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