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 void unlink_object(Obj_Entry *); 182 static void unload_object(Obj_Entry *, RtldLockState *lockstate); 183 static void unref_dag(Obj_Entry *); 184 static void ref_dag(Obj_Entry *); 185 static char *origin_subst_one(Obj_Entry *, char *, const char *, const char *, 186 bool); 187 static char *origin_subst(Obj_Entry *, const char *); 188 static bool obj_resolve_origin(Obj_Entry *obj); 189 static void preinit_main(void); 190 static void rtld_recalc_bind_not(const char *); 191 static void rtld_recalc_dangerous_ld_env(void); 192 static void rtld_recalc_debug(const char *); 193 static void rtld_recalc_path_rpath(const char *); 194 static int rtld_verify_versions(const Objlist *); 195 static int rtld_verify_object_versions(Obj_Entry *); 196 static void object_add_name(Obj_Entry *, const char *); 197 static int object_match_name(const Obj_Entry *, const char *); 198 static void ld_utrace_log(int, void *, void *, size_t, int, const char *); 199 static void rtld_fill_dl_phdr_info(const Obj_Entry *obj, 200 struct dl_phdr_info *phdr_info); 201 static uint32_t gnu_hash(const char *); 202 static bool matched_symbol(SymLook *, const Obj_Entry *, Sym_Match_Result *, 203 const unsigned long); 204 205 struct ld_env_var_desc; 206 static void rtld_set_var_bind_not(struct ld_env_var_desc *lvd); 207 static void rtld_set_var_bind_now(struct ld_env_var_desc *lvd); 208 static void rtld_set_var_debug(struct ld_env_var_desc *lvd); 209 static void rtld_set_var_dynamic_weak(struct ld_env_var_desc *lvd); 210 static void rtld_set_var_libmap_disable(struct ld_env_var_desc *lvd); 211 static void rtld_set_var_library_path(struct ld_env_var_desc *lvd); 212 static void rtld_set_var_library_path_fds(struct ld_env_var_desc *lvd); 213 static void rtld_set_var_library_path_rpath(struct ld_env_var_desc *lvd); 214 static void rtld_set_var_loadfltr(struct ld_env_var_desc *lvd); 215 216 void r_debug_state(struct r_debug *, struct link_map *) __noinline __exported; 217 void _r_debug_postinit(struct link_map *) __noinline __exported; 218 219 int __sys_openat(int, const char *, int, ...); 220 221 /* 222 * Data declarations. 223 */ 224 struct r_debug r_debug __exported; /* for GDB; */ 225 static bool libmap_disable; /* Disable libmap */ 226 static bool ld_loadfltr; /* Immediate filters processing */ 227 static const char *libmap_override; /* Maps to use in addition to libmap.conf */ 228 static bool trust; /* False for setuid and setgid programs */ 229 static bool dangerous_ld_env; /* True if environment variables have been 230 used to affect the libraries loaded */ 231 bool ld_bind_not; /* Disable PLT update */ 232 static const char *ld_bind_now; /* Environment variable for immediate binding */ 233 static bool ld_dynamic_weak = true; /* True if non-weak definition overrides 234 weak definition */ 235 static const char *ld_library_path; /* Environment variable for search path */ 236 static const char 237 *ld_library_dirs; /* Environment variable for library descriptors */ 238 static const char *ld_preload; /* Environment variable for libraries to 239 load first */ 240 static const char *ld_preload_fds; /* Environment variable for libraries 241 represented by descriptors */ 242 static const char 243 *ld_elf_hints_path; /* Environment variable for alternative hints path */ 244 static const char *ld_tracing; /* Called from ldd to print libs */ 245 static const char *ld_utrace; /* Use utrace() to log events. */ 246 static struct obj_entry_q obj_list; /* Queue of all loaded objects */ 247 static Obj_Entry *obj_main; /* The main program shared object */ 248 static Obj_Entry obj_rtld; /* The dynamic linker shared object */ 249 static unsigned int obj_count; /* Number of objects in obj_list */ 250 static unsigned int obj_loads; /* Number of loads of objects (gen count) */ 251 size_t ld_static_tls_extra = /* Static TLS extra space (bytes) */ 252 RTLD_STATIC_TLS_EXTRA; 253 254 static Objlist list_global = /* Objects dlopened with RTLD_GLOBAL */ 255 STAILQ_HEAD_INITIALIZER(list_global); 256 static Objlist list_main = /* Objects loaded at program startup */ 257 STAILQ_HEAD_INITIALIZER(list_main); 258 static Objlist list_fini = /* Objects needing fini() calls */ 259 STAILQ_HEAD_INITIALIZER(list_fini); 260 261 Elf_Sym sym_zero; /* For resolving undefined weak refs. */ 262 263 #define GDB_STATE(s, m) \ 264 r_debug.r_state = s; \ 265 r_debug_state(&r_debug, m); 266 267 extern Elf_Dyn _DYNAMIC; 268 #pragma weak _DYNAMIC 269 270 int dlclose(void *) __exported; 271 char *dlerror(void) __exported; 272 void *dlopen(const char *, int) __exported; 273 void *fdlopen(int, int) __exported; 274 void *dlsym(void *, const char *) __exported; 275 dlfunc_t dlfunc(void *, const char *) __exported; 276 void *dlvsym(void *, const char *, const char *) __exported; 277 int dladdr(const void *, Dl_info *) __exported; 278 void dllockinit(void *, void *(*)(void *), void (*)(void *), void (*)(void *), 279 void (*)(void *), void (*)(void *), void (*)(void *)) __exported; 280 int dlinfo(void *, int, void *) __exported; 281 int _dl_iterate_phdr_locked(__dl_iterate_hdr_callback, void *) __exported; 282 int dl_iterate_phdr(__dl_iterate_hdr_callback, void *) __exported; 283 int _rtld_addr_phdr(const void *, struct dl_phdr_info *) __exported; 284 int _rtld_get_stack_prot(void) __exported; 285 int _rtld_is_dlopened(void *) __exported; 286 void _rtld_error(const char *, ...) __exported; 287 const char *rtld_get_var(const char *name) __exported; 288 int rtld_set_var(const char *name, const char *val) __exported; 289 290 /* Only here to fix -Wmissing-prototypes warnings */ 291 int __getosreldate(void); 292 func_ptr_type _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp); 293 Elf_Addr _rtld_bind(Obj_Entry *obj, Elf_Size reloff); 294 295 int npagesizes; 296 static int osreldate; 297 size_t *pagesizes; 298 size_t page_size; 299 300 static int stack_prot = PROT_READ | PROT_WRITE | PROT_EXEC; 301 static int max_stack_flags; 302 303 /* 304 * Global declarations normally provided by crt1. The dynamic linker is 305 * not built with crt1, so we have to provide them ourselves. 306 */ 307 char *__progname; 308 char **environ; 309 310 /* 311 * Used to pass argc, argv to init functions. 312 */ 313 int main_argc; 314 char **main_argv; 315 316 /* 317 * Globals to control TLS allocation. 318 */ 319 size_t tls_last_offset; /* Static TLS offset of last module */ 320 size_t tls_last_size; /* Static TLS size of last module */ 321 size_t tls_static_space; /* Static TLS space allocated */ 322 static size_t tls_static_max_align; 323 Elf_Addr tls_dtv_generation = 1; /* Used to detect when dtv size changes */ 324 int tls_max_index = 1; /* Largest module index allocated */ 325 326 static TAILQ_HEAD(, tcb_list_entry) tcb_list = 327 TAILQ_HEAD_INITIALIZER(tcb_list); 328 static size_t tcb_list_entry_offset; 329 330 static bool ld_library_path_rpath = false; 331 bool ld_fast_sigblock = false; 332 333 /* 334 * Globals for path names, and such 335 */ 336 const char *ld_elf_hints_default = _PATH_ELF_HINTS; 337 const char *ld_path_libmap_conf = _PATH_LIBMAP_CONF; 338 const char *ld_path_rtld = _PATH_RTLD; 339 const char *ld_standard_library_path = STANDARD_LIBRARY_PATH; 340 const char *ld_env_prefix = LD_; 341 342 static void (*rtld_exit_ptr)(void); 343 344 /* 345 * Fill in a DoneList with an allocation large enough to hold all of 346 * the currently-loaded objects. Keep this as a macro since it calls 347 * alloca and we want that to occur within the scope of the caller. 348 */ 349 #define donelist_init(dlp) \ 350 ((dlp)->objs = alloca(obj_count * sizeof(dlp)->objs[0]), \ 351 assert((dlp)->objs != NULL), (dlp)->num_alloc = obj_count, \ 352 (dlp)->num_used = 0) 353 354 #define LD_UTRACE(e, h, mb, ms, r, n) \ 355 do { \ 356 if (ld_utrace != NULL) \ 357 ld_utrace_log(e, h, mb, ms, r, n); \ 358 } while (0) 359 360 static void 361 ld_utrace_log(int event, void *handle, void *mapbase, size_t mapsize, 362 int refcnt, const char *name) 363 { 364 struct utrace_rtld ut; 365 static const char rtld_utrace_sig[RTLD_UTRACE_SIG_SZ] __nonstring = 366 RTLD_UTRACE_SIG; 367 368 memset(&ut, 0, sizeof(ut)); /* clear holes */ 369 memcpy(ut.sig, rtld_utrace_sig, sizeof(ut.sig)); 370 ut.event = event; 371 ut.handle = handle; 372 ut.mapbase = mapbase; 373 ut.mapsize = mapsize; 374 ut.refcnt = refcnt; 375 if (name != NULL) 376 strlcpy(ut.name, name, sizeof(ut.name)); 377 utrace(&ut, sizeof(ut)); 378 } 379 380 struct ld_env_var_desc { 381 const char *const n; 382 const char *val; 383 const bool unsecure : 1; 384 const bool can_update : 1; 385 bool owned : 1; 386 void (*const on_update)(struct ld_env_var_desc *); 387 }; 388 #define LD_ENV_DESC(var, unsec, ...) \ 389 [LD_##var] = { .n = #var, .unsecure = unsec, __VA_ARGS__ } 390 391 static struct ld_env_var_desc ld_env_vars[] = { 392 LD_ENV_DESC(BIND_NOW, false, .can_update = true, 393 .on_update = rtld_set_var_bind_now), 394 LD_ENV_DESC(PRELOAD, true), 395 LD_ENV_DESC(LIBMAP, true), 396 LD_ENV_DESC(LIBRARY_PATH, true, .can_update = true, 397 .on_update = rtld_set_var_library_path), 398 LD_ENV_DESC(LIBRARY_PATH_FDS, true, .can_update = true, 399 .on_update = rtld_set_var_library_path_fds), 400 LD_ENV_DESC(LIBMAP_DISABLE, true, .can_update = true, 401 .on_update = rtld_set_var_libmap_disable), 402 LD_ENV_DESC(BIND_NOT, true, .can_update = true, 403 .on_update = rtld_set_var_bind_not), 404 LD_ENV_DESC(DEBUG, true, .can_update = true, 405 .on_update = rtld_set_var_debug), 406 LD_ENV_DESC(ELF_HINTS_PATH, true), 407 LD_ENV_DESC(LOADFLTR, true, .can_update = true, 408 .on_update = rtld_set_var_loadfltr), 409 LD_ENV_DESC(LIBRARY_PATH_RPATH, true, .can_update = true, 410 .on_update = rtld_set_var_library_path_rpath), 411 LD_ENV_DESC(PRELOAD_FDS, true), 412 LD_ENV_DESC(DYNAMIC_WEAK, true, .can_update = true, 413 .on_update = rtld_set_var_dynamic_weak), 414 LD_ENV_DESC(TRACE_LOADED_OBJECTS, false), 415 LD_ENV_DESC(UTRACE, false, .can_update = true), 416 LD_ENV_DESC(DUMP_REL_PRE, false, .can_update = true), 417 LD_ENV_DESC(DUMP_REL_POST, false, .can_update = true), 418 LD_ENV_DESC(TRACE_LOADED_OBJECTS_PROGNAME, false), 419 LD_ENV_DESC(TRACE_LOADED_OBJECTS_FMT1, false), 420 LD_ENV_DESC(TRACE_LOADED_OBJECTS_FMT2, false), 421 LD_ENV_DESC(TRACE_LOADED_OBJECTS_ALL, false), 422 LD_ENV_DESC(SHOW_AUXV, true), 423 LD_ENV_DESC(STATIC_TLS_EXTRA, false), 424 LD_ENV_DESC(NO_DL_ITERATE_PHDR_AFTER_FORK, false), 425 }; 426 427 const char * 428 ld_get_env_var(int idx) 429 { 430 return (ld_env_vars[idx].val); 431 } 432 433 static const char * 434 rtld_get_env_val(char **env, const char *name, size_t name_len) 435 { 436 char **m, *n, *v; 437 438 for (m = env; *m != NULL; m++) { 439 n = *m; 440 v = strchr(n, '='); 441 if (v == NULL) { 442 /* corrupt environment? */ 443 continue; 444 } 445 if (v - n == (ptrdiff_t)name_len && 446 strncmp(name, n, name_len) == 0) 447 return (v + 1); 448 } 449 return (NULL); 450 } 451 452 static void 453 rtld_init_env_vars_for_prefix(char **env, const char *env_prefix) 454 { 455 struct ld_env_var_desc *lvd; 456 size_t prefix_len, nlen; 457 char **m, *n, *v; 458 int i; 459 460 prefix_len = strlen(env_prefix); 461 for (m = env; *m != NULL; m++) { 462 n = *m; 463 if (strncmp(env_prefix, n, prefix_len) != 0) { 464 /* Not a rtld environment variable. */ 465 continue; 466 } 467 n += prefix_len; 468 v = strchr(n, '='); 469 if (v == NULL) { 470 /* corrupt environment? */ 471 continue; 472 } 473 for (i = 0; i < (int)nitems(ld_env_vars); i++) { 474 lvd = &ld_env_vars[i]; 475 if (lvd->val != NULL) { 476 /* Saw higher-priority variable name already. */ 477 continue; 478 } 479 nlen = strlen(lvd->n); 480 if (v - n == (ptrdiff_t)nlen && 481 strncmp(lvd->n, n, nlen) == 0) { 482 lvd->val = v + 1; 483 break; 484 } 485 } 486 } 487 } 488 489 static void 490 rtld_init_env_vars(char **env) 491 { 492 rtld_init_env_vars_for_prefix(env, ld_env_prefix); 493 } 494 495 static void 496 set_ld_elf_hints_path(void) 497 { 498 if (ld_elf_hints_path == NULL || strlen(ld_elf_hints_path) == 0) 499 ld_elf_hints_path = ld_elf_hints_default; 500 } 501 502 uintptr_t 503 rtld_round_page(uintptr_t x) 504 { 505 return (roundup2(x, page_size)); 506 } 507 508 uintptr_t 509 rtld_trunc_page(uintptr_t x) 510 { 511 return (rounddown2(x, page_size)); 512 } 513 514 /* 515 * Main entry point for dynamic linking. The first argument is the 516 * stack pointer. The stack is expected to be laid out as described 517 * in the SVR4 ABI specification, Intel 386 Processor Supplement. 518 * Specifically, the stack pointer points to a word containing 519 * ARGC. Following that in the stack is a null-terminated sequence 520 * of pointers to argument strings. Then comes a null-terminated 521 * sequence of pointers to environment strings. Finally, there is a 522 * sequence of "auxiliary vector" entries. 523 * 524 * The second argument points to a place to store the dynamic linker's 525 * exit procedure pointer and the third to a place to store the main 526 * program's object. 527 * 528 * The return value is the main program's entry point. 529 */ 530 func_ptr_type 531 _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp) 532 { 533 Elf_Auxinfo *aux, *auxp, *auxpf, *aux_info[AT_COUNT], auxtmp; 534 Objlist_Entry *entry; 535 Obj_Entry *last_interposer, *obj, *preload_tail; 536 const Elf_Phdr *phdr; 537 Objlist initlist; 538 RtldLockState lockstate; 539 struct stat st; 540 Elf_Addr *argcp; 541 char **argv, **env, **envp, *kexecpath; 542 const char *argv0, *binpath, *static_tls_extra; 543 struct ld_env_var_desc *lvd; 544 caddr_t imgentry; 545 char buf[MAXPATHLEN]; 546 int argc, fd, i, mib[4], old_osrel, osrel, phnum, rtld_argc; 547 size_t sz; 548 bool dir_enable, dir_ignore, direct_exec, explicit_fd, search_in_path; 549 550 /* 551 * On entry, the dynamic linker itself has not been relocated yet. 552 * Be very careful not to reference any global data until after 553 * init_rtld has returned. It is OK to reference file-scope statics 554 * and string constants, and to call static and global functions. 555 */ 556 557 /* Find the auxiliary vector on the stack. */ 558 argcp = sp; 559 argc = *sp++; 560 argv = (char **)sp; 561 sp += argc + 1; /* Skip over arguments and NULL terminator */ 562 env = (char **)sp; 563 while (*sp++ != 0) /* Skip over environment, and NULL terminator */ 564 ; 565 aux = (Elf_Auxinfo *)sp; 566 567 /* Digest the auxiliary vector. */ 568 for (i = 0; i < AT_COUNT; i++) 569 aux_info[i] = NULL; 570 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) { 571 if (auxp->a_type < AT_COUNT) 572 aux_info[auxp->a_type] = auxp; 573 } 574 arch_fix_auxv(aux, aux_info); 575 576 /* Initialize and relocate ourselves. */ 577 assert(aux_info[AT_BASE] != NULL); 578 init_rtld((caddr_t)aux_info[AT_BASE]->a_un.a_ptr, aux_info); 579 580 dlerror_dflt_init(); 581 582 __progname = obj_rtld.path; 583 argv0 = argv[0] != NULL ? argv[0] : "(null)"; 584 environ = env; 585 main_argc = argc; 586 main_argv = argv; 587 588 if (aux_info[AT_BSDFLAGS] != NULL && 589 (aux_info[AT_BSDFLAGS]->a_un.a_val & ELF_BSDF_SIGFASTBLK) != 0) 590 ld_fast_sigblock = true; 591 592 trust = !issetugid(); 593 direct_exec = false; 594 595 md_abi_variant_hook(aux_info); 596 rtld_init_env_vars(env); 597 598 fd = -1; 599 if (aux_info[AT_EXECFD] != NULL) { 600 fd = aux_info[AT_EXECFD]->a_un.a_val; 601 } else { 602 assert(aux_info[AT_PHDR] != NULL); 603 phdr = (const Elf_Phdr *)aux_info[AT_PHDR]->a_un.a_ptr; 604 if (phdr == obj_rtld.phdr) { 605 if (!trust) { 606 _rtld_error( 607 "Tainted process refusing to run binary %s", 608 argv0); 609 rtld_die(); 610 } 611 direct_exec = true; 612 613 dbg("opening main program in direct exec mode"); 614 if (argc >= 2) { 615 rtld_argc = parse_args(argv, argc, 616 &search_in_path, &fd, &argv0, &dir_ignore); 617 explicit_fd = (fd != -1); 618 binpath = NULL; 619 if (!explicit_fd) 620 fd = open_binary_fd(argv0, 621 search_in_path, &binpath); 622 if (fstat(fd, &st) == -1) { 623 _rtld_error( 624 "Failed to fstat FD %d (%s): %s", 625 fd, 626 explicit_fd ? 627 "user-provided descriptor" : 628 argv0, 629 rtld_strerror(errno)); 630 rtld_die(); 631 } 632 633 /* 634 * Rough emulation of the permission checks done 635 * by execve(2), only Unix DACs are checked, 636 * ACLs are ignored. Preserve the semantic of 637 * disabling owner to execute if owner x bit is 638 * cleared, even if others x bit is enabled. 639 * mmap(2) does not allow to mmap with PROT_EXEC 640 * if binary' file comes from noexec mount. We 641 * cannot set a text reference on the binary. 642 */ 643 dir_enable = false; 644 if (st.st_uid == geteuid()) { 645 if ((st.st_mode & S_IXUSR) != 0) 646 dir_enable = true; 647 } else if (st.st_gid == getegid()) { 648 if ((st.st_mode & S_IXGRP) != 0) 649 dir_enable = true; 650 } else if ((st.st_mode & S_IXOTH) != 0) { 651 dir_enable = true; 652 } 653 if (!dir_enable && !dir_ignore) { 654 _rtld_error( 655 "No execute permission for binary %s", 656 argv0); 657 rtld_die(); 658 } 659 660 /* 661 * For direct exec mode, argv[0] is the 662 * interpreter name, we must remove it and shift 663 * arguments left before invoking binary main. 664 * Since stack layout places environment 665 * pointers and aux vectors right after the 666 * terminating NULL, we must shift environment 667 * and aux as well. 668 */ 669 main_argc = argc - rtld_argc; 670 for (i = 0; i <= main_argc; i++) 671 argv[i] = argv[i + rtld_argc]; 672 *argcp -= rtld_argc; 673 environ = env = envp = argv + main_argc + 1; 674 dbg("move env from %p to %p", envp + rtld_argc, 675 envp); 676 do { 677 *envp = *(envp + rtld_argc); 678 } while (*envp++ != NULL); 679 aux = auxp = (Elf_Auxinfo *)envp; 680 auxpf = (Elf_Auxinfo *)(envp + rtld_argc); 681 dbg("move aux from %p to %p", auxpf, aux); 682 /* 683 * XXXKIB insert place for AT_EXECPATH if not 684 * present 685 */ 686 for (;; auxp++, auxpf++) { 687 /* 688 * NB: Use a temporary since *auxpf and 689 * *auxp overlap if rtld_argc is 1 690 */ 691 auxtmp = *auxpf; 692 *auxp = auxtmp; 693 if (auxp->a_type == AT_NULL) 694 break; 695 } 696 /* 697 * Since the auxiliary vector has moved, 698 * redigest it. 699 */ 700 for (i = 0; i < AT_COUNT; i++) 701 aux_info[i] = NULL; 702 for (auxp = aux; auxp->a_type != AT_NULL; 703 auxp++) { 704 if (auxp->a_type < AT_COUNT) 705 aux_info[auxp->a_type] = auxp; 706 } 707 708 /* 709 * Point AT_EXECPATH auxv and aux_info to the 710 * binary path. 711 */ 712 if (binpath == NULL) { 713 aux_info[AT_EXECPATH] = NULL; 714 } else { 715 if (aux_info[AT_EXECPATH] == NULL) { 716 aux_info[AT_EXECPATH] = xmalloc( 717 sizeof(Elf_Auxinfo)); 718 aux_info[AT_EXECPATH]->a_type = 719 AT_EXECPATH; 720 } 721 aux_info[AT_EXECPATH]->a_un.a_ptr = 722 __DECONST(void *, binpath); 723 } 724 } else { 725 _rtld_error("No binary"); 726 rtld_die(); 727 } 728 } 729 } 730 731 ld_bind_now = ld_get_env_var(LD_BIND_NOW); 732 733 /* 734 * If the process is tainted, then we un-set the dangerous environment 735 * variables. The process will be marked as tainted until setuid(2) 736 * is called. If any child process calls setuid(2) we do not want any 737 * future processes to honor the potentially un-safe variables. 738 */ 739 if (!trust) { 740 for (i = 0; i < (int)nitems(ld_env_vars); i++) { 741 lvd = &ld_env_vars[i]; 742 if (lvd->unsecure) 743 lvd->val = NULL; 744 } 745 } 746 747 rtld_recalc_debug(ld_get_env_var(LD_DEBUG)); 748 rtld_recalc_bind_not(ld_get_env_var(LD_BIND_NOT)); 749 ld_dynamic_weak = ld_get_env_var(LD_DYNAMIC_WEAK) == NULL; 750 libmap_disable = ld_get_env_var(LD_LIBMAP_DISABLE) != NULL; 751 libmap_override = ld_get_env_var(LD_LIBMAP); 752 ld_library_path = ld_get_env_var(LD_LIBRARY_PATH); 753 ld_library_dirs = ld_get_env_var(LD_LIBRARY_PATH_FDS); 754 ld_preload = ld_get_env_var(LD_PRELOAD); 755 ld_preload_fds = ld_get_env_var(LD_PRELOAD_FDS); 756 ld_elf_hints_path = ld_get_env_var(LD_ELF_HINTS_PATH); 757 ld_loadfltr = ld_get_env_var(LD_LOADFLTR) != NULL; 758 rtld_recalc_path_rpath(ld_get_env_var(LD_LIBRARY_PATH_RPATH)); 759 static_tls_extra = ld_get_env_var(LD_STATIC_TLS_EXTRA); 760 if (static_tls_extra != NULL && static_tls_extra[0] != '\0') { 761 sz = parse_integer(static_tls_extra); 762 if (sz >= RTLD_STATIC_TLS_EXTRA && sz <= SIZE_T_MAX) 763 ld_static_tls_extra = sz; 764 } 765 rtld_recalc_dangerous_ld_env(); 766 ld_tracing = ld_get_env_var(LD_TRACE_LOADED_OBJECTS); 767 ld_utrace = ld_get_env_var(LD_UTRACE); 768 769 set_ld_elf_hints_path(); 770 dbg("%s is initialized, base address = %p", __progname, 771 (caddr_t)aux_info[AT_BASE]->a_un.a_ptr); 772 dbg("RTLD dynamic = %p", obj_rtld.dynamic); 773 dbg("RTLD pltgot = %p", obj_rtld.pltgot); 774 775 dbg("initializing thread locks"); 776 lockdflt_init(); 777 778 /* 779 * Load the main program, or process its program header if it is 780 * already loaded. 781 */ 782 if (fd != -1) { /* Load the main program. */ 783 dbg("loading main program"); 784 obj_main = map_object(fd, argv0, NULL, true); 785 close(fd); 786 if (obj_main == NULL) 787 rtld_die(); 788 max_stack_flags = obj_main->stack_flags; 789 } else { /* Main program already loaded. */ 790 dbg("processing main program's program header"); 791 assert(aux_info[AT_PHDR] != NULL); 792 phdr = (const Elf_Phdr *)aux_info[AT_PHDR]->a_un.a_ptr; 793 assert(aux_info[AT_PHNUM] != NULL); 794 phnum = aux_info[AT_PHNUM]->a_un.a_val; 795 assert(aux_info[AT_PHENT] != NULL); 796 assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr)); 797 assert(aux_info[AT_ENTRY] != NULL); 798 imgentry = (caddr_t)aux_info[AT_ENTRY]->a_un.a_ptr; 799 if ((obj_main = digest_phdr(phdr, phnum, imgentry, argv0)) == 800 NULL) 801 rtld_die(); 802 } 803 804 if (aux_info[AT_EXECPATH] != NULL && fd == -1) { 805 kexecpath = aux_info[AT_EXECPATH]->a_un.a_ptr; 806 dbg("AT_EXECPATH %p %s", kexecpath, kexecpath); 807 if (kexecpath[0] == '/') 808 obj_main->path = kexecpath; 809 else if (getcwd(buf, sizeof(buf)) == NULL || 810 strlcat(buf, "/", sizeof(buf)) >= sizeof(buf) || 811 strlcat(buf, kexecpath, sizeof(buf)) >= sizeof(buf)) 812 obj_main->path = xstrdup(argv0); 813 else 814 obj_main->path = xstrdup(buf); 815 } else { 816 dbg("No AT_EXECPATH or direct exec"); 817 obj_main->path = xstrdup(argv0); 818 } 819 dbg("obj_main path %s", obj_main->path); 820 obj_main->mainprog = true; 821 822 if (aux_info[AT_STACKPROT] != NULL && 823 aux_info[AT_STACKPROT]->a_un.a_val != 0) 824 stack_prot = aux_info[AT_STACKPROT]->a_un.a_val; 825 826 #ifndef COMPAT_libcompat 827 /* 828 * Get the actual dynamic linker pathname from the executable if 829 * possible. (It should always be possible.) That ensures that 830 * gdb will find the right dynamic linker even if a non-standard 831 * one is being used. 832 */ 833 if (obj_main->interp != NULL && 834 strcmp(obj_main->interp, obj_rtld.path) != 0) { 835 free(obj_rtld.path); 836 obj_rtld.path = xstrdup(obj_main->interp); 837 __progname = obj_rtld.path; 838 } 839 #endif 840 841 if (!digest_dynamic(obj_main, 0)) 842 rtld_die(); 843 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", 844 obj_main->path, obj_main->valid_hash_sysv, obj_main->valid_hash_gnu, 845 obj_main->dynsymcount); 846 847 linkmap_add(obj_main); 848 linkmap_add(&obj_rtld); 849 LD_UTRACE(UTRACE_LOAD_OBJECT, obj_main, obj_main->mapbase, 850 obj_main->mapsize, 0, obj_main->path); 851 LD_UTRACE(UTRACE_LOAD_OBJECT, &obj_rtld, obj_rtld.mapbase, 852 obj_rtld.mapsize, 0, obj_rtld.path); 853 854 /* Link the main program into the list of objects. */ 855 TAILQ_INSERT_HEAD(&obj_list, obj_main, next); 856 obj_count++; 857 obj_loads++; 858 859 /* Initialize a fake symbol for resolving undefined weak references. */ 860 sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE); 861 sym_zero.st_shndx = SHN_UNDEF; 862 sym_zero.st_value = -(uintptr_t)obj_main->relocbase; 863 864 if (!libmap_disable) 865 libmap_disable = (bool)lm_init(libmap_override); 866 867 if (aux_info[AT_KPRELOAD] != NULL && 868 aux_info[AT_KPRELOAD]->a_un.a_ptr != NULL) { 869 dbg("loading kernel vdso"); 870 if (load_kpreload(aux_info[AT_KPRELOAD]->a_un.a_ptr) == -1) 871 rtld_die(); 872 } 873 874 dbg("loading LD_PRELOAD_FDS libraries"); 875 if (load_preload_objects(ld_preload_fds, true) == -1) 876 rtld_die(); 877 878 dbg("loading LD_PRELOAD libraries"); 879 if (load_preload_objects(ld_preload, false) == -1) 880 rtld_die(); 881 preload_tail = globallist_curr(TAILQ_LAST(&obj_list, obj_entry_q)); 882 883 dbg("loading needed objects"); 884 if (load_needed_objects(obj_main, 885 ld_tracing != NULL ? RTLD_LO_TRACE : 0) == -1) 886 rtld_die(); 887 888 /* Make a list of all objects loaded at startup. */ 889 last_interposer = obj_main; 890 TAILQ_FOREACH(obj, &obj_list, next) { 891 if (obj->marker) 892 continue; 893 if (obj->z_interpose && obj != obj_main) { 894 objlist_put_after(&list_main, last_interposer, obj); 895 last_interposer = obj; 896 } else { 897 objlist_push_tail(&list_main, obj); 898 } 899 obj->refcount++; 900 } 901 902 dbg("checking for required versions"); 903 if (rtld_verify_versions(&list_main) == -1 && !ld_tracing) 904 rtld_die(); 905 906 if (ld_get_env_var(LD_SHOW_AUXV) != NULL) 907 dump_auxv(aux_info); 908 909 if (ld_tracing) { /* We're done */ 910 trace_loaded_objects(obj_main, true); 911 exit(0); 912 } 913 914 if (ld_get_env_var(LD_DUMP_REL_PRE) != NULL) { 915 dump_relocations(obj_main); 916 exit(0); 917 } 918 919 /* 920 * Processing tls relocations requires having the tls offsets 921 * initialized. Prepare offsets before starting initial 922 * relocation processing. 923 */ 924 dbg("initializing initial thread local storage offsets"); 925 STAILQ_FOREACH(entry, &list_main, link) { 926 /* 927 * Allocate all the initial objects out of the static TLS 928 * block even if they didn't ask for it. 929 */ 930 allocate_tls_offset(entry->obj); 931 } 932 933 if (!allocate_tls_offset_common(&tcb_list_entry_offset, 934 sizeof(struct tcb_list_entry), _Alignof(struct tcb_list_entry), 935 0)) { 936 /* 937 * This should be impossible as the static block size is not 938 * yet fixed, but catch and diagnose it failing if that ever 939 * changes or somehow turns out to be false. 940 */ 941 _rtld_error("Could not allocate offset for tcb_list_entry"); 942 rtld_die(); 943 } 944 dbg("tcb_list_entry_offset %zu", tcb_list_entry_offset); 945 946 if (relocate_objects(obj_main, 947 ld_bind_now != NULL && *ld_bind_now != '\0', &obj_rtld, 948 SYMLOOK_EARLY, NULL) == -1) 949 rtld_die(); 950 951 dbg("doing copy relocations"); 952 if (do_copy_relocations(obj_main) == -1) 953 rtld_die(); 954 955 if (ld_get_env_var(LD_DUMP_REL_POST) != NULL) { 956 dump_relocations(obj_main); 957 exit(0); 958 } 959 960 ifunc_init(aux_info); 961 962 /* 963 * Setup TLS for main thread. This must be done after the 964 * relocations are processed, since tls initialization section 965 * might be the subject for relocations. 966 */ 967 dbg("initializing initial thread local storage"); 968 allocate_initial_tls(globallist_curr(TAILQ_FIRST(&obj_list))); 969 970 dbg("initializing key program variables"); 971 set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : ""); 972 set_program_var("environ", env); 973 set_program_var("__elf_aux_vector", aux); 974 975 /* Make a list of init functions to call. */ 976 objlist_init(&initlist); 977 initlist_for_loaded_obj(globallist_curr(TAILQ_FIRST(&obj_list)), 978 preload_tail, &initlist); 979 980 r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */ 981 982 map_stacks_exec(NULL); 983 984 if (!obj_main->crt_no_init) { 985 /* 986 * Make sure we don't call the main program's init and fini 987 * functions for binaries linked with old crt1 which calls 988 * _init itself. 989 */ 990 obj_main->init = obj_main->fini = 0; 991 obj_main->preinit_array = obj_main->init_array = 992 obj_main->fini_array = NULL; 993 } 994 995 if (direct_exec) { 996 /* Set osrel for direct-execed binary */ 997 mib[0] = CTL_KERN; 998 mib[1] = KERN_PROC; 999 mib[2] = KERN_PROC_OSREL; 1000 mib[3] = getpid(); 1001 osrel = obj_main->osrel; 1002 sz = sizeof(old_osrel); 1003 dbg("setting osrel to %d", osrel); 1004 (void)sysctl(mib, 4, &old_osrel, &sz, &osrel, sizeof(osrel)); 1005 } 1006 1007 wlock_acquire(rtld_bind_lock, &lockstate); 1008 1009 dbg("resolving ifuncs"); 1010 if (initlist_objects_ifunc(&initlist, 1011 ld_bind_now != NULL && *ld_bind_now != '\0', SYMLOOK_EARLY, 1012 &lockstate) == -1) 1013 rtld_die(); 1014 1015 rtld_exit_ptr = rtld_exit; 1016 if (obj_main->crt_no_init) 1017 preinit_main(); 1018 objlist_call_init(&initlist, &lockstate); 1019 _r_debug_postinit(&obj_main->linkmap); 1020 objlist_clear(&initlist); 1021 dbg("loading filtees"); 1022 TAILQ_FOREACH(obj, &obj_list, next) { 1023 if (obj->marker) 1024 continue; 1025 if (ld_loadfltr || obj->z_loadfltr) 1026 load_filtees(obj, 0, &lockstate); 1027 } 1028 1029 dbg("enforcing main obj relro"); 1030 if (obj_enforce_relro(obj_main) == -1) 1031 rtld_die(); 1032 1033 lock_release(rtld_bind_lock, &lockstate); 1034 1035 dbg("transferring control to program entry point = %p", 1036 obj_main->entry); 1037 1038 /* Return the exit procedure and the program entry point. */ 1039 *exit_proc = rtld_exit_ptr; 1040 *objp = obj_main; 1041 return ((func_ptr_type)obj_main->entry); 1042 } 1043 1044 void * 1045 rtld_resolve_ifunc(const Obj_Entry *obj, const Elf_Sym *def) 1046 { 1047 void *ptr; 1048 Elf_Addr target; 1049 1050 ptr = (void *)make_function_pointer(def, obj); 1051 target = call_ifunc_resolver(ptr); 1052 return ((void *)target); 1053 } 1054 1055 Elf_Addr 1056 _rtld_bind(Obj_Entry *obj, Elf_Size reloff) 1057 { 1058 const Elf_Rel *rel; 1059 const Elf_Sym *def; 1060 const Obj_Entry *defobj; 1061 Elf_Addr *where; 1062 Elf_Addr target; 1063 RtldLockState lockstate; 1064 1065 relock: 1066 rlock_acquire(rtld_bind_lock, &lockstate); 1067 if (sigsetjmp(lockstate.env, 0) != 0) 1068 lock_upgrade(rtld_bind_lock, &lockstate); 1069 if (obj->pltrel) 1070 rel = (const Elf_Rel *)((const char *)obj->pltrel + reloff); 1071 else 1072 rel = (const Elf_Rel *)((const char *)obj->pltrela + reloff); 1073 1074 where = (Elf_Addr *)(obj->relocbase + rel->r_offset); 1075 def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, SYMLOOK_IN_PLT, 1076 NULL, &lockstate); 1077 if (def == NULL) 1078 rtld_die(); 1079 if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) { 1080 if (lockstate_wlocked(&lockstate)) { 1081 lock_release(rtld_bind_lock, &lockstate); 1082 goto relock; 1083 } 1084 target = (Elf_Addr)rtld_resolve_ifunc(defobj, def); 1085 } else { 1086 target = (Elf_Addr)(defobj->relocbase + def->st_value); 1087 } 1088 1089 dbg("\"%s\" in \"%s\" ==> %p in \"%s\"", defobj->strtab + def->st_name, 1090 obj->path == NULL ? NULL : basename(obj->path), (void *)target, 1091 defobj->path == NULL ? NULL : basename(defobj->path)); 1092 1093 /* 1094 * Write the new contents for the jmpslot. Note that depending on 1095 * architecture, the value which we need to return back to the 1096 * lazy binding trampoline may or may not be the target 1097 * address. The value returned from reloc_jmpslot() is the value 1098 * that the trampoline needs. 1099 */ 1100 target = reloc_jmpslot(where, target, defobj, obj, rel); 1101 lock_release(rtld_bind_lock, &lockstate); 1102 return (target); 1103 } 1104 1105 /* 1106 * Error reporting function. Use it like printf. If formats the message 1107 * into a buffer, and sets things up so that the next call to dlerror() 1108 * will return the message. 1109 */ 1110 void 1111 _rtld_error(const char *fmt, ...) 1112 { 1113 va_list ap; 1114 1115 va_start(ap, fmt); 1116 rtld_vsnprintf(lockinfo.dlerror_loc(), lockinfo.dlerror_loc_sz, fmt, 1117 ap); 1118 va_end(ap); 1119 *lockinfo.dlerror_seen() = 0; 1120 dbg("rtld_error: %s", lockinfo.dlerror_loc()); 1121 LD_UTRACE(UTRACE_RTLD_ERROR, NULL, NULL, 0, 0, lockinfo.dlerror_loc()); 1122 } 1123 1124 /* 1125 * Return a dynamically-allocated copy of the current error message, if any. 1126 */ 1127 static struct dlerror_save * 1128 errmsg_save(void) 1129 { 1130 struct dlerror_save *res; 1131 1132 res = xmalloc(sizeof(*res)); 1133 res->seen = *lockinfo.dlerror_seen(); 1134 if (res->seen == 0) 1135 res->msg = xstrdup(lockinfo.dlerror_loc()); 1136 return (res); 1137 } 1138 1139 /* 1140 * Restore the current error message from a copy which was previously saved 1141 * by errmsg_save(). The copy is freed. 1142 */ 1143 static void 1144 errmsg_restore(struct dlerror_save *saved_msg) 1145 { 1146 if (saved_msg == NULL || saved_msg->seen == 1) { 1147 *lockinfo.dlerror_seen() = 1; 1148 } else { 1149 *lockinfo.dlerror_seen() = 0; 1150 strlcpy(lockinfo.dlerror_loc(), saved_msg->msg, 1151 lockinfo.dlerror_loc_sz); 1152 free(saved_msg->msg); 1153 } 1154 free(saved_msg); 1155 } 1156 1157 static const char * 1158 basename(const char *name) 1159 { 1160 const char *p; 1161 1162 p = strrchr(name, '/'); 1163 return (p != NULL ? p + 1 : name); 1164 } 1165 1166 static struct utsname uts; 1167 1168 static char * 1169 origin_subst_one(Obj_Entry *obj, char *real, const char *kw, const char *subst, 1170 bool may_free) 1171 { 1172 char *p, *p1, *res, *resp; 1173 int subst_len, kw_len, subst_count, old_len, new_len; 1174 1175 kw_len = strlen(kw); 1176 1177 /* 1178 * First, count the number of the keyword occurrences, to 1179 * preallocate the final string. 1180 */ 1181 for (p = real, subst_count = 0;; p = p1 + kw_len, subst_count++) { 1182 p1 = strstr(p, kw); 1183 if (p1 == NULL) 1184 break; 1185 } 1186 1187 /* 1188 * If the keyword is not found, just return. 1189 * 1190 * Return non-substituted string if resolution failed. We 1191 * cannot do anything more reasonable, the failure mode of the 1192 * caller is unresolved library anyway. 1193 */ 1194 if (subst_count == 0 || (obj != NULL && !obj_resolve_origin(obj))) 1195 return (may_free ? real : xstrdup(real)); 1196 if (obj != NULL) 1197 subst = obj->origin_path; 1198 1199 /* 1200 * There is indeed something to substitute. Calculate the 1201 * length of the resulting string, and allocate it. 1202 */ 1203 subst_len = strlen(subst); 1204 old_len = strlen(real); 1205 new_len = old_len + (subst_len - kw_len) * subst_count; 1206 res = xmalloc(new_len + 1); 1207 1208 /* 1209 * Now, execute the substitution loop. 1210 */ 1211 for (p = real, resp = res, *resp = '\0';;) { 1212 p1 = strstr(p, kw); 1213 if (p1 != NULL) { 1214 /* Copy the prefix before keyword. */ 1215 memcpy(resp, p, p1 - p); 1216 resp += p1 - p; 1217 /* Keyword replacement. */ 1218 memcpy(resp, subst, subst_len); 1219 resp += subst_len; 1220 *resp = '\0'; 1221 p = p1 + kw_len; 1222 } else 1223 break; 1224 } 1225 1226 /* Copy to the end of string and finish. */ 1227 strcat(resp, p); 1228 if (may_free) 1229 free(real); 1230 return (res); 1231 } 1232 1233 static const struct { 1234 const char *kw; 1235 bool pass_obj; 1236 const char *subst; 1237 } tokens[] = { 1238 { .kw = "$ORIGIN", .pass_obj = true, .subst = NULL }, 1239 { .kw = "${ORIGIN}", .pass_obj = true, .subst = NULL }, 1240 { .kw = "$OSNAME", .pass_obj = false, .subst = uts.sysname }, 1241 { .kw = "${OSNAME}", .pass_obj = false, .subst = uts.sysname }, 1242 { .kw = "$OSREL", .pass_obj = false, .subst = uts.release }, 1243 { .kw = "${OSREL}", .pass_obj = false, .subst = uts.release }, 1244 { .kw = "$PLATFORM", .pass_obj = false, .subst = uts.machine }, 1245 { .kw = "${PLATFORM}", .pass_obj = false, .subst = uts.machine }, 1246 { .kw = "$LIB", .pass_obj = false, .subst = TOKEN_LIB }, 1247 { .kw = "${LIB}", .pass_obj = false, .subst = TOKEN_LIB }, 1248 }; 1249 1250 static char * 1251 origin_subst(Obj_Entry *obj, const char *real) 1252 { 1253 char *res; 1254 int i; 1255 1256 if (obj == NULL || !trust) 1257 return (xstrdup(real)); 1258 if (uts.sysname[0] == '\0') { 1259 if (uname(&uts) != 0) { 1260 _rtld_error("utsname failed: %d", errno); 1261 return (NULL); 1262 } 1263 } 1264 1265 /* __DECONST is safe here since without may_free real is unchanged */ 1266 res = __DECONST(char *, real); 1267 for (i = 0; i < (int)nitems(tokens); i++) { 1268 res = origin_subst_one(tokens[i].pass_obj ? obj : NULL, res, 1269 tokens[i].kw, tokens[i].subst, i != 0); 1270 } 1271 return (res); 1272 } 1273 1274 void 1275 rtld_die(void) 1276 { 1277 const char *msg = dlerror(); 1278 1279 if (msg == NULL) 1280 msg = "Fatal error"; 1281 rtld_fdputstr(STDERR_FILENO, _BASENAME_RTLD ": "); 1282 rtld_fdputstr(STDERR_FILENO, msg); 1283 rtld_fdputchar(STDERR_FILENO, '\n'); 1284 _exit(1); 1285 } 1286 1287 /* 1288 * Process a shared object's DYNAMIC section, and save the important 1289 * information in its Obj_Entry structure. 1290 */ 1291 static void 1292 digest_dynamic1(Obj_Entry *obj, int early, const Elf_Dyn **dyn_rpath, 1293 const Elf_Dyn **dyn_soname, const Elf_Dyn **dyn_runpath) 1294 { 1295 const Elf_Dyn *dynp; 1296 Needed_Entry **needed_tail = &obj->needed; 1297 Needed_Entry **needed_filtees_tail = &obj->needed_filtees; 1298 Needed_Entry **needed_aux_filtees_tail = &obj->needed_aux_filtees; 1299 const Elf_Hashelt *hashtab; 1300 const Elf32_Word *hashval; 1301 Elf32_Word bkt, nmaskwords; 1302 int bloom_size32; 1303 int plttype = DT_REL; 1304 1305 *dyn_rpath = NULL; 1306 *dyn_soname = NULL; 1307 *dyn_runpath = NULL; 1308 1309 obj->bind_now = false; 1310 dynp = obj->dynamic; 1311 if (dynp == NULL) 1312 return; 1313 for (; dynp->d_tag != DT_NULL; dynp++) { 1314 switch (dynp->d_tag) { 1315 case DT_REL: 1316 obj->rel = (const Elf_Rel *)(obj->relocbase + 1317 dynp->d_un.d_ptr); 1318 break; 1319 1320 case DT_RELSZ: 1321 obj->relsize = dynp->d_un.d_val; 1322 break; 1323 1324 case DT_RELENT: 1325 assert(dynp->d_un.d_val == sizeof(Elf_Rel)); 1326 break; 1327 1328 case DT_JMPREL: 1329 obj->pltrel = (const Elf_Rel *)(obj->relocbase + 1330 dynp->d_un.d_ptr); 1331 break; 1332 1333 case DT_PLTRELSZ: 1334 obj->pltrelsize = dynp->d_un.d_val; 1335 break; 1336 1337 case DT_RELA: 1338 obj->rela = (const Elf_Rela *)(obj->relocbase + 1339 dynp->d_un.d_ptr); 1340 break; 1341 1342 case DT_RELASZ: 1343 obj->relasize = dynp->d_un.d_val; 1344 break; 1345 1346 case DT_RELAENT: 1347 assert(dynp->d_un.d_val == sizeof(Elf_Rela)); 1348 break; 1349 1350 case DT_RELR: 1351 obj->relr = (const Elf_Relr *)(obj->relocbase + 1352 dynp->d_un.d_ptr); 1353 break; 1354 1355 case DT_RELRSZ: 1356 obj->relrsize = dynp->d_un.d_val; 1357 break; 1358 1359 case DT_RELRENT: 1360 assert(dynp->d_un.d_val == sizeof(Elf_Relr)); 1361 break; 1362 1363 case DT_PLTREL: 1364 plttype = dynp->d_un.d_val; 1365 assert( 1366 dynp->d_un.d_val == DT_REL || plttype == DT_RELA); 1367 break; 1368 1369 case DT_SYMTAB: 1370 obj->symtab = (const Elf_Sym *)(obj->relocbase + 1371 dynp->d_un.d_ptr); 1372 break; 1373 1374 case DT_SYMENT: 1375 assert(dynp->d_un.d_val == sizeof(Elf_Sym)); 1376 break; 1377 1378 case DT_STRTAB: 1379 obj->strtab = (const char *)(obj->relocbase + 1380 dynp->d_un.d_ptr); 1381 break; 1382 1383 case DT_STRSZ: 1384 obj->strsize = dynp->d_un.d_val; 1385 break; 1386 1387 case DT_VERNEED: 1388 obj->verneed = (const Elf_Verneed *)(obj->relocbase + 1389 dynp->d_un.d_val); 1390 break; 1391 1392 case DT_VERNEEDNUM: 1393 obj->verneednum = dynp->d_un.d_val; 1394 break; 1395 1396 case DT_VERDEF: 1397 obj->verdef = (const Elf_Verdef *)(obj->relocbase + 1398 dynp->d_un.d_val); 1399 break; 1400 1401 case DT_VERDEFNUM: 1402 obj->verdefnum = dynp->d_un.d_val; 1403 break; 1404 1405 case DT_VERSYM: 1406 obj->versyms = (const Elf_Versym *)(obj->relocbase + 1407 dynp->d_un.d_val); 1408 break; 1409 1410 case DT_HASH: { 1411 hashtab = (const Elf_Hashelt *)(obj->relocbase + 1412 dynp->d_un.d_ptr); 1413 obj->nbuckets = hashtab[0]; 1414 obj->nchains = hashtab[1]; 1415 obj->buckets = hashtab + 2; 1416 obj->chains = obj->buckets + obj->nbuckets; 1417 obj->valid_hash_sysv = obj->nbuckets > 0 && 1418 obj->nchains > 0 && obj->buckets != NULL; 1419 } break; 1420 1421 case DT_GNU_HASH: { 1422 hashtab = (const Elf_Hashelt *)(obj->relocbase + 1423 dynp->d_un.d_ptr); 1424 obj->nbuckets_gnu = hashtab[0]; 1425 obj->symndx_gnu = hashtab[1]; 1426 nmaskwords = hashtab[2]; 1427 bloom_size32 = (__ELF_WORD_SIZE / 32) * nmaskwords; 1428 obj->maskwords_bm_gnu = nmaskwords - 1; 1429 obj->shift2_gnu = hashtab[3]; 1430 obj->bloom_gnu = (const Elf_Addr *)(hashtab + 4); 1431 obj->buckets_gnu = hashtab + 4 + bloom_size32; 1432 obj->chain_zero_gnu = obj->buckets_gnu + 1433 obj->nbuckets_gnu - obj->symndx_gnu; 1434 /* Number of bitmask words is required to be power of 2 1435 */ 1436 obj->valid_hash_gnu = powerof2(nmaskwords) && 1437 obj->nbuckets_gnu > 0 && obj->buckets_gnu != NULL; 1438 } break; 1439 1440 case DT_NEEDED: 1441 if (!obj->rtld) { 1442 Needed_Entry *nep = NEW(Needed_Entry); 1443 nep->name = dynp->d_un.d_val; 1444 nep->obj = NULL; 1445 nep->next = NULL; 1446 1447 *needed_tail = nep; 1448 needed_tail = &nep->next; 1449 } 1450 break; 1451 1452 case DT_FILTER: 1453 if (!obj->rtld) { 1454 Needed_Entry *nep = NEW(Needed_Entry); 1455 nep->name = dynp->d_un.d_val; 1456 nep->obj = NULL; 1457 nep->next = NULL; 1458 1459 *needed_filtees_tail = nep; 1460 needed_filtees_tail = &nep->next; 1461 1462 if (obj->linkmap.l_refname == NULL) 1463 obj->linkmap.l_refname = 1464 (char *)dynp->d_un.d_val; 1465 } 1466 break; 1467 1468 case DT_AUXILIARY: 1469 if (!obj->rtld) { 1470 Needed_Entry *nep = NEW(Needed_Entry); 1471 nep->name = dynp->d_un.d_val; 1472 nep->obj = NULL; 1473 nep->next = NULL; 1474 1475 *needed_aux_filtees_tail = nep; 1476 needed_aux_filtees_tail = &nep->next; 1477 } 1478 break; 1479 1480 case DT_PLTGOT: 1481 obj->pltgot = (Elf_Addr *)(obj->relocbase + 1482 dynp->d_un.d_ptr); 1483 break; 1484 1485 case DT_TEXTREL: 1486 obj->textrel = true; 1487 break; 1488 1489 case DT_SYMBOLIC: 1490 obj->symbolic = true; 1491 break; 1492 1493 case DT_RPATH: 1494 /* 1495 * We have to wait until later to process this, because 1496 * we might not have gotten the address of the string 1497 * table yet. 1498 */ 1499 *dyn_rpath = dynp; 1500 break; 1501 1502 case DT_SONAME: 1503 *dyn_soname = dynp; 1504 break; 1505 1506 case DT_RUNPATH: 1507 *dyn_runpath = dynp; 1508 break; 1509 1510 case DT_INIT: 1511 obj->init = (uintptr_t)(obj->relocbase + 1512 dynp->d_un.d_ptr); 1513 break; 1514 1515 case DT_PREINIT_ARRAY: 1516 obj->preinit_array = (uintptr_t *)(obj->relocbase + 1517 dynp->d_un.d_ptr); 1518 break; 1519 1520 case DT_PREINIT_ARRAYSZ: 1521 obj->preinit_array_num = dynp->d_un.d_val / 1522 sizeof(uintptr_t); 1523 break; 1524 1525 case DT_INIT_ARRAY: 1526 obj->init_array = (uintptr_t *)(obj->relocbase + 1527 dynp->d_un.d_ptr); 1528 break; 1529 1530 case DT_INIT_ARRAYSZ: 1531 obj->init_array_num = dynp->d_un.d_val / 1532 sizeof(uintptr_t); 1533 break; 1534 1535 case DT_FINI: 1536 obj->fini = (uintptr_t)(obj->relocbase + 1537 dynp->d_un.d_ptr); 1538 break; 1539 1540 case DT_FINI_ARRAY: 1541 obj->fini_array = (uintptr_t *)(obj->relocbase + 1542 dynp->d_un.d_ptr); 1543 break; 1544 1545 case DT_FINI_ARRAYSZ: 1546 obj->fini_array_num = dynp->d_un.d_val / 1547 sizeof(uintptr_t); 1548 break; 1549 1550 case DT_DEBUG: 1551 if (!early) 1552 dbg("Filling in DT_DEBUG entry"); 1553 (__DECONST(Elf_Dyn *, dynp))->d_un.d_ptr = 1554 (Elf_Addr)&r_debug; 1555 break; 1556 1557 case DT_FLAGS: 1558 if (dynp->d_un.d_val & DF_ORIGIN) 1559 obj->z_origin = true; 1560 if (dynp->d_un.d_val & DF_SYMBOLIC) 1561 obj->symbolic = true; 1562 if (dynp->d_un.d_val & DF_TEXTREL) 1563 obj->textrel = true; 1564 if (dynp->d_un.d_val & DF_BIND_NOW) 1565 obj->bind_now = true; 1566 if (dynp->d_un.d_val & DF_STATIC_TLS) 1567 obj->static_tls = true; 1568 break; 1569 1570 case DT_FLAGS_1: 1571 if (dynp->d_un.d_val & DF_1_NOOPEN) 1572 obj->z_noopen = true; 1573 if (dynp->d_un.d_val & DF_1_ORIGIN) 1574 obj->z_origin = true; 1575 if (dynp->d_un.d_val & DF_1_GLOBAL) 1576 obj->z_global = true; 1577 if (dynp->d_un.d_val & DF_1_BIND_NOW) 1578 obj->bind_now = true; 1579 if (dynp->d_un.d_val & DF_1_NODELETE) 1580 obj->z_nodelete = true; 1581 if (dynp->d_un.d_val & DF_1_LOADFLTR) 1582 obj->z_loadfltr = true; 1583 if (dynp->d_un.d_val & DF_1_INTERPOSE) 1584 obj->z_interpose = true; 1585 if (dynp->d_un.d_val & DF_1_NODEFLIB) 1586 obj->z_nodeflib = true; 1587 if (dynp->d_un.d_val & DF_1_PIE) 1588 obj->z_pie = true; 1589 if (dynp->d_un.d_val & DF_1_INITFIRST) 1590 obj->z_initfirst = true; 1591 break; 1592 1593 default: 1594 if (arch_digest_dynamic(obj, dynp)) 1595 break; 1596 1597 if (!early) { 1598 dbg("Ignoring d_tag %ld = %#lx", 1599 (long)dynp->d_tag, (long)dynp->d_tag); 1600 } 1601 break; 1602 } 1603 } 1604 1605 obj->traced = false; 1606 1607 if (plttype == DT_RELA) { 1608 obj->pltrela = (const Elf_Rela *)obj->pltrel; 1609 obj->pltrel = NULL; 1610 obj->pltrelasize = obj->pltrelsize; 1611 obj->pltrelsize = 0; 1612 } 1613 1614 /* Determine size of dynsym table (equal to nchains of sysv hash) */ 1615 if (obj->valid_hash_sysv) 1616 obj->dynsymcount = obj->nchains; 1617 else if (obj->valid_hash_gnu) { 1618 obj->dynsymcount = 0; 1619 for (bkt = 0; bkt < obj->nbuckets_gnu; bkt++) { 1620 if (obj->buckets_gnu[bkt] == 0) 1621 continue; 1622 hashval = &obj->chain_zero_gnu[obj->buckets_gnu[bkt]]; 1623 do 1624 obj->dynsymcount++; 1625 while ((*hashval++ & 1u) == 0); 1626 } 1627 obj->dynsymcount += obj->symndx_gnu; 1628 } 1629 1630 if (obj->linkmap.l_refname != NULL) 1631 obj->linkmap.l_refname = obj->strtab + 1632 (unsigned long)obj->linkmap.l_refname; 1633 } 1634 1635 static bool 1636 obj_resolve_origin(Obj_Entry *obj) 1637 { 1638 if (obj->origin_path != NULL) 1639 return (true); 1640 obj->origin_path = xmalloc(PATH_MAX); 1641 return (rtld_dirname_abs(obj->path, obj->origin_path) != -1); 1642 } 1643 1644 static bool 1645 digest_dynamic2(Obj_Entry *obj, const Elf_Dyn *dyn_rpath, 1646 const Elf_Dyn *dyn_soname, const Elf_Dyn *dyn_runpath) 1647 { 1648 if (obj->z_origin && !obj_resolve_origin(obj)) 1649 return (false); 1650 1651 if (dyn_runpath != NULL) { 1652 obj->runpath = (const char *)obj->strtab + 1653 dyn_runpath->d_un.d_val; 1654 obj->runpath = origin_subst(obj, obj->runpath); 1655 } else if (dyn_rpath != NULL) { 1656 obj->rpath = (const char *)obj->strtab + dyn_rpath->d_un.d_val; 1657 obj->rpath = origin_subst(obj, obj->rpath); 1658 } 1659 if (dyn_soname != NULL) 1660 object_add_name(obj, obj->strtab + dyn_soname->d_un.d_val); 1661 return (true); 1662 } 1663 1664 static bool 1665 digest_dynamic(Obj_Entry *obj, int early) 1666 { 1667 const Elf_Dyn *dyn_rpath; 1668 const Elf_Dyn *dyn_soname; 1669 const Elf_Dyn *dyn_runpath; 1670 1671 digest_dynamic1(obj, early, &dyn_rpath, &dyn_soname, &dyn_runpath); 1672 return (digest_dynamic2(obj, dyn_rpath, dyn_soname, dyn_runpath)); 1673 } 1674 1675 /* 1676 * Process a shared object's program header. This is used only for the 1677 * main program, when the kernel has already loaded the main program 1678 * into memory before calling the dynamic linker. It creates and 1679 * returns an Obj_Entry structure. 1680 */ 1681 static Obj_Entry * 1682 digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path) 1683 { 1684 Obj_Entry *obj; 1685 const Elf_Phdr *phlimit = phdr + phnum; 1686 const Elf_Phdr *ph; 1687 Elf_Addr note_start, note_end; 1688 int nsegs = 0; 1689 1690 obj = obj_new(); 1691 for (ph = phdr; ph < phlimit; ph++) { 1692 if (ph->p_type != PT_PHDR) 1693 continue; 1694 1695 obj->phdr = phdr; 1696 obj->phnum = ph->p_memsz / sizeof(*ph); 1697 obj->relocbase = __DECONST(char *, phdr) - ph->p_vaddr; 1698 break; 1699 } 1700 1701 obj->stack_flags = PF_X | PF_R | PF_W; 1702 1703 for (ph = phdr; ph < phlimit; ph++) { 1704 switch (ph->p_type) { 1705 case PT_INTERP: 1706 obj->interp = (const char *)(ph->p_vaddr + 1707 obj->relocbase); 1708 break; 1709 1710 case PT_LOAD: 1711 if (nsegs == 0) { /* First load segment */ 1712 obj->vaddrbase = rtld_trunc_page(ph->p_vaddr); 1713 obj->mapbase = obj->vaddrbase + obj->relocbase; 1714 } else { /* Last load segment */ 1715 obj->mapsize = rtld_round_page( 1716 ph->p_vaddr + ph->p_memsz) - 1717 obj->vaddrbase; 1718 } 1719 nsegs++; 1720 break; 1721 1722 case PT_DYNAMIC: 1723 obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + 1724 obj->relocbase); 1725 break; 1726 1727 case PT_TLS: 1728 obj->tlsindex = 1; 1729 obj->tlssize = ph->p_memsz; 1730 obj->tlsalign = ph->p_align; 1731 obj->tlsinitsize = ph->p_filesz; 1732 obj->tlsinit = (void *)(ph->p_vaddr + obj->relocbase); 1733 obj->tlspoffset = ph->p_offset; 1734 break; 1735 1736 case PT_GNU_STACK: 1737 obj->stack_flags = ph->p_flags; 1738 break; 1739 1740 case PT_NOTE: 1741 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; 1742 note_end = note_start + ph->p_filesz; 1743 digest_notes(obj, note_start, note_end); 1744 break; 1745 } 1746 } 1747 if (nsegs < 1) { 1748 _rtld_error("%s: too few PT_LOAD segments", path); 1749 return (NULL); 1750 } 1751 1752 obj->entry = entry; 1753 return (obj); 1754 } 1755 1756 void 1757 digest_notes(Obj_Entry *obj, Elf_Addr note_start, Elf_Addr note_end) 1758 { 1759 const Elf_Note *note; 1760 const char *note_name; 1761 uintptr_t p; 1762 1763 for (note = (const Elf_Note *)note_start; (Elf_Addr)note < note_end; 1764 note = (const Elf_Note *)((const char *)(note + 1) + 1765 roundup2(note->n_namesz, sizeof(Elf32_Addr)) + 1766 roundup2(note->n_descsz, sizeof(Elf32_Addr)))) { 1767 if (arch_digest_note(obj, note)) 1768 continue; 1769 1770 if (note->n_namesz != sizeof(NOTE_FREEBSD_VENDOR) || 1771 note->n_descsz != sizeof(int32_t)) 1772 continue; 1773 if (note->n_type != NT_FREEBSD_ABI_TAG && 1774 note->n_type != NT_FREEBSD_FEATURE_CTL && 1775 note->n_type != NT_FREEBSD_NOINIT_TAG) 1776 continue; 1777 note_name = (const char *)(note + 1); 1778 if (strncmp(NOTE_FREEBSD_VENDOR, note_name, 1779 sizeof(NOTE_FREEBSD_VENDOR)) != 0) 1780 continue; 1781 switch (note->n_type) { 1782 case NT_FREEBSD_ABI_TAG: 1783 /* FreeBSD osrel note */ 1784 p = (uintptr_t)(note + 1); 1785 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1786 obj->osrel = *(const int32_t *)(p); 1787 dbg("note osrel %d", obj->osrel); 1788 break; 1789 case NT_FREEBSD_FEATURE_CTL: 1790 /* FreeBSD ABI feature control note */ 1791 p = (uintptr_t)(note + 1); 1792 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1793 obj->fctl0 = *(const uint32_t *)(p); 1794 dbg("note fctl0 %#x", obj->fctl0); 1795 break; 1796 case NT_FREEBSD_NOINIT_TAG: 1797 /* FreeBSD 'crt does not call init' note */ 1798 obj->crt_no_init = true; 1799 dbg("note crt_no_init"); 1800 break; 1801 } 1802 } 1803 } 1804 1805 static Obj_Entry * 1806 dlcheck(void *handle) 1807 { 1808 Obj_Entry *obj; 1809 1810 TAILQ_FOREACH(obj, &obj_list, next) { 1811 if (obj == (Obj_Entry *)handle) 1812 break; 1813 } 1814 1815 if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) { 1816 _rtld_error("Invalid shared object handle %p", handle); 1817 return (NULL); 1818 } 1819 return (obj); 1820 } 1821 1822 /* 1823 * If the given object is already in the donelist, return true. Otherwise 1824 * add the object to the list and return false. 1825 */ 1826 static bool 1827 donelist_check(DoneList *dlp, const Obj_Entry *obj) 1828 { 1829 unsigned int i; 1830 1831 for (i = 0; i < dlp->num_used; i++) 1832 if (dlp->objs[i] == obj) 1833 return (true); 1834 /* 1835 * Our donelist allocation should always be sufficient. But if 1836 * our threads locking isn't working properly, more shared objects 1837 * could have been loaded since we allocated the list. That should 1838 * never happen, but we'll handle it properly just in case it does. 1839 */ 1840 if (dlp->num_used < dlp->num_alloc) 1841 dlp->objs[dlp->num_used++] = obj; 1842 return (false); 1843 } 1844 1845 /* 1846 * SysV hash function for symbol table lookup. It is a slightly optimized 1847 * version of the hash specified by the System V ABI. 1848 */ 1849 Elf32_Word 1850 elf_hash(const char *name) 1851 { 1852 const unsigned char *p = (const unsigned char *)name; 1853 Elf32_Word h = 0; 1854 1855 while (*p != '\0') { 1856 h = (h << 4) + *p++; 1857 h ^= (h >> 24) & 0xf0; 1858 } 1859 return (h & 0x0fffffff); 1860 } 1861 1862 /* 1863 * The GNU hash function is the Daniel J. Bernstein hash clipped to 32 bits 1864 * unsigned in case it's implemented with a wider type. 1865 */ 1866 static uint32_t 1867 gnu_hash(const char *s) 1868 { 1869 uint32_t h; 1870 unsigned char c; 1871 1872 h = 5381; 1873 for (c = *s; c != '\0'; c = *++s) 1874 h = h * 33 + c; 1875 return (h & 0xffffffff); 1876 } 1877 1878 /* 1879 * Find the library with the given name, and return its full pathname. 1880 * The returned string is dynamically allocated. Generates an error 1881 * message and returns NULL if the library cannot be found. 1882 * 1883 * If the second argument is non-NULL, then it refers to an already- 1884 * loaded shared object, whose library search path will be searched. 1885 * 1886 * If a library is successfully located via LD_LIBRARY_PATH_FDS, its 1887 * descriptor (which is close-on-exec) will be passed out via the third 1888 * argument. 1889 * 1890 * The search order is: 1891 * DT_RPATH in the referencing file _unless_ DT_RUNPATH is present (1) 1892 * DT_RPATH of the main object if DSO without defined DT_RUNPATH (1) 1893 * LD_LIBRARY_PATH 1894 * DT_RUNPATH in the referencing file 1895 * ldconfig hints (if -z nodefaultlib, filter out default library directories 1896 * from list) 1897 * /lib:/usr/lib _unless_ the referencing file is linked with -z nodefaultlib 1898 * 1899 * (1) Handled in digest_dynamic2 - rpath left NULL if runpath defined. 1900 */ 1901 static char * 1902 find_library(const char *xname, const Obj_Entry *refobj, int *fdp) 1903 { 1904 char *pathname, *refobj_path; 1905 const char *name; 1906 bool nodeflib, objgiven; 1907 1908 objgiven = refobj != NULL; 1909 1910 if (libmap_disable || !objgiven || 1911 (name = lm_find(refobj->path, xname)) == NULL) 1912 name = xname; 1913 1914 if (strchr(name, '/') != NULL) { /* Hard coded pathname */ 1915 if (name[0] != '/' && !trust) { 1916 _rtld_error( 1917 "Absolute pathname required for shared object \"%s\"", 1918 name); 1919 return (NULL); 1920 } 1921 return (origin_subst(__DECONST(Obj_Entry *, refobj), 1922 __DECONST(char *, name))); 1923 } 1924 1925 dbg(" Searching for \"%s\"", name); 1926 refobj_path = objgiven ? refobj->path : NULL; 1927 1928 /* 1929 * If refobj->rpath != NULL, then refobj->runpath is NULL. Fall 1930 * back to pre-conforming behaviour if user requested so with 1931 * LD_LIBRARY_PATH_RPATH environment variable and ignore -z 1932 * nodeflib. 1933 */ 1934 if (objgiven && refobj->rpath != NULL && ld_library_path_rpath) { 1935 pathname = search_library_path(name, ld_library_path, 1936 refobj_path, fdp); 1937 if (pathname != NULL) 1938 return (pathname); 1939 if (refobj != NULL) { 1940 pathname = search_library_path(name, refobj->rpath, 1941 refobj_path, fdp); 1942 if (pathname != NULL) 1943 return (pathname); 1944 } 1945 pathname = search_library_pathfds(name, ld_library_dirs, fdp); 1946 if (pathname != NULL) 1947 return (pathname); 1948 pathname = search_library_path(name, gethints(false), 1949 refobj_path, fdp); 1950 if (pathname != NULL) 1951 return (pathname); 1952 pathname = search_library_path(name, ld_standard_library_path, 1953 refobj_path, fdp); 1954 if (pathname != NULL) 1955 return (pathname); 1956 } else { 1957 nodeflib = objgiven ? refobj->z_nodeflib : false; 1958 if (objgiven) { 1959 pathname = search_library_path(name, refobj->rpath, 1960 refobj->path, fdp); 1961 if (pathname != NULL) 1962 return (pathname); 1963 } 1964 if (objgiven && refobj->runpath == NULL && refobj != obj_main) { 1965 pathname = search_library_path(name, obj_main->rpath, 1966 refobj_path, fdp); 1967 if (pathname != NULL) 1968 return (pathname); 1969 } 1970 pathname = search_library_path(name, ld_library_path, 1971 refobj_path, fdp); 1972 if (pathname != NULL) 1973 return (pathname); 1974 if (objgiven) { 1975 pathname = search_library_path(name, refobj->runpath, 1976 refobj_path, fdp); 1977 if (pathname != NULL) 1978 return (pathname); 1979 } 1980 pathname = search_library_pathfds(name, ld_library_dirs, fdp); 1981 if (pathname != NULL) 1982 return (pathname); 1983 pathname = search_library_path(name, gethints(nodeflib), 1984 refobj_path, fdp); 1985 if (pathname != NULL) 1986 return (pathname); 1987 if (objgiven && !nodeflib) { 1988 pathname = search_library_path(name, 1989 ld_standard_library_path, refobj_path, fdp); 1990 if (pathname != NULL) 1991 return (pathname); 1992 } 1993 } 1994 1995 if (objgiven && refobj->path != NULL) { 1996 _rtld_error( 1997 "Shared object \"%s\" not found, required by \"%s\"", 1998 name, basename(refobj->path)); 1999 } else { 2000 _rtld_error("Shared object \"%s\" not found", name); 2001 } 2002 return (NULL); 2003 } 2004 2005 /* 2006 * Given a symbol number in a referencing object, find the corresponding 2007 * definition of the symbol. Returns a pointer to the symbol, or NULL if 2008 * no definition was found. Returns a pointer to the Obj_Entry of the 2009 * defining object via the reference parameter DEFOBJ_OUT. 2010 */ 2011 const Elf_Sym * 2012 find_symdef(unsigned long symnum, const Obj_Entry *refobj, 2013 const Obj_Entry **defobj_out, int flags, SymCache *cache, 2014 RtldLockState *lockstate) 2015 { 2016 const Elf_Sym *ref; 2017 const Elf_Sym *def; 2018 const Obj_Entry *defobj; 2019 const Ver_Entry *ve; 2020 SymLook req; 2021 const char *name; 2022 int res; 2023 2024 /* 2025 * If we have already found this symbol, get the information from 2026 * the cache. 2027 */ 2028 if (symnum >= refobj->dynsymcount) 2029 return (NULL); /* Bad object */ 2030 if (cache != NULL && cache[symnum].sym != NULL) { 2031 *defobj_out = cache[symnum].obj; 2032 return (cache[symnum].sym); 2033 } 2034 2035 ref = refobj->symtab + symnum; 2036 name = refobj->strtab + ref->st_name; 2037 def = NULL; 2038 defobj = NULL; 2039 ve = NULL; 2040 2041 /* 2042 * We don't have to do a full scale lookup if the symbol is local. 2043 * We know it will bind to the instance in this load module; to 2044 * which we already have a pointer (ie ref). By not doing a lookup, 2045 * we not only improve performance, but it also avoids unresolvable 2046 * symbols when local symbols are not in the hash table. This has 2047 * been seen with the ia64 toolchain. 2048 */ 2049 if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) { 2050 if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) { 2051 _rtld_error("%s: Bogus symbol table entry %lu", 2052 refobj->path, symnum); 2053 } 2054 symlook_init(&req, name); 2055 req.flags = flags; 2056 ve = req.ventry = fetch_ventry(refobj, symnum); 2057 req.lockstate = lockstate; 2058 res = symlook_default(&req, refobj); 2059 if (res == 0) { 2060 def = req.sym_out; 2061 defobj = req.defobj_out; 2062 } 2063 } else { 2064 def = ref; 2065 defobj = refobj; 2066 } 2067 2068 /* 2069 * If we found no definition and the reference is weak, treat the 2070 * symbol as having the value zero. 2071 */ 2072 if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) { 2073 def = &sym_zero; 2074 defobj = obj_main; 2075 } 2076 2077 if (def != NULL) { 2078 *defobj_out = defobj; 2079 /* 2080 * Record the information in the cache to avoid subsequent 2081 * lookups. 2082 */ 2083 if (cache != NULL) { 2084 cache[symnum].sym = def; 2085 cache[symnum].obj = defobj; 2086 } 2087 } else { 2088 if (refobj != &obj_rtld) 2089 _rtld_error("%s: Undefined symbol \"%s%s%s\"", 2090 refobj->path, name, ve != NULL ? "@" : "", 2091 ve != NULL ? ve->name : ""); 2092 } 2093 return (def); 2094 } 2095 2096 /* Convert between native byte order and forced little resp. big endian. */ 2097 #define COND_SWAP(n) (is_le ? le32toh(n) : be32toh(n)) 2098 2099 /* 2100 * Return the search path from the ldconfig hints file, reading it if 2101 * necessary. If nostdlib is true, then the default search paths are 2102 * not added to result. 2103 * 2104 * Returns NULL if there are problems with the hints file, 2105 * or if the search path there is empty. 2106 */ 2107 static const char * 2108 gethints(bool nostdlib) 2109 { 2110 static char *filtered_path; 2111 static const char *hints; 2112 static struct elfhints_hdr hdr; 2113 struct fill_search_info_args sargs, hargs; 2114 struct dl_serinfo smeta, hmeta, *SLPinfo, *hintinfo; 2115 struct dl_serpath *SLPpath, *hintpath; 2116 char *p; 2117 struct stat hint_stat; 2118 unsigned int SLPndx, hintndx, fndx, fcount; 2119 int fd; 2120 size_t flen; 2121 uint32_t dl; 2122 uint32_t magic; /* Magic number */ 2123 uint32_t version; /* File version (1) */ 2124 uint32_t strtab; /* Offset of string table in file */ 2125 uint32_t dirlist; /* Offset of directory list in string table */ 2126 uint32_t dirlistlen; /* strlen(dirlist) */ 2127 bool is_le; /* Does the hints file use little endian */ 2128 bool skip; 2129 2130 /* First call, read the hints file */ 2131 if (hints == NULL) { 2132 /* Keep from trying again in case the hints file is bad. */ 2133 hints = ""; 2134 2135 if ((fd = open(ld_elf_hints_path, O_RDONLY | O_CLOEXEC)) == 2136 -1) { 2137 dbg("failed to open hints file \"%s\"", 2138 ld_elf_hints_path); 2139 return (NULL); 2140 } 2141 2142 /* 2143 * Check of hdr.dirlistlen value against type limit 2144 * intends to pacify static analyzers. Further 2145 * paranoia leads to checks that dirlist is fully 2146 * contained in the file range. 2147 */ 2148 if (read(fd, &hdr, sizeof hdr) != sizeof hdr) { 2149 dbg("failed to read %lu bytes from hints file \"%s\"", 2150 (u_long)sizeof hdr, ld_elf_hints_path); 2151 cleanup1: 2152 close(fd); 2153 hdr.dirlistlen = 0; 2154 return (NULL); 2155 } 2156 dbg("host byte-order: %s-endian", 2157 le32toh(1) == 1 ? "little" : "big"); 2158 dbg("hints file byte-order: %s-endian", 2159 hdr.magic == htole32(ELFHINTS_MAGIC) ? "little" : "big"); 2160 is_le = /*htole32(1) == 1 || */ hdr.magic == 2161 htole32(ELFHINTS_MAGIC); 2162 magic = COND_SWAP(hdr.magic); 2163 version = COND_SWAP(hdr.version); 2164 strtab = COND_SWAP(hdr.strtab); 2165 dirlist = COND_SWAP(hdr.dirlist); 2166 dirlistlen = COND_SWAP(hdr.dirlistlen); 2167 if (magic != ELFHINTS_MAGIC) { 2168 dbg("invalid magic number %#08x (expected: %#08x)", 2169 magic, ELFHINTS_MAGIC); 2170 goto cleanup1; 2171 } 2172 if (version != 1) { 2173 dbg("hints file version %d (expected: 1)", version); 2174 goto cleanup1; 2175 } 2176 if (dirlistlen > UINT_MAX / 2) { 2177 dbg("directory list is to long: %d > %d", dirlistlen, 2178 UINT_MAX / 2); 2179 goto cleanup1; 2180 } 2181 if (fstat(fd, &hint_stat) == -1) { 2182 dbg("failed to find length of hints file \"%s\"", 2183 ld_elf_hints_path); 2184 goto cleanup1; 2185 } 2186 dl = strtab; 2187 if (dl + dirlist < dl) { 2188 dbg("invalid string table position %d", dl); 2189 goto cleanup1; 2190 } 2191 dl += dirlist; 2192 if (dl + dirlistlen < dl) { 2193 dbg("invalid directory list offset %d", dirlist); 2194 goto cleanup1; 2195 } 2196 dl += dirlistlen; 2197 if (dl > hint_stat.st_size) { 2198 dbg("hints file \"%s\" is truncated (%d vs. %jd bytes)", 2199 ld_elf_hints_path, dl, 2200 (uintmax_t)hint_stat.st_size); 2201 goto cleanup1; 2202 } 2203 p = xmalloc(dirlistlen + 1); 2204 if (pread(fd, p, dirlistlen + 1, strtab + dirlist) != 2205 (ssize_t)dirlistlen + 1 || p[dirlistlen] != '\0') { 2206 free(p); 2207 dbg( 2208 "failed to read %d bytes starting at %d from hints file \"%s\"", 2209 dirlistlen + 1, strtab + dirlist, 2210 ld_elf_hints_path); 2211 goto cleanup1; 2212 } 2213 hints = p; 2214 close(fd); 2215 } 2216 2217 /* 2218 * If caller agreed to receive list which includes the default 2219 * paths, we are done. Otherwise, if we still did not 2220 * calculated filtered result, do it now. 2221 */ 2222 if (!nostdlib) 2223 return (hints[0] != '\0' ? hints : NULL); 2224 if (filtered_path != NULL) 2225 goto filt_ret; 2226 2227 /* 2228 * Obtain the list of all configured search paths, and the 2229 * list of the default paths. 2230 * 2231 * First estimate the size of the results. 2232 */ 2233 smeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 2234 smeta.dls_cnt = 0; 2235 hmeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 2236 hmeta.dls_cnt = 0; 2237 2238 sargs.request = RTLD_DI_SERINFOSIZE; 2239 sargs.serinfo = &smeta; 2240 hargs.request = RTLD_DI_SERINFOSIZE; 2241 hargs.serinfo = &hmeta; 2242 2243 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 2244 &sargs); 2245 path_enumerate(hints, fill_search_info, NULL, &hargs); 2246 2247 SLPinfo = xmalloc(smeta.dls_size); 2248 hintinfo = xmalloc(hmeta.dls_size); 2249 2250 /* 2251 * Next fetch both sets of paths. 2252 */ 2253 sargs.request = RTLD_DI_SERINFO; 2254 sargs.serinfo = SLPinfo; 2255 sargs.serpath = &SLPinfo->dls_serpath[0]; 2256 sargs.strspace = (char *)&SLPinfo->dls_serpath[smeta.dls_cnt]; 2257 2258 hargs.request = RTLD_DI_SERINFO; 2259 hargs.serinfo = hintinfo; 2260 hargs.serpath = &hintinfo->dls_serpath[0]; 2261 hargs.strspace = (char *)&hintinfo->dls_serpath[hmeta.dls_cnt]; 2262 2263 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 2264 &sargs); 2265 path_enumerate(hints, fill_search_info, NULL, &hargs); 2266 2267 /* 2268 * Now calculate the difference between two sets, by excluding 2269 * standard paths from the full set. 2270 */ 2271 fndx = 0; 2272 fcount = 0; 2273 filtered_path = xmalloc(dirlistlen + 1); 2274 hintpath = &hintinfo->dls_serpath[0]; 2275 for (hintndx = 0; hintndx < hmeta.dls_cnt; hintndx++, hintpath++) { 2276 skip = false; 2277 SLPpath = &SLPinfo->dls_serpath[0]; 2278 /* 2279 * Check each standard path against current. 2280 */ 2281 for (SLPndx = 0; SLPndx < smeta.dls_cnt; SLPndx++, SLPpath++) { 2282 /* matched, skip the path */ 2283 if (!strcmp(hintpath->dls_name, SLPpath->dls_name)) { 2284 skip = true; 2285 break; 2286 } 2287 } 2288 if (skip) 2289 continue; 2290 /* 2291 * Not matched against any standard path, add the path 2292 * to result. Separate consequtive paths with ':'. 2293 */ 2294 if (fcount > 0) { 2295 filtered_path[fndx] = ':'; 2296 fndx++; 2297 } 2298 fcount++; 2299 flen = strlen(hintpath->dls_name); 2300 strncpy((filtered_path + fndx), hintpath->dls_name, flen); 2301 fndx += flen; 2302 } 2303 filtered_path[fndx] = '\0'; 2304 2305 free(SLPinfo); 2306 free(hintinfo); 2307 2308 filt_ret: 2309 return (filtered_path[0] != '\0' ? filtered_path : NULL); 2310 } 2311 2312 static void 2313 init_dag(Obj_Entry *root) 2314 { 2315 const Needed_Entry *needed; 2316 const Objlist_Entry *elm; 2317 DoneList donelist; 2318 2319 if (root->dag_inited) 2320 return; 2321 donelist_init(&donelist); 2322 2323 /* Root object belongs to own DAG. */ 2324 objlist_push_tail(&root->dldags, root); 2325 objlist_push_tail(&root->dagmembers, root); 2326 donelist_check(&donelist, root); 2327 2328 /* 2329 * Add dependencies of root object to DAG in breadth order 2330 * by exploiting the fact that each new object get added 2331 * to the tail of the dagmembers list. 2332 */ 2333 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2334 for (needed = elm->obj->needed; needed != NULL; 2335 needed = needed->next) { 2336 if (needed->obj == NULL || 2337 donelist_check(&donelist, needed->obj)) 2338 continue; 2339 objlist_push_tail(&needed->obj->dldags, root); 2340 objlist_push_tail(&root->dagmembers, needed->obj); 2341 } 2342 } 2343 root->dag_inited = true; 2344 } 2345 2346 static void 2347 init_marker(Obj_Entry *marker) 2348 { 2349 bzero(marker, sizeof(*marker)); 2350 marker->marker = true; 2351 } 2352 2353 Obj_Entry * 2354 globallist_curr(const Obj_Entry *obj) 2355 { 2356 for (;;) { 2357 if (obj == NULL) 2358 return (NULL); 2359 if (!obj->marker) 2360 return (__DECONST(Obj_Entry *, obj)); 2361 obj = TAILQ_PREV(obj, obj_entry_q, next); 2362 } 2363 } 2364 2365 Obj_Entry * 2366 globallist_next(const Obj_Entry *obj) 2367 { 2368 for (;;) { 2369 obj = TAILQ_NEXT(obj, next); 2370 if (obj == NULL) 2371 return (NULL); 2372 if (!obj->marker) 2373 return (__DECONST(Obj_Entry *, obj)); 2374 } 2375 } 2376 2377 /* Prevent the object from being unmapped while the bind lock is dropped. */ 2378 static void 2379 hold_object(Obj_Entry *obj) 2380 { 2381 obj->holdcount++; 2382 } 2383 2384 static void 2385 unhold_object(Obj_Entry *obj) 2386 { 2387 assert(obj->holdcount > 0); 2388 if (--obj->holdcount == 0 && obj->unholdfree) 2389 release_object(obj); 2390 } 2391 2392 static void 2393 process_z(Obj_Entry *root) 2394 { 2395 const Objlist_Entry *elm; 2396 Obj_Entry *obj; 2397 2398 /* 2399 * Walk over object DAG and process every dependent object 2400 * that is marked as DF_1_NODELETE or DF_1_GLOBAL. They need 2401 * to grow their own DAG. 2402 * 2403 * For DF_1_GLOBAL, DAG is required for symbol lookups in 2404 * symlook_global() to work. 2405 * 2406 * For DF_1_NODELETE, the DAG should have its reference upped. 2407 */ 2408 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2409 obj = elm->obj; 2410 if (obj == NULL) 2411 continue; 2412 if (obj->z_nodelete && !obj->ref_nodel) { 2413 dbg("obj %s -z nodelete", obj->path); 2414 init_dag(obj); 2415 ref_dag(obj); 2416 obj->ref_nodel = true; 2417 } 2418 if (obj->z_global && objlist_find(&list_global, obj) == NULL) { 2419 dbg("obj %s -z global", obj->path); 2420 objlist_push_tail(&list_global, obj); 2421 init_dag(obj); 2422 } 2423 } 2424 } 2425 2426 static void 2427 parse_rtld_phdr(Obj_Entry *obj) 2428 { 2429 const Elf_Phdr *ph; 2430 Elf_Addr note_start, note_end; 2431 bool first_seg; 2432 2433 first_seg = true; 2434 obj->stack_flags = PF_X | PF_R | PF_W; 2435 for (ph = obj->phdr; ph < obj->phdr + obj->phnum; ph++) { 2436 switch (ph->p_type) { 2437 case PT_LOAD: 2438 if (first_seg) { 2439 obj->vaddrbase = rtld_trunc_page(ph->p_vaddr); 2440 first_seg = false; 2441 } 2442 obj->mapsize = rtld_round_page(ph->p_vaddr + 2443 ph->p_memsz) - obj->vaddrbase; 2444 break; 2445 case PT_GNU_STACK: 2446 obj->stack_flags = ph->p_flags; 2447 break; 2448 case PT_NOTE: 2449 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; 2450 note_end = note_start + ph->p_filesz; 2451 digest_notes(obj, note_start, note_end); 2452 break; 2453 } 2454 } 2455 } 2456 2457 /* 2458 * Initialize the dynamic linker. The argument is the address at which 2459 * the dynamic linker has been mapped into memory. The primary task of 2460 * this function is to relocate the dynamic linker. 2461 */ 2462 static void 2463 init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info) 2464 { 2465 Obj_Entry objtmp; /* Temporary rtld object */ 2466 const Elf_Ehdr *ehdr; 2467 const Elf_Dyn *dyn_rpath; 2468 const Elf_Dyn *dyn_soname; 2469 const Elf_Dyn *dyn_runpath; 2470 2471 /* 2472 * Conjure up an Obj_Entry structure for the dynamic linker. 2473 * 2474 * The "path" member can't be initialized yet because string constants 2475 * cannot yet be accessed. Below we will set it correctly. 2476 */ 2477 memset(&objtmp, 0, sizeof(objtmp)); 2478 objtmp.path = NULL; 2479 objtmp.rtld = true; 2480 objtmp.mapbase = mapbase; 2481 #ifdef PIC 2482 objtmp.relocbase = mapbase; 2483 #endif 2484 2485 objtmp.dynamic = rtld_dynamic(&objtmp); 2486 digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname, &dyn_runpath); 2487 assert(objtmp.needed == NULL); 2488 assert(!objtmp.textrel); 2489 /* 2490 * Temporarily put the dynamic linker entry into the object list, so 2491 * that symbols can be found. 2492 */ 2493 relocate_objects(&objtmp, true, &objtmp, 0, NULL); 2494 2495 ehdr = (Elf_Ehdr *)mapbase; 2496 objtmp.phdr = (Elf_Phdr *)((char *)mapbase + ehdr->e_phoff); 2497 objtmp.phnum = ehdr->e_phnum; 2498 2499 /* Initialize the object list. */ 2500 TAILQ_INIT(&obj_list); 2501 2502 /* Now that non-local variables can be accesses, copy out obj_rtld. */ 2503 memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld)); 2504 2505 /* The page size is required by the dynamic memory allocator. */ 2506 init_pagesizes(aux_info); 2507 2508 if (aux_info[AT_OSRELDATE] != NULL) 2509 osreldate = aux_info[AT_OSRELDATE]->a_un.a_val; 2510 2511 digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname, dyn_runpath); 2512 2513 /* Replace the path with a dynamically allocated copy. */ 2514 obj_rtld.path = xstrdup(ld_path_rtld); 2515 2516 parse_rtld_phdr(&obj_rtld); 2517 if (obj_enforce_relro(&obj_rtld) == -1) 2518 rtld_die(); 2519 2520 r_debug.r_version = R_DEBUG_VERSION; 2521 r_debug.r_brk = r_debug_state; 2522 r_debug.r_state = RT_CONSISTENT; 2523 r_debug.r_ldbase = obj_rtld.relocbase; 2524 } 2525 2526 /* 2527 * Retrieve the array of supported page sizes. The kernel provides the page 2528 * sizes in increasing order. 2529 */ 2530 static void 2531 init_pagesizes(Elf_Auxinfo **aux_info) 2532 { 2533 static size_t psa[MAXPAGESIZES]; 2534 int mib[2]; 2535 size_t len, size; 2536 2537 if (aux_info[AT_PAGESIZES] != NULL && 2538 aux_info[AT_PAGESIZESLEN] != NULL) { 2539 size = aux_info[AT_PAGESIZESLEN]->a_un.a_val; 2540 pagesizes = aux_info[AT_PAGESIZES]->a_un.a_ptr; 2541 } else { 2542 len = 2; 2543 if (sysctlnametomib("hw.pagesizes", mib, &len) == 0) 2544 size = sizeof(psa); 2545 else { 2546 /* As a fallback, retrieve the base page size. */ 2547 size = sizeof(psa[0]); 2548 if (aux_info[AT_PAGESZ] != NULL) { 2549 psa[0] = aux_info[AT_PAGESZ]->a_un.a_val; 2550 goto psa_filled; 2551 } else { 2552 mib[0] = CTL_HW; 2553 mib[1] = HW_PAGESIZE; 2554 len = 2; 2555 } 2556 } 2557 if (sysctl(mib, len, psa, &size, NULL, 0) == -1) { 2558 _rtld_error("sysctl for hw.pagesize(s) failed"); 2559 rtld_die(); 2560 } 2561 psa_filled: 2562 pagesizes = psa; 2563 } 2564 npagesizes = size / sizeof(pagesizes[0]); 2565 /* Discard any invalid entries at the end of the array. */ 2566 while (npagesizes > 0 && pagesizes[npagesizes - 1] == 0) 2567 npagesizes--; 2568 2569 page_size = pagesizes[0]; 2570 } 2571 2572 /* 2573 * Add the init functions from a needed object list (and its recursive 2574 * needed objects) to "list". This is not used directly; it is a helper 2575 * function for initlist_add_objects(). The write lock must be held 2576 * when this function is called. 2577 */ 2578 static void 2579 initlist_add_neededs(Needed_Entry *needed, Objlist *list, Objlist *iflist) 2580 { 2581 /* Recursively process the successor needed objects. */ 2582 if (needed->next != NULL) 2583 initlist_add_neededs(needed->next, list, iflist); 2584 2585 /* Process the current needed object. */ 2586 if (needed->obj != NULL) 2587 initlist_add_objects(needed->obj, needed->obj, list, iflist); 2588 } 2589 2590 /* 2591 * Scan all of the DAGs rooted in the range of objects from "obj" to 2592 * "tail" and add their init functions to "list". This recurses over 2593 * the DAGs and ensure the proper init ordering such that each object's 2594 * needed libraries are initialized before the object itself. At the 2595 * same time, this function adds the objects to the global finalization 2596 * list "list_fini" in the opposite order. The write lock must be 2597 * held when this function is called. 2598 */ 2599 static void 2600 initlist_for_loaded_obj(Obj_Entry *obj, Obj_Entry *tail, Objlist *list) 2601 { 2602 Objlist iflist; /* initfirst objs and their needed */ 2603 Objlist_Entry *tmp; 2604 2605 objlist_init(&iflist); 2606 initlist_add_objects(obj, tail, list, &iflist); 2607 2608 STAILQ_FOREACH(tmp, &iflist, link) { 2609 Obj_Entry *tobj = tmp->obj; 2610 2611 if ((tobj->fini != 0 || tobj->fini_array != NULL) && 2612 !tobj->on_fini_list) { 2613 objlist_push_tail(&list_fini, tobj); 2614 tobj->on_fini_list = true; 2615 } 2616 } 2617 2618 /* 2619 * This might result in the same object appearing more 2620 * than once on the init list. objlist_call_init() 2621 * uses obj->init_scanned to avoid dup calls. 2622 */ 2623 STAILQ_REVERSE(&iflist, Struct_Objlist_Entry, link); 2624 STAILQ_FOREACH(tmp, &iflist, link) 2625 objlist_push_head(list, tmp->obj); 2626 2627 objlist_clear(&iflist); 2628 } 2629 2630 static void 2631 initlist_add_objects(Obj_Entry *obj, Obj_Entry *tail, Objlist *list, 2632 Objlist *iflist) 2633 { 2634 Obj_Entry *nobj; 2635 2636 if (obj->init_done) 2637 return; 2638 2639 if (obj->z_initfirst || list == NULL) { 2640 /* 2641 * Ignore obj->init_scanned. The object might indeed 2642 * already be on the init list, but due to being 2643 * needed by an initfirst object, we must put it at 2644 * the head of the init list. obj->init_done protects 2645 * against double-initialization. 2646 */ 2647 if (obj->needed != NULL) 2648 initlist_add_neededs(obj->needed, NULL, iflist); 2649 if (obj->needed_filtees != NULL) 2650 initlist_add_neededs(obj->needed_filtees, NULL, 2651 iflist); 2652 if (obj->needed_aux_filtees != NULL) 2653 initlist_add_neededs(obj->needed_aux_filtees, 2654 NULL, iflist); 2655 objlist_push_tail(iflist, obj); 2656 } else { 2657 if (obj->init_scanned) 2658 return; 2659 obj->init_scanned = true; 2660 2661 /* Recursively process the successor objects. */ 2662 nobj = globallist_next(obj); 2663 if (nobj != NULL && obj != tail) 2664 initlist_add_objects(nobj, tail, list, iflist); 2665 2666 /* Recursively process the needed objects. */ 2667 if (obj->needed != NULL) 2668 initlist_add_neededs(obj->needed, list, iflist); 2669 if (obj->needed_filtees != NULL) 2670 initlist_add_neededs(obj->needed_filtees, list, 2671 iflist); 2672 if (obj->needed_aux_filtees != NULL) 2673 initlist_add_neededs(obj->needed_aux_filtees, list, 2674 iflist); 2675 2676 /* Add the object to the init list. */ 2677 objlist_push_tail(list, obj); 2678 2679 /* 2680 * Add the object to the global fini list in the 2681 * reverse order. 2682 */ 2683 if ((obj->fini != 0 || obj->fini_array != NULL) && 2684 !obj->on_fini_list) { 2685 objlist_push_head(&list_fini, obj); 2686 obj->on_fini_list = true; 2687 } 2688 } 2689 } 2690 2691 static void 2692 free_needed_filtees(Needed_Entry *n, RtldLockState *lockstate) 2693 { 2694 Needed_Entry *needed, *needed1; 2695 2696 for (needed = n; needed != NULL; needed = needed->next) { 2697 if (needed->obj != NULL) { 2698 dlclose_locked(needed->obj, lockstate); 2699 needed->obj = NULL; 2700 } 2701 } 2702 for (needed = n; needed != NULL; needed = needed1) { 2703 needed1 = needed->next; 2704 free(needed); 2705 } 2706 } 2707 2708 static void 2709 unload_filtees(Obj_Entry *obj, RtldLockState *lockstate) 2710 { 2711 free_needed_filtees(obj->needed_filtees, lockstate); 2712 obj->needed_filtees = NULL; 2713 free_needed_filtees(obj->needed_aux_filtees, lockstate); 2714 obj->needed_aux_filtees = NULL; 2715 obj->filtees_loaded = false; 2716 } 2717 2718 static void 2719 load_filtee1(Obj_Entry *obj, Needed_Entry *needed, int flags, 2720 RtldLockState *lockstate) 2721 { 2722 for (; needed != NULL; needed = needed->next) { 2723 needed->obj = dlopen_object(obj->strtab + needed->name, -1, obj, 2724 flags, ((ld_loadfltr || obj->z_loadfltr) ? RTLD_NOW : 2725 RTLD_LAZY) | RTLD_LOCAL, lockstate); 2726 } 2727 } 2728 2729 static void 2730 load_filtees(Obj_Entry *obj, int flags, RtldLockState *lockstate) 2731 { 2732 if (obj->filtees_loaded || obj->filtees_loading) 2733 return; 2734 lock_restart_for_upgrade(lockstate); 2735 obj->filtees_loading = true; 2736 load_filtee1(obj, obj->needed_filtees, flags, lockstate); 2737 load_filtee1(obj, obj->needed_aux_filtees, flags, lockstate); 2738 obj->filtees_loaded = true; 2739 obj->filtees_loading = false; 2740 } 2741 2742 static int 2743 process_needed(Obj_Entry *obj, Needed_Entry *needed, int flags) 2744 { 2745 Obj_Entry *obj1; 2746 2747 for (; needed != NULL; needed = needed->next) { 2748 obj1 = needed->obj = load_object(obj->strtab + needed->name, -1, 2749 obj, flags & ~RTLD_LO_NOLOAD); 2750 if (obj1 == NULL && !ld_tracing && 2751 (flags & RTLD_LO_FILTEES) == 0) 2752 return (-1); 2753 } 2754 return (0); 2755 } 2756 2757 /* 2758 * Given a shared object, traverse its list of needed objects, and load 2759 * each of them. Returns 0 on success. Generates an error message and 2760 * returns -1 on failure. 2761 */ 2762 static int 2763 load_needed_objects(Obj_Entry *first, int flags) 2764 { 2765 Obj_Entry *obj; 2766 2767 for (obj = first; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 2768 if (obj->marker) 2769 continue; 2770 if (process_needed(obj, obj->needed, flags) == -1) 2771 return (-1); 2772 } 2773 return (0); 2774 } 2775 2776 static int 2777 load_preload_objects(const char *penv, bool isfd) 2778 { 2779 Obj_Entry *obj; 2780 const char *name; 2781 size_t len; 2782 char savech, *p, *psave; 2783 int fd; 2784 static const char delim[] = " \t:;"; 2785 2786 if (penv == NULL) 2787 return (0); 2788 2789 p = psave = xstrdup(penv); 2790 p += strspn(p, delim); 2791 while (*p != '\0') { 2792 len = strcspn(p, delim); 2793 2794 savech = p[len]; 2795 p[len] = '\0'; 2796 if (isfd) { 2797 name = NULL; 2798 fd = parse_integer(p); 2799 if (fd == -1) { 2800 free(psave); 2801 return (-1); 2802 } 2803 } else { 2804 name = p; 2805 fd = -1; 2806 } 2807 2808 obj = load_object(name, fd, NULL, 0); 2809 if (obj == NULL) { 2810 free(psave); 2811 return (-1); /* XXX - cleanup */ 2812 } 2813 obj->z_interpose = true; 2814 p[len] = savech; 2815 p += len; 2816 p += strspn(p, delim); 2817 } 2818 LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL); 2819 2820 free(psave); 2821 return (0); 2822 } 2823 2824 static const char * 2825 printable_path(const char *path) 2826 { 2827 return (path == NULL ? "<unknown>" : path); 2828 } 2829 2830 /* 2831 * Load a shared object into memory, if it is not already loaded. The 2832 * object may be specified by name or by user-supplied file descriptor 2833 * fd_u. In the later case, the fd_u descriptor is not closed, but its 2834 * duplicate is. 2835 * 2836 * Returns a pointer to the Obj_Entry for the object. Returns NULL 2837 * on failure. 2838 */ 2839 static Obj_Entry * 2840 load_object(const char *name, int fd_u, const Obj_Entry *refobj, int flags) 2841 { 2842 Obj_Entry *obj; 2843 int fd; 2844 struct stat sb; 2845 char *path; 2846 2847 fd = -1; 2848 if (name != NULL) { 2849 TAILQ_FOREACH(obj, &obj_list, next) { 2850 if (obj->marker || obj->doomed) 2851 continue; 2852 if (object_match_name(obj, name)) 2853 return (obj); 2854 } 2855 2856 path = find_library(name, refobj, &fd); 2857 if (path == NULL) 2858 return (NULL); 2859 } else 2860 path = NULL; 2861 2862 if (fd >= 0) { 2863 /* 2864 * search_library_pathfds() opens a fresh file descriptor for 2865 * the library, so there is no need to dup(). 2866 */ 2867 } else if (fd_u == -1) { 2868 /* 2869 * If we didn't find a match by pathname, or the name is not 2870 * supplied, open the file and check again by device and inode. 2871 * This avoids false mismatches caused by multiple links or ".." 2872 * in pathnames. 2873 * 2874 * To avoid a race, we open the file and use fstat() rather than 2875 * using stat(). 2876 */ 2877 if ((fd = open(path, O_RDONLY | O_CLOEXEC | O_VERIFY)) == -1) { 2878 _rtld_error("Cannot open \"%s\"", path); 2879 free(path); 2880 return (NULL); 2881 } 2882 } else { 2883 fd = fcntl(fd_u, F_DUPFD_CLOEXEC, 0); 2884 if (fd == -1) { 2885 _rtld_error("Cannot dup fd"); 2886 free(path); 2887 return (NULL); 2888 } 2889 } 2890 if (fstat(fd, &sb) == -1) { 2891 _rtld_error("Cannot fstat \"%s\"", printable_path(path)); 2892 close(fd); 2893 free(path); 2894 return (NULL); 2895 } 2896 TAILQ_FOREACH(obj, &obj_list, next) { 2897 if (obj->marker || obj->doomed) 2898 continue; 2899 if (obj->ino == sb.st_ino && obj->dev == sb.st_dev) 2900 break; 2901 } 2902 if (obj != NULL) { 2903 if (name != NULL) 2904 object_add_name(obj, name); 2905 free(path); 2906 close(fd); 2907 return (obj); 2908 } 2909 if (flags & RTLD_LO_NOLOAD) { 2910 free(path); 2911 close(fd); 2912 return (NULL); 2913 } 2914 2915 /* First use of this object, so we must map it in */ 2916 obj = do_load_object(fd, name, path, &sb, flags); 2917 if (obj == NULL) 2918 free(path); 2919 close(fd); 2920 2921 return (obj); 2922 } 2923 2924 static Obj_Entry * 2925 do_load_object(int fd, const char *name, char *path, struct stat *sbp, 2926 int flags) 2927 { 2928 Obj_Entry *obj; 2929 struct statfs fs; 2930 2931 /* 2932 * First, make sure that environment variables haven't been 2933 * used to circumvent the noexec flag on a filesystem. 2934 * We ignore fstatfs(2) failures, since fd might reference 2935 * not a file, e.g. shmfd. 2936 */ 2937 if (dangerous_ld_env && fstatfs(fd, &fs) == 0 && 2938 (fs.f_flags & MNT_NOEXEC) != 0) { 2939 _rtld_error("Cannot execute objects on %s", fs.f_mntonname); 2940 return (NULL); 2941 } 2942 2943 dbg("loading \"%s\"", printable_path(path)); 2944 obj = map_object(fd, printable_path(path), sbp, false); 2945 if (obj == NULL) 2946 return (NULL); 2947 2948 /* 2949 * If DT_SONAME is present in the object, digest_dynamic2 already 2950 * added it to the object names. 2951 */ 2952 if (name != NULL) 2953 object_add_name(obj, name); 2954 obj->path = path; 2955 if (!digest_dynamic(obj, 0)) 2956 goto errp; 2957 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", obj->path, 2958 obj->valid_hash_sysv, obj->valid_hash_gnu, obj->dynsymcount); 2959 if (obj->z_pie && (flags & RTLD_LO_TRACE) == 0) { 2960 dbg("refusing to load PIE executable \"%s\"", obj->path); 2961 _rtld_error("Cannot load PIE binary %s as DSO", obj->path); 2962 goto errp; 2963 } 2964 if (obj->z_noopen && 2965 (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) == RTLD_LO_DLOPEN) { 2966 dbg("refusing to load non-loadable \"%s\"", obj->path); 2967 _rtld_error("Cannot dlopen non-loadable %s", obj->path); 2968 goto errp; 2969 } 2970 2971 obj->dlopened = (flags & RTLD_LO_DLOPEN) != 0; 2972 TAILQ_INSERT_TAIL(&obj_list, obj, next); 2973 obj_count++; 2974 obj_loads++; 2975 linkmap_add(obj); /* for GDB & dlinfo() */ 2976 max_stack_flags |= obj->stack_flags; 2977 2978 dbg(" %p .. %p: %s", obj->mapbase, obj->mapbase + obj->mapsize - 1, 2979 obj->path); 2980 if (obj->textrel) 2981 dbg(" WARNING: %s has impure text", obj->path); 2982 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 2983 obj->path); 2984 2985 return (obj); 2986 2987 errp: 2988 munmap(obj->mapbase, obj->mapsize); 2989 obj_free(obj); 2990 return (NULL); 2991 } 2992 2993 static int 2994 load_kpreload(const void *addr) 2995 { 2996 Obj_Entry *obj; 2997 const Elf_Ehdr *ehdr; 2998 const Elf_Phdr *phdr, *phlimit, *phdyn, *seg0, *segn; 2999 static const char kname[] = "[vdso]"; 3000 3001 ehdr = addr; 3002 if (!check_elf_headers(ehdr, "kpreload")) 3003 return (-1); 3004 obj = obj_new(); 3005 phdr = (const Elf_Phdr *)((const char *)addr + ehdr->e_phoff); 3006 obj->phdr = phdr; 3007 obj->phnum = ehdr->e_phnum; 3008 phlimit = phdr + ehdr->e_phnum; 3009 seg0 = segn = NULL; 3010 3011 for (; phdr < phlimit; phdr++) { 3012 switch (phdr->p_type) { 3013 case PT_DYNAMIC: 3014 phdyn = phdr; 3015 break; 3016 case PT_GNU_STACK: 3017 /* Absense of PT_GNU_STACK implies stack_flags == 0. */ 3018 obj->stack_flags = phdr->p_flags; 3019 break; 3020 case PT_LOAD: 3021 if (seg0 == NULL || seg0->p_vaddr > phdr->p_vaddr) 3022 seg0 = phdr; 3023 if (segn == NULL || 3024 segn->p_vaddr + segn->p_memsz < 3025 phdr->p_vaddr + phdr->p_memsz) 3026 segn = phdr; 3027 break; 3028 } 3029 } 3030 3031 obj->mapbase = __DECONST(caddr_t, addr); 3032 obj->mapsize = segn->p_vaddr + segn->p_memsz; 3033 obj->vaddrbase = 0; 3034 obj->relocbase = obj->mapbase; 3035 3036 object_add_name(obj, kname); 3037 obj->path = xstrdup(kname); 3038 obj->dynamic = (const Elf_Dyn *)(obj->relocbase + phdyn->p_vaddr); 3039 3040 if (!digest_dynamic(obj, 0)) { 3041 obj_free(obj); 3042 return (-1); 3043 } 3044 3045 /* 3046 * We assume that kernel-preloaded object does not need 3047 * relocation. It is currently written into read-only page, 3048 * handling relocations would mean we need to allocate at 3049 * least one additional page per AS. 3050 */ 3051 dbg("%s mapbase %p phdrs %p PT_LOAD phdr %p vaddr %p dynamic %p", 3052 obj->path, obj->mapbase, obj->phdr, seg0, 3053 obj->relocbase + seg0->p_vaddr, obj->dynamic); 3054 3055 TAILQ_INSERT_TAIL(&obj_list, obj, next); 3056 obj_count++; 3057 obj_loads++; 3058 linkmap_add(obj); /* for GDB & dlinfo() */ 3059 max_stack_flags |= obj->stack_flags; 3060 3061 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 3062 obj->path); 3063 return (0); 3064 } 3065 3066 Obj_Entry * 3067 obj_from_addr(const void *addr) 3068 { 3069 Obj_Entry *obj; 3070 3071 TAILQ_FOREACH(obj, &obj_list, next) { 3072 if (obj->marker) 3073 continue; 3074 if (addr < (void *)obj->mapbase) 3075 continue; 3076 if (addr < (void *)(obj->mapbase + obj->mapsize)) 3077 return obj; 3078 } 3079 return (NULL); 3080 } 3081 3082 static void 3083 preinit_main(void) 3084 { 3085 uintptr_t *preinit_addr; 3086 int index; 3087 3088 preinit_addr = obj_main->preinit_array; 3089 if (preinit_addr == NULL) 3090 return; 3091 3092 for (index = 0; index < obj_main->preinit_array_num; index++) { 3093 if (preinit_addr[index] != 0 && preinit_addr[index] != 1) { 3094 dbg("calling preinit function for %s at %p", 3095 obj_main->path, (void *)preinit_addr[index]); 3096 LD_UTRACE(UTRACE_INIT_CALL, obj_main, 3097 (void *)preinit_addr[index], 0, 0, obj_main->path); 3098 call_init_pointer(obj_main, preinit_addr[index]); 3099 } 3100 } 3101 } 3102 3103 /* 3104 * Call the finalization functions for each of the objects in "list" 3105 * belonging to the DAG of "root" and referenced once. If NULL "root" 3106 * is specified, every finalization function will be called regardless 3107 * of the reference count and the list elements won't be freed. All of 3108 * the objects are expected to have non-NULL fini functions. 3109 */ 3110 static void 3111 objlist_call_fini(Objlist *list, Obj_Entry *root, RtldLockState *lockstate) 3112 { 3113 Objlist_Entry *elm; 3114 struct dlerror_save *saved_msg; 3115 uintptr_t *fini_addr; 3116 int index; 3117 3118 assert(root == NULL || root->refcount == 1); 3119 3120 if (root != NULL) 3121 root->doomed = true; 3122 3123 /* 3124 * Preserve the current error message since a fini function might 3125 * call into the dynamic linker and overwrite it. 3126 */ 3127 saved_msg = errmsg_save(); 3128 do { 3129 STAILQ_FOREACH(elm, list, link) { 3130 if (root != NULL && 3131 (elm->obj->refcount != 1 || 3132 objlist_find(&root->dagmembers, elm->obj) == 3133 NULL)) 3134 continue; 3135 /* Remove object from fini list to prevent recursive 3136 * invocation. */ 3137 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 3138 /* Ensure that new references cannot be acquired. */ 3139 elm->obj->doomed = true; 3140 3141 hold_object(elm->obj); 3142 lock_release(rtld_bind_lock, lockstate); 3143 /* 3144 * It is legal to have both DT_FINI and DT_FINI_ARRAY 3145 * defined. When this happens, DT_FINI_ARRAY is 3146 * processed first. 3147 */ 3148 fini_addr = elm->obj->fini_array; 3149 if (fini_addr != NULL && elm->obj->fini_array_num > 0) { 3150 for (index = elm->obj->fini_array_num - 1; 3151 index >= 0; index--) { 3152 if (fini_addr[index] != 0 && 3153 fini_addr[index] != 1) { 3154 dbg("calling fini function for %s at %p", 3155 elm->obj->path, 3156 (void *)fini_addr[index]); 3157 LD_UTRACE(UTRACE_FINI_CALL, 3158 elm->obj, 3159 (void *)fini_addr[index], 0, 3160 0, elm->obj->path); 3161 call_initfini_pointer(elm->obj, 3162 fini_addr[index]); 3163 } 3164 } 3165 } 3166 if (elm->obj->fini != 0) { 3167 dbg("calling fini function for %s at %p", 3168 elm->obj->path, (void *)elm->obj->fini); 3169 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, 3170 (void *)elm->obj->fini, 0, 0, 3171 elm->obj->path); 3172 call_initfini_pointer(elm->obj, elm->obj->fini); 3173 } 3174 wlock_acquire(rtld_bind_lock, lockstate); 3175 unhold_object(elm->obj); 3176 /* No need to free anything if process is going down. */ 3177 if (root != NULL) 3178 free(elm); 3179 /* 3180 * We must restart the list traversal after every fini 3181 * call because a dlclose() call from the fini function 3182 * or from another thread might have modified the 3183 * reference counts. 3184 */ 3185 break; 3186 } 3187 } while (elm != NULL); 3188 errmsg_restore(saved_msg); 3189 } 3190 3191 /* 3192 * Call the initialization functions for each of the objects in 3193 * "list". All of the objects are expected to have non-NULL init 3194 * functions. 3195 */ 3196 static void 3197 objlist_call_init(Objlist *list, RtldLockState *lockstate) 3198 { 3199 Objlist_Entry *elm; 3200 Obj_Entry *obj; 3201 struct dlerror_save *saved_msg; 3202 uintptr_t *init_addr; 3203 void (*reg)(void (*)(void)); 3204 int index; 3205 3206 /* 3207 * Clean init_scanned flag so that objects can be rechecked and 3208 * possibly initialized earlier if any of vectors called below 3209 * cause the change by using dlopen. 3210 */ 3211 TAILQ_FOREACH(obj, &obj_list, next) { 3212 if (obj->marker) 3213 continue; 3214 obj->init_scanned = false; 3215 } 3216 3217 /* 3218 * Preserve the current error message since an init function might 3219 * call into the dynamic linker and overwrite it. 3220 */ 3221 saved_msg = errmsg_save(); 3222 STAILQ_FOREACH(elm, list, link) { 3223 if (elm->obj->init_done) /* Initialized early. */ 3224 continue; 3225 /* 3226 * Race: other thread might try to use this object before 3227 * current one completes the initialization. Not much can be 3228 * done here without better locking. 3229 */ 3230 elm->obj->init_done = true; 3231 hold_object(elm->obj); 3232 reg = NULL; 3233 if (elm->obj == obj_main && obj_main->crt_no_init) { 3234 reg = (void (*)(void (*)(void))) 3235 get_program_var_addr("__libc_atexit", lockstate); 3236 } 3237 lock_release(rtld_bind_lock, lockstate); 3238 if (reg != NULL) { 3239 reg(rtld_exit); 3240 rtld_exit_ptr = rtld_nop_exit; 3241 } 3242 3243 /* 3244 * It is legal to have both DT_INIT and DT_INIT_ARRAY defined. 3245 * When this happens, DT_INIT is processed first. 3246 */ 3247 if (elm->obj->init != 0) { 3248 dbg("calling init function for %s at %p", 3249 elm->obj->path, (void *)elm->obj->init); 3250 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, 3251 (void *)elm->obj->init, 0, 0, elm->obj->path); 3252 call_init_pointer(elm->obj, elm->obj->init); 3253 } 3254 init_addr = elm->obj->init_array; 3255 if (init_addr != NULL) { 3256 for (index = 0; index < elm->obj->init_array_num; 3257 index++) { 3258 if (init_addr[index] != 0 && 3259 init_addr[index] != 1) { 3260 dbg("calling init function for %s at %p", 3261 elm->obj->path, 3262 (void *)init_addr[index]); 3263 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, 3264 (void *)init_addr[index], 0, 0, 3265 elm->obj->path); 3266 call_init_pointer(elm->obj, 3267 init_addr[index]); 3268 } 3269 } 3270 } 3271 wlock_acquire(rtld_bind_lock, lockstate); 3272 unhold_object(elm->obj); 3273 } 3274 errmsg_restore(saved_msg); 3275 } 3276 3277 static void 3278 objlist_clear(Objlist *list) 3279 { 3280 Objlist_Entry *elm; 3281 3282 while (!STAILQ_EMPTY(list)) { 3283 elm = STAILQ_FIRST(list); 3284 STAILQ_REMOVE_HEAD(list, link); 3285 free(elm); 3286 } 3287 } 3288 3289 static Objlist_Entry * 3290 objlist_find(Objlist *list, const Obj_Entry *obj) 3291 { 3292 Objlist_Entry *elm; 3293 3294 STAILQ_FOREACH(elm, list, link) 3295 if (elm->obj == obj) 3296 return elm; 3297 return (NULL); 3298 } 3299 3300 static void 3301 objlist_init(Objlist *list) 3302 { 3303 STAILQ_INIT(list); 3304 } 3305 3306 static void 3307 objlist_push_head(Objlist *list, Obj_Entry *obj) 3308 { 3309 Objlist_Entry *elm; 3310 3311 elm = NEW(Objlist_Entry); 3312 elm->obj = obj; 3313 STAILQ_INSERT_HEAD(list, elm, link); 3314 } 3315 3316 static void 3317 objlist_push_tail(Objlist *list, Obj_Entry *obj) 3318 { 3319 Objlist_Entry *elm; 3320 3321 elm = NEW(Objlist_Entry); 3322 elm->obj = obj; 3323 STAILQ_INSERT_TAIL(list, elm, link); 3324 } 3325 3326 static void 3327 objlist_put_after(Objlist *list, Obj_Entry *listobj, Obj_Entry *obj) 3328 { 3329 Objlist_Entry *elm, *listelm; 3330 3331 STAILQ_FOREACH(listelm, list, link) { 3332 if (listelm->obj == listobj) 3333 break; 3334 } 3335 elm = NEW(Objlist_Entry); 3336 elm->obj = obj; 3337 if (listelm != NULL) 3338 STAILQ_INSERT_AFTER(list, listelm, elm, link); 3339 else 3340 STAILQ_INSERT_TAIL(list, elm, link); 3341 } 3342 3343 static void 3344 objlist_remove(Objlist *list, Obj_Entry *obj) 3345 { 3346 Objlist_Entry *elm; 3347 3348 if ((elm = objlist_find(list, obj)) != NULL) { 3349 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 3350 free(elm); 3351 } 3352 } 3353 3354 /* 3355 * Relocate dag rooted in the specified object. 3356 * Returns 0 on success, or -1 on failure. 3357 */ 3358 3359 static int 3360 relocate_object_dag(Obj_Entry *root, bool bind_now, Obj_Entry *rtldobj, 3361 int flags, RtldLockState *lockstate) 3362 { 3363 Objlist_Entry *elm; 3364 int error; 3365 3366 error = 0; 3367 STAILQ_FOREACH(elm, &root->dagmembers, link) { 3368 error = relocate_object(elm->obj, bind_now, rtldobj, flags, 3369 lockstate); 3370 if (error == -1) 3371 break; 3372 } 3373 return (error); 3374 } 3375 3376 /* 3377 * Prepare for, or clean after, relocating an object marked with 3378 * DT_TEXTREL or DF_TEXTREL. Before relocating, all read-only 3379 * segments are remapped read-write. After relocations are done, the 3380 * segment's permissions are returned back to the modes specified in 3381 * the phdrs. If any relocation happened, or always for wired 3382 * program, COW is triggered. 3383 */ 3384 static int 3385 reloc_textrel_prot(Obj_Entry *obj, bool before) 3386 { 3387 const Elf_Phdr *ph; 3388 void *base; 3389 size_t sz; 3390 int prot; 3391 3392 for (ph = obj->phdr; ph < obj->phdr + obj->phnum; ph++) { 3393 if (ph->p_type != PT_LOAD || (ph->p_flags & PF_W) != 0) 3394 continue; 3395 base = obj->relocbase + rtld_trunc_page(ph->p_vaddr); 3396 sz = rtld_round_page(ph->p_vaddr + ph->p_filesz) - 3397 rtld_trunc_page(ph->p_vaddr); 3398 prot = before ? (PROT_READ | PROT_WRITE) : 3399 convert_prot(ph->p_flags); 3400 if (mprotect(base, sz, prot) == -1) { 3401 _rtld_error("%s: Cannot write-%sable text segment: %s", 3402 obj->path, before ? "en" : "dis", 3403 rtld_strerror(errno)); 3404 return (-1); 3405 } 3406 } 3407 return (0); 3408 } 3409 3410 /* Process RELR relative relocations. */ 3411 static void 3412 reloc_relr(Obj_Entry *obj) 3413 { 3414 const Elf_Relr *relr, *relrlim; 3415 Elf_Addr *where; 3416 3417 relrlim = (const Elf_Relr *)((const char *)obj->relr + obj->relrsize); 3418 for (relr = obj->relr; relr < relrlim; relr++) { 3419 Elf_Relr entry = *relr; 3420 3421 if ((entry & 1) == 0) { 3422 where = (Elf_Addr *)(obj->relocbase + entry); 3423 *where++ += (Elf_Addr)obj->relocbase; 3424 } else { 3425 for (long i = 0; (entry >>= 1) != 0; i++) 3426 if ((entry & 1) != 0) 3427 where[i] += (Elf_Addr)obj->relocbase; 3428 where += CHAR_BIT * sizeof(Elf_Relr) - 1; 3429 } 3430 } 3431 } 3432 3433 /* 3434 * Relocate single object. 3435 * Returns 0 on success, or -1 on failure. 3436 */ 3437 static int 3438 relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, int flags, 3439 RtldLockState *lockstate) 3440 { 3441 if (obj->relocated) 3442 return (0); 3443 obj->relocated = true; 3444 if (obj != rtldobj) 3445 dbg("relocating \"%s\"", obj->path); 3446 3447 if (obj->symtab == NULL || obj->strtab == NULL || 3448 !(obj->valid_hash_sysv || obj->valid_hash_gnu)) 3449 dbg("object %s has no run-time symbol table", obj->path); 3450 3451 /* There are relocations to the write-protected text segment. */ 3452 if (obj->textrel && reloc_textrel_prot(obj, true) != 0) 3453 return (-1); 3454 3455 /* Process the non-PLT non-IFUNC relocations. */ 3456 if (reloc_non_plt(obj, rtldobj, flags, lockstate)) 3457 return (-1); 3458 reloc_relr(obj); 3459 3460 /* Re-protected the text segment. */ 3461 if (obj->textrel && reloc_textrel_prot(obj, false) != 0) 3462 return (-1); 3463 3464 /* Set the special PLT or GOT entries. */ 3465 init_pltgot(obj); 3466 3467 /* Process the PLT relocations. */ 3468 if (reloc_plt(obj, flags, lockstate) == -1) 3469 return (-1); 3470 /* Relocate the jump slots if we are doing immediate binding. */ 3471 if ((obj->bind_now || bind_now) && 3472 reloc_jmpslots(obj, flags, lockstate) == -1) 3473 return (-1); 3474 3475 if (obj != rtldobj && !obj->mainprog && obj_enforce_relro(obj) == -1) 3476 return (-1); 3477 3478 /* 3479 * Set up the magic number and version in the Obj_Entry. These 3480 * were checked in the crt1.o from the original ElfKit, so we 3481 * set them for backward compatibility. 3482 */ 3483 obj->magic = RTLD_MAGIC; 3484 obj->version = RTLD_VERSION; 3485 3486 return (0); 3487 } 3488 3489 /* 3490 * Relocate newly-loaded shared objects. The argument is a pointer to 3491 * the Obj_Entry for the first such object. All objects from the first 3492 * to the end of the list of objects are relocated. Returns 0 on success, 3493 * or -1 on failure. 3494 */ 3495 static int 3496 relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj, int flags, 3497 RtldLockState *lockstate) 3498 { 3499 Obj_Entry *obj; 3500 int error; 3501 3502 for (error = 0, obj = first; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 3503 if (obj->marker) 3504 continue; 3505 error = relocate_object(obj, bind_now, rtldobj, flags, 3506 lockstate); 3507 if (error == -1) 3508 break; 3509 } 3510 return (error); 3511 } 3512 3513 /* 3514 * The handling of R_MACHINE_IRELATIVE relocations and jumpslots 3515 * referencing STT_GNU_IFUNC symbols is postponed till the other 3516 * relocations are done. The indirect functions specified as 3517 * ifunc are allowed to call other symbols, so we need to have 3518 * objects relocated before asking for resolution from indirects. 3519 * 3520 * The R_MACHINE_IRELATIVE slots are resolved in greedy fashion, 3521 * instead of the usual lazy handling of PLT slots. It is 3522 * consistent with how GNU does it. 3523 */ 3524 static int 3525 resolve_object_ifunc(Obj_Entry *obj, bool bind_now, int flags, 3526 RtldLockState *lockstate) 3527 { 3528 if (obj->ifuncs_resolved) 3529 return (0); 3530 obj->ifuncs_resolved = true; 3531 if (!obj->irelative && !obj->irelative_nonplt && 3532 !((obj->bind_now || bind_now) && obj->gnu_ifunc) && 3533 !obj->non_plt_gnu_ifunc) 3534 return (0); 3535 if (obj_disable_relro(obj) == -1 || 3536 (obj->irelative && reloc_iresolve(obj, lockstate) == -1) || 3537 (obj->irelative_nonplt && 3538 reloc_iresolve_nonplt(obj, lockstate) == -1) || 3539 ((obj->bind_now || bind_now) && obj->gnu_ifunc && 3540 reloc_gnu_ifunc(obj, flags, lockstate) == -1) || 3541 (obj->non_plt_gnu_ifunc && 3542 reloc_non_plt(obj, &obj_rtld, flags | SYMLOOK_IFUNC, 3543 lockstate) == -1) || 3544 obj_enforce_relro(obj) == -1) 3545 return (-1); 3546 return (0); 3547 } 3548 3549 static int 3550 initlist_objects_ifunc(Objlist *list, bool bind_now, int flags, 3551 RtldLockState *lockstate) 3552 { 3553 Objlist_Entry *elm; 3554 Obj_Entry *obj; 3555 3556 STAILQ_FOREACH(elm, list, link) { 3557 obj = elm->obj; 3558 if (obj->marker) 3559 continue; 3560 if (resolve_object_ifunc(obj, bind_now, flags, lockstate) == -1) 3561 return (-1); 3562 } 3563 return (0); 3564 } 3565 3566 /* 3567 * Cleanup procedure. It will be called (by the atexit mechanism) just 3568 * before the process exits. 3569 */ 3570 static void 3571 rtld_exit(void) 3572 { 3573 RtldLockState lockstate; 3574 3575 wlock_acquire(rtld_bind_lock, &lockstate); 3576 dbg("rtld_exit()"); 3577 objlist_call_fini(&list_fini, NULL, &lockstate); 3578 /* No need to remove the items from the list, since we are exiting. */ 3579 if (!libmap_disable) 3580 lm_fini(); 3581 lock_release(rtld_bind_lock, &lockstate); 3582 } 3583 3584 static void 3585 rtld_nop_exit(void) 3586 { 3587 } 3588 3589 /* 3590 * Iterate over a search path, translate each element, and invoke the 3591 * callback on the result. 3592 */ 3593 static void * 3594 path_enumerate(const char *path, path_enum_proc callback, 3595 const char *refobj_path, void *arg) 3596 { 3597 const char *trans; 3598 if (path == NULL) 3599 return (NULL); 3600 3601 path += strspn(path, ":;"); 3602 while (*path != '\0') { 3603 size_t len; 3604 char *res; 3605 3606 len = strcspn(path, ":;"); 3607 trans = lm_findn(refobj_path, path, len); 3608 if (trans) 3609 res = callback(trans, strlen(trans), arg); 3610 else 3611 res = callback(path, len, arg); 3612 3613 if (res != NULL) 3614 return (res); 3615 3616 path += len; 3617 path += strspn(path, ":;"); 3618 } 3619 3620 return (NULL); 3621 } 3622 3623 struct try_library_args { 3624 const char *name; 3625 size_t namelen; 3626 char *buffer; 3627 size_t buflen; 3628 int fd; 3629 }; 3630 3631 static void * 3632 try_library_path(const char *dir, size_t dirlen, void *param) 3633 { 3634 struct try_library_args *arg; 3635 int fd; 3636 3637 arg = param; 3638 if (*dir == '/' || trust) { 3639 char *pathname; 3640 3641 if (dirlen + 1 + arg->namelen + 1 > arg->buflen) 3642 return (NULL); 3643 3644 pathname = arg->buffer; 3645 strncpy(pathname, dir, dirlen); 3646 pathname[dirlen] = '/'; 3647 strcpy(pathname + dirlen + 1, arg->name); 3648 3649 dbg(" Trying \"%s\"", pathname); 3650 fd = open(pathname, O_RDONLY | O_CLOEXEC | O_VERIFY); 3651 if (fd >= 0) { 3652 dbg(" Opened \"%s\", fd %d", pathname, fd); 3653 pathname = xmalloc(dirlen + 1 + arg->namelen + 1); 3654 strcpy(pathname, arg->buffer); 3655 arg->fd = fd; 3656 return (pathname); 3657 } else { 3658 dbg(" Failed to open \"%s\": %s", pathname, 3659 rtld_strerror(errno)); 3660 } 3661 } 3662 return (NULL); 3663 } 3664 3665 static char * 3666 search_library_path(const char *name, const char *path, const char *refobj_path, 3667 int *fdp) 3668 { 3669 char *p; 3670 struct try_library_args arg; 3671 3672 if (path == NULL) 3673 return (NULL); 3674 3675 arg.name = name; 3676 arg.namelen = strlen(name); 3677 arg.buffer = xmalloc(PATH_MAX); 3678 arg.buflen = PATH_MAX; 3679 arg.fd = -1; 3680 3681 p = path_enumerate(path, try_library_path, refobj_path, &arg); 3682 *fdp = arg.fd; 3683 3684 free(arg.buffer); 3685 3686 return (p); 3687 } 3688 3689 /* 3690 * Finds the library with the given name using the directory descriptors 3691 * listed in the LD_LIBRARY_PATH_FDS environment variable. 3692 * 3693 * Returns a freshly-opened close-on-exec file descriptor for the library, 3694 * or -1 if the library cannot be found. 3695 */ 3696 static char * 3697 search_library_pathfds(const char *name, const char *path, int *fdp) 3698 { 3699 char *envcopy, *fdstr, *found, *last_token; 3700 size_t len; 3701 int dirfd, fd; 3702 3703 dbg("%s('%s', '%s', fdp)", __func__, name, path); 3704 3705 /* Don't load from user-specified libdirs into setuid binaries. */ 3706 if (!trust) 3707 return (NULL); 3708 3709 /* We can't do anything if LD_LIBRARY_PATH_FDS isn't set. */ 3710 if (path == NULL) 3711 return (NULL); 3712 3713 /* LD_LIBRARY_PATH_FDS only works with relative paths. */ 3714 if (name[0] == '/') { 3715 dbg("Absolute path (%s) passed to %s", name, __func__); 3716 return (NULL); 3717 } 3718 3719 /* 3720 * Use strtok_r() to walk the FD:FD:FD list. This requires a local 3721 * copy of the path, as strtok_r rewrites separator tokens 3722 * with '\0'. 3723 */ 3724 found = NULL; 3725 envcopy = xstrdup(path); 3726 for (fdstr = strtok_r(envcopy, ":", &last_token); fdstr != NULL; 3727 fdstr = strtok_r(NULL, ":", &last_token)) { 3728 dirfd = parse_integer(fdstr); 3729 if (dirfd < 0) { 3730 _rtld_error("failed to parse directory FD: '%s'", 3731 fdstr); 3732 break; 3733 } 3734 fd = __sys_openat(dirfd, name, O_RDONLY | O_CLOEXEC | O_VERIFY); 3735 if (fd >= 0) { 3736 *fdp = fd; 3737 len = strlen(fdstr) + strlen(name) + 3; 3738 found = xmalloc(len); 3739 if (rtld_snprintf(found, len, "#%d/%s", dirfd, name) < 3740 0) { 3741 _rtld_error("error generating '%d/%s'", dirfd, 3742 name); 3743 rtld_die(); 3744 } 3745 dbg("open('%s') => %d", found, fd); 3746 break; 3747 } 3748 } 3749 free(envcopy); 3750 3751 return (found); 3752 } 3753 3754 int 3755 dlclose(void *handle) 3756 { 3757 RtldLockState lockstate; 3758 int error; 3759 3760 wlock_acquire(rtld_bind_lock, &lockstate); 3761 error = dlclose_locked(handle, &lockstate); 3762 lock_release(rtld_bind_lock, &lockstate); 3763 return (error); 3764 } 3765 3766 static int 3767 dlclose_locked(void *handle, RtldLockState *lockstate) 3768 { 3769 Obj_Entry *root; 3770 3771 root = dlcheck(handle); 3772 if (root == NULL) 3773 return (-1); 3774 LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount, 3775 root->path); 3776 3777 /* Unreference the object and its dependencies. */ 3778 root->dl_refcount--; 3779 3780 if (root->refcount == 1) { 3781 /* 3782 * The object will be no longer referenced, so we must unload 3783 * it. First, call the fini functions. 3784 */ 3785 objlist_call_fini(&list_fini, root, lockstate); 3786 3787 unref_dag(root); 3788 3789 /* Finish cleaning up the newly-unreferenced objects. */ 3790 GDB_STATE(RT_DELETE, &root->linkmap); 3791 unload_object(root, lockstate); 3792 GDB_STATE(RT_CONSISTENT, NULL); 3793 } else 3794 unref_dag(root); 3795 3796 LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL); 3797 return (0); 3798 } 3799 3800 char * 3801 dlerror(void) 3802 { 3803 if (*(lockinfo.dlerror_seen()) != 0) 3804 return (NULL); 3805 *lockinfo.dlerror_seen() = 1; 3806 return (lockinfo.dlerror_loc()); 3807 } 3808 3809 /* 3810 * This function is deprecated and has no effect. 3811 */ 3812 void 3813 dllockinit(void *context, void *(*_lock_create)(void *context)__unused, 3814 void (*_rlock_acquire)(void *lock) __unused, 3815 void (*_wlock_acquire)(void *lock) __unused, 3816 void (*_lock_release)(void *lock) __unused, 3817 void (*_lock_destroy)(void *lock) __unused, 3818 void (*context_destroy)(void *context)) 3819 { 3820 static void *cur_context; 3821 static void (*cur_context_destroy)(void *); 3822 3823 /* Just destroy the context from the previous call, if necessary. */ 3824 if (cur_context_destroy != NULL) 3825 cur_context_destroy(cur_context); 3826 cur_context = context; 3827 cur_context_destroy = context_destroy; 3828 } 3829 3830 void * 3831 dlopen(const char *name, int mode) 3832 { 3833 return (rtld_dlopen(name, -1, mode)); 3834 } 3835 3836 void * 3837 fdlopen(int fd, int mode) 3838 { 3839 return (rtld_dlopen(NULL, fd, mode)); 3840 } 3841 3842 static void * 3843 rtld_dlopen(const char *name, int fd, int mode) 3844 { 3845 RtldLockState lockstate; 3846 int lo_flags; 3847 3848 LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name); 3849 ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1"; 3850 if (ld_tracing != NULL) { 3851 rlock_acquire(rtld_bind_lock, &lockstate); 3852 if (sigsetjmp(lockstate.env, 0) != 0) 3853 lock_upgrade(rtld_bind_lock, &lockstate); 3854 environ = __DECONST(char **, 3855 *get_program_var_addr("environ", &lockstate)); 3856 lock_release(rtld_bind_lock, &lockstate); 3857 } 3858 lo_flags = RTLD_LO_DLOPEN; 3859 if (mode & RTLD_NODELETE) 3860 lo_flags |= RTLD_LO_NODELETE; 3861 if (mode & RTLD_NOLOAD) 3862 lo_flags |= RTLD_LO_NOLOAD; 3863 if (mode & RTLD_DEEPBIND) 3864 lo_flags |= RTLD_LO_DEEPBIND; 3865 if (ld_tracing != NULL) 3866 lo_flags |= RTLD_LO_TRACE | RTLD_LO_IGNSTLS; 3867 3868 return (dlopen_object(name, fd, obj_main, lo_flags, 3869 mode & (RTLD_MODEMASK | RTLD_GLOBAL), NULL)); 3870 } 3871 3872 static void 3873 dlopen_cleanup(Obj_Entry *obj, RtldLockState *lockstate) 3874 { 3875 obj->dl_refcount--; 3876 unref_dag(obj); 3877 if (obj->refcount == 0) 3878 unload_object(obj, lockstate); 3879 } 3880 3881 static Obj_Entry * 3882 dlopen_object(const char *name, int fd, Obj_Entry *refobj, int lo_flags, 3883 int mode, RtldLockState *lockstate) 3884 { 3885 Obj_Entry *obj; 3886 Objlist initlist; 3887 RtldLockState mlockstate; 3888 int result; 3889 3890 dbg( 3891 "dlopen_object name \"%s\" fd %d refobj \"%s\" lo_flags %#x mode %#x", 3892 name != NULL ? name : "<null>", fd, 3893 refobj == NULL ? "<null>" : refobj->path, lo_flags, mode); 3894 objlist_init(&initlist); 3895 3896 if (lockstate == NULL && !(lo_flags & RTLD_LO_EARLY)) { 3897 wlock_acquire(rtld_bind_lock, &mlockstate); 3898 lockstate = &mlockstate; 3899 } 3900 GDB_STATE(RT_ADD, NULL); 3901 3902 obj = NULL; 3903 if (name == NULL && fd == -1) { 3904 obj = obj_main; 3905 obj->refcount++; 3906 } else { 3907 obj = load_object(name, fd, refobj, lo_flags); 3908 } 3909 3910 if (obj != NULL) { 3911 obj->dl_refcount++; 3912 if ((mode & RTLD_GLOBAL) != 0 && 3913 objlist_find(&list_global, obj) == NULL) 3914 objlist_push_tail(&list_global, obj); 3915 3916 if (!obj->init_done) { 3917 /* We loaded something new and have to init something. 3918 */ 3919 if ((lo_flags & RTLD_LO_DEEPBIND) != 0) 3920 obj->deepbind = true; 3921 result = 0; 3922 if ((lo_flags & (RTLD_LO_EARLY | 3923 RTLD_LO_IGNSTLS)) == 0 && 3924 obj->static_tls && !allocate_tls_offset(obj)) { 3925 _rtld_error( 3926 "%s: No space available for static Thread Local Storage", 3927 obj->path); 3928 result = -1; 3929 } 3930 if (result != -1) 3931 result = load_needed_objects(obj, 3932 lo_flags & (RTLD_LO_DLOPEN | RTLD_LO_EARLY | 3933 RTLD_LO_IGNSTLS | RTLD_LO_TRACE)); 3934 init_dag(obj); 3935 ref_dag(obj); 3936 if (result != -1) 3937 result = rtld_verify_versions(&obj->dagmembers); 3938 if (result != -1 && ld_tracing) 3939 goto trace; 3940 if (result == -1 || relocate_object_dag(obj, 3941 (mode & RTLD_MODEMASK) == RTLD_NOW, &obj_rtld, 3942 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 3943 lockstate) == -1) { 3944 dlopen_cleanup(obj, lockstate); 3945 obj = NULL; 3946 } else if ((lo_flags & RTLD_LO_EARLY) != 0) { 3947 /* 3948 * Do not call the init functions for early 3949 * loaded filtees. The image is still not 3950 * initialized enough for them to work. 3951 * 3952 * Our object is found by the global object list 3953 * and will be ordered among all init calls done 3954 * right before transferring control to main. 3955 */ 3956 } else { 3957 /* Make list of init functions to call. */ 3958 initlist_for_loaded_obj(obj, obj, &initlist); 3959 } 3960 /* 3961 * Process all no_delete or global objects here, given 3962 * them own DAGs to prevent their dependencies from 3963 * being unloaded. This has to be done after we have 3964 * loaded all of the dependencies, so that we do not 3965 * miss any. 3966 */ 3967 if (obj != NULL) 3968 process_z(obj); 3969 } else { 3970 /* 3971 * Bump the reference counts for objects on this DAG. If 3972 * this is the first dlopen() call for the object that 3973 * was already loaded as a dependency, initialize the 3974 * dag starting at it. 3975 */ 3976 init_dag(obj); 3977 ref_dag(obj); 3978 3979 if ((lo_flags & RTLD_LO_TRACE) != 0) 3980 goto trace; 3981 } 3982 if (obj != NULL && 3983 ((lo_flags & RTLD_LO_NODELETE) != 0 || obj->z_nodelete) && 3984 !obj->ref_nodel) { 3985 dbg("obj %s nodelete", obj->path); 3986 ref_dag(obj); 3987 obj->z_nodelete = obj->ref_nodel = true; 3988 } 3989 } 3990 3991 LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0, 3992 name); 3993 GDB_STATE(RT_CONSISTENT, obj ? &obj->linkmap : NULL); 3994 3995 if ((lo_flags & RTLD_LO_EARLY) == 0) { 3996 map_stacks_exec(lockstate); 3997 if (obj != NULL) 3998 distribute_static_tls(&initlist); 3999 } 4000 4001 if (initlist_objects_ifunc(&initlist, (mode & RTLD_MODEMASK) == 4002 RTLD_NOW, (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 4003 lockstate) == -1) { 4004 objlist_clear(&initlist); 4005 dlopen_cleanup(obj, lockstate); 4006 if (lockstate == &mlockstate) 4007 lock_release(rtld_bind_lock, lockstate); 4008 return (NULL); 4009 } 4010 4011 if ((lo_flags & RTLD_LO_EARLY) == 0) { 4012 /* Call the init functions. */ 4013 objlist_call_init(&initlist, lockstate); 4014 } 4015 objlist_clear(&initlist); 4016 if (lockstate == &mlockstate) 4017 lock_release(rtld_bind_lock, lockstate); 4018 return (obj); 4019 trace: 4020 trace_loaded_objects(obj, false); 4021 if (lockstate == &mlockstate) 4022 lock_release(rtld_bind_lock, lockstate); 4023 exit(0); 4024 } 4025 4026 static void * 4027 do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve, 4028 int flags) 4029 { 4030 DoneList donelist; 4031 const Obj_Entry *obj, *defobj; 4032 const Elf_Sym *def; 4033 SymLook req; 4034 RtldLockState lockstate; 4035 tls_index ti; 4036 void *sym; 4037 int res; 4038 4039 def = NULL; 4040 defobj = NULL; 4041 symlook_init(&req, name); 4042 req.ventry = ve; 4043 req.flags = flags | SYMLOOK_IN_PLT; 4044 req.lockstate = &lockstate; 4045 4046 LD_UTRACE(UTRACE_DLSYM_START, handle, NULL, 0, 0, name); 4047 rlock_acquire(rtld_bind_lock, &lockstate); 4048 if (sigsetjmp(lockstate.env, 0) != 0) 4049 lock_upgrade(rtld_bind_lock, &lockstate); 4050 if (handle == NULL || handle == RTLD_NEXT || handle == RTLD_DEFAULT || 4051 handle == RTLD_SELF) { 4052 if ((obj = obj_from_addr(retaddr)) == NULL) { 4053 _rtld_error("Cannot determine caller's shared object"); 4054 lock_release(rtld_bind_lock, &lockstate); 4055 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 4056 return (NULL); 4057 } 4058 if (handle == NULL) { /* Just the caller's shared object. */ 4059 res = symlook_obj(&req, obj); 4060 if (res == 0) { 4061 def = req.sym_out; 4062 defobj = req.defobj_out; 4063 } 4064 } else if (handle == RTLD_NEXT || /* Objects after caller's */ 4065 handle == RTLD_SELF) { /* ... caller included */ 4066 if (handle == RTLD_NEXT) 4067 obj = globallist_next(obj); 4068 for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 4069 if (obj->marker) 4070 continue; 4071 res = symlook_obj(&req, obj); 4072 if (res == 0) { 4073 if (def == NULL || 4074 (ld_dynamic_weak && 4075 ELF_ST_BIND( 4076 req.sym_out->st_info) != 4077 STB_WEAK)) { 4078 def = req.sym_out; 4079 defobj = req.defobj_out; 4080 if (!ld_dynamic_weak || 4081 ELF_ST_BIND(def->st_info) != 4082 STB_WEAK) 4083 break; 4084 } 4085 } 4086 } 4087 /* 4088 * Search the dynamic linker itself, and possibly 4089 * resolve the symbol from there. This is how the 4090 * application links to dynamic linker services such as 4091 * dlopen. Note that we ignore ld_dynamic_weak == false 4092 * case, always overriding weak symbols by rtld 4093 * definitions. 4094 */ 4095 if (def == NULL || 4096 ELF_ST_BIND(def->st_info) == STB_WEAK) { 4097 res = symlook_obj(&req, &obj_rtld); 4098 if (res == 0) { 4099 def = req.sym_out; 4100 defobj = req.defobj_out; 4101 } 4102 } 4103 } else { 4104 assert(handle == RTLD_DEFAULT); 4105 res = symlook_default(&req, obj); 4106 if (res == 0) { 4107 defobj = req.defobj_out; 4108 def = req.sym_out; 4109 } 4110 } 4111 } else { 4112 if ((obj = dlcheck(handle)) == NULL) { 4113 lock_release(rtld_bind_lock, &lockstate); 4114 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 4115 return (NULL); 4116 } 4117 4118 donelist_init(&donelist); 4119 if (obj->mainprog) { 4120 /* Handle obtained by dlopen(NULL, ...) implies global 4121 * scope. */ 4122 res = symlook_global(&req, &donelist); 4123 if (res == 0) { 4124 def = req.sym_out; 4125 defobj = req.defobj_out; 4126 } 4127 /* 4128 * Search the dynamic linker itself, and possibly 4129 * resolve the symbol from there. This is how the 4130 * application links to dynamic linker services such as 4131 * dlopen. 4132 */ 4133 if (def == NULL || 4134 ELF_ST_BIND(def->st_info) == STB_WEAK) { 4135 res = symlook_obj(&req, &obj_rtld); 4136 if (res == 0) { 4137 def = req.sym_out; 4138 defobj = req.defobj_out; 4139 } 4140 } 4141 } else { 4142 /* Search the whole DAG rooted at the given object. */ 4143 res = symlook_list(&req, &obj->dagmembers, &donelist); 4144 if (res == 0) { 4145 def = req.sym_out; 4146 defobj = req.defobj_out; 4147 } 4148 } 4149 } 4150 4151 if (def != NULL) { 4152 lock_release(rtld_bind_lock, &lockstate); 4153 4154 /* 4155 * The value required by the caller is derived from the value 4156 * of the symbol. this is simply the relocated value of the 4157 * symbol. 4158 */ 4159 if (ELF_ST_TYPE(def->st_info) == STT_FUNC) 4160 sym = make_function_pointer(def, defobj); 4161 else if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 4162 sym = rtld_resolve_ifunc(defobj, def); 4163 else if (ELF_ST_TYPE(def->st_info) == STT_TLS) { 4164 ti.ti_module = defobj->tlsindex; 4165 ti.ti_offset = def->st_value - TLS_DTV_OFFSET; 4166 sym = __tls_get_addr(&ti); 4167 } else 4168 sym = defobj->relocbase + def->st_value; 4169 LD_UTRACE(UTRACE_DLSYM_STOP, handle, sym, 0, 0, name); 4170 return (sym); 4171 } 4172 4173 _rtld_error("Undefined symbol \"%s%s%s\"", name, ve != NULL ? "@" : "", 4174 ve != NULL ? ve->name : ""); 4175 lock_release(rtld_bind_lock, &lockstate); 4176 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 4177 return (NULL); 4178 } 4179 4180 void * 4181 dlsym(void *handle, const char *name) 4182 { 4183 return (do_dlsym(handle, name, __builtin_return_address(0), NULL, 4184 SYMLOOK_DLSYM)); 4185 } 4186 4187 dlfunc_t 4188 dlfunc(void *handle, const char *name) 4189 { 4190 union { 4191 void *d; 4192 dlfunc_t f; 4193 } rv; 4194 4195 rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL, 4196 SYMLOOK_DLSYM); 4197 return (rv.f); 4198 } 4199 4200 void * 4201 dlvsym(void *handle, const char *name, const char *version) 4202 { 4203 Ver_Entry ventry; 4204 4205 ventry.name = version; 4206 ventry.file = NULL; 4207 ventry.hash = elf_hash(version); 4208 ventry.flags = 0; 4209 return (do_dlsym(handle, name, __builtin_return_address(0), &ventry, 4210 SYMLOOK_DLSYM)); 4211 } 4212 4213 int 4214 _rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info) 4215 { 4216 const Obj_Entry *obj; 4217 RtldLockState lockstate; 4218 4219 rlock_acquire(rtld_bind_lock, &lockstate); 4220 obj = obj_from_addr(addr); 4221 if (obj == NULL) { 4222 _rtld_error("No shared object contains address"); 4223 lock_release(rtld_bind_lock, &lockstate); 4224 return (0); 4225 } 4226 rtld_fill_dl_phdr_info(obj, phdr_info); 4227 lock_release(rtld_bind_lock, &lockstate); 4228 return (1); 4229 } 4230 4231 int 4232 dladdr(const void *addr, Dl_info *info) 4233 { 4234 const Obj_Entry *obj; 4235 const Elf_Sym *def; 4236 void *symbol_addr; 4237 unsigned long symoffset; 4238 RtldLockState lockstate; 4239 4240 rlock_acquire(rtld_bind_lock, &lockstate); 4241 obj = obj_from_addr(addr); 4242 if (obj == NULL) { 4243 _rtld_error("No shared object contains address"); 4244 lock_release(rtld_bind_lock, &lockstate); 4245 return (0); 4246 } 4247 info->dli_fname = obj->path; 4248 info->dli_fbase = obj->mapbase; 4249 info->dli_saddr = (void *)0; 4250 info->dli_sname = NULL; 4251 4252 /* 4253 * Walk the symbol list looking for the symbol whose address is 4254 * closest to the address sent in. 4255 */ 4256 for (symoffset = 0; symoffset < obj->dynsymcount; symoffset++) { 4257 def = obj->symtab + symoffset; 4258 4259 /* 4260 * For skip the symbol if st_shndx is either SHN_UNDEF or 4261 * SHN_COMMON. 4262 */ 4263 if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON) 4264 continue; 4265 4266 /* 4267 * If the symbol is greater than the specified address, or if it 4268 * is further away from addr than the current nearest symbol, 4269 * then reject it. 4270 */ 4271 symbol_addr = obj->relocbase + def->st_value; 4272 if (symbol_addr > addr || symbol_addr < info->dli_saddr) 4273 continue; 4274 4275 /* Update our idea of the nearest symbol. */ 4276 info->dli_sname = obj->strtab + def->st_name; 4277 info->dli_saddr = symbol_addr; 4278 4279 /* Exact match? */ 4280 if (info->dli_saddr == addr) 4281 break; 4282 } 4283 lock_release(rtld_bind_lock, &lockstate); 4284 return (1); 4285 } 4286 4287 int 4288 dlinfo(void *handle, int request, void *p) 4289 { 4290 const Obj_Entry *obj; 4291 RtldLockState lockstate; 4292 int error; 4293 4294 rlock_acquire(rtld_bind_lock, &lockstate); 4295 4296 if (handle == NULL || handle == RTLD_SELF) { 4297 void *retaddr; 4298 4299 retaddr = __builtin_return_address(0); /* __GNUC__ only */ 4300 if ((obj = obj_from_addr(retaddr)) == NULL) 4301 _rtld_error("Cannot determine caller's shared object"); 4302 } else 4303 obj = dlcheck(handle); 4304 4305 if (obj == NULL) { 4306 lock_release(rtld_bind_lock, &lockstate); 4307 return (-1); 4308 } 4309 4310 error = 0; 4311 switch (request) { 4312 case RTLD_DI_LINKMAP: 4313 *((struct link_map const **)p) = &obj->linkmap; 4314 break; 4315 case RTLD_DI_ORIGIN: 4316 error = rtld_dirname(obj->path, p); 4317 break; 4318 4319 case RTLD_DI_SERINFOSIZE: 4320 case RTLD_DI_SERINFO: 4321 error = do_search_info(obj, request, (struct dl_serinfo *)p); 4322 break; 4323 4324 default: 4325 _rtld_error("Invalid request %d passed to dlinfo()", request); 4326 error = -1; 4327 } 4328 4329 lock_release(rtld_bind_lock, &lockstate); 4330 4331 return (error); 4332 } 4333 4334 static void 4335 rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info) 4336 { 4337 phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase; 4338 phdr_info->dlpi_name = obj->path; 4339 phdr_info->dlpi_phdr = obj->phdr; 4340 phdr_info->dlpi_phnum = obj->phnum; 4341 phdr_info->dlpi_tls_modid = obj->tlsindex; 4342 phdr_info->dlpi_tls_data = (char *)tls_get_addr_slow(_tcb_get(), 4343 obj->tlsindex, 0, true); 4344 phdr_info->dlpi_adds = obj_loads; 4345 phdr_info->dlpi_subs = obj_loads - obj_count; 4346 } 4347 4348 /* 4349 * It's completely UB to actually use this, so extreme caution is advised. It's 4350 * probably not what you want. 4351 */ 4352 int 4353 _dl_iterate_phdr_locked(__dl_iterate_hdr_callback callback, void *param) 4354 { 4355 struct dl_phdr_info phdr_info; 4356 Obj_Entry *obj; 4357 int error; 4358 4359 for (obj = globallist_curr(TAILQ_FIRST(&obj_list)); obj != NULL; 4360 obj = globallist_next(obj)) { 4361 rtld_fill_dl_phdr_info(obj, &phdr_info); 4362 error = callback(&phdr_info, sizeof(phdr_info), param); 4363 if (error != 0) 4364 return (error); 4365 } 4366 4367 rtld_fill_dl_phdr_info(&obj_rtld, &phdr_info); 4368 return (callback(&phdr_info, sizeof(phdr_info), param)); 4369 } 4370 4371 int 4372 dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param) 4373 { 4374 struct dl_phdr_info phdr_info; 4375 Obj_Entry *obj, marker; 4376 RtldLockState bind_lockstate, phdr_lockstate; 4377 int error; 4378 4379 init_marker(&marker); 4380 error = 0; 4381 4382 wlock_acquire(rtld_phdr_lock, &phdr_lockstate); 4383 wlock_acquire(rtld_bind_lock, &bind_lockstate); 4384 for (obj = globallist_curr(TAILQ_FIRST(&obj_list)); obj != NULL;) { 4385 TAILQ_INSERT_AFTER(&obj_list, obj, &marker, next); 4386 rtld_fill_dl_phdr_info(obj, &phdr_info); 4387 hold_object(obj); 4388 lock_release(rtld_bind_lock, &bind_lockstate); 4389 4390 error = callback(&phdr_info, sizeof phdr_info, param); 4391 4392 wlock_acquire(rtld_bind_lock, &bind_lockstate); 4393 unhold_object(obj); 4394 obj = globallist_next(&marker); 4395 TAILQ_REMOVE(&obj_list, &marker, next); 4396 if (error != 0) { 4397 lock_release(rtld_bind_lock, &bind_lockstate); 4398 lock_release(rtld_phdr_lock, &phdr_lockstate); 4399 return (error); 4400 } 4401 } 4402 4403 if (error == 0) { 4404 rtld_fill_dl_phdr_info(&obj_rtld, &phdr_info); 4405 lock_release(rtld_bind_lock, &bind_lockstate); 4406 error = callback(&phdr_info, sizeof(phdr_info), param); 4407 } 4408 lock_release(rtld_phdr_lock, &phdr_lockstate); 4409 return (error); 4410 } 4411 4412 static void * 4413 fill_search_info(const char *dir, size_t dirlen, void *param) 4414 { 4415 struct fill_search_info_args *arg; 4416 4417 arg = param; 4418 4419 if (arg->request == RTLD_DI_SERINFOSIZE) { 4420 arg->serinfo->dls_cnt++; 4421 arg->serinfo->dls_size += sizeof(struct dl_serpath) + dirlen + 4422 1; 4423 } else { 4424 struct dl_serpath *s_entry; 4425 4426 s_entry = arg->serpath; 4427 s_entry->dls_name = arg->strspace; 4428 s_entry->dls_flags = arg->flags; 4429 4430 strncpy(arg->strspace, dir, dirlen); 4431 arg->strspace[dirlen] = '\0'; 4432 4433 arg->strspace += dirlen + 1; 4434 arg->serpath++; 4435 } 4436 4437 return (NULL); 4438 } 4439 4440 static int 4441 do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info) 4442 { 4443 struct dl_serinfo _info; 4444 struct fill_search_info_args args; 4445 4446 args.request = RTLD_DI_SERINFOSIZE; 4447 args.serinfo = &_info; 4448 4449 _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 4450 _info.dls_cnt = 0; 4451 4452 path_enumerate(obj->rpath, fill_search_info, NULL, &args); 4453 path_enumerate(ld_library_path, fill_search_info, NULL, &args); 4454 path_enumerate(obj->runpath, fill_search_info, NULL, &args); 4455 path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, 4456 &args); 4457 if (!obj->z_nodeflib) 4458 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 4459 &args); 4460 4461 if (request == RTLD_DI_SERINFOSIZE) { 4462 info->dls_size = _info.dls_size; 4463 info->dls_cnt = _info.dls_cnt; 4464 return (0); 4465 } 4466 4467 if (info->dls_cnt != _info.dls_cnt || 4468 info->dls_size != _info.dls_size) { 4469 _rtld_error( 4470 "Uninitialized Dl_serinfo struct passed to dlinfo()"); 4471 return (-1); 4472 } 4473 4474 args.request = RTLD_DI_SERINFO; 4475 args.serinfo = info; 4476 args.serpath = &info->dls_serpath[0]; 4477 args.strspace = (char *)&info->dls_serpath[_info.dls_cnt]; 4478 4479 args.flags = LA_SER_RUNPATH; 4480 if (path_enumerate(obj->rpath, fill_search_info, NULL, &args) != NULL) 4481 return (-1); 4482 4483 args.flags = LA_SER_LIBPATH; 4484 if (path_enumerate(ld_library_path, fill_search_info, NULL, &args) != 4485 NULL) 4486 return (-1); 4487 4488 args.flags = LA_SER_RUNPATH; 4489 if (path_enumerate(obj->runpath, fill_search_info, NULL, &args) != NULL) 4490 return (-1); 4491 4492 args.flags = LA_SER_CONFIG; 4493 if (path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, 4494 &args) != NULL) 4495 return (-1); 4496 4497 args.flags = LA_SER_DEFAULT; 4498 if (!obj->z_nodeflib && 4499 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 4500 &args) != NULL) 4501 return (-1); 4502 return (0); 4503 } 4504 4505 static int 4506 rtld_dirname(const char *path, char *bname) 4507 { 4508 const char *endp; 4509 4510 /* Empty or NULL string gets treated as "." */ 4511 if (path == NULL || *path == '\0') { 4512 bname[0] = '.'; 4513 bname[1] = '\0'; 4514 return (0); 4515 } 4516 4517 /* Strip trailing slashes */ 4518 endp = path + strlen(path) - 1; 4519 while (endp > path && *endp == '/') 4520 endp--; 4521 4522 /* Find the start of the dir */ 4523 while (endp > path && *endp != '/') 4524 endp--; 4525 4526 /* Either the dir is "/" or there are no slashes */ 4527 if (endp == path) { 4528 bname[0] = *endp == '/' ? '/' : '.'; 4529 bname[1] = '\0'; 4530 return (0); 4531 } else { 4532 do { 4533 endp--; 4534 } while (endp > path && *endp == '/'); 4535 } 4536 4537 if (endp - path + 2 > PATH_MAX) { 4538 _rtld_error("Filename is too long: %s", path); 4539 return (-1); 4540 } 4541 4542 strncpy(bname, path, endp - path + 1); 4543 bname[endp - path + 1] = '\0'; 4544 return (0); 4545 } 4546 4547 static int 4548 rtld_dirname_abs(const char *path, char *base) 4549 { 4550 char *last; 4551 4552 if (realpath(path, base) == NULL) { 4553 _rtld_error("realpath \"%s\" failed (%s)", path, 4554 rtld_strerror(errno)); 4555 return (-1); 4556 } 4557 dbg("%s -> %s", path, base); 4558 last = strrchr(base, '/'); 4559 if (last == NULL) { 4560 _rtld_error("non-abs result from realpath \"%s\"", path); 4561 return (-1); 4562 } 4563 if (last != base) 4564 *last = '\0'; 4565 return (0); 4566 } 4567 4568 static void 4569 linkmap_add(Obj_Entry *obj) 4570 { 4571 struct link_map *l, *prev; 4572 4573 l = &obj->linkmap; 4574 l->l_name = obj->path; 4575 l->l_base = obj->mapbase; 4576 l->l_ld = obj->dynamic; 4577 l->l_addr = obj->relocbase; 4578 4579 if (r_debug.r_map == NULL) { 4580 r_debug.r_map = l; 4581 return; 4582 } 4583 4584 /* 4585 * Scan to the end of the list, but not past the entry for the 4586 * dynamic linker, which we want to keep at the very end. 4587 */ 4588 for (prev = r_debug.r_map; 4589 prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap; 4590 prev = prev->l_next) 4591 ; 4592 4593 /* Link in the new entry. */ 4594 l->l_prev = prev; 4595 l->l_next = prev->l_next; 4596 if (l->l_next != NULL) 4597 l->l_next->l_prev = l; 4598 prev->l_next = l; 4599 } 4600 4601 static void 4602 linkmap_delete(Obj_Entry *obj) 4603 { 4604 struct link_map *l; 4605 4606 l = &obj->linkmap; 4607 if (l->l_prev == NULL) { 4608 if ((r_debug.r_map = l->l_next) != NULL) 4609 l->l_next->l_prev = NULL; 4610 return; 4611 } 4612 4613 if ((l->l_prev->l_next = l->l_next) != NULL) 4614 l->l_next->l_prev = l->l_prev; 4615 } 4616 4617 /* 4618 * Function for the debugger to set a breakpoint on to gain control. 4619 * 4620 * The two parameters allow the debugger to easily find and determine 4621 * what the runtime loader is doing and to whom it is doing it. 4622 * 4623 * When the loadhook trap is hit (r_debug_state, set at program 4624 * initialization), the arguments can be found on the stack: 4625 * 4626 * +8 struct link_map *m 4627 * +4 struct r_debug *rd 4628 * +0 RetAddr 4629 */ 4630 void 4631 r_debug_state(struct r_debug *rd __unused, struct link_map *m __unused) 4632 { 4633 /* 4634 * The following is a hack to force the compiler to emit calls to 4635 * this function, even when optimizing. If the function is empty, 4636 * the compiler is not obliged to emit any code for calls to it, 4637 * even when marked __noinline. However, gdb depends on those 4638 * calls being made. 4639 */ 4640 __compiler_membar(); 4641 } 4642 4643 /* 4644 * A function called after init routines have completed. This can be used to 4645 * break before a program's entry routine is called, and can be used when 4646 * main is not available in the symbol table. 4647 */ 4648 void 4649 _r_debug_postinit(struct link_map *m __unused) 4650 { 4651 /* See r_debug_state(). */ 4652 __compiler_membar(); 4653 } 4654 4655 static void 4656 release_object(Obj_Entry *obj) 4657 { 4658 if (obj->holdcount > 0) { 4659 obj->unholdfree = true; 4660 return; 4661 } 4662 munmap(obj->mapbase, obj->mapsize); 4663 linkmap_delete(obj); 4664 obj_free(obj); 4665 } 4666 4667 /* 4668 * Get address of the pointer variable in the main program. 4669 * Prefer non-weak symbol over the weak one. 4670 */ 4671 static const void ** 4672 get_program_var_addr(const char *name, RtldLockState *lockstate) 4673 { 4674 SymLook req; 4675 DoneList donelist; 4676 4677 symlook_init(&req, name); 4678 req.lockstate = lockstate; 4679 donelist_init(&donelist); 4680 if (symlook_global(&req, &donelist) != 0) 4681 return (NULL); 4682 if (ELF_ST_TYPE(req.sym_out->st_info) == STT_FUNC) 4683 return ((const void **)make_function_pointer(req.sym_out, 4684 req.defobj_out)); 4685 else if (ELF_ST_TYPE(req.sym_out->st_info) == STT_GNU_IFUNC) 4686 return ((const void **)rtld_resolve_ifunc(req.defobj_out, 4687 req.sym_out)); 4688 else 4689 return ((const void **)(req.defobj_out->relocbase + 4690 req.sym_out->st_value)); 4691 } 4692 4693 /* 4694 * Set a pointer variable in the main program to the given value. This 4695 * is used to set key variables such as "environ" before any of the 4696 * init functions are called. 4697 */ 4698 static void 4699 set_program_var(const char *name, const void *value) 4700 { 4701 const void **addr; 4702 4703 if ((addr = get_program_var_addr(name, NULL)) != NULL) { 4704 dbg("\"%s\": *%p <-- %p", name, addr, value); 4705 *addr = value; 4706 } 4707 } 4708 4709 /* 4710 * Search the global objects, including dependencies and main object, 4711 * for the given symbol. 4712 */ 4713 static int 4714 symlook_global(SymLook *req, DoneList *donelist) 4715 { 4716 SymLook req1; 4717 const Objlist_Entry *elm; 4718 int res; 4719 4720 symlook_init_from_req(&req1, req); 4721 4722 /* Search all objects loaded at program start up. */ 4723 if (req->defobj_out == NULL || (ld_dynamic_weak && 4724 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK)) { 4725 res = symlook_list(&req1, &list_main, donelist); 4726 if (res == 0 && (!ld_dynamic_weak || req->defobj_out == NULL || 4727 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4728 req->sym_out = req1.sym_out; 4729 req->defobj_out = req1.defobj_out; 4730 assert(req->defobj_out != NULL); 4731 } 4732 } 4733 4734 /* Search all DAGs whose roots are RTLD_GLOBAL objects. */ 4735 STAILQ_FOREACH(elm, &list_global, link) { 4736 if (req->defobj_out != NULL && (!ld_dynamic_weak || 4737 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK)) 4738 break; 4739 res = symlook_list(&req1, &elm->obj->dagmembers, donelist); 4740 if (res == 0 && (req->defobj_out == NULL || 4741 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4742 req->sym_out = req1.sym_out; 4743 req->defobj_out = req1.defobj_out; 4744 assert(req->defobj_out != NULL); 4745 } 4746 } 4747 4748 return (req->sym_out != NULL ? 0 : ESRCH); 4749 } 4750 4751 /* 4752 * Given a symbol name in a referencing object, find the corresponding 4753 * definition of the symbol. Returns a pointer to the symbol, or NULL if 4754 * no definition was found. Returns a pointer to the Obj_Entry of the 4755 * defining object via the reference parameter DEFOBJ_OUT. 4756 */ 4757 static int 4758 symlook_default(SymLook *req, const Obj_Entry *refobj) 4759 { 4760 DoneList donelist; 4761 const Objlist_Entry *elm; 4762 SymLook req1; 4763 int res; 4764 4765 donelist_init(&donelist); 4766 symlook_init_from_req(&req1, req); 4767 4768 /* 4769 * Look first in the referencing object if linked symbolically, 4770 * and similarly handle protected symbols. 4771 */ 4772 res = symlook_obj(&req1, refobj); 4773 if (res == 0 && (refobj->symbolic || 4774 ELF_ST_VISIBILITY(req1.sym_out->st_other) == STV_PROTECTED || 4775 refobj->deepbind)) { 4776 req->sym_out = req1.sym_out; 4777 req->defobj_out = req1.defobj_out; 4778 assert(req->defobj_out != NULL); 4779 } 4780 if (refobj->symbolic || req->defobj_out != NULL || refobj->deepbind) 4781 donelist_check(&donelist, refobj); 4782 4783 if (!refobj->deepbind) 4784 symlook_global(req, &donelist); 4785 4786 /* Search all dlopened DAGs containing the referencing object. */ 4787 STAILQ_FOREACH(elm, &refobj->dldags, link) { 4788 if (req->sym_out != NULL && (!ld_dynamic_weak || 4789 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK)) 4790 break; 4791 res = symlook_list(&req1, &elm->obj->dagmembers, &donelist); 4792 if (res == 0 && (req->sym_out == NULL || 4793 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4794 req->sym_out = req1.sym_out; 4795 req->defobj_out = req1.defobj_out; 4796 assert(req->defobj_out != NULL); 4797 } 4798 } 4799 4800 if (refobj->deepbind) 4801 symlook_global(req, &donelist); 4802 4803 /* 4804 * Search the dynamic linker itself, and possibly resolve the 4805 * symbol from there. This is how the application links to 4806 * dynamic linker services such as dlopen. 4807 */ 4808 if (req->sym_out == NULL || 4809 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 4810 res = symlook_obj(&req1, &obj_rtld); 4811 if (res == 0) { 4812 req->sym_out = req1.sym_out; 4813 req->defobj_out = req1.defobj_out; 4814 assert(req->defobj_out != NULL); 4815 } 4816 } 4817 4818 return (req->sym_out != NULL ? 0 : ESRCH); 4819 } 4820 4821 static int 4822 symlook_list(SymLook *req, const Objlist *objlist, DoneList *dlp) 4823 { 4824 const Elf_Sym *def; 4825 const Obj_Entry *defobj; 4826 const Objlist_Entry *elm; 4827 SymLook req1; 4828 int res; 4829 4830 def = NULL; 4831 defobj = NULL; 4832 STAILQ_FOREACH(elm, objlist, link) { 4833 if (donelist_check(dlp, elm->obj)) 4834 continue; 4835 symlook_init_from_req(&req1, req); 4836 if ((res = symlook_obj(&req1, elm->obj)) == 0) { 4837 if (def == NULL || (ld_dynamic_weak && 4838 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4839 def = req1.sym_out; 4840 defobj = req1.defobj_out; 4841 if (!ld_dynamic_weak || 4842 ELF_ST_BIND(def->st_info) != STB_WEAK) 4843 break; 4844 } 4845 } 4846 } 4847 if (def != NULL) { 4848 req->sym_out = def; 4849 req->defobj_out = defobj; 4850 return (0); 4851 } 4852 return (ESRCH); 4853 } 4854 4855 /* 4856 * Search the chain of DAGS cointed to by the given Needed_Entry 4857 * for a symbol of the given name. Each DAG is scanned completely 4858 * before advancing to the next one. Returns a pointer to the symbol, 4859 * or NULL if no definition was found. 4860 */ 4861 static int 4862 symlook_needed(SymLook *req, const Needed_Entry *needed, DoneList *dlp) 4863 { 4864 const Elf_Sym *def; 4865 const Needed_Entry *n; 4866 const Obj_Entry *defobj; 4867 SymLook req1; 4868 int res; 4869 4870 def = NULL; 4871 defobj = NULL; 4872 symlook_init_from_req(&req1, req); 4873 for (n = needed; n != NULL; n = n->next) { 4874 if (n->obj == NULL || (res = symlook_list(&req1, 4875 &n->obj->dagmembers, dlp)) != 0) 4876 continue; 4877 if (def == NULL || (ld_dynamic_weak && 4878 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4879 def = req1.sym_out; 4880 defobj = req1.defobj_out; 4881 if (!ld_dynamic_weak || 4882 ELF_ST_BIND(def->st_info) != STB_WEAK) 4883 break; 4884 } 4885 } 4886 if (def != NULL) { 4887 req->sym_out = def; 4888 req->defobj_out = defobj; 4889 return (0); 4890 } 4891 return (ESRCH); 4892 } 4893 4894 static int 4895 symlook_obj_load_filtees(SymLook *req, SymLook *req1, const Obj_Entry *obj, 4896 Needed_Entry *needed) 4897 { 4898 DoneList donelist; 4899 int flags; 4900 4901 flags = (req->flags & SYMLOOK_EARLY) != 0 ? RTLD_LO_EARLY : 0; 4902 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 4903 donelist_init(&donelist); 4904 symlook_init_from_req(req1, req); 4905 return (symlook_needed(req1, needed, &donelist)); 4906 } 4907 4908 /* 4909 * Search the symbol table of a single shared object for a symbol of 4910 * the given name and version, if requested. Returns a pointer to the 4911 * symbol, or NULL if no definition was found. If the object is 4912 * filter, return filtered symbol from filtee. 4913 * 4914 * The symbol's hash value is passed in for efficiency reasons; that 4915 * eliminates many recomputations of the hash value. 4916 */ 4917 int 4918 symlook_obj(SymLook *req, const Obj_Entry *obj) 4919 { 4920 SymLook req1; 4921 int res, mres; 4922 4923 /* 4924 * If there is at least one valid hash at this point, we prefer to 4925 * use the faster GNU version if available. 4926 */ 4927 if (obj->valid_hash_gnu) 4928 mres = symlook_obj1_gnu(req, obj); 4929 else if (obj->valid_hash_sysv) 4930 mres = symlook_obj1_sysv(req, obj); 4931 else 4932 return (EINVAL); 4933 4934 if (mres == 0) { 4935 if (obj->needed_filtees != NULL) { 4936 res = symlook_obj_load_filtees(req, &req1, obj, 4937 obj->needed_filtees); 4938 if (res == 0) { 4939 req->sym_out = req1.sym_out; 4940 req->defobj_out = req1.defobj_out; 4941 } 4942 return (res); 4943 } 4944 if (obj->needed_aux_filtees != NULL) { 4945 res = symlook_obj_load_filtees(req, &req1, obj, 4946 obj->needed_aux_filtees); 4947 if (res == 0) { 4948 req->sym_out = req1.sym_out; 4949 req->defobj_out = req1.defobj_out; 4950 return (res); 4951 } 4952 } 4953 } 4954 return (mres); 4955 } 4956 4957 /* Symbol match routine common to both hash functions */ 4958 static bool 4959 matched_symbol(SymLook *req, const Obj_Entry *obj, Sym_Match_Result *result, 4960 const unsigned long symnum) 4961 { 4962 Elf_Versym verndx; 4963 const Elf_Sym *symp; 4964 const char *strp; 4965 4966 symp = obj->symtab + symnum; 4967 strp = obj->strtab + symp->st_name; 4968 4969 switch (ELF_ST_TYPE(symp->st_info)) { 4970 case STT_FUNC: 4971 case STT_NOTYPE: 4972 case STT_OBJECT: 4973 case STT_COMMON: 4974 case STT_GNU_IFUNC: 4975 if (symp->st_value == 0) 4976 return (false); 4977 /* fallthrough */ 4978 case STT_TLS: 4979 if (symp->st_shndx != SHN_UNDEF) 4980 break; 4981 else if (((req->flags & SYMLOOK_IN_PLT) == 0) && 4982 (ELF_ST_TYPE(symp->st_info) == STT_FUNC)) 4983 break; 4984 /* fallthrough */ 4985 default: 4986 return (false); 4987 } 4988 if (req->name[0] != strp[0] || strcmp(req->name, strp) != 0) 4989 return (false); 4990 4991 if (req->ventry == NULL) { 4992 if (obj->versyms != NULL) { 4993 verndx = VER_NDX(obj->versyms[symnum]); 4994 if (verndx > obj->vernum) { 4995 _rtld_error( 4996 "%s: symbol %s references wrong version %d", 4997 obj->path, obj->strtab + symnum, verndx); 4998 return (false); 4999 } 5000 /* 5001 * If we are not called from dlsym (i.e. this 5002 * is a normal relocation from unversioned 5003 * binary), accept the symbol immediately if 5004 * it happens to have first version after this 5005 * shared object became versioned. Otherwise, 5006 * if symbol is versioned and not hidden, 5007 * remember it. If it is the only symbol with 5008 * this name exported by the shared object, it 5009 * will be returned as a match by the calling 5010 * function. If symbol is global (verndx < 2) 5011 * accept it unconditionally. 5012 */ 5013 if ((req->flags & SYMLOOK_DLSYM) == 0 && 5014 verndx == VER_NDX_GIVEN) { 5015 result->sym_out = symp; 5016 return (true); 5017 } else if (verndx >= VER_NDX_GIVEN) { 5018 if ((obj->versyms[symnum] & VER_NDX_HIDDEN) == 5019 0) { 5020 if (result->vsymp == NULL) 5021 result->vsymp = symp; 5022 result->vcount++; 5023 } 5024 return (false); 5025 } 5026 } 5027 result->sym_out = symp; 5028 return (true); 5029 } 5030 if (obj->versyms == NULL) { 5031 if (object_match_name(obj, req->ventry->name)) { 5032 _rtld_error( 5033 "%s: object %s should provide version %s for symbol %s", 5034 obj_rtld.path, obj->path, req->ventry->name, 5035 obj->strtab + symnum); 5036 return (false); 5037 } 5038 } else { 5039 verndx = VER_NDX(obj->versyms[symnum]); 5040 if (verndx > obj->vernum) { 5041 _rtld_error("%s: symbol %s references wrong version %d", 5042 obj->path, obj->strtab + symnum, verndx); 5043 return (false); 5044 } 5045 if (obj->vertab[verndx].hash != req->ventry->hash || 5046 strcmp(obj->vertab[verndx].name, req->ventry->name)) { 5047 /* 5048 * Version does not match. Look if this is a 5049 * global symbol and if it is not hidden. If 5050 * global symbol (verndx < 2) is available, 5051 * use it. Do not return symbol if we are 5052 * called by dlvsym, because dlvsym looks for 5053 * a specific version and default one is not 5054 * what dlvsym wants. 5055 */ 5056 if ((req->flags & SYMLOOK_DLSYM) || 5057 (verndx >= VER_NDX_GIVEN) || 5058 (obj->versyms[symnum] & VER_NDX_HIDDEN)) 5059 return (false); 5060 } 5061 } 5062 result->sym_out = symp; 5063 return (true); 5064 } 5065 5066 /* 5067 * Search for symbol using SysV hash function. 5068 * obj->buckets is known not to be NULL at this point; the test for this was 5069 * performed with the obj->valid_hash_sysv assignment. 5070 */ 5071 static int 5072 symlook_obj1_sysv(SymLook *req, const Obj_Entry *obj) 5073 { 5074 unsigned long symnum; 5075 Sym_Match_Result matchres; 5076 5077 matchres.sym_out = NULL; 5078 matchres.vsymp = NULL; 5079 matchres.vcount = 0; 5080 5081 for (symnum = obj->buckets[req->hash % obj->nbuckets]; 5082 symnum != STN_UNDEF; symnum = obj->chains[symnum]) { 5083 if (symnum >= obj->nchains) 5084 return (ESRCH); /* Bad object */ 5085 5086 if (matched_symbol(req, obj, &matchres, symnum)) { 5087 req->sym_out = matchres.sym_out; 5088 req->defobj_out = obj; 5089 return (0); 5090 } 5091 } 5092 if (matchres.vcount == 1) { 5093 req->sym_out = matchres.vsymp; 5094 req->defobj_out = obj; 5095 return (0); 5096 } 5097 return (ESRCH); 5098 } 5099 5100 /* Search for symbol using GNU hash function */ 5101 static int 5102 symlook_obj1_gnu(SymLook *req, const Obj_Entry *obj) 5103 { 5104 Elf_Addr bloom_word; 5105 const Elf32_Word *hashval; 5106 Elf32_Word bucket; 5107 Sym_Match_Result matchres; 5108 unsigned int h1, h2; 5109 unsigned long symnum; 5110 5111 matchres.sym_out = NULL; 5112 matchres.vsymp = NULL; 5113 matchres.vcount = 0; 5114 5115 /* Pick right bitmask word from Bloom filter array */ 5116 bloom_word = obj->bloom_gnu[(req->hash_gnu / __ELF_WORD_SIZE) & 5117 obj->maskwords_bm_gnu]; 5118 5119 /* Calculate modulus word size of gnu hash and its derivative */ 5120 h1 = req->hash_gnu & (__ELF_WORD_SIZE - 1); 5121 h2 = ((req->hash_gnu >> obj->shift2_gnu) & (__ELF_WORD_SIZE - 1)); 5122 5123 /* Filter out the "definitely not in set" queries */ 5124 if (((bloom_word >> h1) & (bloom_word >> h2) & 1) == 0) 5125 return (ESRCH); 5126 5127 /* Locate hash chain and corresponding value element*/ 5128 bucket = obj->buckets_gnu[req->hash_gnu % obj->nbuckets_gnu]; 5129 if (bucket == 0) 5130 return (ESRCH); 5131 hashval = &obj->chain_zero_gnu[bucket]; 5132 do { 5133 if (((*hashval ^ req->hash_gnu) >> 1) == 0) { 5134 symnum = hashval - obj->chain_zero_gnu; 5135 if (matched_symbol(req, obj, &matchres, symnum)) { 5136 req->sym_out = matchres.sym_out; 5137 req->defobj_out = obj; 5138 return (0); 5139 } 5140 } 5141 } while ((*hashval++ & 1) == 0); 5142 if (matchres.vcount == 1) { 5143 req->sym_out = matchres.vsymp; 5144 req->defobj_out = obj; 5145 return (0); 5146 } 5147 return (ESRCH); 5148 } 5149 5150 static void 5151 trace_calc_fmts(const char **main_local, const char **fmt1, const char **fmt2) 5152 { 5153 *main_local = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_PROGNAME); 5154 if (*main_local == NULL) 5155 *main_local = ""; 5156 5157 *fmt1 = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_FMT1); 5158 if (*fmt1 == NULL) 5159 *fmt1 = "\t%o => %p (%x)\n"; 5160 5161 *fmt2 = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_FMT2); 5162 if (*fmt2 == NULL) 5163 *fmt2 = "\t%o (%x)\n"; 5164 } 5165 5166 static void 5167 trace_print_obj(Obj_Entry *obj, const char *name, const char *path, 5168 const char *main_local, const char *fmt1, const char *fmt2) 5169 { 5170 const char *fmt; 5171 int c; 5172 5173 if (fmt1 == NULL) 5174 fmt = fmt2; 5175 else 5176 /* XXX bogus */ 5177 fmt = strncmp(name, "lib", 3) == 0 ? fmt1 : fmt2; 5178 5179 while ((c = *fmt++) != '\0') { 5180 switch (c) { 5181 default: 5182 rtld_putchar(c); 5183 continue; 5184 case '\\': 5185 switch (c = *fmt) { 5186 case '\0': 5187 continue; 5188 case 'n': 5189 rtld_putchar('\n'); 5190 break; 5191 case 't': 5192 rtld_putchar('\t'); 5193 break; 5194 } 5195 break; 5196 case '%': 5197 switch (c = *fmt) { 5198 case '\0': 5199 continue; 5200 case '%': 5201 default: 5202 rtld_putchar(c); 5203 break; 5204 case 'A': 5205 rtld_putstr(main_local); 5206 break; 5207 case 'a': 5208 rtld_putstr(obj_main->path); 5209 break; 5210 case 'o': 5211 rtld_putstr(name); 5212 break; 5213 case 'p': 5214 rtld_putstr(path); 5215 break; 5216 case 'x': 5217 rtld_printf("%p", 5218 obj != NULL ? obj->mapbase : NULL); 5219 break; 5220 } 5221 break; 5222 } 5223 ++fmt; 5224 } 5225 } 5226 5227 static void 5228 trace_loaded_objects(Obj_Entry *obj, bool show_preload) 5229 { 5230 const char *fmt1, *fmt2, *main_local; 5231 const char *name, *path; 5232 bool first_spurious, list_containers; 5233 5234 trace_calc_fmts(&main_local, &fmt1, &fmt2); 5235 list_containers = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_ALL) != NULL; 5236 5237 for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 5238 Needed_Entry *needed; 5239 5240 if (obj->marker) 5241 continue; 5242 if (list_containers && obj->needed != NULL) 5243 rtld_printf("%s:\n", obj->path); 5244 for (needed = obj->needed; needed; needed = needed->next) { 5245 if (needed->obj != NULL) { 5246 if (needed->obj->traced && !list_containers) 5247 continue; 5248 needed->obj->traced = true; 5249 path = needed->obj->path; 5250 } else 5251 path = "not found"; 5252 5253 name = obj->strtab + needed->name; 5254 trace_print_obj(needed->obj, name, path, main_local, 5255 fmt1, fmt2); 5256 } 5257 } 5258 5259 if (show_preload) { 5260 if (ld_get_env_var(LD_TRACE_LOADED_OBJECTS_FMT2) == NULL) 5261 fmt2 = "\t%p (%x)\n"; 5262 first_spurious = true; 5263 5264 TAILQ_FOREACH(obj, &obj_list, next) { 5265 if (obj->marker || obj == obj_main || obj->traced) 5266 continue; 5267 5268 if (list_containers && first_spurious) { 5269 rtld_printf("[preloaded]\n"); 5270 first_spurious = false; 5271 } 5272 5273 Name_Entry *fname = STAILQ_FIRST(&obj->names); 5274 name = fname == NULL ? "<unknown>" : fname->name; 5275 trace_print_obj(obj, name, obj->path, main_local, NULL, 5276 fmt2); 5277 } 5278 } 5279 } 5280 5281 /* 5282 * Unload a dlopened object and its dependencies from memory and from 5283 * our data structures. It is assumed that the DAG rooted in the 5284 * object has already been unreferenced, and that the object has a 5285 * reference count of 0. 5286 */ 5287 static void 5288 unload_object(Obj_Entry *root, RtldLockState *lockstate) 5289 { 5290 Obj_Entry marker, *obj, *next; 5291 5292 assert(root->refcount == 0); 5293 5294 /* 5295 * Pass over the DAG removing unreferenced objects from 5296 * appropriate lists. 5297 */ 5298 unlink_object(root); 5299 5300 /* Unmap all objects that are no longer referenced. */ 5301 for (obj = TAILQ_FIRST(&obj_list); obj != NULL; obj = next) { 5302 next = TAILQ_NEXT(obj, next); 5303 if (obj->marker || obj->refcount != 0) 5304 continue; 5305 LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 5306 0, obj->path); 5307 dbg("unloading \"%s\"", obj->path); 5308 /* 5309 * Unlink the object now to prevent new references from 5310 * being acquired while the bind lock is dropped in 5311 * recursive dlclose() invocations. 5312 */ 5313 TAILQ_REMOVE(&obj_list, obj, next); 5314 obj_count--; 5315 5316 if (obj->filtees_loaded) { 5317 if (next != NULL) { 5318 init_marker(&marker); 5319 TAILQ_INSERT_BEFORE(next, &marker, next); 5320 unload_filtees(obj, lockstate); 5321 next = TAILQ_NEXT(&marker, next); 5322 TAILQ_REMOVE(&obj_list, &marker, next); 5323 } else 5324 unload_filtees(obj, lockstate); 5325 } 5326 release_object(obj); 5327 } 5328 } 5329 5330 static void 5331 unlink_object(Obj_Entry *root) 5332 { 5333 Objlist_Entry *elm; 5334 5335 if (root->refcount == 0) { 5336 /* Remove the object from the RTLD_GLOBAL list. */ 5337 objlist_remove(&list_global, root); 5338 5339 /* Remove the object from all objects' DAG lists. */ 5340 STAILQ_FOREACH(elm, &root->dagmembers, link) { 5341 objlist_remove(&elm->obj->dldags, root); 5342 if (elm->obj != root) 5343 unlink_object(elm->obj); 5344 } 5345 } 5346 } 5347 5348 static void 5349 ref_dag(Obj_Entry *root) 5350 { 5351 Objlist_Entry *elm; 5352 5353 assert(root->dag_inited); 5354 STAILQ_FOREACH(elm, &root->dagmembers, link) 5355 elm->obj->refcount++; 5356 } 5357 5358 static void 5359 unref_dag(Obj_Entry *root) 5360 { 5361 Objlist_Entry *elm; 5362 5363 assert(root->dag_inited); 5364 STAILQ_FOREACH(elm, &root->dagmembers, link) 5365 elm->obj->refcount--; 5366 } 5367 5368 /* 5369 * Common code for MD __tls_get_addr(). 5370 */ 5371 static void * 5372 tls_get_addr_slow(struct tcb *tcb, int index, size_t offset, bool locked) 5373 { 5374 struct dtv *newdtv, *dtv; 5375 RtldLockState lockstate; 5376 int to_copy; 5377 5378 dtv = tcb->tcb_dtv; 5379 /* Check dtv generation in case new modules have arrived */ 5380 if (dtv->dtv_gen != tls_dtv_generation) { 5381 if (!locked) 5382 wlock_acquire(rtld_bind_lock, &lockstate); 5383 newdtv = xcalloc(1, sizeof(struct dtv) + tls_max_index * 5384 sizeof(struct dtv_slot)); 5385 to_copy = dtv->dtv_size; 5386 if (to_copy > tls_max_index) 5387 to_copy = tls_max_index; 5388 memcpy(newdtv->dtv_slots, dtv->dtv_slots, to_copy * 5389 sizeof(struct dtv_slot)); 5390 newdtv->dtv_gen = tls_dtv_generation; 5391 newdtv->dtv_size = tls_max_index; 5392 free(dtv); 5393 if (!locked) 5394 lock_release(rtld_bind_lock, &lockstate); 5395 dtv = tcb->tcb_dtv = newdtv; 5396 } 5397 5398 /* Dynamically allocate module TLS if necessary */ 5399 if (dtv->dtv_slots[index - 1].dtvs_tls == 0) { 5400 /* Signal safe, wlock will block out signals. */ 5401 if (!locked) 5402 wlock_acquire(rtld_bind_lock, &lockstate); 5403 if (!dtv->dtv_slots[index - 1].dtvs_tls) 5404 dtv->dtv_slots[index - 1].dtvs_tls = 5405 allocate_module_tls(tcb, index); 5406 if (!locked) 5407 lock_release(rtld_bind_lock, &lockstate); 5408 } 5409 return (dtv->dtv_slots[index - 1].dtvs_tls + offset); 5410 } 5411 5412 void * 5413 tls_get_addr_common(struct tcb *tcb, int index, size_t offset) 5414 { 5415 struct dtv *dtv; 5416 5417 dtv = tcb->tcb_dtv; 5418 /* Check dtv generation in case new modules have arrived */ 5419 if (__predict_true(dtv->dtv_gen == tls_dtv_generation && 5420 dtv->dtv_slots[index - 1].dtvs_tls != 0)) 5421 return (dtv->dtv_slots[index - 1].dtvs_tls + offset); 5422 return (tls_get_addr_slow(tcb, index, offset, false)); 5423 } 5424 5425 static struct tcb * 5426 tcb_from_tcb_list_entry(struct tcb_list_entry *tcbelm) 5427 { 5428 #ifdef TLS_VARIANT_I 5429 return ((struct tcb *)((char *)tcbelm - tcb_list_entry_offset)); 5430 #else 5431 return ((struct tcb *)((char *)tcbelm + tcb_list_entry_offset)); 5432 #endif 5433 } 5434 5435 static struct tcb_list_entry * 5436 tcb_list_entry_from_tcb(struct tcb *tcb) 5437 { 5438 #ifdef TLS_VARIANT_I 5439 return ((struct tcb_list_entry *)((char *)tcb + tcb_list_entry_offset)); 5440 #else 5441 return ((struct tcb_list_entry *)((char *)tcb - tcb_list_entry_offset)); 5442 #endif 5443 } 5444 5445 static void 5446 tcb_list_insert(struct tcb *tcb) 5447 { 5448 struct tcb_list_entry *tcbelm; 5449 5450 tcbelm = tcb_list_entry_from_tcb(tcb); 5451 TAILQ_INSERT_TAIL(&tcb_list, tcbelm, next); 5452 } 5453 5454 static void 5455 tcb_list_remove(struct tcb *tcb) 5456 { 5457 struct tcb_list_entry *tcbelm; 5458 5459 tcbelm = tcb_list_entry_from_tcb(tcb); 5460 TAILQ_REMOVE(&tcb_list, tcbelm, next); 5461 } 5462 5463 #ifdef TLS_VARIANT_I 5464 5465 /* 5466 * Return pointer to allocated TLS block 5467 */ 5468 static void * 5469 get_tls_block_ptr(void *tcb, size_t tcbsize) 5470 { 5471 size_t extra_size, post_size, pre_size, tls_block_size; 5472 size_t tls_init_align; 5473 5474 tls_init_align = MAX(obj_main->tlsalign, 1); 5475 5476 /* Compute fragments sizes. */ 5477 extra_size = tcbsize - TLS_TCB_SIZE; 5478 post_size = calculate_tls_post_size(tls_init_align); 5479 tls_block_size = tcbsize + post_size; 5480 pre_size = roundup2(tls_block_size, tls_init_align) - tls_block_size; 5481 5482 return ((char *)tcb - pre_size - extra_size); 5483 } 5484 5485 /* 5486 * Allocate Static TLS using the Variant I method. 5487 * 5488 * For details on the layout, see lib/libc/gen/tls.c. 5489 * 5490 * NB: rtld's tls_static_space variable includes TLS_TCB_SIZE and post_size as 5491 * it is based on tls_last_offset, and TLS offsets here are really TCB 5492 * offsets, whereas libc's tls_static_space is just the executable's static 5493 * TLS segment. 5494 * 5495 * NB: This differs from NetBSD's ld.elf_so, where TLS offsets are relative to 5496 * the end of the TCB. 5497 */ 5498 void * 5499 allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign) 5500 { 5501 Obj_Entry *obj; 5502 char *tls_block; 5503 struct dtv *dtv; 5504 struct tcb *tcb; 5505 char *addr; 5506 size_t i; 5507 size_t extra_size, maxalign, post_size, pre_size, tls_block_size; 5508 size_t tls_init_align, tls_init_offset, tls_bss_offset; 5509 5510 if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE) 5511 return (oldtcb); 5512 5513 assert(tcbsize >= TLS_TCB_SIZE); 5514 maxalign = MAX(tcbalign, tls_static_max_align); 5515 tls_init_align = MAX(obj_main->tlsalign, 1); 5516 5517 /* Compute fragments sizes. */ 5518 extra_size = tcbsize - TLS_TCB_SIZE; 5519 post_size = calculate_tls_post_size(tls_init_align); 5520 tls_block_size = tcbsize + post_size; 5521 pre_size = roundup2(tls_block_size, tls_init_align) - tls_block_size; 5522 tls_block_size += pre_size + tls_static_space - TLS_TCB_SIZE - 5523 post_size; 5524 5525 /* Allocate whole TLS block */ 5526 tls_block = xmalloc_aligned(tls_block_size, maxalign, 0); 5527 tcb = (struct tcb *)(tls_block + pre_size + extra_size); 5528 5529 if (oldtcb != NULL) { 5530 memcpy(tls_block, get_tls_block_ptr(oldtcb, tcbsize), 5531 tls_static_space); 5532 free(get_tls_block_ptr(oldtcb, tcbsize)); 5533 5534 /* Adjust the DTV. */ 5535 dtv = tcb->tcb_dtv; 5536 for (i = 0; i < dtv->dtv_size; i++) { 5537 if ((uintptr_t)dtv->dtv_slots[i].dtvs_tls >= 5538 (uintptr_t)oldtcb && 5539 (uintptr_t)dtv->dtv_slots[i].dtvs_tls < 5540 (uintptr_t)oldtcb + tls_static_space) { 5541 dtv->dtv_slots[i].dtvs_tls = (char *)tcb + 5542 (dtv->dtv_slots[i].dtvs_tls - 5543 (char *)oldtcb); 5544 } 5545 } 5546 } else { 5547 dtv = xcalloc(1, sizeof(struct dtv) + tls_max_index * 5548 sizeof(struct dtv_slot)); 5549 tcb->tcb_dtv = dtv; 5550 dtv->dtv_gen = tls_dtv_generation; 5551 dtv->dtv_size = tls_max_index; 5552 5553 for (obj = globallist_curr(objs); obj != NULL; 5554 obj = globallist_next(obj)) { 5555 if (obj->tlsoffset == 0) 5556 continue; 5557 tls_init_offset = obj->tlspoffset & (obj->tlsalign - 1); 5558 addr = (char *)tcb + obj->tlsoffset; 5559 if (tls_init_offset > 0) 5560 memset(addr, 0, tls_init_offset); 5561 if (obj->tlsinitsize > 0) { 5562 memcpy(addr + tls_init_offset, obj->tlsinit, 5563 obj->tlsinitsize); 5564 } 5565 if (obj->tlssize > obj->tlsinitsize) { 5566 tls_bss_offset = tls_init_offset + 5567 obj->tlsinitsize; 5568 memset(addr + tls_bss_offset, 0, 5569 obj->tlssize - tls_bss_offset); 5570 } 5571 dtv->dtv_slots[obj->tlsindex - 1].dtvs_tls = addr; 5572 } 5573 } 5574 5575 tcb_list_insert(tcb); 5576 return (tcb); 5577 } 5578 5579 void 5580 free_tls(void *tcb, size_t tcbsize, size_t tcbalign __unused) 5581 { 5582 struct dtv *dtv; 5583 uintptr_t tlsstart, tlsend; 5584 size_t post_size; 5585 size_t i, tls_init_align __unused; 5586 5587 tcb_list_remove(tcb); 5588 5589 assert(tcbsize >= TLS_TCB_SIZE); 5590 tls_init_align = MAX(obj_main->tlsalign, 1); 5591 5592 /* Compute fragments sizes. */ 5593 post_size = calculate_tls_post_size(tls_init_align); 5594 5595 tlsstart = (uintptr_t)tcb + TLS_TCB_SIZE + post_size; 5596 tlsend = (uintptr_t)tcb + tls_static_space; 5597 5598 dtv = ((struct tcb *)tcb)->tcb_dtv; 5599 for (i = 0; i < dtv->dtv_size; i++) { 5600 if (dtv->dtv_slots[i].dtvs_tls != NULL && 5601 ((uintptr_t)dtv->dtv_slots[i].dtvs_tls < tlsstart || 5602 (uintptr_t)dtv->dtv_slots[i].dtvs_tls >= tlsend)) { 5603 free(dtv->dtv_slots[i].dtvs_tls); 5604 } 5605 } 5606 free(dtv); 5607 free(get_tls_block_ptr(tcb, tcbsize)); 5608 } 5609 5610 #endif /* TLS_VARIANT_I */ 5611 5612 #ifdef TLS_VARIANT_II 5613 5614 /* 5615 * Allocate Static TLS using the Variant II method. 5616 */ 5617 void * 5618 allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign) 5619 { 5620 Obj_Entry *obj; 5621 size_t size, ralign; 5622 char *tls_block; 5623 struct dtv *dtv, *olddtv; 5624 struct tcb *tcb; 5625 char *addr; 5626 size_t i; 5627 5628 ralign = tcbalign; 5629 if (tls_static_max_align > ralign) 5630 ralign = tls_static_max_align; 5631 size = roundup(tls_static_space, ralign) + roundup(tcbsize, ralign); 5632 5633 assert(tcbsize >= 2 * sizeof(uintptr_t)); 5634 tls_block = xmalloc_aligned(size, ralign, 0 /* XXX */); 5635 dtv = xcalloc(1, sizeof(struct dtv) + tls_max_index * 5636 sizeof(struct dtv_slot)); 5637 5638 tcb = (struct tcb *)(tls_block + roundup(tls_static_space, ralign)); 5639 tcb->tcb_self = tcb; 5640 tcb->tcb_dtv = dtv; 5641 5642 dtv->dtv_gen = tls_dtv_generation; 5643 dtv->dtv_size = tls_max_index; 5644 5645 if (oldtcb != NULL) { 5646 /* 5647 * Copy the static TLS block over whole. 5648 */ 5649 memcpy((char *)tcb - tls_static_space, 5650 (const char *)oldtcb - tls_static_space, 5651 tls_static_space); 5652 5653 /* 5654 * If any dynamic TLS blocks have been created tls_get_addr(), 5655 * move them over. 5656 */ 5657 olddtv = ((struct tcb *)oldtcb)->tcb_dtv; 5658 for (i = 0; i < olddtv->dtv_size; i++) { 5659 if ((uintptr_t)olddtv->dtv_slots[i].dtvs_tls < 5660 (uintptr_t)oldtcb - size || 5661 (uintptr_t)olddtv->dtv_slots[i].dtvs_tls > 5662 (uintptr_t)oldtcb) { 5663 dtv->dtv_slots[i].dtvs_tls = 5664 olddtv->dtv_slots[i].dtvs_tls; 5665 olddtv->dtv_slots[i].dtvs_tls = NULL; 5666 } 5667 } 5668 5669 /* 5670 * We assume that this block was the one we created with 5671 * allocate_initial_tls(). 5672 */ 5673 free_tls(oldtcb, 2 * sizeof(uintptr_t), sizeof(uintptr_t)); 5674 } else { 5675 for (obj = objs; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 5676 if (obj->marker || obj->tlsoffset == 0) 5677 continue; 5678 addr = (char *)tcb - obj->tlsoffset; 5679 memset(addr + obj->tlsinitsize, 0, obj->tlssize - 5680 obj->tlsinitsize); 5681 if (obj->tlsinit) { 5682 memcpy(addr, obj->tlsinit, obj->tlsinitsize); 5683 obj->static_tls_copied = true; 5684 } 5685 dtv->dtv_slots[obj->tlsindex - 1].dtvs_tls = addr; 5686 } 5687 } 5688 5689 tcb_list_insert(tcb); 5690 return (tcb); 5691 } 5692 5693 void 5694 free_tls(void *tcb, size_t tcbsize __unused, size_t tcbalign) 5695 { 5696 struct dtv *dtv; 5697 size_t size, ralign; 5698 size_t i; 5699 uintptr_t tlsstart, tlsend; 5700 5701 tcb_list_remove(tcb); 5702 5703 /* 5704 * Figure out the size of the initial TLS block so that we can 5705 * find stuff which ___tls_get_addr() allocated dynamically. 5706 */ 5707 ralign = tcbalign; 5708 if (tls_static_max_align > ralign) 5709 ralign = tls_static_max_align; 5710 size = roundup(tls_static_space, ralign); 5711 5712 dtv = ((struct tcb *)tcb)->tcb_dtv; 5713 tlsend = (uintptr_t)tcb; 5714 tlsstart = tlsend - size; 5715 for (i = 0; i < dtv->dtv_size; i++) { 5716 if (dtv->dtv_slots[i].dtvs_tls != NULL && 5717 ((uintptr_t)dtv->dtv_slots[i].dtvs_tls < tlsstart || 5718 (uintptr_t)dtv->dtv_slots[i].dtvs_tls > tlsend)) { 5719 free(dtv->dtv_slots[i].dtvs_tls); 5720 } 5721 } 5722 5723 free((void *)tlsstart); 5724 free(dtv); 5725 } 5726 5727 #endif /* TLS_VARIANT_II */ 5728 5729 /* 5730 * Allocate TLS block for module with given index. 5731 */ 5732 void * 5733 allocate_module_tls(struct tcb *tcb, int index) 5734 { 5735 Obj_Entry *obj; 5736 char *p; 5737 5738 TAILQ_FOREACH(obj, &obj_list, next) { 5739 if (obj->marker) 5740 continue; 5741 if (obj->tlsindex == index) 5742 break; 5743 } 5744 if (obj == NULL) { 5745 _rtld_error("Can't find module with TLS index %d", index); 5746 rtld_die(); 5747 } 5748 5749 if (obj->tls_static) { 5750 #ifdef TLS_VARIANT_I 5751 p = (char *)tcb + obj->tlsoffset; 5752 #else 5753 p = (char *)tcb - obj->tlsoffset; 5754 #endif 5755 return (p); 5756 } 5757 5758 obj->tls_dynamic = true; 5759 5760 p = xmalloc_aligned(obj->tlssize, obj->tlsalign, obj->tlspoffset); 5761 memcpy(p, obj->tlsinit, obj->tlsinitsize); 5762 memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize); 5763 return (p); 5764 } 5765 5766 static bool 5767 allocate_tls_offset_common(size_t *offp, size_t tlssize, size_t tlsalign, 5768 size_t tlspoffset __unused) 5769 { 5770 size_t off; 5771 5772 if (tls_last_offset == 0) 5773 off = calculate_first_tls_offset(tlssize, tlsalign, 5774 tlspoffset); 5775 else 5776 off = calculate_tls_offset(tls_last_offset, tls_last_size, 5777 tlssize, tlsalign, tlspoffset); 5778 5779 *offp = off; 5780 #ifdef TLS_VARIANT_I 5781 off += tlssize; 5782 #endif 5783 5784 /* 5785 * If we have already fixed the size of the static TLS block, we 5786 * must stay within that size. When allocating the static TLS, we 5787 * leave a small amount of space spare to be used for dynamically 5788 * loading modules which use static TLS. 5789 */ 5790 if (tls_static_space != 0) { 5791 if (off > tls_static_space) 5792 return (false); 5793 } else if (tlsalign > tls_static_max_align) { 5794 tls_static_max_align = tlsalign; 5795 } 5796 5797 tls_last_offset = off; 5798 tls_last_size = tlssize; 5799 5800 return (true); 5801 } 5802 5803 bool 5804 allocate_tls_offset(Obj_Entry *obj) 5805 { 5806 if (obj->tls_dynamic) 5807 return (false); 5808 5809 if (obj->tls_static) 5810 return (true); 5811 5812 if (obj->tlssize == 0) { 5813 obj->tls_static = true; 5814 return (true); 5815 } 5816 5817 if (!allocate_tls_offset_common(&obj->tlsoffset, obj->tlssize, 5818 obj->tlsalign, obj->tlspoffset)) 5819 return (false); 5820 5821 obj->tls_static = true; 5822 5823 return (true); 5824 } 5825 5826 void 5827 free_tls_offset(Obj_Entry *obj) 5828 { 5829 /* 5830 * If we were the last thing to allocate out of the static TLS 5831 * block, we give our space back to the 'allocator'. This is a 5832 * simplistic workaround to allow libGL.so.1 to be loaded and 5833 * unloaded multiple times. 5834 */ 5835 size_t off = obj->tlsoffset; 5836 5837 #ifdef TLS_VARIANT_I 5838 off += obj->tlssize; 5839 #endif 5840 if (off == tls_last_offset) { 5841 tls_last_offset -= obj->tlssize; 5842 tls_last_size = 0; 5843 } 5844 } 5845 5846 void * 5847 _rtld_allocate_tls(void *oldtcb, size_t tcbsize, size_t tcbalign) 5848 { 5849 void *ret; 5850 RtldLockState lockstate; 5851 5852 wlock_acquire(rtld_bind_lock, &lockstate); 5853 ret = allocate_tls(globallist_curr(TAILQ_FIRST(&obj_list)), oldtcb, 5854 tcbsize, tcbalign); 5855 lock_release(rtld_bind_lock, &lockstate); 5856 return (ret); 5857 } 5858 5859 void 5860 _rtld_free_tls(void *tcb, size_t tcbsize, size_t tcbalign) 5861 { 5862 RtldLockState lockstate; 5863 5864 wlock_acquire(rtld_bind_lock, &lockstate); 5865 free_tls(tcb, tcbsize, tcbalign); 5866 lock_release(rtld_bind_lock, &lockstate); 5867 } 5868 5869 static void 5870 object_add_name(Obj_Entry *obj, const char *name) 5871 { 5872 Name_Entry *entry; 5873 size_t len; 5874 5875 len = strlen(name); 5876 entry = malloc(sizeof(Name_Entry) + len); 5877 5878 if (entry != NULL) { 5879 strcpy(entry->name, name); 5880 STAILQ_INSERT_TAIL(&obj->names, entry, link); 5881 } 5882 } 5883 5884 static int 5885 object_match_name(const Obj_Entry *obj, const char *name) 5886 { 5887 Name_Entry *entry; 5888 5889 STAILQ_FOREACH(entry, &obj->names, link) { 5890 if (strcmp(name, entry->name) == 0) 5891 return (1); 5892 } 5893 return (0); 5894 } 5895 5896 static Obj_Entry * 5897 locate_dependency(const Obj_Entry *obj, const char *name) 5898 { 5899 const Objlist_Entry *entry; 5900 const Needed_Entry *needed; 5901 5902 STAILQ_FOREACH(entry, &list_main, link) { 5903 if (object_match_name(entry->obj, name)) 5904 return (entry->obj); 5905 } 5906 5907 for (needed = obj->needed; needed != NULL; needed = needed->next) { 5908 if (strcmp(obj->strtab + needed->name, name) == 0 || 5909 (needed->obj != NULL && object_match_name(needed->obj, 5910 name))) { 5911 /* 5912 * If there is DT_NEEDED for the name we are looking 5913 * for, we are all set. Note that object might not be 5914 * found if dependency was not loaded yet, so the 5915 * function can return NULL here. This is expected and 5916 * handled properly by the caller. 5917 */ 5918 return (needed->obj); 5919 } 5920 } 5921 _rtld_error("%s: Unexpected inconsistency: dependency %s not found", 5922 obj->path, name); 5923 rtld_die(); 5924 } 5925 5926 static int 5927 check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj, 5928 const Elf_Vernaux *vna) 5929 { 5930 const Elf_Verdef *vd; 5931 const char *vername; 5932 5933 vername = refobj->strtab + vna->vna_name; 5934 vd = depobj->verdef; 5935 if (vd == NULL) { 5936 _rtld_error("%s: version %s required by %s not defined", 5937 depobj->path, vername, refobj->path); 5938 return (-1); 5939 } 5940 for (;;) { 5941 if (vd->vd_version != VER_DEF_CURRENT) { 5942 _rtld_error( 5943 "%s: Unsupported version %d of Elf_Verdef entry", 5944 depobj->path, vd->vd_version); 5945 return (-1); 5946 } 5947 if (vna->vna_hash == vd->vd_hash) { 5948 const Elf_Verdaux *aux = 5949 (const Elf_Verdaux *)((const char *)vd + 5950 vd->vd_aux); 5951 if (strcmp(vername, depobj->strtab + aux->vda_name) == 5952 0) 5953 return (0); 5954 } 5955 if (vd->vd_next == 0) 5956 break; 5957 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 5958 } 5959 if (vna->vna_flags & VER_FLG_WEAK) 5960 return (0); 5961 _rtld_error("%s: version %s required by %s not found", depobj->path, 5962 vername, refobj->path); 5963 return (-1); 5964 } 5965 5966 static int 5967 rtld_verify_object_versions(Obj_Entry *obj) 5968 { 5969 const Elf_Verneed *vn; 5970 const Elf_Verdef *vd; 5971 const Elf_Verdaux *vda; 5972 const Elf_Vernaux *vna; 5973 const Obj_Entry *depobj; 5974 int maxvernum, vernum; 5975 5976 if (obj->ver_checked) 5977 return (0); 5978 obj->ver_checked = true; 5979 5980 maxvernum = 0; 5981 /* 5982 * Walk over defined and required version records and figure out 5983 * max index used by any of them. Do very basic sanity checking 5984 * while there. 5985 */ 5986 vn = obj->verneed; 5987 while (vn != NULL) { 5988 if (vn->vn_version != VER_NEED_CURRENT) { 5989 _rtld_error( 5990 "%s: Unsupported version %d of Elf_Verneed entry", 5991 obj->path, vn->vn_version); 5992 return (-1); 5993 } 5994 vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux); 5995 for (;;) { 5996 vernum = VER_NEED_IDX(vna->vna_other); 5997 if (vernum > maxvernum) 5998 maxvernum = vernum; 5999 if (vna->vna_next == 0) 6000 break; 6001 vna = (const Elf_Vernaux *)((const char *)vna + 6002 vna->vna_next); 6003 } 6004 if (vn->vn_next == 0) 6005 break; 6006 vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next); 6007 } 6008 6009 vd = obj->verdef; 6010 while (vd != NULL) { 6011 if (vd->vd_version != VER_DEF_CURRENT) { 6012 _rtld_error( 6013 "%s: Unsupported version %d of Elf_Verdef entry", 6014 obj->path, vd->vd_version); 6015 return (-1); 6016 } 6017 vernum = VER_DEF_IDX(vd->vd_ndx); 6018 if (vernum > maxvernum) 6019 maxvernum = vernum; 6020 if (vd->vd_next == 0) 6021 break; 6022 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 6023 } 6024 6025 if (maxvernum == 0) 6026 return (0); 6027 6028 /* 6029 * Store version information in array indexable by version index. 6030 * Verify that object version requirements are satisfied along the 6031 * way. 6032 */ 6033 obj->vernum = maxvernum + 1; 6034 obj->vertab = xcalloc(obj->vernum, sizeof(Ver_Entry)); 6035 6036 vd = obj->verdef; 6037 while (vd != NULL) { 6038 if ((vd->vd_flags & VER_FLG_BASE) == 0) { 6039 vernum = VER_DEF_IDX(vd->vd_ndx); 6040 assert(vernum <= maxvernum); 6041 vda = (const Elf_Verdaux *)((const char *)vd + 6042 vd->vd_aux); 6043 obj->vertab[vernum].hash = vd->vd_hash; 6044 obj->vertab[vernum].name = obj->strtab + vda->vda_name; 6045 obj->vertab[vernum].file = NULL; 6046 obj->vertab[vernum].flags = 0; 6047 } 6048 if (vd->vd_next == 0) 6049 break; 6050 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 6051 } 6052 6053 vn = obj->verneed; 6054 while (vn != NULL) { 6055 depobj = locate_dependency(obj, obj->strtab + vn->vn_file); 6056 if (depobj == NULL) 6057 return (-1); 6058 vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux); 6059 for (;;) { 6060 if (check_object_provided_version(obj, depobj, vna)) 6061 return (-1); 6062 vernum = VER_NEED_IDX(vna->vna_other); 6063 assert(vernum <= maxvernum); 6064 obj->vertab[vernum].hash = vna->vna_hash; 6065 obj->vertab[vernum].name = obj->strtab + vna->vna_name; 6066 obj->vertab[vernum].file = obj->strtab + vn->vn_file; 6067 obj->vertab[vernum].flags = (vna->vna_other & 6068 VER_NEED_HIDDEN) != 0 ? VER_INFO_HIDDEN : 0; 6069 if (vna->vna_next == 0) 6070 break; 6071 vna = (const Elf_Vernaux *)((const char *)vna + 6072 vna->vna_next); 6073 } 6074 if (vn->vn_next == 0) 6075 break; 6076 vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next); 6077 } 6078 return (0); 6079 } 6080 6081 static int 6082 rtld_verify_versions(const Objlist *objlist) 6083 { 6084 Objlist_Entry *entry; 6085 int rc; 6086 6087 rc = 0; 6088 STAILQ_FOREACH(entry, objlist, link) { 6089 /* 6090 * Skip dummy objects or objects that have their version 6091 * requirements already checked. 6092 */ 6093 if (entry->obj->strtab == NULL || entry->obj->vertab != NULL) 6094 continue; 6095 if (rtld_verify_object_versions(entry->obj) == -1) { 6096 rc = -1; 6097 if (ld_tracing == NULL) 6098 break; 6099 } 6100 } 6101 if (rc == 0 || ld_tracing != NULL) 6102 rc = rtld_verify_object_versions(&obj_rtld); 6103 return (rc); 6104 } 6105 6106 const Ver_Entry * 6107 fetch_ventry(const Obj_Entry *obj, unsigned long symnum) 6108 { 6109 Elf_Versym vernum; 6110 6111 if (obj->vertab) { 6112 vernum = VER_NDX(obj->versyms[symnum]); 6113 if (vernum >= obj->vernum) { 6114 _rtld_error("%s: symbol %s has wrong verneed value %d", 6115 obj->path, obj->strtab + symnum, vernum); 6116 } else if (obj->vertab[vernum].hash != 0) { 6117 return (&obj->vertab[vernum]); 6118 } 6119 } 6120 return (NULL); 6121 } 6122 6123 int 6124 _rtld_get_stack_prot(void) 6125 { 6126 return (stack_prot); 6127 } 6128 6129 int 6130 _rtld_is_dlopened(void *arg) 6131 { 6132 Obj_Entry *obj; 6133 RtldLockState lockstate; 6134 int res; 6135 6136 rlock_acquire(rtld_bind_lock, &lockstate); 6137 obj = dlcheck(arg); 6138 if (obj == NULL) 6139 obj = obj_from_addr(arg); 6140 if (obj == NULL) { 6141 _rtld_error("No shared object contains address"); 6142 lock_release(rtld_bind_lock, &lockstate); 6143 return (-1); 6144 } 6145 res = obj->dlopened ? 1 : 0; 6146 lock_release(rtld_bind_lock, &lockstate); 6147 return (res); 6148 } 6149 6150 static int 6151 obj_remap_relro(Obj_Entry *obj, int prot) 6152 { 6153 const Elf_Phdr *ph; 6154 caddr_t relro_page; 6155 size_t relro_size; 6156 6157 for (ph = obj->phdr; ph < obj->phdr + obj->phnum; ph++) { 6158 if (ph->p_type != PT_GNU_RELRO) 6159 continue; 6160 relro_page = obj->relocbase + rtld_trunc_page(ph->p_vaddr); 6161 relro_size = rtld_round_page(ph->p_vaddr + ph->p_memsz) - 6162 rtld_trunc_page(ph->p_vaddr); 6163 if (mprotect(relro_page, relro_size, prot) == -1) { 6164 _rtld_error( 6165 "%s: Cannot set relro protection to %#x: %s", 6166 obj->path, prot, rtld_strerror(errno)); 6167 return (-1); 6168 } 6169 break; 6170 } 6171 return (0); 6172 } 6173 6174 static int 6175 obj_disable_relro(Obj_Entry *obj) 6176 { 6177 return (obj_remap_relro(obj, PROT_READ | PROT_WRITE)); 6178 } 6179 6180 static int 6181 obj_enforce_relro(Obj_Entry *obj) 6182 { 6183 return (obj_remap_relro(obj, PROT_READ)); 6184 } 6185 6186 static void 6187 map_stacks_exec(RtldLockState *lockstate) 6188 { 6189 void (*thr_map_stacks_exec)(void); 6190 6191 if ((max_stack_flags & PF_X) == 0 || (stack_prot & PROT_EXEC) != 0) 6192 return; 6193 thr_map_stacks_exec = (void (*)(void))( 6194 uintptr_t)get_program_var_addr("__pthread_map_stacks_exec", 6195 lockstate); 6196 if (thr_map_stacks_exec != NULL) { 6197 stack_prot |= PROT_EXEC; 6198 thr_map_stacks_exec(); 6199 } 6200 } 6201 6202 static void 6203 distribute_static_tls(Objlist *list) 6204 { 6205 struct tcb_list_entry *tcbelm; 6206 Objlist_Entry *objelm; 6207 struct tcb *tcb; 6208 Obj_Entry *obj; 6209 char *tlsbase; 6210 6211 STAILQ_FOREACH(objelm, list, link) { 6212 obj = objelm->obj; 6213 if (obj->marker || !obj->tls_static || obj->static_tls_copied) 6214 continue; 6215 TAILQ_FOREACH(tcbelm, &tcb_list, next) { 6216 tcb = tcb_from_tcb_list_entry(tcbelm); 6217 #ifdef TLS_VARIANT_I 6218 tlsbase = (char *)tcb + obj->tlsoffset; 6219 #else 6220 tlsbase = (char *)tcb - obj->tlsoffset; 6221 #endif 6222 memcpy(tlsbase, obj->tlsinit, obj->tlsinitsize); 6223 memset(tlsbase + obj->tlsinitsize, 0, 6224 obj->tlssize - obj->tlsinitsize); 6225 } 6226 obj->static_tls_copied = true; 6227 } 6228 } 6229 6230 void 6231 symlook_init(SymLook *dst, const char *name) 6232 { 6233 bzero(dst, sizeof(*dst)); 6234 dst->name = name; 6235 dst->hash = elf_hash(name); 6236 dst->hash_gnu = gnu_hash(name); 6237 } 6238 6239 static void 6240 symlook_init_from_req(SymLook *dst, const SymLook *src) 6241 { 6242 dst->name = src->name; 6243 dst->hash = src->hash; 6244 dst->hash_gnu = src->hash_gnu; 6245 dst->ventry = src->ventry; 6246 dst->flags = src->flags; 6247 dst->defobj_out = NULL; 6248 dst->sym_out = NULL; 6249 dst->lockstate = src->lockstate; 6250 } 6251 6252 static int 6253 open_binary_fd(const char *argv0, bool search_in_path, const char **binpath_res) 6254 { 6255 char *binpath, *pathenv, *pe, *res1; 6256 const char *res; 6257 int fd; 6258 6259 binpath = NULL; 6260 res = NULL; 6261 if (search_in_path && strchr(argv0, '/') == NULL) { 6262 binpath = xmalloc(PATH_MAX); 6263 pathenv = getenv("PATH"); 6264 if (pathenv == NULL) { 6265 _rtld_error("-p and no PATH environment variable"); 6266 rtld_die(); 6267 } 6268 pathenv = strdup(pathenv); 6269 if (pathenv == NULL) { 6270 _rtld_error("Cannot allocate memory"); 6271 rtld_die(); 6272 } 6273 fd = -1; 6274 errno = ENOENT; 6275 while ((pe = strsep(&pathenv, ":")) != NULL) { 6276 if (strlcpy(binpath, pe, PATH_MAX) >= PATH_MAX) 6277 continue; 6278 if (binpath[0] != '\0' && 6279 strlcat(binpath, "/", PATH_MAX) >= PATH_MAX) 6280 continue; 6281 if (strlcat(binpath, argv0, PATH_MAX) >= PATH_MAX) 6282 continue; 6283 fd = open(binpath, O_RDONLY | O_CLOEXEC | O_VERIFY); 6284 if (fd != -1 || errno != ENOENT) { 6285 res = binpath; 6286 break; 6287 } 6288 } 6289 free(pathenv); 6290 } else { 6291 fd = open(argv0, O_RDONLY | O_CLOEXEC | O_VERIFY); 6292 res = argv0; 6293 } 6294 6295 if (fd == -1) { 6296 _rtld_error("Cannot open %s: %s", argv0, rtld_strerror(errno)); 6297 rtld_die(); 6298 } 6299 if (res != NULL && res[0] != '/') { 6300 res1 = xmalloc(PATH_MAX); 6301 if (realpath(res, res1) != NULL) { 6302 if (res != argv0) 6303 free(__DECONST(char *, res)); 6304 res = res1; 6305 } else { 6306 free(res1); 6307 } 6308 } 6309 *binpath_res = res; 6310 return (fd); 6311 } 6312 6313 /* 6314 * Parse a set of command-line arguments. 6315 */ 6316 static int 6317 parse_args(char *argv[], int argc, bool *use_pathp, int *fdp, 6318 const char **argv0, bool *dir_ignore) 6319 { 6320 const char *arg; 6321 char machine[64]; 6322 size_t sz; 6323 int arglen, fd, i, j, mib[2]; 6324 char opt; 6325 bool seen_b, seen_f; 6326 6327 dbg("Parsing command-line arguments"); 6328 *use_pathp = false; 6329 *fdp = -1; 6330 *dir_ignore = false; 6331 seen_b = seen_f = false; 6332 6333 for (i = 1; i < argc; i++) { 6334 arg = argv[i]; 6335 dbg("argv[%d]: '%s'", i, arg); 6336 6337 /* 6338 * rtld arguments end with an explicit "--" or with the first 6339 * non-prefixed argument. 6340 */ 6341 if (strcmp(arg, "--") == 0) { 6342 i++; 6343 break; 6344 } 6345 if (arg[0] != '-') 6346 break; 6347 6348 /* 6349 * All other arguments are single-character options that can 6350 * be combined, so we need to search through `arg` for them. 6351 */ 6352 arglen = strlen(arg); 6353 for (j = 1; j < arglen; j++) { 6354 opt = arg[j]; 6355 if (opt == 'h') { 6356 print_usage(argv[0]); 6357 _exit(0); 6358 } else if (opt == 'b') { 6359 if (seen_f) { 6360 _rtld_error("Both -b and -f specified"); 6361 rtld_die(); 6362 } 6363 if (j != arglen - 1) { 6364 _rtld_error("Invalid options: %s", arg); 6365 rtld_die(); 6366 } 6367 i++; 6368 *argv0 = argv[i]; 6369 seen_b = true; 6370 break; 6371 } else if (opt == 'd') { 6372 *dir_ignore = true; 6373 } else if (opt == 'f') { 6374 if (seen_b) { 6375 _rtld_error("Both -b and -f specified"); 6376 rtld_die(); 6377 } 6378 6379 /* 6380 * -f XX can be used to specify a 6381 * descriptor for the binary named at 6382 * the command line (i.e., the later 6383 * argument will specify the process 6384 * name but the descriptor is what 6385 * will actually be executed). 6386 * 6387 * -f must be the last option in the 6388 * group, e.g., -abcf <fd>. 6389 */ 6390 if (j != arglen - 1) { 6391 _rtld_error("Invalid options: %s", arg); 6392 rtld_die(); 6393 } 6394 i++; 6395 fd = parse_integer(argv[i]); 6396 if (fd == -1) { 6397 _rtld_error( 6398 "Invalid file descriptor: '%s'", 6399 argv[i]); 6400 rtld_die(); 6401 } 6402 *fdp = fd; 6403 seen_f = true; 6404 break; 6405 } else if (opt == 'o') { 6406 struct ld_env_var_desc *l; 6407 char *n, *v; 6408 u_int ll; 6409 6410 if (j != arglen - 1) { 6411 _rtld_error("Invalid options: %s", arg); 6412 rtld_die(); 6413 } 6414 i++; 6415 n = argv[i]; 6416 v = strchr(n, '='); 6417 if (v == NULL) { 6418 _rtld_error("No '=' in -o parameter"); 6419 rtld_die(); 6420 } 6421 for (ll = 0; ll < nitems(ld_env_vars); ll++) { 6422 l = &ld_env_vars[ll]; 6423 if (v - n == (ptrdiff_t)strlen(l->n) && 6424 strncmp(n, l->n, v - n) == 0) { 6425 l->val = v + 1; 6426 break; 6427 } 6428 } 6429 if (ll == nitems(ld_env_vars)) { 6430 _rtld_error("Unknown LD_ option %s", n); 6431 rtld_die(); 6432 } 6433 } else if (opt == 'p') { 6434 *use_pathp = true; 6435 } else if (opt == 'u') { 6436 u_int ll; 6437 6438 for (ll = 0; ll < nitems(ld_env_vars); ll++) 6439 ld_env_vars[ll].val = NULL; 6440 } else if (opt == 'v') { 6441 machine[0] = '\0'; 6442 mib[0] = CTL_HW; 6443 mib[1] = HW_MACHINE; 6444 sz = sizeof(machine); 6445 sysctl(mib, nitems(mib), machine, &sz, NULL, 0); 6446 ld_elf_hints_path = ld_get_env_var( 6447 LD_ELF_HINTS_PATH); 6448 set_ld_elf_hints_path(); 6449 rtld_printf( 6450 "FreeBSD ld-elf.so.1 %s\n" 6451 "FreeBSD_version %d\n" 6452 "Default lib path %s\n" 6453 "Hints lib path %s\n" 6454 "Env prefix %s\n" 6455 "Default hint file %s\n" 6456 "Hint file %s\n" 6457 "libmap file %s\n" 6458 "Optional static TLS size %zd bytes\n", 6459 machine, __FreeBSD_version, 6460 ld_standard_library_path, gethints(false), 6461 ld_env_prefix, ld_elf_hints_default, 6462 ld_elf_hints_path, ld_path_libmap_conf, 6463 ld_static_tls_extra); 6464 _exit(0); 6465 } else { 6466 _rtld_error("Invalid argument: '%s'", arg); 6467 print_usage(argv[0]); 6468 rtld_die(); 6469 } 6470 } 6471 } 6472 6473 if (!seen_b) 6474 *argv0 = argv[i]; 6475 return (i); 6476 } 6477 6478 /* 6479 * Parse a file descriptor number without pulling in more of libc (e.g. atoi). 6480 */ 6481 static int 6482 parse_integer(const char *str) 6483 { 6484 static const int RADIX = 10; /* XXXJA: possibly support hex? */ 6485 const char *orig; 6486 int n; 6487 char c; 6488 6489 orig = str; 6490 n = 0; 6491 for (c = *str; c != '\0'; c = *++str) { 6492 if (c < '0' || c > '9') 6493 return (-1); 6494 6495 n *= RADIX; 6496 n += c - '0'; 6497 } 6498 6499 /* Make sure we actually parsed something. */ 6500 if (str == orig) 6501 return (-1); 6502 return (n); 6503 } 6504 6505 static void 6506 print_usage(const char *argv0) 6507 { 6508 rtld_printf( 6509 "Usage: %s [-h] [-b <exe>] [-d] [-f <FD>] [-p] [--] <binary> [<args>]\n" 6510 "\n" 6511 "Options:\n" 6512 " -h Display this help message\n" 6513 " -b <exe> Execute <exe> instead of <binary>, arg0 is <binary>\n" 6514 " -d Ignore lack of exec permissions for the binary\n" 6515 " -f <FD> Execute <FD> instead of searching for <binary>\n" 6516 " -o <OPT>=<VAL> Set LD_<OPT> to <VAL>, without polluting env\n" 6517 " -p Search in PATH for named binary\n" 6518 " -u Ignore LD_ environment variables\n" 6519 " -v Display identification information\n" 6520 " -- End of RTLD options\n" 6521 " <binary> Name of process to execute\n" 6522 " <args> Arguments to the executed process\n", 6523 argv0); 6524 } 6525 6526 #define AUXFMT(at, xfmt) [at] = { .name = #at, .fmt = xfmt } 6527 static const struct auxfmt { 6528 const char *name; 6529 const char *fmt; 6530 } auxfmts[] = { 6531 AUXFMT(AT_NULL, NULL), 6532 AUXFMT(AT_IGNORE, NULL), 6533 AUXFMT(AT_EXECFD, "%ld"), 6534 AUXFMT(AT_PHDR, "%p"), 6535 AUXFMT(AT_PHENT, "%lu"), 6536 AUXFMT(AT_PHNUM, "%lu"), 6537 AUXFMT(AT_PAGESZ, "%lu"), 6538 AUXFMT(AT_BASE, "%#lx"), 6539 AUXFMT(AT_FLAGS, "%#lx"), 6540 AUXFMT(AT_ENTRY, "%p"), 6541 AUXFMT(AT_NOTELF, NULL), 6542 AUXFMT(AT_UID, "%ld"), 6543 AUXFMT(AT_EUID, "%ld"), 6544 AUXFMT(AT_GID, "%ld"), 6545 AUXFMT(AT_EGID, "%ld"), 6546 AUXFMT(AT_EXECPATH, "%s"), 6547 AUXFMT(AT_CANARY, "%p"), 6548 AUXFMT(AT_CANARYLEN, "%lu"), 6549 AUXFMT(AT_OSRELDATE, "%lu"), 6550 AUXFMT(AT_NCPUS, "%lu"), 6551 AUXFMT(AT_PAGESIZES, "%p"), 6552 AUXFMT(AT_PAGESIZESLEN, "%lu"), 6553 AUXFMT(AT_TIMEKEEP, "%p"), 6554 AUXFMT(AT_STACKPROT, "%#lx"), 6555 AUXFMT(AT_EHDRFLAGS, "%#lx"), 6556 AUXFMT(AT_HWCAP, "%#lx"), 6557 AUXFMT(AT_HWCAP2, "%#lx"), 6558 AUXFMT(AT_BSDFLAGS, "%#lx"), 6559 AUXFMT(AT_ARGC, "%lu"), 6560 AUXFMT(AT_ARGV, "%p"), 6561 AUXFMT(AT_ENVC, "%p"), 6562 AUXFMT(AT_ENVV, "%p"), 6563 AUXFMT(AT_PS_STRINGS, "%p"), 6564 AUXFMT(AT_FXRNG, "%p"), 6565 AUXFMT(AT_KPRELOAD, "%p"), 6566 AUXFMT(AT_USRSTACKBASE, "%#lx"), 6567 AUXFMT(AT_USRSTACKLIM, "%#lx"), 6568 /* AT_CHERI_STATS */ 6569 AUXFMT(AT_HWCAP3, "%#lx"), 6570 AUXFMT(AT_HWCAP4, "%#lx"), 6571 6572 }; 6573 6574 static bool 6575 is_ptr_fmt(const char *fmt) 6576 { 6577 char last; 6578 6579 last = fmt[strlen(fmt) - 1]; 6580 return (last == 'p' || last == 's'); 6581 } 6582 6583 static void 6584 dump_auxv(Elf_Auxinfo **aux_info) 6585 { 6586 Elf_Auxinfo *auxp; 6587 const struct auxfmt *fmt; 6588 int i; 6589 6590 for (i = 0; i < AT_COUNT; i++) { 6591 auxp = aux_info[i]; 6592 if (auxp == NULL) 6593 continue; 6594 fmt = &auxfmts[i]; 6595 if (fmt->fmt == NULL) 6596 continue; 6597 rtld_fdprintf(STDOUT_FILENO, "%s:\t", fmt->name); 6598 if (is_ptr_fmt(fmt->fmt)) { 6599 rtld_fdprintfx(STDOUT_FILENO, fmt->fmt, 6600 auxp->a_un.a_ptr); 6601 } else { 6602 rtld_fdprintfx(STDOUT_FILENO, fmt->fmt, 6603 auxp->a_un.a_val); 6604 } 6605 rtld_fdprintf(STDOUT_FILENO, "\n"); 6606 } 6607 } 6608 6609 const char * 6610 rtld_get_var(const char *name) 6611 { 6612 const struct ld_env_var_desc *lvd; 6613 u_int i; 6614 6615 for (i = 0; i < nitems(ld_env_vars); i++) { 6616 lvd = &ld_env_vars[i]; 6617 if (strcmp(lvd->n, name) == 0) 6618 return (lvd->val); 6619 } 6620 return (NULL); 6621 } 6622 6623 static void 6624 rtld_recalc_dangerous_ld_env(void) 6625 { 6626 /* 6627 * Never reset dangerous_ld_env back to false if rtld was ever 6628 * contaminated with it set to true. 6629 */ 6630 dangerous_ld_env |= libmap_disable || libmap_override != NULL || 6631 ld_library_path != NULL || ld_preload != NULL || 6632 ld_elf_hints_path != NULL || ld_loadfltr || !ld_dynamic_weak || 6633 ld_get_env_var(LD_STATIC_TLS_EXTRA) != NULL; 6634 } 6635 6636 static void 6637 rtld_recalc_debug(const char *ld_debug) 6638 { 6639 if (ld_debug != NULL && *ld_debug != '\0') 6640 debug = 1; 6641 } 6642 6643 static void 6644 rtld_set_var_debug(struct ld_env_var_desc *lvd) 6645 { 6646 rtld_recalc_debug(lvd->val); 6647 } 6648 6649 static void 6650 rtld_set_var_library_path(struct ld_env_var_desc *lvd) 6651 { 6652 ld_library_path = lvd->val; 6653 } 6654 6655 static void 6656 rtld_set_var_library_path_fds(struct ld_env_var_desc *lvd) 6657 { 6658 ld_library_dirs = lvd->val; 6659 } 6660 6661 static void 6662 rtld_recalc_path_rpath(const char *library_path_rpath) 6663 { 6664 if (library_path_rpath != NULL) { 6665 if (library_path_rpath[0] == 'y' || 6666 library_path_rpath[0] == 'Y' || 6667 library_path_rpath[0] == '1') 6668 ld_library_path_rpath = true; 6669 else 6670 ld_library_path_rpath = false; 6671 } else { 6672 ld_library_path_rpath = false; 6673 } 6674 } 6675 6676 static void 6677 rtld_set_var_library_path_rpath(struct ld_env_var_desc *lvd) 6678 { 6679 rtld_recalc_path_rpath(lvd->val); 6680 } 6681 6682 static void 6683 rtld_recalc_bind_not(const char *bind_not_val) 6684 { 6685 if (ld_bind_now == NULL) 6686 ld_bind_not = bind_not_val != NULL; 6687 } 6688 6689 static void 6690 rtld_set_var_bind_now(struct ld_env_var_desc *lvd) 6691 { 6692 ld_bind_now = lvd->val; 6693 rtld_recalc_bind_not(ld_get_env_var(LD_BIND_NOT)); 6694 } 6695 6696 static void 6697 rtld_set_var_bind_not(struct ld_env_var_desc *lvd) 6698 { 6699 rtld_recalc_bind_not(lvd->val); 6700 } 6701 6702 static void 6703 rtld_set_var_dynamic_weak(struct ld_env_var_desc *lvd) 6704 { 6705 ld_dynamic_weak = lvd->val == NULL; 6706 } 6707 6708 static void 6709 rtld_set_var_loadfltr(struct ld_env_var_desc *lvd) 6710 { 6711 ld_loadfltr = lvd->val != NULL; 6712 } 6713 6714 static void 6715 rtld_set_var_libmap_disable(struct ld_env_var_desc *lvd) 6716 { 6717 libmap_disable = lvd->val != NULL; 6718 } 6719 6720 int 6721 rtld_set_var(const char *name, const char *val) 6722 { 6723 RtldLockState lockstate; 6724 struct ld_env_var_desc *lvd; 6725 u_int i; 6726 int error; 6727 6728 error = ENOENT; 6729 wlock_acquire(rtld_bind_lock, &lockstate); 6730 for (i = 0; i < nitems(ld_env_vars); i++) { 6731 lvd = &ld_env_vars[i]; 6732 if (strcmp(lvd->n, name) != 0) 6733 continue; 6734 if (!lvd->can_update || (lvd->unsecure && !trust)) { 6735 error = EPERM; 6736 break; 6737 } 6738 if (lvd->owned) 6739 free(__DECONST(char *, lvd->val)); 6740 if (val != NULL) 6741 lvd->val = xstrdup(val); 6742 else 6743 lvd->val = NULL; 6744 lvd->owned = true; 6745 if (lvd->on_update != NULL) 6746 lvd->on_update(lvd); 6747 error = 0; 6748 break; 6749 } 6750 if (error == 0) 6751 rtld_recalc_dangerous_ld_env(); 6752 lock_release(rtld_bind_lock, &lockstate); 6753 return (error); 6754 } 6755 6756 /* 6757 * Overrides for libc_pic-provided functions. 6758 */ 6759 6760 int 6761 __getosreldate(void) 6762 { 6763 size_t len; 6764 int oid[2]; 6765 int error, osrel; 6766 6767 if (osreldate != 0) 6768 return (osreldate); 6769 6770 oid[0] = CTL_KERN; 6771 oid[1] = KERN_OSRELDATE; 6772 osrel = 0; 6773 len = sizeof(osrel); 6774 error = sysctl(oid, 2, &osrel, &len, NULL, 0); 6775 if (error == 0 && osrel > 0 && len == sizeof(osrel)) 6776 osreldate = osrel; 6777 return (osreldate); 6778 } 6779 const char * 6780 rtld_strerror(int errnum) 6781 { 6782 if (errnum < 0 || errnum >= sys_nerr) 6783 return ("Unknown error"); 6784 return (sys_errlist[errnum]); 6785 } 6786 6787 char * 6788 getenv(const char *name) 6789 { 6790 return (__DECONST(char *, rtld_get_env_val(environ, name, 6791 strlen(name)))); 6792 } 6793 6794 /* malloc */ 6795 void * 6796 malloc(size_t nbytes) 6797 { 6798 return (__crt_malloc(nbytes)); 6799 } 6800 6801 void * 6802 calloc(size_t num, size_t size) 6803 { 6804 return (__crt_calloc(num, size)); 6805 } 6806 6807 void 6808 free(void *cp) 6809 { 6810 __crt_free(cp); 6811 } 6812 6813 void * 6814 realloc(void *cp, size_t nbytes) 6815 { 6816 return (__crt_realloc(cp, nbytes)); 6817 } 6818 6819 extern int _rtld_version__FreeBSD_version __exported; 6820 int _rtld_version__FreeBSD_version = __FreeBSD_version; 6821 6822 extern char _rtld_version_laddr_offset __exported; 6823 char _rtld_version_laddr_offset; 6824 6825 extern char _rtld_version_dlpi_tls_data __exported; 6826 char _rtld_version_dlpi_tls_data; 6827