NULL; 2062 ve = NULL; 2063 2064 /* 2065 * We don't have to do a full scale lookup if the symbol is local. 2066 * We know it will bind to the instance in this load module; to 2067 * which we already have a pointer (ie ref). By not doing a lookup, 2068 * we not only improve performance, but it also avoids unresolvable 2069 * symbols when local symbols are not in the hash table. This has 2070 * been seen with the ia64 toolchain. 2071 */ 2072 if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) { 2073 if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) { 2074 _rtld_error("%s: Bogus symbol table entry %lu", 2075 refobj->path, symnum); 2076 } 2077 symlook_init(&req, name); 2078 req.flags = flags; 2079 ve = req.ventry = fetch_ventry(refobj, symnum); 2080 req.lockstate = lockstate; 2081 res = symlook_default(&req, refobj); 2082 if (res == 0) { 2083 def = req.sym_out; 2084 defobj = req.defobj_out; 2085 } 2086 } else { 2087 def = ref; 2088 defobj = refobj; 2089 } 2090 2091 /* 2092 * If we found no definition and the reference is weak, treat the 2093 * symbol as having the value zero. 2094 */ 2095 if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) { 2096 def = &sym_zero; 2097 defobj = obj_main; 2098 } 2099 2100 if (def != NULL) { 2101 *defobj_out = defobj; 2102 /* 2103 * Record the information in the cache to avoid subsequent 2104 * lookups. 2105 */ 2106 if (cache != NULL) { 2107 cache[symnum].sym = def; 2108 cache[symnum].obj = defobj; 2109 } 2110 } else { 2111 if (refobj != &obj_rtld) 2112 _rtld_error("%s: Undefined symbol \"%s%s%s\"", 2113 refobj->path, name, ve != NULL ? "@" : "", 2114 ve != NULL ? ve->name : ""); 2115 } 2116 return (def); 2117 } 2118 2119 /* Convert between native byte order and forced little resp. big endian. */ 2120 #define COND_SWAP(n) (is_le ? le32toh(n) : be32toh(n)) 2121 2122 /* 2123 * Return the search path from the ldconfig hints file, reading it if 2124 * necessary. If nostdlib is true, then the default search paths are 2125 * not added to result. 2126 * 2127 * Returns NULL if there are problems with the hints file, 2128 * or if the search path there is empty. 2129 */ 2130 static const char * 2131 gethints(bool nostdlib) 2132 { 2133 static char *filtered_path; 2134 static const char *hints; 2135 static struct elfhints_hdr hdr; 2136 struct fill_search_info_args sargs, hargs; 2137 struct dl_serinfo smeta, hmeta, *SLPinfo, *hintinfo; 2138 struct dl_serpath *SLPpath, *hintpath; 2139 char *p; 2140 struct stat hint_stat; 2141 unsigned int SLPndx, hintndx, fndx, fcount; 2142 int fd; 2143 size_t flen; 2144 uint32_t dl; 2145 uint32_t magic; /* Magic number */ 2146 uint32_t version; /* File version (1) */ 2147 uint32_t strtab; /* Offset of string table in file */ 2148 uint32_t dirlist; /* Offset of directory list in string table */ 2149 uint32_t dirlistlen; /* strlen(dirlist) */ 2150 bool is_le; /* Does the hints file use little endian */ 2151 bool skip; 2152 2153 /* First call, read the hints file */ 2154 if (hints == NULL) { 2155 /* Keep from trying again in case the hints file is bad. */ 2156 hints = ""; 2157 2158 if ((fd = open(ld_elf_hints_path, O_RDONLY | O_CLOEXEC)) == 2159 -1) { 2160 dbg("failed to open hints file \"%s\"", 2161 ld_elf_hints_path); 2162 return (NULL); 2163 } 2164 2165 /* 2166 * Check of hdr.dirlistlen value against type limit 2167 * intends to pacify static analyzers. Further 2168 * paranoia leads to checks that dirlist is fully 2169 * contained in the file range. 2170 */ 2171 if (read(fd, &hdr, sizeof hdr) != sizeof hdr) { 2172 dbg("failed to read %lu bytes from hints file \"%s\"", 2173 (u_long)sizeof hdr, ld_elf_hints_path); 2174 cleanup1: 2175 close(fd); 2176 hdr.dirlistlen = 0; 2177 return (NULL); 2178 } 2179 dbg("host byte-order: %s-endian", 2180 le32toh(1) == 1 ? "little" : "big"); 2181 dbg("hints file byte-order: %s-endian", 2182 hdr.magic == htole32(ELFHINTS_MAGIC) ? "little" : "big"); 2183 is_le = /*htole32(1) == 1 || */ hdr.magic == 2184 htole32(ELFHINTS_MAGIC); 2185 magic = COND_SWAP(hdr.magic); 2186 version = COND_SWAP(hdr.version); 2187 strtab = COND_SWAP(hdr.strtab); 2188 dirlist = COND_SWAP(hdr.dirlist); 2189 dirlistlen = COND_SWAP(hdr.dirlistlen); 2190 if (magic != ELFHINTS_MAGIC) { 2191 dbg("invalid magic number %#08x (expected: %#08x)", 2192 magic, ELFHINTS_MAGIC); 2193 goto cleanup1; 2194 } 2195 if (version != 1) { 2196 dbg("hints file version %d (expected: 1)", version); 2197 goto cleanup1; 2198 } 2199 if (dirlistlen > UINT_MAX / 2) { 2200 dbg("directory list is to long: %d > %d", dirlistlen, 2201 UINT_MAX / 2); 2202 goto cleanup1; 2203 } 2204 if (fstat(fd, &hint_stat) == -1) { 2205 dbg("failed to find length of hints file \"%s\"", 2206 ld_elf_hints_path); 2207 goto cleanup1; 2208 } 2209 dl = strtab; 2210 if (dl + dirlist < dl) { 2211 dbg("invalid string table position %d", dl); 2212 goto cleanup1; 2213 } 2214 dl += dirlist; 2215 if (dl + dirlistlen < dl) { 2216 dbg("invalid directory list offset %d", dirlist); 2217 goto cleanup1; 2218 } 2219 dl += dirlistlen; 2220 if (dl > hint_stat.st_size) { 2221 dbg("hints file \"%s\" is truncated (%d vs. %jd bytes)", 2222 ld_elf_hints_path, dl, 2223 (uintmax_t)hint_stat.st_size); 2224 goto cleanup1; 2225 } 2226 p = xmalloc(dirlistlen + 1); 2227 if (pread(fd, p, dirlistlen + 1, strtab + dirlist) != 2228 (ssize_t)dirlistlen + 1 || p[dirlistlen] != '\0') { 2229 free(p); 2230 dbg( 2231 "failed to read %d bytes starting at %d from hints file \"%s\"", 2232 dirlistlen + 1, strtab + dirlist, 2233 ld_elf_hints_path); 2234 goto cleanup1; 2235 } 2236 hints = p; 2237 close(fd); 2238 } 2239 2240 /* 2241 * If caller agreed to receive list which includes the default 2242 * paths, we are done. Otherwise, if we still did not 2243 * calculated filtered result, do it now. 2244 */ 2245 if (!nostdlib) 2246 return (hints[0] != '\0' ? hints : NULL); 2247 if (filtered_path != NULL) 2248 goto filt_ret; 2249 2250 /* 2251 * Obtain the list of all configured search paths, and the 2252 * list of the default paths. 2253 * 2254 * First estimate the size of the results. 2255 */ 2256 smeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 2257 smeta.dls_cnt = 0; 2258 hmeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 2259 hmeta.dls_cnt = 0; 2260 2261 sargs.request = RTLD_DI_SERINFOSIZE; 2262 sargs.serinfo = &smeta; 2263 hargs.request = RTLD_DI_SERINFOSIZE; 2264 hargs.serinfo = &hmeta; 2265 2266 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 2267 &sargs); 2268 path_enumerate(hints, fill_search_info, NULL, &hargs); 2269 2270 SLPinfo = xmalloc(smeta.dls_size); 2271 hintinfo = xmalloc(hmeta.dls_size); 2272 2273 /* 2274 * Next fetch both sets of paths. 2275 */ 2276 sargs.request = RTLD_DI_SERINFO; 2277 sargs.serinfo = SLPinfo; 2278 sargs.serpath = &SLPinfo->dls_serpath[0]; 2279 sargs.strspace = (char *)&SLPinfo->dls_serpath[smeta.dls_cnt]; 2280 2281 hargs.request = RTLD_DI_SERINFO; 2282 hargs.serinfo = hintinfo; 2283 hargs.serpath = &hintinfo->dls_serpath[0]; 2284 hargs.strspace = (char *)&hintinfo->dls_serpath[hmeta.dls_cnt]; 2285 2286 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 2287 &sargs); 2288 path_enumerate(hints, fill_search_info, NULL, &hargs); 2289 2290 /* 2291 * Now calculate the difference between two sets, by excluding 2292 * standard paths from the full set. 2293 */ 2294 fndx = 0; 2295 fcount = 0; 2296 filtered_path = xmalloc(dirlistlen + 1); 2297 hintpath = &hintinfo->dls_serpath[0]; 2298 for (hintndx = 0; hintndx < hmeta.dls_cnt; hintndx++, hintpath++) { 2299 skip = false; 2300 SLPpath = &SLPinfo->dls_serpath[0]; 2301 /* 2302 * Check each standard path against current. 2303 */ 2304 for (SLPndx = 0; SLPndx < smeta.dls_cnt; SLPndx++, SLPpath++) { 2305 /* matched, skip the path */ 2306 if (!strcmp(hintpath->dls_name, SLPpath->dls_name)) { 2307 skip = true; 2308 break; 2309 } 2310 } 2311 if (skip) 2312 continue; 2313 /* 2314 * Not matched against any standard path, add the path 2315 * to result. Separate consequtive paths with ':'. 2316 */ 2317 if (fcount > 0) { 2318 filtered_path[fndx] = ':'; 2319 fndx++; 2320 } 2321 fcount++; 2322 flen = strlen(hintpath->dls_name); 2323 strncpy((filtered_path + fndx), hintpath->dls_name, flen); 2324 fndx += flen; 2325 } 2326 filtered_path[fndx] = '\0'; 2327 2328 free(SLPinfo); 2329 free(hintinfo); 2330 2331 filt_ret: 2332 return (filtered_path[0] != '\0' ? filtered_path : NULL); 2333 } 2334 2335 static void 2336 init_dag(Obj_Entry *root) 2337 { 2338 const Needed_Entry *needed; 2339 const Objlist_Entry *elm; 2340 DoneList donelist; 2341 2342 if (root->dag_inited) 2343 return; 2344 donelist_init(&donelist, NULL); 2345 2346 /* Root object belongs to own DAG. */ 2347 objlist_push_tail(&root->dldags, root); 2348 objlist_push_tail(&root->dagmembers, root); 2349 donelist_check(&donelist, root); 2350 2351 /* 2352 * Add dependencies of root object to DAG in breadth order 2353 * by exploiting the fact that each new object get added 2354 * to the tail of the dagmembers list. 2355 */ 2356 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2357 for (needed = elm->obj->needed; needed != NULL; 2358 needed = needed->next) { 2359 if (needed->obj == NULL || 2360 donelist_check(&donelist, needed->obj)) 2361 continue; 2362 objlist_push_tail(&needed->obj->dldags, root); 2363 objlist_push_tail(&root->dagmembers, needed->obj); 2364 } 2365 } 2366 root->dag_inited = true; 2367 donelist_free(&donelist); 2368 } 2369 2370 static void 2371 init_marker(Obj_Entry *marker) 2372 { 2373 bzero(marker, sizeof(*marker)); 2374 marker->marker = true; 2375 } 2376 2377 Obj_Entry * 2378 globallist_curr(const Obj_Entry *obj) 2379 { 2380 for (;;) { 2381 if (obj == NULL) 2382 return (NULL); 2383 if (!obj->marker) 2384 return (__DECONST(Obj_Entry *, obj)); 2385 obj = TAILQ_PREV(obj, obj_entry_q, next); 2386 } 2387 } 2388 2389 Obj_Entry * 2390 globallist_next(const Obj_Entry *obj) 2391 { 2392 for (;;) { 2393 obj = TAILQ_NEXT(obj, next); 2394 if (obj == NULL) 2395 return (NULL); 2396 if (!obj->marker) 2397 return (__DECONST(Obj_Entry *, obj)); 2398 } 2399 } 2400 2401 /* Prevent the object from being unmapped while the bind lock is dropped. */ 2402 static void 2403 hold_object(Obj_Entry *obj) 2404 { 2405 obj->holdcount++; 2406 } 2407 2408 static void 2409 unhold_object(Obj_Entry *obj) 2410 { 2411 assert(obj->holdcount > 0); 2412 if (--obj->holdcount == 0 && obj->unholdfree) 2413 release_object(obj); 2414 } 2415 2416 static void 2417 process_z(Obj_Entry *root) 2418 { 2419 const Objlist_Entry *elm; 2420 Obj_Entry *obj; 2421 2422 /* 2423 * Walk over object DAG and process every dependent object 2424 * that is marked as DF_1_NODELETE or DF_1_GLOBAL. They need 2425 * to grow their own DAG. 2426 * 2427 * For DF_1_GLOBAL, DAG is required for symbol lookups in 2428 * symlook_global() to work. 2429 * 2430 * For DF_1_NODELETE, the DAG should have its reference upped. 2431 */ 2432 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2433 obj = elm->obj; 2434 if (obj == NULL) 2435 continue; 2436 if (obj->z_nodelete && !obj->ref_nodel) { 2437 dbg("obj %s -z nodelete", obj->path); 2438 init_dag(obj); 2439 ref_dag(obj); 2440 obj->ref_nodel = true; 2441 } 2442 if (obj->z_global && objlist_find(&list_global, obj) == NULL) { 2443 dbg("obj %s -z global", obj->path); 2444 objlist_push_tail(&list_global, obj); 2445 init_dag(obj); 2446 } 2447 } 2448 } 2449 2450 static void 2451 parse_rtld_phdr(Obj_Entry *obj) 2452 { 2453 const Elf_Phdr *ph; 2454 Elf_Addr note_start, note_end; 2455 bool first_seg; 2456 2457 first_seg = true; 2458 obj->stack_flags = PF_X | PF_R | PF_W; 2459 for (ph = obj->phdr; ph < obj->phdr + obj->phnum; ph++) { 2460 switch (ph->p_type) { 2461 case PT_LOAD: 2462 if (first_seg) { 2463 obj->vaddrbase = rtld_trunc_page(ph->p_vaddr); 2464 first_seg = false; 2465 } 2466 obj->mapsize = rtld_round_page(ph->p_vaddr + 2467 ph->p_memsz) - obj->vaddrbase; 2468 break; 2469 case PT_GNU_STACK: 2470 obj->stack_flags = ph->p_flags; 2471 break; 2472 case PT_NOTE: 2473 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; 2474 note_end = note_start + ph->p_filesz; 2475 digest_notes(obj, note_start, note_end); 2476 break; 2477 } 2478 } 2479 } 2480 2481 /* 2482 * Initialize the dynamic linker. The argument is the address at which 2483 * the dynamic linker has been mapped into memory. The primary task of 2484 * this function is to relocate the dynamic linker. 2485 */ 2486 static void 2487 init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info) 2488 { 2489 Obj_Entry objtmp; /* Temporary rtld object */ 2490 const Elf_Ehdr *ehdr; 2491 const Elf_Dyn *dyn_rpath; 2492 const Elf_Dyn *dyn_soname; 2493 const Elf_Dyn *dyn_runpath; 2494 2495 /* 2496 * Conjure up an Obj_Entry structure for the dynamic linker. 2497 * 2498 * The "path" member can't be initialized yet because string constants 2499 * cannot yet be accessed. Below we will set it correctly. 2500 */ 2501 memset(&objtmp, 0, sizeof(objtmp)); 2502 objtmp.path = NULL; 2503 objtmp.rtld = true; 2504 objtmp.mapbase = mapbase; 2505 #ifdef PIC 2506 objtmp.relocbase = mapbase; 2507 #endif 2508 2509 objtmp.dynamic = rtld_dynamic(&objtmp); 2510 digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname, &dyn_runpath); 2511 assert(objtmp.needed == NULL); 2512 assert(!objtmp.textrel); 2513 /* 2514 * Temporarily put the dynamic linker entry into the object list, so 2515 * that symbols can be found. 2516 */ 2517 relocate_objects(&objtmp, true, &objtmp, 0, NULL); 2518 2519 ehdr = (Elf_Ehdr *)mapbase; 2520 objtmp.phdr = (Elf_Phdr *)((char *)mapbase + ehdr->e_phoff); 2521 objtmp.phnum = ehdr->e_phnum; 2522 2523 /* Initialize the object list. */ 2524 TAILQ_INIT(&obj_list); 2525 2526 /* Now that non-local variables can be accesses, copy out obj_rtld. */ 2527 memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld)); 2528 2529 /* The page size is required by the dynamic memory allocator. */ 2530 init_pagesizes(aux_info); 2531 2532 if (aux_info[AT_OSRELDATE] != NULL) 2533 osreldate = aux_info[AT_OSRELDATE]->a_un.a_val; 2534 2535 digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname, dyn_runpath); 2536 2537 /* Replace the path with a dynamically allocated copy. */ 2538 obj_rtld.path = xstrdup(ld_path_rtld); 2539 2540 parse_rtld_phdr(&obj_rtld); 2541 if (obj_enforce_relro(&obj_rtld) == -1) 2542 rtld_die(); 2543 2544 r_debug.r_version = R_DEBUG_VERSION; 2545 r_debug.r_brk = r_debug_state; 2546 r_debug.r_state = RT_CONSISTENT; 2547 r_debug.r_ldbase = obj_rtld.relocbase; 2548 } 2549 2550 /* 2551 * Retrieve the array of supported page sizes. The kernel provides the page 2552 * sizes in increasing order. 2553 */ 2554 static void 2555 init_pagesizes(Elf_Auxinfo **aux_info) 2556 { 2557 static size_t psa[MAXPAGESIZES]; 2558 int mib[2]; 2559 size_t len, size; 2560 2561 if (aux_info[AT_PAGESIZES] != NULL && 2562 aux_info[AT_PAGESIZESLEN] != NULL) { 2563 size = aux_info[AT_PAGESIZESLEN]->a_un.a_val; 2564 pagesizes = aux_info[AT_PAGESIZES]->a_un.a_ptr; 2565 } else { 2566 len = 2; 2567 if (sysctlnametomib("hw.pagesizes", mib, &len) == 0) 2568 size = sizeof(psa); 2569 else { 2570 /* As a fallback, retrieve the base page size. */ 2571 size = sizeof(psa[0]); 2572 if (aux_info[AT_PAGESZ] != NULL) { 2573 psa[0] = aux_info[AT_PAGESZ]->a_un.a_val; 2574 goto psa_filled; 2575 } else { 2576 mib[0] = CTL_HW; 2577 mib[1] = HW_PAGESIZE; 2578 len = 2; 2579 } 2580 } 2581 if (sysctl(mib, len, psa, &size, NULL, 0) == -1) { 2582 _rtld_error("sysctl for hw.pagesize(s) failed"); 2583 rtld_die(); 2584 } 2585 psa_filled: 2586 pagesizes = psa; 2587 } 2588 npagesizes = size / sizeof(pagesizes[0]); 2589 /* Discard any invalid entries at the end of the array. */ 2590 while (npagesizes > 0 && pagesizes[npagesizes - 1] == 0) 2591 npagesizes--; 2592 2593 page_size = pagesizes[0]; 2594 } 2595 2596 /* 2597 * Add the init functions from a needed object list (and its recursive 2598 * needed objects) to "list". This is not used directly; it is a helper 2599 * function for initlist_add_objects(). The write lock must be held 2600 * when this function is called. 2601 */ 2602 static void 2603 initlist_add_neededs(Needed_Entry *needed, Objlist *list, Objlist *iflist) 2604 { 2605 /* Recursively process the successor needed objects. */ 2606 if (needed->next != NULL) 2607 initlist_add_neededs(needed->next, list, iflist); 2608 2609 /* Process the current needed object. */ 2610 if (needed->obj != NULL) 2611 initlist_add_objects(needed->obj, needed->obj, list, iflist); 2612 } 2613 2614 /* 2615 * Scan all of the DAGs rooted in the range of objects from "obj" to 2616 * "tail" and add their init functions to "list". This recurses over 2617 * the DAGs and ensure the proper init ordering such that each object's 2618 * needed libraries are initialized before the object itself. At the 2619 * same time, this function adds the objects to the global finalization 2620 * list "list_fini" in the opposite order. The write lock must be 2621 * held when this function is called. 2622 */ 2623 static void 2624 initlist_for_loaded_obj(Obj_Entry *obj, Obj_Entry *tail, Objlist *list) 2625 { 2626 Objlist iflist; /* initfirst objs and their needed */ 2627 Objlist_Entry *tmp; 2628 2629 objlist_init(&iflist); 2630 initlist_add_objects(obj, tail, list, &iflist); 2631 2632 STAILQ_FOREACH(tmp, &iflist, link) { 2633 Obj_Entry *tobj = tmp->obj; 2634 2635 if ((tobj->fini != 0 || tobj->fini_array != NULL) && 2636 !tobj->on_fini_list) { 2637 objlist_push_tail(&list_fini, tobj); 2638 tobj->on_fini_list = true; 2639 } 2640 } 2641 2642 /* 2643 * This might result in the same object appearing more 2644 * than once on the init list. objlist_call_init() 2645 * uses obj->init_scanned to avoid dup calls. 2646 */ 2647 STAILQ_REVERSE(&iflist, Struct_Objlist_Entry, link); 2648 STAILQ_FOREACH(tmp, &iflist, link) 2649 objlist_push_head(list, tmp->obj); 2650 2651 objlist_clear(&iflist); 2652 } 2653 2654 static void 2655 initlist_add_objects(Obj_Entry *obj, Obj_Entry *tail, Objlist *list, 2656 Objlist *iflist) 2657 { 2658 Obj_Entry *nobj; 2659 2660 if (obj->init_done) 2661 return; 2662 2663 if (obj->z_initfirst || list == NULL) { 2664 /* 2665 * Ignore obj->init_scanned. The object might indeed 2666 * already be on the init list, but due to being 2667 * needed by an initfirst object, we must put it at 2668 * the head of the init list. obj->init_done protects 2669 * against double-initialization. 2670 */ 2671 if (obj->needed != NULL) 2672 initlist_add_neededs(obj->needed, NULL, iflist); 2673 if (obj->needed_filtees != NULL) 2674 initlist_add_neededs(obj->needed_filtees, NULL, 2675 iflist); 2676 if (obj->needed_aux_filtees != NULL) 2677 initlist_add_neededs(obj->needed_aux_filtees, 2678 NULL, iflist); 2679 objlist_push_tail(iflist, obj); 2680 2681 /* Recursively process the successor objects. */ 2682 nobj = globallist_next(obj); 2683 if (nobj != NULL && obj != tail) 2684 initlist_add_objects(nobj, tail, list, iflist); 2685 } else { 2686 if (obj->init_scanned) 2687 return; 2688 obj->init_scanned = true; 2689 2690 /* Recursively process the successor objects. */ 2691 nobj = globallist_next(obj); 2692 if (nobj != NULL && obj != tail) 2693 initlist_add_objects(nobj, tail, list, iflist); 2694 2695 /* Recursively process the needed objects. */ 2696 if (obj->needed != NULL) 2697 initlist_add_neededs(obj->needed, list, iflist); 2698 if (obj->needed_filtees != NULL) 2699 initlist_add_neededs(obj->needed_filtees, list, 2700 iflist); 2701 if (obj->needed_aux_filtees != NULL) 2702 initlist_add_neededs(obj->needed_aux_filtees, list, 2703 iflist); 2704 2705 /* Add the object to the init list. */ 2706 objlist_push_tail(list, obj); 2707 2708 /* 2709 * Add the object to the global fini list in the 2710 * reverse order. 2711 */ 2712 if ((obj->fini != 0 || obj->fini_array != NULL) && 2713 !obj->on_fini_list) { 2714 objlist_push_head(&list_fini, obj); 2715 obj->on_fini_list = true; 2716 } 2717 } 2718 } 2719 2720 static void 2721 free_needed_filtees(Needed_Entry *n, RtldLockState *lockstate) 2722 { 2723 Needed_Entry *needed, *needed1; 2724 2725 for (needed = n; needed != NULL; needed = needed->next) { 2726 if (needed->obj != NULL) { 2727 dlclose_locked(needed->obj, lockstate); 2728 needed->obj = NULL; 2729 } 2730 } 2731 for (needed = n; needed != NULL; needed = needed1) { 2732 needed1 = needed->next; 2733 free(needed); 2734 } 2735 } 2736 2737 static void 2738 unload_filtees(Obj_Entry *obj, RtldLockState *lockstate) 2739 { 2740 free_needed_filtees(obj->needed_filtees, lockstate); 2741 obj->needed_filtees = NULL; 2742 free_needed_filtees(obj->needed_aux_filtees, lockstate); 2743 obj->needed_aux_filtees = NULL; 2744 obj->filtees_loaded = false; 2745 } 2746 2747 static void 2748 load_filtee1(Obj_Entry *obj, Needed_Entry *needed, int flags, 2749 RtldLockState *lockstate) 2750 { 2751 for (; needed != NULL; needed = needed->next) { 2752 needed->obj = dlopen_object(obj->strtab + needed->name, -1, obj, 2753 flags, ((ld_loadfltr || obj->z_loadfltr) ? RTLD_NOW : 2754 RTLD_LAZY) | RTLD_LOCAL, lockstate); 2755 } 2756 } 2757 2758 static void 2759 load_filtees(Obj_Entry *obj, int flags, RtldLockState *lockstate) 2760 { 2761 if (obj->filtees_loaded || obj->filtees_loading) 2762 return; 2763 lock_restart_for_upgrade(lockstate); 2764 obj->filtees_loading = true; 2765 load_filtee1(obj, obj->needed_filtees, flags, lockstate); 2766 load_filtee1(obj, obj->needed_aux_filtees, flags, lockstate); 2767 obj->filtees_loaded = true; 2768 obj->filtees_loading = false; 2769 } 2770 2771 static int 2772 process_needed(Obj_Entry *obj, Needed_Entry *needed, int flags) 2773 { 2774 Obj_Entry *obj1; 2775 2776 for (; needed != NULL; needed = needed->next) { 2777 obj1 = needed->obj = load_object(obj->strtab + needed->name, -1, 2778 obj, flags & ~RTLD_LO_NOLOAD); 2779 if (obj1 == NULL && !ld_tracing && 2780 (flags & RTLD_LO_FILTEES) == 0) 2781 return (-1); 2782 } 2783 return (0); 2784 } 2785 2786 /* 2787 * Given a shared object, traverse its list of needed objects, and load 2788 * each of them. Returns 0 on success. Generates an error message and 2789 * returns -1 on failure. 2790 */ 2791 static int 2792 load_needed_objects(Obj_Entry *first, int flags) 2793 { 2794 Obj_Entry *obj; 2795 2796 for (obj = first; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 2797 if (obj->marker) 2798 continue; 2799 if (process_needed(obj, obj->needed, flags) == -1) 2800 return (-1); 2801 } 2802 return (0); 2803 } 2804 2805 static int 2806 load_preload_objects(const char *penv, bool isfd) 2807 { 2808 Obj_Entry *obj; 2809 const char *name; 2810 size_t len; 2811 char savech, *p, *psave; 2812 int fd; 2813 static const char delim[] = " \t:;"; 2814 2815 if (penv == NULL) 2816 return (0); 2817 2818 p = psave = xstrdup(penv); 2819 p += strspn(p, delim); 2820 while (*p != '\0') { 2821 len = strcspn(p, delim); 2822 2823 savech = p[len]; 2824 p[len] = '\0'; 2825 if (isfd) { 2826 name = NULL; 2827 fd = parse_integer(p); 2828 if (fd == -1) { 2829 free(psave); 2830 return (-1); 2831 } 2832 } else { 2833 name = p; 2834 fd = -1; 2835 } 2836 2837 obj = load_object(name, fd, NULL, 0); 2838 if (obj == NULL) { 2839 free(psave); 2840 return (-1); /* XXX - cleanup */ 2841 } 2842 obj->z_interpose = true; 2843 p[len] = savech; 2844 p += len; 2845 p += strspn(p, delim); 2846 } 2847 LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL); 2848 2849 free(psave); 2850 return (0); 2851 } 2852 2853 static const char * 2854 printable_path(const char *path) 2855 { 2856 return (path == NULL ? "<unknown>" : path); 2857 } 2858 2859 /* 2860 * Load a shared object into memory, if it is not already loaded. The 2861 * object may be specified by name or by user-supplied file descriptor 2862 * fd_u. In the later case, the fd_u descriptor is not closed, but its 2863 * duplicate is. 2864 * 2865 * Returns a pointer to the Obj_Entry for the object. Returns NULL 2866 * on failure. 2867 */ 2868 static Obj_Entry * 2869 load_object(const char *name, int fd_u, const Obj_Entry *refobj, int flags) 2870 { 2871 Obj_Entry *obj; 2872 int fd; 2873 struct stat sb; 2874 char *path; 2875 2876 fd = -1; 2877 if (name != NULL) { 2878 TAILQ_FOREACH(obj, &obj_list, next) { 2879 if (obj->marker || obj->doomed) 2880 continue; 2881 if (object_match_name(obj, name)) 2882 return (obj); 2883 } 2884 2885 path = find_library(name, refobj, &fd); 2886 if (path == NULL) 2887 return (NULL); 2888 } else 2889 path = NULL; 2890 2891 if (fd >= 0) { 2892 /* 2893 * search_library_pathfds() opens a fresh file descriptor for 2894 * the library, so there is no need to dup(). 2895 */ 2896 } else if (fd_u == -1) { 2897 /* 2898 * If we didn't find a match by pathname, or the name is not 2899 * supplied, open the file and check again by device and inode. 2900 * This avoids false mismatches caused by multiple links or ".." 2901 * in pathnames. 2902 * 2903 * To avoid a race, we open the file and use fstat() rather than 2904 * using stat(). 2905 */ 2906 if ((fd = open(path, O_RDONLY | O_CLOEXEC | O_VERIFY)) == -1) { 2907 fd = try_fds_open(path, ld_library_dirs); 2908 if (fd == -1) { 2909 _rtld_error("Cannot open \"%s\"", path); 2910 free(path); 2911 return (NULL); 2912 } 2913 } 2914 } else { 2915 fd = fcntl(fd_u, F_DUPFD_CLOEXEC, 0); 2916 if (fd == -1) { 2917 _rtld_error("Cannot dup fd"); 2918 free(path); 2919 return (NULL); 2920 } 2921 } 2922 if (fstat(fd, &sb) == -1) { 2923 _rtld_error("Cannot fstat \"%s\"", printable_path(path)); 2924 close(fd); 2925 free(path); 2926 return (NULL); 2927 } 2928 TAILQ_FOREACH(obj, &obj_list, next) { 2929 if (obj->marker || obj->doomed) 2930 continue; 2931 if (obj->ino == sb.st_ino && obj->dev == sb.st_dev) 2932 break; 2933 } 2934 if (obj != NULL) { 2935 if (name != NULL) 2936 object_add_name(obj, name); 2937 free(path); 2938 close(fd); 2939 return (obj); 2940 } 2941 if (flags & RTLD_LO_NOLOAD) { 2942 free(path); 2943 close(fd); 2944 return (NULL); 2945 } 2946 2947 /* First use of this object, so we must map it in */ 2948 obj = do_load_object(fd, name, path, &sb, flags); 2949 if (obj == NULL) 2950 free(path); 2951 close(fd); 2952 2953 return (obj); 2954 } 2955 2956 static Obj_Entry * 2957 do_load_object(int fd, const char *name, char *path, struct stat *sbp, 2958 int flags) 2959 { 2960 Obj_Entry *obj; 2961 struct statfs fs; 2962 2963 /* 2964 * First, make sure that environment variables haven't been 2965 * used to circumvent the noexec flag on a filesystem. 2966 * We ignore fstatfs(2) failures, since fd might reference 2967 * not a file, e.g. shmfd. 2968 */ 2969 if (dangerous_ld_env && fstatfs(fd, &fs) == 0 && 2970 (fs.f_flags & MNT_NOEXEC) != 0) { 2971 _rtld_error("Cannot execute objects on %s", fs.f_mntonname); 2972 return (NULL); 2973 } 2974 2975 dbg("loading \"%s\"", printable_path(path)); 2976 obj = map_object(fd, printable_path(path), sbp, false); 2977 if (obj == NULL) 2978 return (NULL); 2979 2980 /* 2981 * If DT_SONAME is present in the object, digest_dynamic2 already 2982 * added it to the object names. 2983 */ 2984 if (name != NULL) 2985 object_add_name(obj, name); 2986 obj->path = path; 2987 if (!digest_dynamic(obj, 0)) 2988 goto errp; 2989 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", obj->path, 2990 obj->valid_hash_sysv, obj->valid_hash_gnu, obj->dynsymcount); 2991 if (obj->z_pie && (flags & RTLD_LO_TRACE) == 0) { 2992 dbg("refusing to load PIE executable \"%s\"", obj->path); 2993 _rtld_error("Cannot load PIE binary %s as DSO", obj->path); 2994 goto errp; 2995 } 2996 if (obj->z_noopen && 2997 (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) == RTLD_LO_DLOPEN) { 2998 dbg("refusing to load non-loadable \"%s\"", obj->path); 2999 _rtld_error("Cannot dlopen non-loadable %s", obj->path); 3000 goto errp; 3001 } 3002 3003 obj->dlopened = (flags & RTLD_LO_DLOPEN) != 0; 3004 TAILQ_INSERT_TAIL(&obj_list, obj, next); 3005 obj_count++; 3006 obj_loads++; 3007 linkmap_add(obj); /* for GDB & dlinfo() */ 3008 max_stack_flags |= obj->stack_flags; 3009 3010 dbg(" %p .. %p: %s", obj->mapbase, obj->mapbase + obj->mapsize - 1, 3011 obj->path); 3012 if (obj->textrel) 3013 dbg(" WARNING: %s has impure text", obj->path); 3014 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 3015 obj->path); 3016 3017 return (obj); 3018 3019 errp: 3020 munmap(obj->mapbase, obj->mapsize); 3021 obj_free(obj); 3022 return (NULL); 3023 } 3024 3025 static int 3026 load_kpreload(const void *addr) 3027 { 3028 Obj_Entry *obj; 3029 const Elf_Ehdr *ehdr; 3030 const Elf_Phdr *phdr, *phlimit, *phdyn, *seg0, *segn; 3031 static const char kname[] = "[vdso]"; 3032 3033 ehdr = addr; 3034 if (!check_elf_headers(ehdr, "kpreload")) 3035 return (-1); 3036 obj = obj_new(); 3037 phdr = (const Elf_Phdr *)((const char *)addr + ehdr->e_phoff); 3038 obj->phdr = phdr; 3039 obj->phnum = ehdr->e_phnum; 3040 phlimit = phdr + ehdr->e_phnum; 3041 seg0 = segn = NULL; 3042 3043 for (; phdr < phlimit; phdr++) { 3044 switch (phdr->p_type) { 3045 case PT_DYNAMIC: 3046 phdyn = phdr; 3047 break; 3048 case PT_GNU_STACK: 3049 /* Absense of PT_GNU_STACK implies stack_flags == 0. */ 3050 obj->stack_flags = phdr->p_flags; 3051 break; 3052 case PT_LOAD: 3053 if (seg0 == NULL || seg0->p_vaddr > phdr->p_vaddr) 3054 seg0 = phdr; 3055 if (segn == NULL || 3056 segn->p_vaddr + segn->p_memsz < 3057 phdr->p_vaddr + phdr->p_memsz) 3058 segn = phdr; 3059 break; 3060 } 3061 } 3062 3063 obj->mapbase = __DECONST(caddr_t, addr); 3064 obj->mapsize = segn->p_vaddr + segn->p_memsz; 3065 obj->vaddrbase = 0; 3066 obj->relocbase = obj->mapbase; 3067 3068 object_add_name(obj, kname); 3069 obj->path = xstrdup(kname); 3070 obj->dynamic = (const Elf_Dyn *)(obj->relocbase + phdyn->p_vaddr); 3071 3072 if (!digest_dynamic(obj, 0)) { 3073 obj_free(obj); 3074 return (-1); 3075 } 3076 3077 /* 3078 * We assume that kernel-preloaded object does not need 3079 * relocation. It is currently written into read-only page, 3080 * handling relocations would mean we need to allocate at 3081 * least one additional page per AS. 3082 */ 3083 dbg("%s mapbase %p phdrs %p PT_LOAD phdr %p vaddr %p dynamic %p", 3084 obj->path, obj->mapbase, obj->phdr, seg0, 3085 obj->relocbase + seg0->p_vaddr, obj->dynamic); 3086 3087 TAILQ_INSERT_TAIL(&obj_list, obj, next); 3088 obj_count++; 3089 obj_loads++; 3090 linkmap_add(obj); /* for GDB & dlinfo() */ 3091 max_stack_flags |= obj->stack_flags; 3092 3093 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 3094 obj->path); 3095 return (0); 3096 } 3097 3098 Obj_Entry * 3099 obj_from_addr(const void *addr) 3100 { 3101 Obj_Entry *obj; 3102 3103 TAILQ_FOREACH(obj, &obj_list, next) { 3104 if (obj->marker) 3105 continue; 3106 if (addr < (void *)obj->mapbase) 3107 continue; 3108 if (addr < (void *)(obj->mapbase + obj->mapsize)) 3109 return obj; 3110 } 3111 return (NULL); 3112 } 3113 3114 static void 3115 preinit_main(void) 3116 { 3117 uintptr_t *preinit_addr; 3118 int index; 3119 3120 preinit_addr = obj_main->preinit_array; 3121 if (preinit_addr == NULL) 3122 return; 3123 3124 for (index = 0; index < obj_main->preinit_array_num; index++) { 3125 if (preinit_addr[index] != 0 && preinit_addr[index] != 1) { 3126 dbg("calling preinit function for %s at %p", 3127 obj_main->path, (void *)preinit_addr[index]); 3128 LD_UTRACE(UTRACE_INIT_CALL, obj_main, 3129 (void *)preinit_addr[index], 0, 0, obj_main->path); 3130 call_init_pointer(obj_main, preinit_addr[index]); 3131 } 3132 } 3133 } 3134 3135 /* 3136 * Call the finalization functions for each of the objects in "list" 3137 * belonging to the DAG of "root" and referenced once. If NULL "root" 3138 * is specified, every finalization function will be called regardless 3139 * of the reference count and the list elements won't be freed. All of 3140 * the objects are expected to have non-NULL fini functions. 3141 */ 3142 static void 3143 objlist_call_fini(Objlist *list, Obj_Entry *root, RtldLockState *lockstate) 3144 { 3145 Objlist_Entry *elm; 3146 struct dlerror_save *saved_msg; 3147 uintptr_t *fini_addr; 3148 int index; 3149 3150 assert(root == NULL || root->refcount == 1); 3151 3152 if (root != NULL) 3153 root->doomed = true; 3154 3155 /* 3156 * Preserve the current error message since a fini function might 3157 * call into the dynamic linker and overwrite it. 3158 */ 3159 saved_msg = errmsg_save(); 3160 do { 3161 STAILQ_FOREACH(elm, list, link) { 3162 if (root != NULL && 3163 (elm->obj->refcount != 1 || 3164 objlist_find(&root->dagmembers, elm->obj) == 3165 NULL)) 3166 continue; 3167 /* Remove object from fini list to prevent recursive 3168 * invocation. */ 3169 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 3170 /* Ensure that new references cannot be acquired. */ 3171 elm->obj->doomed = true; 3172 3173 hold_object(elm->obj); 3174 lock_release(rtld_bind_lock, lockstate); 3175 /* 3176 * It is legal to have both DT_FINI and DT_FINI_ARRAY 3177 * defined. When this happens, DT_FINI_ARRAY is 3178 * processed first. 3179 */ 3180 fini_addr = elm->obj->fini_array; 3181 if (fini_addr != NULL && elm->obj->fini_array_num > 0) { 3182 for (index = elm->obj->fini_array_num - 1; 3183 index >= 0; index--) { 3184 if (fini_addr[index] != 0 && 3185 fini_addr[index] != 1 && 3186 fini_addr[index] != (Elf_Addr)-1) { 3187 dbg("calling fini function for %s at %p", 3188 elm->obj->path, 3189 (void *)fini_addr[index]); 3190 LD_UTRACE(UTRACE_FINI_CALL, 3191 elm->obj, 3192 (void *)fini_addr[index], 0, 3193 0, elm->obj->path); 3194 call_initfini_pointer(elm->obj, 3195 fini_addr[index]); 3196 } 3197 } 3198 } 3199 if (elm->obj->fini != 0) { 3200 dbg("calling fini function for %s at %p", 3201 elm->obj->path, (void *)elm->obj->fini); 3202 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, 3203 (void *)elm->obj->fini, 0, 0, 3204 elm->obj->path); 3205 call_initfini_pointer(elm->obj, elm->obj->fini); 3206 } 3207 wlock_acquire(rtld_bind_lock, lockstate); 3208 unhold_object(elm->obj); 3209 /* No need to free anything if process is going down. */ 3210 if (root != NULL) 3211 free(elm); 3212 /* 3213 * We must restart the list traversal after every fini 3214 * call because a dlclose() call from the fini function 3215 * or from another thread might have modified the 3216 * reference counts. 3217 */ 3218 break; 3219 } 3220 } while (elm != NULL); 3221 errmsg_restore(saved_msg); 3222 } 3223 3224 /* 3225 * Call the initialization functions for each of the objects in 3226 * "list". All of the objects are expected to have non-NULL init 3227 * functions. 3228 */ 3229 static void 3230 objlist_call_init(Objlist *list, RtldLockState *lockstate) 3231 { 3232 Objlist_Entry *elm; 3233 Obj_Entry *obj; 3234 struct dlerror_save *saved_msg; 3235 uintptr_t *init_addr; 3236 void (*reg)(void (*)(void)); 3237 int index; 3238 3239 /* 3240 * Clean init_scanned flag so that objects can be rechecked and 3241 * possibly initialized earlier if any of vectors called below 3242 * cause the change by using dlopen. 3243 */ 3244 TAILQ_FOREACH(obj, &obj_list, next) { 3245 if (obj->marker) 3246 continue; 3247 obj->init_scanned = false; 3248 } 3249 3250 /* 3251 * Preserve the current error message since an init function might 3252 * call into the dynamic linker and overwrite it. 3253 */ 3254 saved_msg = errmsg_save(); 3255 STAILQ_FOREACH(elm, list, link) { 3256 if (elm->obj->init_done) /* Initialized early. */ 3257 continue; 3258 /* 3259 * Race: other thread might try to use this object before 3260 * current one completes the initialization. Not much can be 3261 * done here without better locking. 3262 */ 3263 elm->obj->init_done = true; 3264 hold_object(elm->obj); 3265 reg = NULL; 3266 if (elm->obj == obj_main && obj_main->crt_no_init) { 3267 reg = (void (*)(void (*)(void))) 3268 get_program_var_addr("__libc_atexit", lockstate); 3269 } 3270 lock_release(rtld_bind_lock, lockstate); 3271 if (reg != NULL) { 3272 reg(rtld_exit); 3273 rtld_exit_ptr = rtld_nop_exit; 3274 } 3275 3276 /* 3277 * It is legal to have both DT_INIT and DT_INIT_ARRAY defined. 3278 * When this happens, DT_INIT is processed first. 3279 */ 3280 if (elm->obj->init != 0) { 3281 dbg("calling init function for %s at %p", 3282 elm->obj->path, (void *)elm->obj->init); 3283 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, 3284 (void *)elm->obj->init, 0, 0, elm->obj->path); 3285 call_init_pointer(elm->obj, elm->obj->init); 3286 } 3287 init_addr = elm->obj->init_array; 3288 if (init_addr != NULL) { 3289 for (index = 0; index < elm->obj->init_array_num; 3290 index++) { 3291 if (init_addr[index] != 0 && 3292 init_addr[index] != 1 && 3293 init_addr[index] != (Elf_Addr)-1) { 3294 dbg("calling init function for %s at %p", 3295 elm->obj->path, 3296 (void *)init_addr[index]); 3297 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, 3298 (void *)init_addr[index], 0, 0, 3299 elm->obj->path); 3300 call_init_pointer(elm->obj, 3301 init_addr[index]); 3302 } 3303 } 3304 } 3305 wlock_acquire(rtld_bind_lock, lockstate); 3306 unhold_object(elm->obj); 3307 } 3308 errmsg_restore(saved_msg); 3309 } 3310 3311 static void 3312 objlist_clear(Objlist *list) 3313 { 3314 Objlist_Entry *elm; 3315 3316 while (!STAILQ_EMPTY(list)) { 3317 elm = STAILQ_FIRST(list); 3318 STAILQ_REMOVE_HEAD(list, link); 3319 free(elm); 3320 } 3321 } 3322 3323 static Objlist_Entry * 3324 objlist_find(Objlist *list, const Obj_Entry *obj) 3325 { 3326 Objlist_Entry *elm; 3327 3328 STAILQ_FOREACH(elm, list, link) 3329 if (elm->obj == obj) 3330 return elm; 3331 return (NULL); 3332 } 3333 3334 static void 3335 objlist_init(Objlist *list) 3336 { 3337 STAILQ_INIT(list); 3338 } 3339 3340 static void 3341 objlist_push_head(Objlist *list, Obj_Entry *obj) 3342 { 3343 Objlist_Entry *elm; 3344 3345 elm = NEW(Objlist_Entry); 3346 elm->obj = obj; 3347 STAILQ_INSERT_HEAD(list, elm, link); 3348 } 3349 3350 static void 3351 objlist_push_tail(Objlist *list, Obj_Entry *obj) 3352 { 3353 Objlist_Entry *elm; 3354 3355 elm = NEW(Objlist_Entry); 3356 elm->obj = obj; 3357 STAILQ_INSERT_TAIL(list, elm, link); 3358 } 3359 3360 static void 3361 objlist_put_after(Objlist *list, Obj_Entry *listobj, Obj_Entry *obj) 3362 { 3363 Objlist_Entry *elm, *listelm; 3364 3365 STAILQ_FOREACH(listelm, list, link) { 3366 if (listelm->obj == listobj) 3367 break; 3368 } 3369 elm = NEW(Objlist_Entry); 3370 elm->obj = obj; 3371 if (listelm != NULL) 3372 STAILQ_INSERT_AFTER(list, listelm, elm, link); 3373 else 3374 STAILQ_INSERT_TAIL(list, elm, link); 3375 } 3376 3377 static void 3378 objlist_remove(Objlist *list, Obj_Entry *obj) 3379 { 3380 Objlist_Entry *elm; 3381 3382 if ((elm = objlist_find(list, obj)) != NULL) { 3383 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 3384 free(elm); 3385 } 3386 } 3387 3388 /* 3389 * Relocate dag rooted in the specified object. 3390 * Returns 0 on success, or -1 on failure. 3391 */ 3392 3393 static int 3394 relocate_object_dag(Obj_Entry *root, bool bind_now, Obj_Entry *rtldobj, 3395 int flags, RtldLockState *lockstate) 3396 { 3397 Objlist_Entry *elm; 3398 int error; 3399 3400 error = 0; 3401 STAILQ_FOREACH(elm, &root->dagmembers, link) { 3402 error = relocate_object(elm->obj, bind_now, rtldobj, flags, 3403 lockstate); 3404 if (error == -1) 3405 break; 3406 } 3407 return (error); 3408 } 3409 3410 /* 3411 * Prepare for, or clean after, relocating an object marked with 3412 * DT_TEXTREL or DF_TEXTREL. Before relocating, all read-only 3413 * segments are remapped read-write. After relocations are done, the 3414 * segment's permissions are returned back to the modes specified in 3415 * the phdrs. If any relocation happened, or always for wired 3416 * program, COW is triggered. 3417 */ 3418 static int 3419 reloc_textrel_prot(Obj_Entry *obj, bool before) 3420 { 3421 const Elf_Phdr *ph; 3422 void *base; 3423 size_t sz; 3424 int prot; 3425 3426 for (ph = obj->phdr; ph < obj->phdr + obj->phnum; ph++) { 3427 if (ph->p_type != PT_LOAD || (ph->p_flags & PF_W) != 0) 3428 continue; 3429 base = obj->relocbase + rtld_trunc_page(ph->p_vaddr); 3430 sz = rtld_round_page(ph->p_vaddr + ph->p_filesz) - 3431 rtld_trunc_page(ph->p_vaddr); 3432 prot = before ? (PROT_READ | PROT_WRITE) : 3433 convert_prot(ph->p_flags); 3434 if (mprotect(base, sz, prot) == -1) { 3435 _rtld_error("%s: Cannot write-%sable text segment: %s", 3436 obj->path, before ? "en" : "dis", 3437 rtld_strerror(errno)); 3438 return (-1); 3439 } 3440 } 3441 return (0); 3442 } 3443 3444 /* Process RELR relative relocations. */ 3445 static void 3446 reloc_relr(Obj_Entry *obj) 3447 { 3448 const Elf_Relr *relr, *relrlim; 3449 Elf_Addr *where; 3450 3451 relrlim = (const Elf_Relr *)((const char *)obj->relr + obj->relrsize); 3452 for (relr = obj->relr; relr < relrlim; relr++) { 3453 Elf_Relr entry = *relr; 3454 3455 if ((entry & 1) == 0) { 3456 where = (Elf_Addr *)(obj->relocbase + entry); 3457 *where++ += (Elf_Addr)obj->relocbase; 3458 } else { 3459 for (long i = 0; (entry >>= 1) != 0; i++) 3460 if ((entry & 1) != 0) 3461 where[i] += (Elf_Addr)obj->relocbase; 3462 where += CHAR_BIT * sizeof(Elf_Relr) - 1; 3463 } 3464 } 3465 } 3466 3467 /* 3468 * Relocate single object. 3469 * Returns 0 on success, or -1 on failure. 3470 */ 3471 static int 3472 relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, int flags, 3473 RtldLockState *lockstate) 3474 { 3475 if (obj->relocated) 3476 return (0); 3477 obj->relocated = true; 3478 if (obj != rtldobj) 3479 dbg("relocating \"%s\"", obj->path); 3480 3481 if (obj->symtab == NULL || obj->strtab == NULL || 3482 !(obj->valid_hash_sysv || obj->valid_hash_gnu)) 3483 dbg("object %s has no run-time symbol table", obj->path); 3484 3485 /* There are relocations to the write-protected text segment. */ 3486 if (obj->textrel && reloc_textrel_prot(obj, true) != 0) 3487 return (-1); 3488 3489 /* Process the non-PLT non-IFUNC relocations. */ 3490 if (reloc_non_plt(obj, rtldobj, flags, lockstate)) 3491 return (-1); 3492 reloc_relr(obj); 3493 3494 /* Re-protected the text segment. */ 3495 if (obj->textrel && reloc_textrel_prot(obj, false) != 0) 3496 return (-1); 3497 3498 /* Set the special PLT or GOT entries. */ 3499 init_pltgot(obj); 3500 3501 /* Process the PLT relocations. */ 3502 if (reloc_plt(obj, flags, lockstate) == -1) 3503 return (-1); 3504 /* Relocate the jump slots if we are doing immediate binding. */ 3505 if ((obj->bind_now || bind_now) && 3506 reloc_jmpslots(obj, flags, lockstate) == -1) 3507 return (-1); 3508 3509 if (obj != rtldobj && !obj->mainprog && obj_enforce_relro(obj) == -1) 3510 return (-1); 3511 3512 /* 3513 * Set up the magic number and version in the Obj_Entry. These 3514 * were checked in the crt1.o from the original ElfKit, so we 3515 * set them for backward compatibility. 3516 */ 3517 obj->magic = RTLD_MAGIC; 3518 obj->version = RTLD_VERSION; 3519 3520 return (0); 3521 } 3522 3523 /* 3524 * Relocate newly-loaded shared objects. The argument is a pointer to 3525 * the Obj_Entry for the first such object. All objects from the first 3526 * to the end of the list of objects are relocated. Returns 0 on success, 3527 * or -1 on failure. 3528 */ 3529 static int 3530 relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj, int flags, 3531 RtldLockState *lockstate) 3532 { 3533 Obj_Entry *obj; 3534 int error; 3535 3536 for (error = 0, obj = first; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 3537 if (obj->marker) 3538 continue; 3539 error = relocate_object(obj, bind_now, rtldobj, flags, 3540 lockstate); 3541 if (error == -1) 3542 break; 3543 } 3544 return (error); 3545 } 3546 3547 /* 3548 * The handling of R_MACHINE_IRELATIVE relocations and jumpslots 3549 * referencing STT_GNU_IFUNC symbols is postponed till the other 3550 * relocations are done. The indirect functions specified as 3551 * ifunc are allowed to call other symbols, so we need to have 3552 * objects relocated before asking for resolution from indirects. 3553 * 3554 * The R_MACHINE_IRELATIVE slots are resolved in greedy fashion, 3555 * instead of the usual lazy handling of PLT slots. It is 3556 * consistent with how GNU does it. 3557 */ 3558 static int 3559 resolve_object_ifunc(Obj_Entry *obj, bool bind_now, int flags, 3560 RtldLockState *lockstate) 3561 { 3562 if (obj->ifuncs_resolved) 3563 return (0); 3564 obj->ifuncs_resolved = true; 3565 if (!obj->irelative && !obj->irelative_nonplt && 3566 !((obj->bind_now || bind_now) && obj->gnu_ifunc) && 3567 !obj->non_plt_gnu_ifunc) 3568 return (0); 3569 if (obj_disable_relro(obj) == -1 || 3570 (obj->irelative && reloc_iresolve(obj, lockstate) == -1) || 3571 (obj->irelative_nonplt && 3572 reloc_iresolve_nonplt(obj, lockstate) == -1) || 3573 ((obj->bind_now || bind_now) && obj->gnu_ifunc && 3574 reloc_gnu_ifunc(obj, flags, lockstate) == -1) || 3575 (obj->non_plt_gnu_ifunc && 3576 reloc_non_plt(obj, &obj_rtld, flags | SYMLOOK_IFUNC, 3577 lockstate) == -1) || 3578 obj_enforce_relro(obj) == -1) 3579 return (-1); 3580 return (0); 3581 } 3582 3583 static int 3584 initlist_objects_ifunc(Objlist *list, bool bind_now, int flags, 3585 RtldLockState *lockstate) 3586 { 3587 Objlist_Entry *elm; 3588 Obj_Entry *obj; 3589 3590 STAILQ_FOREACH(elm, list, link) { 3591 obj = elm->obj; 3592 if (obj->marker) 3593 continue; 3594 if (resolve_object_ifunc(obj, bind_now, flags, lockstate) == -1) 3595 return (-1); 3596 } 3597 return (0); 3598 } 3599 3600 /* 3601 * Cleanup procedure. It will be called (by the atexit mechanism) just 3602 * before the process exits. 3603 */ 3604 static void 3605 rtld_exit(void) 3606 { 3607 RtldLockState lockstate; 3608 3609 wlock_acquire(rtld_bind_lock, &lockstate); 3610 dbg("rtld_exit()"); 3611 objlist_call_fini(&list_fini, NULL, &lockstate); 3612 /* No need to remove the items from the list, since we are exiting. */ 3613 if (!libmap_disable) 3614 lm_fini(); 3615 lock_release(rtld_bind_lock, &lockstate); 3616 } 3617 3618 static void 3619 rtld_nop_exit(void) 3620 { 3621 } 3622 3623 /* 3624 * Parse string of the format '#number/name", where number must be a 3625 * decimal number of the opened file descriptor listed in 3626 * LD_LIBRARY_PATH_FDS. If successful, tries to open dso name under 3627 * dirfd number and returns resulting fd. 3628 * On any error, returns -1. 3629 */ 3630 static int 3631 try_fds_open(const char *name, const char *path) 3632 { 3633 const char *n; 3634 char *envcopy, *fdstr, *last_token, *ncopy; 3635 size_t len; 3636 int fd, dirfd, dirfd_path; 3637 3638 if (!trust || name[0] != '#' || path == NULL) 3639 return (-1); 3640 3641 name++; 3642 n = strchr(name, '/'); 3643 if (n == NULL) 3644 return (-1); 3645 len = n - name; 3646 ncopy = xmalloc(len + 1); 3647 memcpy(ncopy, name, len); 3648 ncopy[len] = '\0'; 3649 dirfd = parse_integer(ncopy); 3650 free(ncopy); 3651 if (dirfd == -1) 3652 return (-1); 3653 3654 envcopy = xstrdup(path); 3655 dirfd_path = -1; 3656 for (fdstr = strtok_r(envcopy, ":", &last_token); fdstr != NULL; 3657 fdstr = strtok_r(NULL, ":", &last_token)) { 3658 dirfd_path = parse_integer(fdstr); 3659 if (dirfd_path == dirfd) 3660 break; 3661 } 3662 free(envcopy); 3663 if (dirfd_path != dirfd) 3664 return (-1); 3665 3666 fd = __sys_openat(dirfd, n + 1, O_RDONLY | O_CLOEXEC | O_VERIFY); 3667 return (fd); 3668 } 3669 3670 /* 3671 * Iterate over a search path, translate each element, and invoke the 3672 * callback on the result. 3673 */ 3674 static void * 3675 path_enumerate(const char *path, path_enum_proc callback, 3676 const char *refobj_path, void *arg) 3677 { 3678 const char *trans; 3679 if (path == NULL) 3680 return (NULL); 3681 3682 path += strspn(path, ":;"); 3683 while (*path != '\0') { 3684 size_t len; 3685 char *res; 3686 3687 len = strcspn(path, ":;"); 3688 trans = lm_findn(refobj_path, path, len); 3689 if (trans) 3690 res = callback(trans, strlen(trans), arg); 3691 else 3692 res = callback(path, len, arg); 3693 3694 if (res != NULL) 3695 return (res); 3696 3697 path += len; 3698 path += strspn(path, ":;"); 3699 } 3700 3701 return (NULL); 3702 } 3703 3704 struct try_library_args { 3705 const char *name; 3706 size_t namelen; 3707 char *buffer; 3708 size_t buflen; 3709 int fd; 3710 }; 3711 3712 static void * 3713 try_library_path(const char *dir, size_t dirlen, void *param) 3714 { 3715 struct try_library_args *arg; 3716 int fd; 3717 3718 arg = param; 3719 if (*dir == '/' || trust) { 3720 char *pathname; 3721 3722 if (dirlen + 1 + arg->namelen + 1 > arg->buflen) 3723 return (NULL); 3724 3725 pathname = arg->buffer; 3726 strncpy(pathname, dir, dirlen); 3727 pathname[dirlen] = '/'; 3728 strcpy(pathname + dirlen + 1, arg->name); 3729 3730 dbg(" Trying \"%s\"", pathname); 3731 fd = open(pathname, O_RDONLY | O_CLOEXEC | O_VERIFY); 3732 if (fd >= 0) { 3733 dbg(" Opened \"%s\", fd %d", pathname, fd); 3734 pathname = xmalloc(dirlen + 1 + arg->namelen + 1); 3735 strcpy(pathname, arg->buffer); 3736 arg->fd = fd; 3737 return (pathname); 3738 } else { 3739 dbg(" Failed to open \"%s\": %s", pathname, 3740 rtld_strerror(errno)); 3741 } 3742 } 3743 return (NULL); 3744 } 3745 3746 static char * 3747 search_library_path(const char *name, const char *path, const char *refobj_path, 3748 int *fdp) 3749 { 3750 char *p; 3751 struct try_library_args arg; 3752 3753 if (path == NULL) 3754 return (NULL); 3755 3756 arg.name = name; 3757 arg.namelen = strlen(name); 3758 arg.buffer = xmalloc(PATH_MAX); 3759 arg.buflen = PATH_MAX; 3760 arg.fd = -1; 3761 3762 p = path_enumerate(path, try_library_path, refobj_path, &arg); 3763 *fdp = arg.fd; 3764 3765 free(arg.buffer); 3766 3767 return (p); 3768 } 3769 3770 /* 3771 * Finds the library with the given name using the directory descriptors 3772 * listed in the LD_LIBRARY_PATH_FDS environment variable. 3773 * 3774 * Returns a freshly-opened close-on-exec file descriptor for the library, 3775 * or -1 if the library cannot be found. 3776 */ 3777 static char * 3778 search_library_pathfds(const char *name, const char *path, int *fdp) 3779 { 3780 char *envcopy, *fdstr, *found, *last_token; 3781 size_t len; 3782 int dirfd, fd; 3783 3784 dbg("%s('%s', '%s', fdp)", __func__, name, path); 3785 3786 /* Don't load from user-specified libdirs into setuid binaries. */ 3787 if (!trust) 3788 return (NULL); 3789 3790 /* We can't do anything if LD_LIBRARY_PATH_FDS isn't set. */ 3791 if (path == NULL) 3792 return (NULL); 3793 3794 /* LD_LIBRARY_PATH_FDS only works with relative paths. */ 3795 if (name[0] == '/') { 3796 dbg("Absolute path (%s) passed to %s", name, __func__); 3797 return (NULL); 3798 } 3799 3800 /* 3801 * Use strtok_r() to walk the FD:FD:FD list. This requires a local 3802 * copy of the path, as strtok_r rewrites separator tokens 3803 * with '\0'. 3804 */ 3805 found = NULL; 3806 envcopy = xstrdup(path); 3807 for (fdstr = strtok_r(envcopy, ":", &last_token); fdstr != NULL; 3808 fdstr = strtok_r(NULL, ":", &last_token)) { 3809 dirfd = parse_integer(fdstr); 3810 if (dirfd < 0) { 3811 _rtld_error("failed to parse directory FD: '%s'", 3812 fdstr); 3813 break; 3814 } 3815 fd = __sys_openat(dirfd, name, O_RDONLY | O_CLOEXEC | O_VERIFY); 3816 if (fd >= 0) { 3817 *fdp = fd; 3818 len = strlen(fdstr) + strlen(name) + 3; 3819 found = xmalloc(len); 3820 if (rtld_snprintf(found, len, "#%d/%s", dirfd, name) < 3821 0) { 3822 _rtld_error("error generating '%d/%s'", dirfd, 3823 name); 3824 rtld_die(); 3825 } 3826 dbg("open('%s') => %d", found, fd); 3827 break; 3828 } 3829 } 3830 free(envcopy); 3831 3832 return (found); 3833 } 3834 3835 int 3836 dlclose(void *handle) 3837 { 3838 RtldLockState lockstate; 3839 int error; 3840 3841 wlock_acquire(rtld_bind_lock, &lockstate); 3842 error = dlclose_locked(handle, &lockstate); 3843 lock_release(rtld_bind_lock, &lockstate); 3844 return (error); 3845 } 3846 3847 static int 3848 dlclose_locked(void *handle, RtldLockState *lockstate) 3849 { 3850 Obj_Entry *root; 3851 3852 root = dlcheck(handle); 3853 if (root == NULL) 3854 return (-1); 3855 LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount, 3856 root->path); 3857 3858 /* Unreference the object and its dependencies. */ 3859 root->dl_refcount--; 3860 3861 if (root->refcount == 1) { 3862 /* 3863 * The object will be no longer referenced, so we must unload 3864 * it. First, call the fini functions. 3865 */ 3866 objlist_call_fini(&list_fini, root, lockstate); 3867 3868 unref_dag(root); 3869 3870 /* Finish cleaning up the newly-unreferenced objects. */ 3871 GDB_STATE(RT_DELETE, &root->linkmap); 3872 unload_object(root, lockstate); 3873 GDB_STATE(RT_CONSISTENT, NULL); 3874 } else 3875 unref_dag(root); 3876 3877 LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL); 3878 return (0); 3879 } 3880 3881 char * 3882 dlerror(void) 3883 { 3884 if (*(lockinfo.dlerror_seen()) != 0) 3885 return (NULL); 3886 *lockinfo.dlerror_seen() = 1; 3887 return (lockinfo.dlerror_loc()); 3888 } 3889 3890 /* 3891 * This function is deprecated and has no effect. 3892 */ 3893 void 3894 dllockinit(void *context, void *(*_lock_create)(void *context)__unused, 3895 void (*_rlock_acquire)(void *lock) __unused, 3896 void (*_wlock_acquire)(void *lock) __unused, 3897 void (*_lock_release)(void *lock) __unused, 3898 void (*_lock_destroy)(void *lock) __unused, 3899 void (*context_destroy)(void *context)) 3900 { 3901 static void *cur_context; 3902 static void (*cur_context_destroy)(void *); 3903 3904 /* Just destroy the context from the previous call, if necessary. */ 3905 if (cur_context_destroy != NULL) 3906 cur_context_destroy(cur_context); 3907 cur_context = context; 3908 cur_context_destroy = context_destroy; 3909 } 3910 3911 void * 3912 dlopen(const char *name, int mode) 3913 { 3914 return (rtld_dlopen(name, -1, mode)); 3915 } 3916 3917 void * 3918 fdlopen(int fd, int mode) 3919 { 3920 return (rtld_dlopen(NULL, fd, mode)); 3921 } 3922 3923 static void * 3924 rtld_dlopen(const char *name, int fd, int mode) 3925 { 3926 RtldLockState lockstate; 3927 int lo_flags; 3928 3929 LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name); 3930 ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1"; 3931 if (ld_tracing != NULL) { 3932 rlock_acquire(rtld_bind_lock, &lockstate); 3933 if (sigsetjmp(lockstate.env, 0) != 0) 3934 lock_upgrade(rtld_bind_lock, &lockstate); 3935 environ = __DECONST(char **, 3936 *get_program_var_addr("environ", &lockstate)); 3937 lock_release(rtld_bind_lock, &lockstate); 3938 } 3939 lo_flags = RTLD_LO_DLOPEN; 3940 if (mode & RTLD_NODELETE) 3941 lo_flags |= RTLD_LO_NODELETE; 3942 if (mode & RTLD_NOLOAD) 3943 lo_flags |= RTLD_LO_NOLOAD; 3944 if (mode & RTLD_DEEPBIND) 3945 lo_flags |= RTLD_LO_DEEPBIND; 3946 if (ld_tracing != NULL) 3947 lo_flags |= RTLD_LO_TRACE | RTLD_LO_IGNSTLS; 3948 3949 return (dlopen_object(name, fd, obj_main, lo_flags, 3950 mode & (RTLD_MODEMASK | RTLD_GLOBAL), NULL)); 3951 } 3952 3953 static void 3954 dlopen_cleanup(Obj_Entry *obj, RtldLockState *lockstate) 3955 { 3956 obj->dl_refcount--; 3957 unref_dag(obj); 3958 if (obj->refcount == 0) 3959 unload_object(obj, lockstate); 3960 } 3961 3962 static Obj_Entry * 3963 dlopen_object(const char *name, int fd, Obj_Entry *refobj, int lo_flags, 3964 int mode, RtldLockState *lockstate) 3965 { 3966 Obj_Entry *obj; 3967 Objlist initlist; 3968 RtldLockState mlockstate; 3969 int result; 3970 3971 dbg( 3972 "dlopen_object name \"%s\" fd %d refobj \"%s\" lo_flags %#x mode %#x", 3973 name != NULL ? name : "<null>", fd, 3974 refobj == NULL ? "<null>" : refobj->path, lo_flags, mode); 3975 objlist_init(&initlist); 3976 3977 if (lockstate == NULL && !(lo_flags & RTLD_LO_EARLY)) { 3978 wlock_acquire(rtld_bind_lock, &mlockstate); 3979 lockstate = &mlockstate; 3980 } 3981 GDB_STATE(RT_ADD, NULL); 3982 3983 obj = NULL; 3984 if (name == NULL && fd == -1) { 3985 obj = obj_main; 3986 obj->refcount++; 3987 } else { 3988 obj = load_object(name, fd, refobj, lo_flags); 3989 } 3990 3991 if (obj != NULL) { 3992 obj->dl_refcount++; 3993 if ((mode & RTLD_GLOBAL) != 0 && 3994 objlist_find(&list_global, obj) == NULL) 3995 objlist_push_tail(&list_global, obj); 3996 3997 if (!obj->init_done) { 3998 /* We loaded something new and have to init something. 3999 */ 4000 if ((lo_flags & RTLD_LO_DEEPBIND) != 0) 4001 obj->deepbind = true; 4002 result = 0; 4003 if ((lo_flags & (RTLD_LO_EARLY | 4004 RTLD_LO_IGNSTLS)) == 0 && 4005 obj->static_tls && !allocate_tls_offset(obj)) { 4006 _rtld_error( 4007 "%s: No space available for static Thread Local Storage", 4008 obj->path); 4009 result = -1; 4010 } 4011 if (result != -1) 4012 result = load_needed_objects(obj, 4013 lo_flags & (RTLD_LO_DLOPEN | RTLD_LO_EARLY | 4014 RTLD_LO_IGNSTLS | RTLD_LO_TRACE)); 4015 init_dag(obj); 4016 ref_dag(obj); 4017 if (result != -1) 4018 result = rtld_verify_versions(&obj->dagmembers); 4019 if (result != -1 && ld_tracing) 4020 goto trace; 4021 if (result == -1 || relocate_object_dag(obj, 4022 (mode & RTLD_MODEMASK) == RTLD_NOW, &obj_rtld, 4023 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 4024 lockstate) == -1) { 4025 dlopen_cleanup(obj, lockstate); 4026 obj = NULL; 4027 } else if ((lo_flags & RTLD_LO_EARLY) != 0) { 4028 /* 4029 * Do not call the init functions for early 4030 * loaded filtees. The image is still not 4031 * initialized enough for them to work. 4032 * 4033 * Our object is found by the global object list 4034 * and will be ordered among all init calls done 4035 * right before transferring control to main. 4036 */ 4037 } else { 4038 /* Make list of init functions to call. */ 4039 initlist_for_loaded_obj(obj, obj, &initlist); 4040 } 4041 /* 4042 * Process all no_delete or global objects here, given 4043 * them own DAGs to prevent their dependencies from 4044 * being unloaded. This has to be done after we have 4045 * loaded all of the dependencies, so that we do not 4046 * miss any. 4047 */ 4048 if (obj != NULL) 4049 process_z(obj); 4050 } else { 4051 /* 4052 * Bump the reference counts for objects on this DAG. If 4053 * this is the first dlopen() call for the object that 4054 * was already loaded as a dependency, initialize the 4055 * dag starting at it. 4056 */ 4057 init_dag(obj); 4058 ref_dag(obj); 4059 4060 if ((lo_flags & RTLD_LO_TRACE) != 0) 4061 goto trace; 4062 } 4063 if (obj != NULL && 4064 ((lo_flags & RTLD_LO_NODELETE) != 0 || obj->z_nodelete) && 4065 !obj->ref_nodel) { 4066 dbg("obj %s nodelete", obj->path); 4067 ref_dag(obj); 4068 obj->z_nodelete = obj->ref_nodel = true; 4069 } 4070 } 4071 4072 LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0, 4073 name); 4074 GDB_STATE(RT_CONSISTENT, obj ? &obj->linkmap : NULL); 4075 4076 if ((lo_flags & RTLD_LO_EARLY) == 0) { 4077 map_stacks_exec(lockstate); 4078 if (obj != NULL) 4079 distribute_static_tls(&initlist); 4080 } 4081 4082 if (initlist_objects_ifunc(&initlist, (mode & RTLD_MODEMASK) == 4083 RTLD_NOW, (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 4084 lockstate) == -1) { 4085 objlist_clear(&initlist); 4086 dlopen_cleanup(obj, lockstate); 4087 if (lockstate == &mlockstate) 4088 lock_release(rtld_bind_lock, lockstate); 4089 return (NULL); 4090 } 4091 4092 if ((lo_flags & RTLD_LO_EARLY) == 0) { 4093 /* Call the init functions. */ 4094 objlist_call_init(&initlist, lockstate); 4095 } 4096 objlist_clear(&initlist); 4097 if (lockstate == &mlockstate) 4098 lock_release(rtld_bind_lock, lockstate); 4099 return (obj); 4100 trace: 4101 trace_loaded_objects(obj, false); 4102 if (lockstate == &mlockstate) 4103 lock_release(rtld_bind_lock, lockstate); 4104 exit(0); 4105 } 4106 4107 static void * 4108 do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve, 4109 int flags) 4110 { 4111 DoneList donelist; 4112 const Obj_Entry *obj, *defobj; 4113 const Elf_Sym *def; 4114 SymLook req; 4115 RtldLockState lockstate; 4116 tls_index ti; 4117 void *sym; 4118 int res; 4119 4120 def = NULL; 4121 defobj = NULL; 4122 symlook_init(&req, name); 4123 req.ventry = ve; 4124 req.flags = flags | SYMLOOK_IN_PLT; 4125 req.lockstate = &lockstate; 4126 4127 LD_UTRACE(UTRACE_DLSYM_START, handle, NULL, 0, 0, name); 4128 rlock_acquire(rtld_bind_lock, &lockstate); 4129 if (sigsetjmp(lockstate.env, 0) != 0) { 4130 lock_upgrade(rtld_bind_lock, &lockstate); 4131 free(req.donelist_mem); 4132 req.donelist_mem = NULL; 4133 } 4134 if (handle == NULL || handle == RTLD_NEXT || handle == RTLD_DEFAULT || 4135 handle == RTLD_SELF) { 4136 if ((obj = obj_from_addr(retaddr)) == NULL) { 4137 _rtld_error("Cannot determine caller's shared object"); 4138 lock_release(rtld_bind_lock, &lockstate); 4139 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 4140 return (NULL); 4141 } 4142 if (handle == NULL) { /* Just the caller's shared object. */ 4143 res = symlook_obj(&req, obj); 4144 if (res == 0) { 4145 def = req.sym_out; 4146 defobj = req.defobj_out; 4147 } 4148 } else if (handle == RTLD_NEXT || /* Objects after caller's */ 4149 handle == RTLD_SELF) { /* ... caller included */ 4150 if (handle == RTLD_NEXT) 4151 obj = globallist_next(obj); 4152 for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 4153 if (obj->marker) 4154 continue; 4155 res = symlook_obj(&req, obj); 4156 if (res == 0) { 4157 if (def == NULL || 4158 (ld_dynamic_weak && 4159 ELF_ST_BIND( 4160 req.sym_out->st_info) != 4161 STB_WEAK)) { 4162 def = req.sym_out; 4163 defobj = req.defobj_out; 4164 if (!ld_dynamic_weak || 4165 ELF_ST_BIND(def->st_info) != 4166 STB_WEAK) 4167 break; 4168 } 4169 } 4170 } 4171 /* 4172 * Search the dynamic linker itself, and possibly 4173 * resolve the symbol from there. This is how the 4174 * application links to dynamic linker services such as 4175 * dlopen. Note that we ignore ld_dynamic_weak == false 4176 * case, always overriding weak symbols by rtld 4177 * definitions. 4178 */ 4179 if (def == NULL || 4180 ELF_ST_BIND(def->st_info) == STB_WEAK) { 4181 res = symlook_obj(&req, &obj_rtld); 4182 if (res == 0) { 4183 def = req.sym_out; 4184 defobj = req.defobj_out; 4185 } 4186 } 4187 } else { 4188 assert(handle == RTLD_DEFAULT); 4189 res = symlook_default(&req, obj); 4190 if (res == 0) { 4191 defobj = req.defobj_out; 4192 def = req.sym_out; 4193 } 4194 } 4195 } else { 4196 if ((obj = dlcheck(handle)) == NULL) { 4197 lock_release(rtld_bind_lock, &lockstate); 4198 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 4199 return (NULL); 4200 } 4201 4202 donelist_init(&donelist, &req); 4203 if (obj->mainprog) { 4204 /* Handle obtained by dlopen(NULL, ...) implies global 4205 * scope. */ 4206 res = symlook_global(&req, &donelist); 4207 if (res == 0) { 4208 def = req.sym_out; 4209 defobj = req.defobj_out; 4210 } 4211 /* 4212 * Search the dynamic linker itself, and possibly 4213 * resolve the symbol from there. This is how the 4214 * application links to dynamic linker services such as 4215 * dlopen. 4216 */ 4217 if (def == NULL || 4218 ELF_ST_BIND(def->st_info) == STB_WEAK) { 4219 res = symlook_obj(&req, &obj_rtld); 4220 if (res == 0) { 4221 def = req.sym_out; 4222 defobj = req.defobj_out; 4223 } 4224 } 4225 } else { 4226 /* Search the whole DAG rooted at the given object. */ 4227 res = symlook_list(&req, &obj->dagmembers, &donelist); 4228 if (res == 0) { 4229 def = req.sym_out; 4230 defobj = req.defobj_out; 4231 } 4232 } 4233 donelist_free(&donelist); 4234 } 4235 4236 if (def != NULL) { 4237 lock_release(rtld_bind_lock, &lockstate); 4238 4239 /* 4240 * The value required by the caller is derived from the value 4241 * of the symbol. this is simply the relocated value of the 4242 * symbol. 4243 */ 4244 if (ELF_ST_TYPE(def->st_info) == STT_FUNC) 4245 sym = make_function_pointer(def, defobj); 4246 else if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 4247 sym = rtld_resolve_ifunc(defobj, def); 4248 else if (ELF_ST_TYPE(def->st_info) == STT_TLS) { 4249 ti.ti_module = defobj->tlsindex; 4250 ti.ti_offset = def->st_value - TLS_DTV_OFFSET; 4251 sym = __tls_get_addr(&ti); 4252 } else 4253 sym = defobj->relocbase + def->st_value; 4254 LD_UTRACE(UTRACE_DLSYM_STOP, handle, sym, 0, 0, name); 4255 return (sym); 4256 } 4257 4258 _rtld_error("Undefined symbol \"%s%s%s\"", name, ve != NULL ? "@" : "", 4259 ve != NULL ? ve->name : ""); 4260 lock_release(rtld_bind_lock, &lockstate); 4261 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 4262 return (NULL); 4263 } 4264 4265 void * 4266 dlsym(void *handle, const char *name) 4267 { 4268 return (do_dlsym(handle, name, __builtin_return_address(0), NULL, 4269 SYMLOOK_DLSYM)); 4270 } 4271 4272 dlfunc_t 4273 dlfunc(void *handle, const char *name) 4274 { 4275 union { 4276 void *d; 4277 dlfunc_t f; 4278 } rv; 4279 4280 rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL, 4281 SYMLOOK_DLSYM); 4282 return (rv.f); 4283 } 4284 4285 void * 4286 dlvsym(void *handle, const char *name, const char *version) 4287 { 4288 Ver_Entry ventry; 4289 4290 ventry.name = version; 4291 ventry.file = NULL; 4292 ventry.hash = elf_hash(version); 4293 ventry.flags = 0; 4294 return (do_dlsym(handle, name, __builtin_return_address(0), &ventry, 4295 SYMLOOK_DLSYM)); 4296 } 4297 4298 int 4299 _rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info) 4300 { 4301 const Obj_Entry *obj; 4302 RtldLockState lockstate; 4303 4304 rlock_acquire(rtld_bind_lock, &lockstate); 4305 obj = obj_from_addr(addr); 4306 if (obj == NULL) { 4307 _rtld_error("No shared object contains address"); 4308 lock_release(rtld_bind_lock, &lockstate); 4309 return (0); 4310 } 4311 rtld_fill_dl_phdr_info(obj, phdr_info); 4312 lock_release(rtld_bind_lock, &lockstate); 4313 return (1); 4314 } 4315 4316 int 4317 dladdr(const void *addr, Dl_info *info) 4318 { 4319 const Obj_Entry *obj; 4320 const Elf_Sym *def; 4321 void *symbol_addr; 4322 unsigned long symoffset; 4323 RtldLockState lockstate; 4324 4325 rlock_acquire(rtld_bind_lock, &lockstate); 4326 obj = obj_from_addr(addr); 4327 if (obj == NULL) { 4328 _rtld_error("No shared object contains address"); 4329 lock_release(rtld_bind_lock, &lockstate); 4330 return (0); 4331 } 4332 info->dli_fname = obj->path; 4333 info->dli_fbase = obj->mapbase; 4334 info->dli_saddr = (void *)0; 4335 info->dli_sname = NULL; 4336 4337 /* 4338 * Walk the symbol list looking for the symbol whose address is 4339 * closest to the address sent in. 4340 */ 4341 for (symoffset = 0; symoffset < obj->dynsymcount; symoffset++) { 4342 def = obj->symtab + symoffset; 4343 4344 /* 4345 * For skip the symbol if st_shndx is either SHN_UNDEF or 4346 * SHN_COMMON. 4347 */ 4348 if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON) 4349 continue; 4350 4351 /* 4352 * If the symbol is greater than the specified address, or if it 4353 * is further away from addr than the current nearest symbol, 4354 * then reject it. 4355 */ 4356 symbol_addr = obj->relocbase + def->st_value; 4357 if (symbol_addr > addr || symbol_addr < info->dli_saddr) 4358 continue; 4359 4360 /* Update our idea of the nearest symbol. */ 4361 info->dli_sname = obj->strtab + def->st_name; 4362 info->dli_saddr = symbol_addr; 4363 4364 /* Exact match? */ 4365 if (info->dli_saddr == addr) 4366 break; 4367 } 4368 lock_release(rtld_bind_lock, &lockstate); 4369 return (1); 4370 } 4371 4372 int 4373 dlinfo(void *handle, int request, void *p) 4374 { 4375 const Obj_Entry *obj; 4376 RtldLockState lockstate; 4377 int error; 4378 4379 rlock_acquire(rtld_bind_lock, &lockstate); 4380 4381 if (handle == NULL || handle == RTLD_SELF) { 4382 void *retaddr; 4383 4384 retaddr = __builtin_return_address(0); /* __GNUC__ only */ 4385 if ((obj = obj_from_addr(retaddr)) == NULL) 4386 _rtld_error("Cannot determine caller's shared object"); 4387 } else 4388 obj = dlcheck(handle); 4389 4390 if (obj == NULL) { 4391 lock_release(rtld_bind_lock, &lockstate); 4392 return (-1); 4393 } 4394 4395 error = 0; 4396 switch (request) { 4397 case RTLD_DI_LINKMAP: 4398 *((struct link_map const **)p) = &obj->linkmap; 4399 break; 4400 case RTLD_DI_ORIGIN: 4401 error = rtld_dirname(obj->path, p); 4402 break; 4403 4404 case RTLD_DI_SERINFOSIZE: 4405 case RTLD_DI_SERINFO: 4406 error = do_search_info(obj, request, (struct dl_serinfo *)p); 4407 break; 4408 4409 default: 4410 _rtld_error("Invalid request %d passed to dlinfo()", request); 4411 error = -1; 4412 } 4413 4414 lock_release(rtld_bind_lock, &lockstate); 4415 4416 return (error); 4417 } 4418 4419 static void 4420 rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info) 4421 { 4422 phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase; 4423 phdr_info->dlpi_name = obj->path; 4424 phdr_info->dlpi_phdr = obj->phdr; 4425 phdr_info->dlpi_phnum = obj->phnum; 4426 phdr_info->dlpi_tls_modid = obj->tlsindex; 4427 phdr_info->dlpi_tls_data = (char *)tls_get_addr_slow(_tcb_get(), 4428 obj->tlsindex, 0, true); 4429 phdr_info->dlpi_adds = obj_loads; 4430 phdr_info->dlpi_subs = obj_loads - obj_count; 4431 } 4432 4433 /* 4434 * It's completely UB to actually use this, so extreme caution is advised. It's 4435 * probably not what you want. 4436 */ 4437 int 4438 _dl_iterate_phdr_locked(__dl_iterate_hdr_callback callback, void *param) 4439 { 4440 struct dl_phdr_info phdr_info; 4441 Obj_Entry *obj; 4442 int error; 4443 4444 for (obj = globallist_curr(TAILQ_FIRST(&obj_list)); obj != NULL; 4445 obj = globallist_next(obj)) { 4446 rtld_fill_dl_phdr_info(obj, &phdr_info); 4447 error = callback(&phdr_info, sizeof(phdr_info), param); 4448 if (error != 0) 4449 return (error); 4450 } 4451 4452 rtld_fill_dl_phdr_info(&obj_rtld, &phdr_info); 4453 return (callback(&phdr_info, sizeof(phdr_info), param)); 4454 } 4455 4456 int 4457 dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param) 4458 { 4459 struct dl_phdr_info phdr_info; 4460 Obj_Entry *obj, marker; 4461 RtldLockState bind_lockstate, phdr_lockstate; 4462 int error; 4463 4464 init_marker(&marker); 4465 error = 0; 4466 4467 wlock_acquire(rtld_phdr_lock, &phdr_lockstate); 4468 wlock_acquire(rtld_bind_lock, &bind_lockstate); 4469 for (obj = globallist_curr(TAILQ_FIRST(&obj_list)); obj != NULL;) { 4470 TAILQ_INSERT_AFTER(&obj_list, obj, &marker, next); 4471 rtld_fill_dl_phdr_info(obj, &phdr_info); 4472 hold_object(obj); 4473 lock_release(rtld_bind_lock, &bind_lockstate); 4474 4475 error = callback(&phdr_info, sizeof phdr_info, param); 4476 4477 wlock_acquire(rtld_bind_lock, &bind_lockstate); 4478 unhold_object(obj); 4479 obj = globallist_next(&marker); 4480 TAILQ_REMOVE(&obj_list, &marker, next); 4481 if (error != 0) { 4482 lock_release(rtld_bind_lock, &bind_lockstate); 4483 lock_release(rtld_phdr_lock, &phdr_lockstate); 4484 return (error); 4485 } 4486 } 4487 4488 if (error == 0) { 4489 rtld_fill_dl_phdr_info(&obj_rtld, &phdr_info); 4490 lock_release(rtld_bind_lock, &bind_lockstate); 4491 error = callback(&phdr_info, sizeof(phdr_info), param); 4492 } 4493 lock_release(rtld_phdr_lock, &phdr_lockstate); 4494 return (error); 4495 } 4496 4497 static void * 4498 fill_search_info(const char *dir, size_t dirlen, void *param) 4499 { 4500 struct fill_search_info_args *arg; 4501 4502 arg = param; 4503 4504 if (arg->request == RTLD_DI_SERINFOSIZE) { 4505 arg->serinfo->dls_cnt++; 4506 arg->serinfo->dls_size += sizeof(struct dl_serpath) + dirlen + 4507 1; 4508 } else { 4509 struct dl_serpath *s_entry; 4510 4511 s_entry = arg->serpath; 4512 s_entry->dls_name = arg->strspace; 4513 s_entry->dls_flags = arg->flags; 4514 4515 strncpy(arg->strspace, dir, dirlen); 4516 arg->strspace[dirlen] = '\0'; 4517 4518 arg->strspace += dirlen + 1; 4519 arg->serpath++; 4520 } 4521 4522 return (NULL); 4523 } 4524 4525 static int 4526 do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info) 4527 { 4528 struct dl_serinfo _info; 4529 struct fill_search_info_args args; 4530 4531 args.request = RTLD_DI_SERINFOSIZE; 4532 args.serinfo = &_info; 4533 4534 _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 4535 _info.dls_cnt = 0; 4536 4537 path_enumerate(obj->rpath, fill_search_info, NULL, &args); 4538 path_enumerate(ld_library_path, fill_search_info, NULL, &args); 4539 path_enumerate(obj->runpath, fill_search_info, NULL, &args); 4540 path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, 4541 &args); 4542 if (!obj->z_nodeflib) 4543 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 4544 &args); 4545 4546 if (request == RTLD_DI_SERINFOSIZE) { 4547 info->dls_size = _info.dls_size; 4548 info->dls_cnt = _info.dls_cnt; 4549 return (0); 4550 } 4551 4552 if (info->dls_cnt != _info.dls_cnt || 4553 info->dls_size != _info.dls_size) { 4554 _rtld_error( 4555 "Uninitialized Dl_serinfo struct passed to dlinfo()"); 4556 return (-1); 4557 } 4558 4559 args.request = RTLD_DI_SERINFO; 4560 args.serinfo = info; 4561 args.serpath = &info->dls_serpath[0]; 4562 args.strspace = (char *)&info->dls_serpath[_info.dls_cnt]; 4563 4564 args.flags = LA_SER_RUNPATH; 4565 if (path_enumerate(obj->rpath, fill_search_info, NULL, &args) != NULL) 4566 return (-1); 4567 4568 args.flags = LA_SER_LIBPATH; 4569 if (path_enumerate(ld_library_path, fill_search_info, NULL, &args) != 4570 NULL) 4571 return (-1); 4572 4573 args.flags = LA_SER_RUNPATH; 4574 if (path_enumerate(obj->runpath, fill_search_info, NULL, &args) != NULL) 4575 return (-1); 4576 4577 args.flags = LA_SER_CONFIG; 4578 if (path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, 4579 &args) != NULL) 4580 return (-1); 4581 4582 args.flags = LA_SER_DEFAULT; 4583 if (!obj->z_nodeflib && 4584 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 4585 &args) != NULL) 4586 return (-1); 4587 return (0); 4588 } 4589 4590 static int 4591 rtld_dirname(const char *path, char *bname) 4592 { 4593 const char *endp; 4594 4595 /* Empty or NULL string gets treated as "." */ 4596 if (path == NULL || *path == '\0') { 4597 bname[0] = '.'; 4598 bname[1] = '\0'; 4599 return (0); 4600 } 4601 4602 /* Strip trailing slashes */ 4603 endp = path + strlen(path) - 1; 4604 while (endp > path && *endp == '/') 4605 endp--; 4606 4607 /* Find the start of the dir */ 4608 while (endp > path && *endp != '/') 4609 endp--; 4610 4611 /* Either the dir is "/" or there are no slashes */ 4612 if (endp == path) { 4613 bname[0] = *endp == '/' ? '/' : '.'; 4614 bname[1] = '\0'; 4615 return (0); 4616 } else { 4617 do { 4618 endp--; 4619 } while (endp > path && *endp == '/'); 4620 } 4621 4622 if (endp - path + 2 > PATH_MAX) { 4623 _rtld_error("Filename is too long: %s", path); 4624 return (-1); 4625 } 4626 4627 strncpy(bname, path, endp - path + 1); 4628 bname[endp - path + 1] = '\0'; 4629 return (0); 4630 } 4631 4632 static int 4633 rtld_dirname_abs(const char *path, char *base) 4634 { 4635 char *last; 4636 4637 if (realpath(path, base) == NULL) { 4638 _rtld_error("realpath \"%s\" failed (%s)", path, 4639 rtld_strerror(errno)); 4640 return (-1); 4641 } 4642 dbg("%s -> %s", path, base); 4643 last = strrchr(base, '/'); 4644 if (last == NULL) { 4645 _rtld_error("non-abs result from realpath \"%s\"", path); 4646 return (-1); 4647 } 4648 if (last != base) 4649 *last = '\0'; 4650 return (0); 4651 } 4652 4653 static void 4654 linkmap_add(Obj_Entry *obj) 4655 { 4656 struct link_map *l, *prev; 4657 4658 l = &obj->linkmap; 4659 l->l_name = obj->path; 4660 l->l_base = obj->mapbase; 4661 l->l_ld = obj->dynamic; 4662 l->l_addr = obj->relocbase; 4663 4664 if (r_debug.r_map == NULL) { 4665 r_debug.r_map = l; 4666 return; 4667 } 4668 4669 /* 4670 * Scan to the end of the list, but not past the entry for the 4671 * dynamic linker, which we want to keep at the very end. 4672 */ 4673 for (prev = r_debug.r_map; 4674 prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap; 4675 prev = prev->l_next) 4676 ; 4677 4678 /* Link in the new entry. */ 4679 l->l_prev = prev; 4680 l->l_next = prev->l_next; 4681 if (l->l_next != NULL) 4682 l->l_next->l_prev = l; 4683 prev->l_next = l; 4684 } 4685 4686 static void 4687 linkmap_delete(Obj_Entry *obj) 4688 { 4689 struct link_map *l; 4690 4691 l = &obj->linkmap; 4692 if (l->l_prev == NULL) { 4693 if ((r_debug.r_map = l->l_next) != NULL) 4694 l->l_next->l_prev = NULL; 4695 return; 4696 } 4697 4698 if ((l->l_prev->l_next = l->l_next) != NULL) 4699 l->l_next->l_prev = l->l_prev; 4700 } 4701 4702 /* 4703 * Function for the debugger to set a breakpoint on to gain control. 4704 * 4705 * The two parameters allow the debugger to easily find and determine 4706 * what the runtime loader is doing and to whom it is doing it. 4707 * 4708 * When the loadhook trap is hit (r_debug_state, set at program 4709 * initialization), the arguments can be found on the stack: 4710 * 4711 * +8 struct link_map *m 4712 * +4 struct r_debug *rd 4713 * +0 RetAddr 4714 */ 4715 void 4716 r_debug_state(struct r_debug *rd __unused, struct link_map *m __unused) 4717 { 4718 /* 4719 * The following is a hack to force the compiler to emit calls to 4720 * this function, even when optimizing. If the function is empty, 4721 * the compiler is not obliged to emit any code for calls to it, 4722 * even when marked __noinline. However, gdb depends on those 4723 * calls being made. 4724 */ 4725 __compiler_membar(); 4726 } 4727 4728 /* 4729 * A function called after init routines have completed. This can be used to 4730 * break before a program's entry routine is called, and can be used when 4731 * main is not available in the symbol table. 4732 */ 4733 void 4734 _r_debug_postinit(struct link_map *m __unused) 4735 { 4736 /* See r_debug_state(). */ 4737 __compiler_membar(); 4738 } 4739 4740 static void 4741 release_object(Obj_Entry *obj) 4742 { 4743 if (obj->holdcount > 0) { 4744 obj->unholdfree = true; 4745 return; 4746 } 4747 munmap(obj->mapbase, obj->mapsize); 4748 linkmap_delete(obj); 4749 obj_free(obj); 4750 } 4751 4752 /* 4753 * Get address of the pointer variable in the main program. 4754 * Prefer non-weak symbol over the weak one. 4755 */ 4756 static const void ** 4757 get_program_var_addr(const char *name, RtldLockState *lockstate) 4758 { 4759 SymLook req; 4760 DoneList donelist; 4761 const void **res; 4762 4763 symlook_init(&req, name); 4764 req.lockstate = lockstate; 4765 donelist_init(&donelist, NULL); 4766 if (symlook_global(&req, &donelist) != 0) 4767 return (NULL); 4768 if (ELF_ST_TYPE(req.sym_out->st_info) == STT_FUNC) 4769 res = (const void **)make_function_pointer(req.sym_out, 4770 req.defobj_out); 4771 else if (ELF_ST_TYPE(req.sym_out->st_info) == STT_GNU_IFUNC) 4772 res = (const void **)rtld_resolve_ifunc(req.defobj_out, 4773 req.sym_out); 4774 else 4775 res = (const void **)(req.defobj_out->relocbase + 4776 req.sym_out->st_value); 4777 donelist_free(&donelist); 4778 return (res); 4779 } 4780 4781 /* 4782 * Set a pointer variable in the main program to the given value. This 4783 * is used to set key variables such as "environ" before any of the 4784 * init functions are called. 4785 */ 4786 static void 4787 set_program_var(const char *name, const void *value) 4788 { 4789 const void **addr; 4790 4791 if ((addr = get_program_var_addr(name, NULL)) != NULL) { 4792 dbg("\"%s\": *%p <-- %p", name, addr, value); 4793 *addr = value; 4794 } 4795 } 4796 4797 /* 4798 * Search the global objects, including dependencies and main object, 4799 * for the given symbol. 4800 */ 4801 static int 4802 symlook_global(SymLook *req, DoneList *donelist) 4803 { 4804 SymLook req1; 4805 const Objlist_Entry *elm; 4806 int res; 4807 4808 symlook_init_from_req(&req1, req); 4809 4810 /* Search all objects loaded at program start up. */ 4811 if (req->defobj_out == NULL || (ld_dynamic_weak && 4812 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK)) { 4813 res = symlook_list(&req1, &list_main, donelist); 4814 if (res == 0 && (!ld_dynamic_weak || req->defobj_out == NULL || 4815 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4816 req->sym_out = req1.sym_out; 4817 req->defobj_out = req1.defobj_out; 4818 assert(req->defobj_out != NULL); 4819 } 4820 } 4821 4822 /* Search all DAGs whose roots are RTLD_GLOBAL objects. */ 4823 STAILQ_FOREACH(elm, &list_global, link) { 4824 if (req->defobj_out != NULL && (!ld_dynamic_weak || 4825 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK)) 4826 break; 4827 res = symlook_list(&req1, &elm->obj->dagmembers, donelist); 4828 if (res == 0 && (req->defobj_out == NULL || 4829 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4830 req->sym_out = req1.sym_out; 4831 req->defobj_out = req1.defobj_out; 4832 assert(req->defobj_out != NULL); 4833 } 4834 } 4835 4836 return (req->sym_out != NULL ? 0 : ESRCH); 4837 } 4838 4839 /* 4840 * Given a symbol name in a referencing object, find the corresponding 4841 * definition of the symbol. Returns a pointer to the symbol, or NULL if 4842 * no definition was found. Returns a pointer to the Obj_Entry of the 4843 * defining object via the reference parameter DEFOBJ_OUT. 4844 */ 4845 static int 4846 symlook_default(SymLook *req, const Obj_Entry *refobj) 4847 { 4848 DoneList donelist; 4849 const Objlist_Entry *elm; 4850 SymLook req1; 4851 int res; 4852 4853 donelist_init(&donelist, req); 4854 symlook_init_from_req(&req1, req); 4855 4856 /* 4857 * Look first in the referencing object if linked symbolically, 4858 * and similarly handle protected symbols. 4859 */ 4860 res = symlook_obj(&req1, refobj); 4861 if (res == 0 && (refobj->symbolic || 4862 ELF_ST_VISIBILITY(req1.sym_out->st_other) == STV_PROTECTED || 4863 refobj->deepbind)) { 4864 req->sym_out = req1.sym_out; 4865 req->defobj_out = req1.defobj_out; 4866 assert(req->defobj_out != NULL); 4867 } 4868 if (refobj->symbolic || req->defobj_out != NULL || refobj->deepbind) 4869 donelist_check(&donelist, refobj); 4870 4871 if (!refobj->deepbind) 4872 symlook_global(req, &donelist); 4873 4874 /* Search all dlopened DAGs containing the referencing object. */ 4875 STAILQ_FOREACH(elm, &refobj->dldags, link) { 4876 if (req->sym_out != NULL && (!ld_dynamic_weak || 4877 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK)) 4878 break; 4879 res = symlook_list(&req1, &elm->obj->dagmembers, &donelist); 4880 if (res == 0 && (req->sym_out == NULL || 4881 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4882 req->sym_out = req1.sym_out; 4883 req->defobj_out = req1.defobj_out; 4884 assert(req->defobj_out != NULL); 4885 } 4886 } 4887 4888 if (refobj->deepbind) 4889 symlook_global(req, &donelist); 4890 4891 /* 4892 * Search the dynamic linker itself, and possibly resolve the 4893 * symbol from there. This is how the application links to 4894 * dynamic linker services such as dlopen. 4895 */ 4896 if (req->sym_out == NULL || 4897 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 4898 res = symlook_obj(&req1, &obj_rtld); 4899 if (res == 0) { 4900 req->sym_out = req1.sym_out; 4901 req->defobj_out = req1.defobj_out; 4902 assert(req->defobj_out != NULL); 4903 } 4904 } 4905 4906 donelist_free(&donelist); 4907 return (req->sym_out != NULL ? 0 : ESRCH); 4908 } 4909 4910 static int 4911 symlook_list(SymLook *req, const Objlist *objlist, DoneList *dlp) 4912 { 4913 const Elf_Sym *def; 4914 const Obj_Entry *defobj; 4915 const Objlist_Entry *elm; 4916 SymLook req1; 4917 int res; 4918 4919 def = NULL; 4920 defobj = NULL; 4921 STAILQ_FOREACH(elm, objlist, link) { 4922 if (donelist_check(dlp, elm->obj)) 4923 continue; 4924 symlook_init_from_req(&req1, req); 4925 if ((res = symlook_obj(&req1, elm->obj)) == 0) { 4926 if (def == NULL || (ld_dynamic_weak && 4927 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4928 def = req1.sym_out; 4929 defobj = req1.defobj_out; 4930 if (!ld_dynamic_weak || 4931 ELF_ST_BIND(def->st_info) != STB_WEAK) 4932 break; 4933 } 4934 } 4935 } 4936 if (def != NULL) { 4937 req->sym_out = def; 4938 req->defobj_out = defobj; 4939 return (0); 4940 } 4941 return (ESRCH); 4942 } 4943 4944 /* 4945 * Search the chain of DAGS cointed to by the given Needed_Entry 4946 * for a symbol of the given name. Each DAG is scanned completely 4947 * before advancing to the next one. Returns a pointer to the symbol, 4948 * or NULL if no definition was found. 4949 */ 4950 static int 4951 symlook_needed(SymLook *req, const Needed_Entry *needed, DoneList *dlp) 4952 { 4953 const Elf_Sym *def; 4954 const Needed_Entry *n; 4955 const Obj_Entry *defobj; 4956 SymLook req1; 4957 int res; 4958 4959 def = NULL; 4960 defobj = NULL; 4961 symlook_init_from_req(&req1, req); 4962 for (n = needed; n != NULL; n = n->next) { 4963 if (n->obj == NULL || (res = symlook_list(&req1, 4964 &n->obj->dagmembers, dlp)) != 0) 4965 continue; 4966 if (def == NULL || (ld_dynamic_weak && 4967 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4968 def = req1.sym_out; 4969 defobj = req1.defobj_out; 4970 if (!ld_dynamic_weak || 4971 ELF_ST_BIND(def->st_info) != STB_WEAK) 4972 break; 4973 } 4974 } 4975 if (def != NULL) { 4976 req->sym_out = def; 4977 req->defobj_out = defobj; 4978 return (0); 4979 } 4980 return (ESRCH); 4981 } 4982 4983 static int 4984 symlook_obj_load_filtees(SymLook *req, SymLook *req1, const Obj_Entry *obj, 4985 Needed_Entry *needed) 4986 { 4987 DoneList donelist; 4988 int flags, res; 4989 4990 flags = (req->flags & SYMLOOK_EARLY) != 0 ? RTLD_LO_EARLY : 0; 4991 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 4992 donelist_init(&donelist, NULL); 4993 symlook_init_from_req(req1, req); 4994 res = symlook_needed(req1, needed, &donelist); 4995 donelist_free(&donelist); 4996 return (res); 4997 } 4998 4999 /* 5000 * Search the symbol table of a single shared object for a symbol of 5001 * the given name and version, if requested. Returns a pointer to the 5002 * symbol, or NULL if no definition was found. If the object is 5003 * filter, return filtered symbol from filtee. 5004 * 5005 * The symbol's hash value is passed in for efficiency reasons; that 5006 * eliminates many recomputations of the hash value. 5007 */ 5008 int 5009 symlook_obj(SymLook *req, const Obj_Entry *obj) 5010 { 5011 SymLook req1; 5012 int res, mres; 5013 5014 /* 5015 * If there is at least one valid hash at this point, we prefer to 5016 * use the faster GNU version if available. 5017 */ 5018 if (obj->valid_hash_gnu) 5019 mres = symlook_obj1_gnu(req, obj); 5020 else if (obj->valid_hash_sysv) 5021 mres = symlook_obj1_sysv(req, obj); 5022 else 5023 return (EINVAL); 5024 5025 if (mres == 0) { 5026 if (obj->needed_filtees != NULL) { 5027 res = symlook_obj_load_filtees(req, &req1, obj, 5028 obj->needed_filtees); 5029 if (res == 0) { 5030 req->sym_out = req1.sym_out; 5031 req->defobj_out = req1.defobj_out; 5032 } 5033 return (res); 5034 } 5035 if (obj->needed_aux_filtees != NULL) { 5036 res = symlook_obj_load_filtees(req, &req1, obj, 5037 obj->needed_aux_filtees); 5038 if (res == 0) { 5039 req->sym_out = req1.sym_out; 5040 req->defobj_out = req1.defobj_out; 5041 return (res); 5042 } 5043 } 5044 } 5045 return (mres); 5046 } 5047 5048 /* Symbol match routine common to both hash functions */ 5049 static bool 5050 matched_symbol(SymLook *req, const Obj_Entry *obj, Sym_Match_Result *result, 5051 const unsigned long symnum) 5052 { 5053 Elf_Versym verndx; 5054 const Elf_Sym *symp; 5055 const char *strp; 5056 5057 symp = obj->symtab + symnum; 5058 strp = obj->strtab + symp->st_name; 5059 5060 switch (ELF_ST_TYPE(symp->st_info)) { 5061 case STT_FUNC: 5062 case STT_NOTYPE: 5063 case STT_OBJECT: 5064 case STT_COMMON: 5065 case STT_GNU_IFUNC: 5066 if (symp->st_value == 0) 5067 return (false); 5068 /* fallthrough */ 5069 case STT_TLS: 5070 if (symp->st_shndx != SHN_UNDEF) 5071 break; 5072 else if (((req->flags & SYMLOOK_IN_PLT) == 0) && 5073 (ELF_ST_TYPE(symp->st_info) == STT_FUNC)) 5074 break; 5075 /* fallthrough */ 5076 default: 5077 return (false); 5078 } 5079 if (req->name[0] != strp[0] || strcmp(req->name, strp) != 0) 5080 return (false); 5081 5082 if (req->ventry == NULL) { 5083 if (obj->versyms != NULL) { 5084 verndx = VER_NDX(obj->versyms[symnum]); 5085 if (verndx > obj->vernum) { 5086 _rtld_error( 5087 "%s: symbol %s references wrong version %d", 5088 obj->path, obj->strtab + symnum, verndx); 5089 return (false); 5090 } 5091 /* 5092 * If we are not called from dlsym (i.e. this 5093 * is a normal relocation from unversioned 5094 * binary), accept the symbol immediately if 5095 * it happens to have first version after this 5096 * shared object became versioned. Otherwise, 5097 * if symbol is versioned and not hidden, 5098 * remember it. If it is the only symbol with 5099 * this name exported by the shared object, it 5100 * will be returned as a match by the calling 5101 * function. If symbol is global (verndx < 2) 5102 * accept it unconditionally. 5103 */ 5104 if ((req->flags & SYMLOOK_DLSYM) == 0 && 5105 verndx == VER_NDX_GIVEN) { 5106 result->sym_out = symp; 5107 return (true); 5108 } else if (verndx >= VER_NDX_GIVEN) { 5109 if ((obj->versyms[symnum] & VER_NDX_HIDDEN) == 5110 0) { 5111 if (result->vsymp == NULL) 5112 result->vsymp = symp; 5113 result->vcount++; 5114 } 5115 return (false); 5116 } 5117 } 5118 result->sym_out = symp; 5119 return (true); 5120 } 5121 if (obj->versyms == NULL) { 5122 if (object_match_name(obj, req->ventry->name)) { 5123 _rtld_error( 5124 "%s: object %s should provide version %s for symbol %s", 5125 obj_rtld.path, obj->path, req->ventry->name, 5126 obj->strtab + symnum); 5127 return (false); 5128 } 5129 } else { 5130 verndx = VER_NDX(obj->versyms[symnum]); 5131 if (verndx > obj->vernum) { 5132 _rtld_error("%s: symbol %s references wrong version %d", 5133 obj->path, obj->strtab + symnum, verndx); 5134 return (false); 5135 } 5136 if (obj->vertab[verndx].hash != req->ventry->hash || 5137 strcmp(obj->vertab[verndx].name, req->ventry->name)) { 5138 /* 5139 * Version does not match. Look if this is a 5140 * global symbol and if it is not hidden. If 5141 * global symbol (verndx < 2) is available, 5142 * use it. Do not return symbol if we are 5143 * called by dlvsym, because dlvsym looks for 5144 * a specific version and default one is not 5145 * what dlvsym wants. 5146 */ 5147 if ((req->flags & SYMLOOK_DLSYM) || 5148 (verndx >= VER_NDX_GIVEN) || 5149 (obj->versyms[symnum] & VER_NDX_HIDDEN)) 5150 return (false); 5151 } 5152 } 5153 result->sym_out = symp; 5154 return (true); 5155 } 5156 5157 /* 5158 * Search for symbol using SysV hash function. 5159 * obj->buckets is known not to be NULL at this point; the test for this was 5160 * performed with the obj->valid_hash_sysv assignment. 5161 */ 5162 static int 5163 symlook_obj1_sysv(SymLook *req, const Obj_Entry *obj) 5164 { 5165 unsigned long symnum; 5166 Sym_Match_Result matchres; 5167 5168 matchres.sym_out = NULL; 5169 matchres.vsymp = NULL; 5170 matchres.vcount = 0; 5171 5172 for (symnum = obj->buckets[req->hash % obj->nbuckets]; 5173 symnum != STN_UNDEF; symnum = obj->chains[symnum]) { 5174 if (symnum >= obj->nchains) 5175 return (ESRCH); /* Bad object */ 5176 5177 if (matched_symbol(req, obj, &matchres, symnum)) { 5178 req->sym_out = matchres.sym_out; 5179 req->defobj_out = obj; 5180 return (0); 5181 } 5182 } 5183 if (matchres.vcount == 1) { 5184 req->sym_out = matchres.vsymp; 5185 req->defobj_out = obj; 5186 return (0); 5187 } 5188 return (ESRCH); 5189 } 5190 5191 /* Search for symbol using GNU hash function */ 5192 static int 5193 symlook_obj1_gnu(SymLook *req, const Obj_Entry *obj) 5194 { 5195 Elf_Addr bloom_word; 5196 const Elf32_Word *hashval; 5197 Elf32_Word bucket; 5198 Sym_Match_Result matchres; 5199 unsigned int h1, h2; 5200 unsigned long symnum; 5201 5202 matchres.sym_out = NULL; 5203 matchres.vsymp = NULL; 5204 matchres.vcount = 0; 5205 5206 /* Pick right bitmask word from Bloom filter array */ 5207 bloom_word = obj->bloom_gnu[(req->hash_gnu / __ELF_WORD_SIZE) & 5208 obj->maskwords_bm_gnu]; 5209 5210 /* Calculate modulus word size of gnu hash and its derivative */ 5211 h1 = req->hash_gnu & (__ELF_WORD_SIZE - 1); 5212 h2 = ((req->hash_gnu >> obj->shift2_gnu) & (__ELF_WORD_SIZE - 1)); 5213 5214 /* Filter out the "definitely not in set" queries */ 5215 if (((bloom_word >> h1) & (bloom_word >> h2) & 1) == 0) 5216 return (ESRCH); 5217 5218 /* Locate hash chain and corresponding value element*/ 5219 bucket = obj->buckets_gnu[req->hash_gnu % obj->nbuckets_gnu]; 5220 if (bucket == 0) 5221 return (ESRCH); 5222 hashval = &obj->chain_zero_gnu[bucket]; 5223 do { 5224 if (((*hashval ^ req->hash_gnu) >> 1) == 0) { 5225 symnum = hashval - obj->chain_zero_gnu; 5226 if (matched_symbol(req, obj, &matchres, symnum)) { 5227 req->sym_out = matchres.sym_out; 5228 req->defobj_out = obj; 5229 return (0); 5230 } 5231 } 5232 } while ((*hashval++ & 1) == 0); 5233 if (matchres.vcount == 1) { 5234 req->sym_out = matchres.vsymp; 5235 req->defobj_out = obj; 5236 return (0); 5237 } 5238 return (ESRCH); 5239 } 5240 5241 static void 5242 trace_calc_fmts(const char **main_local, const char **fmt1, const char **fmt2) 5243 { 5244 *main_local = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_PROGNAME); 5245 if (*main_local == NULL) 5246 *main_local = ""; 5247 5248 *fmt1 = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_FMT1); 5249 if (*fmt1 == NULL) 5250 *fmt1 = "\t%o => %p (%x)\n"; 5251 5252 *fmt2 = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_FMT2); 5253 if (*fmt2 == NULL) 5254 *fmt2 = "\t%o (%x)\n"; 5255 } 5256 5257 static void 5258 trace_print_obj(Obj_Entry *obj, const char *name, const char *path, 5259 const char *main_local, const char *fmt1, const char *fmt2) 5260 { 5261 const char *fmt; 5262 int c; 5263 5264 if (fmt1 == NULL) 5265 fmt = fmt2; 5266 else 5267 /* XXX bogus */ 5268 fmt = strncmp(name, "lib", 3) == 0 ? fmt1 : fmt2; 5269 5270 while ((c = *fmt++) != '\0') { 5271 switch (c) { 5272 default: 5273 rtld_putchar(c); 5274 continue; 5275 case '\\': 5276 switch (c = *fmt) { 5277 case '\0': 5278 continue; 5279 case 'n': 5280 rtld_putchar('\n'); 5281 break; 5282 case 't': 5283 rtld_putchar('\t'); 5284 break; 5285 } 5286 break; 5287 case '%': 5288 switch (c = *fmt) { 5289 case '\0': 5290 continue; 5291 case '%': 5292 default: 5293 rtld_putchar(c); 5294 break; 5295 case 'A': 5296 rtld_putstr(main_local); 5297 break; 5298 case 'a': 5299 rtld_putstr(obj_main->path); 5300 break; 5301 case 'o': 5302 rtld_putstr(name); 5303 break; 5304 case 'p': 5305 rtld_putstr(path); 5306 break; 5307 case 'x': 5308 rtld_printf("%p", 5309 obj != NULL ? obj->mapbase : NULL); 5310 break; 5311 } 5312 break; 5313 } 5314 ++fmt; 5315 } 5316 } 5317 5318 static void 5319 trace_loaded_objects(Obj_Entry *obj, bool show_preload) 5320 { 5321 const char *fmt1, *fmt2, *main_local; 5322 const char *name, *path; 5323 bool first_spurious, list_containers; 5324 5325 trace_calc_fmts(&main_local, &fmt1, &fmt2); 5326 list_containers = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_ALL) != NULL; 5327 5328 for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 5329 Needed_Entry *needed; 5330 5331 if (obj->marker) 5332 continue; 5333 if (list_containers && obj->needed != NULL) 5334 rtld_printf("%s:\n", obj->path); 5335 for (needed = obj->needed; needed; needed = needed->next) { 5336 if (needed->obj != NULL) { 5337 if (needed->obj->traced && !list_containers) 5338 continue; 5339 needed->obj->traced = true; 5340 path = needed->obj->path; 5341 } else 5342 path = "not found"; 5343 5344 name = obj->strtab + needed->name; 5345 trace_print_obj(needed->obj, name, path, main_local, 5346 fmt1, fmt2); 5347 } 5348 } 5349 5350 if (show_preload) { 5351 if (ld_get_env_var(LD_TRACE_LOADED_OBJECTS_FMT2) == NULL) 5352 fmt2 = "\t%p (%x)\n"; 5353 first_spurious = true; 5354 5355 TAILQ_FOREACH(obj, &obj_list, next) { 5356 if (obj->marker || obj == obj_main || obj->traced) 5357 continue; 5358 5359 if (list_containers && first_spurious) { 5360 rtld_printf("[preloaded]\n"); 5361 first_spurious = false; 5362 } 5363 5364 Name_Entry *fname = STAILQ_FIRST(&obj->names); 5365 name = fname == NULL ? "<unknown>" : fname->name; 5366 trace_print_obj(obj, name, obj->path, main_local, NULL, 5367 fmt2); 5368 } 5369 } 5370 } 5371 5372 /* 5373 * Unload a dlopened object and its dependencies from memory and from 5374 * our data structures. It is assumed that the DAG rooted in the 5375 * object has already been unreferenced, and that the object has a 5376 * reference count of 0. 5377 */ 5378 static void 5379 unload_object(Obj_Entry *root, RtldLockState *lockstate) 5380 { 5381 Obj_Entry marker, *obj, *next; 5382 5383 assert(root->refcount == 0); 5384 5385 /* 5386 * Pass over the DAG removing unreferenced objects from 5387 * appropriate lists. 5388 */ 5389 unlink_object(root); 5390 5391 /* Unmap all objects that are no longer referenced. */ 5392 for (obj = TAILQ_FIRST(&obj_list); obj != NULL; obj = next) { 5393 next = TAILQ_NEXT(obj, next); 5394 if (obj->marker || obj->refcount != 0) 5395 continue; 5396 LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 5397 0, obj->path); 5398 dbg("unloading \"%s\"", obj->path); 5399 /* 5400 * Unlink the object now to prevent new references from 5401 * being acquired while the bind lock is dropped in 5402 * recursive dlclose() invocations. 5403 */ 5404 TAILQ_REMOVE(&obj_list, obj, next); 5405 obj_count--; 5406 5407 if (obj->filtees_loaded) { 5408 if (next != NULL) { 5409 init_marker(&marker); 5410 TAILQ_INSERT_BEFORE(next, &marker, next); 5411 unload_filtees(obj, lockstate); 5412 next = TAILQ_NEXT(&marker, next); 5413 TAILQ_REMOVE(&obj_list, &marker, next); 5414 } else 5415 unload_filtees(obj, lockstate); 5416 } 5417 release_object(obj); 5418 } 5419 } 5420 5421 static void 5422 unlink_object(Obj_Entry *root) 5423 { 5424 Objlist_Entry *elm; 5425 5426 if (root->refcount == 0) { 5427 /* Remove the object from the RTLD_GLOBAL list. */ 5428 objlist_remove(&list_global, root); 5429 5430 /* Remove the object from all objects' DAG lists. */ 5431 STAILQ_FOREACH(elm, &root->dagmembers, link) { 5432 objlist_remove(&elm->obj->dldags, root); 5433 if (elm->obj != root) 5434 unlink_object(elm->obj); 5435 } 5436 } 5437 } 5438 5439 static void 5440 ref_dag(Obj_Entry *root) 5441 { 5442 Objlist_Entry *elm; 5443 5444 assert(root->dag_inited); 5445 STAILQ_FOREACH(elm, &root->dagmembers, link) 5446 elm->obj->refcount++; 5447 } 5448 5449 static void 5450 unref_dag(Obj_Entry *root) 5451 { 5452 Objlist_Entry *elm; 5453 5454 assert(root->dag_inited); 5455 STAILQ_FOREACH(elm, &root->dagmembers, link) 5456 elm->obj->refcount--; 5457 } 5458 5459 /* 5460 * Common code for MD __tls_get_addr(). 5461 */ 5462 static void * 5463 tls_get_addr_slow(struct tcb *tcb, int index, size_t offset, bool locked) 5464 { 5465 struct dtv *newdtv, *dtv; 5466 RtldLockState lockstate; 5467 int to_copy; 5468 5469 dtv = tcb->tcb_dtv; 5470 /* Check dtv generation in case new modules have arrived */ 5471 if (dtv->dtv_gen != tls_dtv_generation) { 5472 if (!locked) 5473 wlock_acquire(rtld_bind_lock, &lockstate); 5474 newdtv = xcalloc(1, sizeof(struct dtv) + tls_max_index * 5475 sizeof(struct dtv_slot)); 5476 to_copy = dtv->dtv_size; 5477 if (to_copy > tls_max_index) 5478 to_copy = tls_max_index; 5479 memcpy(newdtv->dtv_slots, dtv->dtv_slots, to_copy * 5480 sizeof(struct dtv_slot)); 5481 newdtv->dtv_gen = tls_dtv_generation; 5482 newdtv->dtv_size = tls_max_index; 5483 free(dtv); 5484 if (!locked) 5485 lock_release(rtld_bind_lock, &lockstate); 5486 dtv = tcb->tcb_dtv = newdtv; 5487 } 5488 5489 /* Dynamically allocate module TLS if necessary */ 5490 if (dtv->dtv_slots[index - 1].dtvs_tls == 0) { 5491 /* Signal safe, wlock will block out signals. */ 5492 if (!locked) 5493 wlock_acquire(rtld_bind_lock, &lockstate); 5494 if (!dtv->dtv_slots[index - 1].dtvs_tls) 5495 dtv->dtv_slots[index - 1].dtvs_tls = 5496 allocate_module_tls(tcb, index); 5497 if (!locked) 5498 lock_release(rtld_bind_lock, &lockstate); 5499 } 5500 return (dtv->dtv_slots[index - 1].dtvs_tls + offset); 5501 } 5502 5503 void * 5504 tls_get_addr_common(struct tcb *tcb, int index, size_t offset) 5505 { 5506 struct dtv *dtv; 5507 5508 dtv = tcb->tcb_dtv; 5509 /* Check dtv generation in case new modules have arrived */ 5510 if (__predict_true(dtv->dtv_gen == tls_dtv_generation && 5511 dtv->dtv_slots[index - 1].dtvs_tls != 0)) 5512 return (dtv->dtv_slots[index - 1].dtvs_tls + offset); 5513 return (tls_get_addr_slow(tcb, index, offset, false)); 5514 } 5515 5516 static struct tcb * 5517 tcb_from_tcb_list_entry(struct tcb_list_entry *tcbelm) 5518 { 5519 #ifdef TLS_VARIANT_I 5520 return ((struct tcb *)((char *)tcbelm - tcb_list_entry_offset)); 5521 #else 5522 return ((struct tcb *)((char *)tcbelm + tcb_list_entry_offset)); 5523 #endif 5524 } 5525 5526 static struct tcb_list_entry * 5527 tcb_list_entry_from_tcb(struct tcb *tcb) 5528 { 5529 #ifdef TLS_VARIANT_I 5530 return ((struct tcb_list_entry *)((char *)tcb + tcb_list_entry_offset)); 5531 #else 5532 return ((struct tcb_list_entry *)((char *)tcb - tcb_list_entry_offset)); 5533 #endif 5534 } 5535 5536 static void 5537 tcb_list_insert(struct tcb *tcb) 5538 { 5539 struct tcb_list_entry *tcbelm; 5540 5541 tcbelm = tcb_list_entry_from_tcb(tcb); 5542 TAILQ_INSERT_TAIL(&tcb_list, tcbelm, next); 5543 } 5544 5545 static void 5546 tcb_list_remove(struct tcb *tcb) 5547 { 5548 struct tcb_list_entry *tcbelm; 5549 5550 tcbelm = tcb_list_entry_from_tcb(tcb); 5551 TAILQ_REMOVE(&tcb_list, tcbelm, next); 5552 } 5553 5554 #ifdef TLS_VARIANT_I 5555 5556 /* 5557 * Return pointer to allocated TLS block 5558 */ 5559 static void * 5560 get_tls_block_ptr(void *tcb, size_t tcbsize) 5561 { 5562 size_t extra_size, post_size, pre_size, tls_block_size; 5563 size_t tls_init_align; 5564 5565 tls_init_align = MAX(obj_main->tlsalign, 1); 5566 5567 /* Compute fragments sizes. */ 5568 extra_size = tcbsize - TLS_TCB_SIZE; 5569 post_size = calculate_tls_post_size(tls_init_align); 5570 tls_block_size = tcbsize + post_size; 5571 pre_size = roundup2(tls_block_size, tls_init_align) - tls_block_size; 5572 5573 return ((char *)tcb - pre_size - extra_size); 5574 } 5575 5576 /* 5577 * Allocate Static TLS using the Variant I method. 5578 * 5579 * For details on the layout, see lib/libc/gen/tls.c. 5580 * 5581 * NB: rtld's tls_static_space variable includes TLS_TCB_SIZE and post_size as 5582 * it is based on tls_last_offset, and TLS offsets here are really TCB 5583 * offsets, whereas libc's tls_static_space is just the executable's static 5584 * TLS segment. 5585 * 5586 * NB: This differs from NetBSD's ld.elf_so, where TLS offsets are relative to 5587 * the end of the TCB. 5588 */ 5589 void * 5590 allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign) 5591 { 5592 Obj_Entry *obj; 5593 char *tls_block; 5594 struct dtv *dtv; 5595 struct tcb *tcb; 5596 char *addr; 5597 size_t i; 5598 size_t extra_size, maxalign, post_size, pre_size, tls_block_size; 5599 size_t tls_init_align, tls_init_offset, tls_bss_offset; 5600 5601 if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE) 5602 return (oldtcb); 5603 5604 assert(tcbsize >= TLS_TCB_SIZE); 5605 maxalign = MAX(tcbalign, tls_static_max_align); 5606 tls_init_align = MAX(obj_main->tlsalign, 1); 5607 5608 /* Compute fragments sizes. */ 5609 extra_size = tcbsize - TLS_TCB_SIZE; 5610 post_size = calculate_tls_post_size(tls_init_align); 5611 tls_block_size = tcbsize + post_size; 5612 pre_size = roundup2(tls_block_size, tls_init_align) - tls_block_size; 5613 tls_block_size += pre_size + tls_static_space - TLS_TCB_SIZE - 5614 post_size; 5615 5616 /* Allocate whole TLS block */ 5617 tls_block = xmalloc_aligned(tls_block_size, maxalign, 0); 5618 tcb = (struct tcb *)(tls_block + pre_size + extra_size); 5619 5620 if (oldtcb != NULL) { 5621 memcpy(tls_block, get_tls_block_ptr(oldtcb, tcbsize), 5622 tls_static_space); 5623 free(get_tls_block_ptr(oldtcb, tcbsize)); 5624 5625 /* Adjust the DTV. */ 5626 dtv = tcb->tcb_dtv; 5627 for (i = 0; i < dtv->dtv_size; i++) { 5628 if ((uintptr_t)dtv->dtv_slots[i].dtvs_tls >= 5629 (uintptr_t)oldtcb && 5630 (uintptr_t)dtv->dtv_slots[i].dtvs_tls < 5631 (uintptr_t)oldtcb + tls_static_space) { 5632 dtv->dtv_slots[i].dtvs_tls = (char *)tcb + 5633 (dtv->dtv_slots[i].dtvs_tls - 5634 (char *)oldtcb); 5635 } 5636 } 5637 } else { 5638 dtv = xcalloc(1, sizeof(struct dtv) + tls_max_index * 5639 sizeof(struct dtv_slot)); 5640 tcb->tcb_dtv = dtv; 5641 dtv->dtv_gen = tls_dtv_generation; 5642 dtv->dtv_size = tls_max_index; 5643 5644 for (obj = globallist_curr(objs); obj != NULL; 5645 obj = globallist_next(obj)) { 5646 if (obj->tlsoffset == 0) 5647 continue; 5648 tls_init_offset = obj->tlspoffset & (obj->tlsalign - 1); 5649 addr = (char *)tcb + obj->tlsoffset; 5650 if (tls_init_offset > 0) 5651 memset(addr, 0, tls_init_offset); 5652 if (obj->tlsinitsize > 0) { 5653 memcpy(addr + tls_init_offset, obj->tlsinit, 5654 obj->tlsinitsize); 5655 } 5656 if (obj->tlssize > obj->tlsinitsize) { 5657 tls_bss_offset = tls_init_offset + 5658 obj->tlsinitsize; 5659 memset(addr + tls_bss_offset, 0, 5660 obj->tlssize - tls_bss_offset); 5661 } 5662 dtv->dtv_slots[obj->tlsindex - 1].dtvs_tls = addr; 5663 } 5664 } 5665 5666 tcb_list_insert(tcb); 5667 return (tcb); 5668 } 5669 5670 void 5671 free_tls(void *tcb, size_t tcbsize, size_t tcbalign __unused) 5672 { 5673 struct dtv *dtv; 5674 uintptr_t tlsstart, tlsend; 5675 size_t post_size; 5676 size_t i, tls_init_align __unused; 5677 5678 tcb_list_remove(tcb); 5679 5680 assert(tcbsize >= TLS_TCB_SIZE); 5681 tls_init_align = MAX(obj_main->tlsalign, 1); 5682 5683 /* Compute fragments sizes. */ 5684 post_size = calculate_tls_post_size(tls_init_align); 5685 5686 tlsstart = (uintptr_t)tcb + TLS_TCB_SIZE + post_size; 5687 tlsend = (uintptr_t)tcb + tls_static_space; 5688 5689 dtv = ((struct tcb *)tcb)->tcb_dtv; 5690 for (i = 0; i < dtv->dtv_size; i++) { 5691 if (dtv->dtv_slots[i].dtvs_tls != NULL && 5692 ((uintptr_t)dtv->dtv_slots[i].dtvs_tls < tlsstart || 5693 (uintptr_t)dtv->dtv_slots[i].dtvs_tls >= tlsend)) { 5694 free(dtv->dtv_slots[i].dtvs_tls); 5695 } 5696 } 5697 free(dtv); 5698 free(get_tls_block_ptr(tcb, tcbsize)); 5699 } 5700 5701 #endif /* TLS_VARIANT_I */ 5702 5703 #ifdef TLS_VARIANT_II 5704 5705 /* 5706 * Allocate Static TLS using the Variant II method. 5707 */ 5708 void * 5709 allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign) 5710 { 5711 Obj_Entry *obj; 5712 size_t size, ralign; 5713 char *tls_block; 5714 struct dtv *dtv, *olddtv; 5715 struct tcb *tcb; 5716 char *addr; 5717 size_t i; 5718 5719 ralign = tcbalign; 5720 if (tls_static_max_align > ralign) 5721 ralign = tls_static_max_align; 5722 size = roundup(tls_static_space, ralign) + roundup(tcbsize, ralign); 5723 5724 assert(tcbsize >= 2 * sizeof(uintptr_t)); 5725 tls_block = xmalloc_aligned(size, ralign, 0 /* XXX */); 5726 dtv = xcalloc(1, sizeof(struct dtv) + tls_max_index * 5727 sizeof(struct dtv_slot)); 5728 5729 tcb = (struct tcb *)(tls_block + roundup(tls_static_space, ralign)); 5730 tcb->tcb_self = tcb; 5731 tcb->tcb_dtv = dtv; 5732 5733 dtv->dtv_gen = tls_dtv_generation; 5734 dtv->dtv_size = tls_max_index; 5735 5736 if (oldtcb != NULL) { 5737 /* 5738 * Copy the static TLS block over whole. 5739 */ 5740 memcpy((char *)tcb - tls_static_space, 5741 (const char *)oldtcb - tls_static_space, 5742 tls_static_space); 5743 5744 /* 5745 * If any dynamic TLS blocks have been created tls_get_addr(), 5746 * move them over. 5747 */ 5748 olddtv = ((struct tcb *)oldtcb)->tcb_dtv; 5749 for (i = 0; i < olddtv->dtv_size; i++) { 5750 if ((uintptr_t)olddtv->dtv_slots[i].dtvs_tls < 5751 (uintptr_t)oldtcb - size || 5752 (uintptr_t)olddtv->dtv_slots[i].dtvs_tls > 5753 (uintptr_t)oldtcb) { 5754 dtv->dtv_slots[i].dtvs_tls = 5755 olddtv->dtv_slots[i].dtvs_tls; 5756 olddtv->dtv_slots[i].dtvs_tls = NULL; 5757 } 5758 } 5759 5760 /* 5761 * We assume that this block was the one we created with 5762 * allocate_initial_tls(). 5763 */ 5764 free_tls(oldtcb, 2 * sizeof(uintptr_t), sizeof(uintptr_t)); 5765 } else { 5766 for (obj = objs; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 5767 if (obj->marker || obj->tlsoffset == 0) 5768 continue; 5769 addr = (char *)tcb - obj->tlsoffset; 5770 memset(addr + obj->tlsinitsize, 0, obj->tlssize - 5771 obj->tlsinitsize); 5772 if (obj->tlsinit) { 5773 memcpy(addr, obj->tlsinit, obj->tlsinitsize); 5774 obj->static_tls_copied = true; 5775 } 5776 dtv->dtv_slots[obj->tlsindex - 1].dtvs_tls = addr; 5777 } 5778 } 5779 5780 tcb_list_insert(tcb); 5781 return (tcb); 5782 } 5783 5784 void 5785 free_tls(void *tcb, size_t tcbsize __unused, size_t tcbalign) 5786 { 5787 struct dtv *dtv; 5788 size_t size, ralign; 5789 size_t i; 5790 uintptr_t tlsstart, tlsend; 5791 5792 tcb_list_remove(tcb); 5793 5794 /* 5795 * Figure out the size of the initial TLS block so that we can 5796 * find stuff which ___tls_get_addr() allocated dynamically. 5797 */ 5798 ralign = tcbalign; 5799 if (tls_static_max_align > ralign) 5800 ralign = tls_static_max_align; 5801 size = roundup(tls_static_space, ralign); 5802 5803 dtv = ((struct tcb *)tcb)->tcb_dtv; 5804 tlsend = (uintptr_t)tcb; 5805 tlsstart = tlsend - size; 5806 for (i = 0; i < dtv->dtv_size; i++) { 5807 if (dtv->dtv_slots[i].dtvs_tls != NULL && 5808 ((uintptr_t)dtv->dtv_slots[i].dtvs_tls < tlsstart || 5809 (uintptr_t)dtv->dtv_slots[i].dtvs_tls > tlsend)) { 5810 free(dtv->dtv_slots[i].dtvs_tls); 5811 } 5812 } 5813 5814 free((void *)tlsstart); 5815 free(dtv); 5816 } 5817 5818 #endif /* TLS_VARIANT_II */ 5819 5820 /* 5821 * Allocate TLS block for module with given index. 5822 */ 5823 void * 5824 allocate_module_tls(struct tcb *tcb, int index) 5825 { 5826 Obj_Entry *obj; 5827 char *p; 5828 5829 TAILQ_FOREACH(obj, &obj_list, next) { 5830 if (obj->marker) 5831 continue; 5832 if (obj->tlsindex == index) 5833 break; 5834 } 5835 if (obj == NULL) { 5836 _rtld_error("Can't find module with TLS index %d", index); 5837 rtld_die(); 5838 } 5839 5840 if (obj->tls_static) { 5841 #ifdef TLS_VARIANT_I 5842 p = (char *)tcb + obj->tlsoffset; 5843 #else 5844 p = (char *)tcb - obj->tlsoffset; 5845 #endif 5846 return (p); 5847 } 5848 5849 obj->tls_dynamic = true; 5850 5851 p = xmalloc_aligned(obj->tlssize, obj->tlsalign, obj->tlspoffset); 5852 memcpy(p, obj->tlsinit, obj->tlsinitsize); 5853 memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize); 5854 return (p); 5855 } 5856 5857 static bool 5858 allocate_tls_offset_common(size_t *offp, size_t tlssize, size_t tlsalign, 5859 size_t tlspoffset __unused) 5860 { 5861 size_t off; 5862 5863 if (tls_last_offset == 0) 5864 off = calculate_first_tls_offset(tlssize, tlsalign, 5865 tlspoffset); 5866 else 5867 off = calculate_tls_offset(tls_last_offset, tls_last_size, 5868 tlssize, tlsalign, tlspoffset); 5869 5870 *offp = off; 5871 #ifdef TLS_VARIANT_I 5872 off += tlssize; 5873 #endif 5874 5875 /* 5876 * If we have already fixed the size of the static TLS block, we 5877 * must stay within that size. When allocating the static TLS, we 5878 * leave a small amount of space spare to be used for dynamically 5879 * loading modules which use static TLS. 5880 */ 5881 if (tls_static_space != 0) { 5882 if (off > tls_static_space) 5883 return (false); 5884 } else if (tlsalign > tls_static_max_align) { 5885 tls_static_max_align = tlsalign; 5886 } 5887 5888 tls_last_offset = off; 5889 tls_last_size = tlssize; 5890 5891 return (true); 5892 } 5893 5894 bool 5895 allocate_tls_offset(Obj_Entry *obj) 5896 { 5897 if (obj->tls_dynamic) 5898 return (false); 5899 5900 if (obj->tls_static) 5901 return (true); 5902 5903 if (obj->tlssize == 0) { 5904 obj->tls_static = true; 5905 return (true); 5906 } 5907 5908 if (!allocate_tls_offset_common(&obj->tlsoffset, obj->tlssize, 5909 obj->tlsalign, obj->tlspoffset)) 5910 return (false); 5911 5912 obj->tls_static = true; 5913 5914 return (true); 5915 } 5916 5917 void 5918 free_tls_offset(Obj_Entry *obj) 5919 { 5920 /* 5921 * If we were the last thing to allocate out of the static TLS 5922 * block, we give our space back to the 'allocator'. This is a 5923 * simplistic workaround to allow libGL.so.1 to be loaded and 5924 * unloaded multiple times. 5925 */ 5926 size_t off = obj->tlsoffset; 5927 5928 #ifdef TLS_VARIANT_I 5929 off += obj->tlssize; 5930 #endif 5931 if (off == tls_last_offset) { 5932 tls_last_offset -= obj->tlssize; 5933 tls_last_size = 0; 5934 } 5935 } 5936 5937 void * 5938 _rtld_allocate_tls(void *oldtcb, size_t tcbsize, size_t tcbalign) 5939 { 5940 void *ret; 5941 RtldLockState lockstate; 5942 5943 wlock_acquire(rtld_bind_lock, &lockstate); 5944 ret = allocate_tls(globallist_curr(TAILQ_FIRST(&obj_list)), oldtcb, 5945 tcbsize, tcbalign); 5946 lock_release(rtld_bind_lock, &lockstate); 5947 return (ret); 5948 } 5949 5950 void 5951 _rtld_free_tls(void *tcb, size_t tcbsize, size_t tcbalign) 5952 { 5953 RtldLockState lockstate; 5954 5955 wlock_acquire(rtld_bind_lock, &lockstate); 5956 free_tls(tcb, tcbsize, tcbalign); 5957 lock_release(rtld_bind_lock, &lockstate); 5958 } 5959 5960 static void 5961 object_add_name(Obj_Entry *obj, const char *name) 5962 { 5963 Name_Entry *entry; 5964 size_t len; 5965 5966 len = strlen(name); 5967 entry = malloc(sizeof(Name_Entry) + len); 5968 5969 if (entry != NULL) { 5970 strcpy(entry->name, name); 5971 STAILQ_INSERT_TAIL(&obj->names, entry, link); 5972 } 5973 } 5974 5975 static int 5976 object_match_name(const Obj_Entry *obj, const char *name) 5977 { 5978 Name_Entry *entry; 5979 5980 STAILQ_FOREACH(entry, &obj->names, link) { 5981 if (strcmp(name, entry->name) == 0) 5982 return (1); 5983 } 5984 return (0); 5985 } 5986 5987 static Obj_Entry * 5988 locate_dependency(const Obj_Entry *obj, const char *name) 5989 { 5990 const Objlist_Entry *entry; 5991 const Needed_Entry *needed; 5992 5993 STAILQ_FOREACH(entry, &list_main, link) { 5994 if (object_match_name(entry->obj, name)) 5995 return (entry->obj); 5996 } 5997 5998 for (needed = obj->needed; needed != NULL; needed = needed->next) { 5999 if (strcmp(obj->strtab + needed->name, name) == 0 || 6000 (needed->obj != NULL && object_match_name(needed->obj, 6001 name))) { 6002 /* 6003 * If there is DT_NEEDED for the name we are looking 6004 * for, we are all set. Note that object might not be 6005 * found if dependency was not loaded yet, so the 6006 * function can return NULL here. This is expected and 6007 * handled properly by the caller. 6008 */ 6009 return (needed->obj); 6010 } 6011 } 6012 _rtld_error("%s: Unexpected inconsistency: dependency %s not found", 6013 obj->path, name); 6014 rtld_die(); 6015 } 6016 6017 static int 6018 check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj, 6019 const Elf_Vernaux *vna) 6020 { 6021 const Elf_Verdef *vd; 6022 const char *vername; 6023 6024 vername = refobj->strtab + vna->vna_name; 6025 vd = depobj->verdef; 6026 if (vd == NULL) { 6027 _rtld_error("%s: version %s required by %s not defined", 6028 depobj->path, vername, refobj->path); 6029 return (-1); 6030 } 6031 for (;;) { 6032 if (vd->vd_version != VER_DEF_CURRENT) { 6033 _rtld_error( 6034 "%s: Unsupported version %d of Elf_Verdef entry", 6035 depobj->path, vd->vd_version); 6036 return (-1); 6037 } 6038 if (vna->vna_hash == vd->vd_hash) { 6039 const Elf_Verdaux *aux = 6040 (const Elf_Verdaux *)((const char *)vd + 6041 vd->vd_aux); 6042 if (strcmp(vername, depobj->strtab + aux->vda_name) == 6043 0) 6044 return (0); 6045 } 6046 if (vd->vd_next == 0) 6047 break; 6048 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 6049 } 6050 if (vna->vna_flags & VER_FLG_WEAK) 6051 return (0); 6052 _rtld_error("%s: version %s required by %s not found", depobj->path, 6053 vername, refobj->path); 6054 return (-1); 6055 } 6056 6057 static int 6058 rtld_verify_object_versions(Obj_Entry *obj) 6059 { 6060 const Elf_Verneed *vn; 6061 const Elf_Verdef *vd; 6062 const Elf_Verdaux *vda; 6063 const Elf_Vernaux *vna; 6064 const Obj_Entry *depobj; 6065 int maxvernum, vernum; 6066 6067 if (obj->ver_checked) 6068 return (0); 6069 obj->ver_checked = true; 6070 6071 maxvernum = 0; 6072 /* 6073 * Walk over defined and required version records and figure out 6074 * max index used by any of them. Do very basic sanity checking 6075 * while there. 6076 */ 6077 vn = obj->verneed; 6078 while (vn != NULL) { 6079 if (vn->vn_version != VER_NEED_CURRENT) { 6080 _rtld_error( 6081 "%s: Unsupported version %d of Elf_Verneed entry", 6082 obj->path, vn->vn_version); 6083 return (-1); 6084 } 6085 vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux); 6086 for (;;) { 6087 vernum = VER_NEED_IDX(vna->vna_other); 6088 if (vernum > maxvernum) 6089 maxvernum = vernum; 6090 if (vna->vna_next == 0) 6091 break; 6092 vna = (const Elf_Vernaux *)((const char *)vna + 6093 vna->vna_next); 6094 } 6095 if (vn->vn_next == 0) 6096 break; 6097 vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next); 6098 } 6099 6100 vd = obj->verdef; 6101 while (vd != NULL) { 6102 if (vd->vd_version != VER_DEF_CURRENT) { 6103 _rtld_error( 6104 "%s: Unsupported version %d of Elf_Verdef entry", 6105 obj->path, vd->vd_version); 6106 return (-1); 6107 } 6108 vernum = VER_DEF_IDX(vd->vd_ndx); 6109 if (vernum > maxvernum) 6110 maxvernum = vernum; 6111 if (vd->vd_next == 0) 6112 break; 6113 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 6114 } 6115 6116 if (maxvernum == 0) 6117 return (0); 6118 6119 /* 6120 * Store version information in array indexable by version index. 6121 * Verify that object version requirements are satisfied along the 6122 * way. 6123 */ 6124 obj->vernum = maxvernum + 1; 6125 obj->vertab = xcalloc(obj->vernum, sizeof(Ver_Entry)); 6126 6127 vd = obj->verdef; 6128 while (vd != NULL) { 6129 if ((vd->vd_flags & VER_FLG_BASE) == 0) { 6130 vernum = VER_DEF_IDX(vd->vd_ndx); 6131 assert(vernum <= maxvernum); 6132 vda = (const Elf_Verdaux *)((const char *)vd + 6133 vd->vd_aux); 6134 obj->vertab[vernum].hash = vd->vd_hash; 6135 obj->vertab[vernum].name = obj->strtab + vda->vda_name; 6136 obj->vertab[vernum].file = NULL; 6137 obj->vertab[vernum].flags = 0; 6138 } 6139 if (vd->vd_next == 0) 6140 break; 6141 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 6142 } 6143 6144 vn = obj->verneed; 6145 while (vn != NULL) { 6146 depobj = locate_dependency(obj, obj->strtab + vn->vn_file); 6147 if (depobj == NULL) 6148 return (-1); 6149 vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux); 6150 for (;;) { 6151 if (check_object_provided_version(obj, depobj, vna)) 6152 return (-1); 6153 vernum = VER_NEED_IDX(vna->vna_other); 6154 assert(vernum <= maxvernum); 6155 obj->vertab[vernum].hash = vna->vna_hash; 6156 obj->vertab[vernum].name = obj->strtab + vna->vna_name; 6157 obj->vertab[vernum].file = obj->strtab + vn->vn_file; 6158 obj->vertab[vernum].flags = (vna->vna_other & 6159 VER_NEED_HIDDEN) != 0 ? VER_INFO_HIDDEN : 0; 6160 if (vna->vna_next == 0) 6161 break; 6162 vna = (const Elf_Vernaux *)((const char *)vna + 6163 vna->vna_next); 6164 } 6165 if (vn->vn_next == 0) 6166 break; 6167 vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next); 6168 } 6169 return (0); 6170 } 6171 6172 static int 6173 rtld_verify_versions(const Objlist *objlist) 6174 { 6175 Objlist_Entry *entry; 6176 int rc; 6177 6178 rc = 0; 6179 STAILQ_FOREACH(entry, objlist, link) { 6180 /* 6181 * Skip dummy objects or objects that have their version 6182 * requirements already checked. 6183 */ 6184 if (entry->obj->strtab == NULL || entry->obj->vertab != NULL) 6185 continue; 6186 if (rtld_verify_object_versions(entry->obj) == -1) { 6187 rc = -1; 6188 if (ld_tracing == NULL) 6189 break; 6190 } 6191 } 6192 if (rc == 0 || ld_tracing != NULL) 6193 rc = rtld_verify_object_versions(&obj_rtld); 6194 return (rc); 6195 } 6196 6197 const Ver_Entry * 6198 fetch_ventry(const Obj_Entry *obj, unsigned long symnum) 6199 { 6200 Elf_Versym vernum; 6201 6202 if (obj->vertab) { 6203 vernum = VER_NDX(obj->versyms[symnum]); 6204 if (vernum >= obj->vernum) { 6205 _rtld_error("%s: symbol %s has wrong verneed value %d", 6206 obj->path, obj->strtab + symnum, vernum); 6207 } else if (obj->vertab[vernum].hash != 0) { 6208 return (&obj->vertab[vernum]); 6209 } 6210 } 6211 return (NULL); 6212 } 6213 6214 int 6215 _rtld_get_stack_prot(void) 6216 { 6217 return (stack_prot); 6218 } 6219 6220 int 6221 _rtld_is_dlopened(void *arg) 6222 { 6223 Obj_Entry *obj; 6224 RtldLockState lockstate; 6225 int res; 6226 6227 rlock_acquire(rtld_bind_lock, &lockstate); 6228 obj = dlcheck(arg); 6229 if (obj == NULL) 6230 obj = obj_from_addr(arg); 6231 if (obj == NULL) { 6232 _rtld_error("No shared object contains address"); 6233 lock_release(rtld_bind_lock, &lockstate); 6234 return (-1); 6235 } 6236 res = obj->dlopened ? 1 : 0; 6237 lock_release(rtld_bind_lock, &lockstate); 6238 return (res); 6239 } 6240 6241 static int 6242 obj_remap_relro(Obj_Entry *obj, int prot) 6243 { 6244 const Elf_Phdr *ph; 6245 caddr_t relro_page; 6246 size_t relro_size; 6247 6248 for (ph = obj->phdr; ph < obj->phdr + obj->phnum; ph++) { 6249 if (ph->p_type != PT_GNU_RELRO) 6250 continue; 6251 relro_page = obj->relocbase + rtld_trunc_page(ph->p_vaddr); 6252 relro_size = rtld_round_page(ph->p_vaddr + ph->p_memsz) - 6253 rtld_trunc_page(ph->p_vaddr); 6254 if (mprotect(relro_page, relro_size, prot) == -1) { 6255 _rtld_error( 6256 "%s: Cannot set relro protection to %#x: %s", 6257 obj->path, prot, rtld_strerror(errno)); 6258 return (-1); 6259 } 6260 break; 6261 } 6262 return (0); 6263 } 6264 6265 static int 6266 obj_disable_relro(Obj_Entry *obj) 6267 { 6268 return (obj_remap_relro(obj, PROT_READ | PROT_WRITE)); 6269 } 6270 6271 static int 6272 obj_enforce_relro(Obj_Entry *obj) 6273 { 6274 return (obj_remap_relro(obj, PROT_READ)); 6275 } 6276 6277 static void 6278 map_stacks_exec(RtldLockState *lockstate) 6279 { 6280 void (*thr_map_stacks_exec)(void); 6281 6282 if ((max_stack_flags & PF_X) == 0 || (stack_prot & PROT_EXEC) != 0) 6283 return; 6284 thr_map_stacks_exec = (void (*)(void))( 6285 uintptr_t)get_program_var_addr("__pthread_map_stacks_exec", 6286 lockstate); 6287 if (thr_map_stacks_exec != NULL) { 6288 stack_prot |= PROT_EXEC; 6289 thr_map_stacks_exec(); 6290 } 6291 } 6292 6293 static void 6294 distribute_static_tls(Objlist *list) 6295 { 6296 struct tcb_list_entry *tcbelm; 6297 Objlist_Entry *objelm; 6298 struct tcb *tcb; 6299 Obj_Entry *obj; 6300 char *tlsbase; 6301 6302 STAILQ_FOREACH(objelm, list, link) { 6303 obj = objelm->obj; 6304 if (obj->marker || !obj->tls_static || obj->static_tls_copied) 6305 continue; 6306 TAILQ_FOREACH(tcbelm, &tcb_list, next) { 6307 tcb = tcb_from_tcb_list_entry(tcbelm); 6308 #ifdef TLS_VARIANT_I 6309 tlsbase = (char *)tcb + obj->tlsoffset; 6310 #else 6311 tlsbase = (char *)tcb - obj->tlsoffset; 6312 #endif 6313 memcpy(tlsbase, obj->tlsinit, obj->tlsinitsize); 6314 memset(tlsbase + obj->tlsinitsize, 0, 6315 obj->tlssize - obj->tlsinitsize); 6316 } 6317 obj->static_tls_copied = true; 6318 } 6319 } 6320 6321 void 6322 symlook_init(SymLook *dst, const char *name) 6323 { 6324 bzero(dst, sizeof(*dst)); 6325 dst->name = name; 6326 dst->hash = elf_hash(name); 6327 dst->hash_gnu = gnu_hash(name); 6328 } 6329 6330 static void 6331 symlook_init_from_req(SymLook *dst, const SymLook *src) 6332 { 6333 dst->name = src->name; 6334 dst->hash = src->hash; 6335 dst->hash_gnu = src->hash_gnu; 6336 dst->ventry = src->ventry; 6337 dst->flags = src->flags; 6338 dst->defobj_out = NULL; 6339 dst->sym_out = NULL; 6340 dst->lockstate = src->lockstate; 6341 dst->donelist_mem = NULL; 6342 } 6343 6344 static int 6345 open_binary_fd(const char *argv0, bool search_in_path, const char **binpath_res) 6346 { 6347 char *binpath, *pathenv, *pe, *res1; 6348 const char *res; 6349 int fd; 6350 6351 binpath = NULL; 6352 res = NULL; 6353 if (search_in_path && strchr(argv0, '/') == NULL) { 6354 binpath = xmalloc(PATH_MAX); 6355 pathenv = getenv("PATH"); 6356 if (pathenv == NULL) { 6357 _rtld_error("-p and no PATH environment variable"); 6358 rtld_die(); 6359 } 6360 pathenv = strdup(pathenv); 6361 if (pathenv == NULL) { 6362 _rtld_error("Cannot allocate memory"); 6363 rtld_die(); 6364 } 6365 fd = -1; 6366 errno = ENOENT; 6367 while ((pe = strsep(&pathenv, ":")) != NULL) { 6368 if (strlcpy(binpath, pe, PATH_MAX) >= PATH_MAX) 6369 continue; 6370 if (binpath[0] != '\0' && 6371 strlcat(binpath, "/", PATH_MAX) >= PATH_MAX) 6372 continue; 6373 if (strlcat(binpath, argv0, PATH_MAX) >= PATH_MAX) 6374 continue; 6375 fd = open(binpath, O_RDONLY | O_CLOEXEC | O_VERIFY); 6376 if (fd != -1 || errno != ENOENT) { 6377 res = binpath; 6378 break; 6379 } 6380 } 6381 free(pathenv); 6382 } else { 6383 fd = open(argv0, O_RDONLY | O_CLOEXEC | O_VERIFY); 6384 res = argv0; 6385 } 6386 6387 if (fd == -1) { 6388 _rtld_error("Cannot open %s: %s", argv0, rtld_strerror(errno)); 6389 rtld_die(); 6390 } 6391 if (res != NULL && res[0] != '/') { 6392 res1 = xmalloc(PATH_MAX); 6393 if (realpath(res, res1) != NULL) { 6394 if (res != argv0) 6395 free(__DECONST(char *, res)); 6396 res = res1; 6397 } else { 6398 free(res1); 6399 } 6400 } 6401 *binpath_res = res; 6402 return (fd); 6403 } 6404 6405 /* 6406 * Parse a set of command-line arguments. 6407 */ 6408 static int 6409 parse_args(char *argv[], int argc, bool *use_pathp, int *fdp, 6410 const char **argv0, bool *dir_ignore) 6411 { 6412 const char *arg; 6413 char machine[64]; 6414 size_t sz; 6415 int arglen, fd, i, j, mib[2]; 6416 char opt; 6417 bool seen_b, seen_f; 6418 6419 dbg("Parsing command-line arguments"); 6420 *use_pathp = false; 6421 *fdp = -1; 6422 *dir_ignore = false; 6423 seen_b = seen_f = false; 6424 6425 for (i = 1; i < argc; i++) { 6426 arg = argv[i]; 6427 dbg("argv[%d]: '%s'", i, arg); 6428 6429 /* 6430 * rtld arguments end with an explicit "--" or with the first 6431 * non-prefixed argument. 6432 */ 6433 if (strcmp(arg, "--") == 0) { 6434 i++; 6435 break; 6436 } 6437 if (arg[0] != '-') 6438 break; 6439 6440 /* 6441 * All other arguments are single-character options that can 6442 * be combined, so we need to search through `arg` for them. 6443 */ 6444 arglen = strlen(arg); 6445 for (j = 1; j < arglen; j++) { 6446 opt = arg[j]; 6447 if (opt == 'h') { 6448 print_usage(argv[0]); 6449 _exit(0); 6450 } else if (opt == 'b') { 6451 if (seen_f) { 6452 _rtld_error("Both -b and -f specified"); 6453 rtld_die(); 6454 } 6455 if (j != arglen - 1) { 6456 _rtld_error("Invalid options: %s", arg); 6457 rtld_die(); 6458 } 6459 i++; 6460 *argv0 = argv[i]; 6461 seen_b = true; 6462 break; 6463 } else if (opt == 'd') { 6464 *dir_ignore = true; 6465 } else if (opt == 'f') { 6466 if (seen_b) { 6467 _rtld_error("Both -b and -f specified"); 6468 rtld_die(); 6469 } 6470 6471 /* 6472 * -f XX can be used to specify a 6473 * descriptor for the binary named at 6474 * the command line (i.e., the later 6475 * argument will specify the process 6476 * name but the descriptor is what 6477 * will actually be executed). 6478 * 6479 * -f must be the last option in the 6480 * group, e.g., -abcf <fd>. 6481 */ 6482 if (j != arglen - 1) { 6483 _rtld_error("Invalid options: %s", arg); 6484 rtld_die(); 6485 } 6486 i++; 6487 fd = parse_integer(argv[i]); 6488 if (fd == -1) { 6489 _rtld_error( 6490 "Invalid file descriptor: '%s'", 6491 argv[i]); 6492 rtld_die(); 6493 } 6494 *fdp = fd; 6495 seen_f = true; 6496 break; 6497 } else if (opt == 'o') { 6498 struct ld_env_var_desc *l; 6499 char *n, *v; 6500 u_int ll; 6501 6502 if (j != arglen - 1) { 6503 _rtld_error("Invalid options: %s", arg); 6504 rtld_die(); 6505 } 6506 i++; 6507 n = argv[i]; 6508 v = strchr(n, '='); 6509 if (v == NULL) { 6510 _rtld_error("No '=' in -o parameter"); 6511 rtld_die(); 6512 } 6513 for (ll = 0; ll < nitems(ld_env_vars); ll++) { 6514 l = &ld_env_vars[ll]; 6515 if (v - n == (ptrdiff_t)strlen(l->n) && 6516 strncmp(n, l->n, v - n) == 0) { 6517 l->val = v + 1; 6518 break; 6519 } 6520 } 6521 if (ll == nitems(ld_env_vars)) { 6522 _rtld_error("Unknown LD_ option %s", n); 6523 rtld_die(); 6524 } 6525 } else if (opt == 'p') { 6526 *use_pathp = true; 6527 } else if (opt == 'u') { 6528 u_int ll; 6529 6530 for (ll = 0; ll < nitems(ld_env_vars); ll++) 6531 ld_env_vars[ll].val = NULL; 6532 } else if (opt == 'v') { 6533 machine[0] = '\0'; 6534 mib[0] = CTL_HW; 6535 mib[1] = HW_MACHINE; 6536 sz = sizeof(machine); 6537 sysctl(mib, nitems(mib), machine, &sz, NULL, 0); 6538 ld_elf_hints_path = ld_get_env_var( 6539 LD_ELF_HINTS_PATH); 6540 set_ld_elf_hints_path(); 6541 rtld_printf( 6542 "FreeBSD ld-elf.so.1 %s\n" 6543 "FreeBSD_version %d\n" 6544 "Default lib path %s\n" 6545 "Hints lib path %s\n" 6546 "Env prefix %s\n" 6547 "Default hint file %s\n" 6548 "Hint file %s\n" 6549 "libmap file %s\n" 6550 "Optional static TLS size %zd bytes\n", 6551 machine, __FreeBSD_version, 6552 ld_standard_library_path, gethints(false), 6553 ld_env_prefix, ld_elf_hints_default, 6554 ld_elf_hints_path, ld_path_libmap_conf, 6555 ld_static_tls_extra); 6556 _exit(0); 6557 } else { 6558 _rtld_error("Invalid argument: '%s'", arg); 6559 print_usage(argv[0]); 6560 rtld_die(); 6561 } 6562 } 6563 } 6564 6565 if (!seen_b) 6566 *argv0 = argv[i]; 6567 return (i); 6568 } 6569 6570 /* 6571 * Parse a file descriptor number without pulling in more of libc (e.g. atoi). 6572 */ 6573 static int 6574 parse_integer(const char *str) 6575 { 6576 int radix; 6577 const char *orig; 6578 int n, val; 6579 char c; 6580 6581 if (str[0] == '0') { 6582 if (str[1] == 'x') { 6583 str += 2; 6584 radix = 16; 6585 } else if (str[1] == 'b') { 6586 str += 2; 6587 radix = 2; 6588 } else { 6589 str += 1; 6590 radix = 8; 6591 } 6592 } else { 6593 radix = 10; 6594 } 6595 orig = str; 6596 n = 0; 6597 for (c = *str; c != '\0'; c = *++str) { 6598 if (c >= '0' && c <= '9') 6599 val = c - '0'; 6600 else if (c >= 'a' && c <= 'f') 6601 val = c - 'a' + 10; 6602 else if (c >= 'A' && c <= 'F') 6603 val = c - 'A' + 10; 6604 else 6605 return (-1); 6606 if (val >= radix) 6607 return (-1); 6608 6609 if (n > INT_MAX / radix) 6610 return (-1); 6611 n *= radix; 6612 if (n > INT_MAX - val) 6613 return (-1); 6614 n += val; 6615 } 6616 6617 /* 6618 * Make sure we actually parsed something. 6619 * Allow for lone '0'. 6620 */ 6621 if (str == orig && radix != 8) 6622 return (-1); 6623 return (n); 6624 } 6625 6626 static void 6627 print_usage(const char *argv0) 6628 { 6629 rtld_printf( 6630 "Usage: %s [-h] [-b <exe>] [-d] [-f <FD>] [-p] [--] <binary> [<args>]\n" 6631 "\n" 6632 "Options:\n" 6633 " -h Display this help message\n" 6634 " -b <exe> Execute <exe> instead of <binary>, arg0 is <binary>\n" 6635 " -d Ignore lack of exec permissions for the binary\n" 6636 " -f <FD> Execute <FD> instead of searching for <binary>\n" 6637 " -o <OPT>=<VAL> Set LD_<OPT> to <VAL>, without polluting env\n" 6638 " -p Search in PATH for named binary\n" 6639 " -u Ignore LD_ environment variables\n" 6640 " -v Display identification information\n" 6641 " -- End of RTLD options\n" 6642 " <binary> Name of process to execute\n" 6643 " <args> Arguments to the executed process\n", 6644 argv0); 6645 } 6646 6647 #define AUXFMT(at, xfmt) [at] = { .name = #at, .fmt = xfmt } 6648 static const struct auxfmt { 6649 const char *name; 6650 const char *fmt; 6651 } auxfmts[] = { 6652 AUXFMT(AT_NULL, NULL), 6653 AUXFMT(AT_IGNORE, NULL), 6654 AUXFMT(AT_EXECFD, "%ld"), 6655 AUXFMT(AT_PHDR, "%p"), 6656 AUXFMT(AT_PHENT, "%lu"), 6657 AUXFMT(AT_PHNUM, "%lu"), 6658 AUXFMT(AT_PAGESZ, "%lu"), 6659 AUXFMT(AT_BASE, "%#lx"), 6660 AUXFMT(AT_FLAGS, "%#lx"), 6661 AUXFMT(AT_ENTRY, "%p"), 6662 AUXFMT(AT_NOTELF, NULL), 6663 AUXFMT(AT_UID, "%ld"), 6664 AUXFMT(AT_EUID, "%ld"), 6665 AUXFMT(AT_GID, "%ld"), 6666 AUXFMT(AT_EGID, "%ld"), 6667 AUXFMT(AT_EXECPATH, "%s"), 6668 AUXFMT(AT_CANARY, "%p"), 6669 AUXFMT(AT_CANARYLEN, "%lu"), 6670 AUXFMT(AT_OSRELDATE, "%lu"), 6671 AUXFMT(AT_NCPUS, "%lu"), 6672 AUXFMT(AT_PAGESIZES, "%p"), 6673 AUXFMT(AT_PAGESIZESLEN, "%lu"), 6674 AUXFMT(AT_TIMEKEEP, "%p"), 6675 AUXFMT(AT_STACKPROT, "%#lx"), 6676 AUXFMT(AT_EHDRFLAGS, "%#lx"), 6677 AUXFMT(AT_HWCAP, "%#lx"), 6678 AUXFMT(AT_HWCAP2, "%#lx"), 6679 AUXFMT(AT_BSDFLAGS, "%#lx"), 6680 AUXFMT(AT_ARGC, "%lu"), 6681 AUXFMT(AT_ARGV, "%p"), 6682 AUXFMT(AT_ENVC, "%p"), 6683 AUXFMT(AT_ENVV, "%p"), 6684 AUXFMT(AT_PS_STRINGS, "%p"), 6685 AUXFMT(AT_FXRNG, "%p"), 6686 AUXFMT(AT_KPRELOAD, "%p"), 6687 AUXFMT(AT_USRSTACKBASE, "%#lx"), 6688 AUXFMT(AT_USRSTACKLIM, "%#lx"), 6689 /* AT_CHERI_STATS */ 6690 AUXFMT(AT_HWCAP3, "%#lx"), 6691 AUXFMT(AT_HWCAP4, "%#lx"), 6692 6693 }; 6694 6695 static bool 6696 is_ptr_fmt(const char *fmt) 6697 { 6698 char last; 6699 6700 last = fmt[strlen(fmt) - 1]; 6701 return (last == 'p' || last == 's'); 6702 } 6703 6704 static void 6705 dump_auxv(Elf_Auxinfo **aux_info) 6706 { 6707 Elf_Auxinfo *auxp; 6708 const struct auxfmt *fmt; 6709 int i; 6710 6711 for (i = 0; i < AT_COUNT; i++) { 6712 auxp = aux_info[i]; 6713 if (auxp == NULL) 6714 continue; 6715 fmt = &auxfmts[i]; 6716 if (fmt->fmt == NULL) 6717 continue; 6718 rtld_fdprintf(STDOUT_FILENO, "%s:\t", fmt->name); 6719 if (is_ptr_fmt(fmt->fmt)) { 6720 rtld_fdprintfx(STDOUT_FILENO, fmt->fmt, 6721 auxp->a_un.a_ptr); 6722 } else { 6723 rtld_fdprintfx(STDOUT_FILENO, fmt->fmt, 6724 auxp->a_un.a_val); 6725 } 6726 rtld_fdprintf(STDOUT_FILENO, "\n"); 6727 } 6728 } 6729 6730 const char * 6731 rtld_get_var(const char *name) 6732 { 6733 const struct ld_env_var_desc *lvd; 6734 u_int i; 6735 6736 for (i = 0; i < nitems(ld_env_vars); i++) { 6737 lvd = &ld_env_vars[i]; 6738 if (strcmp(lvd->n, name) == 0) 6739 return (lvd->val); 6740 } 6741 return (NULL); 6742 } 6743 6744 static void 6745 rtld_recalc_dangerous_ld_env(void) 6746 { 6747 /* 6748 * Never reset dangerous_ld_env back to false if rtld was ever 6749 * contaminated with it set to true. 6750 */ 6751 dangerous_ld_env |= libmap_disable || libmap_override != NULL || 6752 ld_library_path != NULL || ld_preload != NULL || 6753 ld_elf_hints_path != NULL || ld_loadfltr || !ld_dynamic_weak || 6754 ld_get_env_var(LD_STATIC_TLS_EXTRA) != NULL; 6755 } 6756 6757 static void 6758 rtld_recalc_debug(const char *ld_debug) 6759 { 6760 if (ld_debug != NULL && *ld_debug != '\0') 6761 debug = 1; 6762 } 6763 6764 static void 6765 rtld_set_var_debug(struct ld_env_var_desc *lvd) 6766 { 6767 rtld_recalc_debug(lvd->val); 6768 } 6769 6770 static void 6771 rtld_set_var_library_path(struct ld_env_var_desc *lvd) 6772 { 6773 ld_library_path = lvd->val; 6774 } 6775 6776 static void 6777 rtld_set_var_library_path_fds(struct ld_env_var_desc *lvd) 6778 { 6779 ld_library_dirs = lvd->val; 6780 } 6781 6782 static void 6783 rtld_recalc_path_rpath(const char *library_path_rpath) 6784 { 6785 if (library_path_rpath != NULL) { 6786 if (library_path_rpath[0] == 'y' || 6787 library_path_rpath[0] == 'Y' || 6788 library_path_rpath[0] == '1') 6789 ld_library_path_rpath = true; 6790 else 6791 ld_library_path_rpath = false; 6792 } else { 6793 ld_library_path_rpath = false; 6794 } 6795 } 6796 6797 static void 6798 rtld_set_var_library_path_rpath(struct ld_env_var_desc *lvd) 6799 { 6800 rtld_recalc_path_rpath(lvd->val); 6801 } 6802 6803 static void 6804 rtld_recalc_bind_not(const char *bind_not_val) 6805 { 6806 if (ld_bind_now == NULL) 6807 ld_bind_not = bind_not_val != NULL; 6808 } 6809 6810 static void 6811 rtld_set_var_bind_now(struct ld_env_var_desc *lvd) 6812 { 6813 ld_bind_now = lvd->val; 6814 rtld_recalc_bind_not(ld_get_env_var(LD_BIND_NOT)); 6815 } 6816 6817 static void 6818 rtld_set_var_bind_not(struct ld_env_var_desc *lvd) 6819 { 6820 rtld_recalc_bind_not(lvd->val); 6821 } 6822 6823 static void 6824 rtld_set_var_dynamic_weak(struct ld_env_var_desc *lvd) 6825 { 6826 ld_dynamic_weak = lvd->val == NULL; 6827 } 6828 6829 static void 6830 rtld_set_var_loadfltr(struct ld_env_var_desc *lvd) 6831 { 6832 ld_loadfltr = lvd->val != NULL; 6833 } 6834 6835 static void 6836 rtld_set_var_libmap_disable(struct ld_env_var_desc *lvd) 6837 { 6838 libmap_disable = lvd->val != NULL; 6839 } 6840 6841 int 6842 rtld_set_var(const char *name, const char *val) 6843 { 6844 RtldLockState lockstate; 6845 struct ld_env_var_desc *lvd; 6846 u_int i; 6847 int error; 6848 6849 error = ENOENT; 6850 wlock_acquire(rtld_bind_lock, &lockstate); 6851 for (i = 0; i < nitems(ld_env_vars); i++) { 6852 lvd = &ld_env_vars[i]; 6853 if (strcmp(lvd->n, name) != 0) 6854 continue; 6855 if (!lvd->can_update || (lvd->unsecure && !trust)) { 6856 error = EPERM; 6857 break; 6858 } 6859 if (lvd->owned) 6860 free(__DECONST(char *, lvd->val)); 6861 if (val != NULL) 6862 lvd->val = xstrdup(val); 6863 else 6864 lvd->val = NULL; 6865 lvd->owned = true; 6866 if (lvd->on_update != NULL) 6867 lvd->on_update(lvd); 6868 error = 0; 6869 break; 6870 } 6871 if (error == 0) 6872 rtld_recalc_dangerous_ld_env(); 6873 lock_release(rtld_bind_lock, &lockstate); 6874 return (error); 6875 } 6876 6877 /* 6878 * Overrides for libc_pic-provided functions. 6879 */ 6880 6881 int 6882 __getosreldate(void) 6883 { 6884 size_t len; 6885 int oid[2]; 6886 int error, osrel; 6887 6888 if (osreldate != 0) 6889 return (osreldate); 6890 6891 oid[0] = CTL_KERN; 6892 oid[1] = KERN_OSRELDATE; 6893 osrel = 0; 6894 len = sizeof(osrel); 6895 error = sysctl(oid, 2, &osrel, &len, NULL, 0); 6896 if (error == 0 && osrel > 0 && len == sizeof(osrel)) 6897 osreldate = osrel; 6898 return (osreldate); 6899 } 6900 const char * 6901 rtld_strerror(int errnum) 6902 { 6903 if (errnum < 0 || errnum >= sys_nerr) 6904 return ("Unknown error"); 6905 return (sys_errlist[errnum]); 6906 } 6907 6908 char * 6909 getenv(const char *name) 6910 { 6911 return (__DECONST(char *, rtld_get_env_val(environ, name, 6912 strlen(name)))); 6913 } 6914 6915 extern int _rtld_version__FreeBSD_version __exported; 6916 int _rtld_version__FreeBSD_version = __FreeBSD_version; 6917 6918 extern char _rtld_version_laddr_offset __exported; 6919 char _rtld_version_laddr_offset; 6920 6921 extern char _rtld_version_dlpi_tls_data __exported; 6922 char _rtld_version_dlpi_tls_data; 6923