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