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(RtldLockState *lockstate); 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(&lockstate); 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 if (ph->p_memsz < ph->p_filesz) { 1752 _rtld_error("%s: invalid PT_TLS segment", 1753 path); 1754 return (NULL); 1755 } 1756 1757 obj->tlsindex = 1; 1758 obj->tlssize = ph->p_memsz; 1759 obj->tlsalign = ph->p_align; 1760 obj->tlsinitsize = ph->p_filesz; 1761 obj->tlsinit = (void *)(ph->p_vaddr + obj->relocbase); 1762 obj->tlspoffset = ph->p_offset; 1763 break; 1764 1765 case PT_GNU_STACK: 1766 obj->stack_flags = ph->p_flags; 1767 break; 1768 1769 case PT_NOTE: 1770 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; 1771 note_end = note_start + ph->p_filesz; 1772 digest_notes(obj, note_start, note_end); 1773 break; 1774 } 1775 } 1776 if (nsegs < 1) { 1777 _rtld_error("%s: too few PT_LOAD segments", path); 1778 return (NULL); 1779 } 1780 1781 obj->entry = entry; 1782 return (obj); 1783 } 1784 1785 void 1786 digest_notes(Obj_Entry *obj, Elf_Addr note_start, Elf_Addr note_end) 1787 { 1788 const Elf_Note *note, *next_note; 1789 const char *note_name; 1790 uintptr_t p; 1791 1792 for (note = (const Elf_Note *)note_start;; note = next_note) { 1793 if ((Elf_Addr)note + sizeof(Elf_Note) > note_end) 1794 break; 1795 next_note = (const Elf_Note *)((const char *)(note + 1) + 1796 roundup2(note->n_namesz, sizeof(Elf32_Addr)) + 1797 roundup2(note->n_descsz, sizeof(Elf32_Addr))); 1798 if ((Elf_Addr)next_note > note_end) 1799 break; 1800 1801 if (arch_digest_note(obj, note)) 1802 continue; 1803 1804 if (note->n_namesz != sizeof(NOTE_FREEBSD_VENDOR) || 1805 note->n_descsz != sizeof(int32_t)) 1806 continue; 1807 if (note->n_type != NT_FREEBSD_ABI_TAG && 1808 note->n_type != NT_FREEBSD_FEATURE_CTL && 1809 note->n_type != NT_FREEBSD_NOINIT_TAG) 1810 continue; 1811 note_name = (const char *)(note + 1); 1812 if (strncmp(NOTE_FREEBSD_VENDOR, note_name, 1813 sizeof(NOTE_FREEBSD_VENDOR)) != 0) 1814 continue; 1815 switch (note->n_type) { 1816 case NT_FREEBSD_ABI_TAG: 1817 /* FreeBSD osrel note */ 1818 p = (uintptr_t)(note + 1); 1819 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1820 obj->osrel = *(const int32_t *)(p); 1821 dbg("note osrel %d", obj->osrel); 1822 break; 1823 case NT_FREEBSD_FEATURE_CTL: 1824 /* FreeBSD ABI feature control note */ 1825 p = (uintptr_t)(note + 1); 1826 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1827 obj->fctl0 = *(const uint32_t *)(p); 1828 dbg("note fctl0 %#x", obj->fctl0); 1829 break; 1830 case NT_FREEBSD_NOINIT_TAG: 1831 /* FreeBSD 'crt does not call init' note */ 1832 obj->crt_no_init = true; 1833 dbg("note crt_no_init"); 1834 break; 1835 } 1836 } 1837 } 1838 1839 static Obj_Entry * 1840 dlcheck(void *handle) 1841 { 1842 Obj_Entry *obj; 1843 1844 TAILQ_FOREACH(obj, &obj_list, next) { 1845 if (obj == (Obj_Entry *)handle) 1846 break; 1847 } 1848 1849 if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) { 1850 _rtld_error("Invalid shared object handle %p", handle); 1851 return (NULL); 1852 } 1853 return (obj); 1854 } 1855 1856 /* 1857 * If the given object is already in the donelist, return true. Otherwise 1858 * add the object to the list and return false. 1859 */ 1860 static bool 1861 donelist_check(DoneList *dlp, const Obj_Entry *obj) 1862 { 1863 unsigned int i; 1864 1865 for (i = 0; i < dlp->num_used; i++) 1866 if (dlp->objs[i] == obj) 1867 return (true); 1868 /* 1869 * Our donelist allocation should always be sufficient. But if 1870 * our threads locking isn't working properly, more shared objects 1871 * could have been loaded since we allocated the list. That should 1872 * never happen, but we'll handle it properly just in case it does. 1873 */ 1874 if (dlp->num_used < dlp->num_alloc) 1875 dlp->objs[dlp->num_used++] = obj; 1876 return (false); 1877 } 1878 1879 /* 1880 * SysV hash function for symbol table lookup. It is a slightly optimized 1881 * version of the hash specified by the System V ABI. 1882 */ 1883 Elf32_Word 1884 elf_hash(const char *name) 1885 { 1886 const unsigned char *p = (const unsigned char *)name; 1887 Elf32_Word h = 0; 1888 1889 while (*p != '\0') { 1890 h = (h << 4) + *p++; 1891 h ^= (h >> 24) & 0xf0; 1892 } 1893 return (h & 0x0fffffff); 1894 } 1895 1896 /* 1897 * The GNU hash function is the Daniel J. Bernstein hash clipped to 32 bits 1898 * unsigned in case it's implemented with a wider type. 1899 */ 1900 static uint32_t 1901 gnu_hash(const char *s) 1902 { 1903 uint32_t h; 1904 unsigned char c; 1905 1906 h = 5381; 1907 for (c = *s; c != '\0'; c = *++s) 1908 h = h * 33 + c; 1909 return (h & 0xffffffff); 1910 } 1911 1912 /* 1913 * Find the library with the given name, and return its full pathname. 1914 * The returned string is dynamically allocated. Generates an error 1915 * message and returns NULL if the library cannot be found. 1916 * 1917 * If the second argument is non-NULL, then it refers to an already- 1918 * loaded shared object, whose library search path will be searched. 1919 * 1920 * If a library is successfully located via LD_LIBRARY_PATH_FDS, its 1921 * descriptor (which is close-on-exec) will be passed out via the third 1922 * argument. 1923 * 1924 * The search order is: 1925 * DT_RPATH in the referencing file _unless_ DT_RUNPATH is present (1) 1926 * DT_RPATH of the main object if DSO without defined DT_RUNPATH (1) 1927 * LD_LIBRARY_PATH 1928 * DT_RUNPATH in the referencing file 1929 * ldconfig hints (if -z nodefaultlib, filter out default library directories 1930 * from list) 1931 * /lib:/usr/lib _unless_ the referencing file is linked with -z nodefaultlib 1932 * 1933 * (1) Handled in digest_dynamic2 - rpath left NULL if runpath defined. 1934 */ 1935 static char * 1936 find_library(const char *xname, const Obj_Entry *refobj, int *fdp) 1937 { 1938 char *pathname, *refobj_path; 1939 const char *name; 1940 bool nodeflib, objgiven; 1941 1942 objgiven = refobj != NULL; 1943 1944 if (libmap_disable || !objgiven || 1945 (name = lm_find(refobj->path, xname)) == NULL) 1946 name = xname; 1947 1948 if (strchr(name, '/') != NULL) { /* Hard coded pathname */ 1949 if (name[0] != '/' && !trust) { 1950 _rtld_error( 1951 "Absolute pathname required for shared object \"%s\"", 1952 name); 1953 return (NULL); 1954 } 1955 return (origin_subst(__DECONST(Obj_Entry *, refobj), 1956 __DECONST(char *, name))); 1957 } 1958 1959 dbg(" Searching for \"%s\"", name); 1960 refobj_path = objgiven ? refobj->path : NULL; 1961 1962 /* 1963 * If refobj->rpath != NULL, then refobj->runpath is NULL. Fall 1964 * back to pre-conforming behaviour if user requested so with 1965 * LD_LIBRARY_PATH_RPATH environment variable and ignore -z 1966 * nodeflib. 1967 */ 1968 if (objgiven && refobj->rpath != NULL && ld_library_path_rpath) { 1969 pathname = search_library_path(name, ld_library_path, 1970 refobj_path, fdp); 1971 if (pathname != NULL) 1972 return (pathname); 1973 if (refobj != NULL) { 1974 pathname = search_library_path(name, refobj->rpath, 1975 refobj_path, fdp); 1976 if (pathname != NULL) 1977 return (pathname); 1978 } 1979 pathname = search_library_pathfds(name, ld_library_dirs, fdp); 1980 if (pathname != NULL) 1981 return (pathname); 1982 pathname = search_library_path(name, gethints(false), 1983 refobj_path, fdp); 1984 if (pathname != NULL) 1985 return (pathname); 1986 pathname = search_library_path(name, ld_standard_library_path, 1987 refobj_path, fdp); 1988 if (pathname != NULL) 1989 return (pathname); 1990 } else { 1991 nodeflib = objgiven ? refobj->z_nodeflib : false; 1992 if (objgiven) { 1993 pathname = search_library_path(name, refobj->rpath, 1994 refobj->path, fdp); 1995 if (pathname != NULL) 1996 return (pathname); 1997 } 1998 if (objgiven && refobj->runpath == NULL && refobj != obj_main) { 1999 pathname = search_library_path(name, obj_main->rpath, 2000 refobj_path, fdp); 2001 if (pathname != NULL) 2002 return (pathname); 2003 } 2004 pathname = search_library_path(name, ld_library_path, 2005 refobj_path, fdp); 2006 if (pathname != NULL) 2007 return (pathname); 2008 if (objgiven) { 2009 pathname = search_library_path(name, refobj->runpath, 2010 refobj_path, fdp); 2011 if (pathname != NULL) 2012 return (pathname); 2013 } 2014 pathname = search_library_pathfds(name, ld_library_dirs, fdp); 2015 if (pathname != NULL) 2016 return (pathname); 2017 pathname = search_library_path(name, gethints(nodeflib), 2018 refobj_path, fdp); 2019 if (pathname != NULL) 2020 return (pathname); 2021 if (objgiven && !nodeflib) { 2022 pathname = search_library_path(name, 2023 ld_standard_library_path, refobj_path, fdp); 2024 if (pathname != NULL) 2025 return (pathname); 2026 } 2027 } 2028 2029 if (objgiven && refobj->path != NULL) { 2030 _rtld_error( 2031 "Shared object \"%s\" not found, required by \"%s\"", 2032 name, basename(refobj->path)); 2033 } else { 2034 _rtld_error("Shared object \"%s\" not found", name); 2035 } 2036 return (NULL); 2037 } 2038 2039 /* 2040 * Given a symbol number in a referencing object, find the corresponding 2041 * definition of the symbol. Returns a pointer to the symbol, or NULL if 2042 * no definition was found. Returns a pointer to the Obj_Entry of the 2043 * defining object via the reference parameter DEFOBJ_OUT. 2044 */ 2045 const Elf_Sym * 2046 find_symdef(unsigned long symnum, const Obj_Entry *refobj, 2047 const Obj_Entry **defobj_out, int flags, SymCache *cache, 2048 RtldLockState *lockstate) 2049 { 2050 const Elf_Sym *ref; 2051 const Elf_Sym *def; 2052 const Obj_Entry *defobj; 2053 const Ver_Entry *ve; 2054 SymLook req; 2055 const char *name; 2056 int res; 2057 2058 /* 2059 * If we have already found this symbol, get the information from 2060 * the cache. 2061 */ 2062 if (symnum >= refobj->dynsymcount) 2063 return (NULL); /* Bad object */ 2064 if (cache != NULL && cache[symnum].sym != NULL) { 2065 *defobj_out = cache[symnum].obj; 2066 return (cache[symnum].sym); 2067 } 2068 2069 ref = refobj->symtab + symnum; 2070 name = refobj->strtab + ref->st_name; 2071 def = NULL; 2072 defobj = NULL; 2073 ve = NULL; 2074 2075 /* 2076 * We don't have to do a full scale lookup if the symbol is local. 2077 * We know it will bind to the instance in this load module; to 2078 * which we already have a pointer (ie ref). By not doing a lookup, 2079 * we not only improve performance, but it also avoids unresolvable 2080 * symbols when local symbols are not in the hash table. This has 2081 * been seen with the ia64 toolchain. 2082 */ 2083 if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) { 2084 if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) { 2085 _rtld_error("%s: Bogus symbol table entry %lu", 2086 refobj->path, symnum); 2087 } 2088 symlook_init(&req, name); 2089 req.flags = flags; 2090 ve = req.ventry = fetch_ventry(refobj, symnum); 2091 req.lockstate = lockstate; 2092 res = symlook_default(&req, refobj); 2093 if (res == 0) { 2094 def = req.sym_out; 2095 defobj = req.defobj_out; 2096 } 2097 } else { 2098 def = ref; 2099 defobj = refobj; 2100 } 2101 2102 /* 2103 * If we found no definition and the reference is weak, treat the 2104 * symbol as having the value zero. 2105 */ 2106 if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) { 2107 def = &sym_zero; 2108 defobj = obj_main; 2109 } 2110 2111 if (def != NULL) { 2112 *defobj_out = defobj; 2113 /* 2114 * Record the information in the cache to avoid subsequent 2115 * lookups. 2116 */ 2117 if (cache != NULL) { 2118 cache[symnum].sym = def; 2119 cache[symnum].obj = defobj; 2120 } 2121 } else { 2122 if (refobj != &obj_rtld) 2123 _rtld_error("%s: Undefined symbol \"%s%s%s\"", 2124 refobj->path, name, ve != NULL ? "@" : "", 2125 ve != NULL ? ve->name : ""); 2126 } 2127 return (def); 2128 } 2129 2130 /* Convert between native byte order and forced little resp. big endian. */ 2131 #define COND_SWAP(n) (is_le ? le32toh(n) : be32toh(n)) 2132 2133 /* 2134 * Return the search path from the ldconfig hints file, reading it if 2135 * necessary. If nostdlib is true, then the default search paths are 2136 * not added to result. 2137 * 2138 * Returns NULL if there are problems with the hints file, 2139 * or if the search path there is empty. 2140 */ 2141 static const char * 2142 gethints(bool nostdlib) 2143 { 2144 static char *filtered_path; 2145 static const char *hints; 2146 static struct elfhints_hdr hdr; 2147 struct fill_search_info_args sargs, hargs; 2148 struct dl_serinfo smeta, hmeta, *SLPinfo, *hintinfo; 2149 struct dl_serpath *SLPpath, *hintpath; 2150 char *p; 2151 struct stat hint_stat; 2152 unsigned int SLPndx, hintndx, fndx, fcount; 2153 int fd; 2154 size_t flen; 2155 uint32_t dl; 2156 uint32_t magic; /* Magic number */ 2157 uint32_t version; /* File version (1) */ 2158 uint32_t strtab; /* Offset of string table in file */ 2159 uint32_t dirlist; /* Offset of directory list in string table */ 2160 uint32_t dirlistlen; /* strlen(dirlist) */ 2161 bool is_le; /* Does the hints file use little endian */ 2162 bool skip; 2163 2164 /* First call, read the hints file */ 2165 if (hints == NULL) { 2166 /* Keep from trying again in case the hints file is bad. */ 2167 hints = ""; 2168 2169 if ((fd = open(ld_elf_hints_path, O_RDONLY | O_CLOEXEC)) == 2170 -1) { 2171 dbg("failed to open hints file \"%s\"", 2172 ld_elf_hints_path); 2173 return (NULL); 2174 } 2175 2176 /* 2177 * Check of hdr.dirlistlen value against type limit 2178 * intends to pacify static analyzers. Further 2179 * paranoia leads to checks that dirlist is fully 2180 * contained in the file range. 2181 */ 2182 if (read(fd, &hdr, sizeof hdr) != sizeof hdr) { 2183 dbg("failed to read %lu bytes from hints file \"%s\"", 2184 (u_long)sizeof hdr, ld_elf_hints_path); 2185 cleanup1: 2186 close(fd); 2187 hdr.dirlistlen = 0; 2188 return (NULL); 2189 } 2190 dbg("host byte-order: %s-endian", 2191 le32toh(1) == 1 ? "little" : "big"); 2192 dbg("hints file byte-order: %s-endian", 2193 hdr.magic == htole32(ELFHINTS_MAGIC) ? "little" : "big"); 2194 is_le = /*htole32(1) == 1 || */ hdr.magic == 2195 htole32(ELFHINTS_MAGIC); 2196 magic = COND_SWAP(hdr.magic); 2197 version = COND_SWAP(hdr.version); 2198 strtab = COND_SWAP(hdr.strtab); 2199 dirlist = COND_SWAP(hdr.dirlist); 2200 dirlistlen = COND_SWAP(hdr.dirlistlen); 2201 if (magic != ELFHINTS_MAGIC) { 2202 dbg("invalid magic number %#08x (expected: %#08x)", 2203 magic, ELFHINTS_MAGIC); 2204 goto cleanup1; 2205 } 2206 if (version != 1) { 2207 dbg("hints file version %d (expected: 1)", version); 2208 goto cleanup1; 2209 } 2210 if (dirlistlen > UINT_MAX / 2) { 2211 dbg("directory list is to long: %d > %d", dirlistlen, 2212 UINT_MAX / 2); 2213 goto cleanup1; 2214 } 2215 if (fstat(fd, &hint_stat) == -1) { 2216 dbg("failed to find length of hints file \"%s\"", 2217 ld_elf_hints_path); 2218 goto cleanup1; 2219 } 2220 dl = strtab; 2221 if (dl + dirlist < dl) { 2222 dbg("invalid string table position %d", dl); 2223 goto cleanup1; 2224 } 2225 dl += dirlist; 2226 if (dl + dirlistlen < dl) { 2227 dbg("invalid directory list offset %d", dirlist); 2228 goto cleanup1; 2229 } 2230 dl += dirlistlen; 2231 if (dl > hint_stat.st_size) { 2232 dbg("hints file \"%s\" is truncated (%d vs. %jd bytes)", 2233 ld_elf_hints_path, dl, 2234 (uintmax_t)hint_stat.st_size); 2235 goto cleanup1; 2236 } 2237 p = xmalloc(dirlistlen + 1); 2238 if (pread(fd, p, dirlistlen + 1, strtab + dirlist) != 2239 (ssize_t)dirlistlen + 1 || p[dirlistlen] != '\0') { 2240 free(p); 2241 dbg( 2242 "failed to read %d bytes starting at %d from hints file \"%s\"", 2243 dirlistlen + 1, strtab + dirlist, 2244 ld_elf_hints_path); 2245 goto cleanup1; 2246 } 2247 hints = p; 2248 close(fd); 2249 } 2250 2251 /* 2252 * If caller agreed to receive list which includes the default 2253 * paths, we are done. Otherwise, if we still did not 2254 * calculated filtered result, do it now. 2255 */ 2256 if (!nostdlib) 2257 return (hints[0] != '\0' ? hints : NULL); 2258 if (filtered_path != NULL) 2259 goto filt_ret; 2260 2261 /* 2262 * Obtain the list of all configured search paths, and the 2263 * list of the default paths. 2264 * 2265 * First estimate the size of the results. 2266 */ 2267 smeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 2268 smeta.dls_cnt = 0; 2269 hmeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 2270 hmeta.dls_cnt = 0; 2271 2272 sargs.request = RTLD_DI_SERINFOSIZE; 2273 sargs.serinfo = &smeta; 2274 hargs.request = RTLD_DI_SERINFOSIZE; 2275 hargs.serinfo = &hmeta; 2276 2277 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 2278 &sargs); 2279 path_enumerate(hints, fill_search_info, NULL, &hargs); 2280 2281 SLPinfo = xmalloc(smeta.dls_size); 2282 hintinfo = xmalloc(hmeta.dls_size); 2283 2284 /* 2285 * Next fetch both sets of paths. 2286 */ 2287 sargs.request = RTLD_DI_SERINFO; 2288 sargs.serinfo = SLPinfo; 2289 sargs.serpath = &SLPinfo->dls_serpath[0]; 2290 sargs.strspace = (char *)&SLPinfo->dls_serpath[smeta.dls_cnt]; 2291 2292 hargs.request = RTLD_DI_SERINFO; 2293 hargs.serinfo = hintinfo; 2294 hargs.serpath = &hintinfo->dls_serpath[0]; 2295 hargs.strspace = (char *)&hintinfo->dls_serpath[hmeta.dls_cnt]; 2296 2297 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 2298 &sargs); 2299 path_enumerate(hints, fill_search_info, NULL, &hargs); 2300 2301 /* 2302 * Now calculate the difference between two sets, by excluding 2303 * standard paths from the full set. 2304 */ 2305 fndx = 0; 2306 fcount = 0; 2307 filtered_path = xmalloc(dirlistlen + 1); 2308 hintpath = &hintinfo->dls_serpath[0]; 2309 for (hintndx = 0; hintndx < hmeta.dls_cnt; hintndx++, hintpath++) { 2310 skip = false; 2311 SLPpath = &SLPinfo->dls_serpath[0]; 2312 /* 2313 * Check each standard path against current. 2314 */ 2315 for (SLPndx = 0; SLPndx < smeta.dls_cnt; SLPndx++, SLPpath++) { 2316 /* matched, skip the path */ 2317 if (!strcmp(hintpath->dls_name, SLPpath->dls_name)) { 2318 skip = true; 2319 break; 2320 } 2321 } 2322 if (skip) 2323 continue; 2324 /* 2325 * Not matched against any standard path, add the path 2326 * to result. Separate consequtive paths with ':'. 2327 */ 2328 if (fcount > 0) { 2329 filtered_path[fndx] = ':'; 2330 fndx++; 2331 } 2332 fcount++; 2333 flen = strlen(hintpath->dls_name); 2334 strncpy((filtered_path + fndx), hintpath->dls_name, flen); 2335 fndx += flen; 2336 } 2337 filtered_path[fndx] = '\0'; 2338 2339 free(SLPinfo); 2340 free(hintinfo); 2341 2342 filt_ret: 2343 return (filtered_path[0] != '\0' ? filtered_path : NULL); 2344 } 2345 2346 static void 2347 init_dag(Obj_Entry *root) 2348 { 2349 const Needed_Entry *needed; 2350 const Objlist_Entry *elm; 2351 DoneList donelist; 2352 2353 if (root->dag_inited) 2354 return; 2355 donelist_init(&donelist, NULL); 2356 2357 /* Root object belongs to own DAG. */ 2358 objlist_push_tail(&root->dldags, root); 2359 objlist_push_tail(&root->dagmembers, root); 2360 donelist_check(&donelist, root); 2361 2362 /* 2363 * Add dependencies of root object to DAG in breadth order 2364 * by exploiting the fact that each new object get added 2365 * to the tail of the dagmembers list. 2366 */ 2367 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2368 for (needed = elm->obj->needed; needed != NULL; 2369 needed = needed->next) { 2370 if (needed->obj == NULL || 2371 donelist_check(&donelist, needed->obj)) 2372 continue; 2373 objlist_push_tail(&needed->obj->dldags, root); 2374 objlist_push_tail(&root->dagmembers, needed->obj); 2375 } 2376 } 2377 root->dag_inited = true; 2378 donelist_free(&donelist); 2379 } 2380 2381 static void 2382 init_marker(Obj_Entry *marker) 2383 { 2384 bzero(marker, sizeof(*marker)); 2385 marker->marker = true; 2386 } 2387 2388 Obj_Entry * 2389 globallist_curr(const Obj_Entry *obj) 2390 { 2391 for (;;) { 2392 if (obj == NULL) 2393 return (NULL); 2394 if (!obj->marker) 2395 return (__DECONST(Obj_Entry *, obj)); 2396 obj = TAILQ_PREV(obj, obj_entry_q, next); 2397 } 2398 } 2399 2400 Obj_Entry * 2401 globallist_next(const Obj_Entry *obj) 2402 { 2403 for (;;) { 2404 obj = TAILQ_NEXT(obj, next); 2405 if (obj == NULL) 2406 return (NULL); 2407 if (!obj->marker) 2408 return (__DECONST(Obj_Entry *, obj)); 2409 } 2410 } 2411 2412 /* Prevent the object from being unmapped while the bind lock is dropped. */ 2413 static void 2414 hold_object(Obj_Entry *obj) 2415 { 2416 obj->holdcount++; 2417 } 2418 2419 static void 2420 unhold_object(Obj_Entry *obj) 2421 { 2422 assert(obj->holdcount > 0); 2423 if (--obj->holdcount == 0 && obj->unholdfree) 2424 release_object(obj); 2425 } 2426 2427 static void 2428 process_z(Obj_Entry *root) 2429 { 2430 const Objlist_Entry *elm; 2431 Obj_Entry *obj; 2432 2433 /* 2434 * Walk over object DAG and process every dependent object 2435 * that is marked as DF_1_NODELETE or DF_1_GLOBAL. They need 2436 * to grow their own DAG. 2437 * 2438 * For DF_1_GLOBAL, DAG is required for symbol lookups in 2439 * symlook_global() to work. 2440 * 2441 * For DF_1_NODELETE, the DAG should have its reference upped. 2442 */ 2443 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2444 obj = elm->obj; 2445 if (obj == NULL) 2446 continue; 2447 if (obj->z_nodelete && !obj->ref_nodel) { 2448 dbg("obj %s -z nodelete", obj->path); 2449 init_dag(obj); 2450 ref_dag(obj); 2451 obj->ref_nodel = true; 2452 } 2453 if (obj->z_global && objlist_find(&list_global, obj) == NULL) { 2454 dbg("obj %s -z global", obj->path); 2455 objlist_push_tail(&list_global, obj); 2456 init_dag(obj); 2457 } 2458 } 2459 } 2460 2461 static void 2462 parse_rtld_phdr(Obj_Entry *obj) 2463 { 2464 const Elf_Phdr *ph; 2465 Elf_Addr note_start, note_end; 2466 bool first_seg; 2467 2468 first_seg = true; 2469 obj->stack_flags = PF_X | PF_R | PF_W; 2470 for (ph = obj->phdr; ph < obj->phdr + obj->phnum; ph++) { 2471 switch (ph->p_type) { 2472 case PT_LOAD: 2473 if (first_seg) { 2474 obj->vaddrbase = rtld_trunc_page(ph->p_vaddr); 2475 first_seg = false; 2476 } 2477 obj->mapsize = rtld_round_page(ph->p_vaddr + 2478 ph->p_memsz) - obj->vaddrbase; 2479 break; 2480 case PT_GNU_STACK: 2481 obj->stack_flags = ph->p_flags; 2482 break; 2483 case PT_NOTE: 2484 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; 2485 note_end = note_start + ph->p_filesz; 2486 digest_notes(obj, note_start, note_end); 2487 break; 2488 } 2489 } 2490 } 2491 2492 /* 2493 * Initialize the dynamic linker. The argument is the address at which 2494 * the dynamic linker has been mapped into memory. The primary task of 2495 * this function is to relocate the dynamic linker. 2496 */ 2497 static void 2498 init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info) 2499 { 2500 Obj_Entry objtmp; /* Temporary rtld object */ 2501 const Elf_Ehdr *ehdr; 2502 const Elf_Dyn *dyn_rpath; 2503 const Elf_Dyn *dyn_soname; 2504 const Elf_Dyn *dyn_runpath; 2505 2506 /* 2507 * Conjure up an Obj_Entry structure for the dynamic linker. 2508 * 2509 * The "path" member can't be initialized yet because string constants 2510 * cannot yet be accessed. Below we will set it correctly. 2511 */ 2512 memset(&objtmp, 0, sizeof(objtmp)); 2513 objtmp.path = NULL; 2514 objtmp.rtld = true; 2515 objtmp.mapbase = mapbase; 2516 objtmp.relocbase = mapbase; 2517 2518 objtmp.dynamic = rtld_dynamic(&objtmp); 2519 digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname, &dyn_runpath); 2520 assert(objtmp.needed == NULL); 2521 assert(!objtmp.textrel); 2522 /* 2523 * Temporarily put the dynamic linker entry into the object list, so 2524 * that symbols can be found. 2525 */ 2526 relocate_objects(&objtmp, true, &objtmp, 0, NULL); 2527 2528 ehdr = (Elf_Ehdr *)mapbase; 2529 objtmp.phdr = (Elf_Phdr *)((char *)mapbase + ehdr->e_phoff); 2530 objtmp.phnum = ehdr->e_phnum; 2531 2532 /* Initialize the object list. */ 2533 TAILQ_INIT(&obj_list); 2534 2535 /* Now that non-local variables can be accesses, copy out obj_rtld. */ 2536 memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld)); 2537 2538 /* The page size is required by the dynamic memory allocator. */ 2539 init_pagesizes(aux_info); 2540 2541 if (aux_info[AT_OSRELDATE] != NULL) 2542 osreldate = aux_info[AT_OSRELDATE]->a_un.a_val; 2543 2544 digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname, dyn_runpath); 2545 2546 /* Replace the path with a dynamically allocated copy. */ 2547 obj_rtld.path = xstrdup(ld_path_rtld); 2548 2549 parse_rtld_phdr(&obj_rtld); 2550 if (obj_enforce_relro(&obj_rtld) == -1) 2551 rtld_die(); 2552 2553 r_debug.r_version = R_DEBUG_VERSION; 2554 r_debug.r_brk = r_debug_state; 2555 r_debug.r_state = RT_CONSISTENT; 2556 r_debug.r_ldbase = obj_rtld.relocbase; 2557 } 2558 2559 /* 2560 * Retrieve the array of supported page sizes. The kernel provides the page 2561 * sizes in increasing order. 2562 */ 2563 static void 2564 init_pagesizes(Elf_Auxinfo **aux_info) 2565 { 2566 static size_t psa[MAXPAGESIZES]; 2567 int mib[2]; 2568 size_t len, size; 2569 2570 if (aux_info[AT_PAGESIZES] != NULL && 2571 aux_info[AT_PAGESIZESLEN] != NULL) { 2572 size = aux_info[AT_PAGESIZESLEN]->a_un.a_val; 2573 pagesizes = aux_info[AT_PAGESIZES]->a_un.a_ptr; 2574 } else { 2575 len = 2; 2576 if (sysctlnametomib("hw.pagesizes", mib, &len) == 0) 2577 size = sizeof(psa); 2578 else { 2579 /* As a fallback, retrieve the base page size. */ 2580 size = sizeof(psa[0]); 2581 if (aux_info[AT_PAGESZ] != NULL) { 2582 psa[0] = aux_info[AT_PAGESZ]->a_un.a_val; 2583 goto psa_filled; 2584 } else { 2585 mib[0] = CTL_HW; 2586 mib[1] = HW_PAGESIZE; 2587 len = 2; 2588 } 2589 } 2590 if (sysctl(mib, len, psa, &size, NULL, 0) == -1) { 2591 _rtld_error("sysctl for hw.pagesize(s) failed"); 2592 rtld_die(); 2593 } 2594 psa_filled: 2595 pagesizes = psa; 2596 } 2597 npagesizes = size / sizeof(pagesizes[0]); 2598 /* Discard any invalid entries at the end of the array. */ 2599 while (npagesizes > 0 && pagesizes[npagesizes - 1] == 0) 2600 npagesizes--; 2601 2602 page_size = pagesizes[0]; 2603 } 2604 2605 /* 2606 * Add the init functions from a needed object list (and its recursive 2607 * needed objects) to "list". This is not used directly; it is a helper 2608 * function for initlist_add_objects(). The write lock must be held 2609 * when this function is called. 2610 */ 2611 static void 2612 initlist_add_neededs(Needed_Entry *needed, Objlist *list, Objlist *iflist) 2613 { 2614 /* Recursively process the successor needed objects. */ 2615 if (needed->next != NULL) 2616 initlist_add_neededs(needed->next, list, iflist); 2617 2618 /* Process the current needed object. */ 2619 if (needed->obj != NULL) 2620 initlist_add_objects(needed->obj, needed->obj, list, iflist); 2621 } 2622 2623 /* 2624 * Scan all of the DAGs rooted in the range of objects from "obj" to 2625 * "tail" and add their init functions to "list". This recurses over 2626 * the DAGs and ensure the proper init ordering such that each object's 2627 * needed libraries are initialized before the object itself. At the 2628 * same time, this function adds the objects to the global finalization 2629 * list "list_fini" in the opposite order. The write lock must be 2630 * held when this function is called. 2631 */ 2632 static void 2633 initlist_for_loaded_obj(Obj_Entry *obj, Obj_Entry *tail, Objlist *list) 2634 { 2635 Objlist iflist; /* initfirst objs and their needed */ 2636 Objlist_Entry *tmp; 2637 2638 objlist_init(&iflist); 2639 initlist_add_objects(obj, tail, list, &iflist); 2640 2641 STAILQ_FOREACH(tmp, &iflist, link) { 2642 Obj_Entry *tobj = tmp->obj; 2643 2644 if ((tobj->fini != 0 || tobj->fini_array != NULL) && 2645 !tobj->on_fini_list) { 2646 objlist_push_tail(&list_fini, tobj); 2647 tobj->on_fini_list = true; 2648 } 2649 } 2650 2651 /* 2652 * This might result in the same object appearing more 2653 * than once on the init list. objlist_call_init() 2654 * uses obj->init_scanned to avoid dup calls. 2655 */ 2656 STAILQ_REVERSE(&iflist, Struct_Objlist_Entry, link); 2657 STAILQ_FOREACH(tmp, &iflist, link) 2658 objlist_push_head(list, tmp->obj); 2659 2660 objlist_clear(&iflist); 2661 } 2662 2663 static void 2664 initlist_add_objects(Obj_Entry *obj, Obj_Entry *tail, Objlist *list, 2665 Objlist *iflist) 2666 { 2667 Obj_Entry *nobj; 2668 2669 if (obj->init_done) 2670 return; 2671 2672 if (obj->z_initfirst || list == NULL) { 2673 /* 2674 * Ignore obj->init_scanned. The object might indeed 2675 * already be on the init list, but due to being 2676 * needed by an initfirst object, we must put it at 2677 * the head of the init list. obj->init_done protects 2678 * against double-initialization. 2679 */ 2680 if (obj->needed != NULL) 2681 initlist_add_neededs(obj->needed, NULL, iflist); 2682 if (obj->needed_filtees != NULL) 2683 initlist_add_neededs(obj->needed_filtees, NULL, 2684 iflist); 2685 if (obj->needed_aux_filtees != NULL) 2686 initlist_add_neededs(obj->needed_aux_filtees, 2687 NULL, iflist); 2688 objlist_push_tail(iflist, obj); 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 } else { 2695 if (obj->init_scanned) 2696 return; 2697 obj->init_scanned = true; 2698 2699 /* Recursively process the successor objects. */ 2700 nobj = globallist_next(obj); 2701 if (nobj != NULL && obj != tail) 2702 initlist_add_objects(nobj, tail, list, iflist); 2703 2704 /* Recursively process the needed objects. */ 2705 if (obj->needed != NULL) 2706 initlist_add_neededs(obj->needed, list, iflist); 2707 if (obj->needed_filtees != NULL) 2708 initlist_add_neededs(obj->needed_filtees, list, 2709 iflist); 2710 if (obj->needed_aux_filtees != NULL) 2711 initlist_add_neededs(obj->needed_aux_filtees, list, 2712 iflist); 2713 2714 /* Add the object to the init list. */ 2715 objlist_push_tail(list, obj); 2716 2717 /* 2718 * Add the object to the global fini list in the 2719 * reverse order. 2720 */ 2721 if ((obj->fini != 0 || obj->fini_array != NULL) && 2722 !obj->on_fini_list) { 2723 objlist_push_head(&list_fini, obj); 2724 obj->on_fini_list = true; 2725 } 2726 } 2727 } 2728 2729 static void 2730 free_needed_filtees(Needed_Entry *n, RtldLockState *lockstate) 2731 { 2732 Needed_Entry *needed, *needed1; 2733 2734 for (needed = n; needed != NULL; needed = needed->next) { 2735 if (needed->obj != NULL) { 2736 dlclose_locked(needed->obj, lockstate); 2737 needed->obj = NULL; 2738 } 2739 } 2740 for (needed = n; needed != NULL; needed = needed1) { 2741 needed1 = needed->next; 2742 free(needed); 2743 } 2744 } 2745 2746 static void 2747 unload_filtees(Obj_Entry *obj, RtldLockState *lockstate) 2748 { 2749 free_needed_filtees(obj->needed_filtees, lockstate); 2750 obj->needed_filtees = NULL; 2751 free_needed_filtees(obj->needed_aux_filtees, lockstate); 2752 obj->needed_aux_filtees = NULL; 2753 obj->filtees_loaded = false; 2754 } 2755 2756 static void 2757 load_filtee1(Obj_Entry *obj, Needed_Entry *needed, int flags, 2758 RtldLockState *lockstate) 2759 { 2760 for (; needed != NULL; needed = needed->next) { 2761 needed->obj = dlopen_object(obj->strtab + needed->name, -1, obj, 2762 flags, ((ld_loadfltr || obj->z_loadfltr) ? RTLD_NOW : 2763 RTLD_LAZY) | RTLD_LOCAL, lockstate); 2764 } 2765 } 2766 2767 static void 2768 load_filtees(Obj_Entry *obj, int flags, RtldLockState *lockstate) 2769 { 2770 if (obj->filtees_loaded || obj->filtees_loading) 2771 return; 2772 lock_restart_for_upgrade(lockstate); 2773 obj->filtees_loading = true; 2774 load_filtee1(obj, obj->needed_filtees, flags, lockstate); 2775 load_filtee1(obj, obj->needed_aux_filtees, flags, lockstate); 2776 obj->filtees_loaded = true; 2777 obj->filtees_loading = false; 2778 } 2779 2780 static int 2781 process_needed(Obj_Entry *obj, Needed_Entry *needed, int flags) 2782 { 2783 Obj_Entry *obj1; 2784 2785 for (; needed != NULL; needed = needed->next) { 2786 obj1 = needed->obj = load_object(obj->strtab + needed->name, -1, 2787 obj, flags & ~RTLD_LO_NOLOAD); 2788 if (obj1 == NULL && !ld_tracing && 2789 (flags & RTLD_LO_FILTEES) == 0) 2790 return (-1); 2791 } 2792 return (0); 2793 } 2794 2795 /* 2796 * Given a shared object, traverse its list of needed objects, and load 2797 * each of them. Returns 0 on success. Generates an error message and 2798 * returns -1 on failure. 2799 */ 2800 static int 2801 load_needed_objects(Obj_Entry *first, int flags) 2802 { 2803 Obj_Entry *obj; 2804 2805 for (obj = first; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 2806 if (obj->marker) 2807 continue; 2808 if (process_needed(obj, obj->needed, flags) == -1) 2809 return (-1); 2810 } 2811 return (0); 2812 } 2813 2814 static int 2815 load_preload_objects(const char *penv, bool isfd) 2816 { 2817 Obj_Entry *obj; 2818 const char *name; 2819 size_t len; 2820 char savech, *p, *psave; 2821 int fd; 2822 static const char delim[] = " \t:;"; 2823 2824 if (penv == NULL) 2825 return (0); 2826 2827 p = psave = xstrdup(penv); 2828 p += strspn(p, delim); 2829 while (*p != '\0') { 2830 len = strcspn(p, delim); 2831 2832 savech = p[len]; 2833 p[len] = '\0'; 2834 if (isfd) { 2835 name = NULL; 2836 fd = parse_integer(p); 2837 if (fd == -1) { 2838 free(psave); 2839 return (-1); 2840 } 2841 } else { 2842 name = p; 2843 fd = -1; 2844 } 2845 2846 obj = load_object(name, fd, NULL, 0); 2847 if (obj == NULL) { 2848 free(psave); 2849 return (-1); /* XXX - cleanup */ 2850 } 2851 obj->z_interpose = true; 2852 p[len] = savech; 2853 p += len; 2854 p += strspn(p, delim); 2855 } 2856 LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL); 2857 2858 free(psave); 2859 return (0); 2860 } 2861 2862 static const char * 2863 printable_path(const char *path) 2864 { 2865 return (path == NULL ? "<unknown>" : path); 2866 } 2867 2868 /* 2869 * Load a shared object into memory, if it is not already loaded. The 2870 * object may be specified by name or by user-supplied file descriptor 2871 * fd_u. In the later case, the fd_u descriptor is not closed, but its 2872 * duplicate is. 2873 * 2874 * Returns a pointer to the Obj_Entry for the object. Returns NULL 2875 * on failure. 2876 */ 2877 static Obj_Entry * 2878 load_object(const char *name, int fd_u, const Obj_Entry *refobj, int flags) 2879 { 2880 Obj_Entry *obj; 2881 int fd; 2882 struct stat sb; 2883 char *path; 2884 2885 fd = -1; 2886 if (name != NULL) { 2887 TAILQ_FOREACH(obj, &obj_list, next) { 2888 if (obj->marker || obj->doomed) 2889 continue; 2890 if (object_match_name(obj, name)) 2891 return (obj); 2892 } 2893 2894 path = find_library(name, refobj, &fd); 2895 if (path == NULL) 2896 return (NULL); 2897 } else 2898 path = NULL; 2899 2900 if (fd >= 0) { 2901 /* 2902 * search_library_pathfds() opens a fresh file descriptor for 2903 * the library, so there is no need to dup(). 2904 */ 2905 } else if (fd_u == -1) { 2906 /* 2907 * If we didn't find a match by pathname, or the name is not 2908 * supplied, open the file and check again by device and inode. 2909 * This avoids false mismatches caused by multiple links or ".." 2910 * in pathnames. 2911 * 2912 * To avoid a race, we open the file and use fstat() rather than 2913 * using stat(). 2914 */ 2915 if ((fd = open(path, O_RDONLY | O_CLOEXEC | O_VERIFY)) == -1) { 2916 fd = try_fds_open(path, ld_library_dirs); 2917 if (fd == -1) { 2918 _rtld_error("Cannot open \"%s\"", path); 2919 free(path); 2920 return (NULL); 2921 } 2922 } 2923 } else { 2924 fd = fcntl(fd_u, F_DUPFD_CLOEXEC, 0); 2925 if (fd == -1) { 2926 _rtld_error("Cannot dup fd"); 2927 free(path); 2928 return (NULL); 2929 } 2930 } 2931 if (fstat(fd, &sb) == -1) { 2932 _rtld_error("Cannot fstat \"%s\"", printable_path(path)); 2933 close(fd); 2934 free(path); 2935 return (NULL); 2936 } 2937 TAILQ_FOREACH(obj, &obj_list, next) { 2938 if (obj->marker || obj->doomed) 2939 continue; 2940 if (obj->ino == sb.st_ino && obj->dev == sb.st_dev) 2941 break; 2942 } 2943 if (obj != NULL) { 2944 if (name != NULL) 2945 object_add_name(obj, name); 2946 free(path); 2947 close(fd); 2948 return (obj); 2949 } 2950 if (flags & RTLD_LO_NOLOAD) { 2951 free(path); 2952 close(fd); 2953 return (NULL); 2954 } 2955 2956 /* First use of this object, so we must map it in */ 2957 obj = do_load_object(fd, name, path, &sb, flags); 2958 if (obj == NULL) 2959 free(path); 2960 close(fd); 2961 2962 return (obj); 2963 } 2964 2965 static Obj_Entry * 2966 do_load_object(int fd, const char *name, char *path, struct stat *sbp, 2967 int flags) 2968 { 2969 Obj_Entry *obj; 2970 struct statfs fs; 2971 2972 /* 2973 * First, make sure that environment variables haven't been 2974 * used to circumvent the noexec flag on a filesystem. 2975 * We ignore fstatfs(2) failures, since fd might reference 2976 * not a file, e.g. shmfd. 2977 */ 2978 if (dangerous_ld_env && fstatfs(fd, &fs) == 0 && 2979 (fs.f_flags & MNT_NOEXEC) != 0) { 2980 _rtld_error("Cannot execute objects on %s", fs.f_mntonname); 2981 return (NULL); 2982 } 2983 2984 dbg("loading \"%s\"", printable_path(path)); 2985 obj = map_object(fd, printable_path(path), sbp, false); 2986 if (obj == NULL) 2987 return (NULL); 2988 2989 /* 2990 * If DT_SONAME is present in the object, digest_dynamic2 already 2991 * added it to the object names. 2992 */ 2993 if (name != NULL) 2994 object_add_name(obj, name); 2995 obj->path = path; 2996 if (!digest_dynamic(obj, 0)) 2997 goto errp; 2998 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", obj->path, 2999 obj->valid_hash_sysv, obj->valid_hash_gnu, obj->dynsymcount); 3000 if (obj->z_pie && (flags & RTLD_LO_TRACE) == 0) { 3001 dbg("refusing to load PIE executable \"%s\"", obj->path); 3002 _rtld_error("Cannot load PIE binary %s as DSO", obj->path); 3003 goto errp; 3004 } 3005 if (obj->z_noopen && 3006 (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) == RTLD_LO_DLOPEN) { 3007 dbg("refusing to load non-loadable \"%s\"", obj->path); 3008 _rtld_error("Cannot dlopen non-loadable %s", obj->path); 3009 goto errp; 3010 } 3011 3012 obj->dlopened = (flags & RTLD_LO_DLOPEN) != 0; 3013 TAILQ_INSERT_TAIL(&obj_list, obj, next); 3014 obj_count++; 3015 obj_loads++; 3016 linkmap_add(obj); /* for GDB & dlinfo() */ 3017 max_stack_flags |= obj->stack_flags; 3018 3019 dbg(" %p .. %p: %s", obj->mapbase, obj->mapbase + obj->mapsize - 1, 3020 obj->path); 3021 if (obj->textrel) 3022 dbg(" WARNING: %s has impure text", obj->path); 3023 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 3024 obj->path); 3025 3026 return (obj); 3027 3028 errp: 3029 munmap(obj->mapbase, obj->mapsize); 3030 obj->path = NULL; /* obj->path is owned and freed by caller */ 3031 obj_free(obj); 3032 return (NULL); 3033 } 3034 3035 static int 3036 load_kpreload(const void *addr) 3037 { 3038 Obj_Entry *obj; 3039 const Elf_Ehdr *ehdr; 3040 const Elf_Phdr *phdr, *phlimit, *phdyn, *seg0, *segn; 3041 static const char kname[] = "[vdso]"; 3042 3043 ehdr = addr; 3044 if (!check_elf_headers(ehdr, "kpreload")) 3045 return (-1); 3046 obj = obj_new(); 3047 phdr = (const Elf_Phdr *)((const char *)addr + ehdr->e_phoff); 3048 obj->phdr = phdr; 3049 obj->phnum = ehdr->e_phnum; 3050 phlimit = phdr + ehdr->e_phnum; 3051 seg0 = segn = NULL; 3052 3053 for (; phdr < phlimit; phdr++) { 3054 switch (phdr->p_type) { 3055 case PT_DYNAMIC: 3056 phdyn = phdr; 3057 break; 3058 case PT_GNU_STACK: 3059 /* Absense of PT_GNU_STACK implies stack_flags == 0. */ 3060 obj->stack_flags = phdr->p_flags; 3061 break; 3062 case PT_LOAD: 3063 if (seg0 == NULL || seg0->p_vaddr > phdr->p_vaddr) 3064 seg0 = phdr; 3065 if (segn == NULL || 3066 segn->p_vaddr + segn->p_memsz < 3067 phdr->p_vaddr + phdr->p_memsz) 3068 segn = phdr; 3069 break; 3070 } 3071 } 3072 3073 obj->mapbase = __DECONST(caddr_t, addr); 3074 obj->mapsize = segn->p_vaddr + segn->p_memsz; 3075 obj->vaddrbase = 0; 3076 obj->relocbase = obj->mapbase; 3077 3078 object_add_name(obj, kname); 3079 obj->path = xstrdup(kname); 3080 obj->dynamic = (const Elf_Dyn *)(obj->relocbase + phdyn->p_vaddr); 3081 3082 if (!digest_dynamic(obj, 0)) { 3083 obj_free(obj); 3084 return (-1); 3085 } 3086 3087 /* 3088 * We assume that kernel-preloaded object does not need 3089 * relocation. It is currently written into read-only page, 3090 * handling relocations would mean we need to allocate at 3091 * least one additional page per AS. 3092 */ 3093 dbg("%s mapbase %p phdrs %p PT_LOAD phdr %p vaddr %p dynamic %p", 3094 obj->path, obj->mapbase, obj->phdr, seg0, 3095 obj->relocbase + seg0->p_vaddr, obj->dynamic); 3096 3097 TAILQ_INSERT_TAIL(&obj_list, obj, next); 3098 obj_count++; 3099 obj_loads++; 3100 linkmap_add(obj); /* for GDB & dlinfo() */ 3101 max_stack_flags |= obj->stack_flags; 3102 3103 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 3104 obj->path); 3105 return (0); 3106 } 3107 3108 Obj_Entry * 3109 obj_from_addr(const void *addr) 3110 { 3111 Obj_Entry *obj; 3112 3113 TAILQ_FOREACH(obj, &obj_list, next) { 3114 if (obj->marker) 3115 continue; 3116 if (addr < (void *)obj->mapbase) 3117 continue; 3118 if (addr < (void *)(obj->mapbase + obj->mapsize)) 3119 return obj; 3120 } 3121 return (NULL); 3122 } 3123 3124 static void 3125 preinit_main(RtldLockState *lockstate) 3126 { 3127 uintptr_t *preinit_addr; 3128 int index; 3129 3130 preinit_addr = obj_main->preinit_array; 3131 if (preinit_addr == NULL) 3132 return; 3133 3134 lock_release(rtld_bind_lock, lockstate); 3135 for (index = 0; index < obj_main->preinit_array_num; index++) { 3136 if (preinit_addr[index] != 0 && preinit_addr[index] != 1) { 3137 dbg("calling preinit function for %s at %p", 3138 obj_main->path, (void *)preinit_addr[index]); 3139 LD_UTRACE(UTRACE_INIT_CALL, obj_main, 3140 (void *)preinit_addr[index], 0, 0, obj_main->path); 3141 call_init_pointer(obj_main, preinit_addr[index]); 3142 } 3143 } 3144 wlock_acquire(rtld_bind_lock, lockstate); 3145 } 3146 3147 /* 3148 * Call the finalization functions for each of the objects in "list" 3149 * belonging to the DAG of "root" and referenced once. If NULL "root" 3150 * is specified, every finalization function will be called regardless 3151 * of the reference count and the list elements won't be freed. All of 3152 * the objects are expected to have non-NULL fini functions. 3153 */ 3154 static void 3155 objlist_call_fini(Objlist *list, Obj_Entry *root, RtldLockState *lockstate) 3156 { 3157 Objlist_Entry *elm; 3158 struct dlerror_save *saved_msg; 3159 uintptr_t *fini_addr; 3160 int index; 3161 3162 assert(root == NULL || root->refcount == 1); 3163 3164 if (root != NULL) 3165 root->doomed = true; 3166 3167 /* 3168 * Preserve the current error message since a fini function might 3169 * call into the dynamic linker and overwrite it. 3170 */ 3171 saved_msg = errmsg_save(); 3172 do { 3173 STAILQ_FOREACH(elm, list, link) { 3174 if (root != NULL && 3175 (elm->obj->refcount != 1 || 3176 objlist_find(&root->dagmembers, elm->obj) == 3177 NULL)) 3178 continue; 3179 /* Remove object from fini list to prevent recursive 3180 * invocation. */ 3181 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 3182 /* Ensure that new references cannot be acquired. */ 3183 elm->obj->doomed = true; 3184 3185 hold_object(elm->obj); 3186 lock_release(rtld_bind_lock, lockstate); 3187 /* 3188 * It is legal to have both DT_FINI and DT_FINI_ARRAY 3189 * defined. When this happens, DT_FINI_ARRAY is 3190 * processed first. 3191 */ 3192 fini_addr = elm->obj->fini_array; 3193 if (fini_addr != NULL && elm->obj->fini_array_num > 0) { 3194 for (index = elm->obj->fini_array_num - 1; 3195 index >= 0; index--) { 3196 if (fini_addr[index] != 0 && 3197 fini_addr[index] != 1 && 3198 fini_addr[index] != (Elf_Addr)-1) { 3199 dbg("calling fini function for %s at %p", 3200 elm->obj->path, 3201 (void *)fini_addr[index]); 3202 LD_UTRACE(UTRACE_FINI_CALL, 3203 elm->obj, 3204 (void *)fini_addr[index], 0, 3205 0, elm->obj->path); 3206 call_initfini_pointer(elm->obj, 3207 fini_addr[index]); 3208 } 3209 } 3210 } 3211 if (elm->obj->fini != 0) { 3212 dbg("calling fini function for %s at %p", 3213 elm->obj->path, (void *)elm->obj->fini); 3214 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, 3215 (void *)elm->obj->fini, 0, 0, 3216 elm->obj->path); 3217 call_initfini_pointer(elm->obj, elm->obj->fini); 3218 } 3219 wlock_acquire(rtld_bind_lock, lockstate); 3220 unhold_object(elm->obj); 3221 /* No need to free anything if process is going down. */ 3222 if (root != NULL) 3223 free(elm); 3224 /* 3225 * We must restart the list traversal after every fini 3226 * call because a dlclose() call from the fini function 3227 * or from another thread might have modified the 3228 * reference counts. 3229 */ 3230 break; 3231 } 3232 } while (elm != NULL); 3233 errmsg_restore(saved_msg); 3234 } 3235 3236 /* 3237 * Call the initialization functions for each of the objects in 3238 * "list". All of the objects are expected to have non-NULL init 3239 * functions. 3240 */ 3241 static void 3242 objlist_call_init(Objlist *list, RtldLockState *lockstate) 3243 { 3244 Objlist_Entry *elm; 3245 Obj_Entry *obj; 3246 struct dlerror_save *saved_msg; 3247 uintptr_t *init_addr; 3248 void (*reg)(void (*)(void)); 3249 int index; 3250 3251 /* 3252 * Clean init_scanned flag so that objects can be rechecked and 3253 * possibly initialized earlier if any of vectors called below 3254 * cause the change by using dlopen. 3255 */ 3256 TAILQ_FOREACH(obj, &obj_list, next) { 3257 if (obj->marker) 3258 continue; 3259 obj->init_scanned = false; 3260 } 3261 3262 /* 3263 * Preserve the current error message since an init function might 3264 * call into the dynamic linker and overwrite it. 3265 */ 3266 saved_msg = errmsg_save(); 3267 STAILQ_FOREACH(elm, list, link) { 3268 if (elm->obj->init_done) /* Initialized early. */ 3269 continue; 3270 /* 3271 * Race: other thread might try to use this object before 3272 * current one completes the initialization. Not much can be 3273 * done here without better locking. 3274 */ 3275 elm->obj->init_done = true; 3276 hold_object(elm->obj); 3277 reg = NULL; 3278 if (elm->obj == obj_main && obj_main->crt_no_init) { 3279 reg = (void (*)(void (*)(void))) 3280 get_program_var_addr("__libc_atexit", lockstate); 3281 } 3282 lock_release(rtld_bind_lock, lockstate); 3283 if (reg != NULL) { 3284 reg(rtld_exit); 3285 rtld_exit_ptr = rtld_nop_exit; 3286 } 3287 3288 /* 3289 * It is legal to have both DT_INIT and DT_INIT_ARRAY defined. 3290 * When this happens, DT_INIT is processed first. 3291 */ 3292 if (elm->obj->init != 0) { 3293 dbg("calling init function for %s at %p", 3294 elm->obj->path, (void *)elm->obj->init); 3295 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, 3296 (void *)elm->obj->init, 0, 0, elm->obj->path); 3297 call_init_pointer(elm->obj, elm->obj->init); 3298 } 3299 init_addr = elm->obj->init_array; 3300 if (init_addr != NULL) { 3301 for (index = 0; index < elm->obj->init_array_num; 3302 index++) { 3303 if (init_addr[index] != 0 && 3304 init_addr[index] != 1 && 3305 init_addr[index] != (Elf_Addr)-1) { 3306 dbg("calling init function for %s at %p", 3307 elm->obj->path, 3308 (void *)init_addr[index]); 3309 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, 3310 (void *)init_addr[index], 0, 0, 3311 elm->obj->path); 3312 call_init_pointer(elm->obj, 3313 init_addr[index]); 3314 } 3315 } 3316 } 3317 wlock_acquire(rtld_bind_lock, lockstate); 3318 unhold_object(elm->obj); 3319 } 3320 errmsg_restore(saved_msg); 3321 } 3322 3323 static void 3324 objlist_clear(Objlist *list) 3325 { 3326 Objlist_Entry *elm; 3327 3328 while (!STAILQ_EMPTY(list)) { 3329 elm = STAILQ_FIRST(list); 3330 STAILQ_REMOVE_HEAD(list, link); 3331 free(elm); 3332 } 3333 } 3334 3335 static Objlist_Entry * 3336 objlist_find(Objlist *list, const Obj_Entry *obj) 3337 { 3338 Objlist_Entry *elm; 3339 3340 STAILQ_FOREACH(elm, list, link) 3341 if (elm->obj == obj) 3342 return elm; 3343 return (NULL); 3344 } 3345 3346 static void 3347 objlist_init(Objlist *list) 3348 { 3349 STAILQ_INIT(list); 3350 } 3351 3352 static void 3353 objlist_push_head(Objlist *list, Obj_Entry *obj) 3354 { 3355 Objlist_Entry *elm; 3356 3357 elm = NEW(Objlist_Entry); 3358 elm->obj = obj; 3359 STAILQ_INSERT_HEAD(list, elm, link); 3360 } 3361 3362 static void 3363 objlist_push_tail(Objlist *list, Obj_Entry *obj) 3364 { 3365 Objlist_Entry *elm; 3366 3367 elm = NEW(Objlist_Entry); 3368 elm->obj = obj; 3369 STAILQ_INSERT_TAIL(list, elm, link); 3370 } 3371 3372 static void 3373 objlist_put_after(Objlist *list, Obj_Entry *listobj, Obj_Entry *obj) 3374 { 3375 Objlist_Entry *elm, *listelm; 3376 3377 STAILQ_FOREACH(listelm, list, link) { 3378 if (listelm->obj == listobj) 3379 break; 3380 } 3381 elm = NEW(Objlist_Entry); 3382 elm->obj = obj; 3383 if (listelm != NULL) 3384 STAILQ_INSERT_AFTER(list, listelm, elm, link); 3385 else 3386 STAILQ_INSERT_TAIL(list, elm, link); 3387 } 3388 3389 static void 3390 objlist_remove(Objlist *list, Obj_Entry *obj) 3391 { 3392 Objlist_Entry *elm; 3393 3394 if ((elm = objlist_find(list, obj)) != NULL) { 3395 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 3396 free(elm); 3397 } 3398 } 3399 3400 /* 3401 * Relocate dag rooted in the specified object. 3402 * Returns 0 on success, or -1 on failure. 3403 */ 3404 3405 static int 3406 relocate_object_dag(Obj_Entry *root, bool bind_now, Obj_Entry *rtldobj, 3407 int flags, RtldLockState *lockstate) 3408 { 3409 Objlist_Entry *elm; 3410 int error; 3411 3412 error = 0; 3413 STAILQ_FOREACH(elm, &root->dagmembers, link) { 3414 error = relocate_object(elm->obj, bind_now, rtldobj, flags, 3415 lockstate); 3416 if (error == -1) 3417 break; 3418 } 3419 return (error); 3420 } 3421 3422 /* 3423 * Prepare for, or clean after, relocating an object marked with 3424 * DT_TEXTREL or DF_TEXTREL. Before relocating, all read-only 3425 * segments are remapped read-write. After relocations are done, the 3426 * segment's permissions are returned back to the modes specified in 3427 * the phdrs. If any relocation happened, or always for wired 3428 * program, COW is triggered. 3429 */ 3430 static int 3431 reloc_textrel_prot(Obj_Entry *obj, bool before) 3432 { 3433 const Elf_Phdr *ph; 3434 void *base; 3435 size_t sz; 3436 int prot; 3437 3438 for (ph = obj->phdr; ph < obj->phdr + obj->phnum; ph++) { 3439 if (ph->p_type != PT_LOAD || (ph->p_flags & PF_W) != 0) 3440 continue; 3441 base = obj->relocbase + rtld_trunc_page(ph->p_vaddr); 3442 sz = rtld_round_page(ph->p_vaddr + ph->p_filesz) - 3443 rtld_trunc_page(ph->p_vaddr); 3444 prot = before ? (PROT_READ | PROT_WRITE) : 3445 convert_prot(ph->p_flags); 3446 if (mprotect(base, sz, prot) == -1) { 3447 _rtld_error("%s: Cannot write-%sable text segment: %s", 3448 obj->path, before ? "en" : "dis", 3449 rtld_strerror(errno)); 3450 return (-1); 3451 } 3452 } 3453 return (0); 3454 } 3455 3456 /* Process RELR relative relocations. */ 3457 static void 3458 reloc_relr(Obj_Entry *obj) 3459 { 3460 const Elf_Relr *relr, *relrlim; 3461 Elf_Addr *where; 3462 3463 relrlim = (const Elf_Relr *)((const char *)obj->relr + obj->relrsize); 3464 for (relr = obj->relr; relr < relrlim; relr++) { 3465 Elf_Relr entry = *relr; 3466 3467 if ((entry & 1) == 0) { 3468 where = (Elf_Addr *)(obj->relocbase + entry); 3469 *where++ += (Elf_Addr)obj->relocbase; 3470 } else { 3471 for (long i = 0; (entry >>= 1) != 0; i++) 3472 if ((entry & 1) != 0) 3473 where[i] += (Elf_Addr)obj->relocbase; 3474 where += CHAR_BIT * sizeof(Elf_Relr) - 1; 3475 } 3476 } 3477 } 3478 3479 /* 3480 * Relocate single object. 3481 * Returns 0 on success, or -1 on failure. 3482 */ 3483 static int 3484 relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, int flags, 3485 RtldLockState *lockstate) 3486 { 3487 if (obj->relocated) 3488 return (0); 3489 obj->relocated = true; 3490 if (obj != rtldobj) 3491 dbg("relocating \"%s\"", obj->path); 3492 3493 if (obj->symtab == NULL || obj->strtab == NULL || 3494 !(obj->valid_hash_sysv || obj->valid_hash_gnu)) 3495 dbg("object %s has no run-time symbol table", obj->path); 3496 3497 /* There are relocations to the write-protected text segment. */ 3498 if (obj->textrel && reloc_textrel_prot(obj, true) != 0) 3499 return (-1); 3500 3501 /* Process the non-PLT non-IFUNC relocations. */ 3502 if (reloc_non_plt(obj, rtldobj, flags, lockstate)) 3503 return (-1); 3504 reloc_relr(obj); 3505 3506 /* Re-protected the text segment. */ 3507 if (obj->textrel && reloc_textrel_prot(obj, false) != 0) 3508 return (-1); 3509 3510 /* Set the special PLT or GOT entries. */ 3511 init_pltgot(obj); 3512 3513 /* Process the PLT relocations. */ 3514 if (reloc_plt(obj, flags, lockstate) == -1) 3515 return (-1); 3516 /* Relocate the jump slots if we are doing immediate binding. */ 3517 if ((obj->bind_now || bind_now) && 3518 reloc_jmpslots(obj, flags, lockstate) == -1) 3519 return (-1); 3520 3521 if (obj != rtldobj && !obj->mainprog && obj_enforce_relro(obj) == -1) 3522 return (-1); 3523 3524 /* 3525 * Set up the magic number and version in the Obj_Entry. These 3526 * were checked in the crt1.o from the original ElfKit, so we 3527 * set them for backward compatibility. 3528 */ 3529 obj->magic = RTLD_MAGIC; 3530 obj->version = RTLD_VERSION; 3531 3532 return (0); 3533 } 3534 3535 /* 3536 * Relocate newly-loaded shared objects. The argument is a pointer to 3537 * the Obj_Entry for the first such object. All objects from the first 3538 * to the end of the list of objects are relocated. Returns 0 on success, 3539 * or -1 on failure. 3540 */ 3541 static int 3542 relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj, int flags, 3543 RtldLockState *lockstate) 3544 { 3545 Obj_Entry *obj; 3546 int error; 3547 3548 for (error = 0, obj = first; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 3549 if (obj->marker) 3550 continue; 3551 error = relocate_object(obj, bind_now, rtldobj, flags, 3552 lockstate); 3553 if (error == -1) 3554 break; 3555 } 3556 return (error); 3557 } 3558 3559 /* 3560 * The handling of R_MACHINE_IRELATIVE relocations and jumpslots 3561 * referencing STT_GNU_IFUNC symbols is postponed till the other 3562 * relocations are done. The indirect functions specified as 3563 * ifunc are allowed to call other symbols, so we need to have 3564 * objects relocated before asking for resolution from indirects. 3565 * 3566 * The R_MACHINE_IRELATIVE slots are resolved in greedy fashion, 3567 * instead of the usual lazy handling of PLT slots. It is 3568 * consistent with how GNU does it. 3569 */ 3570 static int 3571 resolve_object_ifunc(Obj_Entry *obj, bool bind_now, int flags, 3572 RtldLockState *lockstate) 3573 { 3574 if (obj->ifuncs_resolved) 3575 return (0); 3576 obj->ifuncs_resolved = true; 3577 if (!obj->irelative && !obj->irelative_nonplt && 3578 !((obj->bind_now || bind_now) && obj->gnu_ifunc) && 3579 !obj->non_plt_gnu_ifunc) 3580 return (0); 3581 if (obj_disable_relro(obj) == -1 || 3582 (obj->irelative && reloc_iresolve(obj, lockstate) == -1) || 3583 (obj->irelative_nonplt && 3584 reloc_iresolve_nonplt(obj, lockstate) == -1) || 3585 ((obj->bind_now || bind_now) && obj->gnu_ifunc && 3586 reloc_gnu_ifunc(obj, flags, lockstate) == -1) || 3587 (obj->non_plt_gnu_ifunc && 3588 reloc_non_plt(obj, &obj_rtld, flags | SYMLOOK_IFUNC, 3589 lockstate) == -1) || 3590 obj_enforce_relro(obj) == -1) 3591 return (-1); 3592 return (0); 3593 } 3594 3595 static int 3596 initlist_objects_ifunc(Objlist *list, bool bind_now, int flags, 3597 RtldLockState *lockstate) 3598 { 3599 Objlist_Entry *elm; 3600 Obj_Entry *obj; 3601 3602 STAILQ_FOREACH(elm, list, link) { 3603 obj = elm->obj; 3604 if (obj->marker) 3605 continue; 3606 if (resolve_object_ifunc(obj, bind_now, flags, lockstate) == -1) 3607 return (-1); 3608 } 3609 return (0); 3610 } 3611 3612 /* 3613 * Cleanup procedure. It will be called (by the atexit mechanism) just 3614 * before the process exits. 3615 */ 3616 static void 3617 rtld_exit(void) 3618 { 3619 RtldLockState lockstate; 3620 3621 wlock_acquire(rtld_bind_lock, &lockstate); 3622 dbg("rtld_exit()"); 3623 objlist_call_fini(&list_fini, NULL, &lockstate); 3624 /* No need to remove the items from the list, since we are exiting. */ 3625 if (!libmap_disable) 3626 lm_fini(); 3627 lock_release(rtld_bind_lock, &lockstate); 3628 } 3629 3630 static void 3631 rtld_nop_exit(void) 3632 { 3633 } 3634 3635 /* 3636 * Parse string of the format '#number/name", where number must be a 3637 * decimal number of the opened file descriptor listed in 3638 * LD_LIBRARY_PATH_FDS. If successful, tries to open dso name under 3639 * dirfd number and returns resulting fd. 3640 * On any error, returns -1. 3641 */ 3642 static int 3643 try_fds_open(const char *name, const char *path) 3644 { 3645 const char *n; 3646 char *envcopy, *fdstr, *last_token, *ncopy; 3647 size_t len; 3648 int fd, dirfd, dirfd_path; 3649 3650 if (!trust || name[0] != '#' || path == NULL) 3651 return (-1); 3652 3653 name++; 3654 n = strchr(name, '/'); 3655 if (n == NULL) 3656 return (-1); 3657 len = n - name; 3658 ncopy = xmalloc(len + 1); 3659 memcpy(ncopy, name, len); 3660 ncopy[len] = '\0'; 3661 dirfd = parse_integer(ncopy); 3662 free(ncopy); 3663 if (dirfd == -1) 3664 return (-1); 3665 3666 envcopy = xstrdup(path); 3667 dirfd_path = -1; 3668 for (fdstr = strtok_r(envcopy, ":", &last_token); fdstr != NULL; 3669 fdstr = strtok_r(NULL, ":", &last_token)) { 3670 dirfd_path = parse_integer(fdstr); 3671 if (dirfd_path == dirfd) 3672 break; 3673 } 3674 free(envcopy); 3675 if (dirfd_path != dirfd) 3676 return (-1); 3677 3678 fd = __sys_openat(dirfd, n + 1, O_RDONLY | O_CLOEXEC | O_VERIFY); 3679 return (fd); 3680 } 3681 3682 /* 3683 * Iterate over a search path, translate each element, and invoke the 3684 * callback on the result. 3685 */ 3686 static void * 3687 path_enumerate(const char *path, path_enum_proc callback, 3688 const char *refobj_path, void *arg) 3689 { 3690 const char *trans; 3691 if (path == NULL) 3692 return (NULL); 3693 3694 path += strspn(path, ":;"); 3695 while (*path != '\0') { 3696 size_t len; 3697 char *res; 3698 3699 len = strcspn(path, ":;"); 3700 trans = lm_findn(refobj_path, path, len); 3701 if (trans) 3702 res = callback(trans, strlen(trans), arg); 3703 else 3704 res = callback(path, len, arg); 3705 3706 if (res != NULL) 3707 return (res); 3708 3709 path += len; 3710 path += strspn(path, ":;"); 3711 } 3712 3713 return (NULL); 3714 } 3715 3716 struct try_library_args { 3717 const char *name; 3718 size_t namelen; 3719 char *buffer; 3720 size_t buflen; 3721 int fd; 3722 }; 3723 3724 static void * 3725 try_library_path(const char *dir, size_t dirlen, void *param) 3726 { 3727 struct try_library_args *arg; 3728 int fd; 3729 3730 arg = param; 3731 if (*dir == '/' || trust) { 3732 char *pathname; 3733 3734 if (dirlen + 1 + arg->namelen + 1 > arg->buflen) 3735 return (NULL); 3736 3737 pathname = arg->buffer; 3738 strncpy(pathname, dir, dirlen); 3739 pathname[dirlen] = '/'; 3740 strcpy(pathname + dirlen + 1, arg->name); 3741 3742 dbg(" Trying \"%s\"", pathname); 3743 fd = open(pathname, O_RDONLY | O_CLOEXEC | O_VERIFY); 3744 if (fd >= 0) { 3745 dbg(" Opened \"%s\", fd %d", pathname, fd); 3746 pathname = xmalloc(dirlen + 1 + arg->namelen + 1); 3747 strcpy(pathname, arg->buffer); 3748 arg->fd = fd; 3749 return (pathname); 3750 } else { 3751 dbg(" Failed to open \"%s\": %s", pathname, 3752 rtld_strerror(errno)); 3753 } 3754 } 3755 return (NULL); 3756 } 3757 3758 static char * 3759 search_library_path(const char *name, const char *path, const char *refobj_path, 3760 int *fdp) 3761 { 3762 char *p; 3763 struct try_library_args arg; 3764 3765 if (path == NULL) 3766 return (NULL); 3767 3768 arg.name = name; 3769 arg.namelen = strlen(name); 3770 arg.buffer = xmalloc(PATH_MAX); 3771 arg.buflen = PATH_MAX; 3772 arg.fd = -1; 3773 3774 p = path_enumerate(path, try_library_path, refobj_path, &arg); 3775 *fdp = arg.fd; 3776 3777 free(arg.buffer); 3778 3779 return (p); 3780 } 3781 3782 /* 3783 * Finds the library with the given name using the directory descriptors 3784 * listed in the LD_LIBRARY_PATH_FDS environment variable. 3785 * 3786 * Returns a freshly-opened close-on-exec file descriptor for the library, 3787 * or -1 if the library cannot be found. 3788 */ 3789 static char * 3790 search_library_pathfds(const char *name, const char *path, int *fdp) 3791 { 3792 char *envcopy, *fdstr, *found, *last_token; 3793 size_t len; 3794 int dirfd, fd; 3795 3796 dbg("%s('%s', '%s', fdp)", __func__, name, path); 3797 3798 /* Don't load from user-specified libdirs into setuid binaries. */ 3799 if (!trust) 3800 return (NULL); 3801 3802 /* We can't do anything if LD_LIBRARY_PATH_FDS isn't set. */ 3803 if (path == NULL) 3804 return (NULL); 3805 3806 /* LD_LIBRARY_PATH_FDS only works with relative paths. */ 3807 if (name[0] == '/') { 3808 dbg("Absolute path (%s) passed to %s", name, __func__); 3809 return (NULL); 3810 } 3811 3812 /* 3813 * Use strtok_r() to walk the FD:FD:FD list. This requires a local 3814 * copy of the path, as strtok_r rewrites separator tokens 3815 * with '\0'. 3816 */ 3817 found = NULL; 3818 envcopy = xstrdup(path); 3819 for (fdstr = strtok_r(envcopy, ":", &last_token); fdstr != NULL; 3820 fdstr = strtok_r(NULL, ":", &last_token)) { 3821 dirfd = parse_integer(fdstr); 3822 if (dirfd < 0) { 3823 _rtld_error("failed to parse directory FD: '%s'", 3824 fdstr); 3825 break; 3826 } 3827 fd = __sys_openat(dirfd, name, O_RDONLY | O_CLOEXEC | O_VERIFY); 3828 if (fd >= 0) { 3829 *fdp = fd; 3830 len = strlen(fdstr) + strlen(name) + 3; 3831 found = xmalloc(len); 3832 if (rtld_snprintf(found, len, "#%d/%s", dirfd, name) < 3833 0) { 3834 _rtld_error("error generating '%d/%s'", dirfd, 3835 name); 3836 rtld_die(); 3837 } 3838 dbg("open('%s') => %d", found, fd); 3839 break; 3840 } 3841 } 3842 free(envcopy); 3843 3844 return (found); 3845 } 3846 3847 int 3848 dlclose(void *handle) 3849 { 3850 RtldLockState lockstate; 3851 int error; 3852 3853 wlock_acquire(rtld_bind_lock, &lockstate); 3854 error = dlclose_locked(handle, &lockstate); 3855 lock_release(rtld_bind_lock, &lockstate); 3856 return (error); 3857 } 3858 3859 static int 3860 dlclose_locked(void *handle, RtldLockState *lockstate) 3861 { 3862 Obj_Entry *root; 3863 3864 root = dlcheck(handle); 3865 if (root == NULL) 3866 return (-1); 3867 LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount, 3868 root->path); 3869 3870 /* Unreference the object and its dependencies. */ 3871 root->dl_refcount--; 3872 3873 if (root->refcount == 1) { 3874 /* 3875 * The object will be no longer referenced, so we must unload 3876 * it. First, call the fini functions. 3877 */ 3878 objlist_call_fini(&list_fini, root, lockstate); 3879 3880 unref_dag(root); 3881 3882 /* Finish cleaning up the newly-unreferenced objects. */ 3883 GDB_STATE(RT_DELETE, &root->linkmap); 3884 unload_object(root, lockstate); 3885 GDB_STATE(RT_CONSISTENT, NULL); 3886 } else 3887 unref_dag(root); 3888 3889 LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL); 3890 return (0); 3891 } 3892 3893 char * 3894 dlerror(void) 3895 { 3896 if (*(lockinfo.dlerror_seen()) != 0) 3897 return (NULL); 3898 *lockinfo.dlerror_seen() = 1; 3899 return (lockinfo.dlerror_loc()); 3900 } 3901 3902 /* 3903 * This function is deprecated and has no effect. 3904 */ 3905 void 3906 dllockinit(void *context, void *(*_lock_create)(void *context)__unused, 3907 void (*_rlock_acquire)(void *lock) __unused, 3908 void (*_wlock_acquire)(void *lock) __unused, 3909 void (*_lock_release)(void *lock) __unused, 3910 void (*_lock_destroy)(void *lock) __unused, 3911 void (*context_destroy)(void *context)) 3912 { 3913 static void *cur_context; 3914 static void (*cur_context_destroy)(void *); 3915 3916 /* Just destroy the context from the previous call, if necessary. */ 3917 if (cur_context_destroy != NULL) 3918 cur_context_destroy(cur_context); 3919 cur_context = context; 3920 cur_context_destroy = context_destroy; 3921 } 3922 3923 void * 3924 dlopen(const char *name, int mode) 3925 { 3926 return (rtld_dlopen(name, -1, mode)); 3927 } 3928 3929 void * 3930 fdlopen(int fd, int mode) 3931 { 3932 return (rtld_dlopen(NULL, fd, mode)); 3933 } 3934 3935 static void * 3936 rtld_dlopen(const char *name, int fd, int mode) 3937 { 3938 RtldLockState lockstate; 3939 int lo_flags; 3940 3941 LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name); 3942 ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1"; 3943 if (ld_tracing != NULL) { 3944 rlock_acquire(rtld_bind_lock, &lockstate); 3945 if (sigsetjmp(lockstate.env, 0) != 0) 3946 lock_upgrade(rtld_bind_lock, &lockstate); 3947 environ = __DECONST(char **, 3948 *get_program_var_addr("environ", &lockstate)); 3949 lock_release(rtld_bind_lock, &lockstate); 3950 } 3951 lo_flags = RTLD_LO_DLOPEN; 3952 if (mode & RTLD_NODELETE) 3953 lo_flags |= RTLD_LO_NODELETE; 3954 if (mode & RTLD_NOLOAD) 3955 lo_flags |= RTLD_LO_NOLOAD; 3956 if (mode & RTLD_DEEPBIND) 3957 lo_flags |= RTLD_LO_DEEPBIND; 3958 if (ld_tracing != NULL) 3959 lo_flags |= RTLD_LO_TRACE | RTLD_LO_IGNSTLS; 3960 3961 return (dlopen_object(name, fd, obj_main, lo_flags, 3962 mode & (RTLD_MODEMASK | RTLD_GLOBAL), NULL)); 3963 } 3964 3965 static void 3966 dlopen_cleanup(Obj_Entry *obj, RtldLockState *lockstate) 3967 { 3968 obj->dl_refcount--; 3969 unref_dag(obj); 3970 if (obj->refcount == 0) 3971 unload_object(obj, lockstate); 3972 } 3973 3974 static Obj_Entry * 3975 dlopen_object(const char *name, int fd, Obj_Entry *refobj, int lo_flags, 3976 int mode, RtldLockState *lockstate) 3977 { 3978 Obj_Entry *obj; 3979 Objlist initlist; 3980 RtldLockState mlockstate; 3981 int result; 3982 3983 dbg( 3984 "dlopen_object name \"%s\" fd %d refobj \"%s\" lo_flags %#x mode %#x", 3985 name != NULL ? name : "<null>", fd, 3986 refobj == NULL ? "<null>" : refobj->path, lo_flags, mode); 3987 objlist_init(&initlist); 3988 3989 if (lockstate == NULL && !(lo_flags & RTLD_LO_EARLY)) { 3990 wlock_acquire(rtld_bind_lock, &mlockstate); 3991 lockstate = &mlockstate; 3992 } 3993 GDB_STATE(RT_ADD, NULL); 3994 3995 obj = NULL; 3996 if (name == NULL && fd == -1) { 3997 obj = obj_main; 3998 obj->refcount++; 3999 } else { 4000 obj = load_object(name, fd, refobj, lo_flags); 4001 } 4002 4003 if (obj != NULL) { 4004 obj->dl_refcount++; 4005 if ((mode & RTLD_GLOBAL) != 0 && 4006 objlist_find(&list_global, obj) == NULL) 4007 objlist_push_tail(&list_global, obj); 4008 4009 if (!obj->init_done) { 4010 /* We loaded something new and have to init something. 4011 */ 4012 if ((lo_flags & RTLD_LO_DEEPBIND) != 0) 4013 obj->deepbind = true; 4014 result = 0; 4015 if ((lo_flags & (RTLD_LO_EARLY | 4016 RTLD_LO_IGNSTLS)) == 0 && 4017 obj->static_tls && !allocate_tls_offset(obj)) { 4018 _rtld_error( 4019 "%s: No space available for static Thread Local Storage", 4020 obj->path); 4021 result = -1; 4022 } 4023 if (result != -1) 4024 result = load_needed_objects(obj, 4025 lo_flags & (RTLD_LO_DLOPEN | RTLD_LO_EARLY | 4026 RTLD_LO_IGNSTLS | RTLD_LO_TRACE)); 4027 init_dag(obj); 4028 ref_dag(obj); 4029 if (result != -1) 4030 result = rtld_verify_versions(&obj->dagmembers); 4031 if (result != -1 && ld_tracing) 4032 goto trace; 4033 if (result == -1 || relocate_object_dag(obj, 4034 (mode & RTLD_MODEMASK) == RTLD_NOW, &obj_rtld, 4035 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 4036 lockstate) == -1) { 4037 dlopen_cleanup(obj, lockstate); 4038 obj = NULL; 4039 } else if ((lo_flags & RTLD_LO_EARLY) != 0) { 4040 /* 4041 * Do not call the init functions for early 4042 * loaded filtees. The image is still not 4043 * initialized enough for them to work. 4044 * 4045 * Our object is found by the global object list 4046 * and will be ordered among all init calls done 4047 * right before transferring control to main. 4048 */ 4049 } else { 4050 /* Make list of init functions to call. */ 4051 initlist_for_loaded_obj(obj, obj, &initlist); 4052 } 4053 /* 4054 * Process all no_delete or global objects here, given 4055 * them own DAGs to prevent their dependencies from 4056 * being unloaded. This has to be done after we have 4057 * loaded all of the dependencies, so that we do not 4058 * miss any. 4059 */ 4060 if (obj != NULL) 4061 process_z(obj); 4062 } else { 4063 /* 4064 * Bump the reference counts for objects on this DAG. If 4065 * this is the first dlopen() call for the object that 4066 * was already loaded as a dependency, initialize the 4067 * dag starting at it. 4068 */ 4069 init_dag(obj); 4070 ref_dag(obj); 4071 4072 if ((lo_flags & RTLD_LO_TRACE) != 0) 4073 goto trace; 4074 } 4075 if (obj != NULL && 4076 ((lo_flags & RTLD_LO_NODELETE) != 0 || obj->z_nodelete) && 4077 !obj->ref_nodel) { 4078 dbg("obj %s nodelete", obj->path); 4079 ref_dag(obj); 4080 obj->z_nodelete = obj->ref_nodel = true; 4081 } 4082 } 4083 4084 LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0, 4085 name); 4086 GDB_STATE(RT_CONSISTENT, obj ? &obj->linkmap : NULL); 4087 4088 if ((lo_flags & RTLD_LO_EARLY) == 0) { 4089 map_stacks_exec(lockstate); 4090 if (obj != NULL) 4091 distribute_static_tls(&initlist); 4092 } 4093 4094 if (initlist_objects_ifunc(&initlist, (mode & RTLD_MODEMASK) == 4095 RTLD_NOW, (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 4096 lockstate) == -1) { 4097 objlist_clear(&initlist); 4098 dlopen_cleanup(obj, lockstate); 4099 if (lockstate == &mlockstate) 4100 lock_release(rtld_bind_lock, lockstate); 4101 return (NULL); 4102 } 4103 4104 if ((lo_flags & RTLD_LO_EARLY) == 0) { 4105 /* Call the init functions. */ 4106 objlist_call_init(&initlist, lockstate); 4107 } 4108 objlist_clear(&initlist); 4109 if (lockstate == &mlockstate) 4110 lock_release(rtld_bind_lock, lockstate); 4111 return (obj); 4112 trace: 4113 trace_loaded_objects(obj, false); 4114 if (lockstate == &mlockstate) 4115 lock_release(rtld_bind_lock, lockstate); 4116 exit(0); 4117 } 4118 4119 static void * 4120 do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve, 4121 int flags) 4122 { 4123 DoneList donelist; 4124 const Obj_Entry *obj, *defobj; 4125 const Elf_Sym *def; 4126 SymLook req; 4127 RtldLockState lockstate; 4128 tls_index ti; 4129 void *sym; 4130 int res; 4131 4132 def = NULL; 4133 defobj = NULL; 4134 symlook_init(&req, name); 4135 req.ventry = ve; 4136 req.flags = flags | SYMLOOK_IN_PLT; 4137 req.lockstate = &lockstate; 4138 4139 LD_UTRACE(UTRACE_DLSYM_START, handle, NULL, 0, 0, name); 4140 rlock_acquire(rtld_bind_lock, &lockstate); 4141 if (sigsetjmp(lockstate.env, 0) != 0) { 4142 lock_upgrade(rtld_bind_lock, &lockstate); 4143 free(req.donelist_mem); 4144 req.donelist_mem = NULL; 4145 } 4146 if (handle == NULL || handle == RTLD_NEXT || handle == RTLD_DEFAULT || 4147 handle == RTLD_SELF) { 4148 if ((obj = obj_from_addr(retaddr)) == NULL) { 4149 _rtld_error("Cannot determine caller's shared object"); 4150 lock_release(rtld_bind_lock, &lockstate); 4151 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 4152 return (NULL); 4153 } 4154 if (handle == NULL) { /* Just the caller's shared object. */ 4155 res = symlook_obj(&req, obj); 4156 if (res == 0) { 4157 def = req.sym_out; 4158 defobj = req.defobj_out; 4159 } 4160 } else if (handle == RTLD_NEXT || /* Objects after caller's */ 4161 handle == RTLD_SELF) { /* ... caller included */ 4162 if (handle == RTLD_NEXT) 4163 obj = globallist_next(obj); 4164 for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 4165 if (obj->marker) 4166 continue; 4167 res = symlook_obj(&req, obj); 4168 if (res == 0) { 4169 if (def == NULL || 4170 (ld_dynamic_weak && 4171 ELF_ST_BIND( 4172 req.sym_out->st_info) != 4173 STB_WEAK)) { 4174 def = req.sym_out; 4175 defobj = req.defobj_out; 4176 if (!ld_dynamic_weak || 4177 ELF_ST_BIND(def->st_info) != 4178 STB_WEAK) 4179 break; 4180 } 4181 } 4182 } 4183 /* 4184 * Search the dynamic linker itself, and possibly 4185 * resolve the symbol from there. This is how the 4186 * application links to dynamic linker services such as 4187 * dlopen. Note that we ignore ld_dynamic_weak == false 4188 * case, always overriding weak symbols by rtld 4189 * definitions. 4190 */ 4191 if (def == NULL || 4192 ELF_ST_BIND(def->st_info) == STB_WEAK) { 4193 res = symlook_obj(&req, &obj_rtld); 4194 if (res == 0) { 4195 def = req.sym_out; 4196 defobj = req.defobj_out; 4197 } 4198 } 4199 } else { 4200 assert(handle == RTLD_DEFAULT); 4201 res = symlook_default(&req, obj); 4202 if (res == 0) { 4203 defobj = req.defobj_out; 4204 def = req.sym_out; 4205 } 4206 } 4207 } else { 4208 if ((obj = dlcheck(handle)) == NULL) { 4209 lock_release(rtld_bind_lock, &lockstate); 4210 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 4211 return (NULL); 4212 } 4213 4214 donelist_init(&donelist, &req); 4215 if (obj->mainprog) { 4216 /* Handle obtained by dlopen(NULL, ...) implies global 4217 * scope. */ 4218 res = symlook_global(&req, &donelist); 4219 if (res == 0) { 4220 def = req.sym_out; 4221 defobj = req.defobj_out; 4222 } 4223 /* 4224 * Search the dynamic linker itself, and possibly 4225 * resolve the symbol from there. This is how the 4226 * application links to dynamic linker services such as 4227 * dlopen. 4228 */ 4229 if (def == NULL || 4230 ELF_ST_BIND(def->st_info) == STB_WEAK) { 4231 res = symlook_obj(&req, &obj_rtld); 4232 if (res == 0) { 4233 def = req.sym_out; 4234 defobj = req.defobj_out; 4235 } 4236 } 4237 } else { 4238 /* Search the whole DAG rooted at the given object. */ 4239 res = symlook_list(&req, &obj->dagmembers, &donelist); 4240 if (res == 0) { 4241 def = req.sym_out; 4242 defobj = req.defobj_out; 4243 } 4244 } 4245 donelist_free(&donelist); 4246 } 4247 4248 if (def != NULL) { 4249 lock_release(rtld_bind_lock, &lockstate); 4250 4251 /* 4252 * The value required by the caller is derived from the value 4253 * of the symbol. this is simply the relocated value of the 4254 * symbol. 4255 */ 4256 if (ELF_ST_TYPE(def->st_info) == STT_FUNC) 4257 sym = make_function_pointer(def, defobj); 4258 else if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 4259 sym = rtld_resolve_ifunc(defobj, def); 4260 else if (ELF_ST_TYPE(def->st_info) == STT_TLS) { 4261 ti.ti_module = defobj->tlsindex; 4262 ti.ti_offset = def->st_value - TLS_DTV_OFFSET; 4263 sym = __tls_get_addr(&ti); 4264 } else 4265 sym = defobj->relocbase + def->st_value; 4266 LD_UTRACE(UTRACE_DLSYM_STOP, handle, sym, 0, 0, name); 4267 return (sym); 4268 } 4269 4270 _rtld_error("Undefined symbol \"%s%s%s\"", name, ve != NULL ? "@" : "", 4271 ve != NULL ? ve->name : ""); 4272 lock_release(rtld_bind_lock, &lockstate); 4273 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 4274 return (NULL); 4275 } 4276 4277 void * 4278 dlsym(void *handle, const char *name) 4279 { 4280 return (do_dlsym(handle, name, __builtin_return_address(0), NULL, 4281 SYMLOOK_DLSYM)); 4282 } 4283 4284 dlfunc_t 4285 dlfunc(void *handle, const char *name) 4286 { 4287 union { 4288 void *d; 4289 dlfunc_t f; 4290 } rv; 4291 4292 rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL, 4293 SYMLOOK_DLSYM); 4294 return (rv.f); 4295 } 4296 4297 void * 4298 dlvsym(void *handle, const char *name, const char *version) 4299 { 4300 Ver_Entry ventry; 4301 4302 ventry.name = version; 4303 ventry.file = NULL; 4304 ventry.hash = elf_hash(version); 4305 ventry.flags = 0; 4306 return (do_dlsym(handle, name, __builtin_return_address(0), &ventry, 4307 SYMLOOK_DLSYM)); 4308 } 4309 4310 int 4311 _rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info) 4312 { 4313 const Obj_Entry *obj; 4314 RtldLockState lockstate; 4315 4316 rlock_acquire(rtld_bind_lock, &lockstate); 4317 obj = obj_from_addr(addr); 4318 if (obj == NULL) { 4319 _rtld_error("No shared object contains address"); 4320 lock_release(rtld_bind_lock, &lockstate); 4321 return (0); 4322 } 4323 rtld_fill_dl_phdr_info(obj, phdr_info); 4324 lock_release(rtld_bind_lock, &lockstate); 4325 return (1); 4326 } 4327 4328 int 4329 dladdr(const void *addr, Dl_info *info) 4330 { 4331 const Obj_Entry *obj; 4332 const Elf_Sym *def; 4333 void *symbol_addr; 4334 unsigned long symoffset; 4335 RtldLockState lockstate; 4336 4337 rlock_acquire(rtld_bind_lock, &lockstate); 4338 obj = obj_from_addr(addr); 4339 if (obj == NULL) { 4340 _rtld_error("No shared object contains address"); 4341 lock_release(rtld_bind_lock, &lockstate); 4342 return (0); 4343 } 4344 info->dli_fname = obj->path; 4345 info->dli_fbase = obj->mapbase; 4346 info->dli_saddr = (void *)0; 4347 info->dli_sname = NULL; 4348 4349 /* 4350 * Walk the symbol list looking for the symbol whose address is 4351 * closest to the address sent in. 4352 */ 4353 for (symoffset = 0; symoffset < obj->dynsymcount; symoffset++) { 4354 def = obj->symtab + symoffset; 4355 4356 /* 4357 * For skip the symbol if st_shndx is either SHN_UNDEF or 4358 * SHN_COMMON. 4359 */ 4360 if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON) 4361 continue; 4362 4363 /* 4364 * If the symbol is greater than the specified address, or if it 4365 * is further away from addr than the current nearest symbol, 4366 * then reject it. 4367 */ 4368 symbol_addr = obj->relocbase + def->st_value; 4369 if (symbol_addr > addr || symbol_addr < info->dli_saddr) 4370 continue; 4371 4372 /* Update our idea of the nearest symbol. */ 4373 info->dli_sname = obj->strtab + def->st_name; 4374 info->dli_saddr = symbol_addr; 4375 4376 /* Exact match? */ 4377 if (info->dli_saddr == addr) 4378 break; 4379 } 4380 lock_release(rtld_bind_lock, &lockstate); 4381 return (1); 4382 } 4383 4384 int 4385 dlinfo(void *handle, int request, void *p) 4386 { 4387 const Obj_Entry *obj; 4388 RtldLockState lockstate; 4389 int error; 4390 4391 rlock_acquire(rtld_bind_lock, &lockstate); 4392 4393 if (handle == NULL || handle == RTLD_SELF) { 4394 void *retaddr; 4395 4396 retaddr = __builtin_return_address(0); /* __GNUC__ only */ 4397 if ((obj = obj_from_addr(retaddr)) == NULL) 4398 _rtld_error("Cannot determine caller's shared object"); 4399 } else 4400 obj = dlcheck(handle); 4401 4402 if (obj == NULL) { 4403 lock_release(rtld_bind_lock, &lockstate); 4404 return (-1); 4405 } 4406 4407 error = 0; 4408 switch (request) { 4409 case RTLD_DI_LINKMAP: 4410 *((struct link_map const **)p) = &obj->linkmap; 4411 break; 4412 case RTLD_DI_ORIGIN: 4413 error = rtld_dirname(obj->path, p); 4414 break; 4415 4416 case RTLD_DI_SERINFOSIZE: 4417 case RTLD_DI_SERINFO: 4418 error = do_search_info(obj, request, (struct dl_serinfo *)p); 4419 break; 4420 4421 default: 4422 _rtld_error("Invalid request %d passed to dlinfo()", request); 4423 error = -1; 4424 } 4425 4426 lock_release(rtld_bind_lock, &lockstate); 4427 4428 return (error); 4429 } 4430 4431 static void 4432 rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info) 4433 { 4434 phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase; 4435 phdr_info->dlpi_name = obj->path; 4436 phdr_info->dlpi_phdr = obj->phdr; 4437 phdr_info->dlpi_phnum = obj->phnum; 4438 phdr_info->dlpi_tls_modid = obj->tlsindex; 4439 phdr_info->dlpi_tls_data = (char *)tls_get_addr_slow(_tcb_get(), 4440 obj->tlsindex, 0, true); 4441 phdr_info->dlpi_adds = obj_loads; 4442 phdr_info->dlpi_subs = obj_loads - obj_count; 4443 } 4444 4445 /* 4446 * It's completely UB to actually use this, so extreme caution is advised. It's 4447 * probably not what you want. 4448 */ 4449 int 4450 _dl_iterate_phdr_locked(__dl_iterate_hdr_callback callback, void *param) 4451 { 4452 struct dl_phdr_info phdr_info; 4453 Obj_Entry *obj; 4454 int error; 4455 4456 for (obj = globallist_curr(TAILQ_FIRST(&obj_list)); obj != NULL; 4457 obj = globallist_next(obj)) { 4458 rtld_fill_dl_phdr_info(obj, &phdr_info); 4459 error = callback(&phdr_info, sizeof(phdr_info), param); 4460 if (error != 0) 4461 return (error); 4462 } 4463 4464 rtld_fill_dl_phdr_info(&obj_rtld, &phdr_info); 4465 return (callback(&phdr_info, sizeof(phdr_info), param)); 4466 } 4467 4468 int 4469 dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param) 4470 { 4471 struct dl_phdr_info phdr_info; 4472 Obj_Entry *obj, marker; 4473 RtldLockState bind_lockstate, phdr_lockstate; 4474 int error; 4475 4476 init_marker(&marker); 4477 error = 0; 4478 4479 wlock_acquire(rtld_phdr_lock, &phdr_lockstate); 4480 wlock_acquire(rtld_bind_lock, &bind_lockstate); 4481 for (obj = globallist_curr(TAILQ_FIRST(&obj_list)); obj != NULL;) { 4482 TAILQ_INSERT_AFTER(&obj_list, obj, &marker, next); 4483 rtld_fill_dl_phdr_info(obj, &phdr_info); 4484 hold_object(obj); 4485 lock_release(rtld_bind_lock, &bind_lockstate); 4486 4487 error = callback(&phdr_info, sizeof phdr_info, param); 4488 4489 wlock_acquire(rtld_bind_lock, &bind_lockstate); 4490 unhold_object(obj); 4491 obj = globallist_next(&marker); 4492 TAILQ_REMOVE(&obj_list, &marker, next); 4493 if (error != 0) { 4494 lock_release(rtld_bind_lock, &bind_lockstate); 4495 lock_release(rtld_phdr_lock, &phdr_lockstate); 4496 return (error); 4497 } 4498 } 4499 4500 if (error == 0) { 4501 rtld_fill_dl_phdr_info(&obj_rtld, &phdr_info); 4502 lock_release(rtld_bind_lock, &bind_lockstate); 4503 error = callback(&phdr_info, sizeof(phdr_info), param); 4504 } 4505 lock_release(rtld_phdr_lock, &phdr_lockstate); 4506 return (error); 4507 } 4508 4509 static void * 4510 fill_search_info(const char *dir, size_t dirlen, void *param) 4511 { 4512 struct fill_search_info_args *arg; 4513 4514 arg = param; 4515 4516 if (arg->request == RTLD_DI_SERINFOSIZE) { 4517 arg->serinfo->dls_cnt++; 4518 arg->serinfo->dls_size += sizeof(struct dl_serpath) + dirlen + 4519 1; 4520 } else { 4521 struct dl_serpath *s_entry; 4522 4523 s_entry = arg->serpath; 4524 s_entry->dls_name = arg->strspace; 4525 s_entry->dls_flags = arg->flags; 4526 4527 strncpy(arg->strspace, dir, dirlen); 4528 arg->strspace[dirlen] = '\0'; 4529 4530 arg->strspace += dirlen + 1; 4531 arg->serpath++; 4532 } 4533 4534 return (NULL); 4535 } 4536 4537 static int 4538 do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info) 4539 { 4540 struct dl_serinfo _info; 4541 struct fill_search_info_args args; 4542 4543 args.request = RTLD_DI_SERINFOSIZE; 4544 args.serinfo = &_info; 4545 4546 _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 4547 _info.dls_cnt = 0; 4548 4549 path_enumerate(obj->rpath, fill_search_info, NULL, &args); 4550 path_enumerate(ld_library_path, fill_search_info, NULL, &args); 4551 path_enumerate(obj->runpath, fill_search_info, NULL, &args); 4552 path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, 4553 &args); 4554 if (!obj->z_nodeflib) 4555 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 4556 &args); 4557 4558 if (request == RTLD_DI_SERINFOSIZE) { 4559 info->dls_size = _info.dls_size; 4560 info->dls_cnt = _info.dls_cnt; 4561 return (0); 4562 } 4563 4564 if (info->dls_cnt != _info.dls_cnt || 4565 info->dls_size != _info.dls_size) { 4566 _rtld_error( 4567 "Uninitialized Dl_serinfo struct passed to dlinfo()"); 4568 return (-1); 4569 } 4570 4571 args.request = RTLD_DI_SERINFO; 4572 args.serinfo = info; 4573 args.serpath = &info->dls_serpath[0]; 4574 args.strspace = (char *)&info->dls_serpath[_info.dls_cnt]; 4575 4576 args.flags = LA_SER_RUNPATH; 4577 if (path_enumerate(obj->rpath, fill_search_info, NULL, &args) != NULL) 4578 return (-1); 4579 4580 args.flags = LA_SER_LIBPATH; 4581 if (path_enumerate(ld_library_path, fill_search_info, NULL, &args) != 4582 NULL) 4583 return (-1); 4584 4585 args.flags = LA_SER_RUNPATH; 4586 if (path_enumerate(obj->runpath, fill_search_info, NULL, &args) != NULL) 4587 return (-1); 4588 4589 args.flags = LA_SER_CONFIG; 4590 if (path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, 4591 &args) != NULL) 4592 return (-1); 4593 4594 args.flags = LA_SER_DEFAULT; 4595 if (!obj->z_nodeflib && 4596 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 4597 &args) != NULL) 4598 return (-1); 4599 return (0); 4600 } 4601 4602 static int 4603 rtld_dirname(const char *path, char *bname) 4604 { 4605 const char *endp; 4606 4607 /* Empty or NULL string gets treated as "." */ 4608 if (path == NULL || *path == '\0') { 4609 bname[0] = '.'; 4610 bname[1] = '\0'; 4611 return (0); 4612 } 4613 4614 /* Strip trailing slashes */ 4615 endp = path + strlen(path) - 1; 4616 while (endp > path && *endp == '/') 4617 endp--; 4618 4619 /* Find the start of the dir */ 4620 while (endp > path && *endp != '/') 4621 endp--; 4622 4623 /* Either the dir is "/" or there are no slashes */ 4624 if (endp == path) { 4625 bname[0] = *endp == '/' ? '/' : '.'; 4626 bname[1] = '\0'; 4627 return (0); 4628 } else { 4629 do { 4630 endp--; 4631 } while (endp > path && *endp == '/'); 4632 } 4633 4634 if (endp - path + 2 > PATH_MAX) { 4635 _rtld_error("Filename is too long: %s", path); 4636 return (-1); 4637 } 4638 4639 strncpy(bname, path, endp - path + 1); 4640 bname[endp - path + 1] = '\0'; 4641 return (0); 4642 } 4643 4644 static int 4645 rtld_dirname_abs(const char *path, char *base) 4646 { 4647 char *last; 4648 4649 if (realpath(path, base) == NULL) { 4650 _rtld_error("realpath \"%s\" failed (%s)", path, 4651 rtld_strerror(errno)); 4652 return (-1); 4653 } 4654 dbg("%s -> %s", path, base); 4655 last = strrchr(base, '/'); 4656 if (last == NULL) { 4657 _rtld_error("non-abs result from realpath \"%s\"", path); 4658 return (-1); 4659 } 4660 if (last != base) 4661 *last = '\0'; 4662 return (0); 4663 } 4664 4665 static void 4666 linkmap_add(Obj_Entry *obj) 4667 { 4668 struct link_map *l, *prev; 4669 4670 l = &obj->linkmap; 4671 l->l_name = obj->path; 4672 l->l_base = obj->mapbase; 4673 l->l_ld = obj->dynamic; 4674 l->l_addr = obj->relocbase; 4675 4676 if (r_debug.r_map == NULL) { 4677 r_debug.r_map = l; 4678 return; 4679 } 4680 4681 /* 4682 * Scan to the end of the list, but not past the entry for the 4683 * dynamic linker, which we want to keep at the very end. 4684 */ 4685 for (prev = r_debug.r_map; 4686 prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap; 4687 prev = prev->l_next) 4688 ; 4689 4690 /* Link in the new entry. */ 4691 l->l_prev = prev; 4692 l->l_next = prev->l_next; 4693 if (l->l_next != NULL) 4694 l->l_next->l_prev = l; 4695 prev->l_next = l; 4696 } 4697 4698 static void 4699 linkmap_delete(Obj_Entry *obj) 4700 { 4701 struct link_map *l; 4702 4703 l = &obj->linkmap; 4704 if (l->l_prev == NULL) { 4705 if ((r_debug.r_map = l->l_next) != NULL) 4706 l->l_next->l_prev = NULL; 4707 return; 4708 } 4709 4710 if ((l->l_prev->l_next = l->l_next) != NULL) 4711 l->l_next->l_prev = l->l_prev; 4712 } 4713 4714 /* 4715 * Function for the debugger to set a breakpoint on to gain control. 4716 * 4717 * The two parameters allow the debugger to easily find and determine 4718 * what the runtime loader is doing and to whom it is doing it. 4719 * 4720 * When the loadhook trap is hit (r_debug_state, set at program 4721 * initialization), the arguments can be found on the stack: 4722 * 4723 * +8 struct link_map *m 4724 * +4 struct r_debug *rd 4725 * +0 RetAddr 4726 */ 4727 void 4728 r_debug_state(struct r_debug *rd __unused, struct link_map *m __unused) 4729 { 4730 /* 4731 * The following is a hack to force the compiler to emit calls to 4732 * this function, even when optimizing. If the function is empty, 4733 * the compiler is not obliged to emit any code for calls to it, 4734 * even when marked __noinline. However, gdb depends on those 4735 * calls being made. 4736 */ 4737 __compiler_membar(); 4738 } 4739 4740 /* 4741 * A function called after init routines have completed. This can be used to 4742 * break before a program's entry routine is called, and can be used when 4743 * main is not available in the symbol table. 4744 */ 4745 void 4746 _r_debug_postinit(struct link_map *m __unused) 4747 { 4748 /* See r_debug_state(). */ 4749 __compiler_membar(); 4750 } 4751 4752 static void 4753 release_object(Obj_Entry *obj) 4754 { 4755 if (obj->holdcount > 0) { 4756 obj->unholdfree = true; 4757 return; 4758 } 4759 munmap(obj->mapbase, obj->mapsize); 4760 linkmap_delete(obj); 4761 obj_free(obj); 4762 } 4763 4764 /* 4765 * Get address of the pointer variable in the main program. 4766 * Prefer non-weak symbol over the weak one. 4767 */ 4768 static const void ** 4769 get_program_var_addr(const char *name, RtldLockState *lockstate) 4770 { 4771 SymLook req; 4772 DoneList donelist; 4773 const void **res; 4774 4775 symlook_init(&req, name); 4776 req.lockstate = lockstate; 4777 donelist_init(&donelist, NULL); 4778 if (symlook_global(&req, &donelist) != 0) 4779 return (NULL); 4780 if (ELF_ST_TYPE(req.sym_out->st_info) == STT_FUNC) 4781 res = (const void **)make_function_pointer(req.sym_out, 4782 req.defobj_out); 4783 else if (ELF_ST_TYPE(req.sym_out->st_info) == STT_GNU_IFUNC) 4784 res = (const void **)rtld_resolve_ifunc(req.defobj_out, 4785 req.sym_out); 4786 else 4787 res = (const void **)(req.defobj_out->relocbase + 4788 req.sym_out->st_value); 4789 donelist_free(&donelist); 4790 return (res); 4791 } 4792 4793 /* 4794 * Set a pointer variable in the main program to the given value. This 4795 * is used to set key variables such as "environ" before any of the 4796 * init functions are called. 4797 */ 4798 static void 4799 set_program_var(const char *name, const void *value) 4800 { 4801 const void **addr; 4802 4803 if ((addr = get_program_var_addr(name, NULL)) != NULL) { 4804 dbg("\"%s\": *%p <-- %p", name, addr, value); 4805 *addr = value; 4806 } 4807 } 4808 4809 /* 4810 * Search the global objects, including dependencies and main object, 4811 * for the given symbol. 4812 */ 4813 static int 4814 symlook_global(SymLook *req, DoneList *donelist) 4815 { 4816 SymLook req1; 4817 const Objlist_Entry *elm; 4818 int res; 4819 4820 symlook_init_from_req(&req1, req); 4821 4822 /* Search all objects loaded at program start up. */ 4823 if (req->defobj_out == NULL || (ld_dynamic_weak && 4824 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK)) { 4825 res = symlook_list(&req1, &list_main, donelist); 4826 if (res == 0 && (!ld_dynamic_weak || req->defobj_out == NULL || 4827 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4828 req->sym_out = req1.sym_out; 4829 req->defobj_out = req1.defobj_out; 4830 assert(req->defobj_out != NULL); 4831 } 4832 } 4833 4834 /* Search all DAGs whose roots are RTLD_GLOBAL objects. */ 4835 STAILQ_FOREACH(elm, &list_global, link) { 4836 if (req->defobj_out != NULL && (!ld_dynamic_weak || 4837 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK)) 4838 break; 4839 res = symlook_list(&req1, &elm->obj->dagmembers, donelist); 4840 if (res == 0 && (req->defobj_out == NULL || 4841 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4842 req->sym_out = req1.sym_out; 4843 req->defobj_out = req1.defobj_out; 4844 assert(req->defobj_out != NULL); 4845 } 4846 } 4847 4848 return (req->sym_out != NULL ? 0 : ESRCH); 4849 } 4850 4851 /* 4852 * Given a symbol name in a referencing object, find the corresponding 4853 * definition of the symbol. Returns a pointer to the symbol, or NULL if 4854 * no definition was found. Returns a pointer to the Obj_Entry of the 4855 * defining object via the reference parameter DEFOBJ_OUT. 4856 */ 4857 static int 4858 symlook_default(SymLook *req, const Obj_Entry *refobj) 4859 { 4860 DoneList donelist; 4861 const Objlist_Entry *elm; 4862 SymLook req1; 4863 int res; 4864 4865 donelist_init(&donelist, req); 4866 symlook_init_from_req(&req1, req); 4867 4868 /* 4869 * Look first in the referencing object if linked symbolically, 4870 * and similarly handle protected symbols. 4871 */ 4872 res = symlook_obj(&req1, refobj); 4873 if (res == 0 && (refobj->symbolic || 4874 ELF_ST_VISIBILITY(req1.sym_out->st_other) == STV_PROTECTED || 4875 refobj->deepbind)) { 4876 req->sym_out = req1.sym_out; 4877 req->defobj_out = req1.defobj_out; 4878 assert(req->defobj_out != NULL); 4879 } 4880 if (refobj->symbolic || req->defobj_out != NULL || refobj->deepbind) 4881 donelist_check(&donelist, refobj); 4882 4883 if (!refobj->deepbind) 4884 symlook_global(req, &donelist); 4885 4886 /* Search all dlopened DAGs containing the referencing object. */ 4887 STAILQ_FOREACH(elm, &refobj->dldags, link) { 4888 if (req->sym_out != NULL && (!ld_dynamic_weak || 4889 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK)) 4890 break; 4891 res = symlook_list(&req1, &elm->obj->dagmembers, &donelist); 4892 if (res == 0 && (req->sym_out == NULL || 4893 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4894 req->sym_out = req1.sym_out; 4895 req->defobj_out = req1.defobj_out; 4896 assert(req->defobj_out != NULL); 4897 } 4898 } 4899 4900 if (refobj->deepbind) 4901 symlook_global(req, &donelist); 4902 4903 /* 4904 * Search the dynamic linker itself, and possibly resolve the 4905 * symbol from there. This is how the application links to 4906 * dynamic linker services such as dlopen. 4907 */ 4908 if (req->sym_out == NULL || 4909 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 4910 res = symlook_obj(&req1, &obj_rtld); 4911 if (res == 0) { 4912 req->sym_out = req1.sym_out; 4913 req->defobj_out = req1.defobj_out; 4914 assert(req->defobj_out != NULL); 4915 } 4916 } 4917 4918 donelist_free(&donelist); 4919 return (req->sym_out != NULL ? 0 : ESRCH); 4920 } 4921 4922 static int 4923 symlook_list(SymLook *req, const Objlist *objlist, DoneList *dlp) 4924 { 4925 const Elf_Sym *def; 4926 const Obj_Entry *defobj; 4927 const Objlist_Entry *elm; 4928 SymLook req1; 4929 int res; 4930 4931 def = NULL; 4932 defobj = NULL; 4933 STAILQ_FOREACH(elm, objlist, link) { 4934 if (donelist_check(dlp, elm->obj)) 4935 continue; 4936 symlook_init_from_req(&req1, req); 4937 if ((res = symlook_obj(&req1, elm->obj)) == 0) { 4938 if (def == NULL || (ld_dynamic_weak && 4939 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4940 def = req1.sym_out; 4941 defobj = req1.defobj_out; 4942 if (!ld_dynamic_weak || 4943 ELF_ST_BIND(def->st_info) != STB_WEAK) 4944 break; 4945 } 4946 } 4947 } 4948 if (def != NULL) { 4949 req->sym_out = def; 4950 req->defobj_out = defobj; 4951 return (0); 4952 } 4953 return (ESRCH); 4954 } 4955 4956 /* 4957 * Search the chain of DAGS cointed to by the given Needed_Entry 4958 * for a symbol of the given name. Each DAG is scanned completely 4959 * before advancing to the next one. Returns a pointer to the symbol, 4960 * or NULL if no definition was found. 4961 */ 4962 static int 4963 symlook_needed(SymLook *req, const Needed_Entry *needed, DoneList *dlp) 4964 { 4965 const Elf_Sym *def; 4966 const Needed_Entry *n; 4967 const Obj_Entry *defobj; 4968 SymLook req1; 4969 int res; 4970 4971 def = NULL; 4972 defobj = NULL; 4973 symlook_init_from_req(&req1, req); 4974 for (n = needed; n != NULL; n = n->next) { 4975 if (n->obj == NULL || (res = symlook_list(&req1, 4976 &n->obj->dagmembers, dlp)) != 0) 4977 continue; 4978 if (def == NULL || (ld_dynamic_weak && 4979 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4980 def = req1.sym_out; 4981 defobj = req1.defobj_out; 4982 if (!ld_dynamic_weak || 4983 ELF_ST_BIND(def->st_info) != STB_WEAK) 4984 break; 4985 } 4986 } 4987 if (def != NULL) { 4988 req->sym_out = def; 4989 req->defobj_out = defobj; 4990 return (0); 4991 } 4992 return (ESRCH); 4993 } 4994 4995 static int 4996 symlook_obj_load_filtees(SymLook *req, SymLook *req1, const Obj_Entry *obj, 4997 Needed_Entry *needed) 4998 { 4999 DoneList donelist; 5000 int flags, res; 5001 5002 flags = (req->flags & SYMLOOK_EARLY) != 0 ? RTLD_LO_EARLY : 0; 5003 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 5004 donelist_init(&donelist, NULL); 5005 symlook_init_from_req(req1, req); 5006 res = symlook_needed(req1, needed, &donelist); 5007 donelist_free(&donelist); 5008 return (res); 5009 } 5010 5011 /* 5012 * Search the symbol table of a single shared object for a symbol of 5013 * the given name and version, if requested. Returns a pointer to the 5014 * symbol, or NULL if no definition was found. If the object is 5015 * filter, return filtered symbol from filtee. 5016 * 5017 * The symbol's hash value is passed in for efficiency reasons; that 5018 * eliminates many recomputations of the hash value. 5019 */ 5020 int 5021 symlook_obj(SymLook *req, const Obj_Entry *obj) 5022 { 5023 SymLook req1; 5024 int res, mres; 5025 5026 /* 5027 * If there is at least one valid hash at this point, we prefer to 5028 * use the faster GNU version if available. 5029 */ 5030 if (obj->valid_hash_gnu) 5031 mres = symlook_obj1_gnu(req, obj); 5032 else if (obj->valid_hash_sysv) 5033 mres = symlook_obj1_sysv(req, obj); 5034 else 5035 return (EINVAL); 5036 5037 if (mres == 0) { 5038 if (obj->needed_filtees != NULL) { 5039 res = symlook_obj_load_filtees(req, &req1, obj, 5040 obj->needed_filtees); 5041 if (res == 0) { 5042 req->sym_out = req1.sym_out; 5043 req->defobj_out = req1.defobj_out; 5044 } 5045 return (res); 5046 } 5047 if (obj->needed_aux_filtees != NULL) { 5048 res = symlook_obj_load_filtees(req, &req1, obj, 5049 obj->needed_aux_filtees); 5050 if (res == 0) { 5051 req->sym_out = req1.sym_out; 5052 req->defobj_out = req1.defobj_out; 5053 return (res); 5054 } 5055 } 5056 } 5057 return (mres); 5058 } 5059 5060 /* Symbol match routine common to both hash functions */ 5061 static bool 5062 matched_symbol(SymLook *req, const Obj_Entry *obj, Sym_Match_Result *result, 5063 const unsigned long symnum) 5064 { 5065 Elf_Versym verndx; 5066 const Elf_Sym *symp; 5067 const char *strp; 5068 5069 symp = obj->symtab + symnum; 5070 strp = obj->strtab + symp->st_name; 5071 5072 switch (ELF_ST_TYPE(symp->st_info)) { 5073 case STT_FUNC: 5074 case STT_NOTYPE: 5075 case STT_OBJECT: 5076 case STT_COMMON: 5077 case STT_GNU_IFUNC: 5078 if (symp->st_value == 0) 5079 return (false); 5080 /* fallthrough */ 5081 case STT_TLS: 5082 if (symp->st_shndx != SHN_UNDEF) 5083 break; 5084 else if (((req->flags & SYMLOOK_IN_PLT) == 0) && 5085 (ELF_ST_TYPE(symp->st_info) == STT_FUNC)) 5086 break; 5087 /* fallthrough */ 5088 default: 5089 return (false); 5090 } 5091 if (req->name[0] != strp[0] || strcmp(req->name, strp) != 0) 5092 return (false); 5093 5094 if (req->ventry == NULL) { 5095 if (obj->versyms != NULL) { 5096 verndx = VER_NDX(obj->versyms[symnum]); 5097 if (verndx > obj->vernum) { 5098 _rtld_error( 5099 "%s: symbol %s references wrong version %d", 5100 obj->path, obj->strtab + symnum, verndx); 5101 return (false); 5102 } 5103 /* 5104 * If we are not called from dlsym (i.e. this 5105 * is a normal relocation from unversioned 5106 * binary), accept the symbol immediately if 5107 * it happens to have first version after this 5108 * shared object became versioned. Otherwise, 5109 * if symbol is versioned and not hidden, 5110 * remember it. If it is the only symbol with 5111 * this name exported by the shared object, it 5112 * will be returned as a match by the calling 5113 * function. If symbol is global (verndx < 2) 5114 * accept it unconditionally. 5115 */ 5116 if ((req->flags & SYMLOOK_DLSYM) == 0 && 5117 verndx == VER_NDX_GIVEN) { 5118 result->sym_out = symp; 5119 return (true); 5120 } else if (verndx >= VER_NDX_GIVEN) { 5121 if ((obj->versyms[symnum] & VER_NDX_HIDDEN) == 5122 0) { 5123 if (result->vsymp == NULL) 5124 result->vsymp = symp; 5125 result->vcount++; 5126 } 5127 return (false); 5128 } 5129 } 5130 result->sym_out = symp; 5131 return (true); 5132 } 5133 if (obj->versyms == NULL) { 5134 if (object_match_name(obj, req->ventry->name)) { 5135 _rtld_error( 5136 "%s: object %s should provide version %s for symbol %s", 5137 obj_rtld.path, obj->path, req->ventry->name, 5138 obj->strtab + symnum); 5139 return (false); 5140 } 5141 } else { 5142 verndx = VER_NDX(obj->versyms[symnum]); 5143 if (verndx > obj->vernum) { 5144 _rtld_error("%s: symbol %s references wrong version %d", 5145 obj->path, obj->strtab + symnum, verndx); 5146 return (false); 5147 } 5148 if (obj->vertab[verndx].hash != req->ventry->hash || 5149 strcmp(obj->vertab[verndx].name, req->ventry->name)) { 5150 /* 5151 * Version does not match. Look if this is a 5152 * global symbol and if it is not hidden. If 5153 * global symbol (verndx < 2) is available, 5154 * use it. Do not return symbol if we are 5155 * called by dlvsym, because dlvsym looks for 5156 * a specific version and default one is not 5157 * what dlvsym wants. 5158 */ 5159 if ((req->flags & SYMLOOK_DLSYM) || 5160 (verndx >= VER_NDX_GIVEN) || 5161 (obj->versyms[symnum] & VER_NDX_HIDDEN)) 5162 return (false); 5163 } 5164 } 5165 result->sym_out = symp; 5166 return (true); 5167 } 5168 5169 /* 5170 * Search for symbol using SysV hash function. 5171 * obj->buckets is known not to be NULL at this point; the test for this was 5172 * performed with the obj->valid_hash_sysv assignment. 5173 */ 5174 static int 5175 symlook_obj1_sysv(SymLook *req, const Obj_Entry *obj) 5176 { 5177 unsigned long symnum; 5178 Sym_Match_Result matchres; 5179 5180 matchres.sym_out = NULL; 5181 matchres.vsymp = NULL; 5182 matchres.vcount = 0; 5183 5184 for (symnum = obj->buckets[req->hash % obj->nbuckets]; 5185 symnum != STN_UNDEF; symnum = obj->chains[symnum]) { 5186 if (symnum >= obj->nchains) 5187 return (ESRCH); /* Bad object */ 5188 5189 if (matched_symbol(req, obj, &matchres, symnum)) { 5190 req->sym_out = matchres.sym_out; 5191 req->defobj_out = obj; 5192 return (0); 5193 } 5194 } 5195 if (matchres.vcount == 1) { 5196 req->sym_out = matchres.vsymp; 5197 req->defobj_out = obj; 5198 return (0); 5199 } 5200 return (ESRCH); 5201 } 5202 5203 /* Search for symbol using GNU hash function */ 5204 static int 5205 symlook_obj1_gnu(SymLook *req, const Obj_Entry *obj) 5206 { 5207 Elf_Addr bloom_word; 5208 const Elf32_Word *hashval; 5209 Elf32_Word bucket; 5210 Sym_Match_Result matchres; 5211 unsigned int h1, h2; 5212 unsigned long symnum; 5213 5214 matchres.sym_out = NULL; 5215 matchres.vsymp = NULL; 5216 matchres.vcount = 0; 5217 5218 /* Pick right bitmask word from Bloom filter array */ 5219 bloom_word = obj->bloom_gnu[(req->hash_gnu / __ELF_WORD_SIZE) & 5220 obj->maskwords_bm_gnu]; 5221 5222 /* Calculate modulus word size of gnu hash and its derivative */ 5223 h1 = req->hash_gnu & (__ELF_WORD_SIZE - 1); 5224 h2 = ((req->hash_gnu >> obj->shift2_gnu) & (__ELF_WORD_SIZE - 1)); 5225 5226 /* Filter out the "definitely not in set" queries */ 5227 if (((bloom_word >> h1) & (bloom_word >> h2) & 1) == 0) 5228 return (ESRCH); 5229 5230 /* Locate hash chain and corresponding value element*/ 5231 bucket = obj->buckets_gnu[req->hash_gnu % obj->nbuckets_gnu]; 5232 if (bucket == 0) 5233 return (ESRCH); 5234 hashval = &obj->chain_zero_gnu[bucket]; 5235 do { 5236 if (((*hashval ^ req->hash_gnu) >> 1) == 0) { 5237 symnum = hashval - obj->chain_zero_gnu; 5238 if (matched_symbol(req, obj, &matchres, symnum)) { 5239 req->sym_out = matchres.sym_out; 5240 req->defobj_out = obj; 5241 return (0); 5242 } 5243 } 5244 } while ((*hashval++ & 1) == 0); 5245 if (matchres.vcount == 1) { 5246 req->sym_out = matchres.vsymp; 5247 req->defobj_out = obj; 5248 return (0); 5249 } 5250 return (ESRCH); 5251 } 5252 5253 static void 5254 trace_calc_fmts(const char **main_local, const char **fmt1, const char **fmt2) 5255 { 5256 *main_local = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_PROGNAME); 5257 if (*main_local == NULL) 5258 *main_local = ""; 5259 5260 *fmt1 = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_FMT1); 5261 if (*fmt1 == NULL) 5262 *fmt1 = "\t%o => %p (%x)\n"; 5263 5264 *fmt2 = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_FMT2); 5265 if (*fmt2 == NULL) 5266 *fmt2 = "\t%o (%x)\n"; 5267 } 5268 5269 static void 5270 trace_print_obj(Obj_Entry *obj, const char *name, const char *path, 5271 const char *main_local, const char *fmt1, const char *fmt2) 5272 { 5273 const char *fmt; 5274 int c; 5275 5276 if (fmt1 == NULL) 5277 fmt = fmt2; 5278 else 5279 /* XXX bogus */ 5280 fmt = strncmp(name, "lib", 3) == 0 ? fmt1 : fmt2; 5281 5282 while ((c = *fmt++) != '\0') { 5283 switch (c) { 5284 default: 5285 rtld_putchar(c); 5286 continue; 5287 case '\\': 5288 switch (c = *fmt) { 5289 case '\0': 5290 continue; 5291 case 'n': 5292 rtld_putchar('\n'); 5293 break; 5294 case 't': 5295 rtld_putchar('\t'); 5296 break; 5297 } 5298 break; 5299 case '%': 5300 switch (c = *fmt) { 5301 case '\0': 5302 continue; 5303 case '%': 5304 default: 5305 rtld_putchar(c); 5306 break; 5307 case 'A': 5308 rtld_putstr(main_local); 5309 break; 5310 case 'a': 5311 rtld_putstr(obj_main->path); 5312 break; 5313 case 'o': 5314 rtld_putstr(name); 5315 break; 5316 case 'p': 5317 rtld_putstr(path); 5318 break; 5319 case 'x': 5320 rtld_printf("%p", 5321 obj != NULL ? obj->mapbase : NULL); 5322 break; 5323 } 5324 break; 5325 } 5326 ++fmt; 5327 } 5328 } 5329 5330 static void 5331 trace_loaded_objects(Obj_Entry *obj, bool show_preload) 5332 { 5333 const char *fmt1, *fmt2, *main_local; 5334 const char *name, *path; 5335 bool first_spurious, list_containers; 5336 5337 trace_calc_fmts(&main_local, &fmt1, &fmt2); 5338 list_containers = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_ALL) != NULL; 5339 5340 for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 5341 Needed_Entry *needed; 5342 5343 if (obj->marker) 5344 continue; 5345 if (list_containers && obj->needed != NULL) 5346 rtld_printf("%s:\n", obj->path); 5347 for (needed = obj->needed; needed; needed = needed->next) { 5348 if (needed->obj != NULL) { 5349 if (needed->obj->traced && !list_containers) 5350 continue; 5351 needed->obj->traced = true; 5352 path = needed->obj->path; 5353 } else 5354 path = "not found"; 5355 5356 name = obj->strtab + needed->name; 5357 trace_print_obj(needed->obj, name, path, main_local, 5358 fmt1, fmt2); 5359 } 5360 } 5361 5362 if (show_preload) { 5363 if (ld_get_env_var(LD_TRACE_LOADED_OBJECTS_FMT2) == NULL) 5364 fmt2 = "\t%p (%x)\n"; 5365 first_spurious = true; 5366 5367 TAILQ_FOREACH(obj, &obj_list, next) { 5368 if (obj->marker || obj == obj_main || obj->traced) 5369 continue; 5370 5371 if (list_containers && first_spurious) { 5372 rtld_printf("[preloaded]\n"); 5373 first_spurious = false; 5374 } 5375 5376 Name_Entry *fname = STAILQ_FIRST(&obj->names); 5377 name = fname == NULL ? "<unknown>" : fname->name; 5378 trace_print_obj(obj, name, obj->path, main_local, NULL, 5379 fmt2); 5380 } 5381 } 5382 } 5383 5384 /* 5385 * Unload a dlopened object and its dependencies from memory and from 5386 * our data structures. It is assumed that the DAG rooted in the 5387 * object has already been unreferenced, and that the object has a 5388 * reference count of 0. 5389 */ 5390 static void 5391 unload_object(Obj_Entry *root, RtldLockState *lockstate) 5392 { 5393 Obj_Entry marker, *obj, *next; 5394 5395 assert(root->refcount == 0); 5396 5397 /* 5398 * Pass over the DAG removing unreferenced objects from 5399 * appropriate lists. 5400 */ 5401 unlink_object(root); 5402 5403 /* Unmap all objects that are no longer referenced. */ 5404 for (obj = TAILQ_FIRST(&obj_list); obj != NULL; obj = next) { 5405 next = TAILQ_NEXT(obj, next); 5406 if (obj->marker || obj->refcount != 0) 5407 continue; 5408 LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 5409 0, obj->path); 5410 dbg("unloading \"%s\"", obj->path); 5411 /* 5412 * Unlink the object now to prevent new references from 5413 * being acquired while the bind lock is dropped in 5414 * recursive dlclose() invocations. 5415 */ 5416 TAILQ_REMOVE(&obj_list, obj, next); 5417 obj_count--; 5418 5419 if (obj->filtees_loaded) { 5420 if (next != NULL) { 5421 init_marker(&marker); 5422 TAILQ_INSERT_BEFORE(next, &marker, next); 5423 unload_filtees(obj, lockstate); 5424 next = TAILQ_NEXT(&marker, next); 5425 TAILQ_REMOVE(&obj_list, &marker, next); 5426 } else 5427 unload_filtees(obj, lockstate); 5428 } 5429 release_object(obj); 5430 } 5431 } 5432 5433 static void 5434 unlink_object(Obj_Entry *root) 5435 { 5436 Objlist_Entry *elm; 5437 5438 if (root->refcount == 0) { 5439 /* Remove the object from the RTLD_GLOBAL list. */ 5440 objlist_remove(&list_global, root); 5441 5442 /* Remove the object from all objects' DAG lists. */ 5443 STAILQ_FOREACH(elm, &root->dagmembers, link) { 5444 objlist_remove(&elm->obj->dldags, root); 5445 if (elm->obj != root) 5446 unlink_object(elm->obj); 5447 } 5448 } 5449 } 5450 5451 static void 5452 ref_dag(Obj_Entry *root) 5453 { 5454 Objlist_Entry *elm; 5455 5456 assert(root->dag_inited); 5457 STAILQ_FOREACH(elm, &root->dagmembers, link) 5458 elm->obj->refcount++; 5459 } 5460 5461 static void 5462 unref_dag(Obj_Entry *root) 5463 { 5464 Objlist_Entry *elm; 5465 5466 assert(root->dag_inited); 5467 STAILQ_FOREACH(elm, &root->dagmembers, link) 5468 elm->obj->refcount--; 5469 } 5470 5471 /* 5472 * Common code for MD __tls_get_addr(). 5473 * 5474 * The tcb->tcb_dtv data structure is thread-local. The reason that 5475 * the function needs to take the rtld_bind_lock exclusive (as opposed 5476 * to only shared, to safely access obj_list in allocate_module_tls()) 5477 * is to protect the rtld_malloc data. 5478 */ 5479 static void * 5480 tls_get_addr_slow(struct tcb *tcb, int index, size_t offset, bool locked) 5481 { 5482 struct dtv *newdtv, *dtv; 5483 RtldLockState lockstate; 5484 int to_copy; 5485 5486 dtv = tcb->tcb_dtv; 5487 /* Check dtv generation in case new modules have arrived */ 5488 if (dtv->dtv_gen != tls_dtv_generation) { 5489 if (!locked) 5490 wlock_acquire(rtld_bind_lock, &lockstate); 5491 newdtv = xcalloc(1, sizeof(struct dtv) + tls_max_index * 5492 sizeof(struct dtv_slot)); 5493 to_copy = dtv->dtv_size; 5494 if (to_copy > tls_max_index) 5495 to_copy = tls_max_index; 5496 memcpy(newdtv->dtv_slots, dtv->dtv_slots, to_copy * 5497 sizeof(struct dtv_slot)); 5498 newdtv->dtv_gen = tls_dtv_generation; 5499 newdtv->dtv_size = tls_max_index; 5500 free(dtv); 5501 if (!locked) 5502 lock_release(rtld_bind_lock, &lockstate); 5503 dtv = tcb->tcb_dtv = newdtv; 5504 } 5505 5506 /* Dynamically allocate module TLS if necessary */ 5507 if (dtv->dtv_slots[index - 1].dtvs_tls == 0) { 5508 /* Signal safe, wlock will block out signals. */ 5509 if (!locked) 5510 wlock_acquire(rtld_bind_lock, &lockstate); 5511 if (!dtv->dtv_slots[index - 1].dtvs_tls) 5512 dtv->dtv_slots[index - 1].dtvs_tls = 5513 allocate_module_tls(tcb, index); 5514 if (!locked) 5515 lock_release(rtld_bind_lock, &lockstate); 5516 } 5517 return (dtv->dtv_slots[index - 1].dtvs_tls + offset); 5518 } 5519 5520 void * 5521 tls_get_addr_common(struct tcb *tcb, int index, size_t offset) 5522 { 5523 struct dtv *dtv; 5524 5525 dtv = tcb->tcb_dtv; 5526 /* Check dtv generation in case new modules have arrived */ 5527 if (__predict_true(dtv->dtv_gen == tls_dtv_generation && 5528 dtv->dtv_slots[index - 1].dtvs_tls != 0)) 5529 return (dtv->dtv_slots[index - 1].dtvs_tls + offset); 5530 return (tls_get_addr_slow(tcb, index, offset, false)); 5531 } 5532 5533 static struct tcb * 5534 tcb_from_tcb_list_entry(struct tcb_list_entry *tcbelm) 5535 { 5536 #ifdef TLS_VARIANT_I 5537 return ((struct tcb *)((char *)tcbelm - tcb_list_entry_offset)); 5538 #else 5539 return ((struct tcb *)((char *)tcbelm + tcb_list_entry_offset)); 5540 #endif 5541 } 5542 5543 static struct tcb_list_entry * 5544 tcb_list_entry_from_tcb(struct tcb *tcb) 5545 { 5546 #ifdef TLS_VARIANT_I 5547 return ((struct tcb_list_entry *)((char *)tcb + tcb_list_entry_offset)); 5548 #else 5549 return ((struct tcb_list_entry *)((char *)tcb - tcb_list_entry_offset)); 5550 #endif 5551 } 5552 5553 static void 5554 tcb_list_insert(struct tcb *tcb) 5555 { 5556 struct tcb_list_entry *tcbelm; 5557 5558 tcbelm = tcb_list_entry_from_tcb(tcb); 5559 TAILQ_INSERT_TAIL(&tcb_list, tcbelm, next); 5560 } 5561 5562 static void 5563 tcb_list_remove(struct tcb *tcb) 5564 { 5565 struct tcb_list_entry *tcbelm; 5566 5567 tcbelm = tcb_list_entry_from_tcb(tcb); 5568 TAILQ_REMOVE(&tcb_list, tcbelm, next); 5569 } 5570 5571 #ifdef TLS_VARIANT_I 5572 5573 /* 5574 * Return pointer to allocated TLS block 5575 */ 5576 static void * 5577 get_tls_block_ptr(void *tcb, size_t tcbsize) 5578 { 5579 size_t extra_size, post_size, pre_size, tls_block_size; 5580 size_t tls_init_align; 5581 5582 tls_init_align = MAX(obj_main->tlsalign, 1); 5583 5584 /* Compute fragments sizes. */ 5585 extra_size = tcbsize - TLS_TCB_SIZE; 5586 post_size = calculate_tls_post_size(tls_init_align); 5587 tls_block_size = tcbsize + post_size; 5588 pre_size = roundup2(tls_block_size, tls_init_align) - tls_block_size; 5589 5590 return ((char *)tcb - pre_size - extra_size); 5591 } 5592 5593 /* 5594 * Allocate Static TLS using the Variant I method. 5595 * 5596 * For details on the layout, see lib/libc/gen/tls.c. 5597 * 5598 * NB: rtld's tls_static_space variable includes TLS_TCB_SIZE and post_size as 5599 * it is based on tls_last_offset, and TLS offsets here are really TCB 5600 * offsets, whereas libc's tls_static_space is just the executable's static 5601 * TLS segment. 5602 * 5603 * NB: This differs from NetBSD's ld.elf_so, where TLS offsets are relative to 5604 * the end of the TCB. 5605 */ 5606 void * 5607 allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign) 5608 { 5609 Obj_Entry *obj; 5610 char *tls_block; 5611 struct dtv *dtv; 5612 struct tcb *tcb; 5613 char *addr; 5614 size_t i; 5615 size_t extra_size, maxalign, post_size, pre_size, tls_block_size; 5616 size_t tls_init_align, tls_init_offset, tls_bss_offset; 5617 5618 if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE) 5619 return (oldtcb); 5620 5621 assert(tcbsize >= TLS_TCB_SIZE); 5622 maxalign = MAX(tcbalign, tls_static_max_align); 5623 tls_init_align = MAX(obj_main->tlsalign, 1); 5624 5625 /* Compute fragments sizes. */ 5626 extra_size = tcbsize - TLS_TCB_SIZE; 5627 post_size = calculate_tls_post_size(tls_init_align); 5628 tls_block_size = tcbsize + post_size; 5629 pre_size = roundup2(tls_block_size, tls_init_align) - tls_block_size; 5630 tls_block_size += pre_size + tls_static_space - TLS_TCB_SIZE - 5631 post_size; 5632 5633 /* Allocate whole TLS block */ 5634 tls_block = xmalloc_aligned(tls_block_size, maxalign, 0); 5635 tcb = (struct tcb *)(tls_block + pre_size + extra_size); 5636 5637 if (oldtcb != NULL) { 5638 memcpy(tls_block, get_tls_block_ptr(oldtcb, tcbsize), 5639 tls_static_space); 5640 free(get_tls_block_ptr(oldtcb, tcbsize)); 5641 5642 /* Adjust the DTV. */ 5643 dtv = tcb->tcb_dtv; 5644 for (i = 0; i < dtv->dtv_size; i++) { 5645 if ((uintptr_t)dtv->dtv_slots[i].dtvs_tls >= 5646 (uintptr_t)oldtcb && 5647 (uintptr_t)dtv->dtv_slots[i].dtvs_tls < 5648 (uintptr_t)oldtcb + tls_static_space) { 5649 dtv->dtv_slots[i].dtvs_tls = (char *)tcb + 5650 (dtv->dtv_slots[i].dtvs_tls - 5651 (char *)oldtcb); 5652 } 5653 } 5654 } else { 5655 dtv = xcalloc(1, sizeof(struct dtv) + tls_max_index * 5656 sizeof(struct dtv_slot)); 5657 tcb->tcb_dtv = dtv; 5658 dtv->dtv_gen = tls_dtv_generation; 5659 dtv->dtv_size = tls_max_index; 5660 5661 for (obj = globallist_curr(objs); obj != NULL; 5662 obj = globallist_next(obj)) { 5663 if (obj->tlsoffset == 0) 5664 continue; 5665 tls_init_offset = obj->tlspoffset & (obj->tlsalign - 1); 5666 addr = (char *)tcb + obj->tlsoffset; 5667 if (tls_init_offset > 0) 5668 memset(addr, 0, tls_init_offset); 5669 if (obj->tlsinitsize > 0) { 5670 memcpy(addr + tls_init_offset, obj->tlsinit, 5671 obj->tlsinitsize); 5672 } 5673 if (obj->tlssize > obj->tlsinitsize) { 5674 tls_bss_offset = tls_init_offset + 5675 obj->tlsinitsize; 5676 memset(addr + tls_bss_offset, 0, 5677 obj->tlssize - tls_bss_offset); 5678 } 5679 dtv->dtv_slots[obj->tlsindex - 1].dtvs_tls = addr; 5680 } 5681 } 5682 5683 tcb_list_insert(tcb); 5684 return (tcb); 5685 } 5686 5687 void 5688 free_tls(void *tcb, size_t tcbsize, size_t tcbalign __unused) 5689 { 5690 struct dtv *dtv; 5691 uintptr_t tlsstart, tlsend; 5692 size_t post_size; 5693 size_t i, tls_init_align __unused; 5694 5695 tcb_list_remove(tcb); 5696 5697 assert(tcbsize >= TLS_TCB_SIZE); 5698 tls_init_align = MAX(obj_main->tlsalign, 1); 5699 5700 /* Compute fragments sizes. */ 5701 post_size = calculate_tls_post_size(tls_init_align); 5702 5703 tlsstart = (uintptr_t)tcb + TLS_TCB_SIZE + post_size; 5704 tlsend = (uintptr_t)tcb + tls_static_space; 5705 5706 dtv = ((struct tcb *)tcb)->tcb_dtv; 5707 for (i = 0; i < dtv->dtv_size; i++) { 5708 if (dtv->dtv_slots[i].dtvs_tls != NULL && 5709 ((uintptr_t)dtv->dtv_slots[i].dtvs_tls < tlsstart || 5710 (uintptr_t)dtv->dtv_slots[i].dtvs_tls >= tlsend)) { 5711 free(dtv->dtv_slots[i].dtvs_tls); 5712 } 5713 } 5714 free(dtv); 5715 free(get_tls_block_ptr(tcb, tcbsize)); 5716 } 5717 5718 #endif /* TLS_VARIANT_I */ 5719 5720 #ifdef TLS_VARIANT_II 5721 5722 /* 5723 * Allocate Static TLS using the Variant II method. 5724 */ 5725 void * 5726 allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign) 5727 { 5728 Obj_Entry *obj; 5729 size_t size, ralign; 5730 char *tls_block; 5731 struct dtv *dtv, *olddtv; 5732 struct tcb *tcb; 5733 char *addr; 5734 size_t i; 5735 5736 ralign = tcbalign; 5737 if (tls_static_max_align > ralign) 5738 ralign = tls_static_max_align; 5739 size = roundup(tls_static_space, ralign) + roundup(tcbsize, ralign); 5740 5741 assert(tcbsize >= 2 * sizeof(uintptr_t)); 5742 tls_block = xmalloc_aligned(size, ralign, 0 /* XXX */); 5743 dtv = xcalloc(1, sizeof(struct dtv) + tls_max_index * 5744 sizeof(struct dtv_slot)); 5745 5746 tcb = (struct tcb *)(tls_block + roundup(tls_static_space, ralign)); 5747 tcb->tcb_self = tcb; 5748 tcb->tcb_dtv = dtv; 5749 5750 dtv->dtv_gen = tls_dtv_generation; 5751 dtv->dtv_size = tls_max_index; 5752 5753 if (oldtcb != NULL) { 5754 /* 5755 * Copy the static TLS block over whole. 5756 */ 5757 memcpy((char *)tcb - tls_static_space, 5758 (const char *)oldtcb - tls_static_space, 5759 tls_static_space); 5760 5761 /* 5762 * If any dynamic TLS blocks have been created tls_get_addr(), 5763 * move them over. 5764 */ 5765 olddtv = ((struct tcb *)oldtcb)->tcb_dtv; 5766 for (i = 0; i < olddtv->dtv_size; i++) { 5767 if ((uintptr_t)olddtv->dtv_slots[i].dtvs_tls < 5768 (uintptr_t)oldtcb - size || 5769 (uintptr_t)olddtv->dtv_slots[i].dtvs_tls > 5770 (uintptr_t)oldtcb) { 5771 dtv->dtv_slots[i].dtvs_tls = 5772 olddtv->dtv_slots[i].dtvs_tls; 5773 olddtv->dtv_slots[i].dtvs_tls = NULL; 5774 } 5775 } 5776 5777 /* 5778 * We assume that this block was the one we created with 5779 * allocate_initial_tls(). 5780 */ 5781 free_tls(oldtcb, 2 * sizeof(uintptr_t), sizeof(uintptr_t)); 5782 } else { 5783 for (obj = objs; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 5784 if (obj->marker || obj->tlsoffset == 0) 5785 continue; 5786 addr = (char *)tcb - obj->tlsoffset; 5787 memset(addr + obj->tlsinitsize, 0, obj->tlssize - 5788 obj->tlsinitsize); 5789 if (obj->tlsinit) { 5790 memcpy(addr, obj->tlsinit, obj->tlsinitsize); 5791 obj->static_tls_copied = true; 5792 } 5793 dtv->dtv_slots[obj->tlsindex - 1].dtvs_tls = addr; 5794 } 5795 } 5796 5797 tcb_list_insert(tcb); 5798 return (tcb); 5799 } 5800 5801 void 5802 free_tls(void *tcb, size_t tcbsize __unused, size_t tcbalign) 5803 { 5804 struct dtv *dtv; 5805 size_t size, ralign; 5806 size_t i; 5807 uintptr_t tlsstart, tlsend; 5808 5809 tcb_list_remove(tcb); 5810 5811 /* 5812 * Figure out the size of the initial TLS block so that we can 5813 * find stuff which ___tls_get_addr() allocated dynamically. 5814 */ 5815 ralign = tcbalign; 5816 if (tls_static_max_align > ralign) 5817 ralign = tls_static_max_align; 5818 size = roundup(tls_static_space, ralign); 5819 5820 dtv = ((struct tcb *)tcb)->tcb_dtv; 5821 tlsend = (uintptr_t)tcb; 5822 tlsstart = tlsend - size; 5823 for (i = 0; i < dtv->dtv_size; i++) { 5824 if (dtv->dtv_slots[i].dtvs_tls != NULL && 5825 ((uintptr_t)dtv->dtv_slots[i].dtvs_tls < tlsstart || 5826 (uintptr_t)dtv->dtv_slots[i].dtvs_tls > tlsend)) { 5827 free(dtv->dtv_slots[i].dtvs_tls); 5828 } 5829 } 5830 5831 free((void *)tlsstart); 5832 free(dtv); 5833 } 5834 5835 #endif /* TLS_VARIANT_II */ 5836 5837 /* 5838 * Allocate TLS block for module with given index. 5839 */ 5840 void * 5841 allocate_module_tls(struct tcb *tcb, int index) 5842 { 5843 Obj_Entry *obj; 5844 char *p; 5845 5846 TAILQ_FOREACH(obj, &obj_list, next) { 5847 if (obj->marker) 5848 continue; 5849 if (obj->tlsindex == index) 5850 break; 5851 } 5852 if (obj == NULL) { 5853 _rtld_error("Can't find module with TLS index %d", index); 5854 rtld_die(); 5855 } 5856 5857 if (obj->tls_static) { 5858 #ifdef TLS_VARIANT_I 5859 p = (char *)tcb + obj->tlsoffset; 5860 #else 5861 p = (char *)tcb - obj->tlsoffset; 5862 #endif 5863 return (p); 5864 } 5865 5866 obj->tls_dynamic = true; 5867 5868 p = xmalloc_aligned(obj->tlssize, obj->tlsalign, obj->tlspoffset); 5869 memcpy(p, obj->tlsinit, obj->tlsinitsize); 5870 memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize); 5871 return (p); 5872 } 5873 5874 static bool 5875 allocate_tls_offset_common(size_t *offp, size_t tlssize, size_t tlsalign, 5876 size_t tlspoffset __unused) 5877 { 5878 size_t off; 5879 5880 if (tls_last_offset == 0) 5881 off = calculate_first_tls_offset(tlssize, tlsalign, 5882 tlspoffset); 5883 else 5884 off = calculate_tls_offset(tls_last_offset, tls_last_size, 5885 tlssize, tlsalign, tlspoffset); 5886 5887 *offp = off; 5888 #ifdef TLS_VARIANT_I 5889 off += tlssize; 5890 #endif 5891 5892 /* 5893 * If we have already fixed the size of the static TLS block, we 5894 * must stay within that size. When allocating the static TLS, we 5895 * leave a small amount of space spare to be used for dynamically 5896 * loading modules which use static TLS. 5897 */ 5898 if (tls_static_space != 0) { 5899 if (off > tls_static_space) 5900 return (false); 5901 } else if (tlsalign > tls_static_max_align) { 5902 tls_static_max_align = tlsalign; 5903 } 5904 5905 tls_last_offset = off; 5906 tls_last_size = tlssize; 5907 5908 return (true); 5909 } 5910 5911 bool 5912 allocate_tls_offset(Obj_Entry *obj) 5913 { 5914 if (obj->tls_dynamic) 5915 return (false); 5916 5917 if (obj->tls_static) 5918 return (true); 5919 5920 if (obj->tlssize == 0) { 5921 obj->tls_static = true; 5922 return (true); 5923 } 5924 5925 if (!allocate_tls_offset_common(&obj->tlsoffset, obj->tlssize, 5926 obj->tlsalign, obj->tlspoffset)) 5927 return (false); 5928 5929 obj->tls_static = true; 5930 5931 return (true); 5932 } 5933 5934 void 5935 free_tls_offset(Obj_Entry *obj) 5936 { 5937 /* 5938 * If we were the last thing to allocate out of the static TLS 5939 * block, we give our space back to the 'allocator'. This is a 5940 * simplistic workaround to allow libGL.so.1 to be loaded and 5941 * unloaded multiple times. 5942 */ 5943 size_t off = obj->tlsoffset; 5944 5945 #ifdef TLS_VARIANT_I 5946 off += obj->tlssize; 5947 #endif 5948 if (off == tls_last_offset) { 5949 tls_last_offset -= obj->tlssize; 5950 tls_last_size = 0; 5951 } 5952 } 5953 5954 void * 5955 _rtld_allocate_tls(void *oldtcb, size_t tcbsize, size_t tcbalign) 5956 { 5957 void *ret; 5958 RtldLockState lockstate; 5959 5960 wlock_acquire(rtld_bind_lock, &lockstate); 5961 ret = allocate_tls(globallist_curr(TAILQ_FIRST(&obj_list)), oldtcb, 5962 tcbsize, tcbalign); 5963 lock_release(rtld_bind_lock, &lockstate); 5964 return (ret); 5965 } 5966 5967 void 5968 _rtld_free_tls(void *tcb, size_t tcbsize, size_t tcbalign) 5969 { 5970 RtldLockState lockstate; 5971 5972 wlock_acquire(rtld_bind_lock, &lockstate); 5973 free_tls(tcb, tcbsize, tcbalign); 5974 lock_release(rtld_bind_lock, &lockstate); 5975 } 5976 5977 static void 5978 object_add_name(Obj_Entry *obj, const char *name) 5979 { 5980 Name_Entry *entry; 5981 size_t len; 5982 5983 len = strlen(name); 5984 entry = malloc(sizeof(Name_Entry) + len); 5985 5986 if (entry != NULL) { 5987 strcpy(entry->name, name); 5988 STAILQ_INSERT_TAIL(&obj->names, entry, link); 5989 } 5990 } 5991 5992 static int 5993 object_match_name(const Obj_Entry *obj, const char *name) 5994 { 5995 Name_Entry *entry; 5996 5997 STAILQ_FOREACH(entry, &obj->names, link) { 5998 if (strcmp(name, entry->name) == 0) 5999 return (1); 6000 } 6001 return (0); 6002 } 6003 6004 static Obj_Entry * 6005 locate_dependency(const Obj_Entry *obj, const char *name) 6006 { 6007 const Objlist_Entry *entry; 6008 const Needed_Entry *needed; 6009 6010 STAILQ_FOREACH(entry, &list_main, link) { 6011 if (object_match_name(entry->obj, name)) 6012 return (entry->obj); 6013 } 6014 6015 for (needed = obj->needed; needed != NULL; needed = needed->next) { 6016 if (strcmp(obj->strtab + needed->name, name) == 0 || 6017 (needed->obj != NULL && object_match_name(needed->obj, 6018 name))) { 6019 /* 6020 * If there is DT_NEEDED for the name we are looking 6021 * for, we are all set. Note that object might not be 6022 * found if dependency was not loaded yet, so the 6023 * function can return NULL here. This is expected and 6024 * handled properly by the caller. 6025 */ 6026 return (needed->obj); 6027 } 6028 } 6029 _rtld_error("%s: Unexpected inconsistency: dependency %s not found", 6030 obj->path, name); 6031 rtld_die(); 6032 } 6033 6034 static int 6035 check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj, 6036 const Elf_Vernaux *vna) 6037 { 6038 const Elf_Verdef *vd; 6039 const char *vername; 6040 6041 vername = refobj->strtab + vna->vna_name; 6042 vd = depobj->verdef; 6043 if (vd == NULL) { 6044 _rtld_error("%s: version %s required by %s not defined", 6045 depobj->path, vername, refobj->path); 6046 return (-1); 6047 } 6048 for (;;) { 6049 if (vd->vd_version != VER_DEF_CURRENT) { 6050 _rtld_error( 6051 "%s: Unsupported version %d of Elf_Verdef entry", 6052 depobj->path, vd->vd_version); 6053 return (-1); 6054 } 6055 if (vna->vna_hash == vd->vd_hash) { 6056 const Elf_Verdaux *aux = 6057 (const Elf_Verdaux *)((const char *)vd + 6058 vd->vd_aux); 6059 if (strcmp(vername, depobj->strtab + aux->vda_name) == 6060 0) 6061 return (0); 6062 } 6063 if (vd->vd_next == 0) 6064 break; 6065 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 6066 } 6067 if (vna->vna_flags & VER_FLG_WEAK) 6068 return (0); 6069 _rtld_error("%s: version %s required by %s not found", depobj->path, 6070 vername, refobj->path); 6071 return (-1); 6072 } 6073 6074 static int 6075 rtld_verify_object_versions(Obj_Entry *obj) 6076 { 6077 const Elf_Verneed *vn; 6078 const Elf_Verdef *vd; 6079 const Elf_Verdaux *vda; 6080 const Elf_Vernaux *vna; 6081 const Obj_Entry *depobj; 6082 int maxvernum, vernum; 6083 6084 if (obj->ver_checked) 6085 return (0); 6086 obj->ver_checked = true; 6087 6088 maxvernum = 0; 6089 /* 6090 * Walk over defined and required version records and figure out 6091 * max index used by any of them. Do very basic sanity checking 6092 * while there. 6093 */ 6094 vn = obj->verneed; 6095 while (vn != NULL) { 6096 if (vn->vn_version != VER_NEED_CURRENT) { 6097 _rtld_error( 6098 "%s: Unsupported version %d of Elf_Verneed entry", 6099 obj->path, vn->vn_version); 6100 return (-1); 6101 } 6102 vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux); 6103 for (;;) { 6104 vernum = VER_NEED_IDX(vna->vna_other); 6105 if (vernum > maxvernum) 6106 maxvernum = vernum; 6107 if (vna->vna_next == 0) 6108 break; 6109 vna = (const Elf_Vernaux *)((const char *)vna + 6110 vna->vna_next); 6111 } 6112 if (vn->vn_next == 0) 6113 break; 6114 vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next); 6115 } 6116 6117 vd = obj->verdef; 6118 while (vd != NULL) { 6119 if (vd->vd_version != VER_DEF_CURRENT) { 6120 _rtld_error( 6121 "%s: Unsupported version %d of Elf_Verdef entry", 6122 obj->path, vd->vd_version); 6123 return (-1); 6124 } 6125 vernum = VER_DEF_IDX(vd->vd_ndx); 6126 if (vernum > maxvernum) 6127 maxvernum = vernum; 6128 if (vd->vd_next == 0) 6129 break; 6130 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 6131 } 6132 6133 if (maxvernum == 0) 6134 return (0); 6135 6136 /* 6137 * Store version information in array indexable by version index. 6138 * Verify that object version requirements are satisfied along the 6139 * way. 6140 */ 6141 obj->vernum = maxvernum + 1; 6142 obj->vertab = xcalloc(obj->vernum, sizeof(Ver_Entry)); 6143 6144 vd = obj->verdef; 6145 while (vd != NULL) { 6146 if ((vd->vd_flags & VER_FLG_BASE) == 0) { 6147 vernum = VER_DEF_IDX(vd->vd_ndx); 6148 assert(vernum <= maxvernum); 6149 vda = (const Elf_Verdaux *)((const char *)vd + 6150 vd->vd_aux); 6151 obj->vertab[vernum].hash = vd->vd_hash; 6152 obj->vertab[vernum].name = obj->strtab + vda->vda_name; 6153 obj->vertab[vernum].file = NULL; 6154 obj->vertab[vernum].flags = 0; 6155 } 6156 if (vd->vd_next == 0) 6157 break; 6158 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 6159 } 6160 6161 vn = obj->verneed; 6162 while (vn != NULL) { 6163 depobj = locate_dependency(obj, obj->strtab + vn->vn_file); 6164 if (depobj == NULL) 6165 return (-1); 6166 vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux); 6167 for (;;) { 6168 if (check_object_provided_version(obj, depobj, vna)) 6169 return (-1); 6170 vernum = VER_NEED_IDX(vna->vna_other); 6171 assert(vernum <= maxvernum); 6172 obj->vertab[vernum].hash = vna->vna_hash; 6173 obj->vertab[vernum].name = obj->strtab + vna->vna_name; 6174 obj->vertab[vernum].file = obj->strtab + vn->vn_file; 6175 obj->vertab[vernum].flags = (vna->vna_other & 6176 VER_NEED_HIDDEN) != 0 ? VER_INFO_HIDDEN : 0; 6177 if (vna->vna_next == 0) 6178 break; 6179 vna = (const Elf_Vernaux *)((const char *)vna + 6180 vna->vna_next); 6181 } 6182 if (vn->vn_next == 0) 6183 break; 6184 vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next); 6185 } 6186 return (0); 6187 } 6188 6189 static int 6190 rtld_verify_versions(const Objlist *objlist) 6191 { 6192 Objlist_Entry *entry; 6193 int rc; 6194 6195 rc = 0; 6196 STAILQ_FOREACH(entry, objlist, link) { 6197 /* 6198 * Skip dummy objects or objects that have their version 6199 * requirements already checked. 6200 */ 6201 if (entry->obj->strtab == NULL || entry->obj->vertab != NULL) 6202 continue; 6203 if (rtld_verify_object_versions(entry->obj) == -1) { 6204 rc = -1; 6205 if (ld_tracing == NULL) 6206 break; 6207 } 6208 } 6209 if (rc == 0 || ld_tracing != NULL) 6210 rc = rtld_verify_object_versions(&obj_rtld); 6211 return (rc); 6212 } 6213 6214 const Ver_Entry * 6215 fetch_ventry(const Obj_Entry *obj, unsigned long symnum) 6216 { 6217 Elf_Versym vernum; 6218 6219 if (obj->vertab) { 6220 vernum = VER_NDX(obj->versyms[symnum]); 6221 if (vernum >= obj->vernum) { 6222 _rtld_error("%s: symbol %s has wrong verneed value %d", 6223 obj->path, obj->strtab + symnum, vernum); 6224 } else if (obj->vertab[vernum].hash != 0) { 6225 return (&obj->vertab[vernum]); 6226 } 6227 } 6228 return (NULL); 6229 } 6230 6231 int 6232 _rtld_get_stack_prot(void) 6233 { 6234 return (stack_prot); 6235 } 6236 6237 int 6238 _rtld_is_dlopened(void *arg) 6239 { 6240 Obj_Entry *obj; 6241 RtldLockState lockstate; 6242 int res; 6243 6244 rlock_acquire(rtld_bind_lock, &lockstate); 6245 obj = dlcheck(arg); 6246 if (obj == NULL) 6247 obj = obj_from_addr(arg); 6248 if (obj == NULL) { 6249 _rtld_error("No shared object contains address"); 6250 lock_release(rtld_bind_lock, &lockstate); 6251 return (-1); 6252 } 6253 res = obj->dlopened ? 1 : 0; 6254 lock_release(rtld_bind_lock, &lockstate); 6255 return (res); 6256 } 6257 6258 static int 6259 obj_remap_relro(Obj_Entry *obj, int prot) 6260 { 6261 const Elf_Phdr *ph; 6262 caddr_t relro_page; 6263 size_t relro_size; 6264 6265 for (ph = obj->phdr; ph < obj->phdr + obj->phnum; ph++) { 6266 if (ph->p_type != PT_GNU_RELRO) 6267 continue; 6268 relro_page = obj->relocbase + rtld_trunc_page(ph->p_vaddr); 6269 relro_size = rtld_round_page(ph->p_vaddr + ph->p_memsz) - 6270 rtld_trunc_page(ph->p_vaddr); 6271 if (mprotect(relro_page, relro_size, prot) == -1) { 6272 _rtld_error( 6273 "%s: Cannot set relro protection to %#x: %s", 6274 obj->path, prot, rtld_strerror(errno)); 6275 return (-1); 6276 } 6277 break; 6278 } 6279 return (0); 6280 } 6281 6282 static int 6283 obj_disable_relro(Obj_Entry *obj) 6284 { 6285 return (obj_remap_relro(obj, PROT_READ | PROT_WRITE)); 6286 } 6287 6288 static int 6289 obj_enforce_relro(Obj_Entry *obj) 6290 { 6291 return (obj_remap_relro(obj, PROT_READ)); 6292 } 6293 6294 static void 6295 map_stacks_exec(RtldLockState *lockstate) 6296 { 6297 void (*thr_map_stacks_exec)(void); 6298 6299 if ((max_stack_flags & PF_X) == 0 || (stack_prot & PROT_EXEC) != 0) 6300 return; 6301 thr_map_stacks_exec = (void (*)(void))( 6302 uintptr_t)get_program_var_addr("__pthread_map_stacks_exec", 6303 lockstate); 6304 if (thr_map_stacks_exec != NULL) { 6305 stack_prot |= PROT_EXEC; 6306 thr_map_stacks_exec(); 6307 } 6308 } 6309 6310 static void 6311 distribute_static_tls(Objlist *list) 6312 { 6313 struct tcb_list_entry *tcbelm; 6314 Objlist_Entry *objelm; 6315 struct tcb *tcb; 6316 Obj_Entry *obj; 6317 char *tlsbase; 6318 6319 STAILQ_FOREACH(objelm, list, link) { 6320 obj = objelm->obj; 6321 if (obj->marker || !obj->tls_static || obj->static_tls_copied) 6322 continue; 6323 TAILQ_FOREACH(tcbelm, &tcb_list, next) { 6324 tcb = tcb_from_tcb_list_entry(tcbelm); 6325 #ifdef TLS_VARIANT_I 6326 tlsbase = (char *)tcb + obj->tlsoffset; 6327 #else 6328 tlsbase = (char *)tcb - obj->tlsoffset; 6329 #endif 6330 memcpy(tlsbase, obj->tlsinit, obj->tlsinitsize); 6331 memset(tlsbase + obj->tlsinitsize, 0, 6332 obj->tlssize - obj->tlsinitsize); 6333 } 6334 obj->static_tls_copied = true; 6335 } 6336 } 6337 6338 void 6339 symlook_init(SymLook *dst, const char *name) 6340 { 6341 bzero(dst, sizeof(*dst)); 6342 dst->name = name; 6343 dst->hash = elf_hash(name); 6344 dst->hash_gnu = gnu_hash(name); 6345 } 6346 6347 static void 6348 symlook_init_from_req(SymLook *dst, const SymLook *src) 6349 { 6350 dst->name = src->name; 6351 dst->hash = src->hash; 6352 dst->hash_gnu = src->hash_gnu; 6353 dst->ventry = src->ventry; 6354 dst->flags = src->flags; 6355 dst->defobj_out = NULL; 6356 dst->sym_out = NULL; 6357 dst->lockstate = src->lockstate; 6358 dst->donelist_mem = NULL; 6359 } 6360 6361 static int 6362 open_binary_fd(const char *argv0, bool search_in_path, const char **binpath_res) 6363 { 6364 char *binpath, *pathenv, *pe, *res1; 6365 const char *res; 6366 int fd; 6367 6368 binpath = NULL; 6369 res = NULL; 6370 if (search_in_path && strchr(argv0, '/') == NULL) { 6371 binpath = xmalloc(PATH_MAX); 6372 pathenv = getenv("PATH"); 6373 if (pathenv == NULL) { 6374 _rtld_error("-p and no PATH environment variable"); 6375 rtld_die(); 6376 } 6377 pathenv = strdup(pathenv); 6378 if (pathenv == NULL) { 6379 _rtld_error("Cannot allocate memory"); 6380 rtld_die(); 6381 } 6382 fd = -1; 6383 errno = ENOENT; 6384 while ((pe = strsep(&pathenv, ":")) != NULL) { 6385 if (strlcpy(binpath, pe, PATH_MAX) >= PATH_MAX) 6386 continue; 6387 if (binpath[0] != '\0' && 6388 strlcat(binpath, "/", PATH_MAX) >= PATH_MAX) 6389 continue; 6390 if (strlcat(binpath, argv0, PATH_MAX) >= PATH_MAX) 6391 continue; 6392 fd = open(binpath, O_RDONLY | O_CLOEXEC | O_VERIFY); 6393 if (fd != -1 || errno != ENOENT) { 6394 res = binpath; 6395 break; 6396 } 6397 } 6398 free(pathenv); 6399 } else { 6400 fd = open(argv0, O_RDONLY | O_CLOEXEC | O_VERIFY); 6401 res = argv0; 6402 } 6403 6404 if (fd == -1) { 6405 _rtld_error("Cannot open %s: %s", argv0, rtld_strerror(errno)); 6406 rtld_die(); 6407 } 6408 if (res != NULL && res[0] != '/') { 6409 res1 = xmalloc(PATH_MAX); 6410 if (realpath(res, res1) != NULL) { 6411 if (res != argv0) 6412 free(__DECONST(char *, res)); 6413 res = res1; 6414 } else { 6415 free(res1); 6416 } 6417 } 6418 *binpath_res = res; 6419 return (fd); 6420 } 6421 6422 /* 6423 * Parse a set of command-line arguments. 6424 */ 6425 static int 6426 parse_args(char *argv[], int argc, bool *use_pathp, int *fdp, 6427 const char **argv0, bool *dir_ignore) 6428 { 6429 const char *arg; 6430 char machine[64]; 6431 size_t sz; 6432 int arglen, fd, i, j, mib[2]; 6433 char opt; 6434 bool seen_b, seen_f; 6435 6436 dbg("Parsing command-line arguments"); 6437 *use_pathp = false; 6438 *fdp = -1; 6439 *dir_ignore = false; 6440 seen_b = seen_f = false; 6441 6442 for (i = 1; i < argc; i++) { 6443 arg = argv[i]; 6444 dbg("argv[%d]: '%s'", i, arg); 6445 6446 /* 6447 * rtld arguments end with an explicit "--" or with the first 6448 * non-prefixed argument. 6449 */ 6450 if (strcmp(arg, "--") == 0) { 6451 i++; 6452 break; 6453 } 6454 if (arg[0] != '-') 6455 break; 6456 6457 /* 6458 * All other arguments are single-character options that can 6459 * be combined, so we need to search through `arg` for them. 6460 */ 6461 arglen = strlen(arg); 6462 for (j = 1; j < arglen; j++) { 6463 opt = arg[j]; 6464 if (opt == 'h') { 6465 print_usage(argv[0]); 6466 _exit(0); 6467 } else if (opt == 'b') { 6468 if (seen_f) { 6469 _rtld_error("Both -b and -f specified"); 6470 rtld_die(); 6471 } 6472 if (j != arglen - 1) { 6473 _rtld_error("Invalid options: %s", arg); 6474 rtld_die(); 6475 } 6476 i++; 6477 *argv0 = argv[i]; 6478 seen_b = true; 6479 break; 6480 } else if (opt == 'd') { 6481 *dir_ignore = true; 6482 } else if (opt == 'f') { 6483 if (seen_b) { 6484 _rtld_error("Both -b and -f specified"); 6485 rtld_die(); 6486 } 6487 6488 /* 6489 * -f XX can be used to specify a 6490 * descriptor for the binary named at 6491 * the command line (i.e., the later 6492 * argument will specify the process 6493 * name but the descriptor is what 6494 * will actually be executed). 6495 * 6496 * -f must be the last option in the 6497 * group, e.g., -abcf <fd>. 6498 */ 6499 if (j != arglen - 1) { 6500 _rtld_error("Invalid options: %s", arg); 6501 rtld_die(); 6502 } 6503 i++; 6504 fd = parse_integer(argv[i]); 6505 if (fd == -1) { 6506 _rtld_error( 6507 "Invalid file descriptor: '%s'", 6508 argv[i]); 6509 rtld_die(); 6510 } 6511 *fdp = fd; 6512 seen_f = true; 6513 break; 6514 } else if (opt == 'o') { 6515 struct ld_env_var_desc *l; 6516 char *n, *v; 6517 u_int ll; 6518 6519 if (j != arglen - 1) { 6520 _rtld_error("Invalid options: %s", arg); 6521 rtld_die(); 6522 } 6523 i++; 6524 n = argv[i]; 6525 v = strchr(n, '='); 6526 if (v == NULL) { 6527 _rtld_error("No '=' in -o parameter"); 6528 rtld_die(); 6529 } 6530 for (ll = 0; ll < nitems(ld_env_vars); ll++) { 6531 l = &ld_env_vars[ll]; 6532 if (v - n == (ptrdiff_t)strlen(l->n) && 6533 strncmp(n, l->n, v - n) == 0) { 6534 l->val = v + 1; 6535 break; 6536 } 6537 } 6538 if (ll == nitems(ld_env_vars)) { 6539 _rtld_error("Unknown LD_ option %s", n); 6540 rtld_die(); 6541 } 6542 } else if (opt == 'p') { 6543 *use_pathp = true; 6544 } else if (opt == 'u') { 6545 u_int ll; 6546 6547 for (ll = 0; ll < nitems(ld_env_vars); ll++) 6548 ld_env_vars[ll].val = NULL; 6549 } else if (opt == 'v') { 6550 machine[0] = '\0'; 6551 mib[0] = CTL_HW; 6552 mib[1] = HW_MACHINE; 6553 sz = sizeof(machine); 6554 sysctl(mib, nitems(mib), machine, &sz, NULL, 0); 6555 ld_elf_hints_path = ld_get_env_var( 6556 LD_ELF_HINTS_PATH); 6557 set_ld_elf_hints_path(); 6558 rtld_printf( 6559 "FreeBSD ld-elf.so.1 %s\n" 6560 "FreeBSD_version %d\n" 6561 "Default lib path %s\n" 6562 "Hints lib path %s\n" 6563 "Env prefix %s\n" 6564 "Default hint file %s\n" 6565 "Hint file %s\n" 6566 "libmap file %s\n" 6567 "Optional static TLS size %zd bytes\n", 6568 machine, __FreeBSD_version, 6569 ld_standard_library_path, gethints(false), 6570 ld_env_prefix, ld_elf_hints_default, 6571 ld_elf_hints_path, ld_path_libmap_conf, 6572 ld_static_tls_extra); 6573 _exit(0); 6574 } else { 6575 _rtld_error("Invalid argument: '%s'", arg); 6576 print_usage(argv[0]); 6577 rtld_die(); 6578 } 6579 } 6580 } 6581 6582 if (!seen_b) 6583 *argv0 = argv[i]; 6584 return (i); 6585 } 6586 6587 /* 6588 * Parse a file descriptor number without pulling in more of libc (e.g. atoi). 6589 */ 6590 static int 6591 parse_integer(const char *str) 6592 { 6593 int radix; 6594 const char *orig; 6595 int n, val; 6596 char c; 6597 6598 if (str[0] == '0') { 6599 if (str[1] == 'x') { 6600 str += 2; 6601 radix = 16; 6602 } else if (str[1] == 'b') { 6603 str += 2; 6604 radix = 2; 6605 } else { 6606 str += 1; 6607 radix = 8; 6608 } 6609 } else { 6610 radix = 10; 6611 } 6612 orig = str; 6613 n = 0; 6614 for (c = *str; c != '\0'; c = *++str) { 6615 if (c >= '0' && c <= '9') 6616 val = c - '0'; 6617 else if (c >= 'a' && c <= 'f') 6618 val = c - 'a' + 10; 6619 else if (c >= 'A' && c <= 'F') 6620 val = c - 'A' + 10; 6621 else 6622 return (-1); 6623 if (val >= radix) 6624 return (-1); 6625 6626 if (n > INT_MAX / radix) 6627 return (-1); 6628 n *= radix; 6629 if (n > INT_MAX - val) 6630 return (-1); 6631 n += val; 6632 } 6633 6634 /* 6635 * Make sure we actually parsed something. 6636 * Allow for lone '0'. 6637 */ 6638 if (str == orig && radix != 8) 6639 return (-1); 6640 return (n); 6641 } 6642 6643 static void 6644 print_usage(const char *argv0) 6645 { 6646 rtld_printf( 6647 "Usage: %s [-h] [-b <exe>] [-d] [-f <FD>] [-p] [--] <binary> [<args>]\n" 6648 "\n" 6649 "Options:\n" 6650 " -h Display this help message\n" 6651 " -b <exe> Execute <exe> instead of <binary>, arg0 is <binary>\n" 6652 " -d Ignore lack of exec permissions for the binary\n" 6653 " -f <FD> Execute <FD> instead of searching for <binary>\n" 6654 " -o <OPT>=<VAL> Set LD_<OPT> to <VAL>, without polluting env\n" 6655 " -p Search in PATH for named binary\n" 6656 " -u Ignore LD_ environment variables\n" 6657 " -v Display identification information\n" 6658 " -- End of RTLD options\n" 6659 " <binary> Name of process to execute\n" 6660 " <args> Arguments to the executed process\n", 6661 argv0); 6662 } 6663 6664 #define AUXFMT(at, xfmt) [at] = { .name = #at, .fmt = xfmt } 6665 static const struct auxfmt { 6666 const char *name; 6667 const char *fmt; 6668 } auxfmts[] = { 6669 AUXFMT(AT_NULL, NULL), 6670 AUXFMT(AT_IGNORE, NULL), 6671 AUXFMT(AT_EXECFD, "%ld"), 6672 AUXFMT(AT_PHDR, "%p"), 6673 AUXFMT(AT_PHENT, "%lu"), 6674 AUXFMT(AT_PHNUM, "%lu"), 6675 AUXFMT(AT_PAGESZ, "%lu"), 6676 AUXFMT(AT_BASE, "%#lx"), 6677 AUXFMT(AT_FLAGS, "%#lx"), 6678 AUXFMT(AT_ENTRY, "%p"), 6679 AUXFMT(AT_NOTELF, NULL), 6680 AUXFMT(AT_UID, "%ld"), 6681 AUXFMT(AT_EUID, "%ld"), 6682 AUXFMT(AT_GID, "%ld"), 6683 AUXFMT(AT_EGID, "%ld"), 6684 AUXFMT(AT_EXECPATH, "%s"), 6685 AUXFMT(AT_CANARY, "%p"), 6686 AUXFMT(AT_CANARYLEN, "%lu"), 6687 AUXFMT(AT_OSRELDATE, "%lu"), 6688 AUXFMT(AT_NCPUS, "%lu"), 6689 AUXFMT(AT_PAGESIZES, "%p"), 6690 AUXFMT(AT_PAGESIZESLEN, "%lu"), 6691 AUXFMT(AT_TIMEKEEP, "%p"), 6692 AUXFMT(AT_STACKPROT, "%#lx"), 6693 AUXFMT(AT_EHDRFLAGS, "%#lx"), 6694 AUXFMT(AT_HWCAP, "%#lx"), 6695 AUXFMT(AT_HWCAP2, "%#lx"), 6696 AUXFMT(AT_BSDFLAGS, "%#lx"), 6697 AUXFMT(AT_ARGC, "%lu"), 6698 AUXFMT(AT_ARGV, "%p"), 6699 AUXFMT(AT_ENVC, "%p"), 6700 AUXFMT(AT_ENVV, "%p"), 6701 AUXFMT(AT_PS_STRINGS, "%p"), 6702 AUXFMT(AT_FXRNG, "%p"), 6703 AUXFMT(AT_KPRELOAD, "%p"), 6704 AUXFMT(AT_USRSTACKBASE, "%#lx"), 6705 AUXFMT(AT_USRSTACKLIM, "%#lx"), 6706 /* AT_CHERI_STATS */ 6707 AUXFMT(AT_HWCAP3, "%#lx"), 6708 AUXFMT(AT_HWCAP4, "%#lx"), 6709 6710 }; 6711 6712 static bool 6713 is_ptr_fmt(const char *fmt) 6714 { 6715 char last; 6716 6717 last = fmt[strlen(fmt) - 1]; 6718 return (last == 'p' || last == 's'); 6719 } 6720 6721 static void 6722 dump_auxv(Elf_Auxinfo **aux_info) 6723 { 6724 Elf_Auxinfo *auxp; 6725 const struct auxfmt *fmt; 6726 int i; 6727 6728 for (i = 0; i < AT_COUNT; i++) { 6729 auxp = aux_info[i]; 6730 if (auxp == NULL) 6731 continue; 6732 fmt = &auxfmts[i]; 6733 if (fmt->fmt == NULL) 6734 continue; 6735 rtld_fdprintf(STDOUT_FILENO, "%s:\t", fmt->name); 6736 if (is_ptr_fmt(fmt->fmt)) { 6737 rtld_fdprintfx(STDOUT_FILENO, fmt->fmt, 6738 auxp->a_un.a_ptr); 6739 } else { 6740 rtld_fdprintfx(STDOUT_FILENO, fmt->fmt, 6741 auxp->a_un.a_val); 6742 } 6743 rtld_fdprintf(STDOUT_FILENO, "\n"); 6744 } 6745 } 6746 6747 const char * 6748 rtld_get_var(const char *name) 6749 { 6750 const struct ld_env_var_desc *lvd; 6751 u_int i; 6752 6753 for (i = 0; i < nitems(ld_env_vars); i++) { 6754 lvd = &ld_env_vars[i]; 6755 if (strcmp(lvd->n, name) == 0) 6756 return (lvd->val); 6757 } 6758 return (NULL); 6759 } 6760 6761 static void 6762 rtld_recalc_dangerous_ld_env(void) 6763 { 6764 /* 6765 * Never reset dangerous_ld_env back to false if rtld was ever 6766 * contaminated with it set to true. 6767 */ 6768 dangerous_ld_env |= libmap_disable || libmap_override != NULL || 6769 ld_library_path != NULL || ld_preload != NULL || 6770 ld_elf_hints_path != NULL || ld_loadfltr || !ld_dynamic_weak || 6771 ld_get_env_var(LD_STATIC_TLS_EXTRA) != NULL; 6772 } 6773 6774 static void 6775 rtld_recalc_debug(const char *ld_debug) 6776 { 6777 if (ld_debug != NULL && *ld_debug != '\0') 6778 debug = 1; 6779 } 6780 6781 static void 6782 rtld_set_var_debug(struct ld_env_var_desc *lvd) 6783 { 6784 rtld_recalc_debug(lvd->val); 6785 } 6786 6787 static void 6788 rtld_set_var_library_path(struct ld_env_var_desc *lvd) 6789 { 6790 ld_library_path = lvd->val; 6791 } 6792 6793 static void 6794 rtld_set_var_library_path_fds(struct ld_env_var_desc *lvd) 6795 { 6796 ld_library_dirs = lvd->val; 6797 } 6798 6799 static void 6800 rtld_recalc_path_rpath(const char *library_path_rpath) 6801 { 6802 if (library_path_rpath != NULL) { 6803 if (library_path_rpath[0] == 'y' || 6804 library_path_rpath[0] == 'Y' || 6805 library_path_rpath[0] == '1') 6806 ld_library_path_rpath = true; 6807 else 6808 ld_library_path_rpath = false; 6809 } else { 6810 ld_library_path_rpath = false; 6811 } 6812 } 6813 6814 static void 6815 rtld_set_var_library_path_rpath(struct ld_env_var_desc *lvd) 6816 { 6817 rtld_recalc_path_rpath(lvd->val); 6818 } 6819 6820 static void 6821 rtld_recalc_bind_not(const char *bind_not_val) 6822 { 6823 if (ld_bind_now == NULL) 6824 ld_bind_not = bind_not_val != NULL; 6825 } 6826 6827 static void 6828 rtld_set_var_bind_now(struct ld_env_var_desc *lvd) 6829 { 6830 ld_bind_now = lvd->val; 6831 rtld_recalc_bind_not(ld_get_env_var(LD_BIND_NOT)); 6832 } 6833 6834 static void 6835 rtld_set_var_bind_not(struct ld_env_var_desc *lvd) 6836 { 6837 rtld_recalc_bind_not(lvd->val); 6838 } 6839 6840 static void 6841 rtld_set_var_dynamic_weak(struct ld_env_var_desc *lvd) 6842 { 6843 ld_dynamic_weak = lvd->val == NULL; 6844 } 6845 6846 static void 6847 rtld_set_var_loadfltr(struct ld_env_var_desc *lvd) 6848 { 6849 ld_loadfltr = lvd->val != NULL; 6850 } 6851 6852 static void 6853 rtld_set_var_libmap_disable(struct ld_env_var_desc *lvd) 6854 { 6855 libmap_disable = lvd->val != NULL; 6856 } 6857 6858 int 6859 rtld_set_var(const char *name, const char *val) 6860 { 6861 RtldLockState lockstate; 6862 struct ld_env_var_desc *lvd; 6863 u_int i; 6864 int error; 6865 6866 error = ENOENT; 6867 wlock_acquire(rtld_bind_lock, &lockstate); 6868 for (i = 0; i < nitems(ld_env_vars); i++) { 6869 lvd = &ld_env_vars[i]; 6870 if (strcmp(lvd->n, name) != 0) 6871 continue; 6872 if (!lvd->can_update || (lvd->unsecure && !trust)) { 6873 error = EPERM; 6874 break; 6875 } 6876 if (lvd->owned) 6877 free(__DECONST(char *, lvd->val)); 6878 if (val != NULL) 6879 lvd->val = xstrdup(val); 6880 else 6881 lvd->val = NULL; 6882 lvd->owned = true; 6883 if (lvd->on_update != NULL) 6884 lvd->on_update(lvd); 6885 error = 0; 6886 break; 6887 } 6888 if (error == 0) 6889 rtld_recalc_dangerous_ld_env(); 6890 lock_release(rtld_bind_lock, &lockstate); 6891 return (error); 6892 } 6893 6894 /* 6895 * Overrides for libc_pic-provided functions. 6896 */ 6897 6898 int 6899 __getosreldate(void) 6900 { 6901 size_t len; 6902 int oid[2]; 6903 int error, osrel; 6904 6905 if (osreldate != 0) 6906 return (osreldate); 6907 6908 oid[0] = CTL_KERN; 6909 oid[1] = KERN_OSRELDATE; 6910 osrel = 0; 6911 len = sizeof(osrel); 6912 error = sysctl(oid, 2, &osrel, &len, NULL, 0); 6913 if (error == 0 && osrel > 0 && len == sizeof(osrel)) 6914 osreldate = osrel; 6915 return (osreldate); 6916 } 6917 const char * 6918 rtld_strerror(int errnum) 6919 { 6920 if (errnum < 0 || errnum >= sys_nerr) 6921 return ("Unknown error"); 6922 return (sys_errlist[errnum]); 6923 } 6924 6925 char * 6926 getenv(const char *name) 6927 { 6928 return (__DECONST(char *, rtld_get_env_val(environ, name, 6929 strlen(name)))); 6930 } 6931 6932 extern int _rtld_version__FreeBSD_version __exported; 6933 int _rtld_version__FreeBSD_version = __FreeBSD_version; 6934 6935 extern char _rtld_version_laddr_offset __exported; 6936 char _rtld_version_laddr_offset; 6937 6938 extern char _rtld_version_dlpi_tls_data __exported; 6939 char _rtld_version_dlpi_tls_data; 6940