1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright 1996, 1997, 1998, 1999, 2000 John D. Polstra. 5 * Copyright 2003 Alexander Kabaev <kan@FreeBSD.ORG>. 6 * Copyright 2009-2013 Konstantin Belousov <kib@FreeBSD.ORG>. 7 * Copyright 2012 John Marino <draco@marino.st>. 8 * Copyright 2014-2017 The FreeBSD Foundation 9 * All rights reserved. 10 * 11 * Portions of this software were developed by Konstantin Belousov 12 * under sponsorship from the FreeBSD Foundation. 13 * 14 * Redistribution and use in source and binary forms, with or without 15 * modification, are permitted provided that the following conditions 16 * are met: 17 * 1. Redistributions of source code must retain the above copyright 18 * notice, this list of conditions and the following disclaimer. 19 * 2. Redistributions in binary form must reproduce the above copyright 20 * notice, this list of conditions and the following disclaimer in the 21 * documentation and/or other materials provided with the distribution. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 24 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 25 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 26 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 27 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 28 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 29 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 30 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 31 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 32 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 33 */ 34 35 /* 36 * Dynamic linker for ELF. 37 * 38 * John Polstra <jdp@polstra.com>. 39 */ 40 41 #include <sys/param.h> 42 #include <sys/ktrace.h> 43 #include <sys/mman.h> 44 #include <sys/mount.h> 45 #include <sys/stat.h> 46 #include <sys/sysctl.h> 47 #include <sys/uio.h> 48 #include <sys/utsname.h> 49 50 #include <dlfcn.h> 51 #include <err.h> 52 #include <errno.h> 53 #include <fcntl.h> 54 #include <stdarg.h> 55 #include <stdio.h> 56 #include <stdlib.h> 57 #include <string.h> 58 #include <unistd.h> 59 60 #include "debug.h" 61 #include "libmap.h" 62 #include "notes.h" 63 #include "rtld.h" 64 #include "rtld_libc.h" 65 #include "rtld_malloc.h" 66 #include "rtld_paths.h" 67 #include "rtld_printf.h" 68 #include "rtld_tls.h" 69 #include "rtld_utrace.h" 70 71 /* Types. */ 72 typedef void (*func_ptr_type)(void); 73 typedef void *(*path_enum_proc)(const char *path, size_t len, void *arg); 74 75 /* Variables that cannot be static: */ 76 extern struct r_debug r_debug; /* For GDB */ 77 extern int _thread_autoinit_dummy_decl; 78 extern void (*__cleanup)(void); 79 80 struct dlerror_save { 81 int seen; 82 char *msg; 83 }; 84 85 struct tcb_list_entry { 86 TAILQ_ENTRY(tcb_list_entry) next; 87 }; 88 89 /* 90 * Function declarations. 91 */ 92 static bool allocate_tls_offset_common(size_t *offp, size_t tlssize, 93 size_t tlsalign, size_t tlspoffset); 94 static const char *basename(const char *); 95 static void digest_dynamic1(Obj_Entry *, int, const Elf_Dyn **, 96 const Elf_Dyn **, const Elf_Dyn **); 97 static bool digest_dynamic2(Obj_Entry *, const Elf_Dyn *, const Elf_Dyn *, 98 const Elf_Dyn *); 99 static bool digest_dynamic(Obj_Entry *, int); 100 static Obj_Entry *digest_phdr(const Elf_Phdr *, int, caddr_t, const char *); 101 static void distribute_static_tls(Objlist *); 102 static Obj_Entry *dlcheck(void *); 103 static int dlclose_locked(void *, RtldLockState *); 104 static Obj_Entry *dlopen_object(const char *name, int fd, Obj_Entry *refobj, 105 int lo_flags, int mode, RtldLockState *lockstate); 106 static Obj_Entry *do_load_object(int, const char *, char *, struct stat *, int); 107 static int do_search_info(const Obj_Entry *obj, int, struct dl_serinfo *); 108 static bool donelist_check(DoneList *, const Obj_Entry *); 109 static void dump_auxv(Elf_Auxinfo **aux_info); 110 static void errmsg_restore(struct dlerror_save *); 111 static struct dlerror_save *errmsg_save(void); 112 static void *fill_search_info(const char *, size_t, void *); 113 static char *find_library(const char *, const Obj_Entry *, int *); 114 static const char *gethints(bool); 115 static void hold_object(Obj_Entry *); 116 static void unhold_object(Obj_Entry *); 117 static void init_dag(Obj_Entry *); 118 static void init_marker(Obj_Entry *); 119 static void init_pagesizes(Elf_Auxinfo **aux_info); 120 static void init_rtld(caddr_t, Elf_Auxinfo **); 121 static void initlist_add_neededs(Needed_Entry *, Objlist *, Objlist *); 122 static void initlist_add_objects(Obj_Entry *, Obj_Entry *, Objlist *, 123 Objlist *); 124 static void initlist_for_loaded_obj(Obj_Entry *obj, Obj_Entry *tail, 125 Objlist *list); 126 static int initlist_objects_ifunc(Objlist *, bool, int, RtldLockState *); 127 static void linkmap_add(Obj_Entry *); 128 static void linkmap_delete(Obj_Entry *); 129 static void load_filtees(Obj_Entry *, int flags, RtldLockState *); 130 static void unload_filtees(Obj_Entry *, RtldLockState *); 131 static int load_needed_objects(Obj_Entry *, int); 132 static int load_preload_objects(const char *, bool); 133 static int load_kpreload(const void *addr); 134 static Obj_Entry *load_object(const char *, int fd, const Obj_Entry *, int); 135 static void map_stacks_exec(RtldLockState *); 136 static int obj_disable_relro(Obj_Entry *); 137 static int obj_enforce_relro(Obj_Entry *); 138 static void objlist_call_fini(Objlist *, Obj_Entry *, RtldLockState *); 139 static void objlist_call_init(Objlist *, RtldLockState *); 140 static void objlist_clear(Objlist *); 141 static Objlist_Entry *objlist_find(Objlist *, const Obj_Entry *); 142 static void objlist_init(Objlist *); 143 static void objlist_push_head(Objlist *, Obj_Entry *); 144 static void objlist_push_tail(Objlist *, Obj_Entry *); 145 static void objlist_put_after(Objlist *, Obj_Entry *, Obj_Entry *); 146 static void objlist_remove(Objlist *, Obj_Entry *); 147 static int open_binary_fd(const char *argv0, bool search_in_path, 148 const char **binpath_res); 149 static int parse_args(char *argv[], int argc, bool *use_pathp, int *fdp, 150 const char **argv0, bool *dir_ignore); 151 static int parse_integer(const char *); 152 static void *path_enumerate(const char *, path_enum_proc, const char *, void *); 153 static void print_usage(const char *argv0); 154 static void release_object(Obj_Entry *); 155 static int relocate_object_dag(Obj_Entry *root, bool bind_now, 156 Obj_Entry *rtldobj, int flags, RtldLockState *lockstate); 157 static int relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, 158 int flags, RtldLockState *lockstate); 159 static int relocate_objects(Obj_Entry *, bool, Obj_Entry *, int, 160 RtldLockState *); 161 static int resolve_object_ifunc(Obj_Entry *, bool, int, RtldLockState *); 162 static int rtld_dirname(const char *, char *); 163 static int rtld_dirname_abs(const char *, char *); 164 static void *rtld_dlopen(const char *name, int fd, int mode); 165 static void rtld_exit(void); 166 static void rtld_nop_exit(void); 167 static char *search_library_path(const char *, const char *, const char *, 168 int *); 169 static char *search_library_pathfds(const char *, const char *, int *); 170 static const void **get_program_var_addr(const char *, RtldLockState *); 171 static void set_program_var(const char *, const void *); 172 static int symlook_default(SymLook *, const Obj_Entry *refobj); 173 static int symlook_global(SymLook *, DoneList *); 174 static void symlook_init_from_req(SymLook *, const SymLook *); 175 static int symlook_list(SymLook *, const Objlist *, DoneList *); 176 static int symlook_needed(SymLook *, const Needed_Entry *, DoneList *); 177 static int symlook_obj1_sysv(SymLook *, const Obj_Entry *); 178 static int symlook_obj1_gnu(SymLook *, const Obj_Entry *); 179 static void *tls_get_addr_slow(struct tcb *, int, size_t, bool) __noinline; 180 static void trace_loaded_objects(Obj_Entry *, bool); 181 static int try_fds_open(const char *name, const char *path); 182 static void unlink_object(Obj_Entry *); 183 static void unload_object(Obj_Entry *, RtldLockState *lockstate); 184 static void unref_dag(Obj_Entry *); 185 static void ref_dag(Obj_Entry *); 186 static char *origin_subst_one(Obj_Entry *, char *, const char *, const char *, 187 bool); 188 static char *origin_subst(Obj_Entry *, const char *); 189 static bool obj_resolve_origin(Obj_Entry *obj); 190 static void preinit_main(void); 191 static void rtld_recalc_bind_not(const char *); 192 static void rtld_recalc_dangerous_ld_env(void); 193 static void rtld_recalc_debug(const char *); 194 static void rtld_recalc_path_rpath(const char *); 195 static int rtld_verify_versions(const Objlist *); 196 static int rtld_verify_object_versions(Obj_Entry *); 197 static void object_add_name(Obj_Entry *, const char *); 198 static int object_match_name(const Obj_Entry *, const char *); 199 static void ld_utrace_log(int, void *, void *, size_t, int, const char *); 200 static void rtld_fill_dl_phdr_info(const Obj_Entry *obj, 201 struct dl_phdr_info *phdr_info); 202 static uint32_t gnu_hash(const char *); 203 static bool matched_symbol(SymLook *, const Obj_Entry *, Sym_Match_Result *, 204 const unsigned long); 205 206 struct ld_env_var_desc; 207 static void rtld_set_var_bind_not(struct ld_env_var_desc *lvd); 208 static void rtld_set_var_bind_now(struct ld_env_var_desc *lvd); 209 static void rtld_set_var_debug(struct ld_env_var_desc *lvd); 210 static void rtld_set_var_dynamic_weak(struct ld_env_var_desc *lvd); 211 static void rtld_set_var_libmap_disable(struct ld_env_var_desc *lvd); 212 static void rtld_set_var_library_path(struct ld_env_var_desc *lvd); 213 static void rtld_set_var_library_path_fds(struct ld_env_var_desc *lvd); 214 static void rtld_set_var_library_path_rpath(struct ld_env_var_desc *lvd); 215 static void rtld_set_var_loadfltr(struct ld_env_var_desc *lvd); 216 217 void r_debug_state(struct r_debug *, struct link_map *) __noinline __exported; 218 void _r_debug_postinit(struct link_map *) __noinline __exported; 219 220 int __sys_openat(int, const char *, int, ...); 221 222 /* 223 * Data declarations. 224 */ 225 struct r_debug r_debug __exported; /* for GDB; */ 226 static bool libmap_disable; /* Disable libmap */ 227 static bool ld_loadfltr; /* Immediate filters processing */ 228 static const char *libmap_override; /* Maps to use in addition to libmap.conf */ 229 static bool trust; /* False for setuid and setgid programs */ 230 static bool dangerous_ld_env; /* True if environment variables have been 231 used to affect the libraries loaded */ 232 bool ld_bind_not; /* Disable PLT update */ 233 static const char *ld_bind_now; /* Environment variable for immediate binding */ 234 static bool ld_dynamic_weak = true; /* True if non-weak definition overrides 235 weak definition */ 236 static const char *ld_library_path; /* Environment variable for search path */ 237 static const char 238 *ld_library_dirs; /* Environment variable for library descriptors */ 239 static const char *ld_preload; /* Environment variable for libraries to 240 load first */ 241 static const char *ld_preload_fds; /* Environment variable for libraries 242 represented by descriptors */ 243 static const char 244 *ld_elf_hints_path; /* Environment variable for alternative hints path */ 245 static const char *ld_tracing; /* Called from ldd to print libs */ 246 static const char *ld_utrace; /* Use utrace() to log events. */ 247 static struct obj_entry_q obj_list; /* Queue of all loaded objects */ 248 static Obj_Entry *obj_main; /* The main program shared object */ 249 static Obj_Entry obj_rtld; /* The dynamic linker shared object */ 250 static unsigned int obj_count; /* Number of objects in obj_list */ 251 static unsigned int obj_loads; /* Number of loads of objects (gen count) */ 252 size_t ld_static_tls_extra = /* Static TLS extra space (bytes) */ 253 RTLD_STATIC_TLS_EXTRA; 254 255 static Objlist list_global = /* Objects dlopened with RTLD_GLOBAL */ 256 STAILQ_HEAD_INITIALIZER(list_global); 257 static Objlist list_main = /* Objects loaded at program startup */ 258 STAILQ_HEAD_INITIALIZER(list_main); 259 static Objlist list_fini = /* Objects needing fini() calls */ 260 STAILQ_HEAD_INITIALIZER(list_fini); 261 262 Elf_Sym sym_zero; /* For resolving undefined weak refs. */ 263 264 #define GDB_STATE(s, m) \ 265 r_debug.r_state = s; \ 266 r_debug_state(&r_debug, m); 267 268 extern Elf_Dyn _DYNAMIC; 269 #pragma weak _DYNAMIC 270 271 int dlclose(void *) __exported; 272 char *dlerror(void) __exported; 273 void *dlopen(const char *, int) __exported; 274 void *fdlopen(int, int) __exported; 275 void *dlsym(void *, const char *) __exported; 276 dlfunc_t dlfunc(void *, const char *) __exported; 277 void *dlvsym(void *, const char *, const char *) __exported; 278 int dladdr(const void *, Dl_info *) __exported; 279 void dllockinit(void *, void *(*)(void *), void (*)(void *), void (*)(void *), 280 void (*)(void *), void (*)(void *), void (*)(void *)) __exported; 281 int dlinfo(void *, int, void *) __exported; 282 int _dl_iterate_phdr_locked(__dl_iterate_hdr_callback, void *) __exported; 283 int dl_iterate_phdr(__dl_iterate_hdr_callback, void *) __exported; 284 int _rtld_addr_phdr(const void *, struct dl_phdr_info *) __exported; 285 int _rtld_get_stack_prot(void) __exported; 286 int _rtld_is_dlopened(void *) __exported; 287 void _rtld_error(const char *, ...) __exported; 288 const char *rtld_get_var(const char *name) __exported; 289 int rtld_set_var(const char *name, const char *val) __exported; 290 291 /* Only here to fix -Wmissing-prototypes warnings */ 292 int __getosreldate(void); 293 func_ptr_type _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp); 294 Elf_Addr _rtld_bind(Obj_Entry *obj, Elf_Size reloff); 295 296 int npagesizes; 297 static int osreldate; 298 size_t *pagesizes; 299 size_t page_size; 300 301 static int stack_prot = PROT_READ | PROT_WRITE | PROT_EXEC; 302 static int max_stack_flags; 303 304 /* 305 * Global declarations normally provided by crt1. The dynamic linker is 306 * not built with crt1, so we have to provide them ourselves. 307 */ 308 char *__progname; 309 char **environ; 310 311 /* 312 * Used to pass argc, argv to init functions. 313 */ 314 int main_argc; 315 char **main_argv; 316 317 /* 318 * Globals to control TLS allocation. 319 */ 320 size_t tls_last_offset; /* Static TLS offset of last module */ 321 size_t tls_last_size; /* Static TLS size of last module */ 322 size_t tls_static_space; /* Static TLS space allocated */ 323 static size_t tls_static_max_align; 324 Elf_Addr tls_dtv_generation = 1; /* Used to detect when dtv size changes */ 325 int tls_max_index = 1; /* Largest module index allocated */ 326 327 static TAILQ_HEAD(, tcb_list_entry) tcb_list = 328 TAILQ_HEAD_INITIALIZER(tcb_list); 329 static size_t tcb_list_entry_offset; 330 331 static bool ld_library_path_rpath = false; 332 bool ld_fast_sigblock = false; 333 334 /* 335 * Globals for path names, and such 336 */ 337 const char *ld_elf_hints_default = _PATH_ELF_HINTS; 338 const char *ld_path_libmap_conf = _PATH_LIBMAP_CONF; 339 const char *ld_path_rtld = _PATH_RTLD; 340 const char *ld_standard_library_path = STANDARD_LIBRARY_PATH; 341 const char *ld_env_prefix = LD_; 342 343 static void (*rtld_exit_ptr)(void); 344 345 #define LD_UTRACE(e, h, mb, ms, r, n) \ 346 do { \ 347 if (ld_utrace != NULL) \ 348 ld_utrace_log(e, h, mb, ms, r, n); \ 349 } while (0) 350 351 static void 352 ld_utrace_log(int event, void *handle, void *mapbase, size_t mapsize, 353 int refcnt, const char *name) 354 { 355 struct utrace_rtld ut; 356 static const char rtld_utrace_sig[RTLD_UTRACE_SIG_SZ] __nonstring = 357 RTLD_UTRACE_SIG; 358 359 memset(&ut, 0, sizeof(ut)); /* clear holes */ 360 memcpy(ut.sig, rtld_utrace_sig, sizeof(ut.sig)); 361 ut.event = event; 362 ut.handle = handle; 363 ut.mapbase = mapbase; 364 ut.mapsize = mapsize; 365 ut.refcnt = refcnt; 366 if (name != NULL) 367 strlcpy(ut.name, name, sizeof(ut.name)); 368 utrace(&ut, sizeof(ut)); 369 } 370 371 struct ld_env_var_desc { 372 const char *const n; 373 const char *val; 374 const bool unsecure : 1; 375 const bool can_update : 1; 376 bool owned : 1; 377 void (*const on_update)(struct ld_env_var_desc *); 378 }; 379 #define LD_ENV_DESC(var, unsec, ...) \ 380 [LD_##var] = { .n = #var, .unsecure = unsec, __VA_ARGS__ } 381 382 static struct ld_env_var_desc ld_env_vars[] = { 383 LD_ENV_DESC(BIND_NOW, false, .can_update = true, 384 .on_update = rtld_set_var_bind_now), 385 LD_ENV_DESC(PRELOAD, true), 386 LD_ENV_DESC(LIBMAP, true), 387 LD_ENV_DESC(LIBRARY_PATH, true, .can_update = true, 388 .on_update = rtld_set_var_library_path), 389 LD_ENV_DESC(LIBRARY_PATH_FDS, true, .can_update = true, 390 .on_update = rtld_set_var_library_path_fds), 391 LD_ENV_DESC(LIBMAP_DISABLE, true, .can_update = true, 392 .on_update = rtld_set_var_libmap_disable), 393 LD_ENV_DESC(BIND_NOT, true, .can_update = true, 394 .on_update = rtld_set_var_bind_not), 395 LD_ENV_DESC(DEBUG, true, .can_update = true, 396 .on_update = rtld_set_var_debug), 397 LD_ENV_DESC(ELF_HINTS_PATH, true), 398 LD_ENV_DESC(LOADFLTR, true, .can_update = true, 399 .on_update = rtld_set_var_loadfltr), 400 LD_ENV_DESC(LIBRARY_PATH_RPATH, true, .can_update = true, 401 .on_update = rtld_set_var_library_path_rpath), 402 LD_ENV_DESC(PRELOAD_FDS, true), 403 LD_ENV_DESC(DYNAMIC_WEAK, true, .can_update = true, 404 .on_update = rtld_set_var_dynamic_weak), 405 LD_ENV_DESC(TRACE_LOADED_OBJECTS, false), 406 LD_ENV_DESC(UTRACE, false, .can_update = true), 407 LD_ENV_DESC(DUMP_REL_PRE, false, .can_update = true), 408 LD_ENV_DESC(DUMP_REL_POST, false, .can_update = true), 409 LD_ENV_DESC(TRACE_LOADED_OBJECTS_PROGNAME, false), 410 LD_ENV_DESC(TRACE_LOADED_OBJECTS_FMT1, false), 411 LD_ENV_DESC(TRACE_LOADED_OBJECTS_FMT2, false), 412 LD_ENV_DESC(TRACE_LOADED_OBJECTS_ALL, false), 413 LD_ENV_DESC(SHOW_AUXV, true), 414 LD_ENV_DESC(STATIC_TLS_EXTRA, false), 415 LD_ENV_DESC(NO_DL_ITERATE_PHDR_AFTER_FORK, false), 416 }; 417 418 const char * 419 ld_get_env_var(int idx) 420 { 421 return (ld_env_vars[idx].val); 422 } 423 424 static const char * 425 rtld_get_env_val(char **env, const char *name, size_t name_len) 426 { 427 char **m, *n, *v; 428 429 for (m = env; *m != NULL; m++) { 430 n = *m; 431 v = strchr(n, '='); 432 if (v == NULL) { 433 /* corrupt environment? */ 434 continue; 435 } 436 if (v - n == (ptrdiff_t)name_len && 437 strncmp(name, n, name_len) == 0) 438 return (v + 1); 439 } 440 return (NULL); 441 } 442 443 static void 444 rtld_init_env_vars_for_prefix(char **env, const char *env_prefix) 445 { 446 struct ld_env_var_desc *lvd; 447 size_t prefix_len, nlen; 448 char **m, *n, *v; 449 int i; 450 451 prefix_len = strlen(env_prefix); 452 for (m = env; *m != NULL; m++) { 453 n = *m; 454 if (strncmp(env_prefix, n, prefix_len) != 0) { 455 /* Not a rtld environment variable. */ 456 continue; 457 } 458 n += prefix_len; 459 v = strchr(n, '='); 460 if (v == NULL) { 461 /* corrupt environment? */ 462 continue; 463 } 464 for (i = 0; i < (int)nitems(ld_env_vars); i++) { 465 lvd = &ld_env_vars[i]; 466 if (lvd->val != NULL) { 467 /* Saw higher-priority variable name already. */ 468 continue; 469 } 470 nlen = strlen(lvd->n); 471 if (v - n == (ptrdiff_t)nlen && 472 strncmp(lvd->n, n, nlen) == 0) { 473 lvd->val = v + 1; 474 break; 475 } 476 } 477 } 478 } 479 480 static void 481 rtld_init_env_vars(char **env) 482 { 483 rtld_init_env_vars_for_prefix(env, ld_env_prefix); 484 } 485 486 static void 487 set_ld_elf_hints_path(void) 488 { 489 if (ld_elf_hints_path == NULL || strlen(ld_elf_hints_path) == 0) 490 ld_elf_hints_path = ld_elf_hints_default; 491 } 492 493 uintptr_t 494 rtld_round_page(uintptr_t x) 495 { 496 return (roundup2(x, page_size)); 497 } 498 499 uintptr_t 500 rtld_trunc_page(uintptr_t x) 501 { 502 return (rounddown2(x, page_size)); 503 } 504 505 /* 506 * Main entry point for dynamic linking. The first argument is the 507 * stack pointer. The stack is expected to be laid out as described 508 * in the SVR4 ABI specification, Intel 386 Processor Supplement. 509 * Specifically, the stack pointer points to a word containing 510 * ARGC. Following that in the stack is a null-terminated sequence 511 * of pointers to argument strings. Then comes a null-terminated 512 * sequence of pointers to environment strings. Finally, there is a 513 * sequence of "auxiliary vector" entries. 514 * 515 * The second argument points to a place to store the dynamic linker's 516 * exit procedure pointer and the third to a place to store the main 517 * program's object. 518 * 519 * The return value is the main program's entry point. 520 */ 521 func_ptr_type 522 _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp) 523 { 524 Elf_Auxinfo *aux, *auxp, *auxpf, *aux_info[AT_COUNT], auxtmp; 525 Objlist_Entry *entry; 526 Obj_Entry *last_interposer, *obj, *preload_tail; 527 const Elf_Phdr *phdr; 528 Objlist initlist; 529 RtldLockState lockstate; 530 struct stat st; 531 Elf_Addr *argcp; 532 char **argv, **env, **envp, *kexecpath; 533 const char *argv0, *binpath, *static_tls_extra; 534 struct ld_env_var_desc *lvd; 535 caddr_t imgentry; 536 char buf[MAXPATHLEN]; 537 int argc, fd, i, mib[4], old_osrel, osrel, phnum, rtld_argc; 538 size_t sz; 539 bool dir_enable, dir_ignore, direct_exec, explicit_fd, search_in_path; 540 541 /* 542 * On entry, the dynamic linker itself has not been relocated yet. 543 * Be very careful not to reference any global data until after 544 * init_rtld has returned. It is OK to reference file-scope statics 545 * and string constants, and to call static and global functions. 546 */ 547 548 /* Find the auxiliary vector on the stack. */ 549 argcp = sp; 550 argc = *sp++; 551 argv = (char **)sp; 552 sp += argc + 1; /* Skip over arguments and NULL terminator */ 553 env = (char **)sp; 554 while (*sp++ != 0) /* Skip over environment, and NULL terminator */ 555 ; 556 aux = (Elf_Auxinfo *)sp; 557 558 /* Digest the auxiliary vector. */ 559 for (i = 0; i < AT_COUNT; i++) 560 aux_info[i] = NULL; 561 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) { 562 if (auxp->a_type < AT_COUNT) 563 aux_info[auxp->a_type] = auxp; 564 } 565 arch_fix_auxv(aux, aux_info); 566 567 /* Initialize and relocate ourselves. */ 568 assert(aux_info[AT_BASE] != NULL); 569 init_rtld((caddr_t)aux_info[AT_BASE]->a_un.a_ptr, aux_info); 570 571 dlerror_dflt_init(); 572 573 __progname = obj_rtld.path; 574 argv0 = argv[0] != NULL ? argv[0] : "(null)"; 575 environ = env; 576 main_argc = argc; 577 main_argv = argv; 578 579 if (aux_info[AT_BSDFLAGS] != NULL && 580 (aux_info[AT_BSDFLAGS]->a_un.a_val & ELF_BSDF_SIGFASTBLK) != 0) 581 ld_fast_sigblock = true; 582 583 trust = !issetugid(); 584 direct_exec = false; 585 586 md_abi_variant_hook(aux_info); 587 rtld_init_env_vars(env); 588 589 fd = -1; 590 if (aux_info[AT_EXECFD] != NULL) { 591 fd = aux_info[AT_EXECFD]->a_un.a_val; 592 } else { 593 assert(aux_info[AT_PHDR] != NULL); 594 phdr = (const Elf_Phdr *)aux_info[AT_PHDR]->a_un.a_ptr; 595 if (phdr == obj_rtld.phdr) { 596 if (!trust) { 597 _rtld_error( 598 "Tainted process refusing to run binary %s", 599 argv0); 600 rtld_die(); 601 } 602 direct_exec = true; 603 604 dbg("opening main program in direct exec mode"); 605 if (argc >= 2) { 606 rtld_argc = parse_args(argv, argc, 607 &search_in_path, &fd, &argv0, &dir_ignore); 608 explicit_fd = (fd != -1); 609 binpath = NULL; 610 if (!explicit_fd) 611 fd = open_binary_fd(argv0, 612 search_in_path, &binpath); 613 if (fstat(fd, &st) == -1) { 614 _rtld_error( 615 "Failed to fstat FD %d (%s): %s", 616 fd, 617 explicit_fd ? 618 "user-provided descriptor" : 619 argv0, 620 rtld_strerror(errno)); 621 rtld_die(); 622 } 623 624 /* 625 * Rough emulation of the permission checks done 626 * by execve(2), only Unix DACs are checked, 627 * ACLs are ignored. Preserve the semantic of 628 * disabling owner to execute if owner x bit is 629 * cleared, even if others x bit is enabled. 630 * mmap(2) does not allow to mmap with PROT_EXEC 631 * if binary' file comes from noexec mount. We 632 * cannot set a text reference on the binary. 633 */ 634 dir_enable = false; 635 if (st.st_uid == geteuid()) { 636 if ((st.st_mode & S_IXUSR) != 0) 637 dir_enable = true; 638 } else if (st.st_gid == getegid()) { 639 if ((st.st_mode & S_IXGRP) != 0) 640 dir_enable = true; 641 } else if ((st.st_mode & S_IXOTH) != 0) { 642 dir_enable = true; 643 } 644 if (!dir_enable && !dir_ignore) { 645 _rtld_error( 646 "No execute permission for binary %s", 647 argv0); 648 rtld_die(); 649 } 650 651 /* 652 * For direct exec mode, argv[0] is the 653 * interpreter name, we must remove it and shift 654 * arguments left before invoking binary main. 655 * Since stack layout places environment 656 * pointers and aux vectors right after the 657 * terminating NULL, we must shift environment 658 * and aux as well. 659 */ 660 main_argc = argc - rtld_argc; 661 for (i = 0; i <= main_argc; i++) 662 argv[i] = argv[i + rtld_argc]; 663 *argcp -= rtld_argc; 664 environ = env = envp = argv + main_argc + 1; 665 dbg("move env from %p to %p", envp + rtld_argc, 666 envp); 667 do { 668 *envp = *(envp + rtld_argc); 669 } while (*envp++ != NULL); 670 aux = auxp = (Elf_Auxinfo *)envp; 671 auxpf = (Elf_Auxinfo *)(envp + rtld_argc); 672 dbg("move aux from %p to %p", auxpf, aux); 673 /* 674 * XXXKIB insert place for AT_EXECPATH if not 675 * present 676 */ 677 for (;; auxp++, auxpf++) { 678 /* 679 * NB: Use a temporary since *auxpf and 680 * *auxp overlap if rtld_argc is 1 681 */ 682 auxtmp = *auxpf; 683 *auxp = auxtmp; 684 if (auxp->a_type == AT_NULL) 685 break; 686 } 687 /* 688 * Since the auxiliary vector has moved, 689 * redigest it. 690 */ 691 for (i = 0; i < AT_COUNT; i++) 692 aux_info[i] = NULL; 693 for (auxp = aux; auxp->a_type != AT_NULL; 694 auxp++) { 695 if (auxp->a_type < AT_COUNT) 696 aux_info[auxp->a_type] = auxp; 697 } 698 699 /* 700 * Point AT_EXECPATH auxv and aux_info to the 701 * binary path. 702 */ 703 if (binpath == NULL) { 704 aux_info[AT_EXECPATH] = NULL; 705 } else { 706 if (aux_info[AT_EXECPATH] == NULL) { 707 aux_info[AT_EXECPATH] = xmalloc( 708 sizeof(Elf_Auxinfo)); 709 aux_info[AT_EXECPATH]->a_type = 710 AT_EXECPATH; 711 } 712 aux_info[AT_EXECPATH]->a_un.a_ptr = 713 __DECONST(void *, binpath); 714 } 715 } else { 716 _rtld_error("No binary"); 717 rtld_die(); 718 } 719 } 720 } 721 722 ld_bind_now = ld_get_env_var(LD_BIND_NOW); 723 724 /* 725 * If the process is tainted, then we un-set the dangerous environment 726 * variables. The process will be marked as tainted until setuid(2) 727 * is called. If any child process calls setuid(2) we do not want any 728 * future processes to honor the potentially un-safe variables. 729 */ 730 if (!trust) { 731 for (i = 0; i < (int)nitems(ld_env_vars); i++) { 732 lvd = &ld_env_vars[i]; 733 if (lvd->unsecure) 734 lvd->val = NULL; 735 } 736 } 737 738 rtld_recalc_debug(ld_get_env_var(LD_DEBUG)); 739 rtld_recalc_bind_not(ld_get_env_var(LD_BIND_NOT)); 740 ld_dynamic_weak = ld_get_env_var(LD_DYNAMIC_WEAK) == NULL; 741 libmap_disable = ld_get_env_var(LD_LIBMAP_DISABLE) != NULL; 742 libmap_override = ld_get_env_var(LD_LIBMAP); 743 ld_library_path = ld_get_env_var(LD_LIBRARY_PATH); 744 ld_library_dirs = ld_get_env_var(LD_LIBRARY_PATH_FDS); 745 ld_preload = ld_get_env_var(LD_PRELOAD); 746 ld_preload_fds = ld_get_env_var(LD_PRELOAD_FDS); 747 ld_elf_hints_path = ld_get_env_var(LD_ELF_HINTS_PATH); 748 ld_loadfltr = ld_get_env_var(LD_LOADFLTR) != NULL; 749 rtld_recalc_path_rpath(ld_get_env_var(LD_LIBRARY_PATH_RPATH)); 750 static_tls_extra = ld_get_env_var(LD_STATIC_TLS_EXTRA); 751 if (static_tls_extra != NULL && static_tls_extra[0] != '\0') { 752 sz = parse_integer(static_tls_extra); 753 if (sz >= RTLD_STATIC_TLS_EXTRA && sz <= SIZE_T_MAX) 754 ld_static_tls_extra = sz; 755 } 756 rtld_recalc_dangerous_ld_env(); 757 ld_tracing = ld_get_env_var(LD_TRACE_LOADED_OBJECTS); 758 ld_utrace = ld_get_env_var(LD_UTRACE); 759 760 set_ld_elf_hints_path(); 761 dbg("%s is initialized, base address = %p", __progname, 762 (caddr_t)aux_info[AT_BASE]->a_un.a_ptr); 763 dbg("RTLD dynamic = %p", obj_rtld.dynamic); 764 dbg("RTLD pltgot = %p", obj_rtld.pltgot); 765 766 dbg("initializing thread locks"); 767 lockdflt_init(); 768 769 /* 770 * Load the main program, or process its program header if it is 771 * already loaded. 772 */ 773 if (fd != -1) { /* Load the main program. */ 774 dbg("loading main program"); 775 obj_main = map_object(fd, argv0, NULL, true); 776 close(fd); 777 if (obj_main == NULL) 778 rtld_die(); 779 max_stack_flags = obj_main->stack_flags; 780 } else { /* Main program already loaded. */ 781 dbg("processing main program's program header"); 782 assert(aux_info[AT_PHDR] != NULL); 783 phdr = (const Elf_Phdr *)aux_info[AT_PHDR]->a_un.a_ptr; 784 assert(aux_info[AT_PHNUM] != NULL); 785 phnum = aux_info[AT_PHNUM]->a_un.a_val; 786 assert(aux_info[AT_PHENT] != NULL); 787 assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr)); 788 assert(aux_info[AT_ENTRY] != NULL); 789 imgentry = (caddr_t)aux_info[AT_ENTRY]->a_un.a_ptr; 790 if ((obj_main = digest_phdr(phdr, phnum, imgentry, argv0)) == 791 NULL) 792 rtld_die(); 793 } 794 795 if (aux_info[AT_EXECPATH] != NULL && fd == -1) { 796 kexecpath = aux_info[AT_EXECPATH]->a_un.a_ptr; 797 dbg("AT_EXECPATH %p %s", kexecpath, kexecpath); 798 if (kexecpath[0] == '/') 799 obj_main->path = kexecpath; 800 else if (getcwd(buf, sizeof(buf)) == NULL || 801 strlcat(buf, "/", sizeof(buf)) >= sizeof(buf) || 802 strlcat(buf, kexecpath, sizeof(buf)) >= sizeof(buf)) 803 obj_main->path = xstrdup(argv0); 804 else 805 obj_main->path = xstrdup(buf); 806 } else { 807 dbg("No AT_EXECPATH or direct exec"); 808 obj_main->path = xstrdup(argv0); 809 } 810 dbg("obj_main path %s", obj_main->path); 811 obj_main->mainprog = true; 812 813 if (aux_info[AT_STACKPROT] != NULL && 814 aux_info[AT_STACKPROT]->a_un.a_val != 0) 815 stack_prot = aux_info[AT_STACKPROT]->a_un.a_val; 816 817 #ifndef COMPAT_libcompat 818 /* 819 * Get the actual dynamic linker pathname from the executable if 820 * possible. (It should always be possible.) That ensures that 821 * gdb will find the right dynamic linker even if a non-standard 822 * one is being used. 823 */ 824 if (obj_main->interp != NULL && 825 strcmp(obj_main->interp, obj_rtld.path) != 0) { 826 free(obj_rtld.path); 827 obj_rtld.path = xstrdup(obj_main->interp); 828 __progname = obj_rtld.path; 829 } 830 #endif 831 832 if (!digest_dynamic(obj_main, 0)) 833 rtld_die(); 834 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", 835 obj_main->path, obj_main->valid_hash_sysv, obj_main->valid_hash_gnu, 836 obj_main->dynsymcount); 837 838 linkmap_add(obj_main); 839 linkmap_add(&obj_rtld); 840 LD_UTRACE(UTRACE_LOAD_OBJECT, obj_main, obj_main->mapbase, 841 obj_main->mapsize, 0, obj_main->path); 842 LD_UTRACE(UTRACE_LOAD_OBJECT, &obj_rtld, obj_rtld.mapbase, 843 obj_rtld.mapsize, 0, obj_rtld.path); 844 845 /* Link the main program into the list of objects. */ 846 TAILQ_INSERT_HEAD(&obj_list, obj_main, next); 847 obj_count++; 848 obj_loads++; 849 850 /* Initialize a fake symbol for resolving undefined weak references. */ 851 sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE); 852 sym_zero.st_shndx = SHN_UNDEF; 853 sym_zero.st_value = -(uintptr_t)obj_main->relocbase; 854 855 if (!libmap_disable) 856 libmap_disable = (bool)lm_init(libmap_override); 857 858 if (aux_info[AT_KPRELOAD] != NULL && 859 aux_info[AT_KPRELOAD]->a_un.a_ptr != NULL) { 860 dbg("loading kernel vdso"); 861 if (load_kpreload(aux_info[AT_KPRELOAD]->a_un.a_ptr) == -1) 862 rtld_die(); 863 } 864 865 dbg("loading LD_PRELOAD_FDS libraries"); 866 if (load_preload_objects(ld_preload_fds, true) == -1) 867 rtld_die(); 868 869 dbg("loading LD_PRELOAD libraries"); 870 if (load_preload_objects(ld_preload, false) == -1) 871 rtld_die(); 872 preload_tail = globallist_curr(TAILQ_LAST(&obj_list, obj_entry_q)); 873 874 dbg("loading needed objects"); 875 if (load_needed_objects(obj_main, 876 ld_tracing != NULL ? RTLD_LO_TRACE : 0) == -1) 877 rtld_die(); 878 879 /* Make a list of all objects loaded at startup. */ 880 last_interposer = obj_main; 881 TAILQ_FOREACH(obj, &obj_list, next) { 882 if (obj->marker) 883 continue; 884 if (obj->z_interpose && obj != obj_main) { 885 objlist_put_after(&list_main, last_interposer, obj); 886 last_interposer = obj; 887 } else { 888 objlist_push_tail(&list_main, obj); 889 } 890 obj->refcount++; 891 } 892 893 dbg("checking for required versions"); 894 if (rtld_verify_versions(&list_main) == -1 && !ld_tracing) 895 rtld_die(); 896 897 if (ld_get_env_var(LD_SHOW_AUXV) != NULL) 898 dump_auxv(aux_info); 899 900 if (ld_tracing) { /* We're done */ 901 trace_loaded_objects(obj_main, true); 902 exit(0); 903 } 904 905 if (ld_get_env_var(LD_DUMP_REL_PRE) != NULL) { 906 dump_relocations(obj_main); 907 exit(0); 908 } 909 910 /* 911 * Processing tls relocations requires having the tls offsets 912 * initialized. Prepare offsets before starting initial 913 * relocation processing. 914 */ 915 dbg("initializing initial thread local storage offsets"); 916 STAILQ_FOREACH(entry, &list_main, link) { 917 /* 918 * Allocate all the initial objects out of the static TLS 919 * block even if they didn't ask for it. 920 */ 921 allocate_tls_offset(entry->obj); 922 } 923 924 if (!allocate_tls_offset_common(&tcb_list_entry_offset, 925 sizeof(struct tcb_list_entry), _Alignof(struct tcb_list_entry), 926 0)) { 927 /* 928 * This should be impossible as the static block size is not 929 * yet fixed, but catch and diagnose it failing if that ever 930 * changes or somehow turns out to be false. 931 */ 932 _rtld_error("Could not allocate offset for tcb_list_entry"); 933 rtld_die(); 934 } 935 dbg("tcb_list_entry_offset %zu", tcb_list_entry_offset); 936 937 if (relocate_objects(obj_main, 938 ld_bind_now != NULL && *ld_bind_now != '\0', &obj_rtld, 939 SYMLOOK_EARLY, NULL) == -1) 940 rtld_die(); 941 942 dbg("doing copy relocations"); 943 if (do_copy_relocations(obj_main) == -1) 944 rtld_die(); 945 946 if (ld_get_env_var(LD_DUMP_REL_POST) != NULL) { 947 dump_relocations(obj_main); 948 exit(0); 949 } 950 951 ifunc_init(aux_info); 952 953 /* 954 * Setup TLS for main thread. This must be done after the 955 * relocations are processed, since tls initialization section 956 * might be the subject for relocations. 957 */ 958 dbg("initializing initial thread local storage"); 959 allocate_initial_tls(globallist_curr(TAILQ_FIRST(&obj_list))); 960 961 dbg("initializing key program variables"); 962 set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : ""); 963 set_program_var("environ", env); 964 set_program_var("__elf_aux_vector", aux); 965 966 /* Make a list of init functions to call. */ 967 objlist_init(&initlist); 968 initlist_for_loaded_obj(globallist_curr(TAILQ_FIRST(&obj_list)), 969 preload_tail, &initlist); 970 971 r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */ 972 973 map_stacks_exec(NULL); 974 975 if (!obj_main->crt_no_init) { 976 /* 977 * Make sure we don't call the main program's init and fini 978 * functions for binaries linked with old crt1 which calls 979 * _init itself. 980 */ 981 obj_main->init = obj_main->fini = 0; 982 obj_main->preinit_array = obj_main->init_array = 983 obj_main->fini_array = NULL; 984 } 985 986 if (direct_exec) { 987 /* Set osrel for direct-execed binary */ 988 mib[0] = CTL_KERN; 989 mib[1] = KERN_PROC; 990 mib[2] = KERN_PROC_OSREL; 991 mib[3] = getpid(); 992 osrel = obj_main->osrel; 993 sz = sizeof(old_osrel); 994 dbg("setting osrel to %d", osrel); 995 (void)sysctl(mib, 4, &old_osrel, &sz, &osrel, sizeof(osrel)); 996 } 997 998 wlock_acquire(rtld_bind_lock, &lockstate); 999 1000 dbg("resolving ifuncs"); 1001 if (initlist_objects_ifunc(&initlist, 1002 ld_bind_now != NULL && *ld_bind_now != '\0', SYMLOOK_EARLY, 1003 &lockstate) == -1) 1004 rtld_die(); 1005 1006 rtld_exit_ptr = rtld_exit; 1007 if (obj_main->crt_no_init) 1008 preinit_main(); 1009 objlist_call_init(&initlist, &lockstate); 1010 _r_debug_postinit(&obj_main->linkmap); 1011 objlist_clear(&initlist); 1012 dbg("loading filtees"); 1013 TAILQ_FOREACH(obj, &obj_list, next) { 1014 if (obj->marker) 1015 continue; 1016 if (ld_loadfltr || obj->z_loadfltr) 1017 load_filtees(obj, 0, &lockstate); 1018 } 1019 1020 dbg("enforcing main obj relro"); 1021 if (obj_enforce_relro(obj_main) == -1) 1022 rtld_die(); 1023 1024 lock_release(rtld_bind_lock, &lockstate); 1025 1026 dbg("transferring control to program entry point = %p", 1027 obj_main->entry); 1028 1029 /* Return the exit procedure and the program entry point. */ 1030 *exit_proc = rtld_exit_ptr; 1031 *objp = obj_main; 1032 return ((func_ptr_type)obj_main->entry); 1033 } 1034 1035 /* 1036 * Fill in a DoneList with an allocation large enough to hold all of 1037 * the currently-loaded Keep this as a macro since it calls 1038 * alloca and we want that to occur within the scope of the caller. 1039 */ 1040 #define DLP_ALLOCA_LIMIT 100 /* 800 bytes on LP64 */ 1041 #define donelist_init(_DLP, _REQ) do { \ 1042 DoneList *_dlp = _DLP; \ 1043 SymLook *_r = _REQ; \ 1044 _dlp->num_alloc = obj_count, \ 1045 _dlp->req = NULL; \ 1046 if (_dlp->num_alloc > DLP_ALLOCA_LIMIT) { \ 1047 _dlp->objs = xcalloc(_dlp->num_alloc, sizeof(_dlp->objs[0])); \ 1048 if (_r != NULL && _r->donelist_mem == NULL) { \ 1049 _r->donelist_mem = _dlp->objs; \ 1050 _dlp->req = _r; \ 1051 } \ 1052 } else { \ 1053 _dlp->objs = alloca(_dlp->num_alloc * sizeof(_dlp->objs[0])); \ 1054 } \ 1055 _dlp->num_used = 0; \ 1056 } while (0) 1057 1058 static void 1059 donelist_free(DoneList *dlp) 1060 { 1061 if (dlp->num_alloc > DLP_ALLOCA_LIMIT) 1062 free(dlp->objs); 1063 if (dlp->req != NULL) 1064 dlp->req->donelist_mem = NULL; 1065 } 1066 1067 void * 1068 rtld_resolve_ifunc(const Obj_Entry *obj, const Elf_Sym *def) 1069 { 1070 void *ptr; 1071 Elf_Addr target; 1072 1073 ptr = (void *)make_function_pointer(def, obj); 1074 target = call_ifunc_resolver(ptr); 1075 return ((void *)target); 1076 } 1077 1078 Elf_Addr 1079 _rtld_bind(Obj_Entry *obj, Elf_Size reloff) 1080 { 1081 const Elf_Rel *rel; 1082 const Elf_Sym *def; 1083 const Obj_Entry *defobj; 1084 Elf_Addr *where; 1085 Elf_Addr target; 1086 RtldLockState lockstate; 1087 1088 relock: 1089 rlock_acquire(rtld_bind_lock, &lockstate); 1090 if (sigsetjmp(lockstate.env, 0) != 0) 1091 lock_upgrade(rtld_bind_lock, &lockstate); 1092 if (obj->pltrel) 1093 rel = (const Elf_Rel *)((const char *)obj->pltrel + reloff); 1094 else 1095 rel = (const Elf_Rel *)((const char *)obj->pltrela + reloff); 1096 1097 where = (Elf_Addr *)(obj->relocbase + rel->r_offset); 1098 def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, SYMLOOK_IN_PLT, 1099 NULL, &lockstate); 1100 if (def == NULL) 1101 rtld_die(); 1102 if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) { 1103 if (lockstate_wlocked(&lockstate)) { 1104 lock_release(rtld_bind_lock, &lockstate); 1105 goto relock; 1106 } 1107 target = (Elf_Addr)rtld_resolve_ifunc(defobj, def); 1108 } else { 1109 target = (Elf_Addr)(defobj->relocbase + def->st_value); 1110 } 1111 1112 dbg("\"%s\" in \"%s\" ==> %p in \"%s\"", defobj->strtab + def->st_name, 1113 obj->path == NULL ? NULL : basename(obj->path), (void *)target, 1114 defobj->path == NULL ? NULL : basename(defobj->path)); 1115 1116 /* 1117 * Write the new contents for the jmpslot. Note that depending on 1118 * architecture, the value which we need to return back to the 1119 * lazy binding trampoline may or may not be the target 1120 * address. The value returned from reloc_jmpslot() is the value 1121 * that the trampoline needs. 1122 */ 1123 target = reloc_jmpslot(where, target, defobj, obj, rel); 1124 lock_release(rtld_bind_lock, &lockstate); 1125 return (target); 1126 } 1127 1128 /* 1129 * Error reporting function. Use it like printf. If formats the message 1130 * into a buffer, and sets things up so that the next call to dlerror() 1131 * will return the message. 1132 */ 1133 void 1134 _rtld_error(const char *fmt, ...) 1135 { 1136 va_list ap; 1137 1138 va_start(ap, fmt); 1139 rtld_vsnprintf(lockinfo.dlerror_loc(), lockinfo.dlerror_loc_sz, fmt, 1140 ap); 1141 va_end(ap); 1142 *lockinfo.dlerror_seen() = 0; 1143 dbg("rtld_error: %s", lockinfo.dlerror_loc()); 1144 LD_UTRACE(UTRACE_RTLD_ERROR, NULL, NULL, 0, 0, lockinfo.dlerror_loc()); 1145 } 1146 1147 /* 1148 * Return a dynamically-allocated copy of the current error message, if any. 1149 */ 1150 static struct dlerror_save * 1151 errmsg_save(void) 1152 { 1153 struct dlerror_save *res; 1154 1155 res = xmalloc(sizeof(*res)); 1156 res->seen = *lockinfo.dlerror_seen(); 1157 if (res->seen == 0) 1158 res->msg = xstrdup(lockinfo.dlerror_loc()); 1159 return (res); 1160 } 1161 1162 /* 1163 * Restore the current error message from a copy which was previously saved 1164 * by errmsg_save(). The copy is freed. 1165 */ 1166 static void 1167 errmsg_restore(struct dlerror_save *saved_msg) 1168 { 1169 if (saved_msg == NULL || saved_msg->seen == 1) { 1170 *lockinfo.dlerror_seen() = 1; 1171 } else { 1172 *lockinfo.dlerror_seen() = 0; 1173 strlcpy(lockinfo.dlerror_loc(), saved_msg->msg, 1174 lockinfo.dlerror_loc_sz); 1175 free(saved_msg->msg); 1176 } 1177 free(saved_msg); 1178 } 1179 1180 static const char * 1181 basename(const char *name) 1182 { 1183 const char *p; 1184 1185 p = strrchr(name, '/'); 1186 return (p != NULL ? p + 1 : name); 1187 } 1188 1189 static struct utsname uts; 1190 1191 static char * 1192 origin_subst_one(Obj_Entry *obj, char *real, const char *kw, const char *subst, 1193 bool may_free) 1194 { 1195 char *p, *p1, *res, *resp; 1196 int subst_len, kw_len, subst_count, old_len, new_len; 1197 1198 kw_len = strlen(kw); 1199 1200 /* 1201 * First, count the number of the keyword occurrences, to 1202 * preallocate the final string. 1203 */ 1204 for (p = real, subst_count = 0;; p = p1 + kw_len, subst_count++) { 1205 p1 = strstr(p, kw); 1206 if (p1 == NULL) 1207 break; 1208 } 1209 1210 /* 1211 * If the keyword is not found, just return. 1212 * 1213 * Return non-substituted string if resolution failed. We 1214 * cannot do anything more reasonable, the failure mode of the 1215 * caller is unresolved library anyway. 1216 */ 1217 if (subst_count == 0 || (obj != NULL && !obj_resolve_origin(obj))) 1218 return (may_free ? real : xstrdup(real)); 1219 if (obj != NULL) 1220 subst = obj->origin_path; 1221 1222 /* 1223 * There is indeed something to substitute. Calculate the 1224 * length of the resulting string, and allocate it. 1225 */ 1226 subst_len = strlen(subst); 1227 old_len = strlen(real); 1228 new_len = old_len + (subst_len - kw_len) * subst_count; 1229 res = xmalloc(new_len + 1); 1230 1231 /* 1232 * Now, execute the substitution loop. 1233 */ 1234 for (p = real, resp = res, *resp = '\0';;) { 1235 p1 = strstr(p, kw); 1236 if (p1 != NULL) { 1237 /* Copy the prefix before keyword. */ 1238 memcpy(resp, p, p1 - p); 1239 resp += p1 - p; 1240 /* Keyword replacement. */ 1241 memcpy(resp, subst, subst_len); 1242 resp += subst_len; 1243 *resp = '\0'; 1244 p = p1 + kw_len; 1245 } else 1246 break; 1247 } 1248 1249 /* Copy to the end of string and finish. */ 1250 strcat(resp, p); 1251 if (may_free) 1252 free(real); 1253 return (res); 1254 } 1255 1256 static const struct { 1257 const char *kw; 1258 bool pass_obj; 1259 const char *subst; 1260 } tokens[] = { 1261 { .kw = "$ORIGIN", .pass_obj = true, .subst = NULL }, 1262 { .kw = "${ORIGIN}", .pass_obj = true, .subst = NULL }, 1263 { .kw = "$OSNAME", .pass_obj = false, .subst = uts.sysname }, 1264 { .kw = "${OSNAME}", .pass_obj = false, .subst = uts.sysname }, 1265 { .kw = "$OSREL", .pass_obj = false, .subst = uts.release }, 1266 { .kw = "${OSREL}", .pass_obj = false, .subst = uts.release }, 1267 { .kw = "$PLATFORM", .pass_obj = false, .subst = uts.machine }, 1268 { .kw = "${PLATFORM}", .pass_obj = false, .subst = uts.machine }, 1269 { .kw = "$LIB", .pass_obj = false, .subst = TOKEN_LIB }, 1270 { .kw = "${LIB}", .pass_obj = false, .subst = TOKEN_LIB }, 1271 }; 1272 1273 static char * 1274 origin_subst(Obj_Entry *obj, const char *real) 1275 { 1276 char *res; 1277 int i; 1278 1279 if (obj == NULL || !trust) 1280 return (xstrdup(real)); 1281 if (uts.sysname[0] == '\0') { 1282 if (uname(&uts) != 0) { 1283 _rtld_error("utsname failed: %d", errno); 1284 return (NULL); 1285 } 1286 } 1287 1288 /* __DECONST is safe here since without may_free real is unchanged */ 1289 res = __DECONST(char *, real); 1290 for (i = 0; i < (int)nitems(tokens); i++) { 1291 res = origin_subst_one(tokens[i].pass_obj ? obj : NULL, res, 1292 tokens[i].kw, tokens[i].subst, i != 0); 1293 } 1294 return (res); 1295 } 1296 1297 void 1298 rtld_die(void) 1299 { 1300 const char *msg = dlerror(); 1301 1302 if (msg == NULL) 1303 msg = "Fatal error"; 1304 rtld_fdputstr(STDERR_FILENO, _BASENAME_RTLD ": "); 1305 rtld_fdputstr(STDERR_FILENO, msg); 1306 rtld_fdputchar(STDERR_FILENO, '\n'); 1307 _exit(1); 1308 } 1309 1310 /* 1311 * Process a shared object's DYNAMIC section, and save the important 1312 * information in its Obj_Entry structure. 1313 */ 1314 static void 1315 digest_dynamic1(Obj_Entry *obj, int early, const Elf_Dyn **dyn_rpath, 1316 const Elf_Dyn **dyn_soname, const Elf_Dyn **dyn_runpath) 1317 { 1318 const Elf_Dyn *dynp; 1319 Needed_Entry **needed_tail = &obj->needed; 1320 Needed_Entry **needed_filtees_tail = &obj->needed_filtees; 1321 Needed_Entry **needed_aux_filtees_tail = &obj->needed_aux_filtees; 1322 const Elf_Hashelt *hashtab; 1323 const Elf32_Word *hashval; 1324 Elf32_Word bkt, nmaskwords; 1325 int bloom_size32; 1326 int plttype = DT_REL; 1327 1328 *dyn_rpath = NULL; 1329 *dyn_soname = NULL; 1330 *dyn_runpath = NULL; 1331 1332 obj->bind_now = false; 1333 dynp = obj->dynamic; 1334 if (dynp == NULL) 1335 return; 1336 for (; dynp->d_tag != DT_NULL; dynp++) { 1337 switch (dynp->d_tag) { 1338 case DT_REL: 1339 obj->rel = (const Elf_Rel *)(obj->relocbase + 1340 dynp->d_un.d_ptr); 1341 break; 1342 1343 case DT_RELSZ: 1344 obj->relsize = dynp->d_un.d_val; 1345 break; 1346 1347 case DT_RELENT: 1348 assert(dynp->d_un.d_val == sizeof(Elf_Rel)); 1349 break; 1350 1351 case DT_JMPREL: 1352 obj->pltrel = (const Elf_Rel *)(obj->relocbase + 1353 dynp->d_un.d_ptr); 1354 break; 1355 1356 case DT_PLTRELSZ: 1357 obj->pltrelsize = dynp->d_un.d_val; 1358 break; 1359 1360 case DT_RELA: 1361 obj->rela = (const Elf_Rela *)(obj->relocbase + 1362 dynp->d_un.d_ptr); 1363 break; 1364 1365 case DT_RELASZ: 1366 obj->relasize = dynp->d_un.d_val; 1367 break; 1368 1369 case DT_RELAENT: 1370 assert(dynp->d_un.d_val == sizeof(Elf_Rela)); 1371 break; 1372 1373 case DT_RELR: 1374 obj->relr = (const Elf_Relr *)(obj->relocbase + 1375 dynp->d_un.d_ptr); 1376 break; 1377 1378 case DT_RELRSZ: 1379 obj->relrsize = dynp->d_un.d_val; 1380 break; 1381 1382 case DT_RELRENT: 1383 assert(dynp->d_un.d_val == sizeof(Elf_Relr)); 1384 break; 1385 1386 case DT_PLTREL: 1387 plttype = dynp->d_un.d_val; 1388 assert( 1389 dynp->d_un.d_val == DT_REL || plttype == DT_RELA); 1390 break; 1391 1392 case DT_SYMTAB: 1393 obj->symtab = (const Elf_Sym *)(obj->relocbase + 1394 dynp->d_un.d_ptr); 1395 break; 1396 1397 case DT_SYMENT: 1398 assert(dynp->d_un.d_val == sizeof(Elf_Sym)); 1399 break; 1400 1401 case DT_STRTAB: 1402 obj->strtab = (const char *)(obj->relocbase + 1403 dynp->d_un.d_ptr); 1404 break; 1405 1406 case DT_STRSZ: 1407 obj->strsize = dynp->d_un.d_val; 1408 break; 1409 1410 case DT_VERNEED: 1411 obj->verneed = (const Elf_Verneed *)(obj->relocbase + 1412 dynp->d_un.d_val); 1413 break; 1414 1415 case DT_VERNEEDNUM: 1416 obj->verneednum = dynp->d_un.d_val; 1417 break; 1418 1419 case DT_VERDEF: 1420 obj->verdef = (const Elf_Verdef *)(obj->relocbase + 1421 dynp->d_un.d_val); 1422 break; 1423 1424 case DT_VERDEFNUM: 1425 obj->verdefnum = dynp->d_un.d_val; 1426 break; 1427 1428 case DT_VERSYM: 1429 obj->versyms = (const Elf_Versym *)(obj->relocbase + 1430 dynp->d_un.d_val); 1431 break; 1432 1433 case DT_HASH: { 1434 hashtab = (const Elf_Hashelt *)(obj->relocbase + 1435 dynp->d_un.d_ptr); 1436 obj->nbuckets = hashtab[0]; 1437 obj->nchains = hashtab[1]; 1438 obj->buckets = hashtab + 2; 1439 obj->chains = obj->buckets + obj->nbuckets; 1440 obj->valid_hash_sysv = obj->nbuckets > 0 && 1441 obj->nchains > 0 && obj->buckets != NULL; 1442 } break; 1443 1444 case DT_GNU_HASH: { 1445 hashtab = (const Elf_Hashelt *)(obj->relocbase + 1446 dynp->d_un.d_ptr); 1447 obj->nbuckets_gnu = hashtab[0]; 1448 obj->symndx_gnu = hashtab[1]; 1449 nmaskwords = hashtab[2]; 1450 bloom_size32 = (__ELF_WORD_SIZE / 32) * nmaskwords; 1451 obj->maskwords_bm_gnu = nmaskwords - 1; 1452 obj->shift2_gnu = hashtab[3]; 1453 obj->bloom_gnu = (const Elf_Addr *)(hashtab + 4); 1454 obj->buckets_gnu = hashtab + 4 + bloom_size32; 1455 obj->chain_zero_gnu = obj->buckets_gnu + 1456 obj->nbuckets_gnu - obj->symndx_gnu; 1457 /* Number of bitmask words is required to be power of 2 1458 */ 1459 obj->valid_hash_gnu = powerof2(nmaskwords) && 1460 obj->nbuckets_gnu > 0 && obj->buckets_gnu != NULL; 1461 } break; 1462 1463 case DT_NEEDED: 1464 if (!obj->rtld) { 1465 Needed_Entry *nep = NEW(Needed_Entry); 1466 nep->name = dynp->d_un.d_val; 1467 nep->obj = NULL; 1468 nep->next = NULL; 1469 1470 *needed_tail = nep; 1471 needed_tail = &nep->next; 1472 } 1473 break; 1474 1475 case DT_FILTER: 1476 if (!obj->rtld) { 1477 Needed_Entry *nep = NEW(Needed_Entry); 1478 nep->name = dynp->d_un.d_val; 1479 nep->obj = NULL; 1480 nep->next = NULL; 1481 1482 *needed_filtees_tail = nep; 1483 needed_filtees_tail = &nep->next; 1484 1485 if (obj->linkmap.l_refname == NULL) 1486 obj->linkmap.l_refname = 1487 (char *)dynp->d_un.d_val; 1488 } 1489 break; 1490 1491 case DT_AUXILIARY: 1492 if (!obj->rtld) { 1493 Needed_Entry *nep = NEW(Needed_Entry); 1494 nep->name = dynp->d_un.d_val; 1495 nep->obj = NULL; 1496 nep->next = NULL; 1497 1498 *needed_aux_filtees_tail = nep; 1499 needed_aux_filtees_tail = &nep->next; 1500 } 1501 break; 1502 1503 case DT_PLTGOT: 1504 obj->pltgot = (Elf_Addr *)(obj->relocbase + 1505 dynp->d_un.d_ptr); 1506 break; 1507 1508 case DT_TEXTREL: 1509 obj->textrel = true; 1510 break; 1511 1512 case DT_SYMBOLIC: 1513 obj->symbolic = true; 1514 break; 1515 1516 case DT_RPATH: 1517 /* 1518 * We have to wait until later to process this, because 1519 * we might not have gotten the address of the string 1520 * table yet. 1521 */ 1522 *dyn_rpath = dynp; 1523 break; 1524 1525 case DT_SONAME: 1526 *dyn_soname = dynp; 1527 break; 1528 1529 case DT_RUNPATH: 1530 *dyn_runpath = dynp; 1531 break; 1532 1533 case DT_INIT: 1534 obj->init = (uintptr_t)(obj->relocbase + 1535 dynp->d_un.d_ptr); 1536 break; 1537 1538 case DT_PREINIT_ARRAY: 1539 obj->preinit_array = (uintptr_t *)(obj->relocbase + 1540 dynp->d_un.d_ptr); 1541 break; 1542 1543 case DT_PREINIT_ARRAYSZ: 1544 obj->preinit_array_num = dynp->d_un.d_val / 1545 sizeof(uintptr_t); 1546 break; 1547 1548 case DT_INIT_ARRAY: 1549 obj->init_array = (uintptr_t *)(obj->relocbase + 1550 dynp->d_un.d_ptr); 1551 break; 1552 1553 case DT_INIT_ARRAYSZ: 1554 obj->init_array_num = dynp->d_un.d_val / 1555 sizeof(uintptr_t); 1556 break; 1557 1558 case DT_FINI: 1559 obj->fini = (uintptr_t)(obj->relocbase + 1560 dynp->d_un.d_ptr); 1561 break; 1562 1563 case DT_FINI_ARRAY: 1564 obj->fini_array = (uintptr_t *)(obj->relocbase + 1565 dynp->d_un.d_ptr); 1566 break; 1567 1568 case DT_FINI_ARRAYSZ: 1569 obj->fini_array_num = dynp->d_un.d_val / 1570 sizeof(uintptr_t); 1571 break; 1572 1573 case DT_DEBUG: 1574 if (!early) 1575 dbg("Filling in DT_DEBUG entry"); 1576 (__DECONST(Elf_Dyn *, dynp))->d_un.d_ptr = 1577 (Elf_Addr)&r_debug; 1578 break; 1579 1580 case DT_FLAGS: 1581 if (dynp->d_un.d_val & DF_ORIGIN) 1582 obj->z_origin = true; 1583 if (dynp->d_un.d_val & DF_SYMBOLIC) 1584 obj->symbolic = true; 1585 if (dynp->d_un.d_val & DF_TEXTREL) 1586 obj->textrel = true; 1587 if (dynp->d_un.d_val & DF_BIND_NOW) 1588 obj->bind_now = true; 1589 if (dynp->d_un.d_val & DF_STATIC_TLS) 1590 obj->static_tls = true; 1591 break; 1592 1593 case DT_FLAGS_1: 1594 if (dynp->d_un.d_val & DF_1_NOOPEN) 1595 obj->z_noopen = true; 1596 if (dynp->d_un.d_val & DF_1_ORIGIN) 1597 obj->z_origin = true; 1598 if (dynp->d_un.d_val & DF_1_GLOBAL) 1599 obj->z_global = true; 1600 if (dynp->d_un.d_val & DF_1_BIND_NOW) 1601 obj->bind_now = true; 1602 if (dynp->d_un.d_val & DF_1_NODELETE) 1603 obj->z_nodelete = true; 1604 if (dynp->d_un.d_val & DF_1_LOADFLTR) 1605 obj->z_loadfltr = true; 1606 if (dynp->d_un.d_val & DF_1_INTERPOSE) 1607 obj->z_interpose = true; 1608 if (dynp->d_un.d_val & DF_1_NODEFLIB) 1609 obj->z_nodeflib = true; 1610 if (dynp->d_un.d_val & DF_1_PIE) 1611 obj->z_pie = true; 1612 if (dynp->d_un.d_val & DF_1_INITFIRST) 1613 obj->z_initfirst = true; 1614 break; 1615 1616 default: 1617 if (arch_digest_dynamic(obj, dynp)) 1618 break; 1619 1620 if (!early) { 1621 dbg("Ignoring d_tag %ld = %#lx", 1622 (long)dynp->d_tag, (long)dynp->d_tag); 1623 } 1624 break; 1625 } 1626 } 1627 1628 obj->traced = false; 1629 1630 if (plttype == DT_RELA) { 1631 obj->pltrela = (const Elf_Rela *)obj->pltrel; 1632 obj->pltrel = NULL; 1633 obj->pltrelasize = obj->pltrelsize; 1634 obj->pltrelsize = 0; 1635 } 1636 1637 /* Determine size of dynsym table (equal to nchains of sysv hash) */ 1638 if (obj->valid_hash_sysv) 1639 obj->dynsymcount = obj->nchains; 1640 else if (obj->valid_hash_gnu) { 1641 obj->dynsymcount = 0; 1642 for (bkt = 0; bkt < obj->nbuckets_gnu; bkt++) { 1643 if (obj->buckets_gnu[bkt] == 0) 1644 continue; 1645 hashval = &obj->chain_zero_gnu[obj->buckets_gnu[bkt]]; 1646 do 1647 obj->dynsymcount++; 1648 while ((*hashval++ & 1u) == 0); 1649 } 1650 obj->dynsymcount += obj->symndx_gnu; 1651 } 1652 1653 if (obj->linkmap.l_refname != NULL) 1654 obj->linkmap.l_refname = obj->strtab + 1655 (unsigned long)obj->linkmap.l_refname; 1656 } 1657 1658 static bool 1659 obj_resolve_origin(Obj_Entry *obj) 1660 { 1661 if (obj->origin_path != NULL) 1662 return (true); 1663 obj->origin_path = xmalloc(PATH_MAX); 1664 return (rtld_dirname_abs(obj->path, obj->origin_path) != -1); 1665 } 1666 1667 static bool 1668 digest_dynamic2(Obj_Entry *obj, const Elf_Dyn *dyn_rpath, 1669 const Elf_Dyn *dyn_soname, const Elf_Dyn *dyn_runpath) 1670 { 1671 if (obj->z_origin && !obj_resolve_origin(obj)) 1672 return (false); 1673 1674 if (dyn_runpath != NULL) { 1675 obj->runpath = (const char *)obj->strtab + 1676 dyn_runpath->d_un.d_val; 1677 obj->runpath = origin_subst(obj, obj->runpath); 1678 } else if (dyn_rpath != NULL) { 1679 obj->rpath = (const char *)obj->strtab + dyn_rpath->d_un.d_val; 1680 obj->rpath = origin_subst(obj, obj->rpath); 1681 } 1682 if (dyn_soname != NULL) 1683 object_add_name(obj, obj->strtab + dyn_soname->d_un.d_val); 1684 return (true); 1685 } 1686 1687 static bool 1688 digest_dynamic(Obj_Entry *obj, int early) 1689 { 1690 const Elf_Dyn *dyn_rpath; 1691 const Elf_Dyn *dyn_soname; 1692 const Elf_Dyn *dyn_runpath; 1693 1694 digest_dynamic1(obj, early, &dyn_rpath, &dyn_soname, &dyn_runpath); 1695 return (digest_dynamic2(obj, dyn_rpath, dyn_soname, dyn_runpath)); 1696 } 1697 1698 /* 1699 * Process a shared object's program header. This is used only for the 1700 * main program, when the kernel has already loaded the main program 1701 * into memory before calling the dynamic linker. It creates and 1702 * returns an Obj_Entry structure. 1703 */ 1704 static Obj_Entry * 1705 digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path) 1706 { 1707 Obj_Entry *obj; 1708 const Elf_Phdr *phlimit = phdr + phnum; 1709 const Elf_Phdr *ph; 1710 Elf_Addr note_start, note_end; 1711 int nsegs = 0; 1712 1713 obj = obj_new(); 1714 for (ph = phdr; ph < phlimit; ph++) { 1715 if (ph->p_type != PT_PHDR) 1716 continue; 1717 1718 obj->phdr = phdr; 1719 obj->phnum = ph->p_memsz / sizeof(*ph); 1720 obj->relocbase = __DECONST(char *, phdr) - ph->p_vaddr; 1721 break; 1722 } 1723 1724 obj->stack_flags = PF_X | PF_R | PF_W; 1725 1726 for (ph = phdr; ph < phlimit; ph++) { 1727 switch (ph->p_type) { 1728 case PT_INTERP: 1729 obj->interp = (const char *)(ph->p_vaddr + 1730 obj->relocbase); 1731 break; 1732 1733 case PT_LOAD: 1734 if (nsegs == 0) { /* First load segment */ 1735 obj->vaddrbase = rtld_trunc_page(ph->p_vaddr); 1736 obj->mapbase = obj->vaddrbase + obj->relocbase; 1737 } else { /* Last load segment */ 1738 obj->mapsize = rtld_round_page( 1739 ph->p_vaddr + ph->p_memsz) - 1740 obj->vaddrbase; 1741 } 1742 nsegs++; 1743 break; 1744 1745 case PT_DYNAMIC: 1746 obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + 1747 obj->relocbase); 1748 break; 1749 1750 case PT_TLS: 1751 if (ph->p_memsz < ph->p_filesz) { 1752 _rtld_error("%s: invalid PT_TLS segment", 1753 path); 1754 return (NULL); 1755 } 1756 1757 obj->tlsindex = 1; 1758 obj->tlssize = ph->p_memsz; 1759 obj->tlsalign = ph->p_align; 1760 obj->tlsinitsize = ph->p_filesz; 1761 obj->tlsinit = (void *)(ph->p_vaddr + obj->relocbase); 1762 obj->tlspoffset = ph->p_offset; 1763 break; 1764 1765 case PT_GNU_STACK: 1766 obj->stack_flags = ph->p_flags; 1767 break; 1768 1769 case PT_NOTE: 1770 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; 1771 note_end = note_start + ph->p_filesz; 1772 digest_notes(obj, note_start, note_end); 1773 break; 1774 } 1775 } 1776 if (nsegs < 1) { 1777 _rtld_error("%s: too few PT_LOAD segments", path); 1778 return (NULL); 1779 } 1780 1781 obj->entry = entry; 1782 return (obj); 1783 } 1784 1785 void 1786 digest_notes(Obj_Entry *obj, Elf_Addr note_start, Elf_Addr note_end) 1787 { 1788 const Elf_Note *note, *next_note; 1789 const char *note_name; 1790 uintptr_t p; 1791 1792 for (note = (const Elf_Note *)note_start;; note = next_note) { 1793 if ((Elf_Addr)note + sizeof(Elf_Note) > note_end) 1794 break; 1795 next_note = (const Elf_Note *)((const char *)(note + 1) + 1796 roundup2(note->n_namesz, sizeof(Elf32_Addr)) + 1797 roundup2(note->n_descsz, sizeof(Elf32_Addr))); 1798 if ((Elf_Addr)next_note > note_end) 1799 break; 1800 1801 if (arch_digest_note(obj, note)) 1802 continue; 1803 1804 if (note->n_namesz != sizeof(NOTE_FREEBSD_VENDOR) || 1805 note->n_descsz != sizeof(int32_t)) 1806 continue; 1807 if (note->n_type != NT_FREEBSD_ABI_TAG && 1808 note->n_type != NT_FREEBSD_FEATURE_CTL && 1809 note->n_type != NT_FREEBSD_NOINIT_TAG) 1810 continue; 1811 note_name = (const char *)(note + 1); 1812 if (strncmp(NOTE_FREEBSD_VENDOR, note_name, 1813 sizeof(NOTE_FREEBSD_VENDOR)) != 0) 1814 continue; 1815 switch (note->n_type) { 1816 case NT_FREEBSD_ABI_TAG: 1817 /* FreeBSD osrel note */ 1818 p = (uintptr_t)(note + 1); 1819 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1820 obj->osrel = *(const int32_t *)(p); 1821 dbg("note osrel %d", obj->osrel); 1822 break; 1823 case NT_FREEBSD_FEATURE_CTL: 1824 /* FreeBSD ABI feature control note */ 1825 p = (uintptr_t)(note + 1); 1826 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1827 obj->fctl0 = *(const uint32_t *)(p); 1828 dbg("note fctl0 %#x", obj->fctl0); 1829 break; 1830 case NT_FREEBSD_NOINIT_TAG: 1831 /* FreeBSD 'crt does not call init' note */ 1832 obj->crt_no_init = true; 1833 dbg("note crt_no_init"); 1834 break; 1835 } 1836 } 1837 } 1838 1839 static Obj_Entry * 1840 dlcheck(void *handle) 1841 { 1842 Obj_Entry *obj; 1843 1844 TAILQ_FOREACH(obj, &obj_list, next) { 1845 if (obj == (Obj_Entry *)handle) 1846 break; 1847 } 1848 1849 if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) { 1850 _rtld_error("Invalid shared object handle %p", handle); 1851 return (NULL); 1852 } 1853 return (obj); 1854 } 1855 1856 /* 1857 * If the given object is already in the donelist, return true. Otherwise 1858 * add the object to the list and return false. 1859 */ 1860 static bool 1861 donelist_check(DoneList *dlp, const Obj_Entry *obj) 1862 { 1863 unsigned int i; 1864 1865 for (i = 0; i < dlp->num_used; i++) 1866 if (dlp->objs[i] == obj) 1867 return (true); 1868 /* 1869 * Our donelist allocation should always be sufficient. But if 1870 * our threads locking isn't working properly, more shared objects 1871 * could have been loaded since we allocated the list. That should 1872 * never happen, but we'll handle it properly just in case it does. 1873 */ 1874 if (dlp->num_used < dlp->num_alloc) 1875 dlp->objs[dlp->num_used++] = obj; 1876 return (false); 1877 } 1878 1879 /* 1880 * SysV hash function for symbol table lookup. It is a slightly optimized 1881 * version of the hash specified by the System V ABI. 1882 */ 1883 Elf32_Word 1884 elf_hash(const char *name) 1885 { 1886 const unsigned char *p = (const unsigned char *)name; 1887 Elf32_Word h = 0; 1888 1889 while (*p != '\0') { 1890 h = (h << 4) + *p++; 1891 h ^= (h >> 24) & 0xf0; 1892 } 1893 return (h & 0x0fffffff); 1894 } 1895 1896 /* 1897 * The GNU hash function is the Daniel J. Bernstein hash clipped to 32 bits 1898 * unsigned in case it's implemented with a wider type. 1899 */ 1900 static uint32_t 1901 gnu_hash(const char *s) 1902 { 1903 uint32_t h; 1904 unsigned char c; 1905 1906 h = 5381; 1907 for (c = *s; c != '\0'; c = *++s) 1908 h = h * 33 + c; 1909 return (h & 0xffffffff); 1910 } 1911 1912 /* 1913 * Find the library with the given name, and return its full pathname. 1914 * The returned string is dynamically allocated. Generates an error 1915 * message and returns NULL if the library cannot be found. 1916 * 1917 * If the second argument is non-NULL, then it refers to an already- 1918 * loaded shared object, whose library search path will be searched. 1919 * 1920 * If a library is successfully located via LD_LIBRARY_PATH_FDS, its 1921 * descriptor (which is close-on-exec) will be passed out via the third 1922 * argument. 1923 * 1924 * The search order is: 1925 * DT_RPATH in the referencing file _unless_ DT_RUNPATH is present (1) 1926 * DT_RPATH of the main object if DSO without defined DT_RUNPATH (1) 1927 * LD_LIBRARY_PATH 1928 * DT_RUNPATH in the referencing file 1929 * ldconfig hints (if -z nodefaultlib, filter out default library directories 1930 * from list) 1931 * /lib:/usr/lib _unless_ the referencing file is linked with -z nodefaultlib 1932 * 1933 * (1) Handled in digest_dynamic2 - rpath left NULL if runpath defined. 1934 */ 1935 static char * 1936 find_library(const char *xname, const Obj_Entry *refobj, int *fdp) 1937 { 1938 char *pathname, *refobj_path; 1939 const char *name; 1940 bool nodeflib, objgiven; 1941 1942 objgiven = refobj != NULL; 1943 1944 if (libmap_disable || !objgiven || 1945 (name = lm_find(refobj->path, xname)) == NULL) 1946 name = xname; 1947 1948 if (strchr(name, '/') != NULL) { /* Hard coded pathname */ 1949 if (name[0] != '/' && !trust) { 1950 _rtld_error( 1951 "Absolute pathname required for shared object \"%s\"", 1952 name); 1953 return (NULL); 1954 } 1955 return (origin_subst(__DECONST(Obj_Entry *, refobj), 1956 __DECONST(char *, name))); 1957 } 1958 1959 dbg(" Searching for \"%s\"", name); 1960 refobj_path = objgiven ? refobj->path : NULL; 1961 1962 /* 1963 * If refobj->rpath != NULL, then refobj->runpath is NULL. Fall 1964 * back to pre-conforming behaviour if user requested so with 1965 * LD_LIBRARY_PATH_RPATH environment variable and ignore -z 1966 * nodeflib. 1967 */ 1968 if (objgiven && refobj->rpath != NULL && ld_library_path_rpath) { 1969 pathname = search_library_path(name, ld_library_path, 1970 refobj_path, fdp); 1971 if (pathname != NULL) 1972 return (pathname); 1973 if (refobj != NULL) { 1974 pathname = search_library_path(name, refobj->rpath, 1975 refobj_path, fdp); 1976 if (pathname != NULL) 1977 return (pathname); 1978 } 1979 pathname = search_library_pathfds(name, ld_library_dirs, fdp); 1980 if (pathname != NULL) 1981 return (pathname); 1982 pathname = search_library_path(name, gethints(false), 1983 refobj_path, fdp); 1984 if (pathname != NULL) 1985 return (pathname); 1986 pathname = search_library_path(name, ld_standard_library_path, 1987 refobj_path, fdp); 1988 if (pathname != NULL) 1989 return (pathname); 1990 } else { 1991 nodeflib = objgiven ? refobj->z_nodeflib : false; 1992 if (objgiven) { 1993 pathname = search_library_path(name, refobj->rpath, 1994 refobj->path, fdp); 1995 if (pathname != NULL) 1996 return (pathname); 1997 } 1998 if (objgiven && refobj->runpath == NULL && refobj != obj_main) { 1999 pathname = search_library_path(name, obj_main->rpath, 2000 refobj_path, fdp); 2001 if (pathname != NULL) 2002 return (pathname); 2003 } 2004 pathname = search_library_path(name, ld_library_path, 2005 refobj_path, fdp); 2006 if (pathname != NULL) 2007 return (pathname); 2008 if (objgiven) { 2009 pathname = search_library_path(name, refobj->runpath, 2010 refobj_path, fdp); 2011 if (pathname != NULL) 2012 return (pathname); 2013 } 2014 pathname = search_library_pathfds(name, ld_library_dirs, fdp); 2015 if (pathname != NULL) 2016 return (pathname); 2017 pathname = search_library_path(name, gethints(nodeflib), 2018 refobj_path, fdp); 2019 if (pathname != NULL) 2020 return (pathname); 2021 if (objgiven && !nodeflib) { 2022 pathname = search_library_path(name, 2023 ld_standard_library_path, refobj_path, fdp); 2024 if (pathname != NULL) 2025 return (pathname); 2026 } 2027 } 2028 2029 if (objgiven && refobj->path != NULL) { 2030 _rtld_error( 2031 "Shared object \"%s\" not found, required by \"%s\"", 2032 name, basename(refobj->path)); 2033 } else { 2034 _rtld_error("Shared object \"%s\" not found", name); 2035 } 2036 return (NULL); 2037 } 2038 2039 /* 2040 * Given a symbol number in a referencing object, find the corresponding 2041 * definition of the symbol. Returns a pointer to the symbol, or NULL if 2042 * no definition was found. Returns a pointer to the Obj_Entry of the 2043 * defining object via the reference parameter DEFOBJ_OUT. 2044 */ 2045 const Elf_Sym * 2046 find_symdef(unsigned long symnum, const Obj_Entry *refobj, 2047 const Obj_Entry **defobj_out, int flags, SymCache *cache, 2048 RtldLockState *lockstate) 2049 { 2050 const Elf_Sym *ref; 2051 const Elf_Sym *def; 2052 const Obj_Entry *defobj; 2053 const Ver_Entry *ve; 2054 SymLook req; 2055 const char *name; 2056 int res; 2057 2058 /* 2059 * If we have already found this symbol, get the information from 2060 * the cache. 2061 */ 2062 if (symnum >= refobj->dynsymcount) 2063 return (NULL); /* Bad object */ 2064 if (cache != NULL && cache[symnum].sym != NULL) { 2065 *defobj_out = cache[symnum].obj; 2066 return (cache[symnum].sym); 2067 } 2068 2069 ref = refobj->symtab + symnum; 2070 name = refobj->strtab + ref->st_name; 2071 def = NULL; 2072 defobj = NULL; 2073 ve = NULL; 2074 2075 /* 2076 * We don't have to do a full scale lookup if the symbol is local. 2077 * We know it will bind to the instance in this load module; to 2078 * which we already have a pointer (ie ref). By not doing a lookup, 2079 * we not only improve performance, but it also avoids unresolvable 2080 * symbols when local symbols are not in the hash table. This has 2081 * been seen with the ia64 toolchain. 2082 */ 2083 if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) { 2084 if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) { 2085 _rtld_error("%s: Bogus symbol table entry %lu", 2086 refobj->path, symnum); 2087 } 2088 symlook_init(&req, name); 2089 req.flags = flags; 2090 ve = req.ventry = fetch_ventry(refobj, symnum); 2091 req.lockstate = lockstate; 2092 res = symlook_default(&req, refobj); 2093 if (res == 0) { 2094 def = req.sym_out; 2095 defobj = req.defobj_out; 2096 } 2097 } else { 2098 def = ref; 2099 defobj = refobj; 2100 } 2101 2102 /* 2103 * If we found no definition and the reference is weak, treat the 2104 * symbol as having the value zero. 2105 */ 2106 if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) { 2107 def = &sym_zero; 2108 defobj = obj_main; 2109 } 2110 2111 if (def != NULL) { 2112 *defobj_out = defobj; 2113 /* 2114 * Record the information in the cache to avoid subsequent 2115 * lookups. 2116 */ 2117 if (cache != NULL) { 2118 cache[symnum].sym = def; 2119 cache[symnum].obj = defobj; 2120 } 2121 } else { 2122 if (refobj != &obj_rtld) 2123 _rtld_error("%s: Undefined symbol \"%s%s%s\"", 2124 refobj->path, name, ve != NULL ? "@" : "", 2125 ve != NULL ? ve->name : ""); 2126 } 2127 return (def); 2128 } 2129 2130 /* Convert between native byte order and forced little resp. big endian. */ 2131 #define COND_SWAP(n) (is_le ? le32toh(n) : be32toh(n)) 2132 2133 /* 2134 * Return the search path from the ldconfig hints file, reading it if 2135 * necessary. If nostdlib is true, then the default search paths are 2136 * not added to result. 2137 * 2138 * Returns NULL if there are problems with the hints file, 2139 * or if the search path there is empty. 2140 */ 2141 static const char * 2142 gethints(bool nostdlib) 2143 { 2144 static char *filtered_path; 2145 static const char *hints; 2146 static struct elfhints_hdr hdr; 2147 struct fill_search_info_args sargs, hargs; 2148 struct dl_serinfo smeta, hmeta, *SLPinfo, *hintinfo; 2149 struct dl_serpath *SLPpath, *hintpath; 2150 char *p; 2151 struct stat hint_stat; 2152 unsigned int SLPndx, hintndx, fndx, fcount; 2153 int fd; 2154 size_t flen; 2155 uint32_t dl; 2156 uint32_t magic; /* Magic number */ 2157 uint32_t version; /* File version (1) */ 2158 uint32_t strtab; /* Offset of string table in file */ 2159 uint32_t dirlist; /* Offset of directory list in string table */ 2160 uint32_t dirlistlen; /* strlen(dirlist) */ 2161 bool is_le; /* Does the hints file use little endian */ 2162 bool skip; 2163 2164 /* First call, read the hints file */ 2165 if (hints == NULL) { 2166 /* Keep from trying again in case the hints file is bad. */ 2167 hints = ""; 2168 2169 if ((fd = open(ld_elf_hints_path, O_RDONLY | O_CLOEXEC)) == 2170 -1) { 2171 dbg("failed to open hints file \"%s\"", 2172 ld_elf_hints_path); 2173 return (NULL); 2174 } 2175 2176 /* 2177 * Check of hdr.dirlistlen value against type limit 2178 * intends to pacify static analyzers. Further 2179 * paranoia leads to checks that dirlist is fully 2180 * contained in the file range. 2181 */ 2182 if (read(fd, &hdr, sizeof hdr) != sizeof hdr) { 2183 dbg("failed to read %lu bytes from hints file \"%s\"", 2184 (u_long)sizeof hdr, ld_elf_hints_path); 2185 cleanup1: 2186 close(fd); 2187 hdr.dirlistlen = 0; 2188 return (NULL); 2189 } 2190 dbg("host byte-order: %s-endian", 2191 le32toh(1) == 1 ? "little" : "big"); 2192 dbg("hints file byte-order: %s-endian", 2193 hdr.magic == htole32(ELFHINTS_MAGIC) ? "little" : "big"); 2194 is_le = /*htole32(1) == 1 || */ hdr.magic == 2195 htole32(ELFHINTS_MAGIC); 2196 magic = COND_SWAP(hdr.magic); 2197 version = COND_SWAP(hdr.version); 2198 strtab = COND_SWAP(hdr.strtab); 2199 dirlist = COND_SWAP(hdr.dirlist); 2200 dirlistlen = COND_SWAP(hdr.dirlistlen); 2201 if (magic != ELFHINTS_MAGIC) { 2202 dbg("invalid magic number %#08x (expected: %#08x)", 2203 magic, ELFHINTS_MAGIC); 2204 goto cleanup1; 2205 } 2206 if (version != 1) { 2207 dbg("hints file version %d (expected: 1)", version); 2208 goto cleanup1; 2209 } 2210 if (dirlistlen > UINT_MAX / 2) { 2211 dbg("directory list is to long: %d > %d", dirlistlen, 2212 UINT_MAX / 2); 2213 goto cleanup1; 2214 } 2215 if (fstat(fd, &hint_stat) == -1) { 2216 dbg("failed to find length of hints file \"%s\"", 2217 ld_elf_hints_path); 2218 goto cleanup1; 2219 } 2220 dl = strtab; 2221 if (dl + dirlist < dl) { 2222 dbg("invalid string table position %d", dl); 2223 goto cleanup1; 2224 } 2225 dl += dirlist; 2226 if (dl + dirlistlen < dl) { 2227 dbg("invalid directory list offset %d", dirlist); 2228 goto cleanup1; 2229 } 2230 dl += dirlistlen; 2231 if (dl > hint_stat.st_size) { 2232 dbg("hints file \"%s\" is truncated (%d vs. %jd bytes)", 2233 ld_elf_hints_path, dl, 2234 (uintmax_t)hint_stat.st_size); 2235 goto cleanup1; 2236 } 2237 p = xmalloc(dirlistlen + 1); 2238 if (pread(fd, p, dirlistlen + 1, strtab + dirlist) != 2239 (ssize_t)dirlistlen + 1 || p[dirlistlen] != '\0') { 2240 free(p); 2241 dbg( 2242 "failed to read %d bytes starting at %d from hints file \"%s\"", 2243 dirlistlen + 1, strtab + dirlist, 2244 ld_elf_hints_path); 2245 goto cleanup1; 2246 } 2247 hints = p; 2248 close(fd); 2249 } 2250 2251 /* 2252 * If caller agreed to receive list which includes the default 2253 * paths, we are done. Otherwise, if we still did not 2254 * calculated filtered result, do it now. 2255 */ 2256 if (!nostdlib) 2257 return (hints[0] != '\0' ? hints : NULL); 2258 if (filtered_path != NULL) 2259 goto filt_ret; 2260 2261 /* 2262 * Obtain the list of all configured search paths, and the 2263 * list of the default paths. 2264 * 2265 * First estimate the size of the results. 2266 */ 2267 smeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 2268 smeta.dls_cnt = 0; 2269 hmeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 2270 hmeta.dls_cnt = 0; 2271 2272 sargs.request = RTLD_DI_SERINFOSIZE; 2273 sargs.serinfo = &smeta; 2274 hargs.request = RTLD_DI_SERINFOSIZE; 2275 hargs.serinfo = &hmeta; 2276 2277 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 2278 &sargs); 2279 path_enumerate(hints, fill_search_info, NULL, &hargs); 2280 2281 SLPinfo = xmalloc(smeta.dls_size); 2282 hintinfo = xmalloc(hmeta.dls_size); 2283 2284 /* 2285 * Next fetch both sets of paths. 2286 */ 2287 sargs.request = RTLD_DI_SERINFO; 2288 sargs.serinfo = SLPinfo; 2289 sargs.serpath = &SLPinfo->dls_serpath[0]; 2290 sargs.strspace = (char *)&SLPinfo->dls_serpath[smeta.dls_cnt]; 2291 2292 hargs.request = RTLD_DI_SERINFO; 2293 hargs.serinfo = hintinfo; 2294 hargs.serpath = &hintinfo->dls_serpath[0]; 2295 hargs.strspace = (char *)&hintinfo->dls_serpath[hmeta.dls_cnt]; 2296 2297 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 2298 &sargs); 2299 path_enumerate(hints, fill_search_info, NULL, &hargs); 2300 2301 /* 2302 * Now calculate the difference between two sets, by excluding 2303 * standard paths from the full set. 2304 */ 2305 fndx = 0; 2306 fcount = 0; 2307 filtered_path = xmalloc(dirlistlen + 1); 2308 hintpath = &hintinfo->dls_serpath[0]; 2309 for (hintndx = 0; hintndx < hmeta.dls_cnt; hintndx++, hintpath++) { 2310 skip = false; 2311 SLPpath = &SLPinfo->dls_serpath[0]; 2312 /* 2313 * Check each standard path against current. 2314 */ 2315 for (SLPndx = 0; SLPndx < smeta.dls_cnt; SLPndx++, SLPpath++) { 2316 /* matched, skip the path */ 2317 if (!strcmp(hintpath->dls_name, SLPpath->dls_name)) { 2318 skip = true; 2319 break; 2320 } 2321 } 2322 if (skip) 2323 continue; 2324 /* 2325 * Not matched against any standard path, add the path 2326 * to result. Separate consequtive paths with ':'. 2327 */ 2328 if (fcount > 0) { 2329 filtered_path[fndx] = ':'; 2330 fndx++; 2331 } 2332 fcount++; 2333 flen = strlen(hintpath->dls_name); 2334 strncpy((filtered_path + fndx), hintpath->dls_name, flen); 2335 fndx += flen; 2336 } 2337 filtered_path[fndx] = '\0'; 2338 2339 free(SLPinfo); 2340 free(hintinfo); 2341 2342 filt_ret: 2343 return (filtered_path[0] != '\0' ? filtered_path : NULL); 2344 } 2345 2346 static void 2347 init_dag(Obj_Entry *root) 2348 { 2349 const Needed_Entry *needed; 2350 const Objlist_Entry *elm; 2351 DoneList donelist; 2352 2353 if (root->dag_inited) 2354 return; 2355 donelist_init(&donelist, NULL); 2356 2357 /* Root object belongs to own DAG. */ 2358 objlist_push_tail(&root->dldags, root); 2359 objlist_push_tail(&root->dagmembers, root); 2360 donelist_check(&donelist, root); 2361 2362 /* 2363 * Add dependencies of root object to DAG in breadth order 2364 * by exploiting the fact that each new object get added 2365 * to the tail of the dagmembers list. 2366 */ 2367 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2368 for (needed = elm->obj->needed; needed != NULL; 2369 needed = needed->next) { 2370 if (needed->obj == NULL || 2371 donelist_check(&donelist, needed->obj)) 2372 continue; 2373 objlist_push_tail(&needed->obj->dldags, root); 2374 objlist_push_tail(&root->dagmembers, needed->obj); 2375 } 2376 } 2377 root->dag_inited = true; 2378 donelist_free(&donelist); 2379 } 2380 2381 static void 2382 init_marker(Obj_Entry *marker) 2383 { 2384 bzero(marker, sizeof(*marker)); 2385 marker->marker = true; 2386 } 2387 2388 Obj_Entry * 2389 globallist_curr(const Obj_Entry *obj) 2390 { 2391 for (;;) { 2392 if (obj == NULL) 2393 return (NULL); 2394 if (!obj->marker) 2395 return (__DECONST(Obj_Entry *, obj)); 2396 obj = TAILQ_PREV(obj, obj_entry_q, next); 2397 } 2398 } 2399 2400 Obj_Entry * 2401 globallist_next(const Obj_Entry *obj) 2402 { 2403 for (;;) { 2404 obj = TAILQ_NEXT(obj, next); 2405 if (obj == NULL) 2406 return (NULL); 2407 if (!obj->marker) 2408 return (__DECONST(Obj_Entry *, obj)); 2409 } 2410 } 2411 2412 /* Prevent the object from being unmapped while the bind lock is dropped. */ 2413 static void 2414 hold_object(Obj_Entry *obj) 2415 { 2416 obj->holdcount++; 2417 } 2418 2419 static void 2420 unhold_object(Obj_Entry *obj) 2421 { 2422 assert(obj->holdcount > 0); 2423 if (--obj->holdcount == 0 && obj->unholdfree) 2424 release_object(obj); 2425 } 2426 2427 static void 2428 process_z(Obj_Entry *root) 2429 { 2430 const Objlist_Entry *elm; 2431 Obj_Entry *obj; 2432 2433 /* 2434 * Walk over object DAG and process every dependent object 2435 * that is marked as DF_1_NODELETE or DF_1_GLOBAL. They need 2436 * to grow their own DAG. 2437 * 2438 * For DF_1_GLOBAL, DAG is required for symbol lookups in 2439 * symlook_global() to work. 2440 * 2441 * For DF_1_NODELETE, the DAG should have its reference upped. 2442 */ 2443 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2444 obj = elm->obj; 2445 if (obj == NULL) 2446 continue; 2447 if (obj->z_nodelete && !obj->ref_nodel) { 2448 dbg("obj %s -z nodelete", obj->path); 2449 init_dag(obj); 2450 ref_dag(obj); 2451 obj->ref_nodel = true; 2452 } 2453 if (obj->z_global && objlist_find(&list_global, obj) == NULL) { 2454 dbg("obj %s -z global", obj->path); 2455 objlist_push_tail(&list_global, obj); 2456 init_dag(obj); 2457 } 2458 } 2459 } 2460 2461 static void 2462 parse_rtld_phdr(Obj_Entry *obj) 2463 { 2464 const Elf_Phdr *ph; 2465 Elf_Addr note_start, note_end; 2466 bool first_seg; 2467 2468 first_seg = true; 2469 obj->stack_flags = PF_X | PF_R | PF_W; 2470 for (ph = obj->phdr; ph < obj->phdr + obj->phnum; ph++) { 2471 switch (ph->p_type) { 2472 case PT_LOAD: 2473 if (first_seg) { 2474 obj->vaddrbase = rtld_trunc_page(ph->p_vaddr); 2475 first_seg = false; 2476 } 2477 obj->mapsize = rtld_round_page(ph->p_vaddr + 2478 ph->p_memsz) - obj->vaddrbase; 2479 break; 2480 case PT_GNU_STACK: 2481 obj->stack_flags = ph->p_flags; 2482 break; 2483 case PT_NOTE: 2484 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; 2485 note_end = note_start + ph->p_filesz; 2486 digest_notes(obj, note_start, note_end); 2487 break; 2488 } 2489 } 2490 } 2491 2492 /* 2493 * Initialize the dynamic linker. The argument is the address at which 2494 * the dynamic linker has been mapped into memory. The primary task of 2495 * this function is to relocate the dynamic linker. 2496 */ 2497 static void 2498 init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info) 2499 { 2500 Obj_Entry objtmp; /* Temporary rtld object */ 2501 const Elf_Ehdr *ehdr; 2502 const Elf_Dyn *dyn_rpath; 2503 const Elf_Dyn *dyn_soname; 2504 const Elf_Dyn *dyn_runpath; 2505 2506 /* 2507 * Conjure up an Obj_Entry structure for the dynamic linker. 2508 * 2509 * The "path" member can't be initialized yet because string constants 2510 * cannot yet be accessed. Below we will set it correctly. 2511 */ 2512 memset(&objtmp, 0, sizeof(objtmp)); 2513 objtmp.path = NULL; 2514 objtmp.rtld = true; 2515 objtmp.mapbase = mapbase; 2516 objtmp.relocbase = mapbase; 2517 2518 objtmp.dynamic = rtld_dynamic(&objtmp); 2519 digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname, &dyn_runpath); 2520 assert(objtmp.needed == NULL); 2521 assert(!objtmp.textrel); 2522 /* 2523 * Temporarily put the dynamic linker entry into the object list, so 2524 * that symbols can be found. 2525 */ 2526 relocate_objects(&objtmp, true, &objtmp, 0, NULL); 2527 2528 ehdr = (Elf_Ehdr *)mapbase; 2529 objtmp.phdr = (Elf_Phdr *)((char *)mapbase + ehdr->e_phoff); 2530 objtmp.phnum = ehdr->e_phnum; 2531 2532 /* Initialize the object list. */ 2533 TAILQ_INIT(&obj_list); 2534 2535 /* Now that non-local variables can be accesses, copy out obj_rtld. */ 2536 memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld)); 2537 2538 /* The page size is required by the dynamic memory allocator. */ 2539 init_pagesizes(aux_info); 2540 2541 if (aux_info[AT_OSRELDATE] != NULL) 2542 osreldate = aux_info[AT_OSRELDATE]->a_un.a_val; 2543 2544 digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname, dyn_runpath); 2545 2546 /* Replace the path with a dynamically allocated copy. */ 2547 obj_rtld.path = xstrdup(ld_path_rtld); 2548 2549 parse_rtld_phdr(&obj_rtld); 2550 if (obj_enforce_relro(&obj_rtld) == -1) 2551 rtld_die(); 2552 2553 r_debug.r_version = R_DEBUG_VERSION; 2554 r_debug.r_brk = r_debug_state; 2555 r_debug.r_state = RT_CONSISTENT; 2556 r_debug.r_ldbase = obj_rtld.relocbase; 2557 } 2558 2559 /* 2560 * Retrieve the array of supported page sizes. The kernel provides the page 2561 * sizes in increasing order. 2562 */ 2563 static void 2564 init_pagesizes(Elf_Auxinfo **aux_info) 2565 { 2566 static size_t psa[MAXPAGESIZES]; 2567 int mib[2]; 2568 size_t len, size; 2569 2570 if (aux_info[AT_PAGESIZES] != NULL && 2571 aux_info[AT_PAGESIZESLEN] != NULL) { 2572 size = aux_info[AT_PAGESIZESLEN]->a_un.a_val; 2573 pagesizes = aux_info[AT_PAGESIZES]->a_un.a_ptr; 2574 } else { 2575 len = 2; 2576 if (sysctlnametomib("hw.pagesizes", mib, &len) == 0) 2577 size = sizeof(psa); 2578 else { 2579 /* As a fallback, retrieve the base page size. */ 2580 size = sizeof(psa[0]); 2581 if (aux_info[AT_PAGESZ] != NULL) { 2582 psa[0] = aux_info[AT_PAGESZ]->a_un.a_val; 2583 goto psa_filled; 2584 } else { 2585 mib[0] = CTL_HW; 2586 mib[1] = HW_PAGESIZE; 2587 len = 2; 2588 } 2589 } 2590 if (sysctl(mib, len, psa, &size, NULL, 0) == -1) { 2591 _rtld_error("sysctl for hw.pagesize(s) failed"); 2592 rtld_die(); 2593 } 2594 psa_filled: 2595 pagesizes = psa; 2596 } 2597 npagesizes = size / sizeof(pagesizes[0]); 2598 /* Discard any invalid entries at the end of the array. */ 2599 while (npagesizes > 0 && pagesizes[npagesizes - 1] == 0) 2600 npagesizes--; 2601 2602 page_size = pagesizes[0]; 2603 } 2604 2605 /* 2606 * Add the init functions from a needed object list (and its recursive 2607 * needed objects) to "list". This is not used directly; it is a helper 2608 * function for initlist_add_objects(). The write lock must be held 2609 * when this function is called. 2610 */ 2611 static void 2612 initlist_add_neededs(Needed_Entry *needed, Objlist *list, Objlist *iflist) 2613 { 2614 /* Recursively process the successor needed objects. */ 2615 if (needed->next != NULL) 2616 initlist_add_neededs(needed->next, list, iflist); 2617 2618 /* Process the current needed object. */ 2619 if (needed->obj != NULL) 2620 initlist_add_objects(needed->obj, needed->obj, list, iflist); 2621 } 2622 2623 /* 2624 * Scan all of the DAGs rooted in the range of objects from "obj" to 2625 * "tail" and add their init functions to "list". This recurses over 2626 * the DAGs and ensure the proper init ordering such that each object's 2627 * needed libraries are initialized before the object itself. At the 2628 * same time, this function adds the objects to the global finalization 2629 * list "list_fini" in the opposite order. The write lock must be 2630 * held when this function is called. 2631 */ 2632 static void 2633 initlist_for_loaded_obj(Obj_Entry *obj, Obj_Entry *tail, Objlist *list) 2634 { 2635 Objlist iflist; /* initfirst objs and their needed */ 2636 Objlist_Entry *tmp; 2637 2638 objlist_init(&iflist); 2639 initlist_add_objects(obj, tail, list, &iflist); 2640 2641 STAILQ_FOREACH(tmp, &iflist, link) { 2642 Obj_Entry *tobj = tmp->obj; 2643 2644 if ((tobj->fini != 0 || tobj->fini_array != NULL) && 2645 !tobj->on_fini_list) { 2646 objlist_push_tail(&list_fini, tobj); 2647 tobj->on_fini_list = true; 2648 } 2649 } 2650 2651 /* 2652 * This might result in the same object appearing more 2653 * than once on the init list. objlist_call_init() 2654 * uses obj->init_scanned to avoid dup calls. 2655 */ 2656 STAILQ_REVERSE(&iflist, Struct_Objlist_Entry, link); 2657 STAILQ_FOREACH(tmp, &iflist, link) 2658 objlist_push_head(list, tmp->obj); 2659 2660 objlist_clear(&iflist); 2661 } 2662 2663 static void 2664 initlist_add_objects(Obj_Entry *obj, Obj_Entry *tail, Objlist *list, 2665 Objlist *iflist) 2666 { 2667 Obj_Entry *nobj; 2668 2669 if (obj->init_done) 2670 return; 2671 2672 if (obj->z_initfirst || list == NULL) { 2673 /* 2674 * Ignore obj->init_scanned. The object might indeed 2675 * already be on the init list, but due to being 2676 * needed by an initfirst object, we must put it at 2677 * the head of the init list. obj->init_done protects 2678 * against double-initialization. 2679 */ 2680 if (obj->needed != NULL) 2681 initlist_add_neededs(obj->needed, NULL, iflist); 2682 if (obj->needed_filtees != NULL) 2683 initlist_add_neededs(obj->needed_filtees, NULL, 2684 iflist); 2685 if (obj->needed_aux_filtees != NULL) 2686 initlist_add_neededs(obj->needed_aux_filtees, 2687 NULL, iflist); 2688 objlist_push_tail(iflist, obj); 2689 2690 /* Recursively process the successor objects. */ 2691 nobj = globallist_next(obj); 2692 if (nobj != NULL && obj != tail) 2693 initlist_add_objects(nobj, tail, list, iflist); 2694 } else { 2695 if (obj->init_scanned) 2696 return; 2697 obj->init_scanned = true; 2698 2699 /* Recursively process the successor objects. */ 2700 nobj = globallist_next(obj); 2701 if (nobj != NULL && obj != tail) 2702 initlist_add_objects(nobj, tail, list, iflist); 2703 2704 /* Recursively process the needed objects. */ 2705 if (obj->needed != NULL) 2706 initlist_add_neededs(obj->needed, list, iflist); 2707 if (obj->needed_filtees != NULL) 2708 initlist_add_neededs(obj->needed_filtees, list, 2709 iflist); 2710 if (obj->needed_aux_filtees != NULL) 2711 initlist_add_neededs(obj->needed_aux_filtees, list, 2712 iflist); 2713 2714 /* Add the object to the init list. */ 2715 objlist_push_tail(list, obj); 2716 2717 /* 2718 * Add the object to the global fini list in the 2719 * reverse order. 2720 */ 2721 if ((obj->fini != 0 || obj->fini_array != NULL) && 2722 !obj->on_fini_list) { 2723 objlist_push_head(&list_fini, obj); 2724 obj->on_fini_list = true; 2725 } 2726 } 2727 } 2728 2729 static void 2730 free_needed_filtees(Needed_Entry *n, RtldLockState *lockstate) 2731 { 2732 Needed_Entry *needed, *needed1; 2733 2734 for (needed = n; needed != NULL; needed = needed->next) { 2735 if (needed->obj != NULL) { 2736 dlclose_locked(needed->obj, lockstate); 2737 needed->obj = NULL; 2738 } 2739 } 2740 for (needed = n; needed != NULL; needed = needed1) { 2741 needed1 = needed->next; 2742 free(needed); 2743 } 2744 } 2745 2746 static void 2747 unload_filtees(Obj_Entry *obj, RtldLockState *lockstate) 2748 { 2749 free_needed_filtees(obj->needed_filtees, lockstate); 2750 obj->needed_filtees = NULL; 2751 free_needed_filtees(obj->needed_aux_filtees, lockstate); 2752 obj->needed_aux_filtees = NULL; 2753 obj->filtees_loaded = false; 2754 } 2755 2756 static void 2757 load_filtee1(Obj_Entry *obj, Needed_Entry *needed, int flags, 2758 RtldLockState *lockstate) 2759 { 2760 for (; needed != NULL; needed = needed->next) { 2761 needed->obj = dlopen_object(obj->strtab + needed->name, -1, obj, 2762 flags, ((ld_loadfltr || obj->z_loadfltr) ? RTLD_NOW : 2763 RTLD_LAZY) | RTLD_LOCAL, lockstate); 2764 } 2765 } 2766 2767 static void 2768 load_filtees(Obj_Entry *obj, int flags, RtldLockState *lockstate) 2769 { 2770 if (obj->filtees_loaded || obj->filtees_loading) 2771 return; 2772 lock_restart_for_upgrade(lockstate); 2773 obj->filtees_loading = true; 2774 load_filtee1(obj, obj->needed_filtees, flags, lockstate); 2775 load_filtee1(obj, obj->needed_aux_filtees, flags, lockstate); 2776 obj->filtees_loaded = true; 2777 obj->filtees_loading = false; 2778 } 2779 2780 static int 2781 process_needed(Obj_Entry *obj, Needed_Entry *needed, int flags) 2782 { 2783 Obj_Entry *obj1; 2784 2785 for (; needed != NULL; needed = needed->next) { 2786 obj1 = needed->obj = load_object(obj->strtab + needed->name, -1, 2787 obj, flags & ~RTLD_LO_NOLOAD); 2788 if (obj1 == NULL && !ld_tracing && 2789 (flags & RTLD_LO_FILTEES) == 0) 2790 return (-1); 2791 } 2792 return (0); 2793 } 2794 2795 /* 2796 * Given a shared object, traverse its list of needed objects, and load 2797 * each of them. Returns 0 on success. Generates an error message and 2798 * returns -1 on failure. 2799 */ 2800 static int 2801 load_needed_objects(Obj_Entry *first, int flags) 2802 { 2803 Obj_Entry *obj; 2804 2805 for (obj = first; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 2806 if (obj->marker) 2807 continue; 2808 if (process_needed(obj, obj->needed, flags) == -1) 2809 return (-1); 2810 } 2811 return (0); 2812 } 2813 2814 static int 2815 load_preload_objects(const char *penv, bool isfd) 2816 { 2817 Obj_Entry *obj; 2818 const char *name; 2819 size_t len; 2820 char savech, *p, *psave; 2821 int fd; 2822 static const char delim[] = " \t:;"; 2823 2824 if (penv == NULL) 2825 return (0); 2826 2827 p = psave = xstrdup(penv); 2828 p += strspn(p, delim); 2829 while (*p != '\0') { 2830 len = strcspn(p, delim); 2831 2832 savech = p[len]; 2833 p[len] = '\0'; 2834 if (isfd) { 2835 name = NULL; 2836 fd = parse_integer(p); 2837 if (fd == -1) { 2838 free(psave); 2839 return (-1); 2840 } 2841 } else { 2842 name = p; 2843 fd = -1; 2844 } 2845 2846 obj = load_object(name, fd, NULL, 0); 2847 if (obj == NULL) { 2848 free(psave); 2849 return (-1); /* XXX - cleanup */ 2850 } 2851 obj->z_interpose = true; 2852 p[len] = savech; 2853 p += len; 2854 p += strspn(p, delim); 2855 } 2856 LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL); 2857 2858 free(psave); 2859 return (0); 2860 } 2861 2862 static const char * 2863 printable_path(const char *path) 2864 { 2865 return (path == NULL ? "<unknown>" : path); 2866 } 2867 2868 /* 2869 * Load a shared object into memory, if it is not already loaded. The 2870 * object may be specified by name or by user-supplied file descriptor 2871 * fd_u. In the later case, the fd_u descriptor is not closed, but its 2872 * duplicate is. 2873 * 2874 * Returns a pointer to the Obj_Entry for the object. Returns NULL 2875 * on failure. 2876 */ 2877 static Obj_Entry * 2878 load_object(const char *name, int fd_u, const Obj_Entry *refobj, int flags) 2879 { 2880 Obj_Entry *obj; 2881 int fd; 2882 struct stat sb; 2883 char *path; 2884 2885 fd = -1; 2886 if (name != NULL) { 2887 TAILQ_FOREACH(obj, &obj_list, next) { 2888 if (obj->marker || obj->doomed) 2889 continue; 2890 if (object_match_name(obj, name)) 2891 return (obj); 2892 } 2893 2894 path = find_library(name, refobj, &fd); 2895 if (path == NULL) 2896 return (NULL); 2897 } else 2898 path = NULL; 2899 2900 if (fd >= 0) { 2901 /* 2902 * search_library_pathfds() opens a fresh file descriptor for 2903 * the library, so there is no need to dup(). 2904 */ 2905 } else if (fd_u == -1) { 2906 /* 2907 * If we didn't find a match by pathname, or the name is not 2908 * supplied, open the file and check again by device and inode. 2909 * This avoids false mismatches caused by multiple links or ".." 2910 * in pathnames. 2911 * 2912 * To avoid a race, we open the file and use fstat() rather than 2913 * using stat(). 2914 */ 2915 if ((fd = open(path, O_RDONLY | O_CLOEXEC | O_VERIFY)) == -1) { 2916 fd = try_fds_open(path, ld_library_dirs); 2917 if (fd == -1) { 2918 _rtld_error("Cannot open \"%s\"", path); 2919 free(path); 2920 return (NULL); 2921 } 2922 } 2923 } else { 2924 fd = fcntl(fd_u, F_DUPFD_CLOEXEC, 0); 2925 if (fd == -1) { 2926 _rtld_error("Cannot dup fd"); 2927 free(path); 2928 return (NULL); 2929 } 2930 } 2931 if (fstat(fd, &sb) == -1) { 2932 _rtld_error("Cannot fstat \"%s\"", printable_path(path)); 2933 close(fd); 2934 free(path); 2935 return (NULL); 2936 } 2937 TAILQ_FOREACH(obj, &obj_list, next) { 2938 if (obj->marker || obj->doomed) 2939 continue; 2940 if (obj->ino == sb.st_ino && obj->dev == sb.st_dev) 2941 break; 2942 } 2943 if (obj != NULL) { 2944 if (name != NULL) 2945 object_add_name(obj, name); 2946 free(path); 2947 close(fd); 2948 return (obj); 2949 } 2950 if (flags & RTLD_LO_NOLOAD) { 2951 free(path); 2952 close(fd); 2953 return (NULL); 2954 } 2955 2956 /* First use of this object, so we must map it in */ 2957 obj = do_load_object(fd, name, path, &sb, flags); 2958 if (obj == NULL) 2959 free(path); 2960 close(fd); 2961 2962 return (obj); 2963 } 2964 2965 static Obj_Entry * 2966 do_load_object(int fd, const char *name, char *path, struct stat *sbp, 2967 int flags) 2968 { 2969 Obj_Entry *obj; 2970 struct statfs fs; 2971 2972 /* 2973 * First, make sure that environment variables haven't been 2974 * used to circumvent the noexec flag on a filesystem. 2975 * We ignore fstatfs(2) failures, since fd might reference 2976 * not a file, e.g. shmfd. 2977 */ 2978 if (dangerous_ld_env && fstatfs(fd, &fs) == 0 && 2979 (fs.f_flags & MNT_NOEXEC) != 0) { 2980 _rtld_error("Cannot execute objects on %s", fs.f_mntonname); 2981 return (NULL); 2982 } 2983 2984 dbg("loading \"%s\"", printable_path(path)); 2985 obj = map_object(fd, printable_path(path), sbp, false); 2986 if (obj == NULL) 2987 return (NULL); 2988 2989 /* 2990 * If DT_SONAME is present in the object, digest_dynamic2 already 2991 * added it to the object names. 2992 */ 2993 if (name != NULL) 2994 object_add_name(obj, name); 2995 obj->path = path; 2996 if (!digest_dynamic(obj, 0)) 2997 goto errp; 2998 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", obj->path, 2999 obj->valid_hash_sysv, obj->valid_hash_gnu, obj->dynsymcount); 3000 if (obj->z_pie && (flags & RTLD_LO_TRACE) == 0) { 3001 dbg("refusing to load PIE executable \"%s\"", obj->path); 3002 _rtld_error("Cannot load PIE binary %s as DSO", obj->path); 3003 goto errp; 3004 } 3005 if (obj->z_noopen && 3006 (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) == RTLD_LO_DLOPEN) { 3007 dbg("refusing to load non-loadable \"%s\"", obj->path); 3008 _rtld_error("Cannot dlopen non-loadable %s", obj->path); 3009 goto errp; 3010 } 3011 3012 obj->dlopened = (flags & RTLD_LO_DLOPEN) != 0; 3013 TAILQ_INSERT_TAIL(&obj_list, obj, next); 3014 obj_count++; 3015 obj_loads++; 3016 linkmap_add(obj); /* for GDB & dlinfo() */ 3017 max_stack_flags |= obj->stack_flags; 3018 3019 dbg(" %p .. %p: %s", obj->mapbase, obj->mapbase + obj->mapsize - 1, 3020 obj->path); 3021 if (obj->textrel) 3022 dbg(" WARNING: %s has impure text", obj->path); 3023 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 3024 obj->path); 3025 3026 return (obj); 3027 3028 errp: 3029 munmap(obj->mapbase, obj->mapsize); 3030 obj->path = NULL; /* obj->path is owned and freed by caller */ 3031 obj_free(obj); 3032 return (NULL); 3033 } 3034 3035 static int 3036 load_kpreload(const void *addr) 3037 { 3038 Obj_Entry *obj; 3039 const Elf_Ehdr *ehdr; 3040 const Elf_Phdr *phdr, *phlimit, *phdyn, *seg0, *segn; 3041 static const char kname[] = "[vdso]"; 3042 3043 ehdr = addr; 3044 if (!check_elf_headers(ehdr, "kpreload")) 3045 return (-1); 3046 obj = obj_new(); 3047 phdr = (const Elf_Phdr *)((const char *)addr + ehdr->e_phoff); 3048 obj->phdr = phdr; 3049 obj->phnum = ehdr->e_phnum; 3050 phlimit = phdr + ehdr->e_phnum; 3051 seg0 = segn = NULL; 3052 3053 for (; phdr < phlimit; phdr++) { 3054 switch (phdr->p_type) { 3055 case PT_DYNAMIC: 3056 phdyn = phdr; 3057 break; 3058 case PT_GNU_STACK: 3059 /* Absense of PT_GNU_STACK implies stack_flags == 0. */ 3060 obj->stack_flags = phdr->p_flags; 3061 break; 3062 case PT_LOAD: 3063 if (seg0 == NULL || seg0->p_vaddr > phdr->p_vaddr) 3064 seg0 = phdr; 3065 if (segn == NULL || 3066 segn->p_vaddr + segn->p_memsz < 3067 phdr->p_vaddr + phdr->p_memsz) 3068 segn = phdr; 3069 break; 3070 } 3071 } 3072 3073 obj->mapbase = __DECONST(caddr_t, addr); 3074 obj->mapsize = segn->p_vaddr + segn->p_memsz; 3075 obj->vaddrbase = 0; 3076 obj->relocbase = obj->mapbase; 3077 3078 object_add_name(obj, kname); 3079 obj->path = xstrdup(kname); 3080 obj->dynamic = (const Elf_Dyn *)(obj->relocbase + phdyn->p_vaddr); 3081 3082 if (!digest_dynamic(obj, 0)) { 3083 obj_free(obj); 3084 return (-1); 3085 } 3086 3087 /* 3088 * We assume that kernel-preloaded object does not need 3089 * relocation. It is currently written into read-only page, 3090 * handling relocations would mean we need to allocate at 3091 * least one additional page per AS. 3092 */ 3093 dbg("%s mapbase %p phdrs %p PT_LOAD phdr %p vaddr %p dynamic %p", 3094 obj->path, obj->mapbase, obj->phdr, seg0, 3095 obj->relocbase + seg0->p_vaddr, obj->dynamic); 3096 3097 TAILQ_INSERT_TAIL(&obj_list, obj, next); 3098 obj_count++; 3099 obj_loads++; 3100 linkmap_add(obj); /* for GDB & dlinfo() */ 3101 max_stack_flags |= obj->stack_flags; 3102 3103 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 3104 obj->path); 3105 return (0); 3106 } 3107 3108 Obj_Entry * 3109 obj_from_addr(const void *addr) 3110 { 3111 Obj_Entry *obj; 3112 3113 TAILQ_FOREACH(obj, &obj_list, next) { 3114 if (obj->marker) 3115 continue; 3116 if (addr < (void *)obj->mapbase) 3117 continue; 3118 if (addr < (void *)(obj->mapbase + obj->mapsize)) 3119 return obj; 3120 } 3121 return (NULL); 3122 } 3123 3124 static void 3125 preinit_main(void) 3126 { 3127 uintptr_t *preinit_addr; 3128 int index; 3129 3130 preinit_addr = obj_main->preinit_array; 3131 if (preinit_addr == NULL) 3132 return; 3133 3134 for (index = 0; index < obj_main->preinit_array_num; index++) { 3135 if (preinit_addr[index] != 0 && preinit_addr[index] != 1) { 3136 dbg("calling preinit function for %s at %p", 3137 obj_main->path, (void *)preinit_addr[index]); 3138 LD_UTRACE(UTRACE_INIT_CALL, obj_main, 3139 (void *)preinit_addr[index], 0, 0, obj_main->path); 3140 call_init_pointer(obj_main, preinit_addr[index]); 3141 } 3142 } 3143 } 3144 3145 /* 3146 * Call the finalization functions for each of the objects in "list" 3147 * belonging to the DAG of "root" and referenced once. If NULL "root" 3148 * is specified, every finalization function will be called regardless 3149 * of the reference count and the list elements won't be freed. All of 3150 * the objects are expected to have non-NULL fini functions. 3151 */ 3152 static void 3153 objlist_call_fini(Objlist *list, Obj_Entry *root, RtldLockState *lockstate) 3154 { 3155 Objlist_Entry *elm; 3156 struct dlerror_save *saved_msg; 3157 uintptr_t *fini_addr; 3158 int index; 3159 3160 assert(root == NULL || root->refcount == 1); 3161 3162 if (root != NULL) 3163 root->doomed = true; 3164 3165 /* 3166 * Preserve the current error message since a fini function might 3167 * call into the dynamic linker and overwrite it. 3168 */ 3169 saved_msg = errmsg_save(); 3170 do { 3171 STAILQ_FOREACH(elm, list, link) { 3172 if (root != NULL && 3173 (elm->obj->refcount != 1 || 3174 objlist_find(&root->dagmembers, elm->obj) == 3175 NULL)) 3176 continue; 3177 /* Remove object from fini list to prevent recursive 3178 * invocation. */ 3179 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 3180 /* Ensure that new references cannot be acquired. */ 3181 elm->obj->doomed = true; 3182 3183 hold_object(elm->obj); 3184 lock_release(rtld_bind_lock, lockstate); 3185 /* 3186 * It is legal to have both DT_FINI and DT_FINI_ARRAY 3187 * defined. When this happens, DT_FINI_ARRAY is 3188 * processed first. 3189 */ 3190 fini_addr = elm->obj->fini_array; 3191 if (fini_addr != NULL && elm->obj->fini_array_num > 0) { 3192 for (index = elm->obj->fini_array_num - 1; 3193 index >= 0; index--) { 3194 if (fini_addr[index] != 0 && 3195 fini_addr[index] != 1 && 3196 fini_addr[index] != (Elf_Addr)-1) { 3197 dbg("calling fini function for %s at %p", 3198 elm->obj->path, 3199 (void *)fini_addr[index]); 3200 LD_UTRACE(UTRACE_FINI_CALL, 3201 elm->obj, 3202 (void *)fini_addr[index], 0, 3203 0, elm->obj->path); 3204 call_initfini_pointer(elm->obj, 3205 fini_addr[index]); 3206 } 3207 } 3208 } 3209 if (elm->obj->fini != 0) { 3210 dbg("calling fini function for %s at %p", 3211 elm->obj->path, (void *)elm->obj->fini); 3212 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, 3213 (void *)elm->obj->fini, 0, 0, 3214 elm->obj->path); 3215 call_initfini_pointer(elm->obj, elm->obj->fini); 3216 } 3217 wlock_acquire(rtld_bind_lock, lockstate); 3218 unhold_object(elm->obj); 3219 /* No need to free anything if process is going down. */ 3220 if (root != NULL) 3221 free(elm); 3222 /* 3223 * We must restart the list traversal after every fini 3224 * call because a dlclose() call from the fini function 3225 * or from another thread might have modified the 3226 * reference counts. 3227 */ 3228 break; 3229 } 3230 } while (elm != NULL); 3231 errmsg_restore(saved_msg); 3232 } 3233 3234 /* 3235 * Call the initialization functions for each of the objects in 3236 * "list". All of the objects are expected to have non-NULL init 3237 * functions. 3238 */ 3239 static void 3240 objlist_call_init(Objlist *list, RtldLockState *lockstate) 3241 { 3242 Objlist_Entry *elm; 3243 Obj_Entry *obj; 3244 struct dlerror_save *saved_msg; 3245 uintptr_t *init_addr; 3246 void (*reg)(void (*)(void)); 3247 int index; 3248 3249 /* 3250 * Clean init_scanned flag so that objects can be rechecked and 3251 * possibly initialized earlier if any of vectors called below 3252 * cause the change by using dlopen. 3253 */ 3254 TAILQ_FOREACH(obj, &obj_list, next) { 3255 if (obj->marker) 3256 continue; 3257 obj->init_scanned = false; 3258 } 3259 3260 /* 3261 * Preserve the current error message since an init function might 3262 * call into the dynamic linker and overwrite it. 3263 */ 3264 saved_msg = errmsg_save(); 3265 STAILQ_FOREACH(elm, list, link) { 3266 if (elm->obj->init_done) /* Initialized early. */ 3267 continue; 3268 /* 3269 * Race: other thread might try to use this object before 3270 * current one completes the initialization. Not much can be 3271 * done here without better locking. 3272 */ 3273 elm->obj->init_done = true; 3274 hold_object(elm->obj); 3275 reg = NULL; 3276 if (elm->obj == obj_main && obj_main->crt_no_init) { 3277 reg = (void (*)(void (*)(void))) 3278 get_program_var_addr("__libc_atexit", lockstate); 3279 } 3280 lock_release(rtld_bind_lock, lockstate); 3281 if (reg != NULL) { 3282 reg(rtld_exit); 3283 rtld_exit_ptr = rtld_nop_exit; 3284 } 3285 3286 /* 3287 * It is legal to have both DT_INIT and DT_INIT_ARRAY defined. 3288 * When this happens, DT_INIT is processed first. 3289 */ 3290 if (elm->obj->init != 0) { 3291 dbg("calling init function for %s at %p", 3292 elm->obj->path, (void *)elm->obj->init); 3293 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, 3294 (void *)elm->obj->init, 0, 0, elm->obj->path); 3295 call_init_pointer(elm->obj, elm->obj->init); 3296 } 3297 init_addr = elm->obj->init_array; 3298 if (init_addr != NULL) { 3299 for (index = 0; index < elm->obj->init_array_num; 3300 index++) { 3301 if (init_addr[index] != 0 && 3302 init_addr[index] != 1 && 3303 init_addr[index] != (Elf_Addr)-1) { 3304 dbg("calling init function for %s at %p", 3305 elm->obj->path, 3306 (void *)init_addr[index]); 3307 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, 3308 (void *)init_addr[index], 0, 0, 3309 elm->obj->path); 3310 call_init_pointer(elm->obj, 3311 init_addr[index]); 3312 } 3313 } 3314 } 3315 wlock_acquire(rtld_bind_lock, lockstate); 3316 unhold_object(elm->obj); 3317 } 3318 errmsg_restore(saved_msg); 3319 } 3320 3321 static void 3322 objlist_clear(Objlist *list) 3323 { 3324 Objlist_Entry *elm; 3325 3326 while (!STAILQ_EMPTY(list)) { 3327 elm = STAILQ_FIRST(list); 3328 STAILQ_REMOVE_HEAD(list, link); 3329 free(elm); 3330 } 3331 } 3332 3333 static Objlist_Entry * 3334 objlist_find(Objlist *list, const Obj_Entry *obj) 3335 { 3336 Objlist_Entry *elm; 3337 3338 STAILQ_FOREACH(elm, list, link) 3339 if (elm->obj == obj) 3340 return elm; 3341 return (NULL); 3342 } 3343 3344 static void 3345 objlist_init(Objlist *list) 3346 { 3347 STAILQ_INIT(list); 3348 } 3349 3350 static void 3351 objlist_push_head(Objlist *list, Obj_Entry *obj) 3352 { 3353 Objlist_Entry *elm; 3354 3355 elm = NEW(Objlist_Entry); 3356 elm->obj = obj; 3357 STAILQ_INSERT_HEAD(list, elm, link); 3358 } 3359 3360 static void 3361 objlist_push_tail(Objlist *list, Obj_Entry *obj) 3362 { 3363 Objlist_Entry *elm; 3364 3365 elm = NEW(Objlist_Entry); 3366 elm->obj = obj; 3367 STAILQ_INSERT_TAIL(list, elm, link); 3368 } 3369 3370 static void 3371 objlist_put_after(Objlist *list, Obj_Entry *listobj, Obj_Entry *obj) 3372 { 3373 Objlist_Entry *elm, *listelm; 3374 3375 STAILQ_FOREACH(listelm, list, link) { 3376 if (listelm->obj == listobj) 3377 break; 3378 } 3379 elm = NEW(Objlist_Entry); 3380 elm->obj = obj; 3381 if (listelm != NULL) 3382 STAILQ_INSERT_AFTER(list, listelm, elm, link); 3383 else 3384 STAILQ_INSERT_TAIL(list, elm, link); 3385 } 3386 3387 static void 3388 objlist_remove(Objlist *list, Obj_Entry *obj) 3389 { 3390 Objlist_Entry *elm; 3391 3392 if ((elm = objlist_find(list, obj)) != NULL) { 3393 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 3394 free(elm); 3395 } 3396 } 3397 3398 /* 3399 * Relocate dag rooted in the specified object. 3400 * Returns 0 on success, or -1 on failure. 3401 */ 3402 3403 static int 3404 relocate_object_dag(Obj_Entry *root, bool bind_now, Obj_Entry *rtldobj, 3405 int flags, RtldLockState *lockstate) 3406 { 3407 Objlist_Entry *elm; 3408 int error; 3409 3410 error = 0; 3411 STAILQ_FOREACH(elm, &root->dagmembers, link) { 3412 error = relocate_object(elm->obj, bind_now, rtldobj, flags, 3413 lockstate); 3414 if (error == -1) 3415 break; 3416 } 3417 return (error); 3418 } 3419 3420 /* 3421 * Prepare for, or clean after, relocating an object marked with 3422 * DT_TEXTREL or DF_TEXTREL. Before relocating, all read-only 3423 * segments are remapped read-write. After relocations are done, the 3424 * segment's permissions are returned back to the modes specified in 3425 * the phdrs. If any relocation happened, or always for wired 3426 * program, COW is triggered. 3427 */ 3428 static int 3429 reloc_textrel_prot(Obj_Entry *obj, bool before) 3430 { 3431 const Elf_Phdr *ph; 3432 void *base; 3433 size_t sz; 3434 int prot; 3435 3436 for (ph = obj->phdr; ph < obj->phdr + obj->phnum; ph++) { 3437 if (ph->p_type != PT_LOAD || (ph->p_flags & PF_W) != 0) 3438 continue; 3439 base = obj->relocbase + rtld_trunc_page(ph->p_vaddr); 3440 sz = rtld_round_page(ph->p_vaddr + ph->p_filesz) - 3441 rtld_trunc_page(ph->p_vaddr); 3442 prot = before ? (PROT_READ | PROT_WRITE) : 3443 convert_prot(ph->p_flags); 3444 if (mprotect(base, sz, prot) == -1) { 3445 _rtld_error("%s: Cannot write-%sable text segment: %s", 3446 obj->path, before ? "en" : "dis", 3447 rtld_strerror(errno)); 3448 return (-1); 3449 } 3450 } 3451 return (0); 3452 } 3453 3454 /* Process RELR relative relocations. */ 3455 static void 3456 reloc_relr(Obj_Entry *obj) 3457 { 3458 const Elf_Relr *relr, *relrlim; 3459 Elf_Addr *where; 3460 3461 relrlim = (const Elf_Relr *)((const char *)obj->relr + obj->relrsize); 3462 for (relr = obj->relr; relr < relrlim; relr++) { 3463 Elf_Relr entry = *relr; 3464 3465 if ((entry & 1) == 0) { 3466 where = (Elf_Addr *)(obj->relocbase + entry); 3467 *where++ += (Elf_Addr)obj->relocbase; 3468 } else { 3469 for (long i = 0; (entry >>= 1) != 0; i++) 3470 if ((entry & 1) != 0) 3471 where[i] += (Elf_Addr)obj->relocbase; 3472 where += CHAR_BIT * sizeof(Elf_Relr) - 1; 3473 } 3474 } 3475 } 3476 3477 /* 3478 * Relocate single object. 3479 * Returns 0 on success, or -1 on failure. 3480 */ 3481 static int 3482 relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, int flags, 3483 RtldLockState *lockstate) 3484 { 3485 if (obj->relocated) 3486 return (0); 3487 obj->relocated = true; 3488 if (obj != rtldobj) 3489 dbg("relocating \"%s\"", obj->path); 3490 3491 if (obj->symtab == NULL || obj->strtab == NULL || 3492 !(obj->valid_hash_sysv || obj->valid_hash_gnu)) 3493 dbg("object %s has no run-time symbol table", obj->path); 3494 3495 /* There are relocations to the write-protected text segment. */ 3496 if (obj->textrel && reloc_textrel_prot(obj, true) != 0) 3497 return (-1); 3498 3499 /* Process the non-PLT non-IFUNC relocations. */ 3500 if (reloc_non_plt(obj, rtldobj, flags, lockstate)) 3501 return (-1); 3502 reloc_relr(obj); 3503 3504 /* Re-protected the text segment. */ 3505 if (obj->textrel && reloc_textrel_prot(obj, false) != 0) 3506 return (-1); 3507 3508 /* Set the special PLT or GOT entries. */ 3509 init_pltgot(obj); 3510 3511 /* Process the PLT relocations. */ 3512 if (reloc_plt(obj, flags, lockstate) == -1) 3513 return (-1); 3514 /* Relocate the jump slots if we are doing immediate binding. */ 3515 if ((obj->bind_now || bind_now) && 3516 reloc_jmpslots(obj, flags, lockstate) == -1) 3517 return (-1); 3518 3519 if (obj != rtldobj && !obj->mainprog && obj_enforce_relro(obj) == -1) 3520 return (-1); 3521 3522 /* 3523 * Set up the magic number and version in the Obj_Entry. These 3524 * were checked in the crt1.o from the original ElfKit, so we 3525 * set them for backward compatibility. 3526 */ 3527 obj->magic = RTLD_MAGIC; 3528 obj->version = RTLD_VERSION; 3529 3530 return (0); 3531 } 3532 3533 /* 3534 * Relocate newly-loaded shared objects. The argument is a pointer to 3535 * the Obj_Entry for the first such object. All objects from the first 3536 * to the end of the list of objects are relocated. Returns 0 on success, 3537 * or -1 on failure. 3538 */ 3539 static int 3540 relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj, int flags, 3541 RtldLockState *lockstate) 3542 { 3543 Obj_Entry *obj; 3544 int error; 3545 3546 for (error = 0, obj = first; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 3547 if (obj->marker) 3548 continue; 3549 error = relocate_object(obj, bind_now, rtldobj, flags, 3550 lockstate); 3551 if (error == -1) 3552 break; 3553 } 3554 return (error); 3555 } 3556 3557 /* 3558 * The handling of R_MACHINE_IRELATIVE relocations and jumpslots 3559 * referencing STT_GNU_IFUNC symbols is postponed till the other 3560 * relocations are done. The indirect functions specified as 3561 * ifunc are allowed to call other symbols, so we need to have 3562 * objects relocated before asking for resolution from indirects. 3563 * 3564 * The R_MACHINE_IRELATIVE slots are resolved in greedy fashion, 3565 * instead of the usual lazy handling of PLT slots. It is 3566 * consistent with how GNU does it. 3567 */ 3568 static int 3569 resolve_object_ifunc(Obj_Entry *obj, bool bind_now, int flags, 3570 RtldLockState *lockstate) 3571 { 3572 if (obj->ifuncs_resolved) 3573 return (0); 3574 obj->ifuncs_resolved = true; 3575 if (!obj->irelative && !obj->irelative_nonplt && 3576 !((obj->bind_now || bind_now) && obj->gnu_ifunc) && 3577 !obj->non_plt_gnu_ifunc) 3578 return (0); 3579 if (obj_disable_relro(obj) == -1 || 3580 (obj->irelative && reloc_iresolve(obj, lockstate) == -1) || 3581 (obj->irelative_nonplt && 3582 reloc_iresolve_nonplt(obj, lockstate) == -1) || 3583 ((obj->bind_now || bind_now) && obj->gnu_ifunc && 3584 reloc_gnu_ifunc(obj, flags, lockstate) == -1) || 3585 (obj->non_plt_gnu_ifunc && 3586 reloc_non_plt(obj, &obj_rtld, flags | SYMLOOK_IFUNC, 3587 lockstate) == -1) || 3588 obj_enforce_relro(obj) == -1) 3589 return (-1); 3590 return (0); 3591 } 3592 3593 static int 3594 initlist_objects_ifunc(Objlist *list, bool bind_now, int flags, 3595 RtldLockState *lockstate) 3596 { 3597 Objlist_Entry *elm; 3598 Obj_Entry *obj; 3599 3600 STAILQ_FOREACH(elm, list, link) { 3601 obj = elm->obj; 3602 if (obj->marker) 3603 continue; 3604 if (resolve_object_ifunc(obj, bind_now, flags, lockstate) == -1) 3605 return (-1); 3606 } 3607 return (0); 3608 } 3609 3610 /* 3611 * Cleanup procedure. It will be called (by the atexit mechanism) just 3612 * before the process exits. 3613 */ 3614 static void 3615 rtld_exit(void) 3616 { 3617 RtldLockState lockstate; 3618 3619 wlock_acquire(rtld_bind_lock, &lockstate); 3620 dbg("rtld_exit()"); 3621 objlist_call_fini(&list_fini, NULL, &lockstate); 3622 /* No need to remove the items from the list, since we are exiting. */ 3623 if (!libmap_disable) 3624 lm_fini(); 3625 lock_release(rtld_bind_lock, &lockstate); 3626 } 3627 3628 static void 3629 rtld_nop_exit(void) 3630 { 3631 } 3632 3633 /* 3634 * Parse string of the format '#number/name", where number must be a 3635 * decimal number of the opened file descriptor listed in 3636 * LD_LIBRARY_PATH_FDS. If successful, tries to open dso name under 3637 * dirfd number and returns resulting fd. 3638 * On any error, returns -1. 3639 */ 3640 static int 3641 try_fds_open(const char *name, const char *path) 3642 { 3643 const char *n; 3644 char *envcopy, *fdstr, *last_token, *ncopy; 3645 size_t len; 3646 int fd, dirfd, dirfd_path; 3647 3648 if (!trust || name[0] != '#' || path == NULL) 3649 return (-1); 3650 3651 name++; 3652 n = strchr(name, '/'); 3653 if (n == NULL) 3654 return (-1); 3655 len = n - name; 3656 ncopy = xmalloc(len + 1); 3657 memcpy(ncopy, name, len); 3658 ncopy[len] = '\0'; 3659 dirfd = parse_integer(ncopy); 3660 free(ncopy); 3661 if (dirfd == -1) 3662 return (-1); 3663 3664 envcopy = xstrdup(path); 3665 dirfd_path = -1; 3666 for (fdstr = strtok_r(envcopy, ":", &last_token); fdstr != NULL; 3667 fdstr = strtok_r(NULL, ":", &last_token)) { 3668 dirfd_path = parse_integer(fdstr); 3669 if (dirfd_path == dirfd) 3670 break; 3671 } 3672 free(envcopy); 3673 if (dirfd_path != dirfd) 3674 return (-1); 3675 3676 fd = __sys_openat(dirfd, n + 1, O_RDONLY | O_CLOEXEC | O_VERIFY); 3677 return (fd); 3678 } 3679 3680 /* 3681 * Iterate over a search path, translate each element, and invoke the 3682 * callback on the result. 3683 */ 3684 static void * 3685 path_enumerate(const char *path, path_enum_proc callback, 3686 const char *refobj_path, void *arg) 3687 { 3688 const char *trans; 3689 if (path == NULL) 3690 return (NULL); 3691 3692 path += strspn(path, ":;"); 3693 while (*path != '\0') { 3694 size_t len; 3695 char *res; 3696 3697 len = strcspn(path, ":;"); 3698 trans = lm_findn(refobj_path, path, len); 3699 if (trans) 3700 res = callback(trans, strlen(trans), arg); 3701 else 3702 res = callback(path, len, arg); 3703 3704 if (res != NULL) 3705 return (res); 3706 3707 path += len; 3708 path += strspn(path, ":;"); 3709 } 3710 3711 return (NULL); 3712 } 3713 3714 struct try_library_args { 3715 const char *name; 3716 size_t namelen; 3717 char *buffer; 3718 size_t buflen; 3719 int fd; 3720 }; 3721 3722 static void * 3723 try_library_path(const char *dir, size_t dirlen, void *param) 3724 { 3725 struct try_library_args *arg; 3726 int fd; 3727 3728 arg = param; 3729 if (*dir == '/' || trust) { 3730 char *pathname; 3731 3732 if (dirlen + 1 + arg->namelen + 1 > arg->buflen) 3733 return (NULL); 3734 3735 pathname = arg->buffer; 3736 strncpy(pathname, dir, dirlen); 3737 pathname[dirlen] = '/'; 3738 strcpy(pathname + dirlen + 1, arg->name); 3739 3740 dbg(" Trying \"%s\"", pathname); 3741 fd = open(pathname, O_RDONLY | O_CLOEXEC | O_VERIFY); 3742 if (fd >= 0) { 3743 dbg(" Opened \"%s\", fd %d", pathname, fd); 3744 pathname = xmalloc(dirlen + 1 + arg->namelen + 1); 3745 strcpy(pathname, arg->buffer); 3746 arg->fd = fd; 3747 return (pathname); 3748 } else { 3749 dbg(" Failed to open \"%s\": %s", pathname, 3750 rtld_strerror(errno)); 3751 } 3752 } 3753 return (NULL); 3754 } 3755 3756 static char * 3757 search_library_path(const char *name, const char *path, const char *refobj_path, 3758 int *fdp) 3759 { 3760 char *p; 3761 struct try_library_args arg; 3762 3763 if (path == NULL) 3764 return (NULL); 3765 3766 arg.name = name; 3767 arg.namelen = strlen(name); 3768 arg.buffer = xmalloc(PATH_MAX); 3769 arg.buflen = PATH_MAX; 3770 arg.fd = -1; 3771 3772 p = path_enumerate(path, try_library_path, refobj_path, &arg); 3773 *fdp = arg.fd; 3774 3775 free(arg.buffer); 3776 3777 return (p); 3778 } 3779 3780 /* 3781 * Finds the library with the given name using the directory descriptors 3782 * listed in the LD_LIBRARY_PATH_FDS environment variable. 3783 * 3784 * Returns a freshly-opened close-on-exec file descriptor for the library, 3785 * or -1 if the library cannot be found. 3786 */ 3787 static char * 3788 search_library_pathfds(const char *name, const char *path, int *fdp) 3789 { 3790 char *envcopy, *fdstr, *found, *last_token; 3791 size_t len; 3792 int dirfd, fd; 3793 3794 dbg("%s('%s', '%s', fdp)", __func__, name, path); 3795 3796 /* Don't load from user-specified libdirs into setuid binaries. */ 3797 if (!trust) 3798 return (NULL); 3799 3800 /* We can't do anything if LD_LIBRARY_PATH_FDS isn't set. */ 3801 if (path == NULL) 3802 return (NULL); 3803 3804 /* LD_LIBRARY_PATH_FDS only works with relative paths. */ 3805 if (name[0] == '/') { 3806 dbg("Absolute path (%s) passed to %s", name, __func__); 3807 return (NULL); 3808 } 3809 3810 /* 3811 * Use strtok_r() to walk the FD:FD:FD list. This requires a local 3812 * copy of the path, as strtok_r rewrites separator tokens 3813 * with '\0'. 3814 */ 3815 found = NULL; 3816 envcopy = xstrdup(path); 3817 for (fdstr = strtok_r(envcopy, ":", &last_token); fdstr != NULL; 3818 fdstr = strtok_r(NULL, ":", &last_token)) { 3819 dirfd = parse_integer(fdstr); 3820 if (dirfd < 0) { 3821 _rtld_error("failed to parse directory FD: '%s'", 3822 fdstr); 3823 break; 3824 } 3825 fd = __sys_openat(dirfd, name, O_RDONLY | O_CLOEXEC | O_VERIFY); 3826 if (fd >= 0) { 3827 *fdp = fd; 3828 len = strlen(fdstr) + strlen(name) + 3; 3829 found = xmalloc(len); 3830 if (rtld_snprintf(found, len, "#%d/%s", dirfd, name) < 3831 0) { 3832 _rtld_error("error generating '%d/%s'", dirfd, 3833 name); 3834 rtld_die(); 3835 } 3836 dbg("open('%s') => %d", found, fd); 3837 break; 3838 } 3839 } 3840 free(envcopy); 3841 3842 return (found); 3843 } 3844 3845 int 3846 dlclose(void *handle) 3847 { 3848 RtldLockState lockstate; 3849 int error; 3850 3851 wlock_acquire(rtld_bind_lock, &lockstate); 3852 error = dlclose_locked(handle, &lockstate); 3853 lock_release(rtld_bind_lock, &lockstate); 3854 return (error); 3855 } 3856 3857 static int 3858 dlclose_locked(void *handle, RtldLockState *lockstate) 3859 { 3860 Obj_Entry *root; 3861 3862 root = dlcheck(handle); 3863 if (root == NULL) 3864 return (-1); 3865 LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount, 3866 root->path); 3867 3868 /* Unreference the object and its dependencies. */ 3869 root->dl_refcount--; 3870 3871 if (root->refcount == 1) { 3872 /* 3873 * The object will be no longer referenced, so we must unload 3874 * it. First, call the fini functions. 3875 */ 3876 objlist_call_fini(&list_fini, root, lockstate); 3877 3878 unref_dag(root); 3879 3880 /* Finish cleaning up the newly-unreferenced objects. */ 3881 GDB_STATE(RT_DELETE, &root->linkmap); 3882 unload_object(root, lockstate); 3883 GDB_STATE(RT_CONSISTENT, NULL); 3884 } else 3885 unref_dag(root); 3886 3887 LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL); 3888 return (0); 3889 } 3890 3891 char * 3892 dlerror(void) 3893 { 3894 if (*(lockinfo.dlerror_seen()) != 0) 3895 return (NULL); 3896 *lockinfo.dlerror_seen() = 1; 3897 return (lockinfo.dlerror_loc()); 3898 } 3899 3900 /* 3901 * This function is deprecated and has no effect. 3902 */ 3903 void 3904 dllockinit(void *context, void *(*_lock_create)(void *context)__unused, 3905 void (*_rlock_acquire)(void *lock) __unused, 3906 void (*_wlock_acquire)(void *lock) __unused, 3907 void (*_lock_release)(void *lock) __unused, 3908 void (*_lock_destroy)(void *lock) __unused, 3909 void (*context_destroy)(void *context)) 3910 { 3911 static void *cur_context; 3912 static void (*cur_context_destroy)(void *); 3913 3914 /* Just destroy the context from the previous call, if necessary. */ 3915 if (cur_context_destroy != NULL) 3916 cur_context_destroy(cur_context); 3917 cur_context = context; 3918 cur_context_destroy = context_destroy; 3919 } 3920 3921 void * 3922 dlopen(const char *name, int mode) 3923 { 3924 return (rtld_dlopen(name, -1, mode)); 3925 } 3926 3927 void * 3928 fdlopen(int fd, int mode) 3929 { 3930 return (rtld_dlopen(NULL, fd, mode)); 3931 } 3932 3933 static void * 3934 rtld_dlopen(const char *name, int fd, int mode) 3935 { 3936 RtldLockState lockstate; 3937 int lo_flags; 3938 3939 LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name); 3940 ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1"; 3941 if (ld_tracing != NULL) { 3942 rlock_acquire(rtld_bind_lock, &lockstate); 3943 if (sigsetjmp(lockstate.env, 0) != 0) 3944 lock_upgrade(rtld_bind_lock, &lockstate); 3945 environ = __DECONST(char **, 3946 *get_program_var_addr("environ", &lockstate)); 3947 lock_release(rtld_bind_lock, &lockstate); 3948 } 3949 lo_flags = RTLD_LO_DLOPEN; 3950 if (mode & RTLD_NODELETE) 3951 lo_flags |= RTLD_LO_NODELETE; 3952 if (mode & RTLD_NOLOAD) 3953 lo_flags |= RTLD_LO_NOLOAD; 3954 if (mode & RTLD_DEEPBIND) 3955 lo_flags |= RTLD_LO_DEEPBIND; 3956 if (ld_tracing != NULL) 3957 lo_flags |= RTLD_LO_TRACE | RTLD_LO_IGNSTLS; 3958 3959 return (dlopen_object(name, fd, obj_main, lo_flags, 3960 mode & (RTLD_MODEMASK | RTLD_GLOBAL), NULL)); 3961 } 3962 3963 static void 3964 dlopen_cleanup(Obj_Entry *obj, RtldLockState *lockstate) 3965 { 3966 obj->dl_refcount--; 3967 unref_dag(obj); 3968 if (obj->refcount == 0) 3969 unload_object(obj, lockstate); 3970 } 3971 3972 static Obj_Entry * 3973 dlopen_object(const char *name, int fd, Obj_Entry *refobj, int lo_flags, 3974 int mode, RtldLockState *lockstate) 3975 { 3976 Obj_Entry *obj; 3977 Objlist initlist; 3978 RtldLockState mlockstate; 3979 int result; 3980 3981 dbg( 3982 "dlopen_object name \"%s\" fd %d refobj \"%s\" lo_flags %#x mode %#x", 3983 name != NULL ? name : "<null>", fd, 3984 refobj == NULL ? "<null>" : refobj->path, lo_flags, mode); 3985 objlist_init(&initlist); 3986 3987 if (lockstate == NULL && !(lo_flags & RTLD_LO_EARLY)) { 3988 wlock_acquire(rtld_bind_lock, &mlockstate); 3989 lockstate = &mlockstate; 3990 } 3991 GDB_STATE(RT_ADD, NULL); 3992 3993 obj = NULL; 3994 if (name == NULL && fd == -1) { 3995 obj = obj_main; 3996 obj->refcount++; 3997 } else { 3998 obj = load_object(name, fd, refobj, lo_flags); 3999 } 4000 4001 if (obj != NULL) { 4002 obj->dl_refcount++; 4003 if ((mode & RTLD_GLOBAL) != 0 && 4004 objlist_find(&list_global, obj) == NULL) 4005 objlist_push_tail(&list_global, obj); 4006 4007 if (!obj->init_done) { 4008 /* We loaded something new and have to init something. 4009 */ 4010 if ((lo_flags & RTLD_LO_DEEPBIND) != 0) 4011 obj->deepbind = true; 4012 result = 0; 4013 if ((lo_flags & (RTLD_LO_EARLY | 4014 RTLD_LO_IGNSTLS)) == 0 && 4015 obj->static_tls && !allocate_tls_offset(obj)) { 4016 _rtld_error( 4017 "%s: No space available for static Thread Local Storage", 4018 obj->path); 4019 result = -1; 4020 } 4021 if (result != -1) 4022 result = load_needed_objects(obj, 4023 lo_flags & (RTLD_LO_DLOPEN | RTLD_LO_EARLY | 4024 RTLD_LO_IGNSTLS | RTLD_LO_TRACE)); 4025 init_dag(obj); 4026 ref_dag(obj); 4027 if (result != -1) 4028 result = rtld_verify_versions(&obj->dagmembers); 4029 if (result != -1 && ld_tracing) 4030 goto trace; 4031 if (result == -1 || relocate_object_dag(obj, 4032 (mode & RTLD_MODEMASK) == RTLD_NOW, &obj_rtld, 4033 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 4034 lockstate) == -1) { 4035 dlopen_cleanup(obj, lockstate); 4036 obj = NULL; 4037 } else if ((lo_flags & RTLD_LO_EARLY) != 0) { 4038 /* 4039 * Do not call the init functions for early 4040 * loaded filtees. The image is still not 4041 * initialized enough for them to work. 4042 * 4043 * Our object is found by the global object list 4044 * and will be ordered among all init calls done 4045 * right before transferring control to main. 4046 */ 4047 } else { 4048 /* Make list of init functions to call. */ 4049 initlist_for_loaded_obj(obj, obj, &initlist); 4050 } 4051 /* 4052 * Process all no_delete or global objects here, given 4053 * them own DAGs to prevent their dependencies from 4054 * being unloaded. This has to be done after we have 4055 * loaded all of the dependencies, so that we do not 4056 * miss any. 4057 */ 4058 if (obj != NULL) 4059 process_z(obj); 4060 } else { 4061 /* 4062 * Bump the reference counts for objects on this DAG. If 4063 * this is the first dlopen() call for the object that 4064 * was already loaded as a dependency, initialize the 4065 * dag starting at it. 4066 */ 4067 init_dag(obj); 4068 ref_dag(obj); 4069 4070 if ((lo_flags & RTLD_LO_TRACE) != 0) 4071 goto trace; 4072 } 4073 if (obj != NULL && 4074 ((lo_flags & RTLD_LO_NODELETE) != 0 || obj->z_nodelete) && 4075 !obj->ref_nodel) { 4076 dbg("obj %s nodelete", obj->path); 4077 ref_dag(obj); 4078 obj->z_nodelete = obj->ref_nodel = true; 4079 } 4080 } 4081 4082 LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0, 4083 name); 4084 GDB_STATE(RT_CONSISTENT, obj ? &obj->linkmap : NULL); 4085 4086 if ((lo_flags & RTLD_LO_EARLY) == 0) { 4087 map_stacks_exec(lockstate); 4088 if (obj != NULL) 4089 distribute_static_tls(&initlist); 4090 } 4091 4092 if (initlist_objects_ifunc(&initlist, (mode & RTLD_MODEMASK) == 4093 RTLD_NOW, (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 4094 lockstate) == -1) { 4095 objlist_clear(&initlist); 4096 dlopen_cleanup(obj, lockstate); 4097 if (lockstate == &mlockstate) 4098 lock_release(rtld_bind_lock, lockstate); 4099 return (NULL); 4100 } 4101 4102 if ((lo_flags & RTLD_LO_EARLY) == 0) { 4103 /* Call the init functions. */ 4104 objlist_call_init(&initlist, lockstate); 4105 } 4106 objlist_clear(&initlist); 4107 if (lockstate == &mlockstate) 4108 lock_release(rtld_bind_lock, lockstate); 4109 return (obj); 4110 trace: 4111 trace_loaded_objects(obj, false); 4112 if (lockstate == &mlockstate) 4113 lock_release(rtld_bind_lock, lockstate); 4114 exit(0); 4115 } 4116 4117 static void * 4118 do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve, 4119 int flags) 4120 { 4121 DoneList donelist; 4122 const Obj_Entry *obj, *defobj; 4123 const Elf_Sym *def; 4124 SymLook req; 4125 RtldLockState lockstate; 4126 tls_index ti; 4127 void *sym; 4128 int res; 4129 4130 def = NULL; 4131 defobj = NULL; 4132 symlook_init(&req, name); 4133 req.ventry = ve; 4134 req.flags = flags | SYMLOOK_IN_PLT; 4135 req.lockstate = &lockstate; 4136 4137 LD_UTRACE(UTRACE_DLSYM_START, handle, NULL, 0, 0, name); 4138 rlock_acquire(rtld_bind_lock, &lockstate); 4139 if (sigsetjmp(lockstate.env, 0) != 0) { 4140 lock_upgrade(rtld_bind_lock, &lockstate); 4141 free(req.donelist_mem); 4142 req.donelist_mem = NULL; 4143 } 4144 if (handle == NULL || handle == RTLD_NEXT || handle == RTLD_DEFAULT || 4145 handle == RTLD_SELF) { 4146 if ((obj = obj_from_addr(retaddr)) == NULL) { 4147 _rtld_error("Cannot determine caller's shared object"); 4148 lock_release(rtld_bind_lock, &lockstate); 4149 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 4150 return (NULL); 4151 } 4152 if (handle == NULL) { /* Just the caller's shared object. */ 4153 res = symlook_obj(&req, obj); 4154 if (res == 0) { 4155 def = req.sym_out; 4156 defobj = req.defobj_out; 4157 } 4158 } else if (handle == RTLD_NEXT || /* Objects after caller's */ 4159 handle == RTLD_SELF) { /* ... caller included */ 4160 if (handle == RTLD_NEXT) 4161 obj = globallist_next(obj); 4162 for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 4163 if (obj->marker) 4164 continue; 4165 res = symlook_obj(&req, obj); 4166 if (res == 0) { 4167 if (def == NULL || 4168 (ld_dynamic_weak && 4169 ELF_ST_BIND( 4170 req.sym_out->st_info) != 4171 STB_WEAK)) { 4172 def = req.sym_out; 4173 defobj = req.defobj_out; 4174 if (!ld_dynamic_weak || 4175 ELF_ST_BIND(def->st_info) != 4176 STB_WEAK) 4177 break; 4178 } 4179 } 4180 } 4181 /* 4182 * Search the dynamic linker itself, and possibly 4183 * resolve the symbol from there. This is how the 4184 * application links to dynamic linker services such as 4185 * dlopen. Note that we ignore ld_dynamic_weak == false 4186 * case, always overriding weak symbols by rtld 4187 * definitions. 4188 */ 4189 if (def == NULL || 4190 ELF_ST_BIND(def->st_info) == STB_WEAK) { 4191 res = symlook_obj(&req, &obj_rtld); 4192 if (res == 0) { 4193 def = req.sym_out; 4194 defobj = req.defobj_out; 4195 } 4196 } 4197 } else { 4198 assert(handle == RTLD_DEFAULT); 4199 res = symlook_default(&req, obj); 4200 if (res == 0) { 4201 defobj = req.defobj_out; 4202 def = req.sym_out; 4203 } 4204 } 4205 } else { 4206 if ((obj = dlcheck(handle)) == NULL) { 4207 lock_release(rtld_bind_lock, &lockstate); 4208 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 4209 return (NULL); 4210 } 4211 4212 donelist_init(&donelist, &req); 4213 if (obj->mainprog) { 4214 /* Handle obtained by dlopen(NULL, ...) implies global 4215 * scope. */ 4216 res = symlook_global(&req, &donelist); 4217 if (res == 0) { 4218 def = req.sym_out; 4219 defobj = req.defobj_out; 4220 } 4221 /* 4222 * Search the dynamic linker itself, and possibly 4223 * resolve the symbol from there. This is how the 4224 * application links to dynamic linker services such as 4225 * dlopen. 4226 */ 4227 if (def == NULL || 4228 ELF_ST_BIND(def->st_info) == STB_WEAK) { 4229 res = symlook_obj(&req, &obj_rtld); 4230 if (res == 0) { 4231 def = req.sym_out; 4232 defobj = req.defobj_out; 4233 } 4234 } 4235 } else { 4236 /* Search the whole DAG rooted at the given object. */ 4237 res = symlook_list(&req, &obj->dagmembers, &donelist); 4238 if (res == 0) { 4239 def = req.sym_out; 4240 defobj = req.defobj_out; 4241 } 4242 } 4243 donelist_free(&donelist); 4244 } 4245 4246 if (def != NULL) { 4247 lock_release(rtld_bind_lock, &lockstate); 4248 4249 /* 4250 * The value required by the caller is derived from the value 4251 * of the symbol. this is simply the relocated value of the 4252 * symbol. 4253 */ 4254 if (ELF_ST_TYPE(def->st_info) == STT_FUNC) 4255 sym = make_function_pointer(def, defobj); 4256 else if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 4257 sym = rtld_resolve_ifunc(defobj, def); 4258 else if (ELF_ST_TYPE(def->st_info) == STT_TLS) { 4259 ti.ti_module = defobj->tlsindex; 4260 ti.ti_offset = def->st_value - TLS_DTV_OFFSET; 4261 sym = __tls_get_addr(&ti); 4262 } else 4263 sym = defobj->relocbase + def->st_value; 4264 LD_UTRACE(UTRACE_DLSYM_STOP, handle, sym, 0, 0, name); 4265 return (sym); 4266 } 4267 4268 _rtld_error("Undefined symbol \"%s%s%s\"", name, ve != NULL ? "@" : "", 4269 ve != NULL ? ve->name : ""); 4270 lock_release(rtld_bind_lock, &lockstate); 4271 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name); 4272 return (NULL); 4273 } 4274 4275 void * 4276 dlsym(void *handle, const char *name) 4277 { 4278 return (do_dlsym(handle, name, __builtin_return_address(0), NULL, 4279 SYMLOOK_DLSYM)); 4280 } 4281 4282 dlfunc_t 4283 dlfunc(void *handle, const char *name) 4284 { 4285 union { 4286 void *d; 4287 dlfunc_t f; 4288 } rv; 4289 4290 rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL, 4291 SYMLOOK_DLSYM); 4292 return (rv.f); 4293 } 4294 4295 void * 4296 dlvsym(void *handle, const char *name, const char *version) 4297 { 4298 Ver_Entry ventry; 4299 4300 ventry.name = version; 4301 ventry.file = NULL; 4302 ventry.hash = elf_hash(version); 4303 ventry.flags = 0; 4304 return (do_dlsym(handle, name, __builtin_return_address(0), &ventry, 4305 SYMLOOK_DLSYM)); 4306 } 4307 4308 int 4309 _rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info) 4310 { 4311 const Obj_Entry *obj; 4312 RtldLockState lockstate; 4313 4314 rlock_acquire(rtld_bind_lock, &lockstate); 4315 obj = obj_from_addr(addr); 4316 if (obj == NULL) { 4317 _rtld_error("No shared object contains address"); 4318 lock_release(rtld_bind_lock, &lockstate); 4319 return (0); 4320 } 4321 rtld_fill_dl_phdr_info(obj, phdr_info); 4322 lock_release(rtld_bind_lock, &lockstate); 4323 return (1); 4324 } 4325 4326 int 4327 dladdr(const void *addr, Dl_info *info) 4328 { 4329 const Obj_Entry *obj; 4330 const Elf_Sym *def; 4331 void *symbol_addr; 4332 unsigned long symoffset; 4333 RtldLockState lockstate; 4334 4335 rlock_acquire(rtld_bind_lock, &lockstate); 4336 obj = obj_from_addr(addr); 4337 if (obj == NULL) { 4338 _rtld_error("No shared object contains address"); 4339 lock_release(rtld_bind_lock, &lockstate); 4340 return (0); 4341 } 4342 info->dli_fname = obj->path; 4343 info->dli_fbase = obj->mapbase; 4344 info->dli_saddr = (void *)0; 4345 info->dli_sname = NULL; 4346 4347 /* 4348 * Walk the symbol list looking for the symbol whose address is 4349 * closest to the address sent in. 4350 */ 4351 for (symoffset = 0; symoffset < obj->dynsymcount; symoffset++) { 4352 def = obj->symtab + symoffset; 4353 4354 /* 4355 * For skip the symbol if st_shndx is either SHN_UNDEF or 4356 * SHN_COMMON. 4357 */ 4358 if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON) 4359 continue; 4360 4361 /* 4362 * If the symbol is greater than the specified address, or if it 4363 * is further away from addr than the current nearest symbol, 4364 * then reject it. 4365 */ 4366 symbol_addr = obj->relocbase + def->st_value; 4367 if (symbol_addr > addr || symbol_addr < info->dli_saddr) 4368 continue; 4369 4370 /* Update our idea of the nearest symbol. */ 4371 info->dli_sname = obj->strtab + def->st_name; 4372 info->dli_saddr = symbol_addr; 4373 4374 /* Exact match? */ 4375 if (info->dli_saddr == addr) 4376 break; 4377 } 4378 lock_release(rtld_bind_lock, &lockstate); 4379 return (1); 4380 } 4381 4382 int 4383 dlinfo(void *handle, int request, void *p) 4384 { 4385 const Obj_Entry *obj; 4386 RtldLockState lockstate; 4387 int error; 4388 4389 rlock_acquire(rtld_bind_lock, &lockstate); 4390 4391 if (handle == NULL || handle == RTLD_SELF) { 4392 void *retaddr; 4393 4394 retaddr = __builtin_return_address(0); /* __GNUC__ only */ 4395 if ((obj = obj_from_addr(retaddr)) == NULL) 4396 _rtld_error("Cannot determine caller's shared object"); 4397 } else 4398 obj = dlcheck(handle); 4399 4400 if (obj == NULL) { 4401 lock_release(rtld_bind_lock, &lockstate); 4402 return (-1); 4403 } 4404 4405 error = 0; 4406 switch (request) { 4407 case RTLD_DI_LINKMAP: 4408 *((struct link_map const **)p) = &obj->linkmap; 4409 break; 4410 case RTLD_DI_ORIGIN: 4411 error = rtld_dirname(obj->path, p); 4412 break; 4413 4414 case RTLD_DI_SERINFOSIZE: 4415 case RTLD_DI_SERINFO: 4416 error = do_search_info(obj, request, (struct dl_serinfo *)p); 4417 break; 4418 4419 default: 4420 _rtld_error("Invalid request %d passed to dlinfo()", request); 4421 error = -1; 4422 } 4423 4424 lock_release(rtld_bind_lock, &lockstate); 4425 4426 return (error); 4427 } 4428 4429 static void 4430 rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info) 4431 { 4432 phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase; 4433 phdr_info->dlpi_name = obj->path; 4434 phdr_info->dlpi_phdr = obj->phdr; 4435 phdr_info->dlpi_phnum = obj->phnum; 4436 phdr_info->dlpi_tls_modid = obj->tlsindex; 4437 phdr_info->dlpi_tls_data = (char *)tls_get_addr_slow(_tcb_get(), 4438 obj->tlsindex, 0, true); 4439 phdr_info->dlpi_adds = obj_loads; 4440 phdr_info->dlpi_subs = obj_loads - obj_count; 4441 } 4442 4443 /* 4444 * It's completely UB to actually use this, so extreme caution is advised. It's 4445 * probably not what you want. 4446 */ 4447 int 4448 _dl_iterate_phdr_locked(__dl_iterate_hdr_callback callback, void *param) 4449 { 4450 struct dl_phdr_info phdr_info; 4451 Obj_Entry *obj; 4452 int error; 4453 4454 for (obj = globallist_curr(TAILQ_FIRST(&obj_list)); obj != NULL; 4455 obj = globallist_next(obj)) { 4456 rtld_fill_dl_phdr_info(obj, &phdr_info); 4457 error = callback(&phdr_info, sizeof(phdr_info), param); 4458 if (error != 0) 4459 return (error); 4460 } 4461 4462 rtld_fill_dl_phdr_info(&obj_rtld, &phdr_info); 4463 return (callback(&phdr_info, sizeof(phdr_info), param)); 4464 } 4465 4466 int 4467 dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param) 4468 { 4469 struct dl_phdr_info phdr_info; 4470 Obj_Entry *obj, marker; 4471 RtldLockState bind_lockstate, phdr_lockstate; 4472 int error; 4473 4474 init_marker(&marker); 4475 error = 0; 4476 4477 wlock_acquire(rtld_phdr_lock, &phdr_lockstate); 4478 wlock_acquire(rtld_bind_lock, &bind_lockstate); 4479 for (obj = globallist_curr(TAILQ_FIRST(&obj_list)); obj != NULL;) { 4480 TAILQ_INSERT_AFTER(&obj_list, obj, &marker, next); 4481 rtld_fill_dl_phdr_info(obj, &phdr_info); 4482 hold_object(obj); 4483 lock_release(rtld_bind_lock, &bind_lockstate); 4484 4485 error = callback(&phdr_info, sizeof phdr_info, param); 4486 4487 wlock_acquire(rtld_bind_lock, &bind_lockstate); 4488 unhold_object(obj); 4489 obj = globallist_next(&marker); 4490 TAILQ_REMOVE(&obj_list, &marker, next); 4491 if (error != 0) { 4492 lock_release(rtld_bind_lock, &bind_lockstate); 4493 lock_release(rtld_phdr_lock, &phdr_lockstate); 4494 return (error); 4495 } 4496 } 4497 4498 if (error == 0) { 4499 rtld_fill_dl_phdr_info(&obj_rtld, &phdr_info); 4500 lock_release(rtld_bind_lock, &bind_lockstate); 4501 error = callback(&phdr_info, sizeof(phdr_info), param); 4502 } 4503 lock_release(rtld_phdr_lock, &phdr_lockstate); 4504 return (error); 4505 } 4506 4507 static void * 4508 fill_search_info(const char *dir, size_t dirlen, void *param) 4509 { 4510 struct fill_search_info_args *arg; 4511 4512 arg = param; 4513 4514 if (arg->request == RTLD_DI_SERINFOSIZE) { 4515 arg->serinfo->dls_cnt++; 4516 arg->serinfo->dls_size += sizeof(struct dl_serpath) + dirlen + 4517 1; 4518 } else { 4519 struct dl_serpath *s_entry; 4520 4521 s_entry = arg->serpath; 4522 s_entry->dls_name = arg->strspace; 4523 s_entry->dls_flags = arg->flags; 4524 4525 strncpy(arg->strspace, dir, dirlen); 4526 arg->strspace[dirlen] = '\0'; 4527 4528 arg->strspace += dirlen + 1; 4529 arg->serpath++; 4530 } 4531 4532 return (NULL); 4533 } 4534 4535 static int 4536 do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info) 4537 { 4538 struct dl_serinfo _info; 4539 struct fill_search_info_args args; 4540 4541 args.request = RTLD_DI_SERINFOSIZE; 4542 args.serinfo = &_info; 4543 4544 _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 4545 _info.dls_cnt = 0; 4546 4547 path_enumerate(obj->rpath, fill_search_info, NULL, &args); 4548 path_enumerate(ld_library_path, fill_search_info, NULL, &args); 4549 path_enumerate(obj->runpath, fill_search_info, NULL, &args); 4550 path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, 4551 &args); 4552 if (!obj->z_nodeflib) 4553 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 4554 &args); 4555 4556 if (request == RTLD_DI_SERINFOSIZE) { 4557 info->dls_size = _info.dls_size; 4558 info->dls_cnt = _info.dls_cnt; 4559 return (0); 4560 } 4561 4562 if (info->dls_cnt != _info.dls_cnt || 4563 info->dls_size != _info.dls_size) { 4564 _rtld_error( 4565 "Uninitialized Dl_serinfo struct passed to dlinfo()"); 4566 return (-1); 4567 } 4568 4569 args.request = RTLD_DI_SERINFO; 4570 args.serinfo = info; 4571 args.serpath = &info->dls_serpath[0]; 4572 args.strspace = (char *)&info->dls_serpath[_info.dls_cnt]; 4573 4574 args.flags = LA_SER_RUNPATH; 4575 if (path_enumerate(obj->rpath, fill_search_info, NULL, &args) != NULL) 4576 return (-1); 4577 4578 args.flags = LA_SER_LIBPATH; 4579 if (path_enumerate(ld_library_path, fill_search_info, NULL, &args) != 4580 NULL) 4581 return (-1); 4582 4583 args.flags = LA_SER_RUNPATH; 4584 if (path_enumerate(obj->runpath, fill_search_info, NULL, &args) != NULL) 4585 return (-1); 4586 4587 args.flags = LA_SER_CONFIG; 4588 if (path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, 4589 &args) != NULL) 4590 return (-1); 4591 4592 args.flags = LA_SER_DEFAULT; 4593 if (!obj->z_nodeflib && 4594 path_enumerate(ld_standard_library_path, fill_search_info, NULL, 4595 &args) != NULL) 4596 return (-1); 4597 return (0); 4598 } 4599 4600 static int 4601 rtld_dirname(const char *path, char *bname) 4602 { 4603 const char *endp; 4604 4605 /* Empty or NULL string gets treated as "." */ 4606 if (path == NULL || *path == '\0') { 4607 bname[0] = '.'; 4608 bname[1] = '\0'; 4609 return (0); 4610 } 4611 4612 /* Strip trailing slashes */ 4613 endp = path + strlen(path) - 1; 4614 while (endp > path && *endp == '/') 4615 endp--; 4616 4617 /* Find the start of the dir */ 4618 while (endp > path && *endp != '/') 4619 endp--; 4620 4621 /* Either the dir is "/" or there are no slashes */ 4622 if (endp == path) { 4623 bname[0] = *endp == '/' ? '/' : '.'; 4624 bname[1] = '\0'; 4625 return (0); 4626 } else { 4627 do { 4628 endp--; 4629 } while (endp > path && *endp == '/'); 4630 } 4631 4632 if (endp - path + 2 > PATH_MAX) { 4633 _rtld_error("Filename is too long: %s", path); 4634 return (-1); 4635 } 4636 4637 strncpy(bname, path, endp - path + 1); 4638 bname[endp - path + 1] = '\0'; 4639 return (0); 4640 } 4641 4642 static int 4643 rtld_dirname_abs(const char *path, char *base) 4644 { 4645 char *last; 4646 4647 if (realpath(path, base) == NULL) { 4648 _rtld_error("realpath \"%s\" failed (%s)", path, 4649 rtld_strerror(errno)); 4650 return (-1); 4651 } 4652 dbg("%s -> %s", path, base); 4653 last = strrchr(base, '/'); 4654 if (last == NULL) { 4655 _rtld_error("non-abs result from realpath \"%s\"", path); 4656 return (-1); 4657 } 4658 if (last != base) 4659 *last = '\0'; 4660 return (0); 4661 } 4662 4663 static void 4664 linkmap_add(Obj_Entry *obj) 4665 { 4666 struct link_map *l, *prev; 4667 4668 l = &obj->linkmap; 4669 l->l_name = obj->path; 4670 l->l_base = obj->mapbase; 4671 l->l_ld = obj->dynamic; 4672 l->l_addr = obj->relocbase; 4673 4674 if (r_debug.r_map == NULL) { 4675 r_debug.r_map = l; 4676 return; 4677 } 4678 4679 /* 4680 * Scan to the end of the list, but not past the entry for the 4681 * dynamic linker, which we want to keep at the very end. 4682 */ 4683 for (prev = r_debug.r_map; 4684 prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap; 4685 prev = prev->l_next) 4686 ; 4687 4688 /* Link in the new entry. */ 4689 l->l_prev = prev; 4690 l->l_next = prev->l_next; 4691 if (l->l_next != NULL) 4692 l->l_next->l_prev = l; 4693 prev->l_next = l; 4694 } 4695 4696 static void 4697 linkmap_delete(Obj_Entry *obj) 4698 { 4699 struct link_map *l; 4700 4701 l = &obj->linkmap; 4702 if (l->l_prev == NULL) { 4703 if ((r_debug.r_map = l->l_next) != NULL) 4704 l->l_next->l_prev = NULL; 4705 return; 4706 } 4707 4708 if ((l->l_prev->l_next = l->l_next) != NULL) 4709 l->l_next->l_prev = l->l_prev; 4710 } 4711 4712 /* 4713 * Function for the debugger to set a breakpoint on to gain control. 4714 * 4715 * The two parameters allow the debugger to easily find and determine 4716 * what the runtime loader is doing and to whom it is doing it. 4717 * 4718 * When the loadhook trap is hit (r_debug_state, set at program 4719 * initialization), the arguments can be found on the stack: 4720 * 4721 * +8 struct link_map *m 4722 * +4 struct r_debug *rd 4723 * +0 RetAddr 4724 */ 4725 void 4726 r_debug_state(struct r_debug *rd __unused, struct link_map *m __unused) 4727 { 4728 /* 4729 * The following is a hack to force the compiler to emit calls to 4730 * this function, even when optimizing. If the function is empty, 4731 * the compiler is not obliged to emit any code for calls to it, 4732 * even when marked __noinline. However, gdb depends on those 4733 * calls being made. 4734 */ 4735 __compiler_membar(); 4736 } 4737 4738 /* 4739 * A function called after init routines have completed. This can be used to 4740 * break before a program's entry routine is called, and can be used when 4741 * main is not available in the symbol table. 4742 */ 4743 void 4744 _r_debug_postinit(struct link_map *m __unused) 4745 { 4746 /* See r_debug_state(). */ 4747 __compiler_membar(); 4748 } 4749 4750 static void 4751 release_object(Obj_Entry *obj) 4752 { 4753 if (obj->holdcount > 0) { 4754 obj->unholdfree = true; 4755 return; 4756 } 4757 munmap(obj->mapbase, obj->mapsize); 4758 linkmap_delete(obj); 4759 obj_free(obj); 4760 } 4761 4762 /* 4763 * Get address of the pointer variable in the main program. 4764 * Prefer non-weak symbol over the weak one. 4765 */ 4766 static const void ** 4767 get_program_var_addr(const char *name, RtldLockState *lockstate) 4768 { 4769 SymLook req; 4770 DoneList donelist; 4771 const void **res; 4772 4773 symlook_init(&req, name); 4774 req.lockstate = lockstate; 4775 donelist_init(&donelist, NULL); 4776 if (symlook_global(&req, &donelist) != 0) 4777 return (NULL); 4778 if (ELF_ST_TYPE(req.sym_out->st_info) == STT_FUNC) 4779 res = (const void **)make_function_pointer(req.sym_out, 4780 req.defobj_out); 4781 else if (ELF_ST_TYPE(req.sym_out->st_info) == STT_GNU_IFUNC) 4782 res = (const void **)rtld_resolve_ifunc(req.defobj_out, 4783 req.sym_out); 4784 else 4785 res = (const void **)(req.defobj_out->relocbase + 4786 req.sym_out->st_value); 4787 donelist_free(&donelist); 4788 return (res); 4789 } 4790 4791 /* 4792 * Set a pointer variable in the main program to the given value. This 4793 * is used to set key variables such as "environ" before any of the 4794 * init functions are called. 4795 */ 4796 static void 4797 set_program_var(const char *name, const void *value) 4798 { 4799 const void **addr; 4800 4801 if ((addr = get_program_var_addr(name, NULL)) != NULL) { 4802 dbg("\"%s\": *%p <-- %p", name, addr, value); 4803 *addr = value; 4804 } 4805 } 4806 4807 /* 4808 * Search the global objects, including dependencies and main object, 4809 * for the given symbol. 4810 */ 4811 static int 4812 symlook_global(SymLook *req, DoneList *donelist) 4813 { 4814 SymLook req1; 4815 const Objlist_Entry *elm; 4816 int res; 4817 4818 symlook_init_from_req(&req1, req); 4819 4820 /* Search all objects loaded at program start up. */ 4821 if (req->defobj_out == NULL || (ld_dynamic_weak && 4822 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK)) { 4823 res = symlook_list(&req1, &list_main, donelist); 4824 if (res == 0 && (!ld_dynamic_weak || req->defobj_out == NULL || 4825 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4826 req->sym_out = req1.sym_out; 4827 req->defobj_out = req1.defobj_out; 4828 assert(req->defobj_out != NULL); 4829 } 4830 } 4831 4832 /* Search all DAGs whose roots are RTLD_GLOBAL objects. */ 4833 STAILQ_FOREACH(elm, &list_global, link) { 4834 if (req->defobj_out != NULL && (!ld_dynamic_weak || 4835 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK)) 4836 break; 4837 res = symlook_list(&req1, &elm->obj->dagmembers, donelist); 4838 if (res == 0 && (req->defobj_out == NULL || 4839 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4840 req->sym_out = req1.sym_out; 4841 req->defobj_out = req1.defobj_out; 4842 assert(req->defobj_out != NULL); 4843 } 4844 } 4845 4846 return (req->sym_out != NULL ? 0 : ESRCH); 4847 } 4848 4849 /* 4850 * Given a symbol name in a referencing object, find the corresponding 4851 * definition of the symbol. Returns a pointer to the symbol, or NULL if 4852 * no definition was found. Returns a pointer to the Obj_Entry of the 4853 * defining object via the reference parameter DEFOBJ_OUT. 4854 */ 4855 static int 4856 symlook_default(SymLook *req, const Obj_Entry *refobj) 4857 { 4858 DoneList donelist; 4859 const Objlist_Entry *elm; 4860 SymLook req1; 4861 int res; 4862 4863 donelist_init(&donelist, req); 4864 symlook_init_from_req(&req1, req); 4865 4866 /* 4867 * Look first in the referencing object if linked symbolically, 4868 * and similarly handle protected symbols. 4869 */ 4870 res = symlook_obj(&req1, refobj); 4871 if (res == 0 && (refobj->symbolic || 4872 ELF_ST_VISIBILITY(req1.sym_out->st_other) == STV_PROTECTED || 4873 refobj->deepbind)) { 4874 req->sym_out = req1.sym_out; 4875 req->defobj_out = req1.defobj_out; 4876 assert(req->defobj_out != NULL); 4877 } 4878 if (refobj->symbolic || req->defobj_out != NULL || refobj->deepbind) 4879 donelist_check(&donelist, refobj); 4880 4881 if (!refobj->deepbind) 4882 symlook_global(req, &donelist); 4883 4884 /* Search all dlopened DAGs containing the referencing object. */ 4885 STAILQ_FOREACH(elm, &refobj->dldags, link) { 4886 if (req->sym_out != NULL && (!ld_dynamic_weak || 4887 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK)) 4888 break; 4889 res = symlook_list(&req1, &elm->obj->dagmembers, &donelist); 4890 if (res == 0 && (req->sym_out == NULL || 4891 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4892 req->sym_out = req1.sym_out; 4893 req->defobj_out = req1.defobj_out; 4894 assert(req->defobj_out != NULL); 4895 } 4896 } 4897 4898 if (refobj->deepbind) 4899 symlook_global(req, &donelist); 4900 4901 /* 4902 * Search the dynamic linker itself, and possibly resolve the 4903 * symbol from there. This is how the application links to 4904 * dynamic linker services such as dlopen. 4905 */ 4906 if (req->sym_out == NULL || 4907 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 4908 res = symlook_obj(&req1, &obj_rtld); 4909 if (res == 0) { 4910 req->sym_out = req1.sym_out; 4911 req->defobj_out = req1.defobj_out; 4912 assert(req->defobj_out != NULL); 4913 } 4914 } 4915 4916 donelist_free(&donelist); 4917 return (req->sym_out != NULL ? 0 : ESRCH); 4918 } 4919 4920 static int 4921 symlook_list(SymLook *req, const Objlist *objlist, DoneList *dlp) 4922 { 4923 const Elf_Sym *def; 4924 const Obj_Entry *defobj; 4925 const Objlist_Entry *elm; 4926 SymLook req1; 4927 int res; 4928 4929 def = NULL; 4930 defobj = NULL; 4931 STAILQ_FOREACH(elm, objlist, link) { 4932 if (donelist_check(dlp, elm->obj)) 4933 continue; 4934 symlook_init_from_req(&req1, req); 4935 if ((res = symlook_obj(&req1, elm->obj)) == 0) { 4936 if (def == NULL || (ld_dynamic_weak && 4937 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4938 def = req1.sym_out; 4939 defobj = req1.defobj_out; 4940 if (!ld_dynamic_weak || 4941 ELF_ST_BIND(def->st_info) != STB_WEAK) 4942 break; 4943 } 4944 } 4945 } 4946 if (def != NULL) { 4947 req->sym_out = def; 4948 req->defobj_out = defobj; 4949 return (0); 4950 } 4951 return (ESRCH); 4952 } 4953 4954 /* 4955 * Search the chain of DAGS cointed to by the given Needed_Entry 4956 * for a symbol of the given name. Each DAG is scanned completely 4957 * before advancing to the next one. Returns a pointer to the symbol, 4958 * or NULL if no definition was found. 4959 */ 4960 static int 4961 symlook_needed(SymLook *req, const Needed_Entry *needed, DoneList *dlp) 4962 { 4963 const Elf_Sym *def; 4964 const Needed_Entry *n; 4965 const Obj_Entry *defobj; 4966 SymLook req1; 4967 int res; 4968 4969 def = NULL; 4970 defobj = NULL; 4971 symlook_init_from_req(&req1, req); 4972 for (n = needed; n != NULL; n = n->next) { 4973 if (n->obj == NULL || (res = symlook_list(&req1, 4974 &n->obj->dagmembers, dlp)) != 0) 4975 continue; 4976 if (def == NULL || (ld_dynamic_weak && 4977 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 4978 def = req1.sym_out; 4979 defobj = req1.defobj_out; 4980 if (!ld_dynamic_weak || 4981 ELF_ST_BIND(def->st_info) != STB_WEAK) 4982 break; 4983 } 4984 } 4985 if (def != NULL) { 4986 req->sym_out = def; 4987 req->defobj_out = defobj; 4988 return (0); 4989 } 4990 return (ESRCH); 4991 } 4992 4993 static int 4994 symlook_obj_load_filtees(SymLook *req, SymLook *req1, const Obj_Entry *obj, 4995 Needed_Entry *needed) 4996 { 4997 DoneList donelist; 4998 int flags, res; 4999 5000 flags = (req->flags & SYMLOOK_EARLY) != 0 ? RTLD_LO_EARLY : 0; 5001 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 5002 donelist_init(&donelist, NULL); 5003 symlook_init_from_req(req1, req); 5004 res = symlook_needed(req1, needed, &donelist); 5005 donelist_free(&donelist); 5006 return (res); 5007 } 5008 5009 /* 5010 * Search the symbol table of a single shared object for a symbol of 5011 * the given name and version, if requested. Returns a pointer to the 5012 * symbol, or NULL if no definition was found. If the object is 5013 * filter, return filtered symbol from filtee. 5014 * 5015 * The symbol's hash value is passed in for efficiency reasons; that 5016 * eliminates many recomputations of the hash value. 5017 */ 5018 int 5019 symlook_obj(SymLook *req, const Obj_Entry *obj) 5020 { 5021 SymLook req1; 5022 int res, mres; 5023 5024 /* 5025 * If there is at least one valid hash at this point, we prefer to 5026 * use the faster GNU version if available. 5027 */ 5028 if (obj->valid_hash_gnu) 5029 mres = symlook_obj1_gnu(req, obj); 5030 else if (obj->valid_hash_sysv) 5031 mres = symlook_obj1_sysv(req, obj); 5032 else 5033 return (EINVAL); 5034 5035 if (mres == 0) { 5036 if (obj->needed_filtees != NULL) { 5037 res = symlook_obj_load_filtees(req, &req1, obj, 5038 obj->needed_filtees); 5039 if (res == 0) { 5040 req->sym_out = req1.sym_out; 5041 req->defobj_out = req1.defobj_out; 5042 } 5043 return (res); 5044 } 5045 if (obj->needed_aux_filtees != NULL) { 5046 res = symlook_obj_load_filtees(req, &req1, obj, 5047 obj->needed_aux_filtees); 5048 if (res == 0) { 5049 req->sym_out = req1.sym_out; 5050 req->defobj_out = req1.defobj_out; 5051 return (res); 5052 } 5053 } 5054 } 5055 return (mres); 5056 } 5057 5058 /* Symbol match routine common to both hash functions */ 5059 static bool 5060 matched_symbol(SymLook *req, const Obj_Entry *obj, Sym_Match_Result *result, 5061 const unsigned long symnum) 5062 { 5063 Elf_Versym verndx; 5064 const Elf_Sym *symp; 5065 const char *strp; 5066 5067 symp = obj->symtab + symnum; 5068 strp = obj->strtab + symp->st_name; 5069 5070 switch (ELF_ST_TYPE(symp->st_info)) { 5071 case STT_FUNC: 5072 case STT_NOTYPE: 5073 case STT_OBJECT: 5074 case STT_COMMON: 5075 case STT_GNU_IFUNC: 5076 if (symp->st_value == 0) 5077 return (false); 5078 /* fallthrough */ 5079 case STT_TLS: 5080 if (symp->st_shndx != SHN_UNDEF) 5081 break; 5082 else if (((req->flags & SYMLOOK_IN_PLT) == 0) && 5083 (ELF_ST_TYPE(symp->st_info) == STT_FUNC)) 5084 break; 5085 /* fallthrough */ 5086 default: 5087 return (false); 5088 } 5089 if (req->name[0] != strp[0] || strcmp(req->name, strp) != 0) 5090 return (false); 5091 5092 if (req->ventry == NULL) { 5093 if (obj->versyms != NULL) { 5094 verndx = VER_NDX(obj->versyms[symnum]); 5095 if (verndx > obj->vernum) { 5096 _rtld_error( 5097 "%s: symbol %s references wrong version %d", 5098 obj->path, obj->strtab + symnum, verndx); 5099 return (false); 5100 } 5101 /* 5102 * If we are not called from dlsym (i.e. this 5103 * is a normal relocation from unversioned 5104 * binary), accept the symbol immediately if 5105 * it happens to have first version after this 5106 * shared object became versioned. Otherwise, 5107 * if symbol is versioned and not hidden, 5108 * remember it. If it is the only symbol with 5109 * this name exported by the shared object, it 5110 * will be returned as a match by the calling 5111 * function. If symbol is global (verndx < 2) 5112 * accept it unconditionally. 5113 */ 5114 if ((req->flags & SYMLOOK_DLSYM) == 0 && 5115 verndx == VER_NDX_GIVEN) { 5116 result->sym_out = symp; 5117 return (true); 5118 } else if (verndx >= VER_NDX_GIVEN) { 5119 if ((obj->versyms[symnum] & VER_NDX_HIDDEN) == 5120 0) { 5121 if (result->vsymp == NULL) 5122 result->vsymp = symp; 5123 result->vcount++; 5124 } 5125 return (false); 5126 } 5127 } 5128 result->sym_out = symp; 5129 return (true); 5130 } 5131 if (obj->versyms == NULL) { 5132 if (object_match_name(obj, req->ventry->name)) { 5133 _rtld_error( 5134 "%s: object %s should provide version %s for symbol %s", 5135 obj_rtld.path, obj->path, req->ventry->name, 5136 obj->strtab + symnum); 5137 return (false); 5138 } 5139 } else { 5140 verndx = VER_NDX(obj->versyms[symnum]); 5141 if (verndx > obj->vernum) { 5142 _rtld_error("%s: symbol %s references wrong version %d", 5143 obj->path, obj->strtab + symnum, verndx); 5144 return (false); 5145 } 5146 if (obj->vertab[verndx].hash != req->ventry->hash || 5147 strcmp(obj->vertab[verndx].name, req->ventry->name)) { 5148 /* 5149 * Version does not match. Look if this is a 5150 * global symbol and if it is not hidden. If 5151 * global symbol (verndx < 2) is available, 5152 * use it. Do not return symbol if we are 5153 * called by dlvsym, because dlvsym looks for 5154 * a specific version and default one is not 5155 * what dlvsym wants. 5156 */ 5157 if ((req->flags & SYMLOOK_DLSYM) || 5158 (verndx >= VER_NDX_GIVEN) || 5159 (obj->versyms[symnum] & VER_NDX_HIDDEN)) 5160 return (false); 5161 } 5162 } 5163 result->sym_out = symp; 5164 return (true); 5165 } 5166 5167 /* 5168 * Search for symbol using SysV hash function. 5169 * obj->buckets is known not to be NULL at this point; the test for this was 5170 * performed with the obj->valid_hash_sysv assignment. 5171 */ 5172 static int 5173 symlook_obj1_sysv(SymLook *req, const Obj_Entry *obj) 5174 { 5175 unsigned long symnum; 5176 Sym_Match_Result matchres; 5177 5178 matchres.sym_out = NULL; 5179 matchres.vsymp = NULL; 5180 matchres.vcount = 0; 5181 5182 for (symnum = obj->buckets[req->hash % obj->nbuckets]; 5183 symnum != STN_UNDEF; symnum = obj->chains[symnum]) { 5184 if (symnum >= obj->nchains) 5185 return (ESRCH); /* Bad object */ 5186 5187 if (matched_symbol(req, obj, &matchres, symnum)) { 5188 req->sym_out = matchres.sym_out; 5189 req->defobj_out = obj; 5190 return (0); 5191 } 5192 } 5193 if (matchres.vcount == 1) { 5194 req->sym_out = matchres.vsymp; 5195 req->defobj_out = obj; 5196 return (0); 5197 } 5198 return (ESRCH); 5199 } 5200 5201 /* Search for symbol using GNU hash function */ 5202 static int 5203 symlook_obj1_gnu(SymLook *req, const Obj_Entry *obj) 5204 { 5205 Elf_Addr bloom_word; 5206 const Elf32_Word *hashval; 5207 Elf32_Word bucket; 5208 Sym_Match_Result matchres; 5209 unsigned int h1, h2; 5210 unsigned long symnum; 5211 5212 matchres.sym_out = NULL; 5213 matchres.vsymp = NULL; 5214 matchres.vcount = 0; 5215 5216 /* Pick right bitmask word from Bloom filter array */ 5217 bloom_word = obj->bloom_gnu[(req->hash_gnu / __ELF_WORD_SIZE) & 5218 obj->maskwords_bm_gnu]; 5219 5220 /* Calculate modulus word size of gnu hash and its derivative */ 5221 h1 = req->hash_gnu & (__ELF_WORD_SIZE - 1); 5222 h2 = ((req->hash_gnu >> obj->shift2_gnu) & (__ELF_WORD_SIZE - 1)); 5223 5224 /* Filter out the "definitely not in set" queries */ 5225 if (((bloom_word >> h1) & (bloom_word >> h2) & 1) == 0) 5226 return (ESRCH); 5227 5228 /* Locate hash chain and corresponding value element*/ 5229 bucket = obj->buckets_gnu[req->hash_gnu % obj->nbuckets_gnu]; 5230 if (bucket == 0) 5231 return (ESRCH); 5232 hashval = &obj->chain_zero_gnu[bucket]; 5233 do { 5234 if (((*hashval ^ req->hash_gnu) >> 1) == 0) { 5235 symnum = hashval - obj->chain_zero_gnu; 5236 if (matched_symbol(req, obj, &matchres, symnum)) { 5237 req->sym_out = matchres.sym_out; 5238 req->defobj_out = obj; 5239 return (0); 5240 } 5241 } 5242 } while ((*hashval++ & 1) == 0); 5243 if (matchres.vcount == 1) { 5244 req->sym_out = matchres.vsymp; 5245 req->defobj_out = obj; 5246 return (0); 5247 } 5248 return (ESRCH); 5249 } 5250 5251 static void 5252 trace_calc_fmts(const char **main_local, const char **fmt1, const char **fmt2) 5253 { 5254 *main_local = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_PROGNAME); 5255 if (*main_local == NULL) 5256 *main_local = ""; 5257 5258 *fmt1 = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_FMT1); 5259 if (*fmt1 == NULL) 5260 *fmt1 = "\t%o => %p (%x)\n"; 5261 5262 *fmt2 = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_FMT2); 5263 if (*fmt2 == NULL) 5264 *fmt2 = "\t%o (%x)\n"; 5265 } 5266 5267 static void 5268 trace_print_obj(Obj_Entry *obj, const char *name, const char *path, 5269 const char *main_local, const char *fmt1, const char *fmt2) 5270 { 5271 const char *fmt; 5272 int c; 5273 5274 if (fmt1 == NULL) 5275 fmt = fmt2; 5276 else 5277 /* XXX bogus */ 5278 fmt = strncmp(name, "lib", 3) == 0 ? fmt1 : fmt2; 5279 5280 while ((c = *fmt++) != '\0') { 5281 switch (c) { 5282 default: 5283 rtld_putchar(c); 5284 continue; 5285 case '\\': 5286 switch (c = *fmt) { 5287 case '\0': 5288 continue; 5289 case 'n': 5290 rtld_putchar('\n'); 5291 break; 5292 case 't': 5293 rtld_putchar('\t'); 5294 break; 5295 } 5296 break; 5297 case '%': 5298 switch (c = *fmt) { 5299 case '\0': 5300 continue; 5301 case '%': 5302 default: 5303 rtld_putchar(c); 5304 break; 5305 case 'A': 5306 rtld_putstr(main_local); 5307 break; 5308 case 'a': 5309 rtld_putstr(obj_main->path); 5310 break; 5311 case 'o': 5312 rtld_putstr(name); 5313 break; 5314 case 'p': 5315 rtld_putstr(path); 5316 break; 5317 case 'x': 5318 rtld_printf("%p", 5319 obj != NULL ? obj->mapbase : NULL); 5320 break; 5321 } 5322 break; 5323 } 5324 ++fmt; 5325 } 5326 } 5327 5328 static void 5329 trace_loaded_objects(Obj_Entry *obj, bool show_preload) 5330 { 5331 const char *fmt1, *fmt2, *main_local; 5332 const char *name, *path; 5333 bool first_spurious, list_containers; 5334 5335 trace_calc_fmts(&main_local, &fmt1, &fmt2); 5336 list_containers = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_ALL) != NULL; 5337 5338 for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 5339 Needed_Entry *needed; 5340 5341 if (obj->marker) 5342 continue; 5343 if (list_containers && obj->needed != NULL) 5344 rtld_printf("%s:\n", obj->path); 5345 for (needed = obj->needed; needed; needed = needed->next) { 5346 if (needed->obj != NULL) { 5347 if (needed->obj->traced && !list_containers) 5348 continue; 5349 needed->obj->traced = true; 5350 path = needed->obj->path; 5351 } else 5352 path = "not found"; 5353 5354 name = obj->strtab + needed->name; 5355 trace_print_obj(needed->obj, name, path, main_local, 5356 fmt1, fmt2); 5357 } 5358 } 5359 5360 if (show_preload) { 5361 if (ld_get_env_var(LD_TRACE_LOADED_OBJECTS_FMT2) == NULL) 5362 fmt2 = "\t%p (%x)\n"; 5363 first_spurious = true; 5364 5365 TAILQ_FOREACH(obj, &obj_list, next) { 5366 if (obj->marker || obj == obj_main || obj->traced) 5367 continue; 5368 5369 if (list_containers && first_spurious) { 5370 rtld_printf("[preloaded]\n"); 5371 first_spurious = false; 5372 } 5373 5374 Name_Entry *fname = STAILQ_FIRST(&obj->names); 5375 name = fname == NULL ? "<unknown>" : fname->name; 5376 trace_print_obj(obj, name, obj->path, main_local, NULL, 5377 fmt2); 5378 } 5379 } 5380 } 5381 5382 /* 5383 * Unload a dlopened object and its dependencies from memory and from 5384 * our data structures. It is assumed that the DAG rooted in the 5385 * object has already been unreferenced, and that the object has a 5386 * reference count of 0. 5387 */ 5388 static void 5389 unload_object(Obj_Entry *root, RtldLockState *lockstate) 5390 { 5391 Obj_Entry marker, *obj, *next; 5392 5393 assert(root->refcount == 0); 5394 5395 /* 5396 * Pass over the DAG removing unreferenced objects from 5397 * appropriate lists. 5398 */ 5399 unlink_object(root); 5400 5401 /* Unmap all objects that are no longer referenced. */ 5402 for (obj = TAILQ_FIRST(&obj_list); obj != NULL; obj = next) { 5403 next = TAILQ_NEXT(obj, next); 5404 if (obj->marker || obj->refcount != 0) 5405 continue; 5406 LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 5407 0, obj->path); 5408 dbg("unloading \"%s\"", obj->path); 5409 /* 5410 * Unlink the object now to prevent new references from 5411 * being acquired while the bind lock is dropped in 5412 * recursive dlclose() invocations. 5413 */ 5414 TAILQ_REMOVE(&obj_list, obj, next); 5415 obj_count--; 5416 5417 if (obj->filtees_loaded) { 5418 if (next != NULL) { 5419 init_marker(&marker); 5420 TAILQ_INSERT_BEFORE(next, &marker, next); 5421 unload_filtees(obj, lockstate); 5422 next = TAILQ_NEXT(&marker, next); 5423 TAILQ_REMOVE(&obj_list, &marker, next); 5424 } else 5425 unload_filtees(obj, lockstate); 5426 } 5427 release_object(obj); 5428 } 5429 } 5430 5431 static void 5432 unlink_object(Obj_Entry *root) 5433 { 5434 Objlist_Entry *elm; 5435 5436 if (root->refcount == 0) { 5437 /* Remove the object from the RTLD_GLOBAL list. */ 5438 objlist_remove(&list_global, root); 5439 5440 /* Remove the object from all objects' DAG lists. */ 5441 STAILQ_FOREACH(elm, &root->dagmembers, link) { 5442 objlist_remove(&elm->obj->dldags, root); 5443 if (elm->obj != root) 5444 unlink_object(elm->obj); 5445 } 5446 } 5447 } 5448 5449 static void 5450 ref_dag(Obj_Entry *root) 5451 { 5452 Objlist_Entry *elm; 5453 5454 assert(root->dag_inited); 5455 STAILQ_FOREACH(elm, &root->dagmembers, link) 5456 elm->obj->refcount++; 5457 } 5458 5459 static void 5460 unref_dag(Obj_Entry *root) 5461 { 5462 Objlist_Entry *elm; 5463 5464 assert(root->dag_inited); 5465 STAILQ_FOREACH(elm, &root->dagmembers, link) 5466 elm->obj->refcount--; 5467 } 5468 5469 /* 5470 * Common code for MD __tls_get_addr(). 5471 * 5472 * The tcb->tcb_dtv data structure is thread-local. The reason that 5473 * the function needs to take the rtld_bind_lock exclusive (as opposed 5474 * to only shared, to safely access obj_list in allocate_module_tls()) 5475 * is to protect the rtld_malloc data. 5476 */ 5477 static void * 5478 tls_get_addr_slow(struct tcb *tcb, int index, size_t offset, bool locked) 5479 { 5480 struct dtv *newdtv, *dtv; 5481 RtldLockState lockstate; 5482 int to_copy; 5483 5484 dtv = tcb->tcb_dtv; 5485 /* Check dtv generation in case new modules have arrived */ 5486 if (dtv->dtv_gen != tls_dtv_generation) { 5487 if (!locked) 5488 wlock_acquire(rtld_bind_lock, &lockstate); 5489 newdtv = xcalloc(1, sizeof(struct dtv) + tls_max_index * 5490 sizeof(struct dtv_slot)); 5491 to_copy = dtv->dtv_size; 5492 if (to_copy > tls_max_index) 5493 to_copy = tls_max_index; 5494 memcpy(newdtv->dtv_slots, dtv->dtv_slots, to_copy * 5495 sizeof(struct dtv_slot)); 5496 newdtv->dtv_gen = tls_dtv_generation; 5497 newdtv->dtv_size = tls_max_index; 5498 free(dtv); 5499 if (!locked) 5500 lock_release(rtld_bind_lock, &lockstate); 5501 dtv = tcb->tcb_dtv = newdtv; 5502 } 5503 5504 /* Dynamically allocate module TLS if necessary */ 5505 if (dtv->dtv_slots[index - 1].dtvs_tls == 0) { 5506 /* Signal safe, wlock will block out signals. */ 5507 if (!locked) 5508 wlock_acquire(rtld_bind_lock, &lockstate); 5509 if (!dtv->dtv_slots[index - 1].dtvs_tls) 5510 dtv->dtv_slots[index - 1].dtvs_tls = 5511 allocate_module_tls(tcb, index); 5512 if (!locked) 5513 lock_release(rtld_bind_lock, &lockstate); 5514 } 5515 return (dtv->dtv_slots[index - 1].dtvs_tls + offset); 5516 } 5517 5518 void * 5519 tls_get_addr_common(struct tcb *tcb, int index, size_t offset) 5520 { 5521 struct dtv *dtv; 5522 5523 dtv = tcb->tcb_dtv; 5524 /* Check dtv generation in case new modules have arrived */ 5525 if (__predict_true(dtv->dtv_gen == tls_dtv_generation && 5526 dtv->dtv_slots[index - 1].dtvs_tls != 0)) 5527 return (dtv->dtv_slots[index - 1].dtvs_tls + offset); 5528 return (tls_get_addr_slow(tcb, index, offset, false)); 5529 } 5530 5531 static struct tcb * 5532 tcb_from_tcb_list_entry(struct tcb_list_entry *tcbelm) 5533 { 5534 #ifdef TLS_VARIANT_I 5535 return ((struct tcb *)((char *)tcbelm - tcb_list_entry_offset)); 5536 #else 5537 return ((struct tcb *)((char *)tcbelm + tcb_list_entry_offset)); 5538 #endif 5539 } 5540 5541 static struct tcb_list_entry * 5542 tcb_list_entry_from_tcb(struct tcb *tcb) 5543 { 5544 #ifdef TLS_VARIANT_I 5545 return ((struct tcb_list_entry *)((char *)tcb + tcb_list_entry_offset)); 5546 #else 5547 return ((struct tcb_list_entry *)((char *)tcb - tcb_list_entry_offset)); 5548 #endif 5549 } 5550 5551 static void 5552 tcb_list_insert(struct tcb *tcb) 5553 { 5554 struct tcb_list_entry *tcbelm; 5555 5556 tcbelm = tcb_list_entry_from_tcb(tcb); 5557 TAILQ_INSERT_TAIL(&tcb_list, tcbelm, next); 5558 } 5559 5560 static void 5561 tcb_list_remove(struct tcb *tcb) 5562 { 5563 struct tcb_list_entry *tcbelm; 5564 5565 tcbelm = tcb_list_entry_from_tcb(tcb); 5566 TAILQ_REMOVE(&tcb_list, tcbelm, next); 5567 } 5568 5569 #ifdef TLS_VARIANT_I 5570 5571 /* 5572 * Return pointer to allocated TLS block 5573 */ 5574 static void * 5575 get_tls_block_ptr(void *tcb, size_t tcbsize) 5576 { 5577 size_t extra_size, post_size, pre_size, tls_block_size; 5578 size_t tls_init_align; 5579 5580 tls_init_align = MAX(obj_main->tlsalign, 1); 5581 5582 /* Compute fragments sizes. */ 5583 extra_size = tcbsize - TLS_TCB_SIZE; 5584 post_size = calculate_tls_post_size(tls_init_align); 5585 tls_block_size = tcbsize + post_size; 5586 pre_size = roundup2(tls_block_size, tls_init_align) - tls_block_size; 5587 5588 return ((char *)tcb - pre_size - extra_size); 5589 } 5590 5591 /* 5592 * Allocate Static TLS using the Variant I method. 5593 * 5594 * For details on the layout, see lib/libc/gen/tls.c. 5595 * 5596 * NB: rtld's tls_static_space variable includes TLS_TCB_SIZE and post_size as 5597 * it is based on tls_last_offset, and TLS offsets here are really TCB 5598 * offsets, whereas libc's tls_static_space is just the executable's static 5599 * TLS segment. 5600 * 5601 * NB: This differs from NetBSD's ld.elf_so, where TLS offsets are relative to 5602 * the end of the TCB. 5603 */ 5604 void * 5605 allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign) 5606 { 5607 Obj_Entry *obj; 5608 char *tls_block; 5609 struct dtv *dtv; 5610 struct tcb *tcb; 5611 char *addr; 5612 size_t i; 5613 size_t extra_size, maxalign, post_size, pre_size, tls_block_size; 5614 size_t tls_init_align, tls_init_offset, tls_bss_offset; 5615 5616 if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE) 5617 return (oldtcb); 5618 5619 assert(tcbsize >= TLS_TCB_SIZE); 5620 maxalign = MAX(tcbalign, tls_static_max_align); 5621 tls_init_align = MAX(obj_main->tlsalign, 1); 5622 5623 /* Compute fragments sizes. */ 5624 extra_size = tcbsize - TLS_TCB_SIZE; 5625 post_size = calculate_tls_post_size(tls_init_align); 5626 tls_block_size = tcbsize + post_size; 5627 pre_size = roundup2(tls_block_size, tls_init_align) - tls_block_size; 5628 tls_block_size += pre_size + tls_static_space - TLS_TCB_SIZE - 5629 post_size; 5630 5631 /* Allocate whole TLS block */ 5632 tls_block = xmalloc_aligned(tls_block_size, maxalign, 0); 5633 tcb = (struct tcb *)(tls_block + pre_size + extra_size); 5634 5635 if (oldtcb != NULL) { 5636 memcpy(tls_block, get_tls_block_ptr(oldtcb, tcbsize), 5637 tls_static_space); 5638 free(get_tls_block_ptr(oldtcb, tcbsize)); 5639 5640 /* Adjust the DTV. */ 5641 dtv = tcb->tcb_dtv; 5642 for (i = 0; i < dtv->dtv_size; i++) { 5643 if ((uintptr_t)dtv->dtv_slots[i].dtvs_tls >= 5644 (uintptr_t)oldtcb && 5645 (uintptr_t)dtv->dtv_slots[i].dtvs_tls < 5646 (uintptr_t)oldtcb + tls_static_space) { 5647 dtv->dtv_slots[i].dtvs_tls = (char *)tcb + 5648 (dtv->dtv_slots[i].dtvs_tls - 5649 (char *)oldtcb); 5650 } 5651 } 5652 } else { 5653 dtv = xcalloc(1, sizeof(struct dtv) + tls_max_index * 5654 sizeof(struct dtv_slot)); 5655 tcb->tcb_dtv = dtv; 5656 dtv->dtv_gen = tls_dtv_generation; 5657 dtv->dtv_size = tls_max_index; 5658 5659 for (obj = globallist_curr(objs); obj != NULL; 5660 obj = globallist_next(obj)) { 5661 if (obj->tlsoffset == 0) 5662 continue; 5663 tls_init_offset = obj->tlspoffset & (obj->tlsalign - 1); 5664 addr = (char *)tcb + obj->tlsoffset; 5665 if (tls_init_offset > 0) 5666 memset(addr, 0, tls_init_offset); 5667 if (obj->tlsinitsize > 0) { 5668 memcpy(addr + tls_init_offset, obj->tlsinit, 5669 obj->tlsinitsize); 5670 } 5671 if (obj->tlssize > obj->tlsinitsize) { 5672 tls_bss_offset = tls_init_offset + 5673 obj->tlsinitsize; 5674 memset(addr + tls_bss_offset, 0, 5675 obj->tlssize - tls_bss_offset); 5676 } 5677 dtv->dtv_slots[obj->tlsindex - 1].dtvs_tls = addr; 5678 } 5679 } 5680 5681 tcb_list_insert(tcb); 5682 return (tcb); 5683 } 5684 5685 void 5686 free_tls(void *tcb, size_t tcbsize, size_t tcbalign __unused) 5687 { 5688 struct dtv *dtv; 5689 uintptr_t tlsstart, tlsend; 5690 size_t post_size; 5691 size_t i, tls_init_align __unused; 5692 5693 tcb_list_remove(tcb); 5694 5695 assert(tcbsize >= TLS_TCB_SIZE); 5696 tls_init_align = MAX(obj_main->tlsalign, 1); 5697 5698 /* Compute fragments sizes. */ 5699 post_size = calculate_tls_post_size(tls_init_align); 5700 5701 tlsstart = (uintptr_t)tcb + TLS_TCB_SIZE + post_size; 5702 tlsend = (uintptr_t)tcb + tls_static_space; 5703 5704 dtv = ((struct tcb *)tcb)->tcb_dtv; 5705 for (i = 0; i < dtv->dtv_size; i++) { 5706 if (dtv->dtv_slots[i].dtvs_tls != NULL && 5707 ((uintptr_t)dtv->dtv_slots[i].dtvs_tls < tlsstart || 5708 (uintptr_t)dtv->dtv_slots[i].dtvs_tls >= tlsend)) { 5709 free(dtv->dtv_slots[i].dtvs_tls); 5710 } 5711 } 5712 free(dtv); 5713 free(get_tls_block_ptr(tcb, tcbsize)); 5714 } 5715 5716 #endif /* TLS_VARIANT_I */ 5717 5718 #ifdef TLS_VARIANT_II 5719 5720 /* 5721 * Allocate Static TLS using the Variant II method. 5722 */ 5723 void * 5724 allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign) 5725 { 5726 Obj_Entry *obj; 5727 size_t size, ralign; 5728 char *tls_block; 5729 struct dtv *dtv, *olddtv; 5730 struct tcb *tcb; 5731 char *addr; 5732 size_t i; 5733 5734 ralign = tcbalign; 5735 if (tls_static_max_align > ralign) 5736 ralign = tls_static_max_align; 5737 size = roundup(tls_static_space, ralign) + roundup(tcbsize, ralign); 5738 5739 assert(tcbsize >= 2 * sizeof(uintptr_t)); 5740 tls_block = xmalloc_aligned(size, ralign, 0 /* XXX */); 5741 dtv = xcalloc(1, sizeof(struct dtv) + tls_max_index * 5742 sizeof(struct dtv_slot)); 5743 5744 tcb = (struct tcb *)(tls_block + roundup(tls_static_space, ralign)); 5745 tcb->tcb_self = tcb; 5746 tcb->tcb_dtv = dtv; 5747 5748 dtv->dtv_gen = tls_dtv_generation; 5749 dtv->dtv_size = tls_max_index; 5750 5751 if (oldtcb != NULL) { 5752 /* 5753 * Copy the static TLS block over whole. 5754 */ 5755 memcpy((char *)tcb - tls_static_space, 5756 (const char *)oldtcb - tls_static_space, 5757 tls_static_space); 5758 5759 /* 5760 * If any dynamic TLS blocks have been created tls_get_addr(), 5761 * move them over. 5762 */ 5763 olddtv = ((struct tcb *)oldtcb)->tcb_dtv; 5764 for (i = 0; i < olddtv->dtv_size; i++) { 5765 if ((uintptr_t)olddtv->dtv_slots[i].dtvs_tls < 5766 (uintptr_t)oldtcb - size || 5767 (uintptr_t)olddtv->dtv_slots[i].dtvs_tls > 5768 (uintptr_t)oldtcb) { 5769 dtv->dtv_slots[i].dtvs_tls = 5770 olddtv->dtv_slots[i].dtvs_tls; 5771 olddtv->dtv_slots[i].dtvs_tls = NULL; 5772 } 5773 } 5774 5775 /* 5776 * We assume that this block was the one we created with 5777 * allocate_initial_tls(). 5778 */ 5779 free_tls(oldtcb, 2 * sizeof(uintptr_t), sizeof(uintptr_t)); 5780 } else { 5781 for (obj = objs; obj != NULL; obj = TAILQ_NEXT(obj, next)) { 5782 if (obj->marker || obj->tlsoffset == 0) 5783 continue; 5784 addr = (char *)tcb - obj->tlsoffset; 5785 memset(addr + obj->tlsinitsize, 0, obj->tlssize - 5786 obj->tlsinitsize); 5787 if (obj->tlsinit) { 5788 memcpy(addr, obj->tlsinit, obj->tlsinitsize); 5789 obj->static_tls_copied = true; 5790 } 5791 dtv->dtv_slots[obj->tlsindex - 1].dtvs_tls = addr; 5792 } 5793 } 5794 5795 tcb_list_insert(tcb); 5796 return (tcb); 5797 } 5798 5799 void 5800 free_tls(void *tcb, size_t tcbsize __unused, size_t tcbalign) 5801 { 5802 struct dtv *dtv; 5803 size_t size, ralign; 5804 size_t i; 5805 uintptr_t tlsstart, tlsend; 5806 5807 tcb_list_remove(tcb); 5808 5809 /* 5810 * Figure out the size of the initial TLS block so that we can 5811 * find stuff which ___tls_get_addr() allocated dynamically. 5812 */ 5813 ralign = tcbalign; 5814 if (tls_static_max_align > ralign) 5815 ralign = tls_static_max_align; 5816 size = roundup(tls_static_space, ralign); 5817 5818 dtv = ((struct tcb *)tcb)->tcb_dtv; 5819 tlsend = (uintptr_t)tcb; 5820 tlsstart = tlsend - size; 5821 for (i = 0; i < dtv->dtv_size; i++) { 5822 if (dtv->dtv_slots[i].dtvs_tls != NULL && 5823 ((uintptr_t)dtv->dtv_slots[i].dtvs_tls < tlsstart || 5824 (uintptr_t)dtv->dtv_slots[i].dtvs_tls > tlsend)) { 5825 free(dtv->dtv_slots[i].dtvs_tls); 5826 } 5827 } 5828 5829 free((void *)tlsstart); 5830 free(dtv); 5831 } 5832 5833 #endif /* TLS_VARIANT_II */ 5834 5835 /* 5836 * Allocate TLS block for module with given index. 5837 */ 5838 void * 5839 allocate_module_tls(struct tcb *tcb, int index) 5840 { 5841 Obj_Entry *obj; 5842 char *p; 5843 5844 TAILQ_FOREACH(obj, &obj_list, next) { 5845 if (obj->marker) 5846 continue; 5847 if (obj->tlsindex == index) 5848 break; 5849 } 5850 if (obj == NULL) { 5851 _rtld_error("Can't find module with TLS index %d", index); 5852 rtld_die(); 5853 } 5854 5855 if (obj->tls_static) { 5856 #ifdef TLS_VARIANT_I 5857 p = (char *)tcb + obj->tlsoffset; 5858 #else 5859 p = (char *)tcb - obj->tlsoffset; 5860 #endif 5861 return (p); 5862 } 5863 5864 obj->tls_dynamic = true; 5865 5866 p = xmalloc_aligned(obj->tlssize, obj->tlsalign, obj->tlspoffset); 5867 memcpy(p, obj->tlsinit, obj->tlsinitsize); 5868 memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize); 5869 return (p); 5870 } 5871 5872 static bool 5873 allocate_tls_offset_common(size_t *offp, size_t tlssize, size_t tlsalign, 5874 size_t tlspoffset __unused) 5875 { 5876 size_t off; 5877 5878 if (tls_last_offset == 0) 5879 off = calculate_first_tls_offset(tlssize, tlsalign, 5880 tlspoffset); 5881 else 5882 off = calculate_tls_offset(tls_last_offset, tls_last_size, 5883 tlssize, tlsalign, tlspoffset); 5884 5885 *offp = off; 5886 #ifdef TLS_VARIANT_I 5887 off += tlssize; 5888 #endif 5889 5890 /* 5891 * If we have already fixed the size of the static TLS block, we 5892 * must stay within that size. When allocating the static TLS, we 5893 * leave a small amount of space spare to be used for dynamically 5894 * loading modules which use static TLS. 5895 */ 5896 if (tls_static_space != 0) { 5897 if (off > tls_static_space) 5898 return (false); 5899 } else if (tlsalign > tls_static_max_align) { 5900 tls_static_max_align = tlsalign; 5901 } 5902 5903 tls_last_offset = off; 5904 tls_last_size = tlssize; 5905 5906 return (true); 5907 } 5908 5909 bool 5910 allocate_tls_offset(Obj_Entry *obj) 5911 { 5912 if (obj->tls_dynamic) 5913 return (false); 5914 5915 if (obj->tls_static) 5916 return (true); 5917 5918 if (obj->tlssize == 0) { 5919 obj->tls_static = true; 5920 return (true); 5921 } 5922 5923 if (!allocate_tls_offset_common(&obj->tlsoffset, obj->tlssize, 5924 obj->tlsalign, obj->tlspoffset)) 5925 return (false); 5926 5927 obj->tls_static = true; 5928 5929 return (true); 5930 } 5931 5932 void 5933 free_tls_offset(Obj_Entry *obj) 5934 { 5935 /* 5936 * If we were the last thing to allocate out of the static TLS 5937 * block, we give our space back to the 'allocator'. This is a 5938 * simplistic workaround to allow libGL.so.1 to be loaded and 5939 * unloaded multiple times. 5940 */ 5941 size_t off = obj->tlsoffset; 5942 5943 #ifdef TLS_VARIANT_I 5944 off += obj->tlssize; 5945 #endif 5946 if (off == tls_last_offset) { 5947 tls_last_offset -= obj->tlssize; 5948 tls_last_size = 0; 5949 } 5950 } 5951 5952 void * 5953 _rtld_allocate_tls(void *oldtcb, size_t tcbsize, size_t tcbalign) 5954 { 5955 void *ret; 5956 RtldLockState lockstate; 5957 5958 wlock_acquire(rtld_bind_lock, &lockstate); 5959 ret = allocate_tls(globallist_curr(TAILQ_FIRST(&obj_list)), oldtcb, 5960 tcbsize, tcbalign); 5961 lock_release(rtld_bind_lock, &lockstate); 5962 return (ret); 5963 } 5964 5965 void 5966 _rtld_free_tls(void *tcb, size_t tcbsize, size_t tcbalign) 5967 { 5968 RtldLockState lockstate; 5969 5970 wlock_acquire(rtld_bind_lock, &lockstate); 5971 free_tls(tcb, tcbsize, tcbalign); 5972 lock_release(rtld_bind_lock, &lockstate); 5973 } 5974 5975 static void 5976 object_add_name(Obj_Entry *obj, const char *name) 5977 { 5978 Name_Entry *entry; 5979 size_t len; 5980 5981 len = strlen(name); 5982 entry = malloc(sizeof(Name_Entry) + len); 5983 5984 if (entry != NULL) { 5985 strcpy(entry->name, name); 5986 STAILQ_INSERT_TAIL(&obj->names, entry, link); 5987 } 5988 } 5989 5990 static int 5991 object_match_name(const Obj_Entry *obj, const char *name) 5992 { 5993 Name_Entry *entry; 5994 5995 STAILQ_FOREACH(entry, &obj->names, link) { 5996 if (strcmp(name, entry->name) == 0) 5997 return (1); 5998 } 5999 return (0); 6000 } 6001 6002 static Obj_Entry * 6003 locate_dependency(const Obj_Entry *obj, const char *name) 6004 { 6005 const Objlist_Entry *entry; 6006 const Needed_Entry *needed; 6007 6008 STAILQ_FOREACH(entry, &list_main, link) { 6009 if (object_match_name(entry->obj, name)) 6010 return (entry->obj); 6011 } 6012 6013 for (needed = obj->needed; needed != NULL; needed = needed->next) { 6014 if (strcmp(obj->strtab + needed->name, name) == 0 || 6015 (needed->obj != NULL && object_match_name(needed->obj, 6016 name))) { 6017 /* 6018 * If there is DT_NEEDED for the name we are looking 6019 * for, we are all set. Note that object might not be 6020 * found if dependency was not loaded yet, so the 6021 * function can return NULL here. This is expected and 6022 * handled properly by the caller. 6023 */ 6024 return (needed->obj); 6025 } 6026 } 6027 _rtld_error("%s: Unexpected inconsistency: dependency %s not found", 6028 obj->path, name); 6029 rtld_die(); 6030 } 6031 6032 static int 6033 check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj, 6034 const Elf_Vernaux *vna) 6035 { 6036 const Elf_Verdef *vd; 6037 const char *vername; 6038 6039 vername = refobj->strtab + vna->vna_name; 6040 vd = depobj->verdef; 6041 if (vd == NULL) { 6042 _rtld_error("%s: version %s required by %s not defined", 6043 depobj->path, vername, refobj->path); 6044 return (-1); 6045 } 6046 for (;;) { 6047 if (vd->vd_version != VER_DEF_CURRENT) { 6048 _rtld_error( 6049 "%s: Unsupported version %d of Elf_Verdef entry", 6050 depobj->path, vd->vd_version); 6051 return (-1); 6052 } 6053 if (vna->vna_hash == vd->vd_hash) { 6054 const Elf_Verdaux *aux = 6055 (const Elf_Verdaux *)((const char *)vd + 6056 vd->vd_aux); 6057 if (strcmp(vername, depobj->strtab + aux->vda_name) == 6058 0) 6059 return (0); 6060 } 6061 if (vd->vd_next == 0) 6062 break; 6063 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 6064 } 6065 if (vna->vna_flags & VER_FLG_WEAK) 6066 return (0); 6067 _rtld_error("%s: version %s required by %s not found", depobj->path, 6068 vername, refobj->path); 6069 return (-1); 6070 } 6071 6072 static int 6073 rtld_verify_object_versions(Obj_Entry *obj) 6074 { 6075 const Elf_Verneed *vn; 6076 const Elf_Verdef *vd; 6077 const Elf_Verdaux *vda; 6078 const Elf_Vernaux *vna; 6079 const Obj_Entry *depobj; 6080 int maxvernum, vernum; 6081 6082 if (obj->ver_checked) 6083 return (0); 6084 obj->ver_checked = true; 6085 6086 maxvernum = 0; 6087 /* 6088 * Walk over defined and required version records and figure out 6089 * max index used by any of them. Do very basic sanity checking 6090 * while there. 6091 */ 6092 vn = obj->verneed; 6093 while (vn != NULL) { 6094 if (vn->vn_version != VER_NEED_CURRENT) { 6095 _rtld_error( 6096 "%s: Unsupported version %d of Elf_Verneed entry", 6097 obj->path, vn->vn_version); 6098 return (-1); 6099 } 6100 vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux); 6101 for (;;) { 6102 vernum = VER_NEED_IDX(vna->vna_other); 6103 if (vernum > maxvernum) 6104 maxvernum = vernum; 6105 if (vna->vna_next == 0) 6106 break; 6107 vna = (const Elf_Vernaux *)((const char *)vna + 6108 vna->vna_next); 6109 } 6110 if (vn->vn_next == 0) 6111 break; 6112 vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next); 6113 } 6114 6115 vd = obj->verdef; 6116 while (vd != NULL) { 6117 if (vd->vd_version != VER_DEF_CURRENT) { 6118 _rtld_error( 6119 "%s: Unsupported version %d of Elf_Verdef entry", 6120 obj->path, vd->vd_version); 6121 return (-1); 6122 } 6123 vernum = VER_DEF_IDX(vd->vd_ndx); 6124 if (vernum > maxvernum) 6125 maxvernum = vernum; 6126 if (vd->vd_next == 0) 6127 break; 6128 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 6129 } 6130 6131 if (maxvernum == 0) 6132 return (0); 6133 6134 /* 6135 * Store version information in array indexable by version index. 6136 * Verify that object version requirements are satisfied along the 6137 * way. 6138 */ 6139 obj->vernum = maxvernum + 1; 6140 obj->vertab = xcalloc(obj->vernum, sizeof(Ver_Entry)); 6141 6142 vd = obj->verdef; 6143 while (vd != NULL) { 6144 if ((vd->vd_flags & VER_FLG_BASE) == 0) { 6145 vernum = VER_DEF_IDX(vd->vd_ndx); 6146 assert(vernum <= maxvernum); 6147 vda = (const Elf_Verdaux *)((const char *)vd + 6148 vd->vd_aux); 6149 obj->vertab[vernum].hash = vd->vd_hash; 6150 obj->vertab[vernum].name = obj->strtab + vda->vda_name; 6151 obj->vertab[vernum].file = NULL; 6152 obj->vertab[vernum].flags = 0; 6153 } 6154 if (vd->vd_next == 0) 6155 break; 6156 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next); 6157 } 6158 6159 vn = obj->verneed; 6160 while (vn != NULL) { 6161 depobj = locate_dependency(obj, obj->strtab + vn->vn_file); 6162 if (depobj == NULL) 6163 return (-1); 6164 vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux); 6165 for (;;) { 6166 if (check_object_provided_version(obj, depobj, vna)) 6167 return (-1); 6168 vernum = VER_NEED_IDX(vna->vna_other); 6169 assert(vernum <= maxvernum); 6170 obj->vertab[vernum].hash = vna->vna_hash; 6171 obj->vertab[vernum].name = obj->strtab + vna->vna_name; 6172 obj->vertab[vernum].file = obj->strtab + vn->vn_file; 6173 obj->vertab[vernum].flags = (vna->vna_other & 6174 VER_NEED_HIDDEN) != 0 ? VER_INFO_HIDDEN : 0; 6175 if (vna->vna_next == 0) 6176 break; 6177 vna = (const Elf_Vernaux *)((const char *)vna + 6178 vna->vna_next); 6179 } 6180 if (vn->vn_next == 0) 6181 break; 6182 vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next); 6183 } 6184 return (0); 6185 } 6186 6187 static int 6188 rtld_verify_versions(const Objlist *objlist) 6189 { 6190 Objlist_Entry *entry; 6191 int rc; 6192 6193 rc = 0; 6194 STAILQ_FOREACH(entry, objlist, link) { 6195 /* 6196 * Skip dummy objects or objects that have their version 6197 * requirements already checked. 6198 */ 6199 if (entry->obj->strtab == NULL || entry->obj->vertab != NULL) 6200 continue; 6201 if (rtld_verify_object_versions(entry->obj) == -1) { 6202 rc = -1; 6203 if (ld_tracing == NULL) 6204 break; 6205 } 6206 } 6207 if (rc == 0 || ld_tracing != NULL) 6208 rc = rtld_verify_object_versions(&obj_rtld); 6209 return (rc); 6210 } 6211 6212 const Ver_Entry * 6213 fetch_ventry(const Obj_Entry *obj, unsigned long symnum) 6214 { 6215 Elf_Versym vernum; 6216 6217 if (obj->vertab) { 6218 vernum = VER_NDX(obj->versyms[symnum]); 6219 if (vernum >= obj->vernum) { 6220 _rtld_error("%s: symbol %s has wrong verneed value %d", 6221 obj->path, obj->strtab + symnum, vernum); 6222 } else if (obj->vertab[vernum].hash != 0) { 6223 return (&obj->vertab[vernum]); 6224 } 6225 } 6226 return (NULL); 6227 } 6228 6229 int 6230 _rtld_get_stack_prot(void) 6231 { 6232 return (stack_prot); 6233 } 6234 6235 int 6236 _rtld_is_dlopened(void *arg) 6237 { 6238 Obj_Entry *obj; 6239 RtldLockState lockstate; 6240 int res; 6241 6242 rlock_acquire(rtld_bind_lock, &lockstate); 6243 obj = dlcheck(arg); 6244 if (obj == NULL) 6245 obj = obj_from_addr(arg); 6246 if (obj == NULL) { 6247 _rtld_error("No shared object contains address"); 6248 lock_release(rtld_bind_lock, &lockstate); 6249 return (-1); 6250 } 6251 res = obj->dlopened ? 1 : 0; 6252 lock_release(rtld_bind_lock, &lockstate); 6253 return (res); 6254 } 6255 6256 static int 6257 obj_remap_relro(Obj_Entry *obj, int prot) 6258 { 6259 const Elf_Phdr *ph; 6260 caddr_t relro_page; 6261 size_t relro_size; 6262 6263 for (ph = obj->phdr; ph < obj->phdr + obj->phnum; ph++) { 6264 if (ph->p_type != PT_GNU_RELRO) 6265 continue; 6266 relro_page = obj->relocbase + rtld_trunc_page(ph->p_vaddr); 6267 relro_size = rtld_round_page(ph->p_vaddr + ph->p_memsz) - 6268 rtld_trunc_page(ph->p_vaddr); 6269 if (mprotect(relro_page, relro_size, prot) == -1) { 6270 _rtld_error( 6271 "%s: Cannot set relro protection to %#x: %s", 6272 obj->path, prot, rtld_strerror(errno)); 6273 return (-1); 6274 } 6275 break; 6276 } 6277 return (0); 6278 } 6279 6280 static int 6281 obj_disable_relro(Obj_Entry *obj) 6282 { 6283 return (obj_remap_relro(obj, PROT_READ | PROT_WRITE)); 6284 } 6285 6286 static int 6287 obj_enforce_relro(Obj_Entry *obj) 6288 { 6289 return (obj_remap_relro(obj, PROT_READ)); 6290 } 6291 6292 static void 6293 map_stacks_exec(RtldLockState *lockstate) 6294 { 6295 void (*thr_map_stacks_exec)(void); 6296 6297 if ((max_stack_flags & PF_X) == 0 || (stack_prot & PROT_EXEC) != 0) 6298 return; 6299 thr_map_stacks_exec = (void (*)(void))( 6300 uintptr_t)get_program_var_addr("__pthread_map_stacks_exec", 6301 lockstate); 6302 if (thr_map_stacks_exec != NULL) { 6303 stack_prot |= PROT_EXEC; 6304 thr_map_stacks_exec(); 6305 } 6306 } 6307 6308 static void 6309 distribute_static_tls(Objlist *list) 6310 { 6311 struct tcb_list_entry *tcbelm; 6312 Objlist_Entry *objelm; 6313 struct tcb *tcb; 6314 Obj_Entry *obj; 6315 char *tlsbase; 6316 6317 STAILQ_FOREACH(objelm, list, link) { 6318 obj = objelm->obj; 6319 if (obj->marker || !obj->tls_static || obj->static_tls_copied) 6320 continue; 6321 TAILQ_FOREACH(tcbelm, &tcb_list, next) { 6322 tcb = tcb_from_tcb_list_entry(tcbelm); 6323 #ifdef TLS_VARIANT_I 6324 tlsbase = (char *)tcb + obj->tlsoffset; 6325 #else 6326 tlsbase = (char *)tcb - obj->tlsoffset; 6327 #endif 6328 memcpy(tlsbase, obj->tlsinit, obj->tlsinitsize); 6329 memset(tlsbase + obj->tlsinitsize, 0, 6330 obj->tlssize - obj->tlsinitsize); 6331 } 6332 obj->static_tls_copied = true; 6333 } 6334 } 6335 6336 void 6337 symlook_init(SymLook *dst, const char *name) 6338 { 6339 bzero(dst, sizeof(*dst)); 6340 dst->name = name; 6341 dst->hash = elf_hash(name); 6342 dst->hash_gnu = gnu_hash(name); 6343 } 6344 6345 static void 6346 symlook_init_from_req(SymLook *dst, const SymLook *src) 6347 { 6348 dst->name = src->name; 6349 dst->hash = src->hash; 6350 dst->hash_gnu = src->hash_gnu; 6351 dst->ventry = src->ventry; 6352 dst->flags = src->flags; 6353 dst->defobj_out = NULL; 6354 dst->sym_out = NULL; 6355 dst->lockstate = src->lockstate; 6356 dst->donelist_mem = NULL; 6357 } 6358 6359 static int 6360 open_binary_fd(const char *argv0, bool search_in_path, const char **binpath_res) 6361 { 6362 char *binpath, *pathenv, *pe, *res1; 6363 const char *res; 6364 int fd; 6365 6366 binpath = NULL; 6367 res = NULL; 6368 if (search_in_path && strchr(argv0, '/') == NULL) { 6369 binpath = xmalloc(PATH_MAX); 6370 pathenv = getenv("PATH"); 6371 if (pathenv == NULL) { 6372 _rtld_error("-p and no PATH environment variable"); 6373 rtld_die(); 6374 } 6375 pathenv = strdup(pathenv); 6376 if (pathenv == NULL) { 6377 _rtld_error("Cannot allocate memory"); 6378 rtld_die(); 6379 } 6380 fd = -1; 6381 errno = ENOENT; 6382 while ((pe = strsep(&pathenv, ":")) != NULL) { 6383 if (strlcpy(binpath, pe, PATH_MAX) >= PATH_MAX) 6384 continue; 6385 if (binpath[0] != '\0' && 6386 strlcat(binpath, "/", PATH_MAX) >= PATH_MAX) 6387 continue; 6388 if (strlcat(binpath, argv0, PATH_MAX) >= PATH_MAX) 6389 continue; 6390 fd = open(binpath, O_RDONLY | O_CLOEXEC | O_VERIFY); 6391 if (fd != -1 || errno != ENOENT) { 6392 res = binpath; 6393 break; 6394 } 6395 } 6396 free(pathenv); 6397 } else { 6398 fd = open(argv0, O_RDONLY | O_CLOEXEC | O_VERIFY); 6399 res = argv0; 6400 } 6401 6402 if (fd == -1) { 6403 _rtld_error("Cannot open %s: %s", argv0, rtld_strerror(errno)); 6404 rtld_die(); 6405 } 6406 if (res != NULL && res[0] != '/') { 6407 res1 = xmalloc(PATH_MAX); 6408 if (realpath(res, res1) != NULL) { 6409 if (res != argv0) 6410 free(__DECONST(char *, res)); 6411 res = res1; 6412 } else { 6413 free(res1); 6414 } 6415 } 6416 *binpath_res = res; 6417 return (fd); 6418 } 6419 6420 /* 6421 * Parse a set of command-line arguments. 6422 */ 6423 static int 6424 parse_args(char *argv[], int argc, bool *use_pathp, int *fdp, 6425 const char **argv0, bool *dir_ignore) 6426 { 6427 const char *arg; 6428 char machine[64]; 6429 size_t sz; 6430 int arglen, fd, i, j, mib[2]; 6431 char opt; 6432 bool seen_b, seen_f; 6433 6434 dbg("Parsing command-line arguments"); 6435 *use_pathp = false; 6436 *fdp = -1; 6437 *dir_ignore = false; 6438 seen_b = seen_f = false; 6439 6440 for (i = 1; i < argc; i++) { 6441 arg = argv[i]; 6442 dbg("argv[%d]: '%s'", i, arg); 6443 6444 /* 6445 * rtld arguments end with an explicit "--" or with the first 6446 * non-prefixed argument. 6447 */ 6448 if (strcmp(arg, "--") == 0) { 6449 i++; 6450 break; 6451 } 6452 if (arg[0] != '-') 6453 break; 6454 6455 /* 6456 * All other arguments are single-character options that can 6457 * be combined, so we need to search through `arg` for them. 6458 */ 6459 arglen = strlen(arg); 6460 for (j = 1; j < arglen; j++) { 6461 opt = arg[j]; 6462 if (opt == 'h') { 6463 print_usage(argv[0]); 6464 _exit(0); 6465 } else if (opt == 'b') { 6466 if (seen_f) { 6467 _rtld_error("Both -b and -f specified"); 6468 rtld_die(); 6469 } 6470 if (j != arglen - 1) { 6471 _rtld_error("Invalid options: %s", arg); 6472 rtld_die(); 6473 } 6474 i++; 6475 *argv0 = argv[i]; 6476 seen_b = true; 6477 break; 6478 } else if (opt == 'd') { 6479 *dir_ignore = true; 6480 } else if (opt == 'f') { 6481 if (seen_b) { 6482 _rtld_error("Both -b and -f specified"); 6483 rtld_die(); 6484 } 6485 6486 /* 6487 * -f XX can be used to specify a 6488 * descriptor for the binary named at 6489 * the command line (i.e., the later 6490 * argument will specify the process 6491 * name but the descriptor is what 6492 * will actually be executed). 6493 * 6494 * -f must be the last option in the 6495 * group, e.g., -abcf <fd>. 6496 */ 6497 if (j != arglen - 1) { 6498 _rtld_error("Invalid options: %s", arg); 6499 rtld_die(); 6500 } 6501 i++; 6502 fd = parse_integer(argv[i]); 6503 if (fd == -1) { 6504 _rtld_error( 6505 "Invalid file descriptor: '%s'", 6506 argv[i]); 6507 rtld_die(); 6508 } 6509 *fdp = fd; 6510 seen_f = true; 6511 break; 6512 } else if (opt == 'o') { 6513 struct ld_env_var_desc *l; 6514 char *n, *v; 6515 u_int ll; 6516 6517 if (j != arglen - 1) { 6518 _rtld_error("Invalid options: %s", arg); 6519 rtld_die(); 6520 } 6521 i++; 6522 n = argv[i]; 6523 v = strchr(n, '='); 6524 if (v == NULL) { 6525 _rtld_error("No '=' in -o parameter"); 6526 rtld_die(); 6527 } 6528 for (ll = 0; ll < nitems(ld_env_vars); ll++) { 6529 l = &ld_env_vars[ll]; 6530 if (v - n == (ptrdiff_t)strlen(l->n) && 6531 strncmp(n, l->n, v - n) == 0) { 6532 l->val = v + 1; 6533 break; 6534 } 6535 } 6536 if (ll == nitems(ld_env_vars)) { 6537 _rtld_error("Unknown LD_ option %s", n); 6538 rtld_die(); 6539 } 6540 } else if (opt == 'p') { 6541 *use_pathp = true; 6542 } else if (opt == 'u') { 6543 u_int ll; 6544 6545 for (ll = 0; ll < nitems(ld_env_vars); ll++) 6546 ld_env_vars[ll].val = NULL; 6547 } else if (opt == 'v') { 6548 machine[0] = '\0'; 6549 mib[0] = CTL_HW; 6550 mib[1] = HW_MACHINE; 6551 sz = sizeof(machine); 6552 sysctl(mib, nitems(mib), machine, &sz, NULL, 0); 6553 ld_elf_hints_path = ld_get_env_var( 6554 LD_ELF_HINTS_PATH); 6555 set_ld_elf_hints_path(); 6556 rtld_printf( 6557 "FreeBSD ld-elf.so.1 %s\n" 6558 "FreeBSD_version %d\n" 6559 "Default lib path %s\n" 6560 "Hints lib path %s\n" 6561 "Env prefix %s\n" 6562 "Default hint file %s\n" 6563 "Hint file %s\n" 6564 "libmap file %s\n" 6565 "Optional static TLS size %zd bytes\n", 6566 machine, __FreeBSD_version, 6567 ld_standard_library_path, gethints(false), 6568 ld_env_prefix, ld_elf_hints_default, 6569 ld_elf_hints_path, ld_path_libmap_conf, 6570 ld_static_tls_extra); 6571 _exit(0); 6572 } else { 6573 _rtld_error("Invalid argument: '%s'", arg); 6574 print_usage(argv[0]); 6575 rtld_die(); 6576 } 6577 } 6578 } 6579 6580 if (!seen_b) 6581 *argv0 = argv[i]; 6582 return (i); 6583 } 6584 6585 /* 6586 * Parse a file descriptor number without pulling in more of libc (e.g. atoi). 6587 */ 6588 static int 6589 parse_integer(const char *str) 6590 { 6591 int radix; 6592 const char *orig; 6593 int n, val; 6594 char c; 6595 6596 if (str[0] == '0') { 6597 if (str[1] == 'x') { 6598 str += 2; 6599 radix = 16; 6600 } else if (str[1] == 'b') { 6601 str += 2; 6602 radix = 2; 6603 } else { 6604 str += 1; 6605 radix = 8; 6606 } 6607 } else { 6608 radix = 10; 6609 } 6610 orig = str; 6611 n = 0; 6612 for (c = *str; c != '\0'; c = *++str) { 6613 if (c >= '0' && c <= '9') 6614 val = c - '0'; 6615 else if (c >= 'a' && c <= 'f') 6616 val = c - 'a' + 10; 6617 else if (c >= 'A' && c <= 'F') 6618 val = c - 'A' + 10; 6619 else 6620 return (-1); 6621 if (val >= radix) 6622 return (-1); 6623 6624 if (n > INT_MAX / radix) 6625 return (-1); 6626 n *= radix; 6627 if (n > INT_MAX - val) 6628 return (-1); 6629 n += val; 6630 } 6631 6632 /* 6633 * Make sure we actually parsed something. 6634 * Allow for lone '0'. 6635 */ 6636 if (str == orig && radix != 8) 6637 return (-1); 6638 return (n); 6639 } 6640 6641 static void 6642 print_usage(const char *argv0) 6643 { 6644 rtld_printf( 6645 "Usage: %s [-h] [-b <exe>] [-d] [-f <FD>] [-p] [--] <binary> [<args>]\n" 6646 "\n" 6647 "Options:\n" 6648 " -h Display this help message\n" 6649 " -b <exe> Execute <exe> instead of <binary>, arg0 is <binary>\n" 6650 " -d Ignore lack of exec permissions for the binary\n" 6651 " -f <FD> Execute <FD> instead of searching for <binary>\n" 6652 " -o <OPT>=<VAL> Set LD_<OPT> to <VAL>, without polluting env\n" 6653 " -p Search in PATH for named binary\n" 6654 " -u Ignore LD_ environment variables\n" 6655 " -v Display identification information\n" 6656 " -- End of RTLD options\n" 6657 " <binary> Name of process to execute\n" 6658 " <args> Arguments to the executed process\n", 6659 argv0); 6660 } 6661 6662 #define AUXFMT(at, xfmt) [at] = { .name = #at, .fmt = xfmt } 6663 static const struct auxfmt { 6664 const char *name; 6665 const char *fmt; 6666 } auxfmts[] = { 6667 AUXFMT(AT_NULL, NULL), 6668 AUXFMT(AT_IGNORE, NULL), 6669 AUXFMT(AT_EXECFD, "%ld"), 6670 AUXFMT(AT_PHDR, "%p"), 6671 AUXFMT(AT_PHENT, "%lu"), 6672 AUXFMT(AT_PHNUM, "%lu"), 6673 AUXFMT(AT_PAGESZ, "%lu"), 6674 AUXFMT(AT_BASE, "%#lx"), 6675 AUXFMT(AT_FLAGS, "%#lx"), 6676 AUXFMT(AT_ENTRY, "%p"), 6677 AUXFMT(AT_NOTELF, NULL), 6678 AUXFMT(AT_UID, "%ld"), 6679 AUXFMT(AT_EUID, "%ld"), 6680 AUXFMT(AT_GID, "%ld"), 6681 AUXFMT(AT_EGID, "%ld"), 6682 AUXFMT(AT_EXECPATH, "%s"), 6683 AUXFMT(AT_CANARY, "%p"), 6684 AUXFMT(AT_CANARYLEN, "%lu"), 6685 AUXFMT(AT_OSRELDATE, "%lu"), 6686 AUXFMT(AT_NCPUS, "%lu"), 6687 AUXFMT(AT_PAGESIZES, "%p"), 6688 AUXFMT(AT_PAGESIZESLEN, "%lu"), 6689 AUXFMT(AT_TIMEKEEP, "%p"), 6690 AUXFMT(AT_STACKPROT, "%#lx"), 6691 AUXFMT(AT_EHDRFLAGS, "%#lx"), 6692 AUXFMT(AT_HWCAP, "%#lx"), 6693 AUXFMT(AT_HWCAP2, "%#lx"), 6694 AUXFMT(AT_BSDFLAGS, "%#lx"), 6695 AUXFMT(AT_ARGC, "%lu"), 6696 AUXFMT(AT_ARGV, "%p"), 6697 AUXFMT(AT_ENVC, "%p"), 6698 AUXFMT(AT_ENVV, "%p"), 6699 AUXFMT(AT_PS_STRINGS, "%p"), 6700 AUXFMT(AT_FXRNG, "%p"), 6701 AUXFMT(AT_KPRELOAD, "%p"), 6702 AUXFMT(AT_USRSTACKBASE, "%#lx"), 6703 AUXFMT(AT_USRSTACKLIM, "%#lx"), 6704 /* AT_CHERI_STATS */ 6705 AUXFMT(AT_HWCAP3, "%#lx"), 6706 AUXFMT(AT_HWCAP4, "%#lx"), 6707 6708 }; 6709 6710 static bool 6711 is_ptr_fmt(const char *fmt) 6712 { 6713 char last; 6714 6715 last = fmt[strlen(fmt) - 1]; 6716 return (last == 'p' || last == 's'); 6717 } 6718 6719 static void 6720 dump_auxv(Elf_Auxinfo **aux_info) 6721 { 6722 Elf_Auxinfo *auxp; 6723 const struct auxfmt *fmt; 6724 int i; 6725 6726 for (i = 0; i < AT_COUNT; i++) { 6727 auxp = aux_info[i]; 6728 if (auxp == NULL) 6729 continue; 6730 fmt = &auxfmts[i]; 6731 if (fmt->fmt == NULL) 6732 continue; 6733 rtld_fdprintf(STDOUT_FILENO, "%s:\t", fmt->name); 6734 if (is_ptr_fmt(fmt->fmt)) { 6735 rtld_fdprintfx(STDOUT_FILENO, fmt->fmt, 6736 auxp->a_un.a_ptr); 6737 } else { 6738 rtld_fdprintfx(STDOUT_FILENO, fmt->fmt, 6739 auxp->a_un.a_val); 6740 } 6741 rtld_fdprintf(STDOUT_FILENO, "\n"); 6742 } 6743 } 6744 6745 const char * 6746 rtld_get_var(const char *name) 6747 { 6748 const struct ld_env_var_desc *lvd; 6749 u_int i; 6750 6751 for (i = 0; i < nitems(ld_env_vars); i++) { 6752 lvd = &ld_env_vars[i]; 6753 if (strcmp(lvd->n, name) == 0) 6754 return (lvd->val); 6755 } 6756 return (NULL); 6757 } 6758 6759 static void 6760 rtld_recalc_dangerous_ld_env(void) 6761 { 6762 /* 6763 * Never reset dangerous_ld_env back to false if rtld was ever 6764 * contaminated with it set to true. 6765 */ 6766 dangerous_ld_env |= libmap_disable || libmap_override != NULL || 6767 ld_library_path != NULL || ld_preload != NULL || 6768 ld_elf_hints_path != NULL || ld_loadfltr || !ld_dynamic_weak || 6769 ld_get_env_var(LD_STATIC_TLS_EXTRA) != NULL; 6770 } 6771 6772 static void 6773 rtld_recalc_debug(const char *ld_debug) 6774 { 6775 if (ld_debug != NULL && *ld_debug != '\0') 6776 debug = 1; 6777 } 6778 6779 static void 6780 rtld_set_var_debug(struct ld_env_var_desc *lvd) 6781 { 6782 rtld_recalc_debug(lvd->val); 6783 } 6784 6785 static void 6786 rtld_set_var_library_path(struct ld_env_var_desc *lvd) 6787 { 6788 ld_library_path = lvd->val; 6789 } 6790 6791 static void 6792 rtld_set_var_library_path_fds(struct ld_env_var_desc *lvd) 6793 { 6794 ld_library_dirs = lvd->val; 6795 } 6796 6797 static void 6798 rtld_recalc_path_rpath(const char *library_path_rpath) 6799 { 6800 if (library_path_rpath != NULL) { 6801 if (library_path_rpath[0] == 'y' || 6802 library_path_rpath[0] == 'Y' || 6803 library_path_rpath[0] == '1') 6804 ld_library_path_rpath = true; 6805 else 6806 ld_library_path_rpath = false; 6807 } else { 6808 ld_library_path_rpath = false; 6809 } 6810 } 6811 6812 static void 6813 rtld_set_var_library_path_rpath(struct ld_env_var_desc *lvd) 6814 { 6815 rtld_recalc_path_rpath(lvd->val); 6816 } 6817 6818 static void 6819 rtld_recalc_bind_not(const char *bind_not_val) 6820 { 6821 if (ld_bind_now == NULL) 6822 ld_bind_not = bind_not_val != NULL; 6823 } 6824 6825 static void 6826 rtld_set_var_bind_now(struct ld_env_var_desc *lvd) 6827 { 6828 ld_bind_now = lvd->val; 6829 rtld_recalc_bind_not(ld_get_env_var(LD_BIND_NOT)); 6830 } 6831 6832 static void 6833 rtld_set_var_bind_not(struct ld_env_var_desc *lvd) 6834 { 6835 rtld_recalc_bind_not(lvd->val); 6836 } 6837 6838 static void 6839 rtld_set_var_dynamic_weak(struct ld_env_var_desc *lvd) 6840 { 6841 ld_dynamic_weak = lvd->val == NULL; 6842 } 6843 6844 static void 6845 rtld_set_var_loadfltr(struct ld_env_var_desc *lvd) 6846 { 6847 ld_loadfltr = lvd->val != NULL; 6848 } 6849 6850 static void 6851 rtld_set_var_libmap_disable(struct ld_env_var_desc *lvd) 6852 { 6853 libmap_disable = lvd->val != NULL; 6854 } 6855 6856 int 6857 rtld_set_var(const char *name, const char *val) 6858 { 6859 RtldLockState lockstate; 6860 struct ld_env_var_desc *lvd; 6861 u_int i; 6862 int error; 6863 6864 error = ENOENT; 6865 wlock_acquire(rtld_bind_lock, &lockstate); 6866 for (i = 0; i < nitems(ld_env_vars); i++) { 6867 lvd = &ld_env_vars[i]; 6868 if (strcmp(lvd->n, name) != 0) 6869 continue; 6870 if (!lvd->can_update || (lvd->unsecure && !trust)) { 6871 error = EPERM; 6872 break; 6873 } 6874 if (lvd->owned) 6875 free(__DECONST(char *, lvd->val)); 6876 if (val != NULL) 6877 lvd->val = xstrdup(val); 6878 else 6879 lvd->val = NULL; 6880 lvd->owned = true; 6881 if (lvd->on_update != NULL) 6882 lvd->on_update(lvd); 6883 error = 0; 6884 break; 6885 } 6886 if (error == 0) 6887 rtld_recalc_dangerous_ld_env(); 6888 lock_release(rtld_bind_lock, &lockstate); 6889 return (error); 6890 } 6891 6892 /* 6893 * Overrides for libc_pic-provided functions. 6894 */ 6895 6896 int 6897 __getosreldate(void) 6898 { 6899 size_t len; 6900 int oid[2]; 6901 int error, osrel; 6902 6903 if (osreldate != 0) 6904 return (osreldate); 6905 6906 oid[0] = CTL_KERN; 6907 oid[1] = KERN_OSRELDATE; 6908 osrel = 0; 6909 len = sizeof(osrel); 6910 error = sysctl(oid, 2, &osrel, &len, NULL, 0); 6911 if (error == 0 && osrel > 0 && len == sizeof(osrel)) 6912 osreldate = osrel; 6913 return (osreldate); 6914 } 6915 const char * 6916 rtld_strerror(int errnum) 6917 { 6918 if (errnum < 0 || errnum >= sys_nerr) 6919 return ("Unknown error"); 6920 return (sys_errlist[errnum]); 6921 } 6922 6923 char * 6924 getenv(const char *name) 6925 { 6926 return (__DECONST(char *, rtld_get_env_val(environ, name, 6927 strlen(name)))); 6928 } 6929 6930 extern int _rtld_version__FreeBSD_version __exported; 6931 int _rtld_version__FreeBSD_version = __FreeBSD_version; 6932 6933 extern char _rtld_version_laddr_offset __exported; 6934 char _rtld_version_laddr_offset; 6935 6936 extern char _rtld_version_dlpi_tls_data __exported; 6937 char _rtld_version_dlpi_tls_data; 6938