1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright 1996, 1997, 1998, 1999, 2000 John D. Polstra. 5 * Copyright 2003 Alexander Kabaev <kan@FreeBSD.ORG>. 6 * Copyright 2009-2013 Konstantin Belousov <kib@FreeBSD.ORG>. 7 * Copyright 2012 John Marino <draco@marino.st>. 8 * Copyright 2014-2017 The FreeBSD Foundation 9 * All rights reserved. 10 * 11 * Portions of this software were developed by Konstantin Belousov 12 * under sponsorship from the FreeBSD Foundation. 13 * 14 * Redistribution and use in source and binary forms, with or without 15 * modification, are permitted provided that the following conditions 16 * are met: 17 * 1. Redistributions of source code must retain the above copyright 18 * notice, this list of conditions and the following disclaimer. 19 * 2. Redistributions in binary form must reproduce the above copyright 20 * notice, this list of conditions and the following disclaimer in the 21 * documentation and/or other materials provided with the distribution. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 24 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 25 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 26 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 27 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 28 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 29 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 30 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 31 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 32 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 33 */ 34 35 /* 36 * Dynamic linker for ELF. 37 * 38 * John Polstra <jdp@polstra.com>. 39 */ 40 41 #include <sys/param.h> 42 #include <sys/ktrace.h> 43 #include <sys/mman.h> 44 #include <sys/mount.h> 45 #include <sys/stat.h> 46 #include <sys/sysctl.h> 47 #include <sys/uio.h> 48 #include <sys/utsname.h> 49 50 #include <dlfcn.h> 51 #include <err.h> 52 #include <errno.h> 53 #include <fcntl.h> 54 #include <stdarg.h> 55 #include <stdio.h> 56 #include <stdlib.h> 57 #include <string.h> 58 #include <unistd.h> 59 60 #include "debug.h" 61 #include "libmap.h" 62 #include "notes.h" 63 #include "rtld.h" 64 #include "rtld_libc.h" 65 #include "rtld_malloc.h" 66 #include "rtld_paths.h" 67 #include "rtld_printf.h" 68 #include "rtld_tls.h" 69 #include "rtld_utrace.h" 70 71 /* Types. */ 72 typedef void (*func_ptr_type)(void); 73 typedef void *(*path_enum_proc)(const char *path, size_t len, void *arg); 74 75 /* Variables that cannot be static: */ 76 extern struct r_debug r_debug; /* For GDB */ 77 extern int _thread_autoinit_dummy_decl; 78 extern void (*__cleanup)(void); 79 80 struct dlerror_save { 81 int seen; 82 char *msg; 83 }; 84 85 struct tcb_list_entry { 86 TAILQ_ENTRY(tcb_list_entry) next; 87 }; 88 89 /* 90 * Function declarations. 91 */ 92 static bool allocate_tls_offset_common(size_t *offp, size_t tlssize, 93 size_t tlsalign, size_t tlspoffset); 94 static const char *basename(const char *); 95 static void digest_dynamic1(Obj_Entry *, int, const Elf_Dyn **, 96 const Elf_Dyn **, const Elf_Dyn **); 97 static bool digest_dynamic2(Obj_Entry *, const Elf_Dyn *, const Elf_Dyn *, 98 const Elf_Dyn *); 99 static bool digest_dynamic(Obj_Entry *, int); 100 static Obj_Entry *digest_phdr(const Elf_Phdr *, int, caddr_t, const char *); 101 static void distribute_static_tls(Objlist *); 102 static Obj_Entry *dlcheck(void *); 103 static int dlclose_locked(void *, RtldLockState *); 104 static Obj_Entry *dlopen_object(const char *name, int fd, Obj_Entry *refobj, 105 int lo_flags, int mode, RtldLockState *lockstate); 106 static Obj_Entry *do_load_object(int, const char *, char *, struct stat *, int); 107 static int do_search_info(const Obj_Entry *obj, int, struct dl_serinfo *); 108 static bool donelist_check(DoneList *, const Obj_Entry *); 109 static void dump_auxv(Elf_Auxinfo **aux_info); 110 static void errmsg_restore(struct dlerror_save *); 111 static struct dlerror_save *errmsg_save(void); 112 static void *fill_search_info(const char *, size_t, void *); 113 static char *find_library(const char *, const Obj_Entry *, int *); 114 static const char *gethints(bool); 115 static void hold_object(Obj_Entry *); 116 static void unhold_object(Obj_Entry *); 117 static void init_dag(Obj_Entry *); 118 static void init_marker(Obj_Entry *); 119 static void init_pagesizes(Elf_Auxinfo **aux_info); 120 static void init_rtld(caddr_t, Elf_Auxinfo **); 121 static void initlist_add_neededs(Needed_Entry *, Objlist *, Objlist *); 122 static void initlist_add_objects(Obj_Entry *, Obj_Entry *, Objlist *, 123 Objlist *); 124 static void initlist_for_loaded_obj(Obj_Entry *obj, Obj_Entry *tail, 125 Objlist *list); 126 static int initlist_objects_ifunc(Objlist *, bool, int, RtldLockState *); 127 static void linkmap_add(Obj_Entry *); 128 static void linkmap_delete(Obj_Entry *); 129 static void load_filtees(Obj_Entry *, int flags, RtldLockState *); 130 static void unload_filtees(Obj_Entry *, RtldLockState *); 131 static int load_needed_objects(Obj_Entry *, int); 132 static int load_preload_objects(const char *, bool); 133 static int load_kpreload(const void *addr); 134 static Obj_Entry *load_object(const char *, int fd, const Obj_Entry *, int); 135 static void map_stacks_exec(RtldLockState *); 136 static int obj_disable_relro(Obj_Entry *); 137 static int obj_enforce_relro(Obj_Entry *); 138 static void objlist_call_fini(Objlist *, Obj_Entry *, RtldLockState *); 139 static void objlist_call_init(Objlist *, RtldLockState *); 140 static void objlist_clear(Objlist *); 141 static Objlist_Entry *objlist_find(Objlist *, const Obj_Entry *); 142 static void objlist_init(Objlist *); 143 static void objlist_push_head(Objlist *, Obj_Entry *); 144 static void objlist_push_tail(Objlist *, Obj_Entry *); 145 static void objlist_put_after(Objlist *, Obj_Entry *, Obj_Entry *); 146 static void objlist_remove(Objlist *, Obj_Entry *); 147 static int open_binary_fd(const char *argv0, bool search_in_path, 148 const char **binpath_res); 149 static int parse_args(char *argv[], int argc, bool *use_pathp, int *fdp, 150 const char **argv0, bool *dir_ignore); 151 static int parse_integer(const char *); 152 static void *path_enumerate(const char *, path_enum_proc, const char *, void *); 153 static void print_usage(const char *argv0); 154 static void release_object(Obj_Entry *); 155 static int relocate_object_dag(Obj_Entry *root, bool bind_now, 156 Obj_Entry *rtldobj, int flags, RtldLockState *lockstate); 157 static int relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, 158 int flags, RtldLockState *lockstate); 159 static int relocate_objects(Obj_Entry *, bool, Obj_Entry *, int, 160 RtldLockState *); 161 static int resolve_object_ifunc(Obj_Entry *, bool, int, RtldLockState *); 162 static int rtld_dirname(const char *, char *); 163 static int rtld_dirname_abs(const char *, char *); 164 static void *rtld_dlopen(const char *name, int fd, int mode); 165 static void rtld_exit(void); 166 static void rtld_nop_exit(void); 167 static char *search_library_path(const char *, const char *, const char *, 168 int *); 169 static char *search_library_pathfds(const char *, const char *, int *); 170 static const void **get_program_var_addr(const char *, RtldLockState *); 171 static void set_program_var(const char *, const void *); 172 static int symlook_default(SymLook *, const Obj_Entry *refobj); 173 static int symlook_global(SymLook *, DoneList *); 174 static void symlook_init_from_req(SymLook *, const SymLook *); 175 static int symlook_list(SymLook *, const Objlist *, DoneList *); 176 static int symlook_needed(SymLook *, const Needed_Entry *, DoneList *); 177 static int symlook_obj1_sysv(SymLook *, const Obj_Entry *); 178 static int symlook_obj1_gnu(SymLook *, const Obj_Entry *); 179 static void *tls_get_addr_slow(struct tcb *, int, size_t, bool) __noinline; 180 static void trace_loaded_objects(Obj_Entry *, bool); 181 static int try_fds_open(const char *name, const char *path); 182 static void unlink_object(Obj_Entry *); 183 static void unload_object(Obj_Entry *, RtldLockState *lockstate); 184 static void unref_dag(Obj_Entry *); 185 static void ref_dag(Obj_Entry *); 186 static char *origin_subst_one(Obj_Entry *, char *, const char *, const char *, 187 bool); 188 static char *origin_subst(Obj_Entry *, const char *); 189 static bool obj_resolve_origin(Obj_Entry *obj); 190 static void preinit_main(void); 191 static void rtld_recalc_bind_not(const char *); 192 static void rtld_recalc_dangerous_ld_env(void); 193 static void rtld_recalc_debug(const char *); 194 static void rtld_recalc_path_rpath(const char *); 195 static int rtld_verify_versions(const Objlist *); 196 static int rtld_verify_object_versions(Obj_Entry *); 197 static void object_add_name(Obj_Entry *, const char *); 198 static int object_match_name(const Obj_Entry *, const char *); 199 static void ld_utrace_log(int, void *, void *, size_t, int, const char *); 200 static void rtld_fill_dl_phdr_info(const Obj_Entry *obj, 201 struct dl_phdr_info *phdr_info); 202 static uint32_t gnu_hash(const char *); 203 static bool matched_symbol(SymLook *, const Obj_Entry *, Sym_Match_Result *, 204 const unsigned long); 205 206 struct ld_env_var_desc; 207 static void rtld_set_var_bind_not(struct ld_env_var_desc *lvd); 208 static void rtld_set_var_bind_now(struct ld_env_var_desc *lvd); 209 static void rtld_set_var_debug(struct ld_env_var_desc *lvd); 210 static void rtld_set_var_dynamic_weak(struct ld_env_var_desc *lvd); 211 static void rtld_set_var_libmap_disable(struct ld_env_var_desc *lvd); 212 static void rtld_set_var_library_path(struct ld_env_var_desc *lvd); 213 static void rtld_set_var_library_path_fds(struct ld_env_var_desc *lvd); 214 static void rtld_set_var_library_path_rpath(struct ld_env_var_desc *lvd); 215 static void rtld_set_var_loadfltr(struct ld_env_var_desc *lvd); 216 217 void r_debug_state(struct r_debug *, struct link_map *) __noinline __exported; 218 void _r_debug_postinit(struct link_map *) __noinline __exported; 219 220 int __sys_openat(int, const char *, int, ...); 221 222 /* 223 * Data declarations. 224 */ 225 struct r_debug r_debug __exported; /* for GDB; */ 226 static bool libmap_disable; /* Disable libmap */ 227 static bool ld_loadfltr; /* Immediate filters processing */ 228 static const char *libmap_override; /* Maps to use in addition to libmap.conf */ 229 static bool trust; /* False for setuid and setgid programs */ 230 static bool dangerous_ld_env; /* True if environment variables have been 231 used to affect the libraries loaded */ 232 bool ld_bind_not; /* Disable PLT update */ 233 static const char *ld_bind_now; /* Environment variable for immediate binding */ 234 static bool ld_dynamic_weak = true; /* True if non-weak definition overrides 235 weak definition */ 236 static const char *ld_library_path; /* Environment variable for search path */ 237 static const char 238 *ld_library_dirs; /* Environment variable for library descriptors */ 239 static const char *ld_preload; /* Environment variable for libraries to 240 load first */ 241 static const char *ld_preload_fds; /* Environment variable for libraries 242 represented by descriptors */ 243 static const char 244 *ld_elf_hints_path; /* Environment variable for alternative hints path */ 245 static const char *ld_tracing; /* Called from ldd to print libs */ 246 static const char *ld_utrace; /* Use utrace() to log events. */ 247 static struct obj_entry_q obj_list; /* Queue of all loaded objects */ 248 static Obj_Entry *obj_main; /* The main program shared object */ 249 static Obj_Entry obj_rtld; /* The dynamic linker shared object */ 250 static unsigned int obj_count; /* Number of objects in obj_list */ 251 static unsigned int obj_loads; /* Number of loads of objects (gen count) */ 252 size_t ld_static_tls_extra = /* Static TLS extra space (bytes) */ 253 RTLD_STATIC_TLS_EXTRA; 254 255 static Objlist list_global = /* Objects dlopened with RTLD_GLOBAL */ 256 STAILQ_HEAD_INITIALIZER(list_global); 257 static Objlist list_main = /* Objects loaded at program startup */ 258 STAILQ_HEAD_INITIALIZER(list_main); 259 static Objlist list_fini = /* Objects needing fini() calls */ 260 STAILQ_HEAD_INITIALIZER(list_fini); 261 262 Elf_Sym sym_zero; /* For resolving undefined weak refs. */ 263 264 #define GDB_STATE(s, m) \ 265 r_debug.r_state = s; \ 266 r_debug_state(&r_debug, m); 267 268 extern Elf_Dyn _DYNAMIC; 269 #pragma weak _DYNAMIC 270 271 int dlclose(void *) __exported; 272 char *dlerror(void) __exported; 273 void *dlopen(const char *, int) __exported; 274 void *fdlopen(int, int) __exported; 275 void *dlsym(void *, const char *) __exported; 276 dlfunc_t dlfunc(void *, const char *) __exported; 277 void *dlvsym(void *, const char *, const char *) __exported; 278 int dladdr(const void *, Dl_info *) __exported; 279 void dllockinit(void *, void *(*)(void *), void (*)(void *), void (*)(void *), 280 void (*)(void *), void (*)(void *), void (*)(void *)) __exported; 281 int dlinfo(void *, int, void *) __exported; 282 int _dl_iterate_phdr_locked(__dl_iterate_hdr_callback, void *) __exported; 283 int dl_iterate_phdr(__dl_iterate_hdr_callback, void *) __exported; 284 int _rtld_addr_phdr(const void *, struct dl_phdr_info *) __exported; 285 int _rtld_get_stack_prot(void) __exported; 286 int _rtld_is_dlopened(void *) __exported; 287 void _rtld_error(const char *, ...) __exported; 288 const char *rtld_get_var(const char *name) __exported; 289 int rtld_set_var(const char *name, const char *val) __exported; 290 291 /* Only here to fix -Wmissing-prototypes warnings */ 292 int __getosreldate(void); 293 func_ptr_type _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp); 294 Elf_Addr _rtld_bind(Obj_Entry *obj, Elf_Size reloff); 295 296 int npagesizes; 297 static int osreldate; 298 size_t *pagesizes; 299 size_t page_size; 300 301 static int stack_prot = PROT_READ | PROT_WRITE | PROT_EXEC; 302 static int max_stack_flags; 303 304 /* 305 * Global declarations normally provided by crt1. The dynamic linker is 306 * not built with crt1, so we have to provide them ourselves. 307 */ 308 char *__progname; 309 char **environ; 310 311 /* 312 * Used to pass argc, argv to init functions. 313 */ 314 int main_argc; 315 char **main_argv; 316 317 /* 318 * Globals to control TLS allocation. 319 */ 320 size_t tls_last_offset; /* Static TLS offset of last module */ 321 size_t tls_last_size; /* Static TLS size of last module */ 322 size_t tls_static_space; /* Static TLS space allocated */ 323 static size_t tls_static_max_align; 324 Elf_Addr tls_dtv_generation = 1; /* Used to detect when dtv size changes */ 325 int tls_max_index = 1; /* Largest module index allocated */ 326 327 static TAILQ_HEAD(, tcb_list_entry) tcb_list = 328 TAILQ_HEAD_INITIALIZER(tcb_list); 329 static size_t tcb_list_entry_offset; 330 331 static bool ld_library_path_rpath = false; 332 bool ld_fast_sigblock = false; 333 334 /* 335 * Globals for path names, and such 336 */ 337 const char *ld_elf_hints_default = _PATH_ELF_HINTS; 338 const char *ld_path_libmap_conf = _PATH_LIBMAP_CONF; 339 const char *ld_path_rtld = _PATH_RTLD; 340 const char *ld_standard_library_path = STANDARD_LIBRARY_PATH; 341 const char *ld_env_prefix = LD_; 342 343 static void (*rtld_exit_ptr)(void); 344 345 #define LD_UTRACE(e, h, mb, ms, r, n) \ 346 do { \ 347 if (ld_utrace != NULL) \ 348 ld_utrace_log(e, h, mb, ms, r, n); \ 349 } while (0) 350 351 static void 352 ld_utrace_log(int event, void *handle, void *mapbase, size_t mapsize, 353 int refcnt, const char *name) 354 { 355 struct utrace_rtld ut; 356 static const char rtld_utrace_sig[RTLD_UTRACE_SIG_SZ] __nonstring = 357 RTLD_UTRACE_SIG; 358 359 memset(&ut, 0, sizeof(ut)); /* clear holes */ 360 memcpy(ut.sig, rtld_utrace_sig, sizeof(ut.sig)); 361 ut.event = event; 362 ut.handle = handle; 363 ut.mapbase = mapbase; 364 ut.mapsize = mapsize; 365 ut.refcnt = refcnt; 366 if (name != NULL) 367 strlcpy(ut.name, name, sizeof(ut.name)); 368 utrace(&ut, sizeof(ut)); 369 } 370 371 struct ld_env_var_desc { 372 const char *const n; 373 const char *val; 374 const bool unsecure : 1; 375 const bool can_update : 1; 376 bool owned : 1; 377 void (*const on_update)(struct ld_env_var_desc *); 378 }; 379 #define LD_ENV_DESC(var, unsec, ...) \ 380 [LD_##var] = { .n = #var, .unsecure = unsec, __VA_ARGS__ } 381 382 static struct ld_env_var_desc ld_env_vars[] = { 383 LD_ENV_DESC(BIND_NOW, false, .can_update = true, 384 .on_update = rtld_set_var_bind_now), 385 LD_ENV_DESC(PRELOAD, true), 386 LD_ENV_DESC(LIBMAP, true), 387 LD_ENV_DESC(LIBRARY_PATH, true, .can_update = true, 388 .on_update = rtld_set_var_library_path), 389 LD_ENV_DESC(LIBRARY_PATH_FDS, true, .can_update = true, 390 .on_update = rtld_set_var_library_path_fds), 391 LD_ENV_DESC(LIBMAP_DISABLE, true, .can_update = true, 392 .on_update = rtld_set_var_libmap_disable), 393 LD_ENV_DESC(BIND_NOT, true, .can_update = true, 394 .on_update = rtld_set_var_bind_not), 395 LD_ENV_DESC(DEBUG, true, .can_update = true, 396 .on_update = rtld_set_var_debug), 397 LD_ENV_DESC(ELF_HINTS_PATH, true), 398 LD_ENV_DESC(LOADFLTR, true, .can_update = true, 399 .on_update = rtld_set_var_loadfltr), 400 LD_ENV_DESC(LIBRARY_PATH_RPATH, true, .can_update = true, 401 .on_update = rtld_set_var_library_path_rpath), 402 LD_ENV_DESC(PRELOAD_FDS, true), 403 LD_ENV_DESC(DYNAMIC_WEAK, true, .can_update = true, 404 .on_update = rtld_set_var_dynamic_weak), 405 LD_ENV_DESC(TRACE_LOADED_OBJECTS, false), 406 LD_ENV_DESC(UTRACE, false, .can_update = true), 407 LD_ENV_DESC(DUMP_REL_PRE, false, .can_update = true), 408 LD_ENV_DESC(DUMP_REL_POST, false, .can_update = true), 409 LD_ENV_DESC(TRACE_LOADED_OBJECTS_PROGNAME, false), 410 LD_ENV_DESC(TRACE_LOADED_OBJECTS_FMT1, false), 411 LD_ENV_DESC(TRACE_LOADED_OBJECTS_FMT2, false), 412 LD_ENV_DESC(TRACE_LOADED_OBJECTS_ALL, false), 413 LD_ENV_DESC(SHOW_AUXV, true), 414 LD_ENV_DESC(STATIC_TLS_EXTRA, false), 415 LD_ENV_DESC(NO_DL_ITERATE_PHDR_AFTER_FORK, false), 416 }; 417 418 const char * 419 ld_get_env_var(int idx) 420 { 421 return (ld_env_vars[idx].val); 422 } 423 424 static const char * 425 rtld_get_env_val(char **env, const char *name, size_t name_len) 426 { 427 char **m, *n, *v; 428 429 for (m = env; *m != NULL; m++) { 430 n = *m; 431 v = strchr(n, '='); 432 if (v == NULL) { 433 /* corrupt environment? */ 434 continue; 435 } 436 if (v - n == (ptrdiff_t)name_len && 437 strncmp(name, n, name_len) == 0) 438 return (v + 1); 439 } 440 return (NULL); 441 } 442 443 static void 444 rtld_init_env_vars_for_prefix(char **env, const char *env_prefix) 445 { 446 struct ld_env_var_desc *lvd; 447 size_t prefix_len, nlen; 448 char **m, *n, *v; 449 int i; 450 451 prefix_len = strlen(env_prefix); 452 for (m = env; *m != NULL; m++) { 453 n = *m; 454 if (strncmp(env_prefix, n, prefix_len) != 0) { 455 /* Not a rtld environment variable. */ 456 continue; 457 } 458 n += prefix_len; 459 v = strchr(n, '='); 460 if (v == NULL) { 461 /* corrupt environment? */ 462 continue; 463 } 464 for (i = 0; i < (int)nitems(ld_env_vars); i++) { 465 lvd = &ld_env_vars[i]; 466 if (lvd->val != NULL) { 467 /* Saw higher-priority variable name already. */ 468 continue; 469 } 470 nlen = strlen(lvd->n); 471 if (v - n == (ptrdiff_t)nlen && 472 strncmp(lvd->n, n, nlen) == 0) { 473 lvd->val = v + 1; 474 break; 475 } 476 } 477 } 478 } 479 480 static void 481 rtld_init_env_vars(char **env) 482 { 483 rtld_init_env_vars_for_prefix(env, ld_env_prefix); 484 } 485 486 static void 487 set_ld_elf_hints_path(void) 488 { 489 if (ld_elf_hints_path == NULL || strlen(ld_elf_hints_path) == 0) 490 ld_elf_hints_path = ld_elf_hints_default; 491 } 492 493 uintptr_t 494 rtld_round_page(uintptr_t x) 495 { 496 return (roundup2(x, page_size)); 497 } 498 499 uintptr_t 500 rtld_trunc_page(uintptr_t x) 501 { 502 return (rounddown2(x, page_size)); 503 } 504 505 /* 506 * Main entry point for dynamic linking. The first argument is the 507 * stack pointer. The stack is expected to be laid out as described 508 * in the SVR4 ABI specification, Intel 386 Processor Supplement. 509 * Specifically, the stack pointer points to a word containing 510 * ARGC. Following that in the stack is a null-terminated sequence 511 * of pointers to argument strings. Then comes a null-terminated 512 * sequence of pointers to environment strings. Finally, there is a 513 * sequence of "auxiliary vector" entries. 514 * 515 * The second argument points to a place to store the dynamic linker's 516 * exit procedure pointer and the third to a place to store the main 517 * program's object. 518 * 519 * The return value is the main program's entry point. 520 */ 521 func_ptr_type 522 _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp) 523 { 524 Elf_Auxinfo *aux, *auxp, *auxpf, *aux_info[AT_COUNT], auxtmp; 525 Objlist_Entry *entry; 526 Obj_Entry *last_interposer, *obj, *preload_tail; 527 const Elf_Phdr *phdr; 528 Objlist initlist; 529 RtldLockState lockstate; 530 struct stat st; 531 Elf_Addr *argcp; 532 char **argv, **env, **envp, *kexecpath; 533 const char *argv0, *binpath, *static_tls_extra; 534 struct ld_env_var_desc *lvd; 535 caddr_t imgentry; 536 char buf[MAXPATHLEN]; 537 int argc, fd, i, mib[4], old_osrel, osrel, phnum, rtld_argc; 538 size_t sz; 539 bool dir_enable, dir_ignore, direct_exec, explicit_fd, search_in_path; 540 541 /* 542 * On entry, the dynamic linker itself has not been relocated yet. 543 * Be very careful not to reference any global data until after 544 * init_rtld has returned. It is OK to reference file-scope statics 545 * and string constants, and to call static and global functions. 546 */ 547 548 /* Find the auxiliary vector on the stack. */ 549 argcp = sp; 550 argc = *sp++; 551 argv = (char **)sp; 552 sp += argc + 1; /* Skip over arguments and NULL terminator */ 553 env = (char **)sp; 554 while (*sp++ != 0) /* Skip over environment, and NULL terminator */ 555 ; 556 aux = (Elf_Auxinfo *)sp; 557 558 /* Digest the auxiliary vector. */ 559 for (i = 0; i < AT_COUNT; i++) 560 aux_info[i] = NULL; 561 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) { 562 if (auxp->a_type < AT_COUNT) 563 aux_info[auxp->a_type] = auxp; 564 } 565 arch_fix_auxv(aux, aux_info); 566 567 /* Initialize and relocate ourselves. */ 568 assert(aux_info[AT_BASE] != NULL); 569 init_rtld((caddr_t)aux_info[AT_BASE]->a_un.a_ptr, aux_info); 570 571 dlerror_dflt_init(); 572 573 __progname = obj_rtld.path; 574 argv0 = argv[0] != NULL ? argv[0] : "(null)"; 575 environ = env; 576 main_argc = argc; 577 main_argv = argv; 578 579 if (aux_info[AT_BSDFLAGS] != NULL && 580 (aux_info[AT_BSDFLAGS]->a_un.a_val & ELF_BSDF_SIGFASTBLK) != 0) 581 ld_fast_sigblock = true; 582 583 trust = !issetugid(); 584 direct_exec = false; 585 586 md_abi_variant_hook(aux_info); 587 rtld_init_env_vars(env); 588 589 fd = -1; 590 if (aux_info[AT_EXECFD] != NULL) { 591 fd = aux_info[AT_EXECFD]->a_un.a_val; 592 } else { 593 assert(aux_info[AT_PHDR] != NULL); 594 phdr = (const Elf_Phdr *)aux_info[AT_PHDR]->a_un.a_ptr; 595 if (phdr == obj_rtld.phdr) { 596 if (!trust) { 597 _rtld_error( 598 "Tainted process refusing to run binary %s", 599 argv0); 600 rtld_die(); 601 } 602 direct_exec = true; 603 604 dbg("opening main program in direct exec mode"); 605 if (argc >= 2) { 606 rtld_argc = parse_args(argv, argc, 607 &search_in_path, &fd, &argv0, &dir_ignore); 608 explicit_fd = (fd != -1); 609 binpath = NULL; 610 if (!explicit_fd) 611 fd = open_binary_fd(argv0, 612 search_in_path, &binpath); 613 if (fstat(fd, &st) == -1) { 614 _rtld_error( 615 "Failed to fstat FD %d (%s): %s", 616 fd, 617 explicit_fd ? 618 "user-provided descriptor" : 619 argv0, 620 rtld_strerror(errno)); 621 rtld_die(); 622 } 623 624 /* 625 * Rough emulation of the permission checks done 626 * by execve(2), only Unix DACs are checked, 627 * ACLs are ignored. Preserve the semantic of 628 * disabling owner to execute if owner x bit is 629 * cleared, even if others x bit is enabled. 630 * mmap(2) does not allow to mmap with PROT_EXEC 631 * if binary' file comes from noexec mount. We 632 * cannot set a text reference on the binary. 633 */ 634 dir_enable = false; 635 if (st.st_uid == geteuid()) { 636 if ((st.st_mode & S_IXUSR) != 0) 637 dir_enable = true; 638 } else if (st.st_gid == getegid()) { 639 if ((st.st_mode & S_IXGRP) != 0) 640 dir_enable = true; 641 } else if ((st.st_mode & S_IXOTH) != 0) { 642 dir_enable = true; 643 } 644 if (!dir_enable && !dir_ignore) { 645 _rtld_error( 646 "No execute permission for binary %s", 647 argv0); 648 rtld_die(); 649 } 650 651 /* 652 * For direct exec mode, argv[0] is the 653 * interpreter name, we must remove it and shift 654 * arguments left before invoking binary main. 655 * Since stack layout places environment 656 * pointers and aux vectors right after the 657 * terminating NULL, we must shift environment 658 * and aux as well. 659 */ 660 main_argc = argc - rtld_argc; 661 for (i = 0; i <= main_argc; i++) 662 argv[i] = argv[i + rtld_argc]; 663 *argcp -= rtld_argc; 664 environ = env = envp = argv + main_argc + 1; 665 dbg("move env from %p to %p", envp + rtld_argc, 666 envp); 667 do { 668 *envp = *(envp + rtld_argc); 669 } while (*envp++ != NULL); 670 aux = auxp = (Elf_Auxinfo *)envp; 671 auxpf = (Elf_Auxinfo *)(envp + rtld_argc); 672 dbg("move aux from %p to %p", auxpf, aux); 673 /* 674 * XXXKIB insert place for AT_EXECPATH if not 675 * present 676 */ 677 for (;; auxp++, auxpf++) { 678 /* 679 * NB: Use a temporary since *auxpf and 680 * *auxp overlap if rtld_argc is 1 681 */ 682 auxtmp = *auxpf; 683 *auxp = auxtmp; 684 if (auxp->a_type == AT_NULL) 685 break; 686 } 687 /* 688 * Since the auxiliary vector has moved, 689 * redigest it. 690 */ 691 for (i = 0; i < AT_COUNT; i++) 692 aux_info[i] = NULL; 693 for (auxp = aux; auxp->a_type != AT_NULL; 694 auxp++) { 695 if (auxp->a_type < AT_COUNT) 696 aux_info[auxp->a_type] = auxp; 697 } 698 699 /* 700 * Point AT_EXECPATH auxv and aux_info to the 701 * binary path. 702 */ 703 if (binpath == NULL) { 704 aux_info[AT_EXECPATH] = NULL; 705 } else { 706 if (aux_info[AT_EXECPATH] == NULL) { 707 aux_info[AT_EXECPATH] = xmalloc( 708 sizeof(Elf_Auxinfo)); 709 aux_info[AT_EXECPATH]->a_type = 710 AT_EXECPATH; 711 } 712 aux_info[AT_EXECPATH]->a_un.a_ptr = 713 __DECONST(void *, binpath); 714 } 715 } else { 716 _rtld_error("No binary"); 717 rtld_die(); 718 } 719 } 720 } 721 722 ld_bind_now = ld_get_env_var(LD_BIND_NOW); 723 724 /* 725 * If the process is tainted, then we un-set the dangerous environment 726 * variables. The process will be marked as tainted until setuid(2) 727 * is called. If any child process calls setuid(2) we do not want any 728 * future processes to honor the potentially un-safe variables. 729 */ 730 if (!trust) { 731 for (i = 0; i < (int)nitems(ld_env_vars); i++) { 732 lvd = &ld_env_vars[i]; 733 if (lvd->unsecure) 734 lvd->val = NULL; 735 } 736 } 737 738 rtld_recalc_debug(ld_get_env_var(LD_DEBUG)); 739 rtld_recalc_bind_not(ld_get_env_var(LD_BIND_NOT)); 740 ld_dynamic_weak = ld_get_env_var(LD_DYNAMIC_WEAK) == NULL; 741 libmap_disable = ld_get_env_var(LD_LIBMAP_DISABLE) != NULL; 742 libmap_override = ld_get_env_var(LD_LIBMAP); 743 ld_library_path = ld_get_env_var(LD_LIBRARY_PATH); 744 ld_library_dirs = ld_get_env_var(LD_LIBRARY_PATH_FDS); 745 ld_preload = ld_get_env_var(LD_PRELOAD); 746 ld_preload_fds = ld_get_env_var(LD_PRELOAD_FDS); 747 ld_elf_hints_path = ld_get_env_var(LD_ELF_HINTS_PATH); 748 ld_loadfltr = ld_get_env_var(LD_LOADFLTR) != NULL; 749 rtld_recalc_path_rpath(ld_get_env_var(LD_LIBRARY_PATH_RPATH)); 750 static_tls_extra = ld_get_env_var(LD_STATIC_TLS_EXTRA); 751 if (static_tls_extra != NULL && static_tls_extra[0] != '\0') { 752 sz = parse_integer(static_tls_extra); 753 if (sz >= RTLD_STATIC_TLS_EXTRA && sz <= SIZE_T_MAX) 754 ld_static_tls_extra = sz; 755 } 756 rtld_recalc_dangerous_ld_env(); 757 ld_tracing = ld_get_env_var(LD_TRACE_LOADED_OBJECTS); 758 ld_utrace = ld_get_env_var(LD_UTRACE); 759 760 set_ld_elf_hints_path(); 761 dbg("%s is initialized, base address = %p", __progname, 762 (caddr_t)aux_info[AT_BASE]->a_un.a_ptr); 763 dbg("RTLD dynamic = %p", obj_rtld.dynamic); 764 dbg("RTLD pltgot = %p", obj_rtld.pltgot); 765 766 dbg("initializing thread locks"); 767 lockdflt_init(); 768 769 /* 770 * Load the main program, or process its program header if it is 771 * already loaded. 772 */ 773 if (fd != -1) { /* Load the main program. */ 774 dbg("loading main program"); 775 obj_main = map_object(fd, argv0, NULL, true); 776 close(fd); 777 if (obj_main == NULL) 778 rtld_die(); 779 max_stack_flags = obj_main->stack_flags; 780 } else { /* Main program already loaded. */ 781 dbg("processing main program's program header"); 782 assert(aux_info[AT_PHDR] != NULL); 783 phdr = (const Elf_Phdr *)aux_info[AT_PHDR]->a_un.a_ptr; 784 assert(aux_info[AT_PHNUM] != NULL); 785 phnum = aux_info[AT_PHNUM]->a_un.a_val; 786 assert(aux_info[AT_PHENT] != NULL); 787 assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr)); 788 assert(aux_info[AT_ENTRY] != NULL); 789 imgentry = (caddr_t)aux_info[AT_ENTRY]->a_un.a_ptr; 790 if ((obj_main = digest_phdr(phdr, phnum, imgentry, argv0)) == 791 NULL) 792 rtld_die(); 793 } 794 795 if (aux_info[AT_EXECPATH] != NULL && fd == -1) { 796 kexecpath = aux_info[AT_EXECPATH]->a_un.a_ptr; 797 dbg("AT_EXECPATH %p %s", kexecpath, kexecpath); 798 if (kexecpath[0] == '/') 799 obj_main->path = kexecpath; 800 else if (getcwd(buf, sizeof(buf)) == NULL || 801 strlcat(buf, "/", sizeof(buf)) >= sizeof(buf) || 802 strlcat(buf, kexecpath, sizeof(buf)) >= sizeof(buf)) 803 obj_main->path = xstrdup(argv0); 804 else 805 obj_main->path = xstrdup(buf); 806 } else { 807 dbg("No AT_EXECPATH or direct exec"); 808 obj_main->path = xstrdup(argv0); 809 } 810 dbg("obj_main path %s", obj_main->path); 811 obj_main->mainprog = true; 812 813 if (aux_info[AT_STACKPROT] != NULL && 814 aux_info[AT_STACKPROT]->a_un.a_val != 0) 815 stack_prot = aux_info[AT_STACKPROT]->a_un.a_val; 816 817 #ifndef COMPAT_libcompat 818 /* 819 * Get the actual dynamic linker pathname from the executable if 820 * possible. (It should always be possible.) That ensures that 821 * gdb will find the right dynamic linker even if a non-standard 822 * one is being used. 823 */ 824 if (obj_main->interp != NULL && 825 strcmp(obj_main->interp, obj_rtld.path) != 0) { 826 free(obj_rtld.path); 827 obj_rtld.path = xstrdup(obj_main->interp); 828 __progname = obj_rtld.path; 829 } 830 #endif 831 832 if (!digest_dynamic(obj_main, 0)) 833 rtld_die(); 834 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", 835 obj_main->path, obj_main->valid_hash_sysv, obj_main->valid_hash_gnu, 836 obj_main->dynsymcount); 837 838 linkmap_add(obj_main); 839 linkmap_add(&obj_rtld); 840 LD_UTRACE(UTRACE_LOAD_OBJECT, obj_main, obj_main->mapbase, 841 obj_main->mapsize, 0, obj_main->path); 842 LD_UTRACE(UTRACE_LOAD_OBJECT, &obj_rtld, obj_rtld.mapbase, 843 obj_rtld.mapsize, 0, obj_rtld.path); 844 845 /* Link the main program into the list of objects. */ 846 TAILQ_INSERT_HEAD(&obj_list, obj_main, next); 847 obj_count++; 848 obj_loads++; 849 850 /* Initialize a fake symbol for resolving undefined weak references. */ 851 sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE); 852 sym_zero.st_shndx = SHN_UNDEF; 853 sym_zero.st_value = -(uintptr_t)obj_main->relocbase; 854 855 if (!libmap_disable) 856 libmap_disable = (bool)lm_init(libmap_override); 857 858 if (aux_info[AT_KPRELOAD] != NULL && 859 aux_info[AT_KPRELOAD]->a_un.a_ptr != NULL) { 860 dbg("loading kernel vdso"); 861 if (load_kpreload(aux_info[AT_KPRELOAD]->a_un.a_ptr) == -1) 862 rtld_die(); 863 } 864 865 dbg("loading LD_PRELOAD_FDS libraries"); 866 if (load_preload_objects(ld_preload_fds, true) == -1) 867 rtld_die(); 868 869 dbg("loading LD_PRELOAD libraries"); 870 if (load_preload_objects(ld_preload, false) == -1) 871 rtld_die(); 872 preload_tail = globallist_curr(TAILQ_LAST(&obj_list, obj_entry_q)); 873 874 dbg("loading needed objects"); 875 if (load_needed_objects(obj_main, 876 ld_tracing != NULL ? RTLD_LO_TRACE : 0) == -1) 877 rtld_die(); 878 879 /* Make a list of all objects loaded at startup. */ 880 last_interposer = obj_main; 881 TAILQ_FOREACH(obj, &obj_list, next) { 882 if (obj->marker) 883 continue; 884 if (obj->z_interpose && obj != obj_main) { 885 objlist_put_after(&list_main, last_interposer, obj); 886 last_interposer = obj; 887 } else { 888 objlist_push_tail(&list_main, obj); 889 } 890 obj->refcount++; 891 } 892 893 dbg("checking for required versions"); 894 if (rtld_verify_versions(&list_main) == -1 && !ld_tracing) 895 rtld_die(); 896 897 if (ld_get_env_var(LD_SHOW_AUXV) != NULL) 898 dump_auxv(aux_info); 899 900 if (ld_tracing) { /* We're done */ 901 trace_loaded_objects(obj_main, true); 902 exit(0); 903 } 904 905 if (ld_get_env_var(LD_DUMP_REL_PRE) != NULL) { 906 dump_relocations(obj_main); 907 exit(0); 908 } 909 910 /* 911 * Processing tls relocations requires having the tls offsets 912 * initialized. Prepare offsets before starting initial 913 * relocation processing. 914 */ 915 dbg("initializing initial thread local storage offsets"); 916 STAILQ_FOREACH(entry, &list_main, link) { 917 /* 918 * Allocate all the initial objects out of the static TLS 919 * block even if they didn't ask for it. 920 */ 921 allocate_tls_offset(entry->obj); 922 } 923 924 if (!allocate_tls_offset_common(&tcb_list_entry_offset, 925 sizeof(struct tcb_list_entry), _Alignof(struct tcb_list_entry), 926 0)) { 927 /* 928 * This should be impossible as the static block size is not 929 * yet fixed, but catch and diagnose it failing if that ever 930 * changes or somehow turns out to be false. 931 */ 932 _rtld_error("Could not allocate offset for tcb_list_entry"); 933 rtld_die(); 934 } 935 dbg("tcb_list_entry_offset %zu", tcb_list_entry_offset); 936 937 if (relocate_objects(obj_main, 938 ld_bind_now != NULL && *ld_bind_now != '\0', &obj_rtld, 939 SYMLOOK_EARLY, NULL) == -1) 940 rtld_die(); 941 942 dbg("doing copy relocations"); 943 if (do_copy_relocations(obj_main) == -1) 944 rtld_die(); 945 946 if (ld_get_env_var(LD_DUMP_REL_POST) != NULL) { 947 dump_relocations(obj_main); 948 exit(0); 949 } 950 951 ifunc_init(aux_info); 952 953 /* 954 * Setup TLS for main thread. This must be done after the 955 * relocations are processed, since tls initialization section 956 * might be the subject for relocations. 957 */ 958 dbg("initializing initial thread local storage"); 959 allocate_initial_tls(globallist_curr(TAILQ_FIRST(&obj_list))); 960 961 dbg("initializing key program variables"); 962 set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : ""); 963 set_program_var("environ", env); 964 set_program_var("__elf_aux_vector", aux); 965 966 /* Make a list of init functions to call. */ 967 objlist_init(&initlist); 968 initlist_for_loaded_obj(globallist_curr(TAILQ_FIRST(&obj_list)), 969 preload_tail, &initlist); 970 971 r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */ 972 973 map_stacks_exec(NULL); 974 975 if (!obj_main->crt_no_init) { 976 /* 977 * Make sure we don't call the main program's init and fini 978 * functions for binaries linked with old crt1 which calls 979 * _init itself. 980 */ 981 obj_main->init = obj_main->fini = 0; 982 obj_main->preinit_array = obj_main->init_array = 983 obj_main->fini_array = NULL; 984 } 985 986 if (direct_exec) { 987 /* Set osrel for direct-execed binary */ 988 mib[0] = CTL_KERN; 989 mib[1] = KERN_PROC; 990 mib[2] = KERN_PROC_OSREL; 991 mib[3] = getpid(); 992 osrel = obj_main->osrel; 993 sz = sizeof(old_osrel); 994 dbg("setting osrel to %d", osrel); 995 (void)sysctl(mib, 4, &old_osrel, &sz, &osrel, sizeof(osrel)); 996 } 997 998 wlock_acquire(rtld_bind_lock, &lockstate); 999 1000 dbg("resolving ifuncs"); 1001 if (initlist_objects_ifunc(&initlist, 1002 ld_bind_now != NULL && *ld_bind_now != '\0', SYMLOOK_EARLY, 1003 &lockstate) == -1) 1004 rtld_die(); 1005 1006 rtld_exit_ptr = rtld_exit; 1007 if (obj_main->crt_no_init) 1008 preinit_main(); 1009 objlist_call_init(&initlist, &lockstate); 1010 _r_debug_postinit(&obj_main->linkmap); 1011 objlist_clear(&initlist); 1012 dbg("loading filtees"); 1013 TAILQ_FOREACH(obj, &obj_list, next) { 1014 if (obj->marker) 1015 continue; 1016 if (ld_loadfltr || obj->z_loadfltr) 1017 load_filtees(obj, 0, &lockstate); 1018 } 1019 1020 dbg("enforcing main obj relro"); 1021 if (obj_enforce_relro(obj_main) == -1) 1022 rtld_die(); 1023 1024 lock_release(rtld_bind_lock, &lockstate); 1025 1026 dbg("transferring control to program entry point = %p", 1027 obj_main->entry); 1028 1029 /* Return the exit procedure and the program entry point. */ 1030 *exit_proc = rtld_exit_ptr; 1031 *objp = obj_main; 1032 return ((func_ptr_type)obj_main->entry); 1033 } 1034 1035 /* 1036 * Fill in a DoneList with an allocation large enough to hold all of 1037 * the currently-loaded Keep this as a macro since it calls 1038 * alloca and we want that to occur within the scope of the caller. 1039 */ 1040 #define DLP_ALLOCA_LIMIT 100 /* 800 bytes on LP64 */ 1041 #define donelist_init(_DLP, _REQ) do { \ 1042 DoneList *_dlp = _DLP; \ 1043 SymLook *_r = _REQ; \ 1044 _dlp->num_alloc = obj_count, \ 1045 _dlp->req = NULL; \ 1046 if (_dlp->num_alloc > DLP_ALLOCA_LIMIT) { \ 1047 _dlp->objs = xcalloc(_dlp->num_alloc, sizeof(_dlp->objs[0])); \ 1048 if (_r != NULL && _r->donelist_mem == NULL) { \ 1049 _r->donelist_mem = _dlp->objs; \ 1050 _dlp->req = _r; \ 1051 } \ 1052 } else { \ 1053 _dlp->objs = alloca(_dlp->num_alloc * sizeof(_dlp->objs[0])); \ 1054 } \ 1055 _dlp->num_used = 0; \ 1056 } while (0) 1057 1058 static void 1059 donelist_free(DoneList *dlp) 1060 { 1061 if (dlp->num_alloc > DLP_ALLOCA_LIMIT) 1062 free(dlp->objs); 1063 if (dlp->req != NULL) 1064 dlp->req->donelist_mem = NULL; 1065 } 1066 1067 void * 1068 rtld_resolve_ifunc(const Obj_Entry *obj, const Elf_Sym *def) 1069 { 1070 void *ptr; 1071 Elf_Addr target; 1072 1073 ptr = (void *)make_function_pointer(def, obj); 1074 target = call_ifunc_resolver(ptr); 1075 return ((void *)target); 1076 } 1077 1078 Elf_Addr 1079 _rtld_bind(Obj_Entry *obj, Elf_Size reloff) 1080 { 1081 const Elf_Rel *rel; 1082 const Elf_Sym *def; 1083 const Obj_Entry *defobj; 1084 Elf_Addr *where; 1085 Elf_Addr target; 1086 RtldLockState lockstate; 1087 1088 relock: 1089 rlock_acquire(rtld_bind_lock, &lockstate); 1090 if (sigsetjmp(lockstate.env, 0) != 0) 1091 lock_upgrade(rtld_bind_lock, &lockstate); 1092 if (obj->pltrel) 1093 rel = (const Elf_Rel *)((const char *)obj->pltrel + reloff); 1094 else 1095 rel = (const Elf_Rel *)((const char *)obj->pltrela + reloff); 1096 1097 where = (Elf_Addr *)(obj->relocbase + rel->r_offset); 1098 def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, SYMLOOK_IN_PLT, 1099 NULL, &lockstate); 1100 if (def == NULL) 1101 rtld_die(); 1102 if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) { 1103 if (lockstate_wlocked(&lockstate)) { 1104 lock_release(rtld_bind_lock, &lockstate); 1105 goto relock; 1106 } 1107 target = (Elf_Addr)rtld_resolve_ifunc(defobj, def); 1108 } else { 1109 target = (Elf_Addr)(defobj->relocbase + def->st_value); 1110 } 1111 1112 dbg("\"%s\" in \"%s\" ==> %p in \"%s\"", defobj->strtab + def->st_name, 1113 obj->path == NULL ? NULL : basename(obj->path), (void *)target, 1114 defobj->path == NULL ? NULL : basename(defobj->path)); 1115 1116 /* 1117 * Write the new contents for the jmpslot. Note that depending on 1118 * architecture, the value which we need to return back to the 1119 * lazy binding trampoline may or may not be the target 1120 * address. The value returned from reloc_jmpslot() is the value 1121 * that the trampoline needs. 1122 */ 1123 target = reloc_jmpslot(where, target, defobj, obj, rel); 1124 lock_release(rtld_bind_lock, &lockstate); 1125 return (target); 1126 } 1127 1128 /* 1129 * Error reporting function. Use it like printf. If formats the message 1130 * into a buffer, and sets things up so that the next call to dlerror() 1131 * will return the message. 1132 */ 1133 void 1134 _rtld_error(const char *fmt, ...) 1135 { 1136 va_list ap; 1137 1138 va_start(ap, fmt); 1139 rtld_vsnprintf(lockinfo.dlerror_loc(), lockinfo.dlerror_loc_sz, fmt, 1140 ap); 1141 va_end(ap); 1142 *lockinfo.dlerror_seen() = 0; 1143 dbg("rtld_error: %s", lockinfo.dlerror_loc()); 1144 LD_UTRACE(UTRACE_RTLD_ERROR, NULL, NULL, 0, 0, lockinfo.dlerror_loc()); 1145 } 1146 1147 /* 1148 * Return a dynamically-allocated copy of the current error message, if any. 1149 */ 1150 static struct dlerror_save * 1151 errmsg_save(void) 1152 { 1153 struct dlerror_save *res; 1154 1155 res = xmalloc(sizeof(*res)); 1156 res->seen = *lockinfo.dlerror_seen(); 1157 if (res->seen == 0) 1158 res->msg = xstrdup(lockinfo.dlerror_loc()); 1159 return (res); 1160 } 1161 1162 /* 1163 * Restore the current error message from a copy which was previously saved 1164 * by errmsg_save(). The copy is freed. 1165 */ 1166 static void 1167 errmsg_restore(struct dlerror_save *saved_msg) 1168 { 1169 if (saved_msg == NULL || saved_msg->seen == 1) { 1170 *lockinfo.dlerror_seen() = 1; 1171 } else { 1172 *lockinfo.dlerror_seen() = 0; 1173 strlcpy(lockinfo.dlerror_loc(), saved_msg->msg, 1174 lockinfo.dlerror_loc_sz); 1175 free(saved_msg->msg); 1176 } 1177 free(saved_msg); 1178 } 1179 1180 static const char * 1181 basename(const char *name) 1182 { 1183 const char *p; 1184 1185 p = strrchr(name, '/'); 1186 return (p != NULL ? p + 1 : name); 1187 } 1188 1189 static struct utsname uts; 1190 1191 static char * 1192 origin_subst_one(Obj_Entry *obj, char *real, const char *kw, const char *subst, 1193 bool may_free) 1194 { 1195 char *p, *p1, *res, *resp; 1196 int subst_len, kw_len, subst_count, old_len, new_len; 1197 1198 kw_len = strlen(kw); 1199 1200 /* 1201 * First, count the number of the keyword occurrences, to 1202 * preallocate the final string. 1203 */ 1204 for (p = real, subst_count = 0;; p = p1 + kw_len, subst_count++) { 1205 p1 = strstr(p, kw); 1206 if (p1 == NULL) 1207 break; 1208 } 1209 1210 /* 1211 * If the keyword is not found, just return. 1212 * 1213 * Return non-substituted string if resolution failed. We 1214 * cannot do anything more reasonable, the failure mode of the 1215 * caller is unresolved library anyway. 1216 */ 1217 if (subst_count == 0 || (obj != NULL && !obj_resolve_origin(obj))) 1218 return (may_free ? real : xstrdup(real)); 1219 if (obj != NULL) 1220 subst = obj->origin_path; 1221 1222 /* 1223 * There is indeed something to substitute. Calculate the 1224 * length of the resulting string, and allocate it. 1225 */ 1226 subst_len = strlen(subst); 1227 old_len = strlen(real); 1228 new_len = old_len + (subst_len - kw_len) * subst_count; 1229 res = xmalloc(new_len + 1); 1230 1231 /* 1232 * Now, execute the substitution loop. 1233 */ 1234 for (p = real, resp = res, *resp = '\0';;) { 1235 p1 = strstr(p, kw); 1236 if (p1 != NULL) { 1237 /* Copy the prefix before keyword. */ 1238 memcpy(resp, p, p1 - p); 1239 resp += p1 - p; 1240 /* Keyword replacement. */ 1241 memcpy(resp, subst, subst_len); 1242 resp += subst_len; 1243 *resp = '\0'; 1244 p = p1 + kw_len; 1245 } else 1246 break; 1247 } 1248 1249 /* Copy to the end of string and finish. */ 1250 strcat(resp, p); 1251 if (may_free) 1252 free(real); 1253 return (res); 1254 } 1255 1256 static const struct { 1257 const char *kw; 1258 bool pass_obj; 1259 const char *subst; 1260 } tokens[] = { 1261 { .kw = "$ORIGIN", .pass_obj = true, .subst = NULL }, 1262 { .kw = "${ORIGIN}", .pass_obj = true, .subst = NULL }, 1263 { .kw = "$OSNAME", .pass_obj = false, .subst = uts.sysname }, 1264 { .kw = "${OSNAME}", .pass_obj = false, .subst = uts.sysname }, 1265 { .kw = "$OSREL", .pass_obj = false, .subst = uts.release }, 1266 { .kw = "${OSREL}", .pass_obj = false, .subst = uts.release }, 1267 { .kw = "$PLATFORM", .pass_obj = false, .subst = uts.machine }, 1268 { .kw = "${PLATFORM}", .pass_obj = false, .subst = uts.machine }, 1269 { .kw = "$LIB", .pass_obj = false, .subst = TOKEN_LIB }, 1270 { .kw = "${LIB}", .pass_obj = false, .subst = TOKEN_LIB }, 1271 }; 1272 1273 static char * 1274 origin_subst(Obj_Entry *obj, const char *real) 1275 { 1276 char *res; 1277 int i; 1278 1279 if (obj == NULL || !trust) 1280 return (xstrdup(real)); 1281 if (uts.sysname[0] == '\0') { 1282 if (uname(&uts) != 0) { 1283 _rtld_error("utsname failed: %d", errno); 1284 return (NULL); 1285 } 1286 } 1287 1288 /* __DECONST is safe here since without may_free real is unchanged */ 1289 res = __DECONST(char *, real); 1290 for (i = 0; i < (int)nitems(tokens); i++) { 1291 res = origin_subst_one(tokens[i].pass_obj ? obj : NULL, res, 1292 tokens[i].kw, tokens[i].subst, i != 0); 1293 } 1294 return (res); 1295 } 1296 1297 void 1298 rtld_die(void) 1299 { 1300 const char *msg = dlerror(); 1301 1302 if (msg == NULL) 1303 msg = "Fatal error"; 1304 rtld_fdputstr(STDERR_FILENO, _BASENAME_RTLD ": "); 1305 rtld_fdputstr(STDERR_FILENO, msg); 1306 rtld_fdputchar(STDERR_FILENO, '\n'); 1307 _exit(1); 1308 } 1309 1310 /* 1311 * Process a shared object's DYNAMIC section, and save the important 1312 * information in its Obj_Entry structure. 1313 */ 1314 static void 1315 digest_dynamic1(Obj_Entry *obj, int early, const Elf_Dyn **dyn_rpath, 1316 const Elf_Dyn **dyn_soname, const Elf_Dyn **dyn_runpath) 1317 { 1318 const Elf_Dyn *dynp; 1319 Needed_Entry **needed_tail = &obj->needed; 1320 Needed_Entry **needed_filtees_tail = &obj->needed_filtees; 1321 Needed_Entry **needed_aux_filtees_tail = &obj->needed_aux_filtees; 1322 const Elf_Hashelt *hashtab; 1323 const Elf32_Word *hashval; 1324 Elf32_Word bkt, nmaskwords; 1325 int bloom_size32; 1326 int plttype = DT_REL; 1327 1328 *dyn_rpath = NULL; 1329 *dyn_soname = NULL; 1330 *dyn_runpath = NULL; 1331 1332 obj->bind_now = false; 1333 dynp = obj->dynamic; 1334 if (dynp == NULL) 1335 return; 1336 for (; dynp->d_tag != DT_NULL; dynp++) { 1337 switch (dynp->d_tag) { 1338 case DT_REL: 1339 obj->rel = (const Elf_Rel *)(obj->relocbase + 1340 dynp->d_un.d_ptr); 1341 break; 1342 1343 case DT_RELSZ: 1344 obj->relsize = dynp->d_un.d_val; 1345 break; 1346 1347 case DT_RELENT: 1348 assert(dynp->d_un.d_val == sizeof(Elf_Rel)); 1349 break; 1350 1351 case DT_JMPREL: 1352 obj->pltrel = (const Elf_Rel *)(obj->relocbase + 1353 dynp->d_un.d_ptr); 1354 break; 1355 1356 case DT_PLTRELSZ: 1357 obj->pltrelsize = dynp->d_un.d_val; 1358 break; 1359 1360 case DT_RELA: 1361 obj->rela = (const Elf_Rela *)(obj->relocbase + 1362 dynp->d_un.d_ptr); 1363 break; 1364 1365 case DT_RELASZ: 1366 obj->relasize = dynp->d_un.d_val; 1367 break; 1368 1369 case DT_RELAENT: 1370 assert(dynp->d_un.d_val == sizeof(Elf_Rela)); 1371 break; 1372 1373 case DT_RELR: 1374 obj->relr = (const Elf_Relr *)(obj->relocbase + 1375 dynp->d_un.d_ptr); 1376 break; 1377 1378 case DT_RELRSZ: 1379 obj->relrsize = dynp->d_un.d_val; 1380 break; 1381 1382 case DT_RELRENT: 1383 assert(dynp->d_un.d_val == sizeof(Elf_Relr)); 1384 break; 1385 1386 case DT_PLTREL: 1387 plttype = dynp->d_un.d_val; 1388 assert( 1389 dynp->d_un.d_val == DT_REL || plttype == DT_RELA); 1390 break; 1391 1392 case DT_SYMTAB: 1393 obj->symtab = (const Elf_Sym *)(obj->relocbase + 1394 dynp->d_un.d_ptr); 1395 break; 1396 1397 case DT_SYMENT: 1398 assert(dynp->d_un.d_val == sizeof(Elf_Sym)); 1399 break; 1400 1401 case DT_STRTAB: 1402 obj->strtab = (const char *)(obj->relocbase + 1403 dynp->d_un.d_ptr); 1404 break; 1405 1406 case DT_STRSZ: 1407 obj->strsize = dynp->d_un.d_val; 1408 break; 1409 1410 case DT_VERNEED: 1411 obj->verneed = (const Elf_Verneed *)(obj->relocbase + 1412 dynp->d_un.d_val); 1413 break; 1414 1415 case DT_VERNEEDNUM: 1416 obj->verneednum = dynp->d_un.d_val; 1417 break; 1418 1419 case DT_VERDEF: 1420 obj->verdef = (const Elf_Verdef *)(obj->relocbase + 1421 dynp->d_un.d_val); 1422 break; 1423 1424 case DT_VERDEFNUM: 1425 obj->verdefnum = dynp->d_un.d_val; 1426 break; 1427 1428 case DT_VERSYM: 1429 obj->versyms = (const Elf_Versym *)(obj->relocbase + 1430 dynp->d_un.d_val); 1431 break; 1432 1433 case DT_HASH: { 1434 hashtab = (const Elf_Hashelt *)(obj->relocbase + 1435 dynp->d_un.d_ptr); 1436 obj->nbuckets = hashtab[0]; 1437 obj->nchains = hashtab[1]; 1438 obj->buckets = hashtab + 2; 1439 obj->chains = obj->buckets + obj->nbuckets; 1440 obj->valid_hash_sysv = obj->nbuckets > 0 && 1441 obj->nchains > 0 && obj->buckets != NULL; 1442 } break; 1443 1444 case DT_GNU_HASH: { 1445 hashtab = (const Elf_Hashelt *)(obj->relocbase + 1446 dynp->d_un.d_ptr); 1447 obj->nbuckets_gnu = hashtab[0]; 1448 obj->symndx_gnu = hashtab[1]; 1449 nmaskwords = hashtab[2]; 1450 bloom_size32 = (__ELF_WORD_SIZE / 32) * nmaskwords; 1451 obj->maskwords_bm_gnu = nmaskwords - 1; 1452 obj->shift2_gnu = hashtab[3]; 1453 obj->bloom_gnu = (const Elf_Addr *)(hashtab + 4); 1454 obj->buckets_gnu = hashtab + 4 + bloom_size32; 1455 obj->chain_zero_gnu = obj->buckets_gnu + 1456 obj->nbuckets_gnu - obj->symndx_gnu; 1457 /* Number of bitmask words is required to be power of 2 1458 */ 1459 obj->valid_hash_gnu = powerof2(nmaskwords) && 1460 obj->nbuckets_gnu > 0 && obj->buckets_gnu != NULL; 1461 } break; 1462 1463 case DT_NEEDED: 1464 if (!obj->rtld) { 1465 Needed_Entry *nep = NEW(Needed_Entry); 1466 nep->name = dynp->d_un.d_val; 1467 nep->obj = NULL; 1468 nep->next = NULL; 1469 1470 *needed_tail = nep; 1471 needed_tail = &nep->next; 1472 } 1473 break; 1474 1475 case DT_FILTER: 1476 if (!obj->rtld) { 1477 Needed_Entry *nep = NEW(Needed_Entry); 1478 nep->name = dynp->d_un.d_val; 1479 nep->obj = NULL; 1480 nep->next = NULL; 1481 1482 *needed_filtees_tail = nep; 1483 needed_filtees_tail = &nep->next; 1484 1485 if (obj->linkmap.l_refname == NULL) 1486 obj->linkmap.l_refname = 1487 (char *)dynp->d_un.d_val; 1488 } 1489 break; 1490 1491 case DT_AUXILIARY: 1492 if (!obj->rtld) { 1493 Needed_Entry *nep = NEW(Needed_Entry); 1494 nep->name = dynp->d_un.d_val; 1495 nep->obj = NULL; 1496 nep->next = NULL; 1497 1498 *needed_aux_filtees_tail = nep; 1499 needed_aux_filtees_tail = &nep->next; 1500 } 1501 break; 1502 1503 case DT_PLTGOT: 1504 obj->pltgot = (Elf_Addr *)(obj->relocbase + 1505 dynp->d_un.d_ptr); 1506 break; 1507 1508 case DT_TEXTREL: 1509 obj->textrel = true; 1510 break; 1511 1512 case DT_SYMBOLIC: 1513 obj->symbolic = true; 1514 break; 1515 1516 case DT_RPATH: 1517 /* 1518 * We have to wait until later to process this, because 1519 * we might not have gotten the address of the string 1520 * table yet. 1521 */ 1522 *dyn_rpath = dynp; 1523 break; 1524 1525 case DT_SONAME: 1526 *dyn_soname = dynp; 1527 break; 1528 1529 case DT_RUNPATH: 1530 *dyn_runpath = dynp; 1531 break; 1532 1533 case DT_INIT: 1534 obj->init = (uintptr_t)(obj->relocbase + 1535 dynp->d_un.d_ptr); 1536 break; 1537 1538 case DT_PREINIT_ARRAY: 1539 obj->preinit_array = (uintptr_t *)(obj->relocbase + 1540 dynp->d_un.d_ptr); 1541 break; 1542 1543 case DT_PREINIT_ARRAYSZ: 1544 obj->preinit_array_num = dynp->d_un.d_val / 1545 sizeof(uintptr_t); 1546 break; 1547 1548 case DT_INIT_ARRAY: 1549 obj->init_array = (uintptr_t *)(obj->relocbase + 1550 dynp->d_un.d_ptr); 1551 break; 1552 1553 case DT_INIT_ARRAYSZ: 1554 obj->init_array_num = dynp->d_un.d_val / 1555 sizeof(uintptr_t); 1556 break; 1557 1558 case DT_FINI: 1559 obj->fini = (uintptr_t)(obj->relocbase + 1560 dynp->d_un.d_ptr); 1561 break; 1562 1563 case DT_FINI_ARRAY: 1564 obj->fini_array = (uintptr_t *)(obj->relocbase + 1565 dynp->d_un.d_ptr); 1566 break; 1567 1568 case DT_FINI_ARRAYSZ: 1569 obj->fini_array_num = dynp->d_un.d_val / 1570 sizeof(uintptr_t); 1571 break; 1572 1573 case DT_DEBUG: 1574 if (!early) 1575 dbg("Filling in DT_DEBUG entry"); 1576 (__DECONST(Elf_Dyn *, dynp))->d_un.d_ptr = 1577 (Elf_Addr)&r_debug; 1578 break; 1579 1580 case DT_FLAGS: 1581 if (dynp->d_un.d_val & DF_ORIGIN) 1582 obj->z_origin = true; 1583 if (dynp->d_un.d_val & DF_SYMBOLIC) 1584 obj->symbolic = true; 1585 if (dynp->d_un.d_val & DF_TEXTREL) 1586 obj->textrel = true; 1587 if (dynp->d_un.d_val & DF_BIND_NOW) 1588 obj->bind_now = true; 1589 if (dynp->d_un.d_val & DF_STATIC_TLS) 1590 obj->static_tls = true; 1591 break; 1592 1593 case DT_FLAGS_1: 1594 if (dynp->d_un.d_val & DF_1_NOOPEN) 1595 obj->z_noopen = true; 1596 if (dynp->d_un.d_val & DF_1_ORIGIN) 1597 obj->z_origin = true; 1598 if (dynp->d_un.d_val & DF_1_GLOBAL) 1599 obj->z_global = true; 1600 if (dynp->d_un.d_val & DF_1_BIND_NOW) 1601 obj->bind_now = true; 1602 if (dynp->d_un.d_val & DF_1_NODELETE) 1603 obj->z_nodelete = true; 1604 if (dynp->d_un.d_val & DF_1_LOADFLTR) 1605 obj->z_loadfltr = true; 1606 if (dynp->d_un.d_val & DF_1_INTERPOSE) 1607 obj->z_interpose = true; 1608 if (dynp->d_un.d_val & DF_1_NODEFLIB) 1609 obj->z_nodeflib = true; 1610 if (dynp->d_un.d_val & DF_1_PIE) 1611 obj->z_pie = true; 1612 if (dynp->d_un.d_val & DF_1_INITFIRST) 1613 obj->z_initfirst = true; 1614 break; 1615 1616 default: 1617 if (arch_digest_dynamic(obj, dynp)) 1618 break; 1619 1620 if (!early) { 1621 dbg("Ignoring d_tag %ld = %#lx", 1622 (long)dynp->d_tag, (long)dynp->d_tag); 1623 } 1624 break; 1625 } 1626 } 1627 1628 obj->traced = false; 1629 1630 if (plttype == DT_RELA) { 1631 obj->pltrela = (const Elf_Rela *)obj->pltrel; 1632 obj->pltrel = NULL; 1633 obj->pltrelasize = obj->pltrelsize; 1634 obj->pltrelsize = 0; 1635 } 1636 1637 /* Determine size of dynsym table (equal to nchains of sysv hash) */ 1638 if (obj->valid_hash_sysv) 1639 obj->dynsymcount = obj->nchains; 1640 else if (obj->valid_hash_gnu) { 1641 obj->dynsymcount = 0; 1642 for (bkt = 0; bkt < obj->nbuckets_gnu; bkt++) { 1643 if (obj->buckets_gnu[bkt] == 0) 1644 continue; 1645 hashval = &obj->chain_zero_gnu[obj->buckets_gnu[bkt]]; 1646 do 1647 obj->dynsymcount++; 1648 while ((*hashval++ & 1u) == 0); 1649 } 1650 obj->dynsymcount += obj->symndx_gnu; 1651 } 1652 1653 if (obj->linkmap.l_refname != NULL) 1654 obj->linkmap.l_refname = obj->strtab + 1655 (unsigned long)obj->linkmap.l_refname; 1656 } 1657 1658 static bool 1659 obj_resolve_origin(Obj_Entry *obj) 1660 { 1661 if (obj->origin_path != NULL) 1662 return (true); 1663 obj->origin_path = xmalloc(PATH_MAX); 1664 return (rtld_dirname_abs(obj->path, obj->origin_path) != -1); 1665 } 1666 1667 static bool 1668 digest_dynamic2(Obj_Entry *obj, const Elf_Dyn *dyn_rpath, 1669 const Elf_Dyn *dyn_soname, const Elf_Dyn *dyn_runpath) 1670 { 1671 if (obj->z_origin && !obj_resolve_origin(obj)) 1672 return (false); 1673 1674 if (dyn_runpath != NULL) { 1675 obj->runpath = (const char *)obj->strtab + 1676 dyn_runpath->d_un.d_val; 1677 obj->runpath = origin_subst(obj, obj->runpath); 1678 } else if (dyn_rpath != NULL) { 1679 obj->rpath = (const char *)obj->strtab + dyn_rpath->d_un.d_val; 1680 obj->rpath = origin_subst(obj, obj->rpath); 1681 } 1682 if (dyn_soname != NULL) 1683 object_add_name(obj, obj->strtab + dyn_soname->d_un.d_val); 1684 return (true); 1685 } 1686 1687 static bool 1688 digest_dynamic(Obj_Entry *obj, int early) 1689 { 1690 const Elf_Dyn *dyn_rpath; 1691 const Elf_Dyn *dyn_soname; 1692 const Elf_Dyn *dyn_runpath; 1693 1694 digest_dynamic1(obj, early, &dyn_rpath, &dyn_soname, &dyn_runpath); 1695 return (digest_dynamic2(obj, dyn_rpath, dyn_soname, dyn_runpath)); 1696 } 1697 1698 /* 1699 * Process a shared object's program header. This is used only for the 1700 * main program, when the kernel has already loaded the main program 1701 * into memory before calling the dynamic linker. It creates and 1702 * returns an Obj_Entry structure. 1703 */ 1704 static Obj_Entry * 1705 digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path) 1706 { 1707 Obj_Entry *obj; 1708 const Elf_Phdr *phlimit = phdr + phnum; 1709 const Elf_Phdr *ph; 1710 Elf_Addr note_start, note_end; 1711 int nsegs = 0; 1712 1713 obj = obj_new(); 1714 for (ph = phdr; ph < phlimit; ph++) { 1715 if (ph->p_type != PT_PHDR) 1716 continue; 1717 1718 obj->phdr = phdr; 1719 obj->phnum = ph->p_memsz / sizeof(*ph); 1720 obj->relocbase = __DECONST(char *, phdr) - ph->p_vaddr; 1721 break; 1722 } 1723 1724 obj->stack_flags = PF_X | PF_R | PF_W; 1725 1726 for (ph = phdr; ph < phlimit; ph++) { 1727 switch (ph->p_type) { 1728 case PT_INTERP: 1729 obj->interp = (const char *)(ph->p_vaddr + 1730 obj->relocbase); 1731 break; 1732 1733 case PT_LOAD: 1734 if (nsegs == 0) { /* First load segment */ 1735 obj->vaddrbase = rtld_trunc_page(ph->p_vaddr); 1736 obj->mapbase = obj->vaddrbase + obj->relocbase; 1737 } else { /* Last load segment */ 1738 obj->mapsize = rtld_round_page( 1739 ph->p_vaddr + ph->p_memsz) - 1740 obj->vaddrbase; 1741 } 1742 nsegs++; 1743 break; 1744 1745 case PT_DYNAMIC: 1746 obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + 1747 obj->relocbase); 1748 break; 1749 1750 case PT_TLS: 1751 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; 1789 const char *note_name; 1790 uintptr_t p; 1791 1792 for (note = (const Elf_Note *)note_start; (Elf_Addr)note < note_end; 1793 note = (const Elf_Note *)((const char *)(note + 1) + 1794 roundup2(note->n_namesz, sizeof(Elf32_Addr)) + 1795 roundup2(note->n_descsz, sizeof(Elf32_Addr)))) { 1796 if (arch_digest_note(obj, note)) 1797 continue; 1798 1799 if (note->n_namesz != sizeof(NOTE_FREEBSD_VENDOR) || 1800 note->n_descsz != sizeof(int32_t)) 1801 continue; 1802 if (note->n_type != NT_FREEBSD_ABI_TAG && 1803 note->n_type != NT_FREEBSD_FEATURE_CTL && 1804 note->n_type != NT_FREEBSD_NOINIT_TAG) 1805 continue; 1806 note_name = (const char *)(note + 1); 1807 if (strncmp(NOTE_FREEBSD_VENDOR, note_name, 1808 sizeof(NOTE_FREEBSD_VENDOR)) != 0) 1809 continue; 1810 switch (note->n_type) { 1811 case NT_FREEBSD_ABI_TAG: 1812 /* FreeBSD osrel note */ 1813 p = (uintptr_t)(note + 1); 1814 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1815 obj->osrel = *(const int32_t *)(p); 1816 dbg("note osrel %d", obj->osrel); 1817 break; 1818 case NT_FREEBSD_FEATURE_CTL: 1819 /* FreeBSD ABI feature control note */ 1820 p = (uintptr_t)(note + 1); 1821 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1822 obj->fctl0 = *(const uint32_t *)(p); 1823 dbg("note fctl0 %#x", obj->fctl0); 1824 break; 1825 case NT_FREEBSD_NOINIT_TAG: 1826 /* FreeBSD 'crt does not call init' note */ 1827 obj->crt_no_init = true; 1828 dbg("note crt_no_init"); 1829 break; 1830 } 1831 } 1832 } 1833 1834 static Obj_Entry * 1835 dlcheck(void *handle) 1836 { 1837 Obj_Entry *obj; 1838 1839 TAILQ_FOREACH(obj, &obj_list, next) { 1840 if (obj == (Obj_Entry *)handle) 1841 break; 1842 } 1843 1844 if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) { 1845 _rtld_error("Invalid shared object handle %p", handle); 1846 return (NULL); 1847 } 1848 return (obj); 1849 } 1850 1851 /* 1852 * If the given object is already in the donelist, return true. Otherwise 1853 * add the object to the list and return false. 1854 */ 1855 static bool 1856 donelist_check(DoneList *dlp, const Obj_Entry *obj) 1857 { 1858 unsigned int i; 1859 1860 for (i = 0; i < dlp->num_used; i++) 1861 if (dlp->objs[i] == obj) 1862 return (true); 1863 /* 1864 * Our donelist allocation should always be sufficient. But if 1865 * our threads locking isn't working properly, more shared objects 1866 * could have been loaded since we allocated the list. That should 1867 * never happen, but we'll handle it properly just in case it does. 1868 */ 1869 if (dlp->num_used < dlp->num_alloc) 1870 dlp->objs[dlp->num_used++] = obj; 1871 return (false); 1872 } 1873 1874 /* 1875 * SysV hash function for symbol table lookup. It is a slightly optimized 1876 * version of the hash specified by the System V ABI. 1877 */ 1878 Elf32_Word 1879 elf_hash(const char *name) 1880 { 1881 const unsigned char *p = (const unsigned char *)name; 1882 Elf32_Word h = 0; 1883 1884 while (*p != '\0') { 1885 h = (h << 4) + *p++; 1886 h ^= (h >> 24) & 0xf0; 1887 } 1888 return (h & 0x0fffffff); 1889 } 1890 1891 /* 1892 * The GNU hash function is the Daniel J. Bernstein hash clipped to 32 bits 1893 * unsigned in case it's implemented with a wider type. 1894 */ 1895 static uint32_t 1896 gnu_hash(const char *s) 1897 { 1898 uint32_t h; 1899 unsigned char c; 1900 1901 h = 5381; 1902 for (c = *s; c != '\0'; c = *++s) 1903 h = h * 33 + c; 1904 return (h & 0xffffffff); 1905 } 1906 1907 /* 1908 * Find the library with the given name, and return its full pathname. 1909 * The returned string is dynamically allocated. Generates an error 1910 * message and returns NULL if the library cannot be found. 1911 * 1912 * If the second argument is non-NULL, then it refers to an already- 1913 * loaded shared object, whose library search path will be searched. 1914 * 1915 * If a library is successfully located via LD_LIBRARY_PATH_FDS, its 1916 * descriptor (which is close-on-exec) will be passed out via the third 1917 * argument. 1918 * 1919 * The search order is: 1920 * DT_RPATH in the referencing file _unless_ DT_RUNPATH is present (1) 1921 * DT_RPATH of the main object if DSO without defined DT_RUNPATH (1) 1922 * LD_LIBRARY_PATH 1923 * DT_RUNPATH in the referencing file 1924 * ldconfig hints (if -z nodefaultlib, filter out default library directories 1925 * from list) 1926 * /lib:/usr/lib _unless_ the referencing file is linked with -z nodefaultlib 1927 * 1928 * (1) Handled in digest_dynamic2 - rpath left NULL if runpath defined. 1929 */ 1930 static char * 1931 find_library(const char *xname, const Obj_Entry *refobj, int *fdp) 1932 { 1933 char *pathname, *refobj_path; 1934 const char *name; 1935 bool nodeflib, objgiven; 1936 1937 objgiven = refobj != NULL; 1938 1939 if (libmap_disable || !objgiven || 1940 (name = lm_find(refobj->path, xname)) == NULL) 1941 name = xname; 1942 1943 if (strchr(name, '/') != NULL) { /* Hard coded pathname */ 1944 if (name[0] != '/' && !trust) { 1945 _rtld_error( 1946 "Absolute pathname required for shared object \"%s\"", 1947 name); 1948 return (NULL); 1949 } 1950 return (origin_subst(__DECONST(Obj_Entry *, refobj), 1951 __DECONST(char *, name))); 1952 } 1953 1954 dbg(" Searching for \"%s\"", name); 1955 refobj_path = objgiven ? refobj->path : NULL; 1956 1957 /* 1958 * If refobj->rpath != NULL, then refobj->runpath is NULL. Fall 1959 * back to pre-conforming behaviour if user requested so with 1960 * LD_LIBRARY_PATH_RPATH environment variable and ignore -z 1961 * nodeflib. 1962 */ 1963 if (objgiven && refobj->rpath != NULL && ld_library_path_rpath) { 1964 pathname = search_library_path(name, ld_library_path, 1965 refobj_path, fdp); 1966 if (pathname != NULL) 1967 return (pathname); 1968 if (refobj != NULL) { 1969 pathname = search_library_path(name, refobj->rpath, 1970 refobj_path, fdp); 1971 if (pathname != NULL) 1972 return (pathname); 1973 } 1974 pathname = search_library_pathfds(name, ld_library_dirs, fdp); 1975 if (pathname != NULL) 1976 return (pathname); 1977 pathname = search_library_path(name, gethints(false), 1978 refobj_path, fdp); 1979 if (pathname != NULL) 1980 return (pathname); 1981 pathname = search_library_path(name, ld_standard_library_path, 1982 refobj_path, fdp); 1983 if (pathname != NULL) 1984 return (pathname); 1985 } else { 1986 nodeflib = objgiven ? refobj->z_nodeflib : false; 1987 if (objgiven) { 1988 pathname = search_library_path(name, refobj->rpath, 1989 refobj->path, fdp); 1990 if (pathname != NULL) 1991 return (pathname); 1992 } 1993 if (objgiven && refobj->runpath == NULL && refobj != obj_main) { 1994 pathname = search_library_path(name, obj_main->rpath, 1995 refobj_path, fdp); 1996 if (pathname != NULL) 1997 return (pathname); 1998 } 1999 pathname = search_library_path(name, ld_library_path, 2000 refobj_path, fdp); 2001 if (pathname != NULL) 2002 return (pathname); 2003 if (objgiven) { 2004 pathname = search_library_path(name, refobj->runpath, 2005 refobj_path, fdp); 2006 if (pathname != NULL) 2007 return (pathname); 2008 } 2009 pathname = search_library_pathfds(name, ld_library_dirs, fdp); 2010 if (pathname != NULL) 2011 return (pathname); 2012 pathname = search_library_path(name, gethints(nodeflib), 2013 refobj_path, fdp); 2014 if (pathname != NULL) 2015 return (pathname); 2016 if (objgiven && !nodeflib) { 2017 pathname = search_library_path(name, 2018 ld_standard_library_path, refobj_path, fdp); 2019 if (pathname != NULL) 2020 return (pathname); 2021 } 2022 } 2023 2024 if (objgiven && refobj->path != NULL) { 2025 _rtld_error( 2026 "Shared object \"%s\" not found, required by \"%s\"", 2027 name, basename(refobj->path)); 2028 } else { 2029 _rtld_error("Shared object \"%s\" not found", name); 2030 } 2031 return (NULL); 2032 } 2033 2034 /* 2035 * Given a symbol number in a referencing object, find the corresponding 2036 * definition of the symbol. Returns a pointer to the symbol, or NULL if 2037 * no definition was found. Returns a pointer to the Obj_Entry of the 2038 * defining object via the reference parameter DEFOBJ_OUT. 2039 */ 2040 const Elf_Sym * 2041 find_symdef(unsigned long symnum, const Obj_Entry *refobj, 2042 const Obj_Entry **defobj_out, int flags, SymCache *cache, 2043 RtldLockState *lockstate) 2044 { 2045 const Elf_Sym *ref; 2046 const Elf_Sym *def; 2047 const Obj_Entry *defobj; 2048 const Ver_Entry *ve; 2049 SymLook req; 2050 const char *name; 2051 int res; 2052 2053 /* 2054 * If we have already found this symbol, get the information from 2055 * the cache. 2056 */ 2057 if (symnum >= refobj->dynsymcount) 2058 return (NULL); /* Bad object */ 2059 if (cache != NULL && cache[symnum].sym != NULL) { 2060 *defobj_out = cache[symnum].obj; 2061 return (cache[symnum].sym); 2062 } 2063 2064 ref = refobj->symtab + symnum; 2065 name = refobj->strtab + ref->st_name; 2066 def = NULL; 2067 defobj = NULL; 2068 ve = NULL; 2069 2070 /* 2071 * We don't have to do a full scale lookup if the symbol is local. 2072 * We know it will bind to the instance in this load module; to 2073 * which we already have a pointer (ie ref). By not doing a lookup, 2074 * we not only improve performance, but it also avoids unresolvable 2075 * symbols when local symbols are not in the hash table. This has 2076 * been seen with the ia64 toolchain. 2077 */ 2078 if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) { 2079 if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) { 2080 _rtld_error("%s: Bogus symbol table entry %lu", 2081 refobj->path, symnum); 2082 } 2083 symlook_init(&req, name); 2084 req.flags = flags; 2085 ve = req.ventry = fetch_ventry(refobj, symnum); 2086 req.lockstate = lockstate; 2087 res = symlook_default(&req, refobj); 2088 if (res == 0) { 2089 def = req.sym_out; 2090 defobj = req.defobj_out; 2091 } 2092 } else { 2093 def = ref; 2094 defobj = refobj; 2095 } 2096 2097 /* 2098 * If we found no definition and the reference is weak, treat the 2099 * symbol as having the value zero. 2100 */ 2101 if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) { 2102 def = &sym_zero; 2103 defobj = obj_main; 2104 } 2105 2106 if (def != NULL) { 2107 *defobj_out = defobj; 2108 /* 2109 * Record the information in the cache to avoid subsequent 2110 * lookups. 2111 */ 2112 if (cache != NULL) { 2113 cache[symnum].sym = def; 2114 cache[symnum].obj = defobj; 2115 } 2116 } else { 2117 if (refobj != &obj_rtld) 2118 _rtld_error("%s: Undefined symbol \"%s%s%s\"", 2119 refobj->path, name, ve != NULL ? "@" : "", 2120 ve != NULL ? ve->name : ""); 2121 } 2122 return (def); 2123 } 2124 2125 /* Convert between native byte order and forced little resp. big endian. */ 2126 #define COND_SWAP(n) (is_le ? le32toh(n) : be32toh(n)) 2127 2128 /* 2129 * Return the search path from the ldconfig hints file, reading it if 2130 * necessary. If nostdlib is true, then the default search paths are 2131 * not added to result. 2132 * 2133 * Returns NULL if there are problems with the hints file, 2134 * or if the search path there is empty. 2135 */ 2136 static const char * 2137 gethints(bool nostdlib) 2138 { 2139 static char *filtered_path; 2140 static const char *hints; 2141 static struct elfhints_hdr hdr; 2142 struct fill_search_info_args sargs, hargs; 2143 struct dl_serinfo smeta, hmeta, *SLPinfo, *hintinfo; 2144 struct dl_serpath *SLPpath, *hintpath; 2145 char *p; 2146 struct stat hint_stat; 2147 unsigned int SLPndx, hintndx, fndx, fcount; 2148 int fd; 2149 size_t flen; 2150 uint32_t dl; 2151 uint32_t magic; /* Magic number */ 2152 uint32_t version; /* File version (1) */ 2153 uint32_t strtab; /* Offset of string table in file */ 2154 uint32_t dirlist; /* Offset of directory list in string table */ 2155 uint32_t dirlistlen; /* strlen(dirlist) */ 2156 bool is_le; /* Does the hints file use little endian */ 2157 bool skip; 2158 2159 /* First call, read the hints file */ 2160 if (hints == NULL) { 2161 /* Keep from trying again in case the hints file is bad. */ 2162 hints = ""; 2163 2164 if ((fd = open(ld_elf_hints_path, O_RDONLY | O_CLOEXEC)) == 2165 -1) { 2166 dbg("failed to open hints file \"%s\"", 2167 ld_elf_hints_path); 2168 return (NULL); 2169 } 2170 2171 /* 2172 * Check of hdr.dirlistlen value against type limit 2173 * intends to pacify static analyzers. Further 2174 * paranoia leads to checks that dirlist is fully 2175 * contained in the file range. 2176 */ 2177 if (read(fd, &hdr, sizeof hdr) != sizeof hdr) { 2178 dbg("failed to read %lu bytes from hints file \"%s\"", 2179 (u_long)sizeof hdr, ld_elf_hints_path); 2180 cleanup1: 2181 close(fd); 2182 hdr.dirlistlen = 0; 2183 return (NULL); 2184 } 2185 dbg("host byte-order: %s-endian", 2186 le32toh(1) == 1 ? "little" : "big"); 2187 dbg("hints file byte-order: %s-endian", 2188 hdr.magic == htole32(ELFHINTS_MAGIC) ? "little" : "big"); 2189 is_le = /*htole32(1) == 1 || */ hdr.magic == 2190 htole32(ELFHINTS_MAGIC); 2191 magic = COND_SWAP(hdr.magic); 2192 version = COND_SWAP(hdr.version); 2193 strtab = COND_SWAP(hdr.strtab); 2194 dirlist = COND_SWAP(hdr.dirlist); 2195 dirlistlen = COND_SWAP(hdr.dirlistlen); 2196 if (magic != ELFHINTS_MAGIC) { 2197 dbg("invalid magic number %#08x (expected: %#08x)", 2198 magic, ELFHINTS_MAGIC); 2199 goto cleanup1; 2200 } 2201 if (version != 1) { 2202 dbg("hints file version %d (expected: 1)", version); 2203 goto cleanup1; 2204 } 2205 if (dirlistlen > UINT_MAX / 2) { 2206 dbg("directory list is to long: %d > %d", dirlistlen, 2207 UINT_MAX / 2); 2208 goto cleanup1; 2209 } 2210 if (fstat(fd, &hint_stat) == -1) { 2211 dbg("failed to find length of hints file \"%s\"", 2212 ld_elf_hints_path); 2213 goto cleanup1; 2214 } 2215 dl = strtab; 2216 if (dl + dirlist < dl) { 2217 dbg("invalid string table position %d", dl); 2218 goto cleanup1; 2219 } 2220 dl += dirlist; 2221 if (dl + dirlistlen < dl) { 2222 dbg("invalid directory list offset %d", dirlist); 2223 goto cleanup1; 2224 } 2225 dl += dirlistlen; 2226 if (dl > hint_stat.st_size) { 2227 dbg("hints file \"%s\" is truncated (%d vs. %jd bytes)", 2228 ld_elf_hints_path, dl, 2229 (uintmax_t)hint_stat.st_size); 2230 goto cleanup1; 2231 } 2232 p = xmalloc(dirlistlen + 1); 2233 if (pread(fd, p, dirlistlen + 1, strtab + dirlist) != 2234 (ssize_t)dirlistlen + 1 || p[dirlistlen] != '\0') { 2235 free(p); 2236 dbg( 2237 "failed to read %d bytes starting at %d from hints file \"%s\"", 2238 dirlistlen + 1, strtab + dirlist, 2239 ld_elf_hints_path); 2240 goto cleanup1; 2241 } 2242 hints = p; 2243 close(fd); 2244 } 2245 2246 /* 2247 * If caller agreed to receive list which includes the default 2248 * paths, we are done. Otherwise, if we still did not 2249 * calculated filtered result, do it now. 2250 */ 2251 if (!nostdlib) 2252 return (hints[0] != '\0' ? hints : NULL); 2253 if (filtered_path != NULL) 2254 goto filt_ret; 2255 2256 /* 2257 * Obtain the list of all configured search paths, and the 2258 * list of the default paths. 2259 * 2260 * First estimate the size of the results. 2261 */ 2262 smeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 2263 smeta.dls_cnt = 0; 2264 hmeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 2265 hmeta.dls_cnt = 0; 2266 2267 sargs.request = RTLD_DI_SERINFOSIZE; 2268 sargs.serinfo = &smeta; 2269 hargs.request = RTLD_DI_SERINFOSIZE; 2270 hargs.serinfo = &hmeta; 2271 2272 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 2273 &sargs); 2274 path_enumerate(hints, fill_search_info, NULL, &hargs); 2275 2276 SLPinfo = xmalloc(smeta.dls_size); 2277 hintinfo = xmalloc(hmeta.dls_size); 2278 2279 /* 2280 * Next fetch both sets of paths. 2281 */ 2282 sargs.request = RTLD_DI_SERINFO; 2283 sargs.serinfo = SLPinfo; 2284 sargs.serpath = &SLPinfo->dls_serpath[0]; 2285 sargs.strspace = (char *)&SLPinfo->dls_serpath[smeta.dls_cnt]; 2286 2287 hargs.request = RTLD_DI_SERINFO; 2288 hargs.serinfo = hintinfo; 2289 hargs.serpath = &hintinfo->dls_serpath[0]; 2290 hargs.strspace = (char *)&hintinfo->dls_serpath[hmeta.dls_cnt]; 2291 2292 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 2293 &sargs); 2294 path_enumerate(hints, fill_search_info, NULL, &hargs); 2295 2296 /* 2297 * Now calculate the difference between two sets, by excluding 2298 * standard paths from the full set. 2299 */ 2300 fndx = 0; 2301 fcount = 0; 2302 filtered_path = xmalloc(dirlistlen + 1); 2303 hintpath = &hintinfo->dls_serpath[0]; 2304 for (hintndx = 0; hintndx < hmeta.dls_cnt; hintndx++, hintpath++) { 2305 skip = false; 2306 SLPpath = &SLPinfo->dls_serpath[0]; 2307 /* 2308 * Check each standard path against current. 2309 */ 2310 for (SLPndx = 0; SLPndx < smeta.dls_cnt; SLPndx++, SLPpath++) { 2311 /* matched, skip the path */ 2312 if (!strcmp(hintpath->dls_name, SLPpath->dls_name)) { 2313 skip = true; 2314 break; 2315 } 2316 } 2317 if (skip) 2318 continue; 2319 /* 2320 * Not matched against any standard path, add the path 2321 * to result. Separate consequtive paths with ':'. 2322 */ 2323 if (fcount > 0) { 2324 filtered_path[fndx] = ':'; 2325 fndx++; 2326 } 2327 fcount++; 2328 flen = strlen(hintpath->dls_name); 2329 strncpy((filtered_path + fndx), hintpath->dls_name, flen); 2330 fndx += flen; 2331 } 2332 filtered_path[fndx] = '\0'; 2333 2334 free(SLPinfo); 2335 free(hintinfo); 2336 2337 filt_ret: 2338 return (filtered_path[0] != '\0' ? filtered_path : NULL); 2339 } 2340 2341 static void 2342 init_dag(Obj_Entry *root) 2343 { 2344 const Needed_Entry *needed; 2345 const Objlist_Entry *elm; 2346 DoneList donelist; 2347 2348 if (root->dag_inited) 2349 return; 2350 donelist_init(&donelist, NULL); 2351 2352 /* Root object belongs to own DAG. */ 2353 objlist_push_tail(&root->dldags, root); 2354 objlist_push_tail(&root->dagmembers, root); 2355 donelist_check(&donelist, root); 2356 2357 /* 2358 * Add dependencies of root object to DAG in breadth order 2359 * by exploiting the fact that each new object get added 2360 * to the tail of the dagmembers list. 2361 */ 2362 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2363 for (needed = elm->obj->needed; needed != NULL; 2364 needed = needed->next) { 2365 if (needed->obj == NULL || 2366 donelist_check(&donelist, needed->obj)) 2367 continue; 2368 objlist_push_tail(&needed->obj->dldags, root); 2369 objlist_push_tail(&root->dagmembers, needed->obj); 2370 } 2371 } 2372 root->dag_inited = true; 2373 donelist_free(&donelist); 2374 } 2375 2376 static void 2377 init_marker(Obj_Entry *marker) 2378 { 2379 bzero(marker, sizeof(*marker)); 2380 marker->marker = true; 2381 } 2382 2383 Obj_Entry * 2384 globallist_curr(const Obj_Entry *obj) 2385 { 2386 for (;;) { 2387 if (obj == NULL) 2388 return (NULL); 2389 if (!obj->marker) 2390 return (__DECONST(Obj_Entry *, obj)); 2391 obj = TAILQ_PREV(obj, obj_entry_q, next); 2392 } 2393 } 2394 2395 Obj_Entry * 2396 globallist_next(const Obj_Entry *obj) 2397 { 2398 for (;;) { 2399 obj = TAILQ_NEXT(obj, next); 2400 if (obj == NULL) 2401 return (NULL); 2402 if (!obj->marker) 2403 return (__DECONST(Obj_Entry *, obj)); 2404 } 2405 } 2406 2407 /* Prevent the object from being unmapped while the bind lock is dropped. */ 2408 static void 2409 hold_object(Obj_Entry *obj) 2410 { 2411 obj->holdcount++; 2412 } 2413 2414 static void 2415 unhold_object(Obj_Entry *obj) 2416 { 2417 assert(obj->holdcount > 0); 2418 if (--obj->holdcount == 0 && obj->unholdfree) 2419 release_object(obj); 2420 } 2421 2422 static void 2423 process_z(Obj_Entry *root) 2424 { 2425 const Objlist_Entry *elm; 2426 Obj_Entry *obj; 2427 2428 /* 2429 * Walk over object DAG and process every dependent object 2430 * that is marked as DF_1_NODELETE or DF_1_GLOBAL. They need 2431 * to grow their own DAG. 2432 * 2433 * For DF_1_GLOBAL, DAG is required for symbol lookups in 2434 * symlook_global() to work. 2435 * 2436 * For DF_1_NODELETE, the DAG should have its reference upped. 2437 */ 2438 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2439 obj = elm->obj; 2440 if (obj == NULL) 2441 continue; 2442 if (obj->z_nodelete && !obj->ref_nodel) { 2443 dbg("obj %s -z nodelete", obj->path); 2444 init_dag(obj); 2445 ref_dag(obj); 2446 obj->ref_nodel = true; 2447 } 2448 if (obj->z_global && objlist_find(&list_global, obj) == NULL) { 2449 dbg("obj %s -z global", obj->path); 2450 objlist_push_tail(&list_global, obj); 2451 init_dag(obj); 2452 } 2453 } 2454 } 2455 2456 static void 2457 parse_rtld_phdr(Obj_Entry *obj) 2458 { 2459 const Elf_Phdr *ph; 2460 Elf_Addr note_start, note_end; 2461 bool first_seg; 2462 2463 first_seg = true; 2464 obj->stack_flags = PF_X | PF_R | PF_W; 2465 for (ph = obj->phdr; ph < obj->phdr + obj->phnum; ph++) { 2466 switch (ph->p_type) { 2467 case PT_LOAD: 2468 if (first_seg) { 2469 obj->vaddrbase = rtld_trunc_page(ph->p_vaddr); 2470 first_seg = false; 2471 } 2472 obj->mapsize = rtld_round_page(ph->p_vaddr + 2473 ph->p_memsz) - obj->vaddrbase; 2474 break; 2475 case PT_GNU_STACK: 2476 obj->stack_flags = ph->p_flags; 2477 break; 2478 case PT_NOTE: 2479 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; 2480 note_end = note_start + ph->p_filesz; 2481 digest_notes(obj, note_start, note_end); 2482 break; 2483 } 2484 } 2485 } 2486 2487 /* 2488 * Initialize the dynamic linker. The argument is the address at which 2489 * the dynamic linker has been mapped into memory. The primary task of 2490 * this function is to relocate the dynamic linker. 2491 */ 2492 static void 2493 init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info) 2494 { 2495 Obj_Entry objtmp; /* Temporary rtld object */ 2496 const Elf_Ehdr *ehdr; 2497 const Elf_Dyn *dyn_rpath; 2498 const Elf_Dyn *dyn_soname; 2499 const Elf_Dyn *dyn_runpath; 2500 2501 /* 2502 * Conjure up an Obj_Entry structure for the dynamic linker. 2503 * 2504 * The "path" member can't be initialized yet because string constants 2505 * cannot yet be accessed. Below we will set it correctly. 2506 */ 2507 memset(&objtmp, 0, sizeof(objtmp)); 2508 objtmp.path = NULL; 2509 objtmp.rtld = true; 2510 objtmp.mapbase = mapbase; 2511 #ifdef PIC 2512 objtmp.relocbase = mapbase; 2513 #endif 2514 2515 objtmp.dynamic = rtld_dynamic(&objtmp); 2516 digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname, &dyn_runpath); 2517 assert(objtmp.needed == NULL); 2518 assert(!objtmp.textrel); 2519 /* 2520 * Temporarily put the dynamic linker entry into the object list, so 2521 * that symbols can be found. 2522 */ 2523 relocate_objects(&objtmp, true, &objtmp, 0, NULL); 2524 2525 ehdr = (Elf_Ehdr *)mapbase; 2526 objtmp.phdr = (Elf_Phdr *)((char *)mapbase + ehdr->e_phoff); 2527 objtmp.phnum = ehdr->e_phnum; 2528 2529 /* Initialize the object list. */ 2530 TAILQ_INIT(&obj_list); 2531 2532 /* Now that non-local variables can be accesses, copy out obj_rtld. */ 2533 memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld)); 2534 2535 /* The page size is required by the dynamic memory allocator. */ 2536 init_pagesizes(aux_info); 2537 2538 if (aux_info[AT_OSRELDATE] != NULL) 2539 osreldate = aux_info[AT_OSRELDATE]->a_un.a_val; 2540 2541 digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname, dyn_runpath); 2542 2543 /* Replace the path with a dynamically allocated copy. */ 2544 obj_rtld.path = xstrdup(ld_path_rtld); 2545 2546 parse_rtld_phdr(&obj_rtld); 2547 if (obj_enforce_relro(&obj_rtld) == -1) 2548 rtld_die(); 2549 2550 r_debug.r_version = R_DEBUG_VERSION; 2551 r_debug.r_brk = r_debug_state; 2552 r_debug.r_state = RT_CONSISTENT; 2553 r_debug.r_ldbase = obj_rtld.relocbase; 2554 } 2555 2556 /* 2557 * Retrieve the array of supported page sizes. The kernel provides the page 2558 * sizes in increasing order. 2559 */ 2560 static void 2561 init_pagesizes(Elf_Auxinfo **aux_info) 2562 { 2563 static size_t psa[MAXPAGESIZES]; 2564 int mib[2]; 2565 size_t len, size; 2566 2567 if (aux_info[AT_PAGESIZES] != NULL && 2568 aux_info[AT_PAGESIZESLEN] != NULL) { 2569 size = aux_info[AT_PAGESIZESLEN]->a_un.a_val; 2570 pagesizes = aux_info[AT_PAGESIZES]->a_un.a_ptr; 2571 } else { 2572 len = 2; 2573 if (sysctlnametomib("hw.pagesizes", mib, &len) == 0) 2574 size = sizeof(psa); 2575 else { 2576 /* As a fallback, retrieve the base page size. */ 2577 size = sizeof(psa[0]); 2578 if (aux_info[AT_PAGESZ] != NULL) { 2579 psa[0] = aux_info[AT_PAGESZ]->a_un.a_val; 2580 goto psa_filled; 2581 } else { 2582 mib[0] = CTL_HW; 2583 mib[1] = HW_PAGESIZE; 2584 len = 2; 2585 } 2586 } 2587 if (sysctl(mib, len, psa, &size, NULL, 0) == -1) { 2588 _rtld_error("sysctl for hw.pagesize(s) failed"); 2589 rtld_die(); 2590 } 2591 psa_filled: 2592 pagesizes = psa; 2593 } 2594 npagesizes = size / sizeof(pagesizes[0]); 2595 /* Discard any invalid entries at the end of the array. */ 2596 while (npagesizes > 0 && pagesizes[npagesizes - 1] == 0) 2597 npagesizes--; 2598 2599 page_size = pagesizes[0]; 2600 } 2601 2602 /* 2603 * Add the init functions from a needed object list (and its recursive 2604 * needed objects) to "list". This is not used directly; it is a helper 2605 * function for initlist_add_objects(). The write lock must be held 2606 * when this function is called. 2607 */ 2608 static void 2609 initlist_add_neededs(Needed_Entry *needed, Objlist *list, Objlist *iflist) 2610 { 2611 /* Recursively process the successor needed objects. */ 2612 if (needed->next != NULL) 2613 initlist_add_neededs(needed->next, list, iflist); 2614 2615 /* Process the current needed object. */ 2616 if (needed->obj != NULL) 2617 initlist_add_objects(needed->obj, needed->obj, list, iflist); 2618 } 2619 2620 /* 2621 * Scan all of the DAGs rooted in the range of objects from "obj" to 2622 * "tail" and add their init functions to "list". This recurses over 2623 * the DAGs and ensure the proper init ordering such that each object's 2624 * needed libraries are initialized before the object itself. At the 2625 * same time, this function adds the objects to the global finalization 2626 * list "list_fini" in the opposite order. The write lock must be 2627 * held when this function is called. 2628 */ 2629 static void 2630 initlist_for_loaded_obj(Obj_Entry *obj, Obj_Entry *tail, Objlist *list) 2631 { 2632 Objlist iflist; /* initfirst objs and their needed */ 2633 Objlist_Entry *tmp; 2634 2635 objlist_init(&iflist); 2636 initlist_add_objects(obj, tail, list, &iflist); 2637 2638 STAILQ_FOREACH(tmp, &iflist, link) { 2639 Obj_Entry *tobj = tmp->obj; 2640 2641 if ((tobj->fini != 0 || tobj->fini_array != NULL) && 2642 !tobj->on_fini_list) { 2643 objlist_push_tail(&list_fini, tobj); 2644 tobj->on_fini_list = true; 2645 } 2646 } 2647 2648 /* 2649 * This might result in the same object appearing more 2650 * than once on the init list. objlist_call_init() 2651 * uses obj->init_scanned to avoid dup calls. 2652 */ 2653 STAILQ_REVERSE(&iflist, Struct_Objlist_Entry, link); 2654 STAILQ_FOREACH(tmp, &iflist, link) 2655 objlist_push_head(list, tmp->obj); 2656 2657 objlist_clear(&iflist); 2658 } 2659 2660 static void 2661 initlist_add_objects(Obj_Entry *obj, Obj_Entry *tail, Objlist *list, 2662 Objlist *iflist) 2663 { 2664 Obj_Entry *nobj; 2665 2666 if (obj->init_done) 2667 return; 2668 2669 if (obj->z_initfirst || list == NULL) { 2670 /* 2671 * Ignore obj->init_scanned. The object might indeed 2672 * already be on the init list, but due to being 2673 * needed by an initfirst object, we must put it at 2674 * the head of the init list. obj->init_done protects 2675 * against double-initialization. 2676 */ 2677 if (obj->needed != NULL) 2678 initlist_add_neededs(obj->needed, NULL, iflist); 2679 if (obj->needed_filtees != NULL) 2680 initlist_add_neededs(obj->needed_filtees, NULL, 2681 iflist); 2682 if (obj->needed_aux_filtees != NULL) 2683 initlist_add_neededs(obj->needed_aux_filtees, 2684 NULL, iflist); 2685 objlist_push_tail(iflist, obj); 2686 2687 /* Recursively process the successor objects. */ 2688 nobj = globallist_next(obj); 2689 if (nobj != NULL && obj != tail) 2690 initlist_add_objects(nobj, tail, list, iflist); 2691 } else { 2692 if (obj->init_scanned) 2693 return; 2694 obj->init_scanned = true; 2695 2696 /* Recursively process the successor objects. */ 2697 nobj = globallist_next(obj); 2698 if (nobj != NULL && obj != tail) 2699 initlist_add_objects(nobj, tail, list, iflist); 2700 2701 /* Recursively process the needed objects. */ 2702 if (obj->needed != NULL) 2703 initlist_add_neededs(obj->needed, list, iflist); 2704 if (obj->needed_filtees != NULL) 2705 initlist_add_neededs(obj->needed_filtees, list, 2706 iflist); 2707 if (obj->needed_aux_filtees != NULL) 2708 initlist_add_neededs(obj->needed_aux_filtees, list, 2709 iflist); 2710 2711 /* Add the object to the init list. */ 2712 objlist_push_tail(list, obj); 2713 2714 /* 2715 * Add the object to the global fini list in the 2716 * reverse order. 2717 */ 2718 if ((obj->fini != 0 || obj->fini_array != NULL) && 2719 !obj->on_fini_list) { 2720 objlist_push_head(&list_fini, obj); 2721 obj->on_fini_list = true; 2722 } 2723 } 2724 } 2725 2726 static void 2727 free_needed_filtees(Needed_Entry *n, RtldLockState *lockstate) 2728 { 2729 Needed_Entry *needed, *needed1; 2730 2731 for (needed = n; needed != NULL; needed = needed->next) { 2732 if (needed->obj != NULL) { 2733 dlclose_locked(needed->obj, lockstate); 2734 needed->obj = NULL; 2735 } 2736 } 2737 for (needed = n; needed != NULL; needed = needed1) { 2738 needed1 = needed->next; 2739 free(needed); 2740 } 2741 } 2742 2743 static void 2744 unload_filtees(Obj_Entry *obj, RtldLockState *lockstate) 2745 { 2746 free_needed_filtees(obj->needed_filtees, lockstate); 2747 obj->needed_filtees = NULL; 2748 free_needed_filtees(obj->needed_aux_filtees, lockstate); 2749 obj->needed_aux_filtees = NULL; 2750 obj->filtees_loaded = false; 2751 } 2752 2753 static void 2754 load_filtee1(Obj_Entry *obj, Needed_Entry *needed, int flags, 2755 RtldLockState *lockstate) 2756 { 2757 for (; needed != NULL; needed = needed->next) { 2758 needed->obj = dlopen_object(obj->strtab + needed->name, -1, obj, 2759 flags, ((ld_loadfltr || obj->z_loadfltr) ? RTLD_NOW : 2760 RTLD_LAZY) | RTLD_LOCAL, lockstate); 2761 } 2762 } 2763 2764 static void 2765 load_filtees(Obj_Entry *obj, int flags, RtldLockState *lockstate) 2766 { 2767 if (obj->filtees_loaded || obj->filtees_loading) 2768 return; 2769 lock_restart_for_upgrade(lockstate); 2770 obj->filtees_loading = true; 2771 load_filtee1(obj, obj->needed_filtees, flags, lockstate); 2772 load_filtee1(obj, obj->needed_aux_filtees, flags, lockstate); 2773 obj->filtees_loaded = true; 2774 obj->filtees_loading = false; 2775 } 2776 2777 static int 2778 process_needed(Obj_Entry *obj, Needed_Entry *needed, int flags) 2779 { 2780 Obj_Entry *obj1; 2781 2782 for (; needed != NULL; needed = needed->next) { 2783 obj1 = needed->obj = load_object(obj->strtab + needed->name, -1, 2784 obj, flags & ~RTLD_LO_NOLOAD); 2785 if (obj1 == NULL && !ld_tracing && 2786 (flags & RTLD_LO_FILTEES) == 0) 2787 return (-1); 2788 } 2789 return (0); 2790 } 2791 2792 /* 2793 * Given a shared object, traverse its list of needed objects, and load 2794 * each of them. Returns 0 on success. Generates an error message and 2795 * returns -1 on failure. 2796 */ 2797 static int 2798 load_needed_objects(Obj_Entry *first, int flags) 2799 { 2800 Obj_Entry *obj; 2801 2802 for (obj = first; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 2803 if (obj->marker) 2804 continue; 2805 if (process_needed(obj, obj->needed, flags) == -1) 2806 return (-1); 2807 } 2808 return (0); 2809 } 2810 2811 static int 2812 load_preload_objects(const char *penv, bool isfd) 2813 { 2814 Obj_Entry *obj; 2815 const char *name; 2816 size_t len; 2817 char savech, *p, *psave; 2818 int fd; 2819 static const char delim[] = " \t:;"; 2820 2821 if (penv == NULL) 2822 return (0); 2823 2824 p = psave = xstrdup(penv); 2825 p += strspn(p, delim); 2826 while (*p != '\0') { 2827 len = strcspn(p, delim); 2828 2829 savech = p[len]; 2830 p[len] = '\0'; 2831 if (isfd) { 2832 name = NULL; 2833 fd = parse_integer(p); 2834 if (fd == -1) { 2835 free(psave); 2836 return (-1); 2837 } 2838 } else { 2839 name = p; 2840 fd = -1; 2841 } 2842 2843 obj = load_object(name, fd, NULL, 0); 2844 if (obj == NULL) { 2845 free(psave); 2846 return (-1); /* XXX - cleanup */ 2847 } 2848 obj->z_interpose = true; 2849 p[len] = savech; 2850 p += len; 2851 p += strspn(p, delim); 2852 } 2853 LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL); 2854 2855 free(psave); 2856 return (0); 2857 } 2858 2859 static const char * 2860 printable_path(const char *path) 2861 { 2862 return (path == NULL ? "<unknown>" : path); 2863 } 2864 2865 /* 2866 * Load a shared object into memory, if it is not already loaded. The 2867 * object may be specified by name or by user-supplied file descriptor 2868 * fd_u. In the later case, the fd_u descriptor is not closed, but its 2869 * duplicate is. 2870 * 2871 * Returns a pointer to the Obj_Entry for the object. Returns NULL 2872 * on failure. 2873 */ 2874 static Obj_Entry * 2875 load_object(const char *name, int fd_u, const Obj_Entry *refobj, int flags) 2876 { 2877 Obj_Entry *obj; 2878 int fd; 2879 struct stat sb; 2880 char *path; 2881 2882 fd = -1; 2883 if (name != NULL) { 2884 TAILQ_FOREACH(obj, &obj_list, next) { 2885 if (obj->marker || obj->doomed) 2886 continue; 2887 if (object_match_name(obj, name)) 2888 return (obj); 2889 } 2890 2891 path = find_library(name, refobj, &fd); 2892 if (path == NULL) 2893 return (NULL); 2894 } else 2895 path = NULL; 2896 2897 if (fd >= 0) { 2898 /* 2899 * search_library_pathfds() opens a fresh file descriptor for 2900 * the library, so there is no need to dup(). 2901 */ 2902 } else if (fd_u == -1) { 2903 /* 2904 * If we didn't find a match by pathname, or the name is not 2905 * supplied, open the file and check again by device and inode. 2906 * This avoids false mismatches caused by multiple links or ".." 2907 * in pathnames. 2908 * 2909 * To avoid a race, we open the file and use fstat() rather than 2910 * using stat(). 2911 */ 2912 if ((fd = open(path, O_RDONLY | O_CLOEXEC | O_VERIFY)) == -1) { 2913 fd = try_fds_open(path, ld_library_dirs); 2914 if (fd == -1) { 2915 _rtld_error("Cannot open \"%s\"", path); 2916 free(path); 2917 return (NULL); 2918 } 2919 } 2920 } else { 2921 fd = fcntl(fd_u, F_DUPFD_CLOEXEC, 0); 2922 if (fd == -1) { 2923 _rtld_error("Cannot dup fd"); 2924 free(path); 2925 return (NULL); 2926 } 2927 } 2928 if (fstat(fd, &sb) == -1) { 2929 _rtld_error("Cannot fstat \"%s\"", printable_path(path)); 2930 close(fd); 2931 free(path); 2932 return (NULL); 2933 } 2934 TAILQ_FOREACH(obj, &obj_list, next) { 2935 if (obj->marker || obj->doomed) 2936 continue; 2937 if (obj->ino == sb.st_ino && obj->dev == sb.st_dev) 2938 break; 2939 } 2940 if (obj != NULL) { 2941 if (name != NULL) 2942 object_add_name(obj, name); 2943 free(path); 2944 close(fd); 2945 return (obj); 2946 } 2947 if (flags & RTLD_LO_NOLOAD) { 2948 free(path); 2949 close(fd); 2950 return (NULL); 2951 } 2952 2953 /* First use of this object, so we must map it in */ 2954 obj = do_load_object(fd, name, path, &sb, flags); 2955 if (obj == NULL) 2956 free(path); 2957 close(fd); 2958 2959 return (obj); 2960 } 2961 2962 static Obj_Entry * 2963 do_load_object(int fd, const char *name, char *path, struct stat *sbp, 2964 int flags) 2965 { 2966 Obj_Entry *obj; 2967 struct statfs fs; 2968 2969 /* 2970 * First, make sure that environment variables haven't been 2971 * used to circumvent the noexec flag on a filesystem. 2972 * We ignore fstatfs(2) failures, since fd might reference 2973 * not a file, e.g. shmfd. 2974 */ 2975 if (dangerous_ld_env && fstatfs(fd, &fs) == 0 && 2976 (fs.f_flags & MNT_NOEXEC) != 0) { 2977 _rtld_error("Cannot execute objects on %s", fs.f_mntonname); 2978 return (NULL); 2979 } 2980 2981 dbg("loading \"%s\"", printable_path(path)); 2982 obj = map_object(fd, printable_path(path), sbp, false); 2983 if (obj == NULL) 2984 return (NULL); 2985 2986 /* 2987 * If DT_SONAME is present in the object, digest_dynamic2 already 2988 * added it to the object names. 2989 */ 2990 if (name != NULL) 2991 object_add_name(obj, name); 2992 obj->path = path; 2993 if (!digest_dynamic(obj, 0)) 2994 goto errp; 2995 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", obj->path, 2996 obj->valid_hash_sysv, obj->valid_hash_gnu, obj->dynsymcount); 2997 if (obj->z_pie && (flags & RTLD_LO_TRACE) == 0) { 2998 dbg("refusing to load PIE executable \"%s\"", obj->path); 2999 _rtld_error("Cannot load PIE binary %s as DSO", obj->path); 3000 goto errp; 3001 } 3002 if (obj->z_noopen && 3003 (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) == RTLD_LO_DLOPEN) { 3004 dbg("refusing to load non-loadable \"%s\"", obj->path); 3005 _rtld_error("Cannot dlopen non-loadable %s", obj->path); 3006 goto errp; 3007 } 3008 3009 obj->dlopened = (flags & RTLD_LO_DLOPEN) != 0; 3010 TAILQ_INSERT_TAIL(&obj_list, obj, next); 3011 obj_count++; 3012 obj_loads++; 3013 linkmap_add(obj); /* for GDB & dlinfo() */ 3014 max_stack_flags |= obj->stack_flags; 3015 3016 dbg(" %p .. %p: %s", obj->mapbase, obj->mapbase + obj->mapsize - 1, 3017 obj->path); 3018 if (obj->textrel) 3019 dbg(" WARNING: %s has impure text", obj->path); 3020 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 3021 obj->path); 3022 3023 return (obj); 3024 3025 errp: 3026 munmap(obj->mapbase, obj->mapsize); 3027 obj_free(obj); 3028 return (NULL); 3029 } 3030 3031 static int 3032 load_kpreload(const void *addr) 3033 { 3034 Obj_Entry *obj; 3035 const Elf_Ehdr *ehdr; 3036 const Elf_Phdr *phdr, *phlimit, *phdyn, *seg0, *segn; 3037 static const char kname[] = "[vdso]"; 3038 3039 ehdr = addr; 3040 if (!check_elf_headers(ehdr, "kpreload")) 3041 return (-1); 3042 obj = obj_new(); 3043 phdr = (const Elf_Phdr *)((const char *)addr + ehdr->e_phoff); 3044 obj->phdr = phdr; 3045 obj->phnum = ehdr->e_phnum; 3046 phlimit = phdr + ehdr->e_phnum; 3047 seg0 = segn = NULL; 3048 3049 for (; phdr < phlimit; phdr++) { 3050 switch (phdr->p_type) { 3051 case PT_DYNAMIC: 3052 phdyn = phdr; 3053 break; 3054 case PT_GNU_STACK: 3055 /* Absense of PT_GNU_STACK implies stack_flags == 0. */ 3056 obj->stack_flags = phdr->p_flags; 3057 break; 3058 case PT_LOAD: 3059 if (seg0 == NULL || seg0->p_vaddr > phdr->p_vaddr) 3060 seg0 = phdr; 3061 if (segn == NULL || 3062 segn->p_vaddr + segn->p_memsz < 3063 phdr->p_vaddr + phdr->p_memsz) 3064 segn = phdr; 3065 break; 3066 } 3067 } 3068 3069 obj->mapbase = __DECONST(caddr_t, addr); 3070 obj->mapsize = segn->p_vaddr + segn->p_memsz; 3071 obj->vaddrbase = 0; 3072 obj->relocbase = obj->mapbase; 3073 3074 object_add_name(obj, kname); 3075 obj->path = xstrdup(kname); 3076 obj->dynamic = (const Elf_Dyn *)(obj->relocbase + phdyn->p_vaddr); 3077 3078 if (!digest_dynamic(obj, 0)) { 3079 obj_free(obj); 3080 return (-1); 3081 } 3082 3083 /* 3084 * We assume that kernel-preloaded object does not need 3085 * relocation. It is currently written into read-only page, 3086 * handling relocations would mean we need to allocate at 3087 * least one additional page per AS. 3088 */ 3089 dbg("%s mapbase %p phdrs %p PT_LOAD phdr %p vaddr %p dynamic %p", 3090 obj->path, obj->mapbase, obj->phdr, seg0, 3091 obj->relocbase + seg0->p_vaddr, obj->dynamic); 3092 3093 TAILQ_INSERT_TAIL(&obj_list, obj, next); 3094 obj_count++; 3095 obj_loads++; 3096 linkmap_add(obj); /* for GDB & dlinfo() */ 3097 max_stack_flags |= obj->stack_flags; 3098 3099 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 3100 obj->path); 3101 return (0); 3102 } 3103 3104 Obj_Entry * 3105 obj_from_addr(const void *addr) 3106 { 3107 Obj_Entry *obj; 3108 3109 TAILQ_FOREACH(obj, &obj_list, next) { 3110 if (obj->marker) 3111 continue; 3112 if (addr < (void *)obj->mapbase) 3113 continue; 3114 if (addr < (void *)(obj->mapbase + obj->mapsize)) 3115 return obj; 3116 } 3117 return (NULL); 3118 } 3119 3120 static void 3121 preinit_main(void) 3122 { 3123 uintptr_t *preinit_addr; 3124 int index; 3125 3126 preinit_addr = obj_main->preinit_array; 3127 if (preinit_addr == NULL) 3128 return; 3129 3130 for (index = 0; index < obj_main->preinit_array_num; index++) { 3131 if (preinit_addr[index] != 0 && preinit_addr[index] != 1) { 3132 dbg("calling preinit function for %s at %p", 3133 obj_main->path, (void *)preinit_addr[index]); 3134 LD_UTRACE(UTRACE_INIT_CALL, obj_main, 3135 (void *)preinit_addr[index], 0, 0, obj_main->path); 3136 call_init_pointer(obj_main, preinit_addr[index]); 3137 } 3138 } 3139 } 3140 3141 /* 3142 * Call the finalization functions for each of the objects in "list" 3143 * belonging to the DAG of "root" and referenced once. If NULL "root" 3144 * is specified, every finalization function will be called regardless 3145 * of the reference count and the list elements won't be freed. All of 3146 * the objects are expected to have non-NULL fini functions. 3147 */ 3148 static void 3149 objlist_call_fini(Objlist *list, Obj_Entry *root, RtldLockState *lockstate) 3150 { 3151 Objlist_Entry *elm; 3152 struct dlerror_save *saved_msg; 3153 uintptr_t *fini_addr; 3154 int index; 3155 3156 assert(root == NULL || root->refcount == 1); 3157 3158 if (root != NULL) 3159 root->doomed = true; 3160 3161 /* 3162 * Preserve the current error message since a fini function might 3163 * call into the dynamic linker and overwrite it. 3164 */ 3165 saved_msg = errmsg_save(); 3166 do { 3167 STAILQ_FOREACH(elm, list, link) { 3168 if (root != NULL && 3169 (elm->obj->refcount != 1 || 3170 objlist_find(&root->dagmembers, elm->obj) == 3171 NULL)) 3172 continue; 3173 /* Remove object from fini list to prevent recursive 3174 * invocation. */ 3175 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 3176 /* Ensure that new references cannot be acquired. */ 3177 elm->obj->doomed = true; 3178 3179 hold_object(elm->obj); 3180 lock_release(rtld_bind_lock, lockstate); 3181 /* 3182 * It is legal to have both DT_FINI and DT_FINI_ARRAY 3183 * defined. When this happens, DT_FINI_ARRAY is 3184 * processed first. 3185 */ 3186 fini_addr = elm->obj->fini_array; 3187 if (fini_addr != NULL && elm->obj->fini_array_num > 0) { 3188 for (index = elm->obj->fini_array_num - 1; 3189 index >= 0; index--) { 3190 if (fini_addr[index] != 0 && 3191 fini_addr[index] != 1 && 3192 fini_addr[index] != (Elf_Addr)-1) { 3193 dbg("calling fini function for %s at %p", 3194 elm->obj->path, 3195 (void *)fini_addr[index]); 3196 LD_UTRACE(UTRACE_FINI_CALL, 3197 elm->obj, 3198 (void *)fini_addr[index], 0, 3199 0, elm->obj->path); 3200 call_initfini_pointer(elm->obj, 3201 fini_addr[index]); 3202 } 3203 } 3204 } 3205 if (elm->obj->fini != 0) { 3206 dbg("calling fini function for %s at %p", 3207 elm->obj->path, (void *)elm->obj->fini); 3208 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, 3209 (void *)elm->obj->fini, 0, 0, 3210 elm->obj->path); 3211 call_initfini_pointer(elm->obj, elm->obj->fini); 3212 } 3213 wlock_acquire(rtld_bind_lock, lockstate); 3214 unhold_object(elm->obj); 3215 /* No need to free anything if process is going down. */ 3216 if (root != NULL) 3217 free(elm); 3218 /* 3219 * We must restart the list traversal after every fini 3220 * call because a dlclose() call from the fini function 3221 * or from another thread might have modified the 3222 * reference counts. 3223 */ 3224 break; 3225 } 3226 } while (elm != NULL); 3227 errmsg_restore(saved_msg); 3228 } 3229 3230 /* 3231 * Call the initialization functions for each of the objects in 3232 * "list". All of the objects are expected to have non-NULL init 3233 * functions. 3234 */ 3235 static void 3236 objlist_call_init(Objlist *list, RtldLockState *lockstate) 3237 { 3238 Objlist_Entry *elm; 3239 Obj_Entry *obj; 3240 struct dlerror_save *saved_msg; 3241 uintptr_t *init_addr; 3242 void (*reg)(void (*)(void)); 3243 int index; 3244 3245 /* 3246 * Clean init_scanned flag so that objects can be rechecked and 3247 * possibly initialized earlier if any of vectors called below 3248 * cause the change by using dlopen. 3249 */ 3250 TAILQ_FOREACH(obj, &obj_list, next) { 3251 if (obj->marker) 3252 continue; 3253 obj->init_scanned = false; 3254 } 3255 3256 /* 3257 * Preserve the current error message since an init function might 3258 * call into the dynamic linker and overwrite it. 3259 */ 3260 saved_msg = errmsg_save(); 3261 STAILQ_FOREACH(elm, list, link) { 3262 if (elm->obj->init_done) /* Initialized early. */ 3263 continue; 3264 /* 3265 * Race: other thread might try to use this object before 3266 * current one completes the initialization. Not much can be 3267 * done here without better locking. 3268 */ 3269 elm->obj->init_done = true; 3270 hold_object(elm->obj); 3271 reg = NULL; 3272 if (elm->obj == obj_main && obj_main->crt_no_init) { 3273 reg = (void (*)(void (*)(void))) 3274 get_program_var_addr("__libc_atexit", lockstate); 3275 } 3276 lock_release(rtld_bind_lock, lockstate); 3277 if (reg != NULL) { 3278 reg(rtld_exit); 3279 rtld_exit_ptr = rtld_nop_exit; 3280 } 3281 3282 /* 3283 * It is legal to have both DT_INIT and DT_INIT_ARRAY defined. 3284 * When this happens, DT_INIT is processed first. 3285 */ 3286 if (elm->obj->init != 0) { 3287 dbg("calling init function for %s at %p", 3288 elm->obj->path, (void *)elm->obj->init); 3289 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, 3290 (void *)elm->obj->init, 0, 0, elm->obj->path); 3291 call_init_pointer(elm->obj, elm->obj->init); 3292 } 3293 init_addr = elm->obj->init_array; 3294 if (init_addr != NULL) { 3295 for (index = 0; index < elm->obj->init_array_num; 3296 index++) { 3297 if (init_addr[index] != 0 && 3298 init_addr[index] != 1 && 3299 init_addr[index] != (Elf_Addr)-1) { 3300 dbg("calling init function for %s at %p", 3301 elm->obj->path, 3302 (void *)init_addr[index]); 3303 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, 3304 (void *)init_addr[index], 0, 0, 3305 elm->obj->path); 3306 call_init_pointer(elm->obj, 3307 init_addr[index]); 3308 } 3309 } 3310 } 3311 wlock_acquire(rtld_bind_lock, lockstate); 3312 unhold_object(elm->obj); 3313 } 3314 errmsg_restore(saved_msg); 3315 } 3316 3317 static void 3318 objlist_clear(Objlist *list) 3319 { 3320 Objlist_Entry *elm; 3321 3322 while (!STAILQ_EMPTY(list)) { 3323 elm = STAILQ_FIRST(list); 3324 STAILQ_REMOVE_HEAD(list, link); 3325 free(elm); 3326 } 3327 } 3328 3329 static Objlist_Entry * 3330 objlist_find(Objlist *list, const Obj_Entry *obj) 3331 { 3332 Objlist_Entry *elm; 3333 3334 STAILQ_FOREACH(elm, list, link) 3335 if (elm->obj == obj) 3336 return elm; 3337 return (NULL); 3338 } 3339 3340 static void 3341 objlist_init(Objlist *list) 3342 { 3343 STAILQ_INIT(list); 3344 } 3345 3346 static void 3347 objlist_push_head(Objlist *list, Obj_Entry *obj) 3348 { 3349 Objlist_Entry *elm; 3350 3351 elm = NEW(Objlist_Entry); 3352 elm->obj = obj; 3353 STAILQ_INSERT_HEAD(list, elm, link); 3354 } 3355 3356 static void 3357 objlist_push_tail(Objlist *list, Obj_Entry *obj) 3358 { 3359 Objlist_Entry *elm; 3360 3361 elm = NEW(Objlist_Entry); 3362 elm->obj = obj; 3363 STAILQ_INSERT_TAIL(list, elm, link); 3364 } 3365 3366 static void 3367 objlist_put_after(Objlist *list, Obj_Entry *listobj, Obj_Entry *obj) 3368 { 3369 Objlist_Entry *elm, *listelm; 3370 3371 STAILQ_FOREACH(listelm, list, link) { 3372 if (listelm->obj == listobj) 3373 break; 3374 } 3375 elm = NEW(Objlist_Entry); 3376 elm->obj = obj; 3377 if (listelm != NULL) 3378 STAILQ_INSERT_AFTER(list, listelm, elm, link); 3379 else 3380 STAILQ_INSERT_TAIL(list, elm, link); 3381 } 3382 3383 static void 3384 objlist_remove(Objlist *list, Obj_Entry *obj) 3385 { 3386 Objlist_Entry *elm; 3387 3388 if ((elm = objlist_find(list, obj)) != NULL) { 3389 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 3390 free(elm); 3391 } 3392 } 3393 3394 /* 3395 * Relocate dag rooted in the specified object. 3396 * Returns 0 on success, or -1 on failure. 3397 */ 3398 3399 static int 3400 relocate_object_dag(Obj_Entry *root, bool bind_now, Obj_Entry *rtldobj, 3401 int flags, RtldLockState *lockstate) 3402 { 3403 Objlist_Entry *elm; 3404 int error; 3405 3406 error = 0; 3407 STAILQ_FOREACH(elm, &root->dagmembers, link) { 3408 error = relocate_object(elm->obj, bind_now, rtldobj, flags, 3409 lockstate); 3410 if (error == -1) 3411 break; 3412 } 3413 return (error); 3414 } 3415 3416 /* 3417 * Prepare for, or clean after, relocating an object marked with 3418 * DT_TEXTREL or DF_TEXTREL. Before relocating, all read-only 3419 * segments are remapped read-write. After relocations are done, the 3420 * segment's permissions are returned back to the modes specified in 3421 * the phdrs. If any relocation happened, or always for wired 3422 * program, COW is triggered. 3423 */ 3424 static int 3425 reloc_textrel_prot(Obj_Entry *obj, bool before) 3426 { 3427 const Elf_Phdr *ph; 3428 void *base; 3429 size_t sz; 3430 int prot; 3431 3432 for (ph = obj->phdr; ph < obj->phdr + obj->phnum; ph++) { 3433 if (ph->p_type != PT_LOAD || (ph->p_flags & PF_W) != 0) 3434 continue; 3435 base = obj->relocbase + rtld_trunc_page(ph->p_vaddr); 3436 sz = rtld_round_page(ph->p_vaddr + ph->p_filesz) - 3437 rtld_trunc_page(ph->p_vaddr); 3438 prot = before ? (PROT_READ | PROT_WRITE) : 3439 convert_prot(ph->p_flags); 3440 if (mprotect(base, sz, prot) == -1) { 3441 _rtld_error("%s: Cannot write-%sable text segment: %s", 3442 obj->path, before ? "en" : "dis", 3443 rtld_strerror(errno)); 3444 return (-1); 3445 } 3446 } 3447 return (0); 3448 } 3449 3450 /* Process RELR relative relocations. */ 3451 static void 3452 reloc_relr(Obj_Entry *obj) 3453 { 3454 const Elf_Relr *relr, *relrlim; 3455 Elf_Addr *where; 3456 3457 relrlim = (const Elf_Relr *)((const char *)obj->relr + obj->relrsize); 3458 for (relr = obj->relr; relr < relrlim; relr++) { 3459 Elf_Relr entry = *relr; 3460 3461 if ((entry & 1) == 0) { 3462 where = (Elf_Addr *)(obj->relocbase + entry); 3463 *where++ += (Elf_Addr)obj->relocbase; 3464 } else { 3465 for (long i = 0; (entry >>= 1) != 0; i++) 3466 if ((entry & 1) != 0) 3467 where[i] += (Elf_Addr)obj->relocbase; 3468 where += CHAR_BIT * sizeof(Elf_Relr) - 1; 3469 } 3470 } 3471 } 3472 3473 /* 3474 * Relocate single object. 3475 * Returns 0 on success, or -1 on failure. 3476 */ 3477 static int 3478 relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, int flags, 3479 RtldLockState *lockstate) 3480 { 3481 if (obj->relocated) 3482 return (0); 3483 obj->relocated = true; 3484 if (obj != rtldobj) 3485 dbg("relocating \"%s\"", obj->path); 3486 3487 if (obj->symtab == NULL || obj->strtab == NULL || 3488 !(obj->valid_hash_sysv || obj->valid_hash_gnu)) 3489 dbg("object %s has no run-time symbol table", obj->path); 3490 3491 /* There are relocations to the write-protected text segment. */ 3492 if (obj->textrel && reloc_textrel_prot(obj, true) != 0) 3493 return (-1); 3494 3495 /* Process the non-PLT non-IFUNC relocations. */ 3496 if (reloc_non_plt(obj, rtldobj, flags, lockstate)) 3497 return (-1); 3498 reloc_relr(obj); 3499 3500 /* Re-protected the text segment. */ 3501 if (obj->textrel && reloc_textrel_prot(obj, false) != 0) 3502 return (-1); 3503 3504 /* Set the special PLT or GOT entries. */ 3505 init_pltgot(obj); 3506 3507 /* Process the PLT relocations. */ 3508 if (reloc_plt(obj, flags, lockstate) == -1) 3509 return (-1); 3510 /* Relocate the jump slots if we are doing immediate binding. */ 3511 if ((obj->bind_now || bind_now) && 3512 reloc_jmpslots(obj, flags, lockstate) == -1) 3513 return (-1); 3514 3515 if (obj != rtldobj && !obj->mainprog && obj_enforce_relro(obj) == -1) 3516 return (-1); 3517 3518 /* 3519 * Set up the magic number and version in the Obj_Entry. These 3520 * were checked in the crt1.o from the original ElfKit, so we 3521 * set them for backward compatibility. 3522 */ 3523 obj->magic = RTLD_MAGIC; 3524 obj->version = RTLD_VERSION; 3525 3526 return (0); 3527 } 3528 3529 /* 3530 * Relocate newly-loaded shared objects. The argument is a pointer to 3531 * the Obj_Entry for the first such object. All objects from the first 3532 * to the end of the list of objects are relocated. Returns 0 on success, 3533 * or -1 on failure. 3534 */ 3535 static int 3536 relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj, int flags, 3537 RtldLockState *lockstate) 3538 { 3539 Obj_Entry *obj; 3540 int error; 3541 3542 for (error = 0, obj = first; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 3543 if (obj->marker) 3544 continue; 3545 error = relocate_object(obj, bind_now, rtldobj, flags, 3546 lockstate); 3547 if (error == -1) 3548 break; 3549 } 3550 return (error); 3551 } 3552 3553 /* 3554 * The handling of R_MACHINE_IRELATIVE relocations and jumpslots 3555 * referencing STT_GNU_IFUNC symbols is postponed till the other 3556 * relocations are done. The indirect functions specified as 3557 * ifunc are allowed to call other symbols, so we need to have 3558 * objects relocated before asking for resolution from indirects. 3559 * 3560 * The R_MACHINE_IRELATIVE slots are resolved in greedy fashion, 3561 * instead of the usual lazy handling of PLT slots. It is 3562 * consistent with how GNU does it. 3563 */ 3564 static int 3565 resolve_object_ifunc(Obj_Entry *obj, bool bind_now, int flags, 3566 RtldLockState *lockstate) 3567 { 3568 if (obj->ifuncs_resolved) 3569 return (0); 3570 obj->ifuncs_resolved = true; 3571 if (!obj->irelative && !obj->irelative_nonplt && 3572 !((obj->bind_now || bind_now) && obj->gnu_ifunc) && 3573 !obj->non_plt_gnu_ifunc) 3574 return (0); 3575 if (obj_disable_relro(obj) == -1 || 3576 (obj->irelative && reloc_iresolve(obj, lockstate) == -1) || 3577 (obj->irelative_nonplt && 3578 reloc_iresolve_nonplt(obj, lockstate) == -1) || 3579 ((obj->bind_now || bind_now) && obj->gnu_ifunc && 3580 reloc_gnu_ifunc(obj, flags, lockstate) == -1) || 3581 (obj->non_plt_gnu_ifunc && 3582 reloc_non_plt(obj, &obj_rtld, flags | SYMLOOK_IFUNC, 3583 lockstate) == -1) || 3584 obj_enforce_relro(obj) == -1) 3585 return (-1); 3586 return (0); 3587 } 3588 3589 static int 3590 initlist_objects_ifunc(Objlist *list, bool bind_now, int flags, 3591 RtldLockState *lockstate) 3592 { 3593 Objlist_Entry *elm; 3594 Obj_Entry *obj; 3595 3596 STAILQ_FOREACH(elm, list, link) { 3597 obj = elm->obj; 3598 if (obj->marker) 3599 continue; 3600 if (resolve_object_ifunc(obj, bind_now, flags, lockstate) == -1) 3601 return (-1); 3602 } 3603 return (0); 3604 } 3605 3606 /* 3607 * Cleanup procedure. It will be called (by the atexit mechanism) just 3608 * before the process exits. 3609 */ 3610 static void 3611 rtld_exit(void) 3612 { 3613 RtldLockState lockstate; 3614 3615 wlock_acquire(rtld_bind_lock, &lockstate); 3616 dbg("rtld_exit()"); 3617 objlist_call_fini(&list_fini, NULL, &lockstate); 3618 /* No need to remove the items from the list, since we are exiting. */ 3619 if (!libmap_disable) 3620 lm_fini(); 3621 lock_release(rtld_bind_lock, &lockstate); 3622 } 3623 3624 static void 3625 rtld_nop_exit(void) 3626 { 3627 } 3628 3629 /* 3630 * Parse string of the format '#number/name", where number must be a 3631 * decimal number of the opened file descriptor listed in 3632 * LD_LIBRARY_PATH_FDS. If successful, tries to open dso name under 3633 * dirfd number and returns resulting fd. 3634 * On any error, returns -1. 3635 */ 3636 static int 3637 try_fds_open(const char *name, const char *path) 3638 { 3639 const char *n; 3640 char *envcopy, *fdstr, *last_token, *ncopy; 3641 size_t len; 3642 int fd, dirfd, dirfd_path; 3643 3644 if (!trust || name[0] != '#' || path == NULL) 3645 return (-1); 3646 3647 name++; 3648 n = strchr(name, '/'); 3649 if (n == NULL) 3650 return (-1); 3651 len = n - name; 3652 ncopy = xmalloc(len + 1); 3653 memcpy(ncopy, name, len); 3654 ncopy[len] = '\0'; 3655 dirfd = parse_integer(ncopy); 3656 free(ncopy); 3657 if (dirfd == -1) 3658 return (-1); 3659 3660 envcopy = xstrdup(path); 3661 dirfd_path = -1; 3662 for (fdstr = strtok_r(envcopy, ":", &last_token); fdstr != NULL; 3663 fdstr = strtok_r(NULL, ":", &last_token)) { 3664 dirfd_path = parse_integer(fdstr); 3665 if (dirfd_path == dirfd) 3666 break; 3667 } 3668 free(envcopy); 3669 if (dirfd_path != dirfd) 3670 return (-1); 3671 3672 fd = __sys_openat(dirfd, n + 1, O_RDONLY | O_CLOEXEC | O_VERIFY); 3673 return (fd); 3674 } 3675 3676 /* 3677 * Iterate over a search path, translate each element, and invoke the 3678 * callback on the result. 3679 */ 3680 static void * 3681 path_enumerate(const char *path, path_enum_proc callback, 3682 const char *refobj_path, void *arg) 3683 { 3684 const char *trans; 3685 if (path == NULL) 3686 return (NULL); 3687 3688 path += strspn(path, ":;"); 3689 while (*path != '\0') { 3690 size_t len; 3691 char *res; 3692 3693 len = strcspn(path, ":;"); 3694 trans = lm_findn(refobj_path, path, len); 3695 if (trans) 3696 res = callback(trans, strlen(trans), arg); 3697 else 3698 res = callback(path, len, arg); 3699 3700 if (res != NULL) 3701 return (res); 3702 3703 path += len; 3704 path += strspn(path, ":;"); 3705 } 3706 3707 return (NULL); 3708 } 3709 3710 struct try_library_args { 3711 const char *name; 3712 size_t namelen; 3713 char *buffer; 3714 size_t buflen; 3715 int fd; 3716 }; 3717 3718 static void * 3719 try_library_path(const char *dir, size_t dirlen, void *param) 3720 { 3721 struct try_library_args *arg; 3722 int fd; 3723 3724 arg = param; 3725 if (*dir == '/' || trust) { 3726 char *pathname; 3727 3728 if (dirlen + 1 + arg->namelen + 1 > arg->buflen) 3729 return (NULL); 3730 3731 pathname = arg->buffer; 3732 strncpy(pathname, dir, dirlen); 3733 pathname[dirlen] = '/'; 3734 strcpy(pathname + dirlen + 1, arg->name); 3735 3736 dbg(" Trying \"%s\"", pathname); 3737 fd = open(pathname, O_RDONLY | O_CLOEXEC | O_VERIFY); 3738 if (fd >= 0) { 3739 dbg(" Opened \"%s\", fd %d", pathname, fd); 3740 pathname = xmalloc(dirlen + 1 + arg->namelen + 1); 3741 strcpy(pathname, arg->buffer); 3742 arg->fd = fd; 3743 return (pathname); 3744 } else { 3745 dbg(" Failed to open \"%s\": %s", pathname, 3746 rtld_strerror(errno)); 3747 } 3748 } 3749 return (NULL); 3750 } 3751 3752 static char * 3753 search_library_path(const char *name, const char *path, const char *refobj_path, 3754 int *fdp) 3755 { 3756 char *p; 3757 struct try_library_args arg; 3758 3759 if (path == NULL) 3760 return (NULL); 3761 3762 arg.name = name; 3763 arg.namelen = strlen(name); 3764 arg.buffer = xmalloc(PATH_MAX); 3765 arg.buflen = PATH_MAX; 3766 arg.fd = -1; 3767 3768 p = path_enumerate(path, try_library_path, refobj_path, &arg); 3769 *fdp = arg.fd; 3770 3771 free(arg.buffer); 3772 3773 return (p); 3774 } 3775 3776 /* 3777 * Finds the library with the given name using the directory descriptors 3778 * listed in the LD_LIBRARY_PATH_FDS environment variable. 3779 * 3780 * Returns a freshly-opened close-on-exec file descriptor for the library, 3781 * or -1 if the library cannot be found. 3782 */ 3783 static char * 3784 search_library_pathfds(const char *name, const char *path, int *fdp) 3785 { 3786 char *envcopy, *fdstr, *found, *last_token; 3787 size_t len; 3788 int dirfd, fd; 3789 3790 dbg("%s('%s', '%s', fdp)", __func__, name, path); 3791 3792 /* Don't load from user-specified libdirs into setuid binaries. */ 3793 if (!trust) 3794 return (NULL); 3795 3796 /* We can't do anything if LD_LIBRARY_PATH_FDS isn't set. */ 3797 if (path == NULL) 3798 return (NULL); 3799 3800 /* LD_LIBRARY_PATH_FDS only works with relative paths. */ 3801 if (name[0] == '/') { 3802 dbg("Absolute path (%s) passed to %s", name, __func__); 3803 return (NULL); 3804 } 3805 3806 /* 3807 * Use strtok_r() to walk the FD:FD:FD list. This requires a local 3808 * copy of the path, as strtok_r rewrites separator tokens 3809 * with '\0'. 3810 */ 3811 found = NULL; 3812 envcopy = xstrdup(path); 3813 for (fdstr = strtok_r(envcopy, ":", &last_token); fdstr != NULL; 3814 fdstr = strtok_r(NULL, ":", &last_token)) { 3815 dirfd = parse_integer(fdstr); 3816 if (dirfd < 0) { 3817 _rtld_error("failed to parse directory FD: '%s'", 3818 fdstr); 3819 break; 3820 } 3821 fd = __sys_openat(dirfd, name, O_RDONLY | O_CLOEXEC | O_VERIFY); 3822 if (fd >= 0) { 3823 *fdp = fd; 3824 len = strlen(fdstr) + strlen(name) + 3; 3825 found = xmalloc(len); 3826 if (rtld_snprintf(found, len, "#%d/%s", dirfd, name) < 3827 0) { 3828 _rtld_error("error generating '%d/%s'", dirfd, 3829 name); 3830 rtld_die(); 3831 } 3832 dbg("open('%s') => %d", found, fd); 3833 break; 3834 } 3835 } 3836 free(envcopy); 3837 3838 return (found); 3839 } 3840 3841 int 3842 dlclose(void *handle) 3843 { 3844 RtldLockState lockstate; 3845 int error; 3846 3847 wlock_acquire(rtld_bind_lock, &lockstate); 3848 error = dlclose_locked(handle, &lockstate); 3849 lock_release(rtld_bind_lock, &lockstate); 3850 return (error); 3851 } 3852 3853 static int 3854 dlclose_locked(void *handle, RtldLockState *lockstate) 3855 { 3856 Obj_Entry *root; 3857 3858 root = dlcheck(handle); 3859 if (root == NULL) 3860 return (-1); 3861 LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount, 3862 root->path); 3863 3864 /* Unreference the object and its dependencies. */ 3865 root->dl_refcount--; 3866 3867 if (root->refcount == 1) { 3868 /* 3869 * The object will be no longer referenced, so we must unload 3870 * it. First, call the fini functions. 3871 */ 3872 objlist_call_fini(&list_fini, root, lockstate); 3873 3874 unref_dag(root); 3875 3876 /* Finish cleaning up the newly-unreferenced objects. */ 3877 GDB_STATE(RT_DELETE, &root->linkmap); 3878 unload_object(root, lockstate); 3879 GDB_STATE(RT_CONSISTENT, NULL); 3880 } else 3881 unref_dag(root); 3882 3883 LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL); 3884 return (0); 3885 } 3886 3887 char * 3888 dlerror(void) 3889 { 3890 if (*(lockinfo.dlerror_seen()) != 0) 3891 return (NULL); 3892 *lockinfo.dlerror_seen() = 1; 3893 return (lockinfo.dlerror_loc()); 3894 } 3895 3896 /* 3897 * This function is deprecated and has no effect. 3898 */ 3899 void 3900 dllockinit(void *context, void *(*_lock_create)(void *context)__unused, 3901 void (*_rlock_acquire)(void *lock) __unused, 3902 void (*_wlock_acquire)(void *lock) __unused, 3903 void (*_lock_release)(void *lock) __unused, 3904 void (*_lock_destroy)(void *lock) __unused, 3905 void (*context_destroy)(void *context)) 3906 { 3907 static void *cur_context; 3908 static void (*cur_context_destroy)(void *); 3909 3910 /* Just destroy the context from the previous call, if necessary. */ 3911 if (cur_context_destroy != NULL) 3912 cur_context_destroy(cur_context); 3913 cur_context = context; 3914 cur_context_destroy = context_destroy; 3915 } 3916 3917 void * 3918 dlopen(const char *name, int mode) 3919 { 3920 return (rtld_dlopen(name, -1, mode)); 3921 } 3922 3923 void * 3924 fdlopen(int fd, int mode) 3925 { 3926 return (rtld_dlopen(NULL, fd, mode)); 3927 } 3928 3929 static void * 3930 rtld_dlopen(const char *name, int fd, int mode) 3931 { 3932 RtldLockState lockstate; 3933 int lo_flags; 3934 3935 LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name); 3936 ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1"; 3937 if (ld_tracing != NULL) { 3938 rlock_acquire(rtld_bind_lock, &lockstate); 3939 if (sigsetjmp(lockstate.env, 0) != 0) 3940 lock_upgrade(rtld_bind_lock, &lockstate); 3941 environ = __DECONST(char **, 3942 *get_program_var_addr("environ", &lockstate)); 3943 lock_release(rtld_bind_lock, &lockstate); 3944 } 3945 lo_flags = RTLD_LO_DLOPEN; 3946 if (mode & RTLD_NODELETE) 3947 lo_flags |= RTLD_LO_NODELETE; 3948 if (mode & RTLD_NOLOAD) 3949 lo_flags |= RTLD_LO_NOLOAD; 3950 if (mode & RTLD_DEEPBIND) 3951 lo_flags |= RTLD_LO_DEEPBIND; 3952 if (ld_tracing != NULL) 3953 lo_flags |= RTLD_LO_TRACE | RTLD_LO_IGNSTLS; 3954 3955 return (dlopen_object(name, fd, obj_main, lo_flags, 3956 mode & (RTLD_MODEMASK | RTLD_GLOBAL), NULL)); 3957 } 3958 3959 static void 3960 dlopen_cleanup(Obj_Entry *obj, RtldLockState *lockstate) 3961 { 3962 obj->dl_refcount--; 3963 unref_dag(obj); 3964 if (obj->refcount == 0) 3965 unload_object(obj, lockstate); 3966 } 3967 3968 static Obj_Entry * 3969 dlopen_object(const char *name, int fd, Obj_Entry *refobj, int lo_flags, 3970 int mode, RtldLockState *lockstate) 3971 { 3972 Obj_Entry *obj; 3973 Objlist initlist; 3974 RtldLockState mlockstate; 3975 int result; 3976 3977 dbg( 3978 "dlopen_object name \"%s\" fd %d refobj \"%s\" lo_flags %#x mode %#x", 3979 name != NULL ? name : "<null>", fd, 3980 refobj == NULL ? "<null>" : refobj->path, lo_flags, mode); 3981 objlist_init(&initlist); 3982 3983 if (lockstate == NULL && !(lo_flags & RTLD_LO_EARLY)) { 3984 wlock_acquire(rtld_bind_lock, &mlockstate); 3985 lockstate = &mlockstate; 3986 } 3987 GDB_STATE(RT_ADD, NULL); 3988 3989 obj = NULL; 3990 if (name == NULL && fd == -1) { 3991 obj = obj_main; 3992 obj->refcount++; 3993 } else { 3994 obj = load_object(name, fd, refobj, lo_flags); 3995 } 3996 3997 if (obj != NULL) { 3998 obj->dl_refcount++; 3999 if ((mode & RTLD_GLOBAL) != 0 && 4000 objlist_find(&list_global, obj) == NULL) 4001 objlist_push_tail(&list_global, obj); 4002 4003 if (!obj->init_done) { 4004 /* We loaded something new and have to init something. 4005 */ 4006 if ((lo_flags & RTLD_LO_DEEPBIND) != 0) 4007 obj->deepbind = true; 4008 result = 0; 4009 if ((lo_flags & (RTLD_LO_EARLY | 4010 RTLD_LO_IGNSTLS)) == 0 && 4011 obj->static_tls && !allocate_tls_offset(obj)) { 4012 _rtld_error( 4013 "%s: No space available for static Thread Local Storage", 4014 obj->path); 4015 result = -1; 4016 } 4017 if (result != -1) 4018 result = load_needed_objects(obj, 4019 lo_flags & (RTLD_LO_DLOPEN | RTLD_LO_EARLY | 4020 RTLD_LO_IGNSTLS | RTLD_LO_TRACE)); 4021 init_dag(obj); 4022 ref_dag(obj); 4023 if (result != -1) 4024 result = rtld_verify_versions(&obj->dagmembers); 4025 if (result != -1 && ld_tracing) 4026 goto trace; 4027 if (result == -1 || relocate_object_dag(obj, 4028 (mode & RTLD_MODEMASK) == RTLD_NOW, &obj_rtld, 4029 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 4030 lockstate) == -1) { 4031 dlopen_cleanup(obj, lockstate); 4032 obj = NULL; 4033 } else if ((lo_flags & RTLD_LO_EARLY) != 0) { 4034 /* 4035 * Do not call the init functions for early 4036 * loaded filtees. The image is still not 4037 * initialized enough for them to work. 4038 * 4039 * Our object is found by the global object list 4040 * and will be ordered among all init calls done 4041 * right before transferring control to main. 4042 */ 4043 } else { 4044 /* Make list of init functions to call. */ 4045 initlist_for_loaded_obj(obj, obj, &initlist); 4046 } 4047 /* 4048 * Process all no_delete or global objects here, given 4049 * them own DAGs to prevent their dependencies from 4050 * being unloaded. This has to be done after we have 4051 * loaded all of the dependencies, so that we do not 4052 * miss any. 4053 */ 4054 if (obj != NULL) 4055 process_z(obj); 4056 } else { 4057 /* 4058 * Bump the reference counts for objects on this DAG. If 4059 * this is the first dlopen() call for the object that 4060 * was already loaded as a dependency, initialize the 4061 * dag starting at it. 4062 */ 4063 init_dag(obj); 4064 ref_dag(obj); 4065 4066 if ((lo_flags & RTLD_LO_TRACE) != 0) 4067 goto trace; 4068 } 4069 if (obj != NULL && 4070 ((lo_flags & RTLD_LO_NODELETE) != 0 || obj->z_nodelete) && 4071 !obj->ref_nodel) { 4072 dbg("obj %s nodelete", obj->path); 4073 ref_dag(obj); 4074 obj->z_nodelete = obj->ref_nodel = true; 4075 } 4076 } 4077 4078 LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0, 4079 name); 4080 GDB_STATE(RT_CONSISTENT, obj ? &obj->linkmap : NULL); 4081 4082 if ((lo_flags & RTLD_LO_EARLY) == 0) { 4083 map_stacks_exec(lockstate); 4084 if (obj != NULL) 4085 distribute_static_tls(&initlist); 4086 } 4087 4088 if (initlist_objects_ifunc(&initlist, (mode & RTLD_MODEMASK) == 4089 RTLD_NOW, (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 4090 lockstate) == -1) { 4091 objlist_clear(&initlist); 4092 dlopen_cleanup(obj, lockstate); 4093 if (lockstate == &mlockstate) 4094 lock_release(rtld_bind_lock, lockstate); 4095 return (NULL); 4096 } 4097 4098 if ((lo_flags & RTLD_LO_EARLY) == 0) { 4099 /* Call the init functions. */ 4100 objlist_call_init(&initlist, lockstate); 4101 } 4102 objlist_clear(&initlist); 4103 if (lockstate == &mlockstate) 4104 lock_release(rtld_bind_lock, lockstate); 4105 return (obj); 4106 trace: 4107 trace_loaded_objects(obj, false); 4108 if (lockstate == &mlockstate) 4109 lock_release(rtld_bind_lock, lockstate); 4110 exit(0); 4111 } 4112 4113 static void * 4114 do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve, 4115 int flags) 4116 { 4117 DoneList donelist; 4118 const Obj_Entry *obj, *defobj; 4119 const Elf_Sym *def; 4120 SymLook req; 4121 RtldLockState lockstate; 4122 tls_index ti; 4123 void *sym; 4124 int res; 4125 4126 def = NULL; 4127 defobj = NULL; 4128 symlook_init(&req, name); 4129 req.ventry = ve; 4130 req.flags = flags | SYMLOOK_IN_PLT; 4131 req.lockstate = &lockstate; 4132 4133 LD_UTRACE(UTRACE_DLSYM_START, handle, NULL, 0, 0, name); 4134 rlock_acquire(rtld_bind_lock, &lockstate); 4135 if (sigsetjmp(lockstate.env, 0) != 0) { 4136 lock_upgrade(rtld_bind_lock, &lockstate); 4137 free(req.donelist_mem); 4138 req.donelist_mem = NULL; 4139 } 4140 if (handle == NULL || handle == RTLD_NEXT || handle == RTLD_DEFAULT || 4141 handle == RTLD_SELF) { 4142 if ((obj = obj_from_addr(retaddr)) == NULL) { 4143 _rtld_error("Cannot determine caller's shared object"); 4144 lock_release(rtld_bind_lock, &lockstate); 4145 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 4146 return (NULL); 4147 } 4148 if (handle == NULL) { /* Just the caller's shared object. */ 4149 res = symlook_obj(&req, obj); 4150 if (res == 0) { 4151 def = req.sym_out; 4152 defobj = req.defobj_out; 4153 } 4154 } else if (handle == RTLD_NEXT || /* Objects after caller's */ 4155 handle == RTLD_SELF) { /* ... caller included */ 4156 if (handle == RTLD_NEXT) 4157 obj = globallist_next(obj); 4158 for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 4159 if (obj->marker) 4160 continue; 4161 res = symlook_obj(&req, obj); 4162 if (res == 0) { 4163 if (def == NULL || 4164 (ld_dynamic_weak && 4165 ELF_ST_BIND( 4166 req.sym_out->st_info) != 4167 STB_WEAK)) { 4168 def = req.sym_out; 4169 defobj = req.defobj_out; 4170 if (!ld_dynamic_weak || 4171 ELF_ST_BIND(def->st_info) != 4172 STB_WEAK) 4173 break; 4174 } 4175 } 4176 } 4177 /* 4178 * Search the dynamic linker itself, and possibly 4179 * resolve the symbol from there. This is how the 4180 * application links to dynamic linker services such as 4181 * dlopen. Note that we ignore ld_dynamic_weak == false 4182 * case, always overriding weak symbols by rtld 4183 * definitions. 4184 */ 4185 if (def == NULL || 4186 ELF_ST_BIND(def->st_info) == STB_WEAK) { 4187 res = symlook_obj(&req, &obj_rtld); 4188 if (res == 0) { 4189 def = req.sym_out; 4190 defobj = req.defobj_out; 4191 } 4192 } 4193 } else { 4194 assert(handle == RTLD_DEFAULT); 4195 res = symlook_default(&req, obj); 4196 if (res == 0) { 4197 defobj = req.defobj_out; 4198 def = req.sym_out; 4199 } 4200 } 4201 } else { 4202 if ((obj = dlcheck(handle)) == NULL) { 4203 lock_release(rtld_bind_lock, &lockstate); 4204 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 4205 return (NULL); 4206 } 4207 4208 donelist_init(&donelist, &req); 4209 if (obj->mainprog) { 4210 /* Handle obtained by dlopen(NULL, ...) implies global 4211 * scope. */ 4212 res = symlook_global(&req, &donelist); 4213 if (res == 0) { 4214 def = req.sym_out; 4215 defobj = req.defobj_out; 4216 } 4217 /* 4218 * Search the dynamic linker itself, and possibly 4219 * resolve the symbol from there. This is how the 4220 * application links to dynamic linker services such as 4221 * dlopen. 4222 */ 4223 if (def == NULL || 4224 ELF_ST_BIND(def->st_info) == STB_WEAK) { 4225 res = symlook_obj(&req, &obj_rtld); 4226 if (res == 0) { 4227 def = req.sym_out; 4228 defobj = req.defobj_out; 4229 } 4230 } 4231 } else { 4232 /* Search the whole DAG rooted at the given object. */ 4233 res = symlook_list(&req, &obj->dagmembers, &donelist); 4234 if (res == 0) { 4235 def = req.sym_out; 4236 defobj = req.defobj_out; 4237 } 4238 } 4239 donelist_free(&donelist); 4240 } 4241 4242 if (def != NULL) { 4243 lock_release(rtld_bind_lock, &lockstate); 4244 4245 /* 4246 * The value required by the caller is derived from the value 4247 * of the symbol. this is simply the relocated value of the 4248 * symbol. 4249 */ 4250 if (ELF_ST_TYPE(def->st_info) == STT_FUNC) 4251 sym = make_function_pointer(def, defobj); 4252 else if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 4253 sym = rtld_resolve_ifunc(defobj, def); 4254 else if (ELF_ST_TYPE(def->st_info) == STT_TLS) { 4255 ti.ti_module = defobj->tlsindex; 4256 ti.ti_offset = def->st_value - TLS_DTV_OFFSET; 4257 sym = __tls_get_addr(&ti); 4258 } else 4259 sym = defobj->relocbase + def->st_value; 4260 LD_UTRACE(UTRACE_DLSYM_STOP, handle, sym, 0, 0, name); 4261 return (sym); 4262 } 4263 4264 _rtld_error("Undefined symbol \"%s%s%s\"", name, ve != NULL ? "@" : "", 4265 ve != NULL ? ve->name : ""); 4266 lock_release(rtld_bind_lock, &lockstate); 4267 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 4268 return (NULL); 4269 } 4270 4271 void * 4272 dlsym(void *handle, const char *name) 4273 { 4274 return (do_dlsym(handle, name, __builtin_return_address(0), NULL, 4275 SYMLOOK_DLSYM)); 4276 } 4277 4278 dlfunc_t 4279 dlfunc(void *handle, const char *name) 4280 { 4281 union { 4282 void *d; 4283 dlfunc_t f; 4284 } rv; 4285 4286 rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL, 4287 SYMLOOK_DLSYM); 4288 return (rv.f); 4289 } 4290 4291 void * 4292 dlvsym(void *handle, const char *name, const char *version) 4293 { 4294 Ver_Entry ventry; 4295 4296 ventry.name = version; 4297 ventry.file = NULL; 4298 ventry.hash = elf_hash(version); 4299 ventry.flags = 0; 4300 return (do_dlsym(handle, name, __builtin_return_address(0), &ventry, 4301 SYMLOOK_DLSYM)); 4302 } 4303 4304 int 4305 _rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info) 4306 { 4307 const Obj_Entry *obj; 4308 RtldLockState lockstate; 4309 4310 rlock_acquire(rtld_bind_lock, &lockstate); 4311 obj = obj_from_addr(addr); 4312 if (obj == NULL) { 4313 _rtld_error("No shared object contains address"); 4314 lock_release(rtld_bind_lock, &lockstate); 4315 return (0); 4316 } 4317 rtld_fill_dl_phdr_info(obj, phdr_info); 4318 lock_release(rtld_bind_lock, &lockstate); 4319 return (1); 4320 } 4321 4322 int 4323 dladdr(const void *addr, Dl_info *info) 4324 { 4325 const Obj_Entry *obj; 4326 const Elf_Sym *def; 4327 void *symbol_addr; 4328 unsigned long symoffset; 4329 RtldLockState lockstate; 4330 4331 rlock_acquire(rtld_bind_lock, &lockstate); 4332 obj = obj_from_addr(addr); 4333 if (obj == NULL) { 4334 _rtld_error("No shared object contains address"); 4335 lock_release(rtld_bind_lock, &lockstate); 4336 return (0); 4337 } 4338 info->dli_fname = obj->path; 4339 info->dli_fbase = obj->mapbase; 4340 info->dli_saddr = (void *)0; 4341 info->dli_sname = NULL; 4342 4343 /* 4344 * Walk the symbol list looking for the symbol whose address is 4345 * closest to the address sent in. 4346 */ 4347 for (symoffset = 0; symoffset < obj->dynsymcount; symoffset++) { 4348 def = obj->symtab + symoffset; 4349 4350 /* 4351 * For skip the symbol if st_shndx is either SHN_UNDEF or 4352 * SHN_COMMON. 4353 */ 4354 if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON) 4355 continue; 4356 4357 /* 4358 * If the symbol is greater than the specified address, or if it 4359 * is further away from addr than the current nearest symbol, 4360 * then reject it. 4361 */ 4362 symbol_addr = obj->relocbase + def->st_value; 4363 if (symbol_addr > addr || symbol_addr < info->dli_saddr) 4364 continue; 4365 4366 /* Update our idea of the nearest symbol. */ 4367 info->dli_sname = obj->strtab + def->st_name; 4368 info->dli_saddr = symbol_addr; 4369 4370 /* Exact match? */ 4371 if (info->dli_saddr == addr) 4372 break; 4373 } 4374 lock_release(rtld_bind_lock, &lockstate); 4375 return (1); 4376 } 4377 4378 int 4379 dlinfo(void *handle, int request, void *p) 4380 { 4381 const Obj_Entry *obj; 4382 RtldLockState lockstate; 4383 int error; 4384 4385 rlock_acquire(rtld_bind_lock, &lockstate); 4386 4387 if (handle == NULL || handle == RTLD_SELF) { 4388 void *retaddr; 4389 4390 retaddr = __builtin_return_address(0); /* __GNUC__ only */ 4391 if ((obj = obj_from_addr(retaddr)) == NULL) 4392 _rtld_error("Cannot determine caller's shared object"); 4393 } else 4394 obj = dlcheck(handle); 4395 4396 if (obj == NULL) { 4397 lock_release(rtld_bind_lock, &lockstate); 4398 return (-1); 4399 } 4400 4401 error = 0; 4402 switch (request) { 4403 case RTLD_DI_LINKMAP: 4404 *((struct link_map const **)p) = &obj->linkmap; 4405 break; 4406 case RTLD_DI_ORIGIN: 4407 error = rtld_dirname(obj->path, p); 4408 break; 4409 4410 case RTLD_DI_SERINFOSIZE: 4411 case RTLD_DI_SERINFO: 4412 error = do_search_info(obj, request, (struct dl_serinfo *)p); 4413 break; 4414 4415 default: 4416 _rtld_error("Invalid request %d passed to dlinfo()", request); 4417 error = -1; 4418 } 4419 4420 lock_release(rtld_bind_lock, &lockstate); 4421 4422 return (error); 4423 } 4424 4425 static void 4426 rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info) 4427 { 4428 phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase; 4429 phdr_info->dlpi_name = obj->path; 4430 phdr_info->dlpi_phdr = obj->phdr; 4431 phdr_info->dlpi_phnum = obj->phnum; 4432 phdr_info->dlpi_tls_modid = obj->tlsindex; 4433 phdr_info->dlpi_tls_data = (char *)tls_get_addr_slow(_tcb_get(), 4434 obj->tlsindex, 0, true); 4435 phdr_info->dlpi_adds = obj_loads; 4436 phdr_info->dlpi_subs = obj_loads - obj_count; 4437 } 4438 4439 /* 4440 * It's completely UB to actually use this, so extreme caution is advised. It's 4441 * probably not what you want. 4442 */ 4443 int 4444 _dl_iterate_phdr_locked(__dl_iterate_hdr_callback callback, void *param) 4445 { 4446 struct dl_phdr_info phdr_info; 4447 Obj_Entry *obj; 4448 int error; 4449 4450 for (obj = globallist_curr(TAILQ_FIRST(&obj_list)); obj != NULL; 4451 obj = globallist_next(obj)) { 4452 rtld_fill_dl_phdr_info(obj, &phdr_info); 4453 error = callback(&phdr_info, sizeof(phdr_info), param); 4454 if (error != 0) 4455 return (error); 4456 } 4457 4458 rtld_fill_dl_phdr_info(&obj_rtld, &phdr_info); 4459 return (callback(&phdr_info, sizeof(phdr_info), param)); 4460 } 4461 4462 int 4463 dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param) 4464 { 4465 struct dl_phdr_info phdr_info; 4466 Obj_Entry *obj, marker; 4467 RtldLockState bind_lockstate, phdr_lockstate; 4468 int error; 4469 4470 init_marker(&marker); 4471 error = 0; 4472 4473 wlock_acquire(rtld_phdr_lock, &phdr_lockstate); 4474 wlock_acquire(rtld_bind_lock, &bind_lockstate); 4475 for (obj = globallist_curr(TAILQ_FIRST(&obj_list)); obj != NULL;) { 4476 TAILQ_INSERT_AFTER(&obj_list, obj, &marker, next); 4477 rtld_fill_dl_phdr_info(obj, &phdr_info); 4478 hold_object(obj); 4479 lock_release(rtld_bind_lock, &bind_lockstate); 4480 4481 error = callback(&phdr_info, sizeof phdr_info, param); 4482 4483 wlock_acquire(rtld_bind_lock, &bind_lockstate); 4484 unhold_object(obj); 4485 obj = globallist_next(&marker); 4486 TAILQ_REMOVE(&obj_list, &marker, next); 4487 if (error != 0) { 4488 lock_release(rtld_bind_lock, &bind_lockstate); 4489 lock_release(rtld_phdr_lock, &phdr_lockstate); 4490 return (error); 4491 } 4492 } 4493 4494 if (error == 0) { 4495 rtld_fill_dl_phdr_info(&obj_rtld, &phdr_info); 4496 lock_release(rtld_bind_lock, &bind_lockstate); 4497 error = callback(&phdr_info, sizeof(phdr_info), param); 4498 } 4499 lock_release(rtld_phdr_lock, &phdr_lockstate); 4500 return (error); 4501 } 4502 4503 static void * 4504 fill_search_info(const char *dir, size_t dirlen, void *param) 4505 { 4506 struct fill_search_info_args *arg; 4507 4508 arg = param; 4509 4510 if (arg->request == RTLD_DI_SERINFOSIZE) { 4511 arg->serinfo->dls_cnt++; 4512 arg->serinfo->dls_size += sizeof(struct dl_serpath) + dirlen + 4513 1; 4514 } else { 4515 struct dl_serpath *s_entry; 4516 4517 s_entry = arg->serpath; 4518 s_entry->dls_name = arg->strspace; 4519 s_entry->dls_flags = arg->flags; 4520 4521 strncpy(arg->strspace, dir, dirlen); 4522 arg->strspace[dirlen] = '\0'; 4523 4524 arg->strspace += dirlen + 1; 4525 arg->serpath++; 4526 } 4527 4528 return (NULL); 4529 } 4530 4531 static int 4532 do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info) 4533 { 4534 struct dl_serinfo _info; 4535 struct fill_search_info_args args; 4536 4537 args.request = RTLD_DI_SERINFOSIZE; 4538 args.serinfo = &_info; 4539 4540 _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 4541 _info.dls_cnt = 0; 4542 4543 path_enumerate(obj->rpath, fill_search_info, NULL, &args); 4544 path_enumerate(ld_library_path, fill_search_info, NULL, &args); 4545 path_enumerate(obj->runpath, fill_search_info, NULL, &args); 4546 path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, 4547 &args); 4548 if (!obj->z_nodeflib) 4549 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 4550 &args); 4551 4552 if (request == RTLD_DI_SERINFOSIZE) { 4553 info->dls_size = _info.dls_size; 4554 info->dls_cnt = _info.dls_cnt; 4555 return (0); 4556 } 4557 4558 if (info->dls_cnt != _info.dls_cnt || 4559 info->dls_size != _info.dls_size) { 4560 _rtld_error( 4561 "Uninitialized Dl_serinfo struct passed to dlinfo()"); 4562 return (-1); 4563 } 4564 4565 args.request = RTLD_DI_SERINFO; 4566 args.serinfo = info; 4567 args.serpath = &info->dls_serpath[0]; 4568 args.strspace = (char *)&info->dls_serpath[_info.dls_cnt]; 4569 4570 args.flags = LA_SER_RUNPATH; 4571 if (path_enumerate(obj->rpath, fill_search_info, NULL, &args) != NULL) 4572 return (-1); 4573 4574 args.flags = LA_SER_LIBPATH; 4575 if (path_enumerate(ld_library_path, fill_search_info, NULL, &args) != 4576 NULL) 4577 return (-1); 4578 4579 args.flags = LA_SER_RUNPATH; 4580 if (path_enumerate(obj->runpath, fill_search_info, NULL, &args) != NULL) 4581 return (-1); 4582 4583 args.flags = LA_SER_CONFIG; 4584 if (path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, 4585 &args) != NULL) 4586 return (-1); 4587 4588 args.flags = LA_SER_DEFAULT; 4589 if (!obj->z_nodeflib && 4590 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 4591 &args) != NULL) 4592 return (-1); 4593 return (0); 4594 } 4595 4596 static int 4597 rtld_dirname(const char *path, char *bname) 4598 { 4599 const char *endp; 4600 4601 /* Empty or NULL string gets treated as "." */ 4602 if (path == NULL || *path == '\0') { 4603 bname[0] = '.'; 4604 bname[1] = '\0'; 4605 return (0); 4606 } 4607 4608 /* Strip trailing slashes */ 4609 endp = path + strlen(path) - 1; 4610 while (endp > path && *endp == '/') 4611 endp--; 4612 4613 /* Find the start of the dir */ 4614 while (endp > path && *endp != '/') 4615 endp--; 4616 4617 /* Either the dir is "/" or there are no slashes */ 4618 if (endp == path) { 4619 bname[0] = *endp == '/' ? '/' : '.'; 4620 bname[1] = '\0'; 4621 return (0); 4622 } else { 4623 do { 4624 endp--; 4625 } while (endp > path && *endp == '/'); 4626 } 4627 4628 if (endp - path + 2 > PATH_MAX) { 4629 _rtld_error("Filename is too long: %s", path); 4630 return (-1); 4631 } 4632 4633 strncpy(bname, path, endp - path + 1); 4634 bname[endp - path + 1] = '\0'; 4635 return (0); 4636 } 4637 4638 static int 4639 rtld_dirname_abs(const char *path, char *base) 4640 { 4641 char *last; 4642 4643 if (realpath(path, base) == NULL) { 4644 _rtld_error("realpath \"%s\" failed (%s)", path, 4645 rtld_strerror(errno)); 4646 return (-1); 4647 } 4648 dbg("%s -> %s", path, base); 4649 last = strrchr(base, '/'); 4650 if (last == NULL) { 4651 _rtld_error("non-abs result from realpath \"%s\"", path); 4652 return (-1); 4653 } 4654 if (last != base) 4655 *last = '\0'; 4656 return (0); 4657 } 4658 4659 static void 4660 linkmap_add(Obj_Entry *obj) 4661 { 4662 struct link_map *l, *prev; 4663 4664 l = &obj->linkmap; 4665 l->l_name = obj->path; 4666 l->l_base = obj->mapbase; 4667 l->l_ld = obj->dynamic; 4668 l->l_addr = obj->relocbase; 4669 4670 if (r_debug.r_map == NULL) { 4671 r_debug.r_map = l; 4672 return; 4673 } 4674 4675 /* 4676 * Scan to the end of the list, but not past the entry for the 4677 * dynamic linker, which we want to keep at the very end. 4678 */ 4679 for (prev = r_debug.r_map; 4680 prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap; 4681 prev = prev->l_next) 4682 ; 4683 4684 /* Link in the new entry. */ 4685 l->l_prev = prev; 4686 l->l_next = prev->l_next; 4687 if (l->l_next != NULL) 4688 l->l_next->l_prev = l; 4689 prev->l_next = l; 4690 } 4691 4692 static void 4693 linkmap_delete(Obj_Entry *obj) 4694 { 4695 struct link_map *l; 4696 4697 l = &obj->linkmap; 4698 if (l->l_prev == NULL) { 4699 if ((r_debug.r_map = l->l_next) != NULL) 4700 l->l_next->l_prev = NULL; 4701 return; 4702 } 4703 4704 if ((l->l_prev->l_next = l->l_next) != NULL) 4705 l->l_next->l_prev = l->l_prev; 4706 } 4707 4708 /* 4709 * Function for the debugger to set a breakpoint on to gain control. 4710 * 4711 * The two parameters allow the debugger to easily find and determine 4712 * what the runtime loader is doing and to whom it is doing it. 4713 * 4714 * When the loadhook trap is hit (r_debug_state, set at program 4715 * initialization), the arguments can be found on the stack: 4716 * 4717 * +8 struct link_map *m 4718 * +4 struct r_debug *rd 4719 * +0 RetAddr 4720 */ 4721 void 4722 r_debug_state(struct r_debug *rd __unused, struct link_map *m __unused) 4723 { 4724 /* 4725 * The following is a hack to force the compiler to emit calls to 4726 * this function, even when optimizing. If the function is empty, 4727 * the compiler is not obliged to emit any code for calls to it, 4728 * even when marked __noinline. However, gdb depends on those 4729 * calls being made. 4730 */ 4731 __compiler_membar(); 4732 } 4733 4734 /* 4735 * A function called after init routines have completed. This can be used to 4736 * break before a program's entry routine is called, and can be used when 4737 * main is not available in the symbol table. 4738 */ 4739 void 4740 _r_debug_postinit(struct link_map *m __unused) 4741 { 4742 /* See r_debug_state(). */ 4743 __compiler_membar(); 4744 } 4745 4746 static void 4747 release_object(Obj_Entry *obj) 4748 { 4749 if (obj->holdcount > 0) { 4750 obj->unholdfree = true; 4751 return; 4752 } 4753 munmap(obj->mapbase, obj->mapsize); 4754 linkmap_delete(obj); 4755 obj_free(obj); 4756 } 4757 4758 /* 4759 * Get address of the pointer variable in the main program. 4760 * Prefer non-weak symbol over the weak one. 4761 */ 4762 static const void ** 4763 get_program_var_addr(const char *name, RtldLockState *lockstate) 4764 { 4765 SymLook req; 4766 DoneList donelist; 4767 const void **res; 4768 4769 symlook_init(&req, name); 4770 req.lockstate = lockstate; 4771 donelist_init(&donelist, NULL); 4772 if (symlook_global(&req, &donelist) != 0) 4773 return (NULL); 4774 if (ELF_ST_TYPE(req.sym_out->st_info) == STT_FUNC) 4775 res = (const void **)make_function_pointer(req.sym_out, 4776 req.defobj_out); 4777 else if (ELF_ST_TYPE(req.sym_out->st_info) == STT_GNU_IFUNC) 4778 res = (const void **)rtld_resolve_ifunc(req.defobj_out, 4779 req.sym_out); 4780 else 4781 res = (const void **)(req.defobj_out->relocbase + 4782 req.sym_out->st_value); 4783 donelist_free(&donelist); 4784 return (res); 4785 } 4786 4787 /* 4788 * Set a pointer variable in the main program to the given value. This 4789 * is used to set key variables such as "environ" before any of the 4790 * init functions are called. 4791 */ 4792 static void 4793 set_program_var(const char *name, const void *value) 4794 { 4795 const void **addr; 4796 4797 if ((addr = get_program_var_addr(name, NULL)) != NULL) { 4798 dbg("\"%s\": *%p <-- %p", name, addr, value); 4799 *addr = value; 4800 } 4801 } 4802 4803 /* 4804 * Search the global objects, including dependencies and main object, 4805 * for the given symbol. 4806 */ 4807 static int 4808 symlook_global(SymLook *req, DoneList *donelist) 4809 { 4810 SymLook req1; 4811 const Objlist_Entry *elm; 4812 int res; 4813 4814 symlook_init_from_req(&req1, req); 4815 4816 /* Search all objects loaded at program start up. */ 4817 if (req->defobj_out == NULL || (ld_dynamic_weak && 4818 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK)) { 4819 res = symlook_list(&req1, &list_main, donelist); 4820 if (res == 0 && (!ld_dynamic_weak || req->defobj_out == NULL || 4821 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4822 req->sym_out = req1.sym_out; 4823 req->defobj_out = req1.defobj_out; 4824 assert(req->defobj_out != NULL); 4825 } 4826 } 4827 4828 /* Search all DAGs whose roots are RTLD_GLOBAL objects. */ 4829 STAILQ_FOREACH(elm, &list_global, link) { 4830 if (req->defobj_out != NULL && (!ld_dynamic_weak || 4831 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK)) 4832 break; 4833 res = symlook_list(&req1, &elm->obj->dagmembers, donelist); 4834 if (res == 0 && (req->defobj_out == NULL || 4835 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4836 req->sym_out = req1.sym_out; 4837 req->defobj_out = req1.defobj_out; 4838 assert(req->defobj_out != NULL); 4839 } 4840 } 4841 4842 return (req->sym_out != NULL ? 0 : ESRCH); 4843 } 4844 4845 /* 4846 * Given a symbol name in a referencing object, find the corresponding 4847 * definition of the symbol. Returns a pointer to the symbol, or NULL if 4848 * no definition was found. Returns a pointer to the Obj_Entry of the 4849 * defining object via the reference parameter DEFOBJ_OUT. 4850 */ 4851 static int 4852 symlook_default(SymLook *req, const Obj_Entry *refobj) 4853 { 4854 DoneList donelist; 4855 const Objlist_Entry *elm; 4856 SymLook req1; 4857 int res; 4858 4859 donelist_init(&donelist, req); 4860 symlook_init_from_req(&req1, req); 4861 4862 /* 4863 * Look first in the referencing object if linked symbolically, 4864 * and similarly handle protected symbols. 4865 */ 4866 res = symlook_obj(&req1, refobj); 4867 if (res == 0 && (refobj->symbolic || 4868 ELF_ST_VISIBILITY(req1.sym_out->st_other) == STV_PROTECTED || 4869 refobj->deepbind)) { 4870 req->sym_out = req1.sym_out; 4871 req->defobj_out = req1.defobj_out; 4872 assert(req->defobj_out != NULL); 4873 } 4874 if (refobj->symbolic || req->defobj_out != NULL || refobj->deepbind) 4875 donelist_check(&donelist, refobj); 4876 4877 if (!refobj->deepbind) 4878 symlook_global(req, &donelist); 4879 4880 /* Search all dlopened DAGs containing the referencing object. */ 4881 STAILQ_FOREACH(elm, &refobj->dldags, link) { 4882 if (req->sym_out != NULL && (!ld_dynamic_weak || 4883 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK)) 4884 break; 4885 res = symlook_list(&req1, &elm->obj->dagmembers, &donelist); 4886 if (res == 0 && (req->sym_out == NULL || 4887 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4888 req->sym_out = req1.sym_out; 4889 req->defobj_out = req1.defobj_out; 4890 assert(req->defobj_out != NULL); 4891 } 4892 } 4893 4894 if (refobj->deepbind) 4895 symlook_global(req, &donelist); 4896 4897 /* 4898 * Search the dynamic linker itself, and possibly resolve the 4899 * symbol from there. This is how the application links to 4900 * dynamic linker services such as dlopen. 4901 */ 4902 if (req->sym_out == NULL || 4903 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 4904 res = symlook_obj(&req1, &obj_rtld); 4905 if (res == 0) { 4906 req->sym_out = req1.sym_out; 4907 req->defobj_out = req1.defobj_out; 4908 assert(req->defobj_out != NULL); 4909 } 4910 } 4911 4912 donelist_free(&donelist); 4913 return (req->sym_out != NULL ? 0 : ESRCH); 4914 } 4915 4916 static int 4917 symlook_list(SymLook *req, const Objlist *objlist, DoneList *dlp) 4918 { 4919 const Elf_Sym *def; 4920 const Obj_Entry *defobj; 4921 const Objlist_Entry *elm; 4922 SymLook req1; 4923 int res; 4924 4925 def = NULL; 4926 defobj = NULL; 4927 STAILQ_FOREACH(elm, objlist, link) { 4928 if (donelist_check(dlp, elm->obj)) 4929 continue; 4930 symlook_init_from_req(&req1, req); 4931 if ((res = symlook_obj(&req1, elm->obj)) == 0) { 4932 if (def == NULL || (ld_dynamic_weak && 4933 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4934 def = req1.sym_out; 4935 defobj = req1.defobj_out; 4936 if (!ld_dynamic_weak || 4937 ELF_ST_BIND(def->st_info) != STB_WEAK) 4938 break; 4939 } 4940 } 4941 } 4942 if (def != NULL) { 4943 req->sym_out = def; 4944 req->defobj_out = defobj; 4945 return (0); 4946 } 4947 return (ESRCH); 4948 } 4949 4950 /* 4951 * Search the chain of DAGS cointed to by the given Needed_Entry 4952 * for a symbol of the given name. Each DAG is scanned completely 4953 * before advancing to the next one. Returns a pointer to the symbol, 4954 * or NULL if no definition was found. 4955 */ 4956 static int 4957 symlook_needed(SymLook *req, const Needed_Entry *needed, DoneList *dlp) 4958 { 4959 const Elf_Sym *def; 4960 const Needed_Entry *n; 4961 const Obj_Entry *defobj; 4962 SymLook req1; 4963 int res; 4964 4965 def = NULL; 4966 defobj = NULL; 4967 symlook_init_from_req(&req1, req); 4968 for (n = needed; n != NULL; n = n->next) { 4969 if (n->obj == NULL || (res = symlook_list(&req1, 4970 &n->obj->dagmembers, dlp)) != 0) 4971 continue; 4972 if (def == NULL || (ld_dynamic_weak && 4973 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4974 def = req1.sym_out; 4975 defobj = req1.defobj_out; 4976 if (!ld_dynamic_weak || 4977 ELF_ST_BIND(def->st_info) != STB_WEAK) 4978 break; 4979 } 4980 } 4981 if (def != NULL) { 4982 req->sym_out = def; 4983 req->defobj_out = defobj; 4984 return (0); 4985 } 4986 return (ESRCH); 4987 } 4988 4989 static int 4990 symlook_obj_load_filtees(SymLook *req, SymLook *req1, const Obj_Entry *obj, 4991 Needed_Entry *needed) 4992 { 4993 DoneList donelist; 4994 int flags, res; 4995 4996 flags = (req->flags & SYMLOOK_EARLY) != 0 ? RTLD_LO_EARLY : 0; 4997 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 4998 donelist_init(&donelist, NULL); 4999 symlook_init_from_req(req1, req); 5000 res = symlook_needed(req1, needed, &donelist); 5001 donelist_free(&donelist); 5002 return (res); 5003 } 5004 5005 /* 5006 * Search the symbol table of a single shared object for a symbol of 5007 * the given name and version, if requested. Returns a pointer to the 5008 * symbol, or NULL if no definition was found. If the object is 5009 * filter, return filtered symbol from filtee. 5010 * 5011 * The symbol's hash value is passed in for efficiency reasons; that 5012 * eliminates many recomputations of the hash value. 5013 */ 5014 int 5015 symlook_obj(SymLook *req, const Obj_Entry *obj) 5016 { 5017 SymLook req1; 5018 int res, mres; 5019 5020 /* 5021 * If there is at least one valid hash at this point, we prefer to 5022 * use the faster GNU version if available. 5023 */ 5024 if (obj->valid_hash_gnu) 5025 mres = symlook_obj1_gnu(req, obj); 5026 else if (obj->valid_hash_sysv) 5027 mres = symlook_obj1_sysv(req, obj); 5028 else 5029 return (EINVAL); 5030 5031 if (mres == 0) { 5032 if (obj->needed_filtees != NULL) { 5033 res = symlook_obj_load_filtees(req, &req1, obj, 5034 obj->needed_filtees); 5035 if (res == 0) { 5036 req->sym_out = req1.sym_out; 5037 req->defobj_out = req1.defobj_out; 5038 } 5039 return (res); 5040 } 5041 if (obj->needed_aux_filtees != NULL) { 5042 res = symlook_obj_load_filtees(req, &req1, obj, 5043 obj->needed_aux_filtees); 5044 if (res == 0) { 5045 req->sym_out = req1.sym_out; 5046 req->defobj_out = req1.defobj_out; 5047 return (res); 5048 } 5049 } 5050 } 5051 return (mres); 5052 } 5053 5054 /* Symbol match routine common to both hash functions */ 5055 static bool 5056 matched_symbol(SymLook *req, const Obj_Entry *obj, Sym_Match_Result *result, 5057 const unsigned long symnum) 5058 { 5059 Elf_Versym verndx; 5060 const Elf_Sym *symp; 5061 const char *strp; 5062 5063 symp = obj->symtab + symnum; 5064 strp = obj->strtab + symp->st_name; 5065 5066 switch (ELF_ST_TYPE(symp->st_info)) { 5067 case STT_FUNC: 5068 case STT_NOTYPE: 5069 case STT_OBJECT: 5070 case STT_COMMON: 5071 case STT_GNU_IFUNC: 5072 if (symp->st_value == 0) 5073 return (false); 5074 /* fallthrough */ 5075 case STT_TLS: 5076 if (symp->st_shndx != SHN_UNDEF) 5077 break; 5078 else if (((req->flags & SYMLOOK_IN_PLT) == 0) && 5079 (ELF_ST_TYPE(symp->st_info) == STT_FUNC)) 5080 break; 5081 /* fallthrough */ 5082 default: 5083 return (false); 5084 } 5085 if (req->name[0] != strp[0] || strcmp(req->name, strp) != 0) 5086 return (false); 5087 5088 if (req->ventry == NULL) { 5089 if (obj->versyms != NULL) { 5090 verndx = VER_NDX(obj->versyms[symnum]); 5091 if (verndx > obj->vernum) { 5092 _rtld_error( 5093 "%s: symbol %s references wrong version %d", 5094 obj->path, obj->strtab + symnum, verndx); 5095 return (false); 5096 } 5097 /* 5098 * If we are not called from dlsym (i.e. this 5099 * is a normal relocation from unversioned 5100 * binary), accept the symbol immediately if 5101 * it happens to have first version after this 5102 * shared object became versioned. Otherwise, 5103 * if symbol is versioned and not hidden, 5104 * remember it. If it is the only symbol with 5105 * this name exported by the shared object, it 5106 * will be returned as a match by the calling 5107 * function. If symbol is global (verndx < 2) 5108 * accept it unconditionally. 5109 */ 5110 if ((req->flags & SYMLOOK_DLSYM) == 0 && 5111 verndx == VER_NDX_GIVEN) { 5112 result->sym_out = symp; 5113 return (true); 5114 } else if (verndx >= VER_NDX_GIVEN) { 5115 if ((obj->versyms[symnum] & VER_NDX_HIDDEN) == 5116 0) { 5117 if (result->vsymp == NULL) 5118 result->vsymp = symp; 5119 result->vcount++; 5120 } 5121 return (false); 5122 } 5123 } 5124 result->sym_out = symp; 5125 return (true); 5126 } 5127 if (obj->versyms == NULL) { 5128 if (object_match_name(obj, req->ventry->name)) { 5129 _rtld_error( 5130 "%s: object %s should provide version %s for symbol %s", 5131 obj_rtld.path, obj->path, req->ventry->name, 5132 obj->strtab + symnum); 5133 return (false); 5134 } 5135 } else { 5136 verndx = VER_NDX(obj->versyms[symnum]); 5137 if (verndx > obj->vernum) { 5138 _rtld_error("%s: symbol %s references wrong version %d", 5139 obj->path, obj->strtab + symnum, verndx); 5140 return (false); 5141 } 5142 if (obj->vertab[verndx].hash != req->ventry->hash || 5143 strcmp(obj->vertab[verndx].name, req->ventry->name)) { 5144 /* 5145 * Version does not match. Look if this is a 5146 * global symbol and if it is not hidden. If 5147 * global symbol (verndx < 2) is available, 5148 * use it. Do not return symbol if we are 5149 * called by dlvsym, because dlvsym looks for 5150 * a specific version and default one is not 5151 * what dlvsym wants. 5152 */ 5153 if ((req->flags & SYMLOOK_DLSYM) || 5154 (verndx >= VER_NDX_GIVEN) || 5155 (obj->versyms[symnum] & VER_NDX_HIDDEN)) 5156 return (false); 5157 } 5158 } 5159 result->sym_out = symp; 5160 return (true); 5161 } 5162 5163 /* 5164 * Search for symbol using SysV hash function. 5165 * obj->buckets is known not to be NULL at this point; the test for this was 5166 * performed with the obj->valid_hash_sysv assignment. 5167 */ 5168 static int 5169 symlook_obj1_sysv(SymLook *req, const Obj_Entry *obj) 5170 { 5171 unsigned long symnum; 5172 Sym_Match_Result matchres; 5173 5174 matchres.sym_out = NULL; 5175 matchres.vsymp = NULL; 5176 matchres.vcount = 0; 5177 5178 for (symnum = obj->buckets[req->hash % obj->nbuckets]; 5179 symnum != STN_UNDEF; symnum = obj->chains[symnum]) { 5180 if (symnum >= obj->nchains) 5181 return (ESRCH); /* Bad object */ 5182 5183 if (matched_symbol(req, obj, &matchres, symnum)) { 5184 req->sym_out = matchres.sym_out; 5185 req->defobj_out = obj; 5186 return (0); 5187 } 5188 } 5189 if (matchres.vcount == 1) { 5190 req->sym_out = matchres.vsymp; 5191 req->defobj_out = obj; 5192 return (0); 5193 } 5194 return (ESRCH); 5195 } 5196 5197 /* Search for symbol using GNU hash function */ 5198 static int 5199 symlook_obj1_gnu(SymLook *req, const Obj_Entry *obj) 5200 { 5201 Elf_Addr bloom_word; 5202 const Elf32_Word *hashval; 5203 Elf32_Word bucket; 5204 Sym_Match_Result matchres; 5205 unsigned int h1, h2; 5206 unsigned long symnum; 5207 5208 matchres.sym_out = NULL; 5209 matchres.vsymp = NULL; 5210 matchres.vcount = 0; 5211 5212 /* Pick right bitmask word from Bloom filter array */ 5213 bloom_word = obj->bloom_gnu[(req->hash_gnu / __ELF_WORD_SIZE) & 5214 obj->maskwords_bm_gnu]; 5215 5216 /* Calculate modulus word size of gnu hash and its derivative */ 5217 h1 = req->hash_gnu & (__ELF_WORD_SIZE - 1); 5218 h2 = ((req->hash_gnu >> obj->shift2_gnu) & (__ELF_WORD_SIZE - 1)); 5219 5220 /* Filter out the "definitely not in set" queries */ 5221 if (((bloom_word >> h1) & (bloom_word >> h2) & 1) == 0) 5222 return (ESRCH); 5223 5224 /* Locate hash chain and corresponding value element*/ 5225 bucket = obj->buckets_gnu[req->hash_gnu % obj->nbuckets_gnu]; 5226 if (bucket == 0) 5227 return (ESRCH); 5228 hashval = &obj->chain_zero_gnu[bucket]; 5229 do { 5230 if (((*hashval ^ req->hash_gnu) >> 1) == 0) { 5231 symnum = hashval - obj->chain_zero_gnu; 5232 if (matched_symbol(req, obj, &matchres, symnum)) { 5233 req->sym_out = matchres.sym_out; 5234 req->defobj_out = obj; 5235 return (0); 5236 } 5237 } 5238 } while ((*hashval++ & 1) == 0); 5239 if (matchres.vcount == 1) { 5240 req->sym_out = matchres.vsymp; 5241 req->defobj_out = obj; 5242 return (0); 5243 } 5244 return (ESRCH); 5245 } 5246 5247 static void 5248 trace_calc_fmts(const char **main_local, const char **fmt1, const char **fmt2) 5249 { 5250 *main_local = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_PROGNAME); 5251 if (*main_local == NULL) 5252 *main_local = ""; 5253 5254 *fmt1 = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_FMT1); 5255 if (*fmt1 == NULL) 5256 *fmt1 = "\t%o => %p (%x)\n"; 5257 5258 *fmt2 = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_FMT2); 5259 if (*fmt2 == NULL) 5260 *fmt2 = "\t%o (%x)\n"; 5261 } 5262 5263 static void 5264 trace_print_obj(Obj_Entry *obj, const char *name, const char *path, 5265 const char *main_local, const char *fmt1, const char *fmt2) 5266 { 5267 const char *fmt; 5268 int c; 5269 5270 if (fmt1 == NULL) 5271 fmt = fmt2; 5272 else 5273 /* XXX bogus */ 5274 fmt = strncmp(name, "lib", 3) == 0 ? fmt1 : fmt2; 5275 5276 while ((c = *fmt++) != '\0') { 5277 switch (c) { 5278 default: 5279 rtld_putchar(c); 5280 continue; 5281 case '\\': 5282 switch (c = *fmt) { 5283 case '\0': 5284 continue; 5285 case 'n': 5286 rtld_putchar('\n'); 5287 break; 5288 case 't': 5289 rtld_putchar('\t'); 5290 break; 5291 } 5292 break; 5293 case '%': 5294 switch (c = *fmt) { 5295 case '\0': 5296 continue; 5297 case '%': 5298 default: 5299 rtld_putchar(c); 5300 break; 5301 case 'A': 5302 rtld_putstr(main_local); 5303 break; 5304 case 'a': 5305 rtld_putstr(obj_main->path); 5306 break; 5307 case 'o': 5308 rtld_putstr(name); 5309 break; 5310 case 'p': 5311 rtld_putstr(path); 5312 break; 5313 case 'x': 5314 rtld_printf("%p", 5315 obj != NULL ? obj->mapbase : NULL); 5316 break; 5317 } 5318 break; 5319 } 5320 ++fmt; 5321 } 5322 } 5323 5324 static void 5325 trace_loaded_objects(Obj_Entry *obj, bool show_preload) 5326 { 5327 const char *fmt1, *fmt2, *main_local; 5328 const char *name, *path; 5329 bool first_spurious, list_containers; 5330 5331 trace_calc_fmts(&main_local, &fmt1, &fmt2); 5332 list_containers = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_ALL) != NULL; 5333 5334 for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 5335 Needed_Entry *needed; 5336 5337 if (obj->marker) 5338 continue; 5339 if (list_containers && obj->needed != NULL) 5340 rtld_printf("%s:\n", obj->path); 5341 for (needed = obj->needed; needed; needed = needed->next) { 5342 if (needed->obj != NULL) { 5343 if (needed->obj->traced && !list_containers) 5344 continue; 5345 needed->obj->traced = true; 5346 path = needed->obj->path; 5347 } else 5348 path = "not found"; 5349 5350 name = obj->strtab + needed->name; 5351 trace_print_obj(needed->obj, name, path, main_local, 5352 fmt1, fmt2); 5353 } 5354 } 5355 5356 if (show_preload) { 5357 if (ld_get_env_var(LD_TRACE_LOADED_OBJECTS_FMT2) == NULL) 5358 fmt2 = "\t%p (%x)\n"; 5359 first_spurious = true; 5360 5361 TAILQ_FOREACH(obj, &obj_list, next) { 5362 if (obj->marker || obj == obj_main || obj->traced) 5363 continue; 5364 5365 if (list_containers && first_spurious) { 5366 rtld_printf("[preloaded]\n"); 5367 first_spurious = false; 5368 } 5369 5370 Name_Entry *fname = STAILQ_FIRST(&obj->names); 5371 name = fname == NULL ? "<unknown>" : fname->name; 5372 trace_print_obj(obj, name, obj->path, main_local, NULL, 5373 fmt2); 5374 } 5375 } 5376 } 5377 5378 /* 5379 * Unload a dlopened object and its dependencies from memory and from 5380 * our data structures. It is assumed that the DAG rooted in the 5381 * object has already been unreferenced, and that the object has a 5382 * reference count of 0. 5383 */ 5384 static void 5385 unload_object(Obj_Entry *root, RtldLockState *lockstate) 5386 { 5387 Obj_Entry marker, *obj, *next; 5388 5389 assert(root->refcount == 0); 5390 5391 /* 5392 * Pass over the DAG removing unreferenced objects from 5393 * appropriate lists. 5394 */ 5395 unlink_object(root); 5396 5397 /* Unmap all objects that are no longer referenced. */ 5398 for (obj = TAILQ_FIRST(&obj_list); obj != NULL; obj = next) { 5399 next = TAILQ_NEXT(obj, next); 5400 if (obj->marker || obj->refcount != 0) 5401 continue; 5402 LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 5403 0, obj->path); 5404 dbg("unloading \"%s\"", obj->path); 5405 /* 5406 * Unlink the object now to prevent new references from 5407 * being acquired while the bind lock is dropped in 5408 * recursive dlclose() invocations. 5409 */ 5410 TAILQ_REMOVE(&obj_list, obj, next); 5411 obj_count--; 5412 5413 if (obj->filtees_loaded) { 5414 if (next != NULL) { 5415 init_marker(&marker); 5416 TAILQ_INSERT_BEFORE(next, &marker, next); 5417 unload_filtees(obj, lockstate); 5418 next = TAILQ_NEXT(&marker, next); 5419 TAILQ_REMOVE(&obj_list, &marker, next); 5420 } else 5421 unload_filtees(obj, lockstate); 5422 } 5423 release_object(obj); 5424 } 5425 } 5426 5427 static void 5428 unlink_object(Obj_Entry *root) 5429 { 5430 Objlist_Entry *elm; 5431 5432 if (root->refcount == 0) { 5433 /* Remove the object from the RTLD_GLOBAL list. */ 5434 objlist_remove(&list_global, root); 5435 5436 /* Remove the object from all objects' DAG lists. */ 5437 STAILQ_FOREACH(elm, &root->dagmembers, link) { 5438 objlist_remove(&elm->obj->dldags, root); 5439 if (elm->obj != root) 5440 unlink_object(elm->obj); 5441 } 5442 } 5443 } 5444 5445 static void 5446 ref_dag(Obj_Entry *root) 5447 { 5448 Objlist_Entry *elm; 5449 5450 assert(root->dag_inited); 5451 STAILQ_FOREACH(elm, &root->dagmembers, link) 5452 elm->obj->refcount++; 5453 } 5454 5455 static void 5456 unref_dag(Obj_Entry *root) 5457 { 5458 Objlist_Entry *elm; 5459 5460 assert(root->dag_inited); 5461 STAILQ_FOREACH(elm, &root->dagmembers, link) 5462 elm->obj->refcount--; 5463 } 5464 5465 /* 5466 * Common code for MD __tls_get_addr(). 5467 */ 5468 static void * 5469 tls_get_addr_slow(struct tcb *tcb, int index, size_t offset, bool locked) 5470 { 5471 struct dtv *newdtv, *dtv; 5472 RtldLockState lockstate; 5473 int to_copy; 5474 5475 dtv = tcb->tcb_dtv; 5476 /* Check dtv generation in case new modules have arrived */ 5477 if (dtv->dtv_gen != tls_dtv_generation) { 5478 if (!locked) 5479 wlock_acquire(rtld_bind_lock, &lockstate); 5480 newdtv = xcalloc(1, sizeof(struct dtv) + tls_max_index * 5481 sizeof(struct dtv_slot)); 5482 to_copy = dtv->dtv_size; 5483 if (to_copy > tls_max_index) 5484 to_copy = tls_max_index; 5485 memcpy(newdtv->dtv_slots, dtv->dtv_slots, to_copy * 5486 sizeof(struct dtv_slot)); 5487 newdtv->dtv_gen = tls_dtv_generation; 5488 newdtv->dtv_size = tls_max_index; 5489 free(dtv); 5490 if (!locked) 5491 lock_release(rtld_bind_lock, &lockstate); 5492 dtv = tcb->tcb_dtv = newdtv; 5493 } 5494 5495 /* Dynamically allocate module TLS if necessary */ 5496 if (dtv->dtv_slots[index - 1].dtvs_tls == 0) { 5497 /* Signal safe, wlock will block out signals. */ 5498 if (!locked) 5499 wlock_acquire(rtld_bind_lock, &lockstate); 5500 if (!dtv->dtv_slots[index - 1].dtvs_tls) 5501 dtv->dtv_slots[index - 1].dtvs_tls = 5502 allocate_module_tls(tcb, index); 5503 if (!locked) 5504 lock_release(rtld_bind_lock, &lockstate); 5505 } 5506 return (dtv->dtv_slots[index - 1].dtvs_tls + offset); 5507 } 5508 5509 void * 5510 tls_get_addr_common(struct tcb *tcb, int index, size_t offset) 5511 { 5512 struct dtv *dtv; 5513 5514 dtv = tcb->tcb_dtv; 5515 /* Check dtv generation in case new modules have arrived */ 5516 if (__predict_true(dtv->dtv_gen == tls_dtv_generation && 5517 dtv->dtv_slots[index - 1].dtvs_tls != 0)) 5518 return (dtv->dtv_slots[index - 1].dtvs_tls + offset); 5519 return (tls_get_addr_slow(tcb, index, offset, false)); 5520 } 5521 5522 static struct tcb * 5523 tcb_from_tcb_list_entry(struct tcb_list_entry *tcbelm) 5524 { 5525 #ifdef TLS_VARIANT_I 5526 return ((struct tcb *)((char *)tcbelm - tcb_list_entry_offset)); 5527 #else 5528 return ((struct tcb *)((char *)tcbelm + tcb_list_entry_offset)); 5529 #endif 5530 } 5531 5532 static struct tcb_list_entry * 5533 tcb_list_entry_from_tcb(struct tcb *tcb) 5534 { 5535 #ifdef TLS_VARIANT_I 5536 return ((struct tcb_list_entry *)((char *)tcb + tcb_list_entry_offset)); 5537 #else 5538 return ((struct tcb_list_entry *)((char *)tcb - tcb_list_entry_offset)); 5539 #endif 5540 } 5541 5542 static void 5543 tcb_list_insert(struct tcb *tcb) 5544 { 5545 struct tcb_list_entry *tcbelm; 5546 5547 tcbelm = tcb_list_entry_from_tcb(tcb); 5548 TAILQ_INSERT_TAIL(&tcb_list, tcbelm, next); 5549 } 5550 5551 static void 5552 tcb_list_remove(struct tcb *tcb) 5553 { 5554 struct tcb_list_entry *tcbelm; 5555 5556 tcbelm = tcb_list_entry_from_tcb(tcb); 5557 TAILQ_REMOVE(&tcb_list, tcbelm, next); 5558 } 5559 5560 #ifdef TLS_VARIANT_I 5561 5562 /* 5563 * Return pointer to allocated TLS block 5564 */ 5565 static void * 5566 get_tls_block_ptr(void *tcb, size_t tcbsize) 5567 { 5568 size_t extra_size, post_size, pre_size, tls_block_size; 5569 size_t tls_init_align; 5570 5571 tls_init_align = MAX(obj_main->tlsalign, 1); 5572 5573 /* Compute fragments sizes. */ 5574 extra_size = tcbsize - TLS_TCB_SIZE; 5575 post_size = calculate_tls_post_size(tls_init_align); 5576 tls_block_size = tcbsize + post_size; 5577 pre_size = roundup2(tls_block_size, tls_init_align) - tls_block_size; 5578 5579 return ((char *)tcb - pre_size - extra_size); 5580 } 5581 5582 /* 5583 * Allocate Static TLS using the Variant I method. 5584 * 5585 * For details on the layout, see lib/libc/gen/tls.c. 5586 * 5587 * NB: rtld's tls_static_space variable includes TLS_TCB_SIZE and post_size as 5588 * it is based on tls_last_offset, and TLS offsets here are really TCB 5589 * offsets, whereas libc's tls_static_space is just the executable's static 5590 * TLS segment. 5591 * 5592 * NB: This differs from NetBSD's ld.elf_so, where TLS offsets are relative to 5593 * the end of the TCB. 5594 */ 5595 void * 5596 allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign) 5597 { 5598 Obj_Entry *obj; 5599 char *tls_block; 5600 struct dtv *dtv; 5601 struct tcb *tcb; 5602 char *addr; 5603 size_t i; 5604 size_t extra_size, maxalign, post_size, pre_size, tls_block_size; 5605 size_t tls_init_align, tls_init_offset, tls_bss_offset; 5606 5607 if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE) 5608 return (oldtcb); 5609 5610 assert(tcbsize >= TLS_TCB_SIZE); 5611 maxalign = MAX(tcbalign, tls_static_max_align); 5612 tls_init_align = MAX(obj_main->tlsalign, 1); 5613 5614 /* Compute fragments sizes. */ 5615 extra_size = tcbsize - TLS_TCB_SIZE; 5616 post_size = calculate_tls_post_size(tls_init_align); 5617 tls_block_size = tcbsize + post_size; 5618 pre_size = roundup2(tls_block_size, tls_init_align) - tls_block_size; 5619 tls_block_size += pre_size + tls_static_space - TLS_TCB_SIZE - 5620 post_size; 5621 5622 /* Allocate whole TLS block */ 5623 tls_block = xmalloc_aligned(tls_block_size, maxalign, 0); 5624 tcb = (struct tcb *)(tls_block + pre_size + extra_size); 5625 5626 if (oldtcb != NULL) { 5627 memcpy(tls_block, get_tls_block_ptr(oldtcb, tcbsize), 5628 tls_static_space); 5629 free(get_tls_block_ptr(oldtcb, tcbsize)); 5630 5631 /* Adjust the DTV. */ 5632 dtv = tcb->tcb_dtv; 5633 for (i = 0; i < dtv->dtv_size; i++) { 5634 if ((uintptr_t)dtv->dtv_slots[i].dtvs_tls >= 5635 (uintptr_t)oldtcb && 5636 (uintptr_t)dtv->dtv_slots[i].dtvs_tls < 5637 (uintptr_t)oldtcb + tls_static_space) { 5638 dtv->dtv_slots[i].dtvs_tls = (char *)tcb + 5639 (dtv->dtv_slots[i].dtvs_tls - 5640 (char *)oldtcb); 5641 } 5642 } 5643 } else { 5644 dtv = xcalloc(1, sizeof(struct dtv) + tls_max_index * 5645 sizeof(struct dtv_slot)); 5646 tcb->tcb_dtv = dtv; 5647 dtv->dtv_gen = tls_dtv_generation; 5648 dtv->dtv_size = tls_max_index; 5649 5650 for (obj = globallist_curr(objs); obj != NULL; 5651 obj = globallist_next(obj)) { 5652 if (obj->tlsoffset == 0) 5653 continue; 5654 tls_init_offset = obj->tlspoffset & (obj->tlsalign - 1); 5655 addr = (char *)tcb + obj->tlsoffset; 5656 if (tls_init_offset > 0) 5657 memset(addr, 0, tls_init_offset); 5658 if (obj->tlsinitsize > 0) { 5659 memcpy(addr + tls_init_offset, obj->tlsinit, 5660 obj->tlsinitsize); 5661 } 5662 if (obj->tlssize > obj->tlsinitsize) { 5663 tls_bss_offset = tls_init_offset + 5664 obj->tlsinitsize; 5665 memset(addr + tls_bss_offset, 0, 5666 obj->tlssize - tls_bss_offset); 5667 } 5668 dtv->dtv_slots[obj->tlsindex - 1].dtvs_tls = addr; 5669 } 5670 } 5671 5672 tcb_list_insert(tcb); 5673 return (tcb); 5674 } 5675 5676 void 5677 free_tls(void *tcb, size_t tcbsize, size_t tcbalign __unused) 5678 { 5679 struct dtv *dtv; 5680 uintptr_t tlsstart, tlsend; 5681 size_t post_size; 5682 size_t i, tls_init_align __unused; 5683 5684 tcb_list_remove(tcb); 5685 5686 assert(tcbsize >= TLS_TCB_SIZE); 5687 tls_init_align = MAX(obj_main->tlsalign, 1); 5688 5689 /* Compute fragments sizes. */ 5690 post_size = calculate_tls_post_size(tls_init_align); 5691 5692 tlsstart = (uintptr_t)tcb + TLS_TCB_SIZE + post_size; 5693 tlsend = (uintptr_t)tcb + tls_static_space; 5694 5695 dtv = ((struct tcb *)tcb)->tcb_dtv; 5696 for (i = 0; i < dtv->dtv_size; i++) { 5697 if (dtv->dtv_slots[i].dtvs_tls != NULL && 5698 ((uintptr_t)dtv->dtv_slots[i].dtvs_tls < tlsstart || 5699 (uintptr_t)dtv->dtv_slots[i].dtvs_tls >= tlsend)) { 5700 free(dtv->dtv_slots[i].dtvs_tls); 5701 } 5702 } 5703 free(dtv); 5704 free(get_tls_block_ptr(tcb, tcbsize)); 5705 } 5706 5707 #endif /* TLS_VARIANT_I */ 5708 5709 #ifdef TLS_VARIANT_II 5710 5711 /* 5712 * Allocate Static TLS using the Variant II method. 5713 */ 5714 void * 5715 allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign) 5716 { 5717 Obj_Entry *obj; 5718 size_t size, ralign; 5719 char *tls_block; 5720 struct dtv *dtv, *olddtv; 5721 struct tcb *tcb; 5722 char *addr; 5723 size_t i; 5724 5725 ralign = tcbalign; 5726 if (tls_static_max_align > ralign) 5727 ralign = tls_static_max_align; 5728 size = roundup(tls_static_space, ralign) + roundup(tcbsize, ralign); 5729 5730 assert(tcbsize >= 2 * sizeof(uintptr_t)); 5731 tls_block = xmalloc_aligned(size, ralign, 0 /* XXX */); 5732 dtv = xcalloc(1, sizeof(struct dtv) + tls_max_index * 5733 sizeof(struct dtv_slot)); 5734 5735 tcb = (struct tcb *)(tls_block + roundup(tls_static_space, ralign)); 5736 tcb->tcb_self = tcb; 5737 tcb->tcb_dtv = dtv; 5738 5739 dtv->dtv_gen = tls_dtv_generation; 5740 dtv->dtv_size = tls_max_index; 5741 5742 if (oldtcb != NULL) { 5743 /* 5744 * Copy the static TLS block over whole. 5745 */ 5746 memcpy((char *)tcb - tls_static_space, 5747 (const char *)oldtcb - tls_static_space, 5748 tls_static_space); 5749 5750 /* 5751 * If any dynamic TLS blocks have been created tls_get_addr(), 5752 * move them over. 5753 */ 5754 olddtv = ((struct tcb *)oldtcb)->tcb_dtv; 5755 for (i = 0; i < olddtv->dtv_size; i++) { 5756 if ((uintptr_t)olddtv->dtv_slots[i].dtvs_tls < 5757 (uintptr_t)oldtcb - size || 5758 (uintptr_t)olddtv->dtv_slots[i].dtvs_tls > 5759 (uintptr_t)oldtcb) { 5760 dtv->dtv_slots[i].dtvs_tls = 5761 olddtv->dtv_slots[i].dtvs_tls; 5762 olddtv->dtv_slots[i].dtvs_tls = NULL; 5763 } 5764 } 5765 5766 /* 5767 * We assume that this block was the one we created with 5768 * allocate_initial_tls(). 5769 */ 5770 free_tls(oldtcb, 2 * sizeof(uintptr_t), sizeof(uintptr_t)); 5771 } else { 5772 for (obj = objs; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 5773 if (obj->marker || obj->tlsoffset == 0) 5774 continue; 5775 addr = (char *)tcb - obj->tlsoffset; 5776 memset(addr + obj->tlsinitsize, 0, obj->tlssize - 5777 obj->tlsinitsize); 5778 if (obj->tlsinit) { 5779 memcpy(addr, obj->tlsinit, obj->tlsinitsize); 5780 obj->static_tls_copied = true; 5781 } 5782 dtv->dtv_slots[obj->tlsindex - 1].dtvs_tls = addr; 5783 } 5784 } 5785 5786 tcb_list_insert(tcb); 5787 return (tcb); 5788 } 5789 5790 void 5791 free_tls(void *tcb, size_t tcbsize __unused, size_t tcbalign) 5792 { 5793 struct dtv *dtv; 5794 size_t size, ralign; 5795 size_t i; 5796 uintptr_t tlsstart, tlsend; 5797 5798 tcb_list_remove(tcb); 5799 5800 /* 5801 * Figure out the size of the initial TLS block so that we can 5802 * find stuff which ___tls_get_addr() allocated dynamically. 5803 */ 5804 ralign = tcbalign; 5805 if (tls_static_max_align > ralign) 5806 ralign = tls_static_max_align; 5807 size = roundup(tls_static_space, ralign); 5808 5809 dtv = ((struct tcb *)tcb)->tcb_dtv; 5810 tlsend = (uintptr_t)tcb; 5811 tlsstart = tlsend - size; 5812 for (i = 0; i < dtv->dtv_size; i++) { 5813 if (dtv->dtv_slots[i].dtvs_tls != NULL && 5814 ((uintptr_t)dtv->dtv_slots[i].dtvs_tls < tlsstart || 5815 (uintptr_t)dtv->dtv_slots[i].dtvs_tls > tlsend)) { 5816 free(dtv->dtv_slots[i].dtvs_tls); 5817 } 5818 } 5819 5820 free((void *)tlsstart); 5821 free(dtv); 5822 } 5823 5824 #endif /* TLS_VARIANT_II */ 5825 5826 /* 5827 * Allocate TLS block for module with given index. 5828 */ 5829 void * 5830 allocate_module_tls(struct tcb *tcb, int index) 5831 { 5832 Obj_Entry *obj; 5833 char *p; 5834 5835 TAILQ_FOREACH(obj, &obj_list, next) { 5836 if (obj->marker) 5837 continue; 5838 if (obj->tlsindex == index) 5839 break; 5840 } 5841 if (obj == NULL) { 5842 _rtld_error("Can't find module with TLS index %d", index); 5843 rtld_die(); 5844 } 5845 5846 if (obj->tls_static) { 5847 #ifdef TLS_VARIANT_I 5848 p = (char *)tcb + obj->tlsoffset; 5849 #else 5850 p = (char *)tcb - obj->tlsoffset; 5851 #endif 5852 return (p); 5853 } 5854 5855 obj->tls_dynamic = true; 5856 5857 p = xmalloc_aligned(obj->tlssize, obj->tlsalign, obj->tlspoffset); 5858 memcpy(p, obj->tlsinit, obj->tlsinitsize); 5859 memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize); 5860 return (p); 5861 } 5862 5863 static bool 5864 allocate_tls_offset_common(size_t *offp, size_t tlssize, size_t tlsalign, 5865 size_t tlspoffset __unused) 5866 { 5867 size_t off; 5868 5869 if (tls_last_offset == 0) 5870 off = calculate_first_tls_offset(tlssize, tlsalign, 5871 tlspoffset); 5872 else 5873 off = calculate_tls_offset(tls_last_offset, tls_last_size, 5874 tlssize, tlsalign, tlspoffset); 5875 5876 *offp = off; 5877 #ifdef TLS_VARIANT_I 5878 off += tlssize; 5879 #endif 5880 5881 /* 5882 * If we have already fixed the size of the static TLS block, we 5883 * must stay within that size. When allocating the static TLS, we 5884 * leave a small amount of space spare to be used for dynamically 5885 * loading modules which use static TLS. 5886 */ 5887 if (tls_static_space != 0) { 5888 if (off > tls_static_space) 5889 return (false); 5890 } else if (tlsalign > tls_static_max_align) { 5891 tls_static_max_align = tlsalign; 5892 } 5893 5894 tls_last_offset = off; 5895 tls_last_size = tlssize; 5896 5897 return (true); 5898 } 5899 5900 bool 5901 allocate_tls_offset(Obj_Entry *obj) 5902 { 5903 if (obj->tls_dynamic) 5904 return (false); 5905 5906 if (obj->tls_static) 5907 return (true); 5908 5909 if (obj->tlssize == 0) { 5910 obj->tls_static = true; 5911 return (true); 5912 } 5913 5914 if (!allocate_tls_offset_common(&obj->tlsoffset, obj->tlssize, 5915 obj->tlsalign, obj->tlspoffset)) 5916 return (false); 5917 5918 obj->tls_static = true; 5919 5920 return (true); 5921 } 5922 5923 void 5924 free_tls_offset(Obj_Entry *obj) 5925 { 5926 /* 5927 * If we were the last thing to allocate out of the static TLS 5928 * block, we give our space back to the 'allocator'. This is a 5929 * simplistic workaround to allow libGL.so.1 to be loaded and 5930 * unloaded multiple times. 5931 */ 5932 size_t off = obj->tlsoffset; 5933 5934 #ifdef TLS_VARIANT_I 5935 off += obj->tlssize; 5936 #endif 5937 if (off == tls_last_offset) { 5938 tls_last_offset -= obj->tlssize; 5939 tls_last_size = 0; 5940 } 5941 } 5942 5943 void * 5944 _rtld_allocate_tls(void *oldtcb, size_t tcbsize, size_t tcbalign) 5945 { 5946 void *ret; 5947 RtldLockState lockstate; 5948 5949 wlock_acquire(rtld_bind_lock, &lockstate); 5950 ret = allocate_tls(globallist_curr(TAILQ_FIRST(&obj_list)), oldtcb, 5951 tcbsize, tcbalign); 5952 lock_release(rtld_bind_lock, &lockstate); 5953 return (ret); 5954 } 5955 5956 void 5957 _rtld_free_tls(void *tcb, size_t tcbsize, size_t tcbalign) 5958 { 5959 RtldLockState lockstate; 5960 5961 wlock_acquire(rtld_bind_lock, &lockstate); 5962 free_tls(tcb, tcbsize, tcbalign); 5963 lock_release(rtld_bind_lock, &lockstate); 5964 } 5965 5966 static void 5967 object_add_name(Obj_Entry *obj, const char *name) 5968 { 5969 Name_Entry *entry; 5970 size_t len; 5971 5972 len = strlen(name); 5973 entry = malloc(sizeof(Name_Entry) + len); 5974 5975 if (entry != NULL) { 5976 strcpy(entry->name, name); 5977 STAILQ_INSERT_TAIL(&obj->names, entry, link); 5978 } 5979 } 5980 5981 static int 5982 object_match_name(const Obj_Entry *obj, const char *name) 5983 { 5984 Name_Entry *entry; 5985 5986 STAILQ_FOREACH(entry, &obj->names, link) { 5987 if (strcmp(name, entry->name) == 0) 5988 return (1); 5989 } 5990 return (0); 5991 } 5992 5993 static Obj_Entry * 5994 locate_dependency(const Obj_Entry *obj, const char *name) 5995 { 5996 const Objlist_Entry *entry; 5997 const Needed_Entry *needed; 5998 5999 STAILQ_FOREACH(entry, &list_main, link) { 6000 if (object_match_name(entry->obj, name)) 6001 return (entry->obj); 6002 } 6003 6004 for (needed = obj->needed; needed != NULL; needed = needed->next) { 6005 if (strcmp(obj->strtab + needed->name, name) == 0 || 6006 (needed->obj != NULL && object_match_name(needed->obj, 6007 name))) { 6008 /* 6009 * If there is DT_NEEDED for the name we are looking 6010 * for, we are all set. Note that object might not be 6011 * found if dependency was not loaded yet, so the 6012 * function can return NULL here. This is expected and 6013 * handled properly by the caller. 6014 */ 6015 return (needed->obj); 6016 } 6017 } 6018 _rtld_error("%s: Unexpected inconsistency: dependency %s not found", 6019 obj->path, name); 6020 rtld_die(); 6021 } 6022 6023 static int 6024 check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj, 6025 const Elf_Vernaux *vna) 6026 { 6027 const Elf_Verdef *vd; 6028 const char *vername; 6029 6030 vername = refobj->strtab + vna->vna_name; 6031 vd = depobj->verdef; 6032 if (vd == NULL) { 6033 _rtld_error("%s: version %s required by %s not defined", 6034 depobj->path, vername, refobj->path); 6035 return (-1); 6036 } 6037 for (;;) { 6038 if (vd->vd_version != VER_DEF_CURRENT) { 6039 _rtld_error( 6040 "%s: Unsupported version %d of Elf_Verdef entry", 6041 depobj->path, vd->vd_version); 6042 return (-1); 6043 } 6044 if (vna->vna_hash == vd->vd_hash) { 6045 const Elf_Verdaux *aux = 6046 (const Elf_Verdaux *)((const char *)vd + 6047 vd->vd_aux); 6048 if (strcmp(vername, depobj->strtab + aux->vda_name) == 6049 0) 6050 return (0); 6051 } 6052 if (vd->vd_next == 0) 6053 break; 6054 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 6055 } 6056 if (vna->vna_flags & VER_FLG_WEAK) 6057 return (0); 6058 _rtld_error("%s: version %s required by %s not found", depobj->path, 6059 vername, refobj->path); 6060 return (-1); 6061 } 6062 6063 static int 6064 rtld_verify_object_versions(Obj_Entry *obj) 6065 { 6066 const Elf_Verneed *vn; 6067 const Elf_Verdef *vd; 6068 const Elf_Verdaux *vda; 6069 const Elf_Vernaux *vna; 6070 const Obj_Entry *depobj; 6071 int maxvernum, vernum; 6072 6073 if (obj->ver_checked) 6074 return (0); 6075 obj->ver_checked = true; 6076 6077 maxvernum = 0; 6078 /* 6079 * Walk over defined and required version records and figure out 6080 * max index used by any of them. Do very basic sanity checking 6081 * while there. 6082 */ 6083 vn = obj->verneed; 6084 while (vn != NULL) { 6085 if (vn->vn_version != VER_NEED_CURRENT) { 6086 _rtld_error( 6087 "%s: Unsupported version %d of Elf_Verneed entry", 6088 obj->path, vn->vn_version); 6089 return (-1); 6090 } 6091 vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux); 6092 for (;;) { 6093 vernum = VER_NEED_IDX(vna->vna_other); 6094 if (vernum > maxvernum) 6095 maxvernum = vernum; 6096 if (vna->vna_next == 0) 6097 break; 6098 vna = (const Elf_Vernaux *)((const char *)vna + 6099 vna->vna_next); 6100 } 6101 if (vn->vn_next == 0) 6102 break; 6103 vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next); 6104 } 6105 6106 vd = obj->verdef; 6107 while (vd != NULL) { 6108 if (vd->vd_version != VER_DEF_CURRENT) { 6109 _rtld_error( 6110 "%s: Unsupported version %d of Elf_Verdef entry", 6111 obj->path, vd->vd_version); 6112 return (-1); 6113 } 6114 vernum = VER_DEF_IDX(vd->vd_ndx); 6115 if (vernum > maxvernum) 6116 maxvernum = vernum; 6117 if (vd->vd_next == 0) 6118 break; 6119 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 6120 } 6121 6122 if (maxvernum == 0) 6123 return (0); 6124 6125 /* 6126 * Store version information in array indexable by version index. 6127 * Verify that object version requirements are satisfied along the 6128 * way. 6129 */ 6130 obj->vernum = maxvernum + 1; 6131 obj->vertab = xcalloc(obj->vernum, sizeof(Ver_Entry)); 6132 6133 vd = obj->verdef; 6134 while (vd != NULL) { 6135 if ((vd->vd_flags & VER_FLG_BASE) == 0) { 6136 vernum = VER_DEF_IDX(vd->vd_ndx); 6137 assert(vernum <= maxvernum); 6138 vda = (const Elf_Verdaux *)((const char *)vd + 6139 vd->vd_aux); 6140 obj->vertab[vernum].hash = vd->vd_hash; 6141 obj->vertab[vernum].name = obj->strtab + vda->vda_name; 6142 obj->vertab[vernum].file = NULL; 6143 obj->vertab[vernum].flags = 0; 6144 } 6145 if (vd->vd_next == 0) 6146 break; 6147 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 6148 } 6149 6150 vn = obj->verneed; 6151 while (vn != NULL) { 6152 depobj = locate_dependency(obj, obj->strtab + vn->vn_file); 6153 if (depobj == NULL) 6154 return (-1); 6155 vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux); 6156 for (;;) { 6157 if (check_object_provided_version(obj, depobj, vna)) 6158 return (-1); 6159 vernum = VER_NEED_IDX(vna->vna_other); 6160 assert(vernum <= maxvernum); 6161 obj->vertab[vernum].hash = vna->vna_hash; 6162 obj->vertab[vernum].name = obj->strtab + vna->vna_name; 6163 obj->vertab[vernum].file = obj->strtab + vn->vn_file; 6164 obj->vertab[vernum].flags = (vna->vna_other & 6165 VER_NEED_HIDDEN) != 0 ? VER_INFO_HIDDEN : 0; 6166 if (vna->vna_next == 0) 6167 break; 6168 vna = (const Elf_Vernaux *)((const char *)vna + 6169 vna->vna_next); 6170 } 6171 if (vn->vn_next == 0) 6172 break; 6173 vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next); 6174 } 6175 return (0); 6176 } 6177 6178 static int 6179 rtld_verify_versions(const Objlist *objlist) 6180 { 6181 Objlist_Entry *entry; 6182 int rc; 6183 6184 rc = 0; 6185 STAILQ_FOREACH(entry, objlist, link) { 6186 /* 6187 * Skip dummy objects or objects that have their version 6188 * requirements already checked. 6189 */ 6190 if (entry->obj->strtab == NULL || entry->obj->vertab != NULL) 6191 continue; 6192 if (rtld_verify_object_versions(entry->obj) == -1) { 6193 rc = -1; 6194 if (ld_tracing == NULL) 6195 break; 6196 } 6197 } 6198 if (rc == 0 || ld_tracing != NULL) 6199 rc = rtld_verify_object_versions(&obj_rtld); 6200 return (rc); 6201 } 6202 6203 const Ver_Entry * 6204 fetch_ventry(const Obj_Entry *obj, unsigned long symnum) 6205 { 6206 Elf_Versym vernum; 6207 6208 if (obj->vertab) { 6209 vernum = VER_NDX(obj->versyms[symnum]); 6210 if (vernum >= obj->vernum) { 6211 _rtld_error("%s: symbol %s has wrong verneed value %d", 6212 obj->path, obj->strtab + symnum, vernum); 6213 } else if (obj->vertab[vernum].hash != 0) { 6214 return (&obj->vertab[vernum]); 6215 } 6216 } 6217 return (NULL); 6218 } 6219 6220 int 6221 _rtld_get_stack_prot(void) 6222 { 6223 return (stack_prot); 6224 } 6225 6226 int 6227 _rtld_is_dlopened(void *arg) 6228 { 6229 Obj_Entry *obj; 6230 RtldLockState lockstate; 6231 int res; 6232 6233 rlock_acquire(rtld_bind_lock, &lockstate); 6234 obj = dlcheck(arg); 6235 if (obj == NULL) 6236 obj = obj_from_addr(arg); 6237 if (obj == NULL) { 6238 _rtld_error("No shared object contains address"); 6239 lock_release(rtld_bind_lock, &lockstate); 6240 return (-1); 6241 } 6242 res = obj->dlopened ? 1 : 0; 6243 lock_release(rtld_bind_lock, &lockstate); 6244 return (res); 6245 } 6246 6247 static int 6248 obj_remap_relro(Obj_Entry *obj, int prot) 6249 { 6250 const Elf_Phdr *ph; 6251 caddr_t relro_page; 6252 size_t relro_size; 6253 6254 for (ph = obj->phdr; ph < obj->phdr + obj->phnum; ph++) { 6255 if (ph->p_type != PT_GNU_RELRO) 6256 continue; 6257 relro_page = obj->relocbase + rtld_trunc_page(ph->p_vaddr); 6258 relro_size = rtld_round_page(ph->p_vaddr + ph->p_memsz) - 6259 rtld_trunc_page(ph->p_vaddr); 6260 if (mprotect(relro_page, relro_size, prot) == -1) { 6261 _rtld_error( 6262 "%s: Cannot set relro protection to %#x: %s", 6263 obj->path, prot, rtld_strerror(errno)); 6264 return (-1); 6265 } 6266 break; 6267 } 6268 return (0); 6269 } 6270 6271 static int 6272 obj_disable_relro(Obj_Entry *obj) 6273 { 6274 return (obj_remap_relro(obj, PROT_READ | PROT_WRITE)); 6275 } 6276 6277 static int 6278 obj_enforce_relro(Obj_Entry *obj) 6279 { 6280 return (obj_remap_relro(obj, PROT_READ)); 6281 } 6282 6283 static void 6284 map_stacks_exec(RtldLockState *lockstate) 6285 { 6286 void (*thr_map_stacks_exec)(void); 6287 6288 if ((max_stack_flags & PF_X) == 0 || (stack_prot & PROT_EXEC) != 0) 6289 return; 6290 thr_map_stacks_exec = (void (*)(void))( 6291 uintptr_t)get_program_var_addr("__pthread_map_stacks_exec", 6292 lockstate); 6293 if (thr_map_stacks_exec != NULL) { 6294 stack_prot |= PROT_EXEC; 6295 thr_map_stacks_exec(); 6296 } 6297 } 6298 6299 static void 6300 distribute_static_tls(Objlist *list) 6301 { 6302 struct tcb_list_entry *tcbelm; 6303 Objlist_Entry *objelm; 6304 struct tcb *tcb; 6305 Obj_Entry *obj; 6306 char *tlsbase; 6307 6308 STAILQ_FOREACH(objelm, list, link) { 6309 obj = objelm->obj; 6310 if (obj->marker || !obj->tls_static || obj->static_tls_copied) 6311 continue; 6312 TAILQ_FOREACH(tcbelm, &tcb_list, next) { 6313 tcb = tcb_from_tcb_list_entry(tcbelm); 6314 #ifdef TLS_VARIANT_I 6315 tlsbase = (char *)tcb + obj->tlsoffset; 6316 #else 6317 tlsbase = (char *)tcb - obj->tlsoffset; 6318 #endif 6319 memcpy(tlsbase, obj->tlsinit, obj->tlsinitsize); 6320 memset(tlsbase + obj->tlsinitsize, 0, 6321 obj->tlssize - obj->tlsinitsize); 6322 } 6323 obj->static_tls_copied = true; 6324 } 6325 } 6326 6327 void 6328 symlook_init(SymLook *dst, const char *name) 6329 { 6330 bzero(dst, sizeof(*dst)); 6331 dst->name = name; 6332 dst->hash = elf_hash(name); 6333 dst->hash_gnu = gnu_hash(name); 6334 } 6335 6336 static void 6337 symlook_init_from_req(SymLook *dst, const SymLook *src) 6338 { 6339 dst->name = src->name; 6340 dst->hash = src->hash; 6341 dst->hash_gnu = src->hash_gnu; 6342 dst->ventry = src->ventry; 6343 dst->flags = src->flags; 6344 dst->defobj_out = NULL; 6345 dst->sym_out = NULL; 6346 dst->lockstate = src->lockstate; 6347 dst->donelist_mem = NULL; 6348 } 6349 6350 static int 6351 open_binary_fd(const char *argv0, bool search_in_path, const char **binpath_res) 6352 { 6353 char *binpath, *pathenv, *pe, *res1; 6354 const char *res; 6355 int fd; 6356 6357 binpath = NULL; 6358 res = NULL; 6359 if (search_in_path && strchr(argv0, '/') == NULL) { 6360 binpath = xmalloc(PATH_MAX); 6361 pathenv = getenv("PATH"); 6362 if (pathenv == NULL) { 6363 _rtld_error("-p and no PATH environment variable"); 6364 rtld_die(); 6365 } 6366 pathenv = strdup(pathenv); 6367 if (pathenv == NULL) { 6368 _rtld_error("Cannot allocate memory"); 6369 rtld_die(); 6370 } 6371 fd = -1; 6372 errno = ENOENT; 6373 while ((pe = strsep(&pathenv, ":")) != NULL) { 6374 if (strlcpy(binpath, pe, PATH_MAX) >= PATH_MAX) 6375 continue; 6376 if (binpath[0] != '\0' && 6377 strlcat(binpath, "/", PATH_MAX) >= PATH_MAX) 6378 continue; 6379 if (strlcat(binpath, argv0, PATH_MAX) >= PATH_MAX) 6380 continue; 6381 fd = open(binpath, O_RDONLY | O_CLOEXEC | O_VERIFY); 6382 if (fd != -1 || errno != ENOENT) { 6383 res = binpath; 6384 break; 6385 } 6386 } 6387 free(pathenv); 6388 } else { 6389 fd = open(argv0, O_RDONLY | O_CLOEXEC | O_VERIFY); 6390 res = argv0; 6391 } 6392 6393 if (fd == -1) { 6394 _rtld_error("Cannot open %s: %s", argv0, rtld_strerror(errno)); 6395 rtld_die(); 6396 } 6397 if (res != NULL && res[0] != '/') { 6398 res1 = xmalloc(PATH_MAX); 6399 if (realpath(res, res1) != NULL) { 6400 if (res != argv0) 6401 free(__DECONST(char *, res)); 6402 res = res1; 6403 } else { 6404 free(res1); 6405 } 6406 } 6407 *binpath_res = res; 6408 return (fd); 6409 } 6410 6411 /* 6412 * Parse a set of command-line arguments. 6413 */ 6414 static int 6415 parse_args(char *argv[], int argc, bool *use_pathp, int *fdp, 6416 const char **argv0, bool *dir_ignore) 6417 { 6418 const char *arg; 6419 char machine[64]; 6420 size_t sz; 6421 int arglen, fd, i, j, mib[2]; 6422 char opt; 6423 bool seen_b, seen_f; 6424 6425 dbg("Parsing command-line arguments"); 6426 *use_pathp = false; 6427 *fdp = -1; 6428 *dir_ignore = false; 6429 seen_b = seen_f = false; 6430 6431 for (i = 1; i < argc; i++) { 6432 arg = argv[i]; 6433 dbg("argv[%d]: '%s'", i, arg); 6434 6435 /* 6436 * rtld arguments end with an explicit "--" or with the first 6437 * non-prefixed argument. 6438 */ 6439 if (strcmp(arg, "--") == 0) { 6440 i++; 6441 break; 6442 } 6443 if (arg[0] != '-') 6444 break; 6445 6446 /* 6447 * All other arguments are single-character options that can 6448 * be combined, so we need to search through `arg` for them. 6449 */ 6450 arglen = strlen(arg); 6451 for (j = 1; j < arglen; j++) { 6452 opt = arg[j]; 6453 if (opt == 'h') { 6454 print_usage(argv[0]); 6455 _exit(0); 6456 } else if (opt == 'b') { 6457 if (seen_f) { 6458 _rtld_error("Both -b and -f specified"); 6459 rtld_die(); 6460 } 6461 if (j != arglen - 1) { 6462 _rtld_error("Invalid options: %s", arg); 6463 rtld_die(); 6464 } 6465 i++; 6466 *argv0 = argv[i]; 6467 seen_b = true; 6468 break; 6469 } else if (opt == 'd') { 6470 *dir_ignore = true; 6471 } else if (opt == 'f') { 6472 if (seen_b) { 6473 _rtld_error("Both -b and -f specified"); 6474 rtld_die(); 6475 } 6476 6477 /* 6478 * -f XX can be used to specify a 6479 * descriptor for the binary named at 6480 * the command line (i.e., the later 6481 * argument will specify the process 6482 * name but the descriptor is what 6483 * will actually be executed). 6484 * 6485 * -f must be the last option in the 6486 * group, e.g., -abcf <fd>. 6487 */ 6488 if (j != arglen - 1) { 6489 _rtld_error("Invalid options: %s", arg); 6490 rtld_die(); 6491 } 6492 i++; 6493 fd = parse_integer(argv[i]); 6494 if (fd == -1) { 6495 _rtld_error( 6496 "Invalid file descriptor: '%s'", 6497 argv[i]); 6498 rtld_die(); 6499 } 6500 *fdp = fd; 6501 seen_f = true; 6502 break; 6503 } else if (opt == 'o') { 6504 struct ld_env_var_desc *l; 6505 char *n, *v; 6506 u_int ll; 6507 6508 if (j != arglen - 1) { 6509 _rtld_error("Invalid options: %s", arg); 6510 rtld_die(); 6511 } 6512 i++; 6513 n = argv[i]; 6514 v = strchr(n, '='); 6515 if (v == NULL) { 6516 _rtld_error("No '=' in -o parameter"); 6517 rtld_die(); 6518 } 6519 for (ll = 0; ll < nitems(ld_env_vars); ll++) { 6520 l = &ld_env_vars[ll]; 6521 if (v - n == (ptrdiff_t)strlen(l->n) && 6522 strncmp(n, l->n, v - n) == 0) { 6523 l->val = v + 1; 6524 break; 6525 } 6526 } 6527 if (ll == nitems(ld_env_vars)) { 6528 _rtld_error("Unknown LD_ option %s", n); 6529 rtld_die(); 6530 } 6531 } else if (opt == 'p') { 6532 *use_pathp = true; 6533 } else if (opt == 'u') { 6534 u_int ll; 6535 6536 for (ll = 0; ll < nitems(ld_env_vars); ll++) 6537 ld_env_vars[ll].val = NULL; 6538 } else if (opt == 'v') { 6539 machine[0] = '\0'; 6540 mib[0] = CTL_HW; 6541 mib[1] = HW_MACHINE; 6542 sz = sizeof(machine); 6543 sysctl(mib, nitems(mib), machine, &sz, NULL, 0); 6544 ld_elf_hints_path = ld_get_env_var( 6545 LD_ELF_HINTS_PATH); 6546 set_ld_elf_hints_path(); 6547 rtld_printf( 6548 "FreeBSD ld-elf.so.1 %s\n" 6549 "FreeBSD_version %d\n" 6550 "Default lib path %s\n" 6551 "Hints lib path %s\n" 6552 "Env prefix %s\n" 6553 "Default hint file %s\n" 6554 "Hint file %s\n" 6555 "libmap file %s\n" 6556 "Optional static TLS size %zd bytes\n", 6557 machine, __FreeBSD_version, 6558 ld_standard_library_path, gethints(false), 6559 ld_env_prefix, ld_elf_hints_default, 6560 ld_elf_hints_path, ld_path_libmap_conf, 6561 ld_static_tls_extra); 6562 _exit(0); 6563 } else { 6564 _rtld_error("Invalid argument: '%s'", arg); 6565 print_usage(argv[0]); 6566 rtld_die(); 6567 } 6568 } 6569 } 6570 6571 if (!seen_b) 6572 *argv0 = argv[i]; 6573 return (i); 6574 } 6575 6576 /* 6577 * Parse a file descriptor number without pulling in more of libc (e.g. atoi). 6578 */ 6579 static int 6580 parse_integer(const char *str) 6581 { 6582 int radix; 6583 const char *orig; 6584 int n, val; 6585 char c; 6586 6587 if (str[0] == '0') { 6588 if (str[1] == 'x') { 6589 str += 2; 6590 radix = 16; 6591 } else if (str[1] == 'b') { 6592 str += 2; 6593 radix = 2; 6594 } else { 6595 str += 1; 6596 radix = 8; 6597 } 6598 } else { 6599 radix = 10; 6600 } 6601 orig = str; 6602 n = 0; 6603 for (c = *str; c != '\0'; c = *++str) { 6604 if (c >= '0' && c <= '9') 6605 val = c - '0'; 6606 else if (c >= 'a' && c <= 'f') 6607 val = c - 'a' + 10; 6608 else if (c >= 'A' && c <= 'F') 6609 val = c - 'A' + 10; 6610 else 6611 return (-1); 6612 if (val >= radix) 6613 return (-1); 6614 6615 if (n > INT_MAX / radix) 6616 return (-1); 6617 n *= radix; 6618 if (n > INT_MAX - val) 6619 return (-1); 6620 n += val; 6621 } 6622 6623 /* 6624 * Make sure we actually parsed something. 6625 * Allow for lone '0'. 6626 */ 6627 if (str == orig && radix != 8) 6628 return (-1); 6629 return (n); 6630 } 6631 6632 static void 6633 print_usage(const char *argv0) 6634 { 6635 rtld_printf( 6636 "Usage: %s [-h] [-b <exe>] [-d] [-f <FD>] [-p] [--] <binary> [<args>]\n" 6637 "\n" 6638 "Options:\n" 6639 " -h Display this help message\n" 6640 " -b <exe> Execute <exe> instead of <binary>, arg0 is <binary>\n" 6641 " -d Ignore lack of exec permissions for the binary\n" 6642 " -f <FD> Execute <FD> instead of searching for <binary>\n" 6643 " -o <OPT>=<VAL> Set LD_<OPT> to <VAL>, without polluting env\n" 6644 " -p Search in PATH for named binary\n" 6645 " -u Ignore LD_ environment variables\n" 6646 " -v Display identification information\n" 6647 " -- End of RTLD options\n" 6648 " <binary> Name of process to execute\n" 6649 " <args> Arguments to the executed process\n", 6650 argv0); 6651 } 6652 6653 #define AUXFMT(at, xfmt) [at] = { .name = #at, .fmt = xfmt } 6654 static const struct auxfmt { 6655 const char *name; 6656 const char *fmt; 6657 } auxfmts[] = { 6658 AUXFMT(AT_NULL, NULL), 6659 AUXFMT(AT_IGNORE, NULL), 6660 AUXFMT(AT_EXECFD, "%ld"), 6661 AUXFMT(AT_PHDR, "%p"), 6662 AUXFMT(AT_PHENT, "%lu"), 6663 AUXFMT(AT_PHNUM, "%lu"), 6664 AUXFMT(AT_PAGESZ, "%lu"), 6665 AUXFMT(AT_BASE, "%#lx"), 6666 AUXFMT(AT_FLAGS, "%#lx"), 6667 AUXFMT(AT_ENTRY, "%p"), 6668 AUXFMT(AT_NOTELF, NULL), 6669 AUXFMT(AT_UID, "%ld"), 6670 AUXFMT(AT_EUID, "%ld"), 6671 AUXFMT(AT_GID, "%ld"), 6672 AUXFMT(AT_EGID, "%ld"), 6673 AUXFMT(AT_EXECPATH, "%s"), 6674 AUXFMT(AT_CANARY, "%p"), 6675 AUXFMT(AT_CANARYLEN, "%lu"), 6676 AUXFMT(AT_OSRELDATE, "%lu"), 6677 AUXFMT(AT_NCPUS, "%lu"), 6678 AUXFMT(AT_PAGESIZES, "%p"), 6679 AUXFMT(AT_PAGESIZESLEN, "%lu"), 6680 AUXFMT(AT_TIMEKEEP, "%p"), 6681 AUXFMT(AT_STACKPROT, "%#lx"), 6682 AUXFMT(AT_EHDRFLAGS, "%#lx"), 6683 AUXFMT(AT_HWCAP, "%#lx"), 6684 AUXFMT(AT_HWCAP2, "%#lx"), 6685 AUXFMT(AT_BSDFLAGS, "%#lx"), 6686 AUXFMT(AT_ARGC, "%lu"), 6687 AUXFMT(AT_ARGV, "%p"), 6688 AUXFMT(AT_ENVC, "%p"), 6689 AUXFMT(AT_ENVV, "%p"), 6690 AUXFMT(AT_PS_STRINGS, "%p"), 6691 AUXFMT(AT_FXRNG, "%p"), 6692 AUXFMT(AT_KPRELOAD, "%p"), 6693 AUXFMT(AT_USRSTACKBASE, "%#lx"), 6694 AUXFMT(AT_USRSTACKLIM, "%#lx"), 6695 /* AT_CHERI_STATS */ 6696 AUXFMT(AT_HWCAP3, "%#lx"), 6697 AUXFMT(AT_HWCAP4, "%#lx"), 6698 6699 }; 6700 6701 static bool 6702 is_ptr_fmt(const char *fmt) 6703 { 6704 char last; 6705 6706 last = fmt[strlen(fmt) - 1]; 6707 return (last == 'p' || last == 's'); 6708 } 6709 6710 static void 6711 dump_auxv(Elf_Auxinfo **aux_info) 6712 { 6713 Elf_Auxinfo *auxp; 6714 const struct auxfmt *fmt; 6715 int i; 6716 6717 for (i = 0; i < AT_COUNT; i++) { 6718 auxp = aux_info[i]; 6719 if (auxp == NULL) 6720 continue; 6721 fmt = &auxfmts[i]; 6722 if (fmt->fmt == NULL) 6723 continue; 6724 rtld_fdprintf(STDOUT_FILENO, "%s:\t", fmt->name); 6725 if (is_ptr_fmt(fmt->fmt)) { 6726 rtld_fdprintfx(STDOUT_FILENO, fmt->fmt, 6727 auxp->a_un.a_ptr); 6728 } else { 6729 rtld_fdprintfx(STDOUT_FILENO, fmt->fmt, 6730 auxp->a_un.a_val); 6731 } 6732 rtld_fdprintf(STDOUT_FILENO, "\n"); 6733 } 6734 } 6735 6736 const char * 6737 rtld_get_var(const char *name) 6738 { 6739 const struct ld_env_var_desc *lvd; 6740 u_int i; 6741 6742 for (i = 0; i < nitems(ld_env_vars); i++) { 6743 lvd = &ld_env_vars[i]; 6744 if (strcmp(lvd->n, name) == 0) 6745 return (lvd->val); 6746 } 6747 return (NULL); 6748 } 6749 6750 static void 6751 rtld_recalc_dangerous_ld_env(void) 6752 { 6753 /* 6754 * Never reset dangerous_ld_env back to false if rtld was ever 6755 * contaminated with it set to true. 6756 */ 6757 dangerous_ld_env |= libmap_disable || libmap_override != NULL || 6758 ld_library_path != NULL || ld_preload != NULL || 6759 ld_elf_hints_path != NULL || ld_loadfltr || !ld_dynamic_weak || 6760 ld_get_env_var(LD_STATIC_TLS_EXTRA) != NULL; 6761 } 6762 6763 static void 6764 rtld_recalc_debug(const char *ld_debug) 6765 { 6766 if (ld_debug != NULL && *ld_debug != '\0') 6767 debug = 1; 6768 } 6769 6770 static void 6771 rtld_set_var_debug(struct ld_env_var_desc *lvd) 6772 { 6773 rtld_recalc_debug(lvd->val); 6774 } 6775 6776 static void 6777 rtld_set_var_library_path(struct ld_env_var_desc *lvd) 6778 { 6779 ld_library_path = lvd->val; 6780 } 6781 6782 static void 6783 rtld_set_var_library_path_fds(struct ld_env_var_desc *lvd) 6784 { 6785 ld_library_dirs = lvd->val; 6786 } 6787 6788 static void 6789 rtld_recalc_path_rpath(const char *library_path_rpath) 6790 { 6791 if (library_path_rpath != NULL) { 6792 if (library_path_rpath[0] == 'y' || 6793 library_path_rpath[0] == 'Y' || 6794 library_path_rpath[0] == '1') 6795 ld_library_path_rpath = true; 6796 else 6797 ld_library_path_rpath = false; 6798 } else { 6799 ld_library_path_rpath = false; 6800 } 6801 } 6802 6803 static void 6804 rtld_set_var_library_path_rpath(struct ld_env_var_desc *lvd) 6805 { 6806 rtld_recalc_path_rpath(lvd->val); 6807 } 6808 6809 static void 6810 rtld_recalc_bind_not(const char *bind_not_val) 6811 { 6812 if (ld_bind_now == NULL) 6813 ld_bind_not = bind_not_val != NULL; 6814 } 6815 6816 static void 6817 rtld_set_var_bind_now(struct ld_env_var_desc *lvd) 6818 { 6819 ld_bind_now = lvd->val; 6820 rtld_recalc_bind_not(ld_get_env_var(LD_BIND_NOT)); 6821 } 6822 6823 static void 6824 rtld_set_var_bind_not(struct ld_env_var_desc *lvd) 6825 { 6826 rtld_recalc_bind_not(lvd->val); 6827 } 6828 6829 static void 6830 rtld_set_var_dynamic_weak(struct ld_env_var_desc *lvd) 6831 { 6832 ld_dynamic_weak = lvd->val == NULL; 6833 } 6834 6835 static void 6836 rtld_set_var_loadfltr(struct ld_env_var_desc *lvd) 6837 { 6838 ld_loadfltr = lvd->val != NULL; 6839 } 6840 6841 static void 6842 rtld_set_var_libmap_disable(struct ld_env_var_desc *lvd) 6843 { 6844 libmap_disable = lvd->val != NULL; 6845 } 6846 6847 int 6848 rtld_set_var(const char *name, const char *val) 6849 { 6850 RtldLockState lockstate; 6851 struct ld_env_var_desc *lvd; 6852 u_int i; 6853 int error; 6854 6855 error = ENOENT; 6856 wlock_acquire(rtld_bind_lock, &lockstate); 6857 for (i = 0; i < nitems(ld_env_vars); i++) { 6858 lvd = &ld_env_vars[i]; 6859 if (strcmp(lvd->n, name) != 0) 6860 continue; 6861 if (!lvd->can_update || (lvd->unsecure && !trust)) { 6862 error = EPERM; 6863 break; 6864 } 6865 if (lvd->owned) 6866 free(__DECONST(char *, lvd->val)); 6867 if (val != NULL) 6868 lvd->val = xstrdup(val); 6869 else 6870 lvd->val = NULL; 6871 lvd->owned = true; 6872 if (lvd->on_update != NULL) 6873 lvd->on_update(lvd); 6874 error = 0; 6875 break; 6876 } 6877 if (error == 0) 6878 rtld_recalc_dangerous_ld_env(); 6879 lock_release(rtld_bind_lock, &lockstate); 6880 return (error); 6881 } 6882 6883 /* 6884 * Overrides for libc_pic-provided functions. 6885 */ 6886 6887 int 6888 __getosreldate(void) 6889 { 6890 size_t len; 6891 int oid[2]; 6892 int error, osrel; 6893 6894 if (osreldate != 0) 6895 return (osreldate); 6896 6897 oid[0] = CTL_KERN; 6898 oid[1] = KERN_OSRELDATE; 6899 osrel = 0; 6900 len = sizeof(osrel); 6901 error = sysctl(oid, 2, &osrel, &len, NULL, 0); 6902 if (error == 0 && osrel > 0 && len == sizeof(osrel)) 6903 osreldate = osrel; 6904 return (osreldate); 6905 } 6906 const char * 6907 rtld_strerror(int errnum) 6908 { 6909 if (errnum < 0 || errnum >= sys_nerr) 6910 return ("Unknown error"); 6911 return (sys_errlist[errnum]); 6912 } 6913 6914 char * 6915 getenv(const char *name) 6916 { 6917 return (__DECONST(char *, rtld_get_env_val(environ, name, 6918 strlen(name)))); 6919 } 6920 6921 extern int _rtld_version__FreeBSD_version __exported; 6922 int _rtld_version__FreeBSD_version = __FreeBSD_version; 6923 6924 extern char _rtld_version_laddr_offset __exported; 6925 char _rtld_version_laddr_offset; 6926 6927 extern char _rtld_version_dlpi_tls_data __exported; 6928 char _rtld_version_dlpi_tls_data; 6929