rtld.c revision 259292
1/*- 2 * Copyright 1996, 1997, 1998, 1999, 2000 John D. Polstra. 3 * Copyright 2003 Alexander Kabaev <kan@FreeBSD.ORG>. 4 * Copyright 2009-2012 Konstantin Belousov <kib@FreeBSD.ORG>. 5 * Copyright 2012 John Marino <draco@marino.st>. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 * 28 * $FreeBSD: stable/10/libexec/rtld-elf/rtld.c 259292 2013-12-13 06:06:08Z kib $ 29 */ 30 31/* 32 * Dynamic linker for ELF. 33 * 34 * John Polstra <jdp@polstra.com>. 35 */ 36 37#ifndef __GNUC__ 38#error "GCC is needed to compile this file" 39#endif 40 41#include <sys/param.h> 42#include <sys/mount.h> 43#include <sys/mman.h> 44#include <sys/stat.h> 45#include <sys/sysctl.h> 46#include <sys/uio.h> 47#include <sys/utsname.h> 48#include <sys/ktrace.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 "rtld.h" 62#include "libmap.h" 63#include "rtld_tls.h" 64#include "rtld_printf.h" 65#include "notes.h" 66 67#ifndef COMPAT_32BIT 68#define PATH_RTLD "/libexec/ld-elf.so.1" 69#else 70#define PATH_RTLD "/libexec/ld-elf32.so.1" 71#endif 72 73/* Types. */ 74typedef void (*func_ptr_type)(); 75typedef void * (*path_enum_proc) (const char *path, size_t len, void *arg); 76 77/* 78 * Function declarations. 79 */ 80static const char *basename(const char *); 81static void die(void) __dead2; 82static void digest_dynamic1(Obj_Entry *, int, const Elf_Dyn **, 83 const Elf_Dyn **, const Elf_Dyn **); 84static void digest_dynamic2(Obj_Entry *, const Elf_Dyn *, const Elf_Dyn *, 85 const Elf_Dyn *); 86static void digest_dynamic(Obj_Entry *, int); 87static Obj_Entry *digest_phdr(const Elf_Phdr *, int, caddr_t, const char *); 88static Obj_Entry *dlcheck(void *); 89static Obj_Entry *dlopen_object(const char *name, int fd, Obj_Entry *refobj, 90 int lo_flags, int mode, RtldLockState *lockstate); 91static Obj_Entry *do_load_object(int, const char *, char *, struct stat *, int); 92static int do_search_info(const Obj_Entry *obj, int, struct dl_serinfo *); 93static bool donelist_check(DoneList *, const Obj_Entry *); 94static void errmsg_restore(char *); 95static char *errmsg_save(void); 96static void *fill_search_info(const char *, size_t, void *); 97static char *find_library(const char *, const Obj_Entry *); 98static const char *gethints(bool); 99static void init_dag(Obj_Entry *); 100static void init_rtld(caddr_t, Elf_Auxinfo **); 101static void initlist_add_neededs(Needed_Entry *, Objlist *); 102static void initlist_add_objects(Obj_Entry *, Obj_Entry **, Objlist *); 103static void linkmap_add(Obj_Entry *); 104static void linkmap_delete(Obj_Entry *); 105static void load_filtees(Obj_Entry *, int flags, RtldLockState *); 106static void unload_filtees(Obj_Entry *); 107static int load_needed_objects(Obj_Entry *, int); 108static int load_preload_objects(void); 109static Obj_Entry *load_object(const char *, int fd, const Obj_Entry *, int); 110static void map_stacks_exec(RtldLockState *); 111static Obj_Entry *obj_from_addr(const void *); 112static void objlist_call_fini(Objlist *, Obj_Entry *, RtldLockState *); 113static void objlist_call_init(Objlist *, RtldLockState *); 114static void objlist_clear(Objlist *); 115static Objlist_Entry *objlist_find(Objlist *, const Obj_Entry *); 116static void objlist_init(Objlist *); 117static void objlist_push_head(Objlist *, Obj_Entry *); 118static void objlist_push_tail(Objlist *, Obj_Entry *); 119static void objlist_put_after(Objlist *, Obj_Entry *, Obj_Entry *); 120static void objlist_remove(Objlist *, Obj_Entry *); 121static void *path_enumerate(const char *, path_enum_proc, void *); 122static int relocate_object_dag(Obj_Entry *root, bool bind_now, 123 Obj_Entry *rtldobj, int flags, RtldLockState *lockstate); 124static int relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, 125 int flags, RtldLockState *lockstate); 126static int relocate_objects(Obj_Entry *, bool, Obj_Entry *, int, 127 RtldLockState *); 128static int resolve_objects_ifunc(Obj_Entry *first, bool bind_now, 129 int flags, RtldLockState *lockstate); 130static int rtld_dirname(const char *, char *); 131static int rtld_dirname_abs(const char *, char *); 132static void *rtld_dlopen(const char *name, int fd, int mode); 133static void rtld_exit(void); 134static char *search_library_path(const char *, const char *); 135static const void **get_program_var_addr(const char *, RtldLockState *); 136static void set_program_var(const char *, const void *); 137static int symlook_default(SymLook *, const Obj_Entry *refobj); 138static int symlook_global(SymLook *, DoneList *); 139static void symlook_init_from_req(SymLook *, const SymLook *); 140static int symlook_list(SymLook *, const Objlist *, DoneList *); 141static int symlook_needed(SymLook *, const Needed_Entry *, DoneList *); 142static int symlook_obj1_sysv(SymLook *, const Obj_Entry *); 143static int symlook_obj1_gnu(SymLook *, const Obj_Entry *); 144static void trace_loaded_objects(Obj_Entry *); 145static void unlink_object(Obj_Entry *); 146static void unload_object(Obj_Entry *); 147static void unref_dag(Obj_Entry *); 148static void ref_dag(Obj_Entry *); 149static char *origin_subst_one(char *, const char *, const char *, bool); 150static char *origin_subst(char *, const char *); 151static void preinit_main(void); 152static int rtld_verify_versions(const Objlist *); 153static int rtld_verify_object_versions(Obj_Entry *); 154static void object_add_name(Obj_Entry *, const char *); 155static int object_match_name(const Obj_Entry *, const char *); 156static void ld_utrace_log(int, void *, void *, size_t, int, const char *); 157static void rtld_fill_dl_phdr_info(const Obj_Entry *obj, 158 struct dl_phdr_info *phdr_info); 159static uint32_t gnu_hash(const char *); 160static bool matched_symbol(SymLook *, const Obj_Entry *, Sym_Match_Result *, 161 const unsigned long); 162 163void r_debug_state(struct r_debug *, struct link_map *) __noinline; 164 165/* 166 * Data declarations. 167 */ 168static char *error_message; /* Message for dlerror(), or NULL */ 169struct r_debug r_debug; /* for GDB; */ 170static bool libmap_disable; /* Disable libmap */ 171static bool ld_loadfltr; /* Immediate filters processing */ 172static char *libmap_override; /* Maps to use in addition to libmap.conf */ 173static bool trust; /* False for setuid and setgid programs */ 174static bool dangerous_ld_env; /* True if environment variables have been 175 used to affect the libraries loaded */ 176static char *ld_bind_now; /* Environment variable for immediate binding */ 177static char *ld_debug; /* Environment variable for debugging */ 178static char *ld_library_path; /* Environment variable for search path */ 179static char *ld_preload; /* Environment variable for libraries to 180 load first */ 181static char *ld_elf_hints_path; /* Environment variable for alternative hints path */ 182static char *ld_tracing; /* Called from ldd to print libs */ 183static char *ld_utrace; /* Use utrace() to log events. */ 184static Obj_Entry *obj_list; /* Head of linked list of shared objects */ 185static Obj_Entry **obj_tail; /* Link field of last object in list */ 186static Obj_Entry *obj_main; /* The main program shared object */ 187static Obj_Entry obj_rtld; /* The dynamic linker shared object */ 188static unsigned int obj_count; /* Number of objects in obj_list */ 189static unsigned int obj_loads; /* Number of objects in obj_list */ 190 191static Objlist list_global = /* Objects dlopened with RTLD_GLOBAL */ 192 STAILQ_HEAD_INITIALIZER(list_global); 193static Objlist list_main = /* Objects loaded at program startup */ 194 STAILQ_HEAD_INITIALIZER(list_main); 195static Objlist list_fini = /* Objects needing fini() calls */ 196 STAILQ_HEAD_INITIALIZER(list_fini); 197 198Elf_Sym sym_zero; /* For resolving undefined weak refs. */ 199 200#define GDB_STATE(s,m) r_debug.r_state = s; r_debug_state(&r_debug,m); 201 202extern Elf_Dyn _DYNAMIC; 203#pragma weak _DYNAMIC 204#ifndef RTLD_IS_DYNAMIC 205#define RTLD_IS_DYNAMIC() (&_DYNAMIC != NULL) 206#endif 207 208int osreldate, pagesize; 209 210long __stack_chk_guard[8] = {0, 0, 0, 0, 0, 0, 0, 0}; 211 212static int stack_prot = PROT_READ | PROT_WRITE | RTLD_DEFAULT_STACK_EXEC; 213static int max_stack_flags; 214 215/* 216 * Global declarations normally provided by crt1. The dynamic linker is 217 * not built with crt1, so we have to provide them ourselves. 218 */ 219char *__progname; 220char **environ; 221 222/* 223 * Used to pass argc, argv to init functions. 224 */ 225int main_argc; 226char **main_argv; 227 228/* 229 * Globals to control TLS allocation. 230 */ 231size_t tls_last_offset; /* Static TLS offset of last module */ 232size_t tls_last_size; /* Static TLS size of last module */ 233size_t tls_static_space; /* Static TLS space allocated */ 234size_t tls_static_max_align; 235int tls_dtv_generation = 1; /* Used to detect when dtv size changes */ 236int tls_max_index = 1; /* Largest module index allocated */ 237 238bool ld_library_path_rpath = false; 239 240/* 241 * Fill in a DoneList with an allocation large enough to hold all of 242 * the currently-loaded objects. Keep this as a macro since it calls 243 * alloca and we want that to occur within the scope of the caller. 244 */ 245#define donelist_init(dlp) \ 246 ((dlp)->objs = alloca(obj_count * sizeof (dlp)->objs[0]), \ 247 assert((dlp)->objs != NULL), \ 248 (dlp)->num_alloc = obj_count, \ 249 (dlp)->num_used = 0) 250 251#define UTRACE_DLOPEN_START 1 252#define UTRACE_DLOPEN_STOP 2 253#define UTRACE_DLCLOSE_START 3 254#define UTRACE_DLCLOSE_STOP 4 255#define UTRACE_LOAD_OBJECT 5 256#define UTRACE_UNLOAD_OBJECT 6 257#define UTRACE_ADD_RUNDEP 7 258#define UTRACE_PRELOAD_FINISHED 8 259#define UTRACE_INIT_CALL 9 260#define UTRACE_FINI_CALL 10 261 262struct utrace_rtld { 263 char sig[4]; /* 'RTLD' */ 264 int event; 265 void *handle; 266 void *mapbase; /* Used for 'parent' and 'init/fini' */ 267 size_t mapsize; 268 int refcnt; /* Used for 'mode' */ 269 char name[MAXPATHLEN]; 270}; 271 272#define LD_UTRACE(e, h, mb, ms, r, n) do { \ 273 if (ld_utrace != NULL) \ 274 ld_utrace_log(e, h, mb, ms, r, n); \ 275} while (0) 276 277static void 278ld_utrace_log(int event, void *handle, void *mapbase, size_t mapsize, 279 int refcnt, const char *name) 280{ 281 struct utrace_rtld ut; 282 283 ut.sig[0] = 'R'; 284 ut.sig[1] = 'T'; 285 ut.sig[2] = 'L'; 286 ut.sig[3] = 'D'; 287 ut.event = event; 288 ut.handle = handle; 289 ut.mapbase = mapbase; 290 ut.mapsize = mapsize; 291 ut.refcnt = refcnt; 292 bzero(ut.name, sizeof(ut.name)); 293 if (name) 294 strlcpy(ut.name, name, sizeof(ut.name)); 295 utrace(&ut, sizeof(ut)); 296} 297 298/* 299 * Main entry point for dynamic linking. The first argument is the 300 * stack pointer. The stack is expected to be laid out as described 301 * in the SVR4 ABI specification, Intel 386 Processor Supplement. 302 * Specifically, the stack pointer points to a word containing 303 * ARGC. Following that in the stack is a null-terminated sequence 304 * of pointers to argument strings. Then comes a null-terminated 305 * sequence of pointers to environment strings. Finally, there is a 306 * sequence of "auxiliary vector" entries. 307 * 308 * The second argument points to a place to store the dynamic linker's 309 * exit procedure pointer and the third to a place to store the main 310 * program's object. 311 * 312 * The return value is the main program's entry point. 313 */ 314func_ptr_type 315_rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp) 316{ 317 Elf_Auxinfo *aux_info[AT_COUNT]; 318 int i; 319 int argc; 320 char **argv; 321 char **env; 322 Elf_Auxinfo *aux; 323 Elf_Auxinfo *auxp; 324 const char *argv0; 325 Objlist_Entry *entry; 326 Obj_Entry *obj; 327 Obj_Entry **preload_tail; 328 Obj_Entry *last_interposer; 329 Objlist initlist; 330 RtldLockState lockstate; 331 char *library_path_rpath; 332 int mib[2]; 333 size_t len; 334 335 /* 336 * On entry, the dynamic linker itself has not been relocated yet. 337 * Be very careful not to reference any global data until after 338 * init_rtld has returned. It is OK to reference file-scope statics 339 * and string constants, and to call static and global functions. 340 */ 341 342 /* Find the auxiliary vector on the stack. */ 343 argc = *sp++; 344 argv = (char **) sp; 345 sp += argc + 1; /* Skip over arguments and NULL terminator */ 346 env = (char **) sp; 347 while (*sp++ != 0) /* Skip over environment, and NULL terminator */ 348 ; 349 aux = (Elf_Auxinfo *) sp; 350 351 /* Digest the auxiliary vector. */ 352 for (i = 0; i < AT_COUNT; i++) 353 aux_info[i] = NULL; 354 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) { 355 if (auxp->a_type < AT_COUNT) 356 aux_info[auxp->a_type] = auxp; 357 } 358 359 /* Initialize and relocate ourselves. */ 360 assert(aux_info[AT_BASE] != NULL); 361 init_rtld((caddr_t) aux_info[AT_BASE]->a_un.a_ptr, aux_info); 362 363 __progname = obj_rtld.path; 364 argv0 = argv[0] != NULL ? argv[0] : "(null)"; 365 environ = env; 366 main_argc = argc; 367 main_argv = argv; 368 369 if (aux_info[AT_CANARY] != NULL && 370 aux_info[AT_CANARY]->a_un.a_ptr != NULL) { 371 i = aux_info[AT_CANARYLEN]->a_un.a_val; 372 if (i > sizeof(__stack_chk_guard)) 373 i = sizeof(__stack_chk_guard); 374 memcpy(__stack_chk_guard, aux_info[AT_CANARY]->a_un.a_ptr, i); 375 } else { 376 mib[0] = CTL_KERN; 377 mib[1] = KERN_ARND; 378 379 len = sizeof(__stack_chk_guard); 380 if (sysctl(mib, 2, __stack_chk_guard, &len, NULL, 0) == -1 || 381 len != sizeof(__stack_chk_guard)) { 382 /* If sysctl was unsuccessful, use the "terminator canary". */ 383 ((unsigned char *)(void *)__stack_chk_guard)[0] = 0; 384 ((unsigned char *)(void *)__stack_chk_guard)[1] = 0; 385 ((unsigned char *)(void *)__stack_chk_guard)[2] = '\n'; 386 ((unsigned char *)(void *)__stack_chk_guard)[3] = 255; 387 } 388 } 389 390 trust = !issetugid(); 391 392 ld_bind_now = getenv(LD_ "BIND_NOW"); 393 /* 394 * If the process is tainted, then we un-set the dangerous environment 395 * variables. The process will be marked as tainted until setuid(2) 396 * is called. If any child process calls setuid(2) we do not want any 397 * future processes to honor the potentially un-safe variables. 398 */ 399 if (!trust) { 400 if (unsetenv(LD_ "PRELOAD") || unsetenv(LD_ "LIBMAP") || 401 unsetenv(LD_ "LIBRARY_PATH") || unsetenv(LD_ "LIBMAP_DISABLE") || 402 unsetenv(LD_ "DEBUG") || unsetenv(LD_ "ELF_HINTS_PATH") || 403 unsetenv(LD_ "LOADFLTR") || unsetenv(LD_ "LIBRARY_PATH_RPATH")) { 404 _rtld_error("environment corrupt; aborting"); 405 die(); 406 } 407 } 408 ld_debug = getenv(LD_ "DEBUG"); 409 libmap_disable = getenv(LD_ "LIBMAP_DISABLE") != NULL; 410 libmap_override = getenv(LD_ "LIBMAP"); 411 ld_library_path = getenv(LD_ "LIBRARY_PATH"); 412 ld_preload = getenv(LD_ "PRELOAD"); 413 ld_elf_hints_path = getenv(LD_ "ELF_HINTS_PATH"); 414 ld_loadfltr = getenv(LD_ "LOADFLTR") != NULL; 415 library_path_rpath = getenv(LD_ "LIBRARY_PATH_RPATH"); 416 if (library_path_rpath != NULL) { 417 if (library_path_rpath[0] == 'y' || 418 library_path_rpath[0] == 'Y' || 419 library_path_rpath[0] == '1') 420 ld_library_path_rpath = true; 421 else 422 ld_library_path_rpath = false; 423 } 424 dangerous_ld_env = libmap_disable || (libmap_override != NULL) || 425 (ld_library_path != NULL) || (ld_preload != NULL) || 426 (ld_elf_hints_path != NULL) || ld_loadfltr; 427 ld_tracing = getenv(LD_ "TRACE_LOADED_OBJECTS"); 428 ld_utrace = getenv(LD_ "UTRACE"); 429 430 if ((ld_elf_hints_path == NULL) || strlen(ld_elf_hints_path) == 0) 431 ld_elf_hints_path = _PATH_ELF_HINTS; 432 433 if (ld_debug != NULL && *ld_debug != '\0') 434 debug = 1; 435 dbg("%s is initialized, base address = %p", __progname, 436 (caddr_t) aux_info[AT_BASE]->a_un.a_ptr); 437 dbg("RTLD dynamic = %p", obj_rtld.dynamic); 438 dbg("RTLD pltgot = %p", obj_rtld.pltgot); 439 440 dbg("initializing thread locks"); 441 lockdflt_init(); 442 443 /* 444 * Load the main program, or process its program header if it is 445 * already loaded. 446 */ 447 if (aux_info[AT_EXECFD] != NULL) { /* Load the main program. */ 448 int fd = aux_info[AT_EXECFD]->a_un.a_val; 449 dbg("loading main program"); 450 obj_main = map_object(fd, argv0, NULL); 451 close(fd); 452 if (obj_main == NULL) 453 die(); 454 max_stack_flags = obj->stack_flags; 455 } else { /* Main program already loaded. */ 456 const Elf_Phdr *phdr; 457 int phnum; 458 caddr_t entry; 459 460 dbg("processing main program's program header"); 461 assert(aux_info[AT_PHDR] != NULL); 462 phdr = (const Elf_Phdr *) aux_info[AT_PHDR]->a_un.a_ptr; 463 assert(aux_info[AT_PHNUM] != NULL); 464 phnum = aux_info[AT_PHNUM]->a_un.a_val; 465 assert(aux_info[AT_PHENT] != NULL); 466 assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr)); 467 assert(aux_info[AT_ENTRY] != NULL); 468 entry = (caddr_t) aux_info[AT_ENTRY]->a_un.a_ptr; 469 if ((obj_main = digest_phdr(phdr, phnum, entry, argv0)) == NULL) 470 die(); 471 } 472 473 if (aux_info[AT_EXECPATH] != 0) { 474 char *kexecpath; 475 char buf[MAXPATHLEN]; 476 477 kexecpath = aux_info[AT_EXECPATH]->a_un.a_ptr; 478 dbg("AT_EXECPATH %p %s", kexecpath, kexecpath); 479 if (kexecpath[0] == '/') 480 obj_main->path = kexecpath; 481 else if (getcwd(buf, sizeof(buf)) == NULL || 482 strlcat(buf, "/", sizeof(buf)) >= sizeof(buf) || 483 strlcat(buf, kexecpath, sizeof(buf)) >= sizeof(buf)) 484 obj_main->path = xstrdup(argv0); 485 else 486 obj_main->path = xstrdup(buf); 487 } else { 488 dbg("No AT_EXECPATH"); 489 obj_main->path = xstrdup(argv0); 490 } 491 dbg("obj_main path %s", obj_main->path); 492 obj_main->mainprog = true; 493 494 if (aux_info[AT_STACKPROT] != NULL && 495 aux_info[AT_STACKPROT]->a_un.a_val != 0) 496 stack_prot = aux_info[AT_STACKPROT]->a_un.a_val; 497 498 /* 499 * Get the actual dynamic linker pathname from the executable if 500 * possible. (It should always be possible.) That ensures that 501 * gdb will find the right dynamic linker even if a non-standard 502 * one is being used. 503 */ 504 if (obj_main->interp != NULL && 505 strcmp(obj_main->interp, obj_rtld.path) != 0) { 506 free(obj_rtld.path); 507 obj_rtld.path = xstrdup(obj_main->interp); 508 __progname = obj_rtld.path; 509 } 510 511 digest_dynamic(obj_main, 0); 512 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", 513 obj_main->path, obj_main->valid_hash_sysv, obj_main->valid_hash_gnu, 514 obj_main->dynsymcount); 515 516 linkmap_add(obj_main); 517 linkmap_add(&obj_rtld); 518 519 /* Link the main program into the list of objects. */ 520 *obj_tail = obj_main; 521 obj_tail = &obj_main->next; 522 obj_count++; 523 obj_loads++; 524 525 /* Initialize a fake symbol for resolving undefined weak references. */ 526 sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE); 527 sym_zero.st_shndx = SHN_UNDEF; 528 sym_zero.st_value = -(uintptr_t)obj_main->relocbase; 529 530 if (!libmap_disable) 531 libmap_disable = (bool)lm_init(libmap_override); 532 533 dbg("loading LD_PRELOAD libraries"); 534 if (load_preload_objects() == -1) 535 die(); 536 preload_tail = obj_tail; 537 538 dbg("loading needed objects"); 539 if (load_needed_objects(obj_main, 0) == -1) 540 die(); 541 542 /* Make a list of all objects loaded at startup. */ 543 last_interposer = obj_main; 544 for (obj = obj_list; obj != NULL; obj = obj->next) { 545 if (obj->z_interpose && obj != obj_main) { 546 objlist_put_after(&list_main, last_interposer, obj); 547 last_interposer = obj; 548 } else { 549 objlist_push_tail(&list_main, obj); 550 } 551 obj->refcount++; 552 } 553 554 dbg("checking for required versions"); 555 if (rtld_verify_versions(&list_main) == -1 && !ld_tracing) 556 die(); 557 558 if (ld_tracing) { /* We're done */ 559 trace_loaded_objects(obj_main); 560 exit(0); 561 } 562 563 if (getenv(LD_ "DUMP_REL_PRE") != NULL) { 564 dump_relocations(obj_main); 565 exit (0); 566 } 567 568 /* 569 * Processing tls relocations requires having the tls offsets 570 * initialized. Prepare offsets before starting initial 571 * relocation processing. 572 */ 573 dbg("initializing initial thread local storage offsets"); 574 STAILQ_FOREACH(entry, &list_main, link) { 575 /* 576 * Allocate all the initial objects out of the static TLS 577 * block even if they didn't ask for it. 578 */ 579 allocate_tls_offset(entry->obj); 580 } 581 582 if (relocate_objects(obj_main, 583 ld_bind_now != NULL && *ld_bind_now != '\0', 584 &obj_rtld, SYMLOOK_EARLY, NULL) == -1) 585 die(); 586 587 dbg("doing copy relocations"); 588 if (do_copy_relocations(obj_main) == -1) 589 die(); 590 591 if (getenv(LD_ "DUMP_REL_POST") != NULL) { 592 dump_relocations(obj_main); 593 exit (0); 594 } 595 596 /* 597 * Setup TLS for main thread. This must be done after the 598 * relocations are processed, since tls initialization section 599 * might be the subject for relocations. 600 */ 601 dbg("initializing initial thread local storage"); 602 allocate_initial_tls(obj_list); 603 604 dbg("initializing key program variables"); 605 set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : ""); 606 set_program_var("environ", env); 607 set_program_var("__elf_aux_vector", aux); 608 609 /* Make a list of init functions to call. */ 610 objlist_init(&initlist); 611 initlist_add_objects(obj_list, preload_tail, &initlist); 612 613 r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */ 614 615 map_stacks_exec(NULL); 616 617 dbg("resolving ifuncs"); 618 if (resolve_objects_ifunc(obj_main, 619 ld_bind_now != NULL && *ld_bind_now != '\0', SYMLOOK_EARLY, 620 NULL) == -1) 621 die(); 622 623 if (!obj_main->crt_no_init) { 624 /* 625 * Make sure we don't call the main program's init and fini 626 * functions for binaries linked with old crt1 which calls 627 * _init itself. 628 */ 629 obj_main->init = obj_main->fini = (Elf_Addr)NULL; 630 obj_main->preinit_array = obj_main->init_array = 631 obj_main->fini_array = (Elf_Addr)NULL; 632 } 633 634 wlock_acquire(rtld_bind_lock, &lockstate); 635 if (obj_main->crt_no_init) 636 preinit_main(); 637 objlist_call_init(&initlist, &lockstate); 638 objlist_clear(&initlist); 639 dbg("loading filtees"); 640 for (obj = obj_list->next; obj != NULL; obj = obj->next) { 641 if (ld_loadfltr || obj->z_loadfltr) 642 load_filtees(obj, 0, &lockstate); 643 } 644 lock_release(rtld_bind_lock, &lockstate); 645 646 dbg("transferring control to program entry point = %p", obj_main->entry); 647 648 /* Return the exit procedure and the program entry point. */ 649 *exit_proc = rtld_exit; 650 *objp = obj_main; 651 return (func_ptr_type) obj_main->entry; 652} 653 654void * 655rtld_resolve_ifunc(const Obj_Entry *obj, const Elf_Sym *def) 656{ 657 void *ptr; 658 Elf_Addr target; 659 660 ptr = (void *)make_function_pointer(def, obj); 661 target = ((Elf_Addr (*)(void))ptr)(); 662 return ((void *)target); 663} 664 665Elf_Addr 666_rtld_bind(Obj_Entry *obj, Elf_Size reloff) 667{ 668 const Elf_Rel *rel; 669 const Elf_Sym *def; 670 const Obj_Entry *defobj; 671 Elf_Addr *where; 672 Elf_Addr target; 673 RtldLockState lockstate; 674 675 rlock_acquire(rtld_bind_lock, &lockstate); 676 if (sigsetjmp(lockstate.env, 0) != 0) 677 lock_upgrade(rtld_bind_lock, &lockstate); 678 if (obj->pltrel) 679 rel = (const Elf_Rel *) ((caddr_t) obj->pltrel + reloff); 680 else 681 rel = (const Elf_Rel *) ((caddr_t) obj->pltrela + reloff); 682 683 where = (Elf_Addr *) (obj->relocbase + rel->r_offset); 684 def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, true, NULL, 685 &lockstate); 686 if (def == NULL) 687 die(); 688 if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 689 target = (Elf_Addr)rtld_resolve_ifunc(defobj, def); 690 else 691 target = (Elf_Addr)(defobj->relocbase + def->st_value); 692 693 dbg("\"%s\" in \"%s\" ==> %p in \"%s\"", 694 defobj->strtab + def->st_name, basename(obj->path), 695 (void *)target, basename(defobj->path)); 696 697 /* 698 * Write the new contents for the jmpslot. Note that depending on 699 * architecture, the value which we need to return back to the 700 * lazy binding trampoline may or may not be the target 701 * address. The value returned from reloc_jmpslot() is the value 702 * that the trampoline needs. 703 */ 704 target = reloc_jmpslot(where, target, defobj, obj, rel); 705 lock_release(rtld_bind_lock, &lockstate); 706 return target; 707} 708 709/* 710 * Error reporting function. Use it like printf. If formats the message 711 * into a buffer, and sets things up so that the next call to dlerror() 712 * will return the message. 713 */ 714void 715_rtld_error(const char *fmt, ...) 716{ 717 static char buf[512]; 718 va_list ap; 719 720 va_start(ap, fmt); 721 rtld_vsnprintf(buf, sizeof buf, fmt, ap); 722 error_message = buf; 723 va_end(ap); 724} 725 726/* 727 * Return a dynamically-allocated copy of the current error message, if any. 728 */ 729static char * 730errmsg_save(void) 731{ 732 return error_message == NULL ? NULL : xstrdup(error_message); 733} 734 735/* 736 * Restore the current error message from a copy which was previously saved 737 * by errmsg_save(). The copy is freed. 738 */ 739static void 740errmsg_restore(char *saved_msg) 741{ 742 if (saved_msg == NULL) 743 error_message = NULL; 744 else { 745 _rtld_error("%s", saved_msg); 746 free(saved_msg); 747 } 748} 749 750static const char * 751basename(const char *name) 752{ 753 const char *p = strrchr(name, '/'); 754 return p != NULL ? p + 1 : name; 755} 756 757static struct utsname uts; 758 759static char * 760origin_subst_one(char *real, const char *kw, const char *subst, 761 bool may_free) 762{ 763 char *p, *p1, *res, *resp; 764 int subst_len, kw_len, subst_count, old_len, new_len; 765 766 kw_len = strlen(kw); 767 768 /* 769 * First, count the number of the keyword occurences, to 770 * preallocate the final string. 771 */ 772 for (p = real, subst_count = 0;; p = p1 + kw_len, subst_count++) { 773 p1 = strstr(p, kw); 774 if (p1 == NULL) 775 break; 776 } 777 778 /* 779 * If the keyword is not found, just return. 780 */ 781 if (subst_count == 0) 782 return (may_free ? real : xstrdup(real)); 783 784 /* 785 * There is indeed something to substitute. Calculate the 786 * length of the resulting string, and allocate it. 787 */ 788 subst_len = strlen(subst); 789 old_len = strlen(real); 790 new_len = old_len + (subst_len - kw_len) * subst_count; 791 res = xmalloc(new_len + 1); 792 793 /* 794 * Now, execute the substitution loop. 795 */ 796 for (p = real, resp = res, *resp = '\0';;) { 797 p1 = strstr(p, kw); 798 if (p1 != NULL) { 799 /* Copy the prefix before keyword. */ 800 memcpy(resp, p, p1 - p); 801 resp += p1 - p; 802 /* Keyword replacement. */ 803 memcpy(resp, subst, subst_len); 804 resp += subst_len; 805 *resp = '\0'; 806 p = p1 + kw_len; 807 } else 808 break; 809 } 810 811 /* Copy to the end of string and finish. */ 812 strcat(resp, p); 813 if (may_free) 814 free(real); 815 return (res); 816} 817 818static char * 819origin_subst(char *real, const char *origin_path) 820{ 821 char *res1, *res2, *res3, *res4; 822 823 if (uts.sysname[0] == '\0') { 824 if (uname(&uts) != 0) { 825 _rtld_error("utsname failed: %d", errno); 826 return (NULL); 827 } 828 } 829 res1 = origin_subst_one(real, "$ORIGIN", origin_path, false); 830 res2 = origin_subst_one(res1, "$OSNAME", uts.sysname, true); 831 res3 = origin_subst_one(res2, "$OSREL", uts.release, true); 832 res4 = origin_subst_one(res3, "$PLATFORM", uts.machine, true); 833 return (res4); 834} 835 836static void 837die(void) 838{ 839 const char *msg = dlerror(); 840 841 if (msg == NULL) 842 msg = "Fatal error"; 843 rtld_fdputstr(STDERR_FILENO, msg); 844 rtld_fdputchar(STDERR_FILENO, '\n'); 845 _exit(1); 846} 847 848/* 849 * Process a shared object's DYNAMIC section, and save the important 850 * information in its Obj_Entry structure. 851 */ 852static void 853digest_dynamic1(Obj_Entry *obj, int early, const Elf_Dyn **dyn_rpath, 854 const Elf_Dyn **dyn_soname, const Elf_Dyn **dyn_runpath) 855{ 856 const Elf_Dyn *dynp; 857 Needed_Entry **needed_tail = &obj->needed; 858 Needed_Entry **needed_filtees_tail = &obj->needed_filtees; 859 Needed_Entry **needed_aux_filtees_tail = &obj->needed_aux_filtees; 860 const Elf_Hashelt *hashtab; 861 const Elf32_Word *hashval; 862 Elf32_Word bkt, nmaskwords; 863 int bloom_size32; 864 bool nmw_power2; 865 int plttype = DT_REL; 866 867 *dyn_rpath = NULL; 868 *dyn_soname = NULL; 869 *dyn_runpath = NULL; 870 871 obj->bind_now = false; 872 for (dynp = obj->dynamic; dynp->d_tag != DT_NULL; dynp++) { 873 switch (dynp->d_tag) { 874 875 case DT_REL: 876 obj->rel = (const Elf_Rel *) (obj->relocbase + dynp->d_un.d_ptr); 877 break; 878 879 case DT_RELSZ: 880 obj->relsize = dynp->d_un.d_val; 881 break; 882 883 case DT_RELENT: 884 assert(dynp->d_un.d_val == sizeof(Elf_Rel)); 885 break; 886 887 case DT_JMPREL: 888 obj->pltrel = (const Elf_Rel *) 889 (obj->relocbase + dynp->d_un.d_ptr); 890 break; 891 892 case DT_PLTRELSZ: 893 obj->pltrelsize = dynp->d_un.d_val; 894 break; 895 896 case DT_RELA: 897 obj->rela = (const Elf_Rela *) (obj->relocbase + dynp->d_un.d_ptr); 898 break; 899 900 case DT_RELASZ: 901 obj->relasize = dynp->d_un.d_val; 902 break; 903 904 case DT_RELAENT: 905 assert(dynp->d_un.d_val == sizeof(Elf_Rela)); 906 break; 907 908 case DT_PLTREL: 909 plttype = dynp->d_un.d_val; 910 assert(dynp->d_un.d_val == DT_REL || plttype == DT_RELA); 911 break; 912 913 case DT_SYMTAB: 914 obj->symtab = (const Elf_Sym *) 915 (obj->relocbase + dynp->d_un.d_ptr); 916 break; 917 918 case DT_SYMENT: 919 assert(dynp->d_un.d_val == sizeof(Elf_Sym)); 920 break; 921 922 case DT_STRTAB: 923 obj->strtab = (const char *) (obj->relocbase + dynp->d_un.d_ptr); 924 break; 925 926 case DT_STRSZ: 927 obj->strsize = dynp->d_un.d_val; 928 break; 929 930 case DT_VERNEED: 931 obj->verneed = (const Elf_Verneed *) (obj->relocbase + 932 dynp->d_un.d_val); 933 break; 934 935 case DT_VERNEEDNUM: 936 obj->verneednum = dynp->d_un.d_val; 937 break; 938 939 case DT_VERDEF: 940 obj->verdef = (const Elf_Verdef *) (obj->relocbase + 941 dynp->d_un.d_val); 942 break; 943 944 case DT_VERDEFNUM: 945 obj->verdefnum = dynp->d_un.d_val; 946 break; 947 948 case DT_VERSYM: 949 obj->versyms = (const Elf_Versym *)(obj->relocbase + 950 dynp->d_un.d_val); 951 break; 952 953 case DT_HASH: 954 { 955 hashtab = (const Elf_Hashelt *)(obj->relocbase + 956 dynp->d_un.d_ptr); 957 obj->nbuckets = hashtab[0]; 958 obj->nchains = hashtab[1]; 959 obj->buckets = hashtab + 2; 960 obj->chains = obj->buckets + obj->nbuckets; 961 obj->valid_hash_sysv = obj->nbuckets > 0 && obj->nchains > 0 && 962 obj->buckets != NULL; 963 } 964 break; 965 966 case DT_GNU_HASH: 967 { 968 hashtab = (const Elf_Hashelt *)(obj->relocbase + 969 dynp->d_un.d_ptr); 970 obj->nbuckets_gnu = hashtab[0]; 971 obj->symndx_gnu = hashtab[1]; 972 nmaskwords = hashtab[2]; 973 bloom_size32 = (__ELF_WORD_SIZE / 32) * nmaskwords; 974 /* Number of bitmask words is required to be power of 2 */ 975 nmw_power2 = ((nmaskwords & (nmaskwords - 1)) == 0); 976 obj->maskwords_bm_gnu = nmaskwords - 1; 977 obj->shift2_gnu = hashtab[3]; 978 obj->bloom_gnu = (Elf_Addr *) (hashtab + 4); 979 obj->buckets_gnu = hashtab + 4 + bloom_size32; 980 obj->chain_zero_gnu = obj->buckets_gnu + obj->nbuckets_gnu - 981 obj->symndx_gnu; 982 obj->valid_hash_gnu = nmw_power2 && obj->nbuckets_gnu > 0 && 983 obj->buckets_gnu != NULL; 984 } 985 break; 986 987 case DT_NEEDED: 988 if (!obj->rtld) { 989 Needed_Entry *nep = NEW(Needed_Entry); 990 nep->name = dynp->d_un.d_val; 991 nep->obj = NULL; 992 nep->next = NULL; 993 994 *needed_tail = nep; 995 needed_tail = &nep->next; 996 } 997 break; 998 999 case DT_FILTER: 1000 if (!obj->rtld) { 1001 Needed_Entry *nep = NEW(Needed_Entry); 1002 nep->name = dynp->d_un.d_val; 1003 nep->obj = NULL; 1004 nep->next = NULL; 1005 1006 *needed_filtees_tail = nep; 1007 needed_filtees_tail = &nep->next; 1008 } 1009 break; 1010 1011 case DT_AUXILIARY: 1012 if (!obj->rtld) { 1013 Needed_Entry *nep = NEW(Needed_Entry); 1014 nep->name = dynp->d_un.d_val; 1015 nep->obj = NULL; 1016 nep->next = NULL; 1017 1018 *needed_aux_filtees_tail = nep; 1019 needed_aux_filtees_tail = &nep->next; 1020 } 1021 break; 1022 1023 case DT_PLTGOT: 1024 obj->pltgot = (Elf_Addr *) (obj->relocbase + dynp->d_un.d_ptr); 1025 break; 1026 1027 case DT_TEXTREL: 1028 obj->textrel = true; 1029 break; 1030 1031 case DT_SYMBOLIC: 1032 obj->symbolic = true; 1033 break; 1034 1035 case DT_RPATH: 1036 /* 1037 * We have to wait until later to process this, because we 1038 * might not have gotten the address of the string table yet. 1039 */ 1040 *dyn_rpath = dynp; 1041 break; 1042 1043 case DT_SONAME: 1044 *dyn_soname = dynp; 1045 break; 1046 1047 case DT_RUNPATH: 1048 *dyn_runpath = dynp; 1049 break; 1050 1051 case DT_INIT: 1052 obj->init = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr); 1053 break; 1054 1055 case DT_PREINIT_ARRAY: 1056 obj->preinit_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1057 break; 1058 1059 case DT_PREINIT_ARRAYSZ: 1060 obj->preinit_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1061 break; 1062 1063 case DT_INIT_ARRAY: 1064 obj->init_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1065 break; 1066 1067 case DT_INIT_ARRAYSZ: 1068 obj->init_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1069 break; 1070 1071 case DT_FINI: 1072 obj->fini = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr); 1073 break; 1074 1075 case DT_FINI_ARRAY: 1076 obj->fini_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1077 break; 1078 1079 case DT_FINI_ARRAYSZ: 1080 obj->fini_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1081 break; 1082 1083 /* 1084 * Don't process DT_DEBUG on MIPS as the dynamic section 1085 * is mapped read-only. DT_MIPS_RLD_MAP is used instead. 1086 */ 1087 1088#ifndef __mips__ 1089 case DT_DEBUG: 1090 /* XXX - not implemented yet */ 1091 if (!early) 1092 dbg("Filling in DT_DEBUG entry"); 1093 ((Elf_Dyn*)dynp)->d_un.d_ptr = (Elf_Addr) &r_debug; 1094 break; 1095#endif 1096 1097 case DT_FLAGS: 1098 if ((dynp->d_un.d_val & DF_ORIGIN) && trust) 1099 obj->z_origin = true; 1100 if (dynp->d_un.d_val & DF_SYMBOLIC) 1101 obj->symbolic = true; 1102 if (dynp->d_un.d_val & DF_TEXTREL) 1103 obj->textrel = true; 1104 if (dynp->d_un.d_val & DF_BIND_NOW) 1105 obj->bind_now = true; 1106 /*if (dynp->d_un.d_val & DF_STATIC_TLS) 1107 ;*/ 1108 break; 1109#ifdef __mips__ 1110 case DT_MIPS_LOCAL_GOTNO: 1111 obj->local_gotno = dynp->d_un.d_val; 1112 break; 1113 1114 case DT_MIPS_SYMTABNO: 1115 obj->symtabno = dynp->d_un.d_val; 1116 break; 1117 1118 case DT_MIPS_GOTSYM: 1119 obj->gotsym = dynp->d_un.d_val; 1120 break; 1121 1122 case DT_MIPS_RLD_MAP: 1123 *((Elf_Addr *)(dynp->d_un.d_ptr)) = (Elf_Addr) &r_debug; 1124 break; 1125#endif 1126 1127 case DT_FLAGS_1: 1128 if (dynp->d_un.d_val & DF_1_NOOPEN) 1129 obj->z_noopen = true; 1130 if ((dynp->d_un.d_val & DF_1_ORIGIN) && trust) 1131 obj->z_origin = true; 1132 /*if (dynp->d_un.d_val & DF_1_GLOBAL) 1133 XXX ;*/ 1134 if (dynp->d_un.d_val & DF_1_BIND_NOW) 1135 obj->bind_now = true; 1136 if (dynp->d_un.d_val & DF_1_NODELETE) 1137 obj->z_nodelete = true; 1138 if (dynp->d_un.d_val & DF_1_LOADFLTR) 1139 obj->z_loadfltr = true; 1140 if (dynp->d_un.d_val & DF_1_INTERPOSE) 1141 obj->z_interpose = true; 1142 if (dynp->d_un.d_val & DF_1_NODEFLIB) 1143 obj->z_nodeflib = true; 1144 break; 1145 1146 default: 1147 if (!early) { 1148 dbg("Ignoring d_tag %ld = %#lx", (long)dynp->d_tag, 1149 (long)dynp->d_tag); 1150 } 1151 break; 1152 } 1153 } 1154 1155 obj->traced = false; 1156 1157 if (plttype == DT_RELA) { 1158 obj->pltrela = (const Elf_Rela *) obj->pltrel; 1159 obj->pltrel = NULL; 1160 obj->pltrelasize = obj->pltrelsize; 1161 obj->pltrelsize = 0; 1162 } 1163 1164 /* Determine size of dynsym table (equal to nchains of sysv hash) */ 1165 if (obj->valid_hash_sysv) 1166 obj->dynsymcount = obj->nchains; 1167 else if (obj->valid_hash_gnu) { 1168 obj->dynsymcount = 0; 1169 for (bkt = 0; bkt < obj->nbuckets_gnu; bkt++) { 1170 if (obj->buckets_gnu[bkt] == 0) 1171 continue; 1172 hashval = &obj->chain_zero_gnu[obj->buckets_gnu[bkt]]; 1173 do 1174 obj->dynsymcount++; 1175 while ((*hashval++ & 1u) == 0); 1176 } 1177 obj->dynsymcount += obj->symndx_gnu; 1178 } 1179} 1180 1181static void 1182digest_dynamic2(Obj_Entry *obj, const Elf_Dyn *dyn_rpath, 1183 const Elf_Dyn *dyn_soname, const Elf_Dyn *dyn_runpath) 1184{ 1185 1186 if (obj->z_origin && obj->origin_path == NULL) { 1187 obj->origin_path = xmalloc(PATH_MAX); 1188 if (rtld_dirname_abs(obj->path, obj->origin_path) == -1) 1189 die(); 1190 } 1191 1192 if (dyn_runpath != NULL) { 1193 obj->runpath = (char *)obj->strtab + dyn_runpath->d_un.d_val; 1194 if (obj->z_origin) 1195 obj->runpath = origin_subst(obj->runpath, obj->origin_path); 1196 } 1197 else if (dyn_rpath != NULL) { 1198 obj->rpath = (char *)obj->strtab + dyn_rpath->d_un.d_val; 1199 if (obj->z_origin) 1200 obj->rpath = origin_subst(obj->rpath, obj->origin_path); 1201 } 1202 1203 if (dyn_soname != NULL) 1204 object_add_name(obj, obj->strtab + dyn_soname->d_un.d_val); 1205} 1206 1207static void 1208digest_dynamic(Obj_Entry *obj, int early) 1209{ 1210 const Elf_Dyn *dyn_rpath; 1211 const Elf_Dyn *dyn_soname; 1212 const Elf_Dyn *dyn_runpath; 1213 1214 digest_dynamic1(obj, early, &dyn_rpath, &dyn_soname, &dyn_runpath); 1215 digest_dynamic2(obj, dyn_rpath, dyn_soname, dyn_runpath); 1216} 1217 1218/* 1219 * Process a shared object's program header. This is used only for the 1220 * main program, when the kernel has already loaded the main program 1221 * into memory before calling the dynamic linker. It creates and 1222 * returns an Obj_Entry structure. 1223 */ 1224static Obj_Entry * 1225digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path) 1226{ 1227 Obj_Entry *obj; 1228 const Elf_Phdr *phlimit = phdr + phnum; 1229 const Elf_Phdr *ph; 1230 Elf_Addr note_start, note_end; 1231 int nsegs = 0; 1232 1233 obj = obj_new(); 1234 for (ph = phdr; ph < phlimit; ph++) { 1235 if (ph->p_type != PT_PHDR) 1236 continue; 1237 1238 obj->phdr = phdr; 1239 obj->phsize = ph->p_memsz; 1240 obj->relocbase = (caddr_t)phdr - ph->p_vaddr; 1241 break; 1242 } 1243 1244 obj->stack_flags = PF_X | PF_R | PF_W; 1245 1246 for (ph = phdr; ph < phlimit; ph++) { 1247 switch (ph->p_type) { 1248 1249 case PT_INTERP: 1250 obj->interp = (const char *)(ph->p_vaddr + obj->relocbase); 1251 break; 1252 1253 case PT_LOAD: 1254 if (nsegs == 0) { /* First load segment */ 1255 obj->vaddrbase = trunc_page(ph->p_vaddr); 1256 obj->mapbase = obj->vaddrbase + obj->relocbase; 1257 obj->textsize = round_page(ph->p_vaddr + ph->p_memsz) - 1258 obj->vaddrbase; 1259 } else { /* Last load segment */ 1260 obj->mapsize = round_page(ph->p_vaddr + ph->p_memsz) - 1261 obj->vaddrbase; 1262 } 1263 nsegs++; 1264 break; 1265 1266 case PT_DYNAMIC: 1267 obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + obj->relocbase); 1268 break; 1269 1270 case PT_TLS: 1271 obj->tlsindex = 1; 1272 obj->tlssize = ph->p_memsz; 1273 obj->tlsalign = ph->p_align; 1274 obj->tlsinitsize = ph->p_filesz; 1275 obj->tlsinit = (void*)(ph->p_vaddr + obj->relocbase); 1276 break; 1277 1278 case PT_GNU_STACK: 1279 obj->stack_flags = ph->p_flags; 1280 break; 1281 1282 case PT_GNU_RELRO: 1283 obj->relro_page = obj->relocbase + trunc_page(ph->p_vaddr); 1284 obj->relro_size = round_page(ph->p_memsz); 1285 break; 1286 1287 case PT_NOTE: 1288 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; 1289 note_end = note_start + ph->p_filesz; 1290 digest_notes(obj, note_start, note_end); 1291 break; 1292 } 1293 } 1294 if (nsegs < 1) { 1295 _rtld_error("%s: too few PT_LOAD segments", path); 1296 return NULL; 1297 } 1298 1299 obj->entry = entry; 1300 return obj; 1301} 1302 1303void 1304digest_notes(Obj_Entry *obj, Elf_Addr note_start, Elf_Addr note_end) 1305{ 1306 const Elf_Note *note; 1307 const char *note_name; 1308 uintptr_t p; 1309 1310 for (note = (const Elf_Note *)note_start; (Elf_Addr)note < note_end; 1311 note = (const Elf_Note *)((const char *)(note + 1) + 1312 roundup2(note->n_namesz, sizeof(Elf32_Addr)) + 1313 roundup2(note->n_descsz, sizeof(Elf32_Addr)))) { 1314 if (note->n_namesz != sizeof(NOTE_FREEBSD_VENDOR) || 1315 note->n_descsz != sizeof(int32_t)) 1316 continue; 1317 if (note->n_type != ABI_NOTETYPE && 1318 note->n_type != CRT_NOINIT_NOTETYPE) 1319 continue; 1320 note_name = (const char *)(note + 1); 1321 if (strncmp(NOTE_FREEBSD_VENDOR, note_name, 1322 sizeof(NOTE_FREEBSD_VENDOR)) != 0) 1323 continue; 1324 switch (note->n_type) { 1325 case ABI_NOTETYPE: 1326 /* FreeBSD osrel note */ 1327 p = (uintptr_t)(note + 1); 1328 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1329 obj->osrel = *(const int32_t *)(p); 1330 dbg("note osrel %d", obj->osrel); 1331 break; 1332 case CRT_NOINIT_NOTETYPE: 1333 /* FreeBSD 'crt does not call init' note */ 1334 obj->crt_no_init = true; 1335 dbg("note crt_no_init"); 1336 break; 1337 } 1338 } 1339} 1340 1341static Obj_Entry * 1342dlcheck(void *handle) 1343{ 1344 Obj_Entry *obj; 1345 1346 for (obj = obj_list; obj != NULL; obj = obj->next) 1347 if (obj == (Obj_Entry *) handle) 1348 break; 1349 1350 if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) { 1351 _rtld_error("Invalid shared object handle %p", handle); 1352 return NULL; 1353 } 1354 return obj; 1355} 1356 1357/* 1358 * If the given object is already in the donelist, return true. Otherwise 1359 * add the object to the list and return false. 1360 */ 1361static bool 1362donelist_check(DoneList *dlp, const Obj_Entry *obj) 1363{ 1364 unsigned int i; 1365 1366 for (i = 0; i < dlp->num_used; i++) 1367 if (dlp->objs[i] == obj) 1368 return true; 1369 /* 1370 * Our donelist allocation should always be sufficient. But if 1371 * our threads locking isn't working properly, more shared objects 1372 * could have been loaded since we allocated the list. That should 1373 * never happen, but we'll handle it properly just in case it does. 1374 */ 1375 if (dlp->num_used < dlp->num_alloc) 1376 dlp->objs[dlp->num_used++] = obj; 1377 return false; 1378} 1379 1380/* 1381 * Hash function for symbol table lookup. Don't even think about changing 1382 * this. It is specified by the System V ABI. 1383 */ 1384unsigned long 1385elf_hash(const char *name) 1386{ 1387 const unsigned char *p = (const unsigned char *) name; 1388 unsigned long h = 0; 1389 unsigned long g; 1390 1391 while (*p != '\0') { 1392 h = (h << 4) + *p++; 1393 if ((g = h & 0xf0000000) != 0) 1394 h ^= g >> 24; 1395 h &= ~g; 1396 } 1397 return h; 1398} 1399 1400/* 1401 * The GNU hash function is the Daniel J. Bernstein hash clipped to 32 bits 1402 * unsigned in case it's implemented with a wider type. 1403 */ 1404static uint32_t 1405gnu_hash(const char *s) 1406{ 1407 uint32_t h; 1408 unsigned char c; 1409 1410 h = 5381; 1411 for (c = *s; c != '\0'; c = *++s) 1412 h = h * 33 + c; 1413 return (h & 0xffffffff); 1414} 1415 1416/* 1417 * Find the library with the given name, and return its full pathname. 1418 * The returned string is dynamically allocated. Generates an error 1419 * message and returns NULL if the library cannot be found. 1420 * 1421 * If the second argument is non-NULL, then it refers to an already- 1422 * loaded shared object, whose library search path will be searched. 1423 * 1424 * The search order is: 1425 * DT_RPATH in the referencing file _unless_ DT_RUNPATH is present (1) 1426 * DT_RPATH of the main object if DSO without defined DT_RUNPATH (1) 1427 * LD_LIBRARY_PATH 1428 * DT_RUNPATH in the referencing file 1429 * ldconfig hints (if -z nodefaultlib, filter out default library directories 1430 * from list) 1431 * /lib:/usr/lib _unless_ the referencing file is linked with -z nodefaultlib 1432 * 1433 * (1) Handled in digest_dynamic2 - rpath left NULL if runpath defined. 1434 */ 1435static char * 1436find_library(const char *xname, const Obj_Entry *refobj) 1437{ 1438 char *pathname; 1439 char *name; 1440 bool nodeflib, objgiven; 1441 1442 objgiven = refobj != NULL; 1443 if (strchr(xname, '/') != NULL) { /* Hard coded pathname */ 1444 if (xname[0] != '/' && !trust) { 1445 _rtld_error("Absolute pathname required for shared object \"%s\"", 1446 xname); 1447 return NULL; 1448 } 1449 if (objgiven && refobj->z_origin) { 1450 return (origin_subst(__DECONST(char *, xname), 1451 refobj->origin_path)); 1452 } else { 1453 return (xstrdup(xname)); 1454 } 1455 } 1456 1457 if (libmap_disable || !objgiven || 1458 (name = lm_find(refobj->path, xname)) == NULL) 1459 name = (char *)xname; 1460 1461 dbg(" Searching for \"%s\"", name); 1462 1463 /* 1464 * If refobj->rpath != NULL, then refobj->runpath is NULL. Fall 1465 * back to pre-conforming behaviour if user requested so with 1466 * LD_LIBRARY_PATH_RPATH environment variable and ignore -z 1467 * nodeflib. 1468 */ 1469 if (objgiven && refobj->rpath != NULL && ld_library_path_rpath) { 1470 if ((pathname = search_library_path(name, ld_library_path)) != NULL || 1471 (refobj != NULL && 1472 (pathname = search_library_path(name, refobj->rpath)) != NULL) || 1473 (pathname = search_library_path(name, gethints(false))) != NULL || 1474 (pathname = search_library_path(name, STANDARD_LIBRARY_PATH)) != NULL) 1475 return (pathname); 1476 } else { 1477 nodeflib = objgiven ? refobj->z_nodeflib : false; 1478 if ((objgiven && 1479 (pathname = search_library_path(name, refobj->rpath)) != NULL) || 1480 (objgiven && refobj->runpath == NULL && refobj != obj_main && 1481 (pathname = search_library_path(name, obj_main->rpath)) != NULL) || 1482 (pathname = search_library_path(name, ld_library_path)) != NULL || 1483 (objgiven && 1484 (pathname = search_library_path(name, refobj->runpath)) != NULL) || 1485 (pathname = search_library_path(name, gethints(nodeflib))) != NULL || 1486 (objgiven && !nodeflib && 1487 (pathname = search_library_path(name, STANDARD_LIBRARY_PATH)) != NULL)) 1488 return (pathname); 1489 } 1490 1491 if (objgiven && refobj->path != NULL) { 1492 _rtld_error("Shared object \"%s\" not found, required by \"%s\"", 1493 name, basename(refobj->path)); 1494 } else { 1495 _rtld_error("Shared object \"%s\" not found", name); 1496 } 1497 return NULL; 1498} 1499 1500/* 1501 * Given a symbol number in a referencing object, find the corresponding 1502 * definition of the symbol. Returns a pointer to the symbol, or NULL if 1503 * no definition was found. Returns a pointer to the Obj_Entry of the 1504 * defining object via the reference parameter DEFOBJ_OUT. 1505 */ 1506const Elf_Sym * 1507find_symdef(unsigned long symnum, const Obj_Entry *refobj, 1508 const Obj_Entry **defobj_out, int flags, SymCache *cache, 1509 RtldLockState *lockstate) 1510{ 1511 const Elf_Sym *ref; 1512 const Elf_Sym *def; 1513 const Obj_Entry *defobj; 1514 SymLook req; 1515 const char *name; 1516 int res; 1517 1518 /* 1519 * If we have already found this symbol, get the information from 1520 * the cache. 1521 */ 1522 if (symnum >= refobj->dynsymcount) 1523 return NULL; /* Bad object */ 1524 if (cache != NULL && cache[symnum].sym != NULL) { 1525 *defobj_out = cache[symnum].obj; 1526 return cache[symnum].sym; 1527 } 1528 1529 ref = refobj->symtab + symnum; 1530 name = refobj->strtab + ref->st_name; 1531 def = NULL; 1532 defobj = NULL; 1533 1534 /* 1535 * We don't have to do a full scale lookup if the symbol is local. 1536 * We know it will bind to the instance in this load module; to 1537 * which we already have a pointer (ie ref). By not doing a lookup, 1538 * we not only improve performance, but it also avoids unresolvable 1539 * symbols when local symbols are not in the hash table. This has 1540 * been seen with the ia64 toolchain. 1541 */ 1542 if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) { 1543 if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) { 1544 _rtld_error("%s: Bogus symbol table entry %lu", refobj->path, 1545 symnum); 1546 } 1547 symlook_init(&req, name); 1548 req.flags = flags; 1549 req.ventry = fetch_ventry(refobj, symnum); 1550 req.lockstate = lockstate; 1551 res = symlook_default(&req, refobj); 1552 if (res == 0) { 1553 def = req.sym_out; 1554 defobj = req.defobj_out; 1555 } 1556 } else { 1557 def = ref; 1558 defobj = refobj; 1559 } 1560 1561 /* 1562 * If we found no definition and the reference is weak, treat the 1563 * symbol as having the value zero. 1564 */ 1565 if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) { 1566 def = &sym_zero; 1567 defobj = obj_main; 1568 } 1569 1570 if (def != NULL) { 1571 *defobj_out = defobj; 1572 /* Record the information in the cache to avoid subsequent lookups. */ 1573 if (cache != NULL) { 1574 cache[symnum].sym = def; 1575 cache[symnum].obj = defobj; 1576 } 1577 } else { 1578 if (refobj != &obj_rtld) 1579 _rtld_error("%s: Undefined symbol \"%s\"", refobj->path, name); 1580 } 1581 return def; 1582} 1583 1584/* 1585 * Return the search path from the ldconfig hints file, reading it if 1586 * necessary. If nostdlib is true, then the default search paths are 1587 * not added to result. 1588 * 1589 * Returns NULL if there are problems with the hints file, 1590 * or if the search path there is empty. 1591 */ 1592static const char * 1593gethints(bool nostdlib) 1594{ 1595 static char *hints, *filtered_path; 1596 struct elfhints_hdr hdr; 1597 struct fill_search_info_args sargs, hargs; 1598 struct dl_serinfo smeta, hmeta, *SLPinfo, *hintinfo; 1599 struct dl_serpath *SLPpath, *hintpath; 1600 char *p; 1601 unsigned int SLPndx, hintndx, fndx, fcount; 1602 int fd; 1603 size_t flen; 1604 bool skip; 1605 1606 /* First call, read the hints file */ 1607 if (hints == NULL) { 1608 /* Keep from trying again in case the hints file is bad. */ 1609 hints = ""; 1610 1611 if ((fd = open(ld_elf_hints_path, O_RDONLY | O_CLOEXEC)) == -1) 1612 return (NULL); 1613 if (read(fd, &hdr, sizeof hdr) != sizeof hdr || 1614 hdr.magic != ELFHINTS_MAGIC || 1615 hdr.version != 1) { 1616 close(fd); 1617 return (NULL); 1618 } 1619 p = xmalloc(hdr.dirlistlen + 1); 1620 if (lseek(fd, hdr.strtab + hdr.dirlist, SEEK_SET) == -1 || 1621 read(fd, p, hdr.dirlistlen + 1) != 1622 (ssize_t)hdr.dirlistlen + 1) { 1623 free(p); 1624 close(fd); 1625 return (NULL); 1626 } 1627 hints = p; 1628 close(fd); 1629 } 1630 1631 /* 1632 * If caller agreed to receive list which includes the default 1633 * paths, we are done. Otherwise, if we still did not 1634 * calculated filtered result, do it now. 1635 */ 1636 if (!nostdlib) 1637 return (hints[0] != '\0' ? hints : NULL); 1638 if (filtered_path != NULL) 1639 goto filt_ret; 1640 1641 /* 1642 * Obtain the list of all configured search paths, and the 1643 * list of the default paths. 1644 * 1645 * First estimate the size of the results. 1646 */ 1647 smeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 1648 smeta.dls_cnt = 0; 1649 hmeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 1650 hmeta.dls_cnt = 0; 1651 1652 sargs.request = RTLD_DI_SERINFOSIZE; 1653 sargs.serinfo = &smeta; 1654 hargs.request = RTLD_DI_SERINFOSIZE; 1655 hargs.serinfo = &hmeta; 1656 1657 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &sargs); 1658 path_enumerate(p, fill_search_info, &hargs); 1659 1660 SLPinfo = xmalloc(smeta.dls_size); 1661 hintinfo = xmalloc(hmeta.dls_size); 1662 1663 /* 1664 * Next fetch both sets of paths. 1665 */ 1666 sargs.request = RTLD_DI_SERINFO; 1667 sargs.serinfo = SLPinfo; 1668 sargs.serpath = &SLPinfo->dls_serpath[0]; 1669 sargs.strspace = (char *)&SLPinfo->dls_serpath[smeta.dls_cnt]; 1670 1671 hargs.request = RTLD_DI_SERINFO; 1672 hargs.serinfo = hintinfo; 1673 hargs.serpath = &hintinfo->dls_serpath[0]; 1674 hargs.strspace = (char *)&hintinfo->dls_serpath[hmeta.dls_cnt]; 1675 1676 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &sargs); 1677 path_enumerate(p, fill_search_info, &hargs); 1678 1679 /* 1680 * Now calculate the difference between two sets, by excluding 1681 * standard paths from the full set. 1682 */ 1683 fndx = 0; 1684 fcount = 0; 1685 filtered_path = xmalloc(hdr.dirlistlen + 1); 1686 hintpath = &hintinfo->dls_serpath[0]; 1687 for (hintndx = 0; hintndx < hmeta.dls_cnt; hintndx++, hintpath++) { 1688 skip = false; 1689 SLPpath = &SLPinfo->dls_serpath[0]; 1690 /* 1691 * Check each standard path against current. 1692 */ 1693 for (SLPndx = 0; SLPndx < smeta.dls_cnt; SLPndx++, SLPpath++) { 1694 /* matched, skip the path */ 1695 if (!strcmp(hintpath->dls_name, SLPpath->dls_name)) { 1696 skip = true; 1697 break; 1698 } 1699 } 1700 if (skip) 1701 continue; 1702 /* 1703 * Not matched against any standard path, add the path 1704 * to result. Separate consequtive paths with ':'. 1705 */ 1706 if (fcount > 0) { 1707 filtered_path[fndx] = ':'; 1708 fndx++; 1709 } 1710 fcount++; 1711 flen = strlen(hintpath->dls_name); 1712 strncpy((filtered_path + fndx), hintpath->dls_name, flen); 1713 fndx += flen; 1714 } 1715 filtered_path[fndx] = '\0'; 1716 1717 free(SLPinfo); 1718 free(hintinfo); 1719 1720filt_ret: 1721 return (filtered_path[0] != '\0' ? filtered_path : NULL); 1722} 1723 1724static void 1725init_dag(Obj_Entry *root) 1726{ 1727 const Needed_Entry *needed; 1728 const Objlist_Entry *elm; 1729 DoneList donelist; 1730 1731 if (root->dag_inited) 1732 return; 1733 donelist_init(&donelist); 1734 1735 /* Root object belongs to own DAG. */ 1736 objlist_push_tail(&root->dldags, root); 1737 objlist_push_tail(&root->dagmembers, root); 1738 donelist_check(&donelist, root); 1739 1740 /* 1741 * Add dependencies of root object to DAG in breadth order 1742 * by exploiting the fact that each new object get added 1743 * to the tail of the dagmembers list. 1744 */ 1745 STAILQ_FOREACH(elm, &root->dagmembers, link) { 1746 for (needed = elm->obj->needed; needed != NULL; needed = needed->next) { 1747 if (needed->obj == NULL || donelist_check(&donelist, needed->obj)) 1748 continue; 1749 objlist_push_tail(&needed->obj->dldags, root); 1750 objlist_push_tail(&root->dagmembers, needed->obj); 1751 } 1752 } 1753 root->dag_inited = true; 1754} 1755 1756static void 1757process_nodelete(Obj_Entry *root) 1758{ 1759 const Objlist_Entry *elm; 1760 1761 /* 1762 * Walk over object DAG and process every dependent object that 1763 * is marked as DF_1_NODELETE. They need to grow their own DAG, 1764 * which then should have its reference upped separately. 1765 */ 1766 STAILQ_FOREACH(elm, &root->dagmembers, link) { 1767 if (elm->obj != NULL && elm->obj->z_nodelete && 1768 !elm->obj->ref_nodel) { 1769 dbg("obj %s nodelete", elm->obj->path); 1770 init_dag(elm->obj); 1771 ref_dag(elm->obj); 1772 elm->obj->ref_nodel = true; 1773 } 1774 } 1775} 1776/* 1777 * Initialize the dynamic linker. The argument is the address at which 1778 * the dynamic linker has been mapped into memory. The primary task of 1779 * this function is to relocate the dynamic linker. 1780 */ 1781static void 1782init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info) 1783{ 1784 Obj_Entry objtmp; /* Temporary rtld object */ 1785 const Elf_Dyn *dyn_rpath; 1786 const Elf_Dyn *dyn_soname; 1787 const Elf_Dyn *dyn_runpath; 1788 1789 /* 1790 * Conjure up an Obj_Entry structure for the dynamic linker. 1791 * 1792 * The "path" member can't be initialized yet because string constants 1793 * cannot yet be accessed. Below we will set it correctly. 1794 */ 1795 memset(&objtmp, 0, sizeof(objtmp)); 1796 objtmp.path = NULL; 1797 objtmp.rtld = true; 1798 objtmp.mapbase = mapbase; 1799#ifdef PIC 1800 objtmp.relocbase = mapbase; 1801#endif 1802 if (RTLD_IS_DYNAMIC()) { 1803 objtmp.dynamic = rtld_dynamic(&objtmp); 1804 digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname, &dyn_runpath); 1805 assert(objtmp.needed == NULL); 1806#if !defined(__mips__) 1807 /* MIPS has a bogus DT_TEXTREL. */ 1808 assert(!objtmp.textrel); 1809#endif 1810 1811 /* 1812 * Temporarily put the dynamic linker entry into the object list, so 1813 * that symbols can be found. 1814 */ 1815 1816 relocate_objects(&objtmp, true, &objtmp, 0, NULL); 1817 } 1818 1819 /* Initialize the object list. */ 1820 obj_tail = &obj_list; 1821 1822 /* Now that non-local variables can be accesses, copy out obj_rtld. */ 1823 memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld)); 1824 1825 if (aux_info[AT_PAGESZ] != NULL) 1826 pagesize = aux_info[AT_PAGESZ]->a_un.a_val; 1827 if (aux_info[AT_OSRELDATE] != NULL) 1828 osreldate = aux_info[AT_OSRELDATE]->a_un.a_val; 1829 1830 digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname, dyn_runpath); 1831 1832 /* Replace the path with a dynamically allocated copy. */ 1833 obj_rtld.path = xstrdup(PATH_RTLD); 1834 1835 r_debug.r_brk = r_debug_state; 1836 r_debug.r_state = RT_CONSISTENT; 1837} 1838 1839/* 1840 * Add the init functions from a needed object list (and its recursive 1841 * needed objects) to "list". This is not used directly; it is a helper 1842 * function for initlist_add_objects(). The write lock must be held 1843 * when this function is called. 1844 */ 1845static void 1846initlist_add_neededs(Needed_Entry *needed, Objlist *list) 1847{ 1848 /* Recursively process the successor needed objects. */ 1849 if (needed->next != NULL) 1850 initlist_add_neededs(needed->next, list); 1851 1852 /* Process the current needed object. */ 1853 if (needed->obj != NULL) 1854 initlist_add_objects(needed->obj, &needed->obj->next, list); 1855} 1856 1857/* 1858 * Scan all of the DAGs rooted in the range of objects from "obj" to 1859 * "tail" and add their init functions to "list". This recurses over 1860 * the DAGs and ensure the proper init ordering such that each object's 1861 * needed libraries are initialized before the object itself. At the 1862 * same time, this function adds the objects to the global finalization 1863 * list "list_fini" in the opposite order. The write lock must be 1864 * held when this function is called. 1865 */ 1866static void 1867initlist_add_objects(Obj_Entry *obj, Obj_Entry **tail, Objlist *list) 1868{ 1869 1870 if (obj->init_scanned || obj->init_done) 1871 return; 1872 obj->init_scanned = true; 1873 1874 /* Recursively process the successor objects. */ 1875 if (&obj->next != tail) 1876 initlist_add_objects(obj->next, tail, list); 1877 1878 /* Recursively process the needed objects. */ 1879 if (obj->needed != NULL) 1880 initlist_add_neededs(obj->needed, list); 1881 if (obj->needed_filtees != NULL) 1882 initlist_add_neededs(obj->needed_filtees, list); 1883 if (obj->needed_aux_filtees != NULL) 1884 initlist_add_neededs(obj->needed_aux_filtees, list); 1885 1886 /* Add the object to the init list. */ 1887 if (obj->preinit_array != (Elf_Addr)NULL || obj->init != (Elf_Addr)NULL || 1888 obj->init_array != (Elf_Addr)NULL) 1889 objlist_push_tail(list, obj); 1890 1891 /* Add the object to the global fini list in the reverse order. */ 1892 if ((obj->fini != (Elf_Addr)NULL || obj->fini_array != (Elf_Addr)NULL) 1893 && !obj->on_fini_list) { 1894 objlist_push_head(&list_fini, obj); 1895 obj->on_fini_list = true; 1896 } 1897} 1898 1899#ifndef FPTR_TARGET 1900#define FPTR_TARGET(f) ((Elf_Addr) (f)) 1901#endif 1902 1903static void 1904free_needed_filtees(Needed_Entry *n) 1905{ 1906 Needed_Entry *needed, *needed1; 1907 1908 for (needed = n; needed != NULL; needed = needed->next) { 1909 if (needed->obj != NULL) { 1910 dlclose(needed->obj); 1911 needed->obj = NULL; 1912 } 1913 } 1914 for (needed = n; needed != NULL; needed = needed1) { 1915 needed1 = needed->next; 1916 free(needed); 1917 } 1918} 1919 1920static void 1921unload_filtees(Obj_Entry *obj) 1922{ 1923 1924 free_needed_filtees(obj->needed_filtees); 1925 obj->needed_filtees = NULL; 1926 free_needed_filtees(obj->needed_aux_filtees); 1927 obj->needed_aux_filtees = NULL; 1928 obj->filtees_loaded = false; 1929} 1930 1931static void 1932load_filtee1(Obj_Entry *obj, Needed_Entry *needed, int flags, 1933 RtldLockState *lockstate) 1934{ 1935 1936 for (; needed != NULL; needed = needed->next) { 1937 needed->obj = dlopen_object(obj->strtab + needed->name, -1, obj, 1938 flags, ((ld_loadfltr || obj->z_loadfltr) ? RTLD_NOW : RTLD_LAZY) | 1939 RTLD_LOCAL, lockstate); 1940 } 1941} 1942 1943static void 1944load_filtees(Obj_Entry *obj, int flags, RtldLockState *lockstate) 1945{ 1946 1947 lock_restart_for_upgrade(lockstate); 1948 if (!obj->filtees_loaded) { 1949 load_filtee1(obj, obj->needed_filtees, flags, lockstate); 1950 load_filtee1(obj, obj->needed_aux_filtees, flags, lockstate); 1951 obj->filtees_loaded = true; 1952 } 1953} 1954 1955static int 1956process_needed(Obj_Entry *obj, Needed_Entry *needed, int flags) 1957{ 1958 Obj_Entry *obj1; 1959 1960 for (; needed != NULL; needed = needed->next) { 1961 obj1 = needed->obj = load_object(obj->strtab + needed->name, -1, obj, 1962 flags & ~RTLD_LO_NOLOAD); 1963 if (obj1 == NULL && !ld_tracing && (flags & RTLD_LO_FILTEES) == 0) 1964 return (-1); 1965 } 1966 return (0); 1967} 1968 1969/* 1970 * Given a shared object, traverse its list of needed objects, and load 1971 * each of them. Returns 0 on success. Generates an error message and 1972 * returns -1 on failure. 1973 */ 1974static int 1975load_needed_objects(Obj_Entry *first, int flags) 1976{ 1977 Obj_Entry *obj; 1978 1979 for (obj = first; obj != NULL; obj = obj->next) { 1980 if (process_needed(obj, obj->needed, flags) == -1) 1981 return (-1); 1982 } 1983 return (0); 1984} 1985 1986static int 1987load_preload_objects(void) 1988{ 1989 char *p = ld_preload; 1990 Obj_Entry *obj; 1991 static const char delim[] = " \t:;"; 1992 1993 if (p == NULL) 1994 return 0; 1995 1996 p += strspn(p, delim); 1997 while (*p != '\0') { 1998 size_t len = strcspn(p, delim); 1999 char savech; 2000 2001 savech = p[len]; 2002 p[len] = '\0'; 2003 obj = load_object(p, -1, NULL, 0); 2004 if (obj == NULL) 2005 return -1; /* XXX - cleanup */ 2006 obj->z_interpose = true; 2007 p[len] = savech; 2008 p += len; 2009 p += strspn(p, delim); 2010 } 2011 LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL); 2012 return 0; 2013} 2014 2015static const char * 2016printable_path(const char *path) 2017{ 2018 2019 return (path == NULL ? "<unknown>" : path); 2020} 2021 2022/* 2023 * Load a shared object into memory, if it is not already loaded. The 2024 * object may be specified by name or by user-supplied file descriptor 2025 * fd_u. In the later case, the fd_u descriptor is not closed, but its 2026 * duplicate is. 2027 * 2028 * Returns a pointer to the Obj_Entry for the object. Returns NULL 2029 * on failure. 2030 */ 2031static Obj_Entry * 2032load_object(const char *name, int fd_u, const Obj_Entry *refobj, int flags) 2033{ 2034 Obj_Entry *obj; 2035 int fd; 2036 struct stat sb; 2037 char *path; 2038 2039 if (name != NULL) { 2040 for (obj = obj_list->next; obj != NULL; obj = obj->next) { 2041 if (object_match_name(obj, name)) 2042 return (obj); 2043 } 2044 2045 path = find_library(name, refobj); 2046 if (path == NULL) 2047 return (NULL); 2048 } else 2049 path = NULL; 2050 2051 /* 2052 * If we didn't find a match by pathname, or the name is not 2053 * supplied, open the file and check again by device and inode. 2054 * This avoids false mismatches caused by multiple links or ".." 2055 * in pathnames. 2056 * 2057 * To avoid a race, we open the file and use fstat() rather than 2058 * using stat(). 2059 */ 2060 fd = -1; 2061 if (fd_u == -1) { 2062 if ((fd = open(path, O_RDONLY | O_CLOEXEC)) == -1) { 2063 _rtld_error("Cannot open \"%s\"", path); 2064 free(path); 2065 return (NULL); 2066 } 2067 } else { 2068 fd = fcntl(fd_u, F_DUPFD_CLOEXEC, 0); 2069 if (fd == -1) { 2070 _rtld_error("Cannot dup fd"); 2071 free(path); 2072 return (NULL); 2073 } 2074 } 2075 if (fstat(fd, &sb) == -1) { 2076 _rtld_error("Cannot fstat \"%s\"", printable_path(path)); 2077 close(fd); 2078 free(path); 2079 return NULL; 2080 } 2081 for (obj = obj_list->next; obj != NULL; obj = obj->next) 2082 if (obj->ino == sb.st_ino && obj->dev == sb.st_dev) 2083 break; 2084 if (obj != NULL && name != NULL) { 2085 object_add_name(obj, name); 2086 free(path); 2087 close(fd); 2088 return obj; 2089 } 2090 if (flags & RTLD_LO_NOLOAD) { 2091 free(path); 2092 close(fd); 2093 return (NULL); 2094 } 2095 2096 /* First use of this object, so we must map it in */ 2097 obj = do_load_object(fd, name, path, &sb, flags); 2098 if (obj == NULL) 2099 free(path); 2100 close(fd); 2101 2102 return obj; 2103} 2104 2105static Obj_Entry * 2106do_load_object(int fd, const char *name, char *path, struct stat *sbp, 2107 int flags) 2108{ 2109 Obj_Entry *obj; 2110 struct statfs fs; 2111 2112 /* 2113 * but first, make sure that environment variables haven't been 2114 * used to circumvent the noexec flag on a filesystem. 2115 */ 2116 if (dangerous_ld_env) { 2117 if (fstatfs(fd, &fs) != 0) { 2118 _rtld_error("Cannot fstatfs \"%s\"", printable_path(path)); 2119 return NULL; 2120 } 2121 if (fs.f_flags & MNT_NOEXEC) { 2122 _rtld_error("Cannot execute objects on %s\n", fs.f_mntonname); 2123 return NULL; 2124 } 2125 } 2126 dbg("loading \"%s\"", printable_path(path)); 2127 obj = map_object(fd, printable_path(path), sbp); 2128 if (obj == NULL) 2129 return NULL; 2130 2131 /* 2132 * If DT_SONAME is present in the object, digest_dynamic2 already 2133 * added it to the object names. 2134 */ 2135 if (name != NULL) 2136 object_add_name(obj, name); 2137 obj->path = path; 2138 digest_dynamic(obj, 0); 2139 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", obj->path, 2140 obj->valid_hash_sysv, obj->valid_hash_gnu, obj->dynsymcount); 2141 if (obj->z_noopen && (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) == 2142 RTLD_LO_DLOPEN) { 2143 dbg("refusing to load non-loadable \"%s\"", obj->path); 2144 _rtld_error("Cannot dlopen non-loadable %s", obj->path); 2145 munmap(obj->mapbase, obj->mapsize); 2146 obj_free(obj); 2147 return (NULL); 2148 } 2149 2150 *obj_tail = obj; 2151 obj_tail = &obj->next; 2152 obj_count++; 2153 obj_loads++; 2154 linkmap_add(obj); /* for GDB & dlinfo() */ 2155 max_stack_flags |= obj->stack_flags; 2156 2157 dbg(" %p .. %p: %s", obj->mapbase, 2158 obj->mapbase + obj->mapsize - 1, obj->path); 2159 if (obj->textrel) 2160 dbg(" WARNING: %s has impure text", obj->path); 2161 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 2162 obj->path); 2163 2164 return obj; 2165} 2166 2167static Obj_Entry * 2168obj_from_addr(const void *addr) 2169{ 2170 Obj_Entry *obj; 2171 2172 for (obj = obj_list; obj != NULL; obj = obj->next) { 2173 if (addr < (void *) obj->mapbase) 2174 continue; 2175 if (addr < (void *) (obj->mapbase + obj->mapsize)) 2176 return obj; 2177 } 2178 return NULL; 2179} 2180 2181static void 2182preinit_main(void) 2183{ 2184 Elf_Addr *preinit_addr; 2185 int index; 2186 2187 preinit_addr = (Elf_Addr *)obj_main->preinit_array; 2188 if (preinit_addr == NULL) 2189 return; 2190 2191 for (index = 0; index < obj_main->preinit_array_num; index++) { 2192 if (preinit_addr[index] != 0 && preinit_addr[index] != 1) { 2193 dbg("calling preinit function for %s at %p", obj_main->path, 2194 (void *)preinit_addr[index]); 2195 LD_UTRACE(UTRACE_INIT_CALL, obj_main, (void *)preinit_addr[index], 2196 0, 0, obj_main->path); 2197 call_init_pointer(obj_main, preinit_addr[index]); 2198 } 2199 } 2200} 2201 2202/* 2203 * Call the finalization functions for each of the objects in "list" 2204 * belonging to the DAG of "root" and referenced once. If NULL "root" 2205 * is specified, every finalization function will be called regardless 2206 * of the reference count and the list elements won't be freed. All of 2207 * the objects are expected to have non-NULL fini functions. 2208 */ 2209static void 2210objlist_call_fini(Objlist *list, Obj_Entry *root, RtldLockState *lockstate) 2211{ 2212 Objlist_Entry *elm; 2213 char *saved_msg; 2214 Elf_Addr *fini_addr; 2215 int index; 2216 2217 assert(root == NULL || root->refcount == 1); 2218 2219 /* 2220 * Preserve the current error message since a fini function might 2221 * call into the dynamic linker and overwrite it. 2222 */ 2223 saved_msg = errmsg_save(); 2224 do { 2225 STAILQ_FOREACH(elm, list, link) { 2226 if (root != NULL && (elm->obj->refcount != 1 || 2227 objlist_find(&root->dagmembers, elm->obj) == NULL)) 2228 continue; 2229 /* Remove object from fini list to prevent recursive invocation. */ 2230 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 2231 /* 2232 * XXX: If a dlopen() call references an object while the 2233 * fini function is in progress, we might end up trying to 2234 * unload the referenced object in dlclose() or the object 2235 * won't be unloaded although its fini function has been 2236 * called. 2237 */ 2238 lock_release(rtld_bind_lock, lockstate); 2239 2240 /* 2241 * It is legal to have both DT_FINI and DT_FINI_ARRAY defined. 2242 * When this happens, DT_FINI_ARRAY is processed first. 2243 */ 2244 fini_addr = (Elf_Addr *)elm->obj->fini_array; 2245 if (fini_addr != NULL && elm->obj->fini_array_num > 0) { 2246 for (index = elm->obj->fini_array_num - 1; index >= 0; 2247 index--) { 2248 if (fini_addr[index] != 0 && fini_addr[index] != 1) { 2249 dbg("calling fini function for %s at %p", 2250 elm->obj->path, (void *)fini_addr[index]); 2251 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, 2252 (void *)fini_addr[index], 0, 0, elm->obj->path); 2253 call_initfini_pointer(elm->obj, fini_addr[index]); 2254 } 2255 } 2256 } 2257 if (elm->obj->fini != (Elf_Addr)NULL) { 2258 dbg("calling fini function for %s at %p", elm->obj->path, 2259 (void *)elm->obj->fini); 2260 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, (void *)elm->obj->fini, 2261 0, 0, elm->obj->path); 2262 call_initfini_pointer(elm->obj, elm->obj->fini); 2263 } 2264 wlock_acquire(rtld_bind_lock, lockstate); 2265 /* No need to free anything if process is going down. */ 2266 if (root != NULL) 2267 free(elm); 2268 /* 2269 * We must restart the list traversal after every fini call 2270 * because a dlclose() call from the fini function or from 2271 * another thread might have modified the reference counts. 2272 */ 2273 break; 2274 } 2275 } while (elm != NULL); 2276 errmsg_restore(saved_msg); 2277} 2278 2279/* 2280 * Call the initialization functions for each of the objects in 2281 * "list". All of the objects are expected to have non-NULL init 2282 * functions. 2283 */ 2284static void 2285objlist_call_init(Objlist *list, RtldLockState *lockstate) 2286{ 2287 Objlist_Entry *elm; 2288 Obj_Entry *obj; 2289 char *saved_msg; 2290 Elf_Addr *init_addr; 2291 int index; 2292 2293 /* 2294 * Clean init_scanned flag so that objects can be rechecked and 2295 * possibly initialized earlier if any of vectors called below 2296 * cause the change by using dlopen. 2297 */ 2298 for (obj = obj_list; obj != NULL; obj = obj->next) 2299 obj->init_scanned = false; 2300 2301 /* 2302 * Preserve the current error message since an init function might 2303 * call into the dynamic linker and overwrite it. 2304 */ 2305 saved_msg = errmsg_save(); 2306 STAILQ_FOREACH(elm, list, link) { 2307 if (elm->obj->init_done) /* Initialized early. */ 2308 continue; 2309 /* 2310 * Race: other thread might try to use this object before current 2311 * one completes the initilization. Not much can be done here 2312 * without better locking. 2313 */ 2314 elm->obj->init_done = true; 2315 lock_release(rtld_bind_lock, lockstate); 2316 2317 /* 2318 * It is legal to have both DT_INIT and DT_INIT_ARRAY defined. 2319 * When this happens, DT_INIT is processed first. 2320 */ 2321 if (elm->obj->init != (Elf_Addr)NULL) { 2322 dbg("calling init function for %s at %p", elm->obj->path, 2323 (void *)elm->obj->init); 2324 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, (void *)elm->obj->init, 2325 0, 0, elm->obj->path); 2326 call_initfini_pointer(elm->obj, elm->obj->init); 2327 } 2328 init_addr = (Elf_Addr *)elm->obj->init_array; 2329 if (init_addr != NULL) { 2330 for (index = 0; index < elm->obj->init_array_num; index++) { 2331 if (init_addr[index] != 0 && init_addr[index] != 1) { 2332 dbg("calling init function for %s at %p", elm->obj->path, 2333 (void *)init_addr[index]); 2334 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, 2335 (void *)init_addr[index], 0, 0, elm->obj->path); 2336 call_init_pointer(elm->obj, init_addr[index]); 2337 } 2338 } 2339 } 2340 wlock_acquire(rtld_bind_lock, lockstate); 2341 } 2342 errmsg_restore(saved_msg); 2343} 2344 2345static void 2346objlist_clear(Objlist *list) 2347{ 2348 Objlist_Entry *elm; 2349 2350 while (!STAILQ_EMPTY(list)) { 2351 elm = STAILQ_FIRST(list); 2352 STAILQ_REMOVE_HEAD(list, link); 2353 free(elm); 2354 } 2355} 2356 2357static Objlist_Entry * 2358objlist_find(Objlist *list, const Obj_Entry *obj) 2359{ 2360 Objlist_Entry *elm; 2361 2362 STAILQ_FOREACH(elm, list, link) 2363 if (elm->obj == obj) 2364 return elm; 2365 return NULL; 2366} 2367 2368static void 2369objlist_init(Objlist *list) 2370{ 2371 STAILQ_INIT(list); 2372} 2373 2374static void 2375objlist_push_head(Objlist *list, Obj_Entry *obj) 2376{ 2377 Objlist_Entry *elm; 2378 2379 elm = NEW(Objlist_Entry); 2380 elm->obj = obj; 2381 STAILQ_INSERT_HEAD(list, elm, link); 2382} 2383 2384static void 2385objlist_push_tail(Objlist *list, Obj_Entry *obj) 2386{ 2387 Objlist_Entry *elm; 2388 2389 elm = NEW(Objlist_Entry); 2390 elm->obj = obj; 2391 STAILQ_INSERT_TAIL(list, elm, link); 2392} 2393 2394static void 2395objlist_put_after(Objlist *list, Obj_Entry *listobj, Obj_Entry *obj) 2396{ 2397 Objlist_Entry *elm, *listelm; 2398 2399 STAILQ_FOREACH(listelm, list, link) { 2400 if (listelm->obj == listobj) 2401 break; 2402 } 2403 elm = NEW(Objlist_Entry); 2404 elm->obj = obj; 2405 if (listelm != NULL) 2406 STAILQ_INSERT_AFTER(list, listelm, elm, link); 2407 else 2408 STAILQ_INSERT_TAIL(list, elm, link); 2409} 2410 2411static void 2412objlist_remove(Objlist *list, Obj_Entry *obj) 2413{ 2414 Objlist_Entry *elm; 2415 2416 if ((elm = objlist_find(list, obj)) != NULL) { 2417 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 2418 free(elm); 2419 } 2420} 2421 2422/* 2423 * Relocate dag rooted in the specified object. 2424 * Returns 0 on success, or -1 on failure. 2425 */ 2426 2427static int 2428relocate_object_dag(Obj_Entry *root, bool bind_now, Obj_Entry *rtldobj, 2429 int flags, RtldLockState *lockstate) 2430{ 2431 Objlist_Entry *elm; 2432 int error; 2433 2434 error = 0; 2435 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2436 error = relocate_object(elm->obj, bind_now, rtldobj, flags, 2437 lockstate); 2438 if (error == -1) 2439 break; 2440 } 2441 return (error); 2442} 2443 2444/* 2445 * Relocate single object. 2446 * Returns 0 on success, or -1 on failure. 2447 */ 2448static int 2449relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, 2450 int flags, RtldLockState *lockstate) 2451{ 2452 2453 if (obj->relocated) 2454 return (0); 2455 obj->relocated = true; 2456 if (obj != rtldobj) 2457 dbg("relocating \"%s\"", obj->path); 2458 2459 if (obj->symtab == NULL || obj->strtab == NULL || 2460 !(obj->valid_hash_sysv || obj->valid_hash_gnu)) { 2461 _rtld_error("%s: Shared object has no run-time symbol table", 2462 obj->path); 2463 return (-1); 2464 } 2465 2466 if (obj->textrel) { 2467 /* There are relocations to the write-protected text segment. */ 2468 if (mprotect(obj->mapbase, obj->textsize, 2469 PROT_READ|PROT_WRITE|PROT_EXEC) == -1) { 2470 _rtld_error("%s: Cannot write-enable text segment: %s", 2471 obj->path, rtld_strerror(errno)); 2472 return (-1); 2473 } 2474 } 2475 2476 /* Process the non-PLT relocations. */ 2477 if (reloc_non_plt(obj, rtldobj, flags, lockstate)) 2478 return (-1); 2479 2480 if (obj->textrel) { /* Re-protected the text segment. */ 2481 if (mprotect(obj->mapbase, obj->textsize, 2482 PROT_READ|PROT_EXEC) == -1) { 2483 _rtld_error("%s: Cannot write-protect text segment: %s", 2484 obj->path, rtld_strerror(errno)); 2485 return (-1); 2486 } 2487 } 2488 2489 2490 /* Set the special PLT or GOT entries. */ 2491 init_pltgot(obj); 2492 2493 /* Process the PLT relocations. */ 2494 if (reloc_plt(obj) == -1) 2495 return (-1); 2496 /* Relocate the jump slots if we are doing immediate binding. */ 2497 if (obj->bind_now || bind_now) 2498 if (reloc_jmpslots(obj, flags, lockstate) == -1) 2499 return (-1); 2500 2501 if (obj->relro_size > 0) { 2502 if (mprotect(obj->relro_page, obj->relro_size, 2503 PROT_READ) == -1) { 2504 _rtld_error("%s: Cannot enforce relro protection: %s", 2505 obj->path, rtld_strerror(errno)); 2506 return (-1); 2507 } 2508 } 2509 2510 /* 2511 * Set up the magic number and version in the Obj_Entry. These 2512 * were checked in the crt1.o from the original ElfKit, so we 2513 * set them for backward compatibility. 2514 */ 2515 obj->magic = RTLD_MAGIC; 2516 obj->version = RTLD_VERSION; 2517 2518 return (0); 2519} 2520 2521/* 2522 * Relocate newly-loaded shared objects. The argument is a pointer to 2523 * the Obj_Entry for the first such object. All objects from the first 2524 * to the end of the list of objects are relocated. Returns 0 on success, 2525 * or -1 on failure. 2526 */ 2527static int 2528relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj, 2529 int flags, RtldLockState *lockstate) 2530{ 2531 Obj_Entry *obj; 2532 int error; 2533 2534 for (error = 0, obj = first; obj != NULL; obj = obj->next) { 2535 error = relocate_object(obj, bind_now, rtldobj, flags, 2536 lockstate); 2537 if (error == -1) 2538 break; 2539 } 2540 return (error); 2541} 2542 2543/* 2544 * The handling of R_MACHINE_IRELATIVE relocations and jumpslots 2545 * referencing STT_GNU_IFUNC symbols is postponed till the other 2546 * relocations are done. The indirect functions specified as 2547 * ifunc are allowed to call other symbols, so we need to have 2548 * objects relocated before asking for resolution from indirects. 2549 * 2550 * The R_MACHINE_IRELATIVE slots are resolved in greedy fashion, 2551 * instead of the usual lazy handling of PLT slots. It is 2552 * consistent with how GNU does it. 2553 */ 2554static int 2555resolve_object_ifunc(Obj_Entry *obj, bool bind_now, int flags, 2556 RtldLockState *lockstate) 2557{ 2558 if (obj->irelative && reloc_iresolve(obj, lockstate) == -1) 2559 return (-1); 2560 if ((obj->bind_now || bind_now) && obj->gnu_ifunc && 2561 reloc_gnu_ifunc(obj, flags, lockstate) == -1) 2562 return (-1); 2563 return (0); 2564} 2565 2566static int 2567resolve_objects_ifunc(Obj_Entry *first, bool bind_now, int flags, 2568 RtldLockState *lockstate) 2569{ 2570 Obj_Entry *obj; 2571 2572 for (obj = first; obj != NULL; obj = obj->next) { 2573 if (resolve_object_ifunc(obj, bind_now, flags, lockstate) == -1) 2574 return (-1); 2575 } 2576 return (0); 2577} 2578 2579static int 2580initlist_objects_ifunc(Objlist *list, bool bind_now, int flags, 2581 RtldLockState *lockstate) 2582{ 2583 Objlist_Entry *elm; 2584 2585 STAILQ_FOREACH(elm, list, link) { 2586 if (resolve_object_ifunc(elm->obj, bind_now, flags, 2587 lockstate) == -1) 2588 return (-1); 2589 } 2590 return (0); 2591} 2592 2593/* 2594 * Cleanup procedure. It will be called (by the atexit mechanism) just 2595 * before the process exits. 2596 */ 2597static void 2598rtld_exit(void) 2599{ 2600 RtldLockState lockstate; 2601 2602 wlock_acquire(rtld_bind_lock, &lockstate); 2603 dbg("rtld_exit()"); 2604 objlist_call_fini(&list_fini, NULL, &lockstate); 2605 /* No need to remove the items from the list, since we are exiting. */ 2606 if (!libmap_disable) 2607 lm_fini(); 2608 lock_release(rtld_bind_lock, &lockstate); 2609} 2610 2611/* 2612 * Iterate over a search path, translate each element, and invoke the 2613 * callback on the result. 2614 */ 2615static void * 2616path_enumerate(const char *path, path_enum_proc callback, void *arg) 2617{ 2618 const char *trans; 2619 if (path == NULL) 2620 return (NULL); 2621 2622 path += strspn(path, ":;"); 2623 while (*path != '\0') { 2624 size_t len; 2625 char *res; 2626 2627 len = strcspn(path, ":;"); 2628 trans = lm_findn(NULL, path, len); 2629 if (trans) 2630 res = callback(trans, strlen(trans), arg); 2631 else 2632 res = callback(path, len, arg); 2633 2634 if (res != NULL) 2635 return (res); 2636 2637 path += len; 2638 path += strspn(path, ":;"); 2639 } 2640 2641 return (NULL); 2642} 2643 2644struct try_library_args { 2645 const char *name; 2646 size_t namelen; 2647 char *buffer; 2648 size_t buflen; 2649}; 2650 2651static void * 2652try_library_path(const char *dir, size_t dirlen, void *param) 2653{ 2654 struct try_library_args *arg; 2655 2656 arg = param; 2657 if (*dir == '/' || trust) { 2658 char *pathname; 2659 2660 if (dirlen + 1 + arg->namelen + 1 > arg->buflen) 2661 return (NULL); 2662 2663 pathname = arg->buffer; 2664 strncpy(pathname, dir, dirlen); 2665 pathname[dirlen] = '/'; 2666 strcpy(pathname + dirlen + 1, arg->name); 2667 2668 dbg(" Trying \"%s\"", pathname); 2669 if (access(pathname, F_OK) == 0) { /* We found it */ 2670 pathname = xmalloc(dirlen + 1 + arg->namelen + 1); 2671 strcpy(pathname, arg->buffer); 2672 return (pathname); 2673 } 2674 } 2675 return (NULL); 2676} 2677 2678static char * 2679search_library_path(const char *name, const char *path) 2680{ 2681 char *p; 2682 struct try_library_args arg; 2683 2684 if (path == NULL) 2685 return NULL; 2686 2687 arg.name = name; 2688 arg.namelen = strlen(name); 2689 arg.buffer = xmalloc(PATH_MAX); 2690 arg.buflen = PATH_MAX; 2691 2692 p = path_enumerate(path, try_library_path, &arg); 2693 2694 free(arg.buffer); 2695 2696 return (p); 2697} 2698 2699int 2700dlclose(void *handle) 2701{ 2702 Obj_Entry *root; 2703 RtldLockState lockstate; 2704 2705 wlock_acquire(rtld_bind_lock, &lockstate); 2706 root = dlcheck(handle); 2707 if (root == NULL) { 2708 lock_release(rtld_bind_lock, &lockstate); 2709 return -1; 2710 } 2711 LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount, 2712 root->path); 2713 2714 /* Unreference the object and its dependencies. */ 2715 root->dl_refcount--; 2716 2717 if (root->refcount == 1) { 2718 /* 2719 * The object will be no longer referenced, so we must unload it. 2720 * First, call the fini functions. 2721 */ 2722 objlist_call_fini(&list_fini, root, &lockstate); 2723 2724 unref_dag(root); 2725 2726 /* Finish cleaning up the newly-unreferenced objects. */ 2727 GDB_STATE(RT_DELETE,&root->linkmap); 2728 unload_object(root); 2729 GDB_STATE(RT_CONSISTENT,NULL); 2730 } else 2731 unref_dag(root); 2732 2733 LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL); 2734 lock_release(rtld_bind_lock, &lockstate); 2735 return 0; 2736} 2737 2738char * 2739dlerror(void) 2740{ 2741 char *msg = error_message; 2742 error_message = NULL; 2743 return msg; 2744} 2745 2746/* 2747 * This function is deprecated and has no effect. 2748 */ 2749void 2750dllockinit(void *context, 2751 void *(*lock_create)(void *context), 2752 void (*rlock_acquire)(void *lock), 2753 void (*wlock_acquire)(void *lock), 2754 void (*lock_release)(void *lock), 2755 void (*lock_destroy)(void *lock), 2756 void (*context_destroy)(void *context)) 2757{ 2758 static void *cur_context; 2759 static void (*cur_context_destroy)(void *); 2760 2761 /* Just destroy the context from the previous call, if necessary. */ 2762 if (cur_context_destroy != NULL) 2763 cur_context_destroy(cur_context); 2764 cur_context = context; 2765 cur_context_destroy = context_destroy; 2766} 2767 2768void * 2769dlopen(const char *name, int mode) 2770{ 2771 2772 return (rtld_dlopen(name, -1, mode)); 2773} 2774 2775void * 2776fdlopen(int fd, int mode) 2777{ 2778 2779 return (rtld_dlopen(NULL, fd, mode)); 2780} 2781 2782static void * 2783rtld_dlopen(const char *name, int fd, int mode) 2784{ 2785 RtldLockState lockstate; 2786 int lo_flags; 2787 2788 LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name); 2789 ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1"; 2790 if (ld_tracing != NULL) { 2791 rlock_acquire(rtld_bind_lock, &lockstate); 2792 if (sigsetjmp(lockstate.env, 0) != 0) 2793 lock_upgrade(rtld_bind_lock, &lockstate); 2794 environ = (char **)*get_program_var_addr("environ", &lockstate); 2795 lock_release(rtld_bind_lock, &lockstate); 2796 } 2797 lo_flags = RTLD_LO_DLOPEN; 2798 if (mode & RTLD_NODELETE) 2799 lo_flags |= RTLD_LO_NODELETE; 2800 if (mode & RTLD_NOLOAD) 2801 lo_flags |= RTLD_LO_NOLOAD; 2802 if (ld_tracing != NULL) 2803 lo_flags |= RTLD_LO_TRACE; 2804 2805 return (dlopen_object(name, fd, obj_main, lo_flags, 2806 mode & (RTLD_MODEMASK | RTLD_GLOBAL), NULL)); 2807} 2808 2809static void 2810dlopen_cleanup(Obj_Entry *obj) 2811{ 2812 2813 obj->dl_refcount--; 2814 unref_dag(obj); 2815 if (obj->refcount == 0) 2816 unload_object(obj); 2817} 2818 2819static Obj_Entry * 2820dlopen_object(const char *name, int fd, Obj_Entry *refobj, int lo_flags, 2821 int mode, RtldLockState *lockstate) 2822{ 2823 Obj_Entry **old_obj_tail; 2824 Obj_Entry *obj; 2825 Objlist initlist; 2826 RtldLockState mlockstate; 2827 int result; 2828 2829 objlist_init(&initlist); 2830 2831 if (lockstate == NULL && !(lo_flags & RTLD_LO_EARLY)) { 2832 wlock_acquire(rtld_bind_lock, &mlockstate); 2833 lockstate = &mlockstate; 2834 } 2835 GDB_STATE(RT_ADD,NULL); 2836 2837 old_obj_tail = obj_tail; 2838 obj = NULL; 2839 if (name == NULL && fd == -1) { 2840 obj = obj_main; 2841 obj->refcount++; 2842 } else { 2843 obj = load_object(name, fd, refobj, lo_flags); 2844 } 2845 2846 if (obj) { 2847 obj->dl_refcount++; 2848 if (mode & RTLD_GLOBAL && objlist_find(&list_global, obj) == NULL) 2849 objlist_push_tail(&list_global, obj); 2850 if (*old_obj_tail != NULL) { /* We loaded something new. */ 2851 assert(*old_obj_tail == obj); 2852 result = load_needed_objects(obj, 2853 lo_flags & (RTLD_LO_DLOPEN | RTLD_LO_EARLY)); 2854 init_dag(obj); 2855 ref_dag(obj); 2856 if (result != -1) 2857 result = rtld_verify_versions(&obj->dagmembers); 2858 if (result != -1 && ld_tracing) 2859 goto trace; 2860 if (result == -1 || relocate_object_dag(obj, 2861 (mode & RTLD_MODEMASK) == RTLD_NOW, &obj_rtld, 2862 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 2863 lockstate) == -1) { 2864 dlopen_cleanup(obj); 2865 obj = NULL; 2866 } else if (lo_flags & RTLD_LO_EARLY) { 2867 /* 2868 * Do not call the init functions for early loaded 2869 * filtees. The image is still not initialized enough 2870 * for them to work. 2871 * 2872 * Our object is found by the global object list and 2873 * will be ordered among all init calls done right 2874 * before transferring control to main. 2875 */ 2876 } else { 2877 /* Make list of init functions to call. */ 2878 initlist_add_objects(obj, &obj->next, &initlist); 2879 } 2880 /* 2881 * Process all no_delete objects here, given them own 2882 * DAGs to prevent their dependencies from being unloaded. 2883 * This has to be done after we have loaded all of the 2884 * dependencies, so that we do not miss any. 2885 */ 2886 if (obj != NULL) 2887 process_nodelete(obj); 2888 } else { 2889 /* 2890 * Bump the reference counts for objects on this DAG. If 2891 * this is the first dlopen() call for the object that was 2892 * already loaded as a dependency, initialize the dag 2893 * starting at it. 2894 */ 2895 init_dag(obj); 2896 ref_dag(obj); 2897 2898 if ((lo_flags & RTLD_LO_TRACE) != 0) 2899 goto trace; 2900 } 2901 if (obj != NULL && ((lo_flags & RTLD_LO_NODELETE) != 0 || 2902 obj->z_nodelete) && !obj->ref_nodel) { 2903 dbg("obj %s nodelete", obj->path); 2904 ref_dag(obj); 2905 obj->z_nodelete = obj->ref_nodel = true; 2906 } 2907 } 2908 2909 LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0, 2910 name); 2911 GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL); 2912 2913 if (!(lo_flags & RTLD_LO_EARLY)) { 2914 map_stacks_exec(lockstate); 2915 } 2916 2917 if (initlist_objects_ifunc(&initlist, (mode & RTLD_MODEMASK) == RTLD_NOW, 2918 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 2919 lockstate) == -1) { 2920 objlist_clear(&initlist); 2921 dlopen_cleanup(obj); 2922 if (lockstate == &mlockstate) 2923 lock_release(rtld_bind_lock, lockstate); 2924 return (NULL); 2925 } 2926 2927 if (!(lo_flags & RTLD_LO_EARLY)) { 2928 /* Call the init functions. */ 2929 objlist_call_init(&initlist, lockstate); 2930 } 2931 objlist_clear(&initlist); 2932 if (lockstate == &mlockstate) 2933 lock_release(rtld_bind_lock, lockstate); 2934 return obj; 2935trace: 2936 trace_loaded_objects(obj); 2937 if (lockstate == &mlockstate) 2938 lock_release(rtld_bind_lock, lockstate); 2939 exit(0); 2940} 2941 2942static void * 2943do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve, 2944 int flags) 2945{ 2946 DoneList donelist; 2947 const Obj_Entry *obj, *defobj; 2948 const Elf_Sym *def; 2949 SymLook req; 2950 RtldLockState lockstate; 2951#ifndef __ia64__ 2952 tls_index ti; 2953#endif 2954 int res; 2955 2956 def = NULL; 2957 defobj = NULL; 2958 symlook_init(&req, name); 2959 req.ventry = ve; 2960 req.flags = flags | SYMLOOK_IN_PLT; 2961 req.lockstate = &lockstate; 2962 2963 rlock_acquire(rtld_bind_lock, &lockstate); 2964 if (sigsetjmp(lockstate.env, 0) != 0) 2965 lock_upgrade(rtld_bind_lock, &lockstate); 2966 if (handle == NULL || handle == RTLD_NEXT || 2967 handle == RTLD_DEFAULT || handle == RTLD_SELF) { 2968 2969 if ((obj = obj_from_addr(retaddr)) == NULL) { 2970 _rtld_error("Cannot determine caller's shared object"); 2971 lock_release(rtld_bind_lock, &lockstate); 2972 return NULL; 2973 } 2974 if (handle == NULL) { /* Just the caller's shared object. */ 2975 res = symlook_obj(&req, obj); 2976 if (res == 0) { 2977 def = req.sym_out; 2978 defobj = req.defobj_out; 2979 } 2980 } else if (handle == RTLD_NEXT || /* Objects after caller's */ 2981 handle == RTLD_SELF) { /* ... caller included */ 2982 if (handle == RTLD_NEXT) 2983 obj = obj->next; 2984 for (; obj != NULL; obj = obj->next) { 2985 res = symlook_obj(&req, obj); 2986 if (res == 0) { 2987 if (def == NULL || 2988 ELF_ST_BIND(req.sym_out->st_info) != STB_WEAK) { 2989 def = req.sym_out; 2990 defobj = req.defobj_out; 2991 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 2992 break; 2993 } 2994 } 2995 } 2996 /* 2997 * Search the dynamic linker itself, and possibly resolve the 2998 * symbol from there. This is how the application links to 2999 * dynamic linker services such as dlopen. 3000 */ 3001 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 3002 res = symlook_obj(&req, &obj_rtld); 3003 if (res == 0) { 3004 def = req.sym_out; 3005 defobj = req.defobj_out; 3006 } 3007 } 3008 } else { 3009 assert(handle == RTLD_DEFAULT); 3010 res = symlook_default(&req, obj); 3011 if (res == 0) { 3012 defobj = req.defobj_out; 3013 def = req.sym_out; 3014 } 3015 } 3016 } else { 3017 if ((obj = dlcheck(handle)) == NULL) { 3018 lock_release(rtld_bind_lock, &lockstate); 3019 return NULL; 3020 } 3021 3022 donelist_init(&donelist); 3023 if (obj->mainprog) { 3024 /* Handle obtained by dlopen(NULL, ...) implies global scope. */ 3025 res = symlook_global(&req, &donelist); 3026 if (res == 0) { 3027 def = req.sym_out; 3028 defobj = req.defobj_out; 3029 } 3030 /* 3031 * Search the dynamic linker itself, and possibly resolve the 3032 * symbol from there. This is how the application links to 3033 * dynamic linker services such as dlopen. 3034 */ 3035 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 3036 res = symlook_obj(&req, &obj_rtld); 3037 if (res == 0) { 3038 def = req.sym_out; 3039 defobj = req.defobj_out; 3040 } 3041 } 3042 } 3043 else { 3044 /* Search the whole DAG rooted at the given object. */ 3045 res = symlook_list(&req, &obj->dagmembers, &donelist); 3046 if (res == 0) { 3047 def = req.sym_out; 3048 defobj = req.defobj_out; 3049 } 3050 } 3051 } 3052 3053 if (def != NULL) { 3054 lock_release(rtld_bind_lock, &lockstate); 3055 3056 /* 3057 * The value required by the caller is derived from the value 3058 * of the symbol. For the ia64 architecture, we need to 3059 * construct a function descriptor which the caller can use to 3060 * call the function with the right 'gp' value. For other 3061 * architectures and for non-functions, the value is simply 3062 * the relocated value of the symbol. 3063 */ 3064 if (ELF_ST_TYPE(def->st_info) == STT_FUNC) 3065 return (make_function_pointer(def, defobj)); 3066 else if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 3067 return (rtld_resolve_ifunc(defobj, def)); 3068 else if (ELF_ST_TYPE(def->st_info) == STT_TLS) { 3069#ifdef __ia64__ 3070 return (__tls_get_addr(defobj->tlsindex, def->st_value)); 3071#else 3072 ti.ti_module = defobj->tlsindex; 3073 ti.ti_offset = def->st_value; 3074 return (__tls_get_addr(&ti)); 3075#endif 3076 } else 3077 return (defobj->relocbase + def->st_value); 3078 } 3079 3080 _rtld_error("Undefined symbol \"%s\"", name); 3081 lock_release(rtld_bind_lock, &lockstate); 3082 return NULL; 3083} 3084 3085void * 3086dlsym(void *handle, const char *name) 3087{ 3088 return do_dlsym(handle, name, __builtin_return_address(0), NULL, 3089 SYMLOOK_DLSYM); 3090} 3091 3092dlfunc_t 3093dlfunc(void *handle, const char *name) 3094{ 3095 union { 3096 void *d; 3097 dlfunc_t f; 3098 } rv; 3099 3100 rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL, 3101 SYMLOOK_DLSYM); 3102 return (rv.f); 3103} 3104 3105void * 3106dlvsym(void *handle, const char *name, const char *version) 3107{ 3108 Ver_Entry ventry; 3109 3110 ventry.name = version; 3111 ventry.file = NULL; 3112 ventry.hash = elf_hash(version); 3113 ventry.flags= 0; 3114 return do_dlsym(handle, name, __builtin_return_address(0), &ventry, 3115 SYMLOOK_DLSYM); 3116} 3117 3118int 3119_rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info) 3120{ 3121 const Obj_Entry *obj; 3122 RtldLockState lockstate; 3123 3124 rlock_acquire(rtld_bind_lock, &lockstate); 3125 obj = obj_from_addr(addr); 3126 if (obj == NULL) { 3127 _rtld_error("No shared object contains address"); 3128 lock_release(rtld_bind_lock, &lockstate); 3129 return (0); 3130 } 3131 rtld_fill_dl_phdr_info(obj, phdr_info); 3132 lock_release(rtld_bind_lock, &lockstate); 3133 return (1); 3134} 3135 3136int 3137dladdr(const void *addr, Dl_info *info) 3138{ 3139 const Obj_Entry *obj; 3140 const Elf_Sym *def; 3141 void *symbol_addr; 3142 unsigned long symoffset; 3143 RtldLockState lockstate; 3144 3145 rlock_acquire(rtld_bind_lock, &lockstate); 3146 obj = obj_from_addr(addr); 3147 if (obj == NULL) { 3148 _rtld_error("No shared object contains address"); 3149 lock_release(rtld_bind_lock, &lockstate); 3150 return 0; 3151 } 3152 info->dli_fname = obj->path; 3153 info->dli_fbase = obj->mapbase; 3154 info->dli_saddr = (void *)0; 3155 info->dli_sname = NULL; 3156 3157 /* 3158 * Walk the symbol list looking for the symbol whose address is 3159 * closest to the address sent in. 3160 */ 3161 for (symoffset = 0; symoffset < obj->dynsymcount; symoffset++) { 3162 def = obj->symtab + symoffset; 3163 3164 /* 3165 * For skip the symbol if st_shndx is either SHN_UNDEF or 3166 * SHN_COMMON. 3167 */ 3168 if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON) 3169 continue; 3170 3171 /* 3172 * If the symbol is greater than the specified address, or if it 3173 * is further away from addr than the current nearest symbol, 3174 * then reject it. 3175 */ 3176 symbol_addr = obj->relocbase + def->st_value; 3177 if (symbol_addr > addr || symbol_addr < info->dli_saddr) 3178 continue; 3179 3180 /* Update our idea of the nearest symbol. */ 3181 info->dli_sname = obj->strtab + def->st_name; 3182 info->dli_saddr = symbol_addr; 3183 3184 /* Exact match? */ 3185 if (info->dli_saddr == addr) 3186 break; 3187 } 3188 lock_release(rtld_bind_lock, &lockstate); 3189 return 1; 3190} 3191 3192int 3193dlinfo(void *handle, int request, void *p) 3194{ 3195 const Obj_Entry *obj; 3196 RtldLockState lockstate; 3197 int error; 3198 3199 rlock_acquire(rtld_bind_lock, &lockstate); 3200 3201 if (handle == NULL || handle == RTLD_SELF) { 3202 void *retaddr; 3203 3204 retaddr = __builtin_return_address(0); /* __GNUC__ only */ 3205 if ((obj = obj_from_addr(retaddr)) == NULL) 3206 _rtld_error("Cannot determine caller's shared object"); 3207 } else 3208 obj = dlcheck(handle); 3209 3210 if (obj == NULL) { 3211 lock_release(rtld_bind_lock, &lockstate); 3212 return (-1); 3213 } 3214 3215 error = 0; 3216 switch (request) { 3217 case RTLD_DI_LINKMAP: 3218 *((struct link_map const **)p) = &obj->linkmap; 3219 break; 3220 case RTLD_DI_ORIGIN: 3221 error = rtld_dirname(obj->path, p); 3222 break; 3223 3224 case RTLD_DI_SERINFOSIZE: 3225 case RTLD_DI_SERINFO: 3226 error = do_search_info(obj, request, (struct dl_serinfo *)p); 3227 break; 3228 3229 default: 3230 _rtld_error("Invalid request %d passed to dlinfo()", request); 3231 error = -1; 3232 } 3233 3234 lock_release(rtld_bind_lock, &lockstate); 3235 3236 return (error); 3237} 3238 3239static void 3240rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info) 3241{ 3242 3243 phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase; 3244 phdr_info->dlpi_name = STAILQ_FIRST(&obj->names) ? 3245 STAILQ_FIRST(&obj->names)->name : obj->path; 3246 phdr_info->dlpi_phdr = obj->phdr; 3247 phdr_info->dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]); 3248 phdr_info->dlpi_tls_modid = obj->tlsindex; 3249 phdr_info->dlpi_tls_data = obj->tlsinit; 3250 phdr_info->dlpi_adds = obj_loads; 3251 phdr_info->dlpi_subs = obj_loads - obj_count; 3252} 3253 3254int 3255dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param) 3256{ 3257 struct dl_phdr_info phdr_info; 3258 const Obj_Entry *obj; 3259 RtldLockState bind_lockstate, phdr_lockstate; 3260 int error; 3261 3262 wlock_acquire(rtld_phdr_lock, &phdr_lockstate); 3263 rlock_acquire(rtld_bind_lock, &bind_lockstate); 3264 3265 error = 0; 3266 3267 for (obj = obj_list; obj != NULL; obj = obj->next) { 3268 rtld_fill_dl_phdr_info(obj, &phdr_info); 3269 if ((error = callback(&phdr_info, sizeof phdr_info, param)) != 0) 3270 break; 3271 3272 } 3273 lock_release(rtld_bind_lock, &bind_lockstate); 3274 lock_release(rtld_phdr_lock, &phdr_lockstate); 3275 3276 return (error); 3277} 3278 3279static void * 3280fill_search_info(const char *dir, size_t dirlen, void *param) 3281{ 3282 struct fill_search_info_args *arg; 3283 3284 arg = param; 3285 3286 if (arg->request == RTLD_DI_SERINFOSIZE) { 3287 arg->serinfo->dls_cnt ++; 3288 arg->serinfo->dls_size += sizeof(struct dl_serpath) + dirlen + 1; 3289 } else { 3290 struct dl_serpath *s_entry; 3291 3292 s_entry = arg->serpath; 3293 s_entry->dls_name = arg->strspace; 3294 s_entry->dls_flags = arg->flags; 3295 3296 strncpy(arg->strspace, dir, dirlen); 3297 arg->strspace[dirlen] = '\0'; 3298 3299 arg->strspace += dirlen + 1; 3300 arg->serpath++; 3301 } 3302 3303 return (NULL); 3304} 3305 3306static int 3307do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info) 3308{ 3309 struct dl_serinfo _info; 3310 struct fill_search_info_args args; 3311 3312 args.request = RTLD_DI_SERINFOSIZE; 3313 args.serinfo = &_info; 3314 3315 _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 3316 _info.dls_cnt = 0; 3317 3318 path_enumerate(obj->rpath, fill_search_info, &args); 3319 path_enumerate(ld_library_path, fill_search_info, &args); 3320 path_enumerate(obj->runpath, fill_search_info, &args); 3321 path_enumerate(gethints(obj->z_nodeflib), fill_search_info, &args); 3322 if (!obj->z_nodeflib) 3323 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args); 3324 3325 3326 if (request == RTLD_DI_SERINFOSIZE) { 3327 info->dls_size = _info.dls_size; 3328 info->dls_cnt = _info.dls_cnt; 3329 return (0); 3330 } 3331 3332 if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) { 3333 _rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()"); 3334 return (-1); 3335 } 3336 3337 args.request = RTLD_DI_SERINFO; 3338 args.serinfo = info; 3339 args.serpath = &info->dls_serpath[0]; 3340 args.strspace = (char *)&info->dls_serpath[_info.dls_cnt]; 3341 3342 args.flags = LA_SER_RUNPATH; 3343 if (path_enumerate(obj->rpath, fill_search_info, &args) != NULL) 3344 return (-1); 3345 3346 args.flags = LA_SER_LIBPATH; 3347 if (path_enumerate(ld_library_path, fill_search_info, &args) != NULL) 3348 return (-1); 3349 3350 args.flags = LA_SER_RUNPATH; 3351 if (path_enumerate(obj->runpath, fill_search_info, &args) != NULL) 3352 return (-1); 3353 3354 args.flags = LA_SER_CONFIG; 3355 if (path_enumerate(gethints(obj->z_nodeflib), fill_search_info, &args) 3356 != NULL) 3357 return (-1); 3358 3359 args.flags = LA_SER_DEFAULT; 3360 if (!obj->z_nodeflib && 3361 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args) != NULL) 3362 return (-1); 3363 return (0); 3364} 3365 3366static int 3367rtld_dirname(const char *path, char *bname) 3368{ 3369 const char *endp; 3370 3371 /* Empty or NULL string gets treated as "." */ 3372 if (path == NULL || *path == '\0') { 3373 bname[0] = '.'; 3374 bname[1] = '\0'; 3375 return (0); 3376 } 3377 3378 /* Strip trailing slashes */ 3379 endp = path + strlen(path) - 1; 3380 while (endp > path && *endp == '/') 3381 endp--; 3382 3383 /* Find the start of the dir */ 3384 while (endp > path && *endp != '/') 3385 endp--; 3386 3387 /* Either the dir is "/" or there are no slashes */ 3388 if (endp == path) { 3389 bname[0] = *endp == '/' ? '/' : '.'; 3390 bname[1] = '\0'; 3391 return (0); 3392 } else { 3393 do { 3394 endp--; 3395 } while (endp > path && *endp == '/'); 3396 } 3397 3398 if (endp - path + 2 > PATH_MAX) 3399 { 3400 _rtld_error("Filename is too long: %s", path); 3401 return(-1); 3402 } 3403 3404 strncpy(bname, path, endp - path + 1); 3405 bname[endp - path + 1] = '\0'; 3406 return (0); 3407} 3408 3409static int 3410rtld_dirname_abs(const char *path, char *base) 3411{ 3412 char base_rel[PATH_MAX]; 3413 3414 if (rtld_dirname(path, base) == -1) 3415 return (-1); 3416 if (base[0] == '/') 3417 return (0); 3418 if (getcwd(base_rel, sizeof(base_rel)) == NULL || 3419 strlcat(base_rel, "/", sizeof(base_rel)) >= sizeof(base_rel) || 3420 strlcat(base_rel, base, sizeof(base_rel)) >= sizeof(base_rel)) 3421 return (-1); 3422 strcpy(base, base_rel); 3423 return (0); 3424} 3425 3426static void 3427linkmap_add(Obj_Entry *obj) 3428{ 3429 struct link_map *l = &obj->linkmap; 3430 struct link_map *prev; 3431 3432 obj->linkmap.l_name = obj->path; 3433 obj->linkmap.l_addr = obj->mapbase; 3434 obj->linkmap.l_ld = obj->dynamic; 3435#ifdef __mips__ 3436 /* GDB needs load offset on MIPS to use the symbols */ 3437 obj->linkmap.l_offs = obj->relocbase; 3438#endif 3439 3440 if (r_debug.r_map == NULL) { 3441 r_debug.r_map = l; 3442 return; 3443 } 3444 3445 /* 3446 * Scan to the end of the list, but not past the entry for the 3447 * dynamic linker, which we want to keep at the very end. 3448 */ 3449 for (prev = r_debug.r_map; 3450 prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap; 3451 prev = prev->l_next) 3452 ; 3453 3454 /* Link in the new entry. */ 3455 l->l_prev = prev; 3456 l->l_next = prev->l_next; 3457 if (l->l_next != NULL) 3458 l->l_next->l_prev = l; 3459 prev->l_next = l; 3460} 3461 3462static void 3463linkmap_delete(Obj_Entry *obj) 3464{ 3465 struct link_map *l = &obj->linkmap; 3466 3467 if (l->l_prev == NULL) { 3468 if ((r_debug.r_map = l->l_next) != NULL) 3469 l->l_next->l_prev = NULL; 3470 return; 3471 } 3472 3473 if ((l->l_prev->l_next = l->l_next) != NULL) 3474 l->l_next->l_prev = l->l_prev; 3475} 3476 3477/* 3478 * Function for the debugger to set a breakpoint on to gain control. 3479 * 3480 * The two parameters allow the debugger to easily find and determine 3481 * what the runtime loader is doing and to whom it is doing it. 3482 * 3483 * When the loadhook trap is hit (r_debug_state, set at program 3484 * initialization), the arguments can be found on the stack: 3485 * 3486 * +8 struct link_map *m 3487 * +4 struct r_debug *rd 3488 * +0 RetAddr 3489 */ 3490void 3491r_debug_state(struct r_debug* rd, struct link_map *m) 3492{ 3493 /* 3494 * The following is a hack to force the compiler to emit calls to 3495 * this function, even when optimizing. If the function is empty, 3496 * the compiler is not obliged to emit any code for calls to it, 3497 * even when marked __noinline. However, gdb depends on those 3498 * calls being made. 3499 */ 3500 __asm __volatile("" : : : "memory"); 3501} 3502 3503/* 3504 * Get address of the pointer variable in the main program. 3505 * Prefer non-weak symbol over the weak one. 3506 */ 3507static const void ** 3508get_program_var_addr(const char *name, RtldLockState *lockstate) 3509{ 3510 SymLook req; 3511 DoneList donelist; 3512 3513 symlook_init(&req, name); 3514 req.lockstate = lockstate; 3515 donelist_init(&donelist); 3516 if (symlook_global(&req, &donelist) != 0) 3517 return (NULL); 3518 if (ELF_ST_TYPE(req.sym_out->st_info) == STT_FUNC) 3519 return ((const void **)make_function_pointer(req.sym_out, 3520 req.defobj_out)); 3521 else if (ELF_ST_TYPE(req.sym_out->st_info) == STT_GNU_IFUNC) 3522 return ((const void **)rtld_resolve_ifunc(req.defobj_out, req.sym_out)); 3523 else 3524 return ((const void **)(req.defobj_out->relocbase + 3525 req.sym_out->st_value)); 3526} 3527 3528/* 3529 * Set a pointer variable in the main program to the given value. This 3530 * is used to set key variables such as "environ" before any of the 3531 * init functions are called. 3532 */ 3533static void 3534set_program_var(const char *name, const void *value) 3535{ 3536 const void **addr; 3537 3538 if ((addr = get_program_var_addr(name, NULL)) != NULL) { 3539 dbg("\"%s\": *%p <-- %p", name, addr, value); 3540 *addr = value; 3541 } 3542} 3543 3544/* 3545 * Search the global objects, including dependencies and main object, 3546 * for the given symbol. 3547 */ 3548static int 3549symlook_global(SymLook *req, DoneList *donelist) 3550{ 3551 SymLook req1; 3552 const Objlist_Entry *elm; 3553 int res; 3554 3555 symlook_init_from_req(&req1, req); 3556 3557 /* Search all objects loaded at program start up. */ 3558 if (req->defobj_out == NULL || 3559 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 3560 res = symlook_list(&req1, &list_main, donelist); 3561 if (res == 0 && (req->defobj_out == NULL || 3562 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 3563 req->sym_out = req1.sym_out; 3564 req->defobj_out = req1.defobj_out; 3565 assert(req->defobj_out != NULL); 3566 } 3567 } 3568 3569 /* Search all DAGs whose roots are RTLD_GLOBAL objects. */ 3570 STAILQ_FOREACH(elm, &list_global, link) { 3571 if (req->defobj_out != NULL && 3572 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK) 3573 break; 3574 res = symlook_list(&req1, &elm->obj->dagmembers, donelist); 3575 if (res == 0 && (req->defobj_out == NULL || 3576 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 3577 req->sym_out = req1.sym_out; 3578 req->defobj_out = req1.defobj_out; 3579 assert(req->defobj_out != NULL); 3580 } 3581 } 3582 3583 return (req->sym_out != NULL ? 0 : ESRCH); 3584} 3585 3586/* 3587 * Given a symbol name in a referencing object, find the corresponding 3588 * definition of the symbol. Returns a pointer to the symbol, or NULL if 3589 * no definition was found. Returns a pointer to the Obj_Entry of the 3590 * defining object via the reference parameter DEFOBJ_OUT. 3591 */ 3592static int 3593symlook_default(SymLook *req, const Obj_Entry *refobj) 3594{ 3595 DoneList donelist; 3596 const Objlist_Entry *elm; 3597 SymLook req1; 3598 int res; 3599 3600 donelist_init(&donelist); 3601 symlook_init_from_req(&req1, req); 3602 3603 /* Look first in the referencing object if linked symbolically. */ 3604 if (refobj->symbolic && !donelist_check(&donelist, refobj)) { 3605 res = symlook_obj(&req1, refobj); 3606 if (res == 0) { 3607 req->sym_out = req1.sym_out; 3608 req->defobj_out = req1.defobj_out; 3609 assert(req->defobj_out != NULL); 3610 } 3611 } 3612 3613 symlook_global(req, &donelist); 3614 3615 /* Search all dlopened DAGs containing the referencing object. */ 3616 STAILQ_FOREACH(elm, &refobj->dldags, link) { 3617 if (req->sym_out != NULL && 3618 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK) 3619 break; 3620 res = symlook_list(&req1, &elm->obj->dagmembers, &donelist); 3621 if (res == 0 && (req->sym_out == NULL || 3622 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 3623 req->sym_out = req1.sym_out; 3624 req->defobj_out = req1.defobj_out; 3625 assert(req->defobj_out != NULL); 3626 } 3627 } 3628 3629 /* 3630 * Search the dynamic linker itself, and possibly resolve the 3631 * symbol from there. This is how the application links to 3632 * dynamic linker services such as dlopen. 3633 */ 3634 if (req->sym_out == NULL || 3635 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 3636 res = symlook_obj(&req1, &obj_rtld); 3637 if (res == 0) { 3638 req->sym_out = req1.sym_out; 3639 req->defobj_out = req1.defobj_out; 3640 assert(req->defobj_out != NULL); 3641 } 3642 } 3643 3644 return (req->sym_out != NULL ? 0 : ESRCH); 3645} 3646 3647static int 3648symlook_list(SymLook *req, const Objlist *objlist, DoneList *dlp) 3649{ 3650 const Elf_Sym *def; 3651 const Obj_Entry *defobj; 3652 const Objlist_Entry *elm; 3653 SymLook req1; 3654 int res; 3655 3656 def = NULL; 3657 defobj = NULL; 3658 STAILQ_FOREACH(elm, objlist, link) { 3659 if (donelist_check(dlp, elm->obj)) 3660 continue; 3661 symlook_init_from_req(&req1, req); 3662 if ((res = symlook_obj(&req1, elm->obj)) == 0) { 3663 if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) { 3664 def = req1.sym_out; 3665 defobj = req1.defobj_out; 3666 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 3667 break; 3668 } 3669 } 3670 } 3671 if (def != NULL) { 3672 req->sym_out = def; 3673 req->defobj_out = defobj; 3674 return (0); 3675 } 3676 return (ESRCH); 3677} 3678 3679/* 3680 * Search the chain of DAGS cointed to by the given Needed_Entry 3681 * for a symbol of the given name. Each DAG is scanned completely 3682 * before advancing to the next one. Returns a pointer to the symbol, 3683 * or NULL if no definition was found. 3684 */ 3685static int 3686symlook_needed(SymLook *req, const Needed_Entry *needed, DoneList *dlp) 3687{ 3688 const Elf_Sym *def; 3689 const Needed_Entry *n; 3690 const Obj_Entry *defobj; 3691 SymLook req1; 3692 int res; 3693 3694 def = NULL; 3695 defobj = NULL; 3696 symlook_init_from_req(&req1, req); 3697 for (n = needed; n != NULL; n = n->next) { 3698 if (n->obj == NULL || 3699 (res = symlook_list(&req1, &n->obj->dagmembers, dlp)) != 0) 3700 continue; 3701 if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) { 3702 def = req1.sym_out; 3703 defobj = req1.defobj_out; 3704 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 3705 break; 3706 } 3707 } 3708 if (def != NULL) { 3709 req->sym_out = def; 3710 req->defobj_out = defobj; 3711 return (0); 3712 } 3713 return (ESRCH); 3714} 3715 3716/* 3717 * Search the symbol table of a single shared object for a symbol of 3718 * the given name and version, if requested. Returns a pointer to the 3719 * symbol, or NULL if no definition was found. If the object is 3720 * filter, return filtered symbol from filtee. 3721 * 3722 * The symbol's hash value is passed in for efficiency reasons; that 3723 * eliminates many recomputations of the hash value. 3724 */ 3725int 3726symlook_obj(SymLook *req, const Obj_Entry *obj) 3727{ 3728 DoneList donelist; 3729 SymLook req1; 3730 int flags, res, mres; 3731 3732 /* 3733 * If there is at least one valid hash at this point, we prefer to 3734 * use the faster GNU version if available. 3735 */ 3736 if (obj->valid_hash_gnu) 3737 mres = symlook_obj1_gnu(req, obj); 3738 else if (obj->valid_hash_sysv) 3739 mres = symlook_obj1_sysv(req, obj); 3740 else 3741 return (EINVAL); 3742 3743 if (mres == 0) { 3744 if (obj->needed_filtees != NULL) { 3745 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; 3746 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 3747 donelist_init(&donelist); 3748 symlook_init_from_req(&req1, req); 3749 res = symlook_needed(&req1, obj->needed_filtees, &donelist); 3750 if (res == 0) { 3751 req->sym_out = req1.sym_out; 3752 req->defobj_out = req1.defobj_out; 3753 } 3754 return (res); 3755 } 3756 if (obj->needed_aux_filtees != NULL) { 3757 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; 3758 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 3759 donelist_init(&donelist); 3760 symlook_init_from_req(&req1, req); 3761 res = symlook_needed(&req1, obj->needed_aux_filtees, &donelist); 3762 if (res == 0) { 3763 req->sym_out = req1.sym_out; 3764 req->defobj_out = req1.defobj_out; 3765 return (res); 3766 } 3767 } 3768 } 3769 return (mres); 3770} 3771 3772/* Symbol match routine common to both hash functions */ 3773static bool 3774matched_symbol(SymLook *req, const Obj_Entry *obj, Sym_Match_Result *result, 3775 const unsigned long symnum) 3776{ 3777 Elf_Versym verndx; 3778 const Elf_Sym *symp; 3779 const char *strp; 3780 3781 symp = obj->symtab + symnum; 3782 strp = obj->strtab + symp->st_name; 3783 3784 switch (ELF_ST_TYPE(symp->st_info)) { 3785 case STT_FUNC: 3786 case STT_NOTYPE: 3787 case STT_OBJECT: 3788 case STT_COMMON: 3789 case STT_GNU_IFUNC: 3790 if (symp->st_value == 0) 3791 return (false); 3792 /* fallthrough */ 3793 case STT_TLS: 3794 if (symp->st_shndx != SHN_UNDEF) 3795 break; 3796#ifndef __mips__ 3797 else if (((req->flags & SYMLOOK_IN_PLT) == 0) && 3798 (ELF_ST_TYPE(symp->st_info) == STT_FUNC)) 3799 break; 3800 /* fallthrough */ 3801#endif 3802 default: 3803 return (false); 3804 } 3805 if (req->name[0] != strp[0] || strcmp(req->name, strp) != 0) 3806 return (false); 3807 3808 if (req->ventry == NULL) { 3809 if (obj->versyms != NULL) { 3810 verndx = VER_NDX(obj->versyms[symnum]); 3811 if (verndx > obj->vernum) { 3812 _rtld_error( 3813 "%s: symbol %s references wrong version %d", 3814 obj->path, obj->strtab + symnum, verndx); 3815 return (false); 3816 } 3817 /* 3818 * If we are not called from dlsym (i.e. this 3819 * is a normal relocation from unversioned 3820 * binary), accept the symbol immediately if 3821 * it happens to have first version after this 3822 * shared object became versioned. Otherwise, 3823 * if symbol is versioned and not hidden, 3824 * remember it. If it is the only symbol with 3825 * this name exported by the shared object, it 3826 * will be returned as a match by the calling 3827 * function. If symbol is global (verndx < 2) 3828 * accept it unconditionally. 3829 */ 3830 if ((req->flags & SYMLOOK_DLSYM) == 0 && 3831 verndx == VER_NDX_GIVEN) { 3832 result->sym_out = symp; 3833 return (true); 3834 } 3835 else if (verndx >= VER_NDX_GIVEN) { 3836 if ((obj->versyms[symnum] & VER_NDX_HIDDEN) 3837 == 0) { 3838 if (result->vsymp == NULL) 3839 result->vsymp = symp; 3840 result->vcount++; 3841 } 3842 return (false); 3843 } 3844 } 3845 result->sym_out = symp; 3846 return (true); 3847 } 3848 if (obj->versyms == NULL) { 3849 if (object_match_name(obj, req->ventry->name)) { 3850 _rtld_error("%s: object %s should provide version %s " 3851 "for symbol %s", obj_rtld.path, obj->path, 3852 req->ventry->name, obj->strtab + symnum); 3853 return (false); 3854 } 3855 } else { 3856 verndx = VER_NDX(obj->versyms[symnum]); 3857 if (verndx > obj->vernum) { 3858 _rtld_error("%s: symbol %s references wrong version %d", 3859 obj->path, obj->strtab + symnum, verndx); 3860 return (false); 3861 } 3862 if (obj->vertab[verndx].hash != req->ventry->hash || 3863 strcmp(obj->vertab[verndx].name, req->ventry->name)) { 3864 /* 3865 * Version does not match. Look if this is a 3866 * global symbol and if it is not hidden. If 3867 * global symbol (verndx < 2) is available, 3868 * use it. Do not return symbol if we are 3869 * called by dlvsym, because dlvsym looks for 3870 * a specific version and default one is not 3871 * what dlvsym wants. 3872 */ 3873 if ((req->flags & SYMLOOK_DLSYM) || 3874 (verndx >= VER_NDX_GIVEN) || 3875 (obj->versyms[symnum] & VER_NDX_HIDDEN)) 3876 return (false); 3877 } 3878 } 3879 result->sym_out = symp; 3880 return (true); 3881} 3882 3883/* 3884 * Search for symbol using SysV hash function. 3885 * obj->buckets is known not to be NULL at this point; the test for this was 3886 * performed with the obj->valid_hash_sysv assignment. 3887 */ 3888static int 3889symlook_obj1_sysv(SymLook *req, const Obj_Entry *obj) 3890{ 3891 unsigned long symnum; 3892 Sym_Match_Result matchres; 3893 3894 matchres.sym_out = NULL; 3895 matchres.vsymp = NULL; 3896 matchres.vcount = 0; 3897 3898 for (symnum = obj->buckets[req->hash % obj->nbuckets]; 3899 symnum != STN_UNDEF; symnum = obj->chains[symnum]) { 3900 if (symnum >= obj->nchains) 3901 return (ESRCH); /* Bad object */ 3902 3903 if (matched_symbol(req, obj, &matchres, symnum)) { 3904 req->sym_out = matchres.sym_out; 3905 req->defobj_out = obj; 3906 return (0); 3907 } 3908 } 3909 if (matchres.vcount == 1) { 3910 req->sym_out = matchres.vsymp; 3911 req->defobj_out = obj; 3912 return (0); 3913 } 3914 return (ESRCH); 3915} 3916 3917/* Search for symbol using GNU hash function */ 3918static int 3919symlook_obj1_gnu(SymLook *req, const Obj_Entry *obj) 3920{ 3921 Elf_Addr bloom_word; 3922 const Elf32_Word *hashval; 3923 Elf32_Word bucket; 3924 Sym_Match_Result matchres; 3925 unsigned int h1, h2; 3926 unsigned long symnum; 3927 3928 matchres.sym_out = NULL; 3929 matchres.vsymp = NULL; 3930 matchres.vcount = 0; 3931 3932 /* Pick right bitmask word from Bloom filter array */ 3933 bloom_word = obj->bloom_gnu[(req->hash_gnu / __ELF_WORD_SIZE) & 3934 obj->maskwords_bm_gnu]; 3935 3936 /* Calculate modulus word size of gnu hash and its derivative */ 3937 h1 = req->hash_gnu & (__ELF_WORD_SIZE - 1); 3938 h2 = ((req->hash_gnu >> obj->shift2_gnu) & (__ELF_WORD_SIZE - 1)); 3939 3940 /* Filter out the "definitely not in set" queries */ 3941 if (((bloom_word >> h1) & (bloom_word >> h2) & 1) == 0) 3942 return (ESRCH); 3943 3944 /* Locate hash chain and corresponding value element*/ 3945 bucket = obj->buckets_gnu[req->hash_gnu % obj->nbuckets_gnu]; 3946 if (bucket == 0) 3947 return (ESRCH); 3948 hashval = &obj->chain_zero_gnu[bucket]; 3949 do { 3950 if (((*hashval ^ req->hash_gnu) >> 1) == 0) { 3951 symnum = hashval - obj->chain_zero_gnu; 3952 if (matched_symbol(req, obj, &matchres, symnum)) { 3953 req->sym_out = matchres.sym_out; 3954 req->defobj_out = obj; 3955 return (0); 3956 } 3957 } 3958 } while ((*hashval++ & 1) == 0); 3959 if (matchres.vcount == 1) { 3960 req->sym_out = matchres.vsymp; 3961 req->defobj_out = obj; 3962 return (0); 3963 } 3964 return (ESRCH); 3965} 3966 3967static void 3968trace_loaded_objects(Obj_Entry *obj) 3969{ 3970 char *fmt1, *fmt2, *fmt, *main_local, *list_containers; 3971 int c; 3972 3973 if ((main_local = getenv(LD_ "TRACE_LOADED_OBJECTS_PROGNAME")) == NULL) 3974 main_local = ""; 3975 3976 if ((fmt1 = getenv(LD_ "TRACE_LOADED_OBJECTS_FMT1")) == NULL) 3977 fmt1 = "\t%o => %p (%x)\n"; 3978 3979 if ((fmt2 = getenv(LD_ "TRACE_LOADED_OBJECTS_FMT2")) == NULL) 3980 fmt2 = "\t%o (%x)\n"; 3981 3982 list_containers = getenv(LD_ "TRACE_LOADED_OBJECTS_ALL"); 3983 3984 for (; obj; obj = obj->next) { 3985 Needed_Entry *needed; 3986 char *name, *path; 3987 bool is_lib; 3988 3989 if (list_containers && obj->needed != NULL) 3990 rtld_printf("%s:\n", obj->path); 3991 for (needed = obj->needed; needed; needed = needed->next) { 3992 if (needed->obj != NULL) { 3993 if (needed->obj->traced && !list_containers) 3994 continue; 3995 needed->obj->traced = true; 3996 path = needed->obj->path; 3997 } else 3998 path = "not found"; 3999 4000 name = (char *)obj->strtab + needed->name; 4001 is_lib = strncmp(name, "lib", 3) == 0; /* XXX - bogus */ 4002 4003 fmt = is_lib ? fmt1 : fmt2; 4004 while ((c = *fmt++) != '\0') { 4005 switch (c) { 4006 default: 4007 rtld_putchar(c); 4008 continue; 4009 case '\\': 4010 switch (c = *fmt) { 4011 case '\0': 4012 continue; 4013 case 'n': 4014 rtld_putchar('\n'); 4015 break; 4016 case 't': 4017 rtld_putchar('\t'); 4018 break; 4019 } 4020 break; 4021 case '%': 4022 switch (c = *fmt) { 4023 case '\0': 4024 continue; 4025 case '%': 4026 default: 4027 rtld_putchar(c); 4028 break; 4029 case 'A': 4030 rtld_putstr(main_local); 4031 break; 4032 case 'a': 4033 rtld_putstr(obj_main->path); 4034 break; 4035 case 'o': 4036 rtld_putstr(name); 4037 break; 4038#if 0 4039 case 'm': 4040 rtld_printf("%d", sodp->sod_major); 4041 break; 4042 case 'n': 4043 rtld_printf("%d", sodp->sod_minor); 4044 break; 4045#endif 4046 case 'p': 4047 rtld_putstr(path); 4048 break; 4049 case 'x': 4050 rtld_printf("%p", needed->obj ? needed->obj->mapbase : 4051 0); 4052 break; 4053 } 4054 break; 4055 } 4056 ++fmt; 4057 } 4058 } 4059 } 4060} 4061 4062/* 4063 * Unload a dlopened object and its dependencies from memory and from 4064 * our data structures. It is assumed that the DAG rooted in the 4065 * object has already been unreferenced, and that the object has a 4066 * reference count of 0. 4067 */ 4068static void 4069unload_object(Obj_Entry *root) 4070{ 4071 Obj_Entry *obj; 4072 Obj_Entry **linkp; 4073 4074 assert(root->refcount == 0); 4075 4076 /* 4077 * Pass over the DAG removing unreferenced objects from 4078 * appropriate lists. 4079 */ 4080 unlink_object(root); 4081 4082 /* Unmap all objects that are no longer referenced. */ 4083 linkp = &obj_list->next; 4084 while ((obj = *linkp) != NULL) { 4085 if (obj->refcount == 0) { 4086 LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 4087 obj->path); 4088 dbg("unloading \"%s\"", obj->path); 4089 unload_filtees(root); 4090 munmap(obj->mapbase, obj->mapsize); 4091 linkmap_delete(obj); 4092 *linkp = obj->next; 4093 obj_count--; 4094 obj_free(obj); 4095 } else 4096 linkp = &obj->next; 4097 } 4098 obj_tail = linkp; 4099} 4100 4101static void 4102unlink_object(Obj_Entry *root) 4103{ 4104 Objlist_Entry *elm; 4105 4106 if (root->refcount == 0) { 4107 /* Remove the object from the RTLD_GLOBAL list. */ 4108 objlist_remove(&list_global, root); 4109 4110 /* Remove the object from all objects' DAG lists. */ 4111 STAILQ_FOREACH(elm, &root->dagmembers, link) { 4112 objlist_remove(&elm->obj->dldags, root); 4113 if (elm->obj != root) 4114 unlink_object(elm->obj); 4115 } 4116 } 4117} 4118 4119static void 4120ref_dag(Obj_Entry *root) 4121{ 4122 Objlist_Entry *elm; 4123 4124 assert(root->dag_inited); 4125 STAILQ_FOREACH(elm, &root->dagmembers, link) 4126 elm->obj->refcount++; 4127} 4128 4129static void 4130unref_dag(Obj_Entry *root) 4131{ 4132 Objlist_Entry *elm; 4133 4134 assert(root->dag_inited); 4135 STAILQ_FOREACH(elm, &root->dagmembers, link) 4136 elm->obj->refcount--; 4137} 4138 4139/* 4140 * Common code for MD __tls_get_addr(). 4141 */ 4142static void *tls_get_addr_slow(Elf_Addr **, int, size_t) __noinline; 4143static void * 4144tls_get_addr_slow(Elf_Addr **dtvp, int index, size_t offset) 4145{ 4146 Elf_Addr *newdtv, *dtv; 4147 RtldLockState lockstate; 4148 int to_copy; 4149 4150 dtv = *dtvp; 4151 /* Check dtv generation in case new modules have arrived */ 4152 if (dtv[0] != tls_dtv_generation) { 4153 wlock_acquire(rtld_bind_lock, &lockstate); 4154 newdtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4155 to_copy = dtv[1]; 4156 if (to_copy > tls_max_index) 4157 to_copy = tls_max_index; 4158 memcpy(&newdtv[2], &dtv[2], to_copy * sizeof(Elf_Addr)); 4159 newdtv[0] = tls_dtv_generation; 4160 newdtv[1] = tls_max_index; 4161 free(dtv); 4162 lock_release(rtld_bind_lock, &lockstate); 4163 dtv = *dtvp = newdtv; 4164 } 4165 4166 /* Dynamically allocate module TLS if necessary */ 4167 if (dtv[index + 1] == 0) { 4168 /* Signal safe, wlock will block out signals. */ 4169 wlock_acquire(rtld_bind_lock, &lockstate); 4170 if (!dtv[index + 1]) 4171 dtv[index + 1] = (Elf_Addr)allocate_module_tls(index); 4172 lock_release(rtld_bind_lock, &lockstate); 4173 } 4174 return ((void *)(dtv[index + 1] + offset)); 4175} 4176 4177void * 4178tls_get_addr_common(Elf_Addr **dtvp, int index, size_t offset) 4179{ 4180 Elf_Addr *dtv; 4181 4182 dtv = *dtvp; 4183 /* Check dtv generation in case new modules have arrived */ 4184 if (__predict_true(dtv[0] == tls_dtv_generation && 4185 dtv[index + 1] != 0)) 4186 return ((void *)(dtv[index + 1] + offset)); 4187 return (tls_get_addr_slow(dtvp, index, offset)); 4188} 4189 4190#if defined(__arm__) || defined(__ia64__) || defined(__mips__) || defined(__powerpc__) 4191 4192/* 4193 * Allocate Static TLS using the Variant I method. 4194 */ 4195void * 4196allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign) 4197{ 4198 Obj_Entry *obj; 4199 char *tcb; 4200 Elf_Addr **tls; 4201 Elf_Addr *dtv; 4202 Elf_Addr addr; 4203 int i; 4204 4205 if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE) 4206 return (oldtcb); 4207 4208 assert(tcbsize >= TLS_TCB_SIZE); 4209 tcb = xcalloc(1, tls_static_space - TLS_TCB_SIZE + tcbsize); 4210 tls = (Elf_Addr **)(tcb + tcbsize - TLS_TCB_SIZE); 4211 4212 if (oldtcb != NULL) { 4213 memcpy(tls, oldtcb, tls_static_space); 4214 free(oldtcb); 4215 4216 /* Adjust the DTV. */ 4217 dtv = tls[0]; 4218 for (i = 0; i < dtv[1]; i++) { 4219 if (dtv[i+2] >= (Elf_Addr)oldtcb && 4220 dtv[i+2] < (Elf_Addr)oldtcb + tls_static_space) { 4221 dtv[i+2] = dtv[i+2] - (Elf_Addr)oldtcb + (Elf_Addr)tls; 4222 } 4223 } 4224 } else { 4225 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4226 tls[0] = dtv; 4227 dtv[0] = tls_dtv_generation; 4228 dtv[1] = tls_max_index; 4229 4230 for (obj = objs; obj; obj = obj->next) { 4231 if (obj->tlsoffset > 0) { 4232 addr = (Elf_Addr)tls + obj->tlsoffset; 4233 if (obj->tlsinitsize > 0) 4234 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize); 4235 if (obj->tlssize > obj->tlsinitsize) 4236 memset((void*) (addr + obj->tlsinitsize), 0, 4237 obj->tlssize - obj->tlsinitsize); 4238 dtv[obj->tlsindex + 1] = addr; 4239 } 4240 } 4241 } 4242 4243 return (tcb); 4244} 4245 4246void 4247free_tls(void *tcb, size_t tcbsize, size_t tcbalign) 4248{ 4249 Elf_Addr *dtv; 4250 Elf_Addr tlsstart, tlsend; 4251 int dtvsize, i; 4252 4253 assert(tcbsize >= TLS_TCB_SIZE); 4254 4255 tlsstart = (Elf_Addr)tcb + tcbsize - TLS_TCB_SIZE; 4256 tlsend = tlsstart + tls_static_space; 4257 4258 dtv = *(Elf_Addr **)tlsstart; 4259 dtvsize = dtv[1]; 4260 for (i = 0; i < dtvsize; i++) { 4261 if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] >= tlsend)) { 4262 free((void*)dtv[i+2]); 4263 } 4264 } 4265 free(dtv); 4266 free(tcb); 4267} 4268 4269#endif 4270 4271#if defined(__i386__) || defined(__amd64__) || defined(__sparc64__) 4272 4273/* 4274 * Allocate Static TLS using the Variant II method. 4275 */ 4276void * 4277allocate_tls(Obj_Entry *objs, void *oldtls, size_t tcbsize, size_t tcbalign) 4278{ 4279 Obj_Entry *obj; 4280 size_t size, ralign; 4281 char *tls; 4282 Elf_Addr *dtv, *olddtv; 4283 Elf_Addr segbase, oldsegbase, addr; 4284 int i; 4285 4286 ralign = tcbalign; 4287 if (tls_static_max_align > ralign) 4288 ralign = tls_static_max_align; 4289 size = round(tls_static_space, ralign) + round(tcbsize, ralign); 4290 4291 assert(tcbsize >= 2*sizeof(Elf_Addr)); 4292 tls = malloc_aligned(size, ralign); 4293 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4294 4295 segbase = (Elf_Addr)(tls + round(tls_static_space, ralign)); 4296 ((Elf_Addr*)segbase)[0] = segbase; 4297 ((Elf_Addr*)segbase)[1] = (Elf_Addr) dtv; 4298 4299 dtv[0] = tls_dtv_generation; 4300 dtv[1] = tls_max_index; 4301 4302 if (oldtls) { 4303 /* 4304 * Copy the static TLS block over whole. 4305 */ 4306 oldsegbase = (Elf_Addr) oldtls; 4307 memcpy((void *)(segbase - tls_static_space), 4308 (const void *)(oldsegbase - tls_static_space), 4309 tls_static_space); 4310 4311 /* 4312 * If any dynamic TLS blocks have been created tls_get_addr(), 4313 * move them over. 4314 */ 4315 olddtv = ((Elf_Addr**)oldsegbase)[1]; 4316 for (i = 0; i < olddtv[1]; i++) { 4317 if (olddtv[i+2] < oldsegbase - size || olddtv[i+2] > oldsegbase) { 4318 dtv[i+2] = olddtv[i+2]; 4319 olddtv[i+2] = 0; 4320 } 4321 } 4322 4323 /* 4324 * We assume that this block was the one we created with 4325 * allocate_initial_tls(). 4326 */ 4327 free_tls(oldtls, 2*sizeof(Elf_Addr), sizeof(Elf_Addr)); 4328 } else { 4329 for (obj = objs; obj; obj = obj->next) { 4330 if (obj->tlsoffset) { 4331 addr = segbase - obj->tlsoffset; 4332 memset((void*) (addr + obj->tlsinitsize), 4333 0, obj->tlssize - obj->tlsinitsize); 4334 if (obj->tlsinit) 4335 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize); 4336 dtv[obj->tlsindex + 1] = addr; 4337 } 4338 } 4339 } 4340 4341 return (void*) segbase; 4342} 4343 4344void 4345free_tls(void *tls, size_t tcbsize, size_t tcbalign) 4346{ 4347 Elf_Addr* dtv; 4348 size_t size, ralign; 4349 int dtvsize, i; 4350 Elf_Addr tlsstart, tlsend; 4351 4352 /* 4353 * Figure out the size of the initial TLS block so that we can 4354 * find stuff which ___tls_get_addr() allocated dynamically. 4355 */ 4356 ralign = tcbalign; 4357 if (tls_static_max_align > ralign) 4358 ralign = tls_static_max_align; 4359 size = round(tls_static_space, ralign); 4360 4361 dtv = ((Elf_Addr**)tls)[1]; 4362 dtvsize = dtv[1]; 4363 tlsend = (Elf_Addr) tls; 4364 tlsstart = tlsend - size; 4365 for (i = 0; i < dtvsize; i++) { 4366 if (dtv[i + 2] != 0 && (dtv[i + 2] < tlsstart || dtv[i + 2] > tlsend)) { 4367 free_aligned((void *)dtv[i + 2]); 4368 } 4369 } 4370 4371 free_aligned((void *)tlsstart); 4372 free((void*) dtv); 4373} 4374 4375#endif 4376 4377/* 4378 * Allocate TLS block for module with given index. 4379 */ 4380void * 4381allocate_module_tls(int index) 4382{ 4383 Obj_Entry* obj; 4384 char* p; 4385 4386 for (obj = obj_list; obj; obj = obj->next) { 4387 if (obj->tlsindex == index) 4388 break; 4389 } 4390 if (!obj) { 4391 _rtld_error("Can't find module with TLS index %d", index); 4392 die(); 4393 } 4394 4395 p = malloc_aligned(obj->tlssize, obj->tlsalign); 4396 memcpy(p, obj->tlsinit, obj->tlsinitsize); 4397 memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize); 4398 4399 return p; 4400} 4401 4402bool 4403allocate_tls_offset(Obj_Entry *obj) 4404{ 4405 size_t off; 4406 4407 if (obj->tls_done) 4408 return true; 4409 4410 if (obj->tlssize == 0) { 4411 obj->tls_done = true; 4412 return true; 4413 } 4414 4415 if (obj->tlsindex == 1) 4416 off = calculate_first_tls_offset(obj->tlssize, obj->tlsalign); 4417 else 4418 off = calculate_tls_offset(tls_last_offset, tls_last_size, 4419 obj->tlssize, obj->tlsalign); 4420 4421 /* 4422 * If we have already fixed the size of the static TLS block, we 4423 * must stay within that size. When allocating the static TLS, we 4424 * leave a small amount of space spare to be used for dynamically 4425 * loading modules which use static TLS. 4426 */ 4427 if (tls_static_space != 0) { 4428 if (calculate_tls_end(off, obj->tlssize) > tls_static_space) 4429 return false; 4430 } else if (obj->tlsalign > tls_static_max_align) { 4431 tls_static_max_align = obj->tlsalign; 4432 } 4433 4434 tls_last_offset = obj->tlsoffset = off; 4435 tls_last_size = obj->tlssize; 4436 obj->tls_done = true; 4437 4438 return true; 4439} 4440 4441void 4442free_tls_offset(Obj_Entry *obj) 4443{ 4444 4445 /* 4446 * If we were the last thing to allocate out of the static TLS 4447 * block, we give our space back to the 'allocator'. This is a 4448 * simplistic workaround to allow libGL.so.1 to be loaded and 4449 * unloaded multiple times. 4450 */ 4451 if (calculate_tls_end(obj->tlsoffset, obj->tlssize) 4452 == calculate_tls_end(tls_last_offset, tls_last_size)) { 4453 tls_last_offset -= obj->tlssize; 4454 tls_last_size = 0; 4455 } 4456} 4457 4458void * 4459_rtld_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign) 4460{ 4461 void *ret; 4462 RtldLockState lockstate; 4463 4464 wlock_acquire(rtld_bind_lock, &lockstate); 4465 ret = allocate_tls(obj_list, oldtls, tcbsize, tcbalign); 4466 lock_release(rtld_bind_lock, &lockstate); 4467 return (ret); 4468} 4469 4470void 4471_rtld_free_tls(void *tcb, size_t tcbsize, size_t tcbalign) 4472{ 4473 RtldLockState lockstate; 4474 4475 wlock_acquire(rtld_bind_lock, &lockstate); 4476 free_tls(tcb, tcbsize, tcbalign); 4477 lock_release(rtld_bind_lock, &lockstate); 4478} 4479 4480static void 4481object_add_name(Obj_Entry *obj, const char *name) 4482{ 4483 Name_Entry *entry; 4484 size_t len; 4485 4486 len = strlen(name); 4487 entry = malloc(sizeof(Name_Entry) + len); 4488 4489 if (entry != NULL) { 4490 strcpy(entry->name, name); 4491 STAILQ_INSERT_TAIL(&obj->names, entry, link); 4492 } 4493} 4494 4495static int 4496object_match_name(const Obj_Entry *obj, const char *name) 4497{ 4498 Name_Entry *entry; 4499 4500 STAILQ_FOREACH(entry, &obj->names, link) { 4501 if (strcmp(name, entry->name) == 0) 4502 return (1); 4503 } 4504 return (0); 4505} 4506 4507static Obj_Entry * 4508locate_dependency(const Obj_Entry *obj, const char *name) 4509{ 4510 const Objlist_Entry *entry; 4511 const Needed_Entry *needed; 4512 4513 STAILQ_FOREACH(entry, &list_main, link) { 4514 if (object_match_name(entry->obj, name)) 4515 return entry->obj; 4516 } 4517 4518 for (needed = obj->needed; needed != NULL; needed = needed->next) { 4519 if (strcmp(obj->strtab + needed->name, name) == 0 || 4520 (needed->obj != NULL && object_match_name(needed->obj, name))) { 4521 /* 4522 * If there is DT_NEEDED for the name we are looking for, 4523 * we are all set. Note that object might not be found if 4524 * dependency was not loaded yet, so the function can 4525 * return NULL here. This is expected and handled 4526 * properly by the caller. 4527 */ 4528 return (needed->obj); 4529 } 4530 } 4531 _rtld_error("%s: Unexpected inconsistency: dependency %s not found", 4532 obj->path, name); 4533 die(); 4534} 4535 4536static int 4537check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj, 4538 const Elf_Vernaux *vna) 4539{ 4540 const Elf_Verdef *vd; 4541 const char *vername; 4542 4543 vername = refobj->strtab + vna->vna_name; 4544 vd = depobj->verdef; 4545 if (vd == NULL) { 4546 _rtld_error("%s: version %s required by %s not defined", 4547 depobj->path, vername, refobj->path); 4548 return (-1); 4549 } 4550 for (;;) { 4551 if (vd->vd_version != VER_DEF_CURRENT) { 4552 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 4553 depobj->path, vd->vd_version); 4554 return (-1); 4555 } 4556 if (vna->vna_hash == vd->vd_hash) { 4557 const Elf_Verdaux *aux = (const Elf_Verdaux *) 4558 ((char *)vd + vd->vd_aux); 4559 if (strcmp(vername, depobj->strtab + aux->vda_name) == 0) 4560 return (0); 4561 } 4562 if (vd->vd_next == 0) 4563 break; 4564 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next); 4565 } 4566 if (vna->vna_flags & VER_FLG_WEAK) 4567 return (0); 4568 _rtld_error("%s: version %s required by %s not found", 4569 depobj->path, vername, refobj->path); 4570 return (-1); 4571} 4572 4573static int 4574rtld_verify_object_versions(Obj_Entry *obj) 4575{ 4576 const Elf_Verneed *vn; 4577 const Elf_Verdef *vd; 4578 const Elf_Verdaux *vda; 4579 const Elf_Vernaux *vna; 4580 const Obj_Entry *depobj; 4581 int maxvernum, vernum; 4582 4583 if (obj->ver_checked) 4584 return (0); 4585 obj->ver_checked = true; 4586 4587 maxvernum = 0; 4588 /* 4589 * Walk over defined and required version records and figure out 4590 * max index used by any of them. Do very basic sanity checking 4591 * while there. 4592 */ 4593 vn = obj->verneed; 4594 while (vn != NULL) { 4595 if (vn->vn_version != VER_NEED_CURRENT) { 4596 _rtld_error("%s: Unsupported version %d of Elf_Verneed entry", 4597 obj->path, vn->vn_version); 4598 return (-1); 4599 } 4600 vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux); 4601 for (;;) { 4602 vernum = VER_NEED_IDX(vna->vna_other); 4603 if (vernum > maxvernum) 4604 maxvernum = vernum; 4605 if (vna->vna_next == 0) 4606 break; 4607 vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next); 4608 } 4609 if (vn->vn_next == 0) 4610 break; 4611 vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next); 4612 } 4613 4614 vd = obj->verdef; 4615 while (vd != NULL) { 4616 if (vd->vd_version != VER_DEF_CURRENT) { 4617 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 4618 obj->path, vd->vd_version); 4619 return (-1); 4620 } 4621 vernum = VER_DEF_IDX(vd->vd_ndx); 4622 if (vernum > maxvernum) 4623 maxvernum = vernum; 4624 if (vd->vd_next == 0) 4625 break; 4626 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next); 4627 } 4628 4629 if (maxvernum == 0) 4630 return (0); 4631 4632 /* 4633 * Store version information in array indexable by version index. 4634 * Verify that object version requirements are satisfied along the 4635 * way. 4636 */ 4637 obj->vernum = maxvernum + 1; 4638 obj->vertab = xcalloc(obj->vernum, sizeof(Ver_Entry)); 4639 4640 vd = obj->verdef; 4641 while (vd != NULL) { 4642 if ((vd->vd_flags & VER_FLG_BASE) == 0) { 4643 vernum = VER_DEF_IDX(vd->vd_ndx); 4644 assert(vernum <= maxvernum); 4645 vda = (const Elf_Verdaux *)((char *)vd + vd->vd_aux); 4646 obj->vertab[vernum].hash = vd->vd_hash; 4647 obj->vertab[vernum].name = obj->strtab + vda->vda_name; 4648 obj->vertab[vernum].file = NULL; 4649 obj->vertab[vernum].flags = 0; 4650 } 4651 if (vd->vd_next == 0) 4652 break; 4653 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next); 4654 } 4655 4656 vn = obj->verneed; 4657 while (vn != NULL) { 4658 depobj = locate_dependency(obj, obj->strtab + vn->vn_file); 4659 if (depobj == NULL) 4660 return (-1); 4661 vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux); 4662 for (;;) { 4663 if (check_object_provided_version(obj, depobj, vna)) 4664 return (-1); 4665 vernum = VER_NEED_IDX(vna->vna_other); 4666 assert(vernum <= maxvernum); 4667 obj->vertab[vernum].hash = vna->vna_hash; 4668 obj->vertab[vernum].name = obj->strtab + vna->vna_name; 4669 obj->vertab[vernum].file = obj->strtab + vn->vn_file; 4670 obj->vertab[vernum].flags = (vna->vna_other & VER_NEED_HIDDEN) ? 4671 VER_INFO_HIDDEN : 0; 4672 if (vna->vna_next == 0) 4673 break; 4674 vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next); 4675 } 4676 if (vn->vn_next == 0) 4677 break; 4678 vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next); 4679 } 4680 return 0; 4681} 4682 4683static int 4684rtld_verify_versions(const Objlist *objlist) 4685{ 4686 Objlist_Entry *entry; 4687 int rc; 4688 4689 rc = 0; 4690 STAILQ_FOREACH(entry, objlist, link) { 4691 /* 4692 * Skip dummy objects or objects that have their version requirements 4693 * already checked. 4694 */ 4695 if (entry->obj->strtab == NULL || entry->obj->vertab != NULL) 4696 continue; 4697 if (rtld_verify_object_versions(entry->obj) == -1) { 4698 rc = -1; 4699 if (ld_tracing == NULL) 4700 break; 4701 } 4702 } 4703 if (rc == 0 || ld_tracing != NULL) 4704 rc = rtld_verify_object_versions(&obj_rtld); 4705 return rc; 4706} 4707 4708const Ver_Entry * 4709fetch_ventry(const Obj_Entry *obj, unsigned long symnum) 4710{ 4711 Elf_Versym vernum; 4712 4713 if (obj->vertab) { 4714 vernum = VER_NDX(obj->versyms[symnum]); 4715 if (vernum >= obj->vernum) { 4716 _rtld_error("%s: symbol %s has wrong verneed value %d", 4717 obj->path, obj->strtab + symnum, vernum); 4718 } else if (obj->vertab[vernum].hash != 0) { 4719 return &obj->vertab[vernum]; 4720 } 4721 } 4722 return NULL; 4723} 4724 4725int 4726_rtld_get_stack_prot(void) 4727{ 4728 4729 return (stack_prot); 4730} 4731 4732static void 4733map_stacks_exec(RtldLockState *lockstate) 4734{ 4735 void (*thr_map_stacks_exec)(void); 4736 4737 if ((max_stack_flags & PF_X) == 0 || (stack_prot & PROT_EXEC) != 0) 4738 return; 4739 thr_map_stacks_exec = (void (*)(void))(uintptr_t) 4740 get_program_var_addr("__pthread_map_stacks_exec", lockstate); 4741 if (thr_map_stacks_exec != NULL) { 4742 stack_prot |= PROT_EXEC; 4743 thr_map_stacks_exec(); 4744 } 4745} 4746 4747void 4748symlook_init(SymLook *dst, const char *name) 4749{ 4750 4751 bzero(dst, sizeof(*dst)); 4752 dst->name = name; 4753 dst->hash = elf_hash(name); 4754 dst->hash_gnu = gnu_hash(name); 4755} 4756 4757static void 4758symlook_init_from_req(SymLook *dst, const SymLook *src) 4759{ 4760 4761 dst->name = src->name; 4762 dst->hash = src->hash; 4763 dst->hash_gnu = src->hash_gnu; 4764 dst->ventry = src->ventry; 4765 dst->flags = src->flags; 4766 dst->defobj_out = NULL; 4767 dst->sym_out = NULL; 4768 dst->lockstate = src->lockstate; 4769} 4770 4771/* 4772 * Overrides for libc_pic-provided functions. 4773 */ 4774 4775int 4776__getosreldate(void) 4777{ 4778 size_t len; 4779 int oid[2]; 4780 int error, osrel; 4781 4782 if (osreldate != 0) 4783 return (osreldate); 4784 4785 oid[0] = CTL_KERN; 4786 oid[1] = KERN_OSRELDATE; 4787 osrel = 0; 4788 len = sizeof(osrel); 4789 error = sysctl(oid, 2, &osrel, &len, NULL, 0); 4790 if (error == 0 && osrel > 0 && len == sizeof(osrel)) 4791 osreldate = osrel; 4792 return (osreldate); 4793} 4794 4795void 4796exit(int status) 4797{ 4798 4799 _exit(status); 4800} 4801 4802void (*__cleanup)(void); 4803int __isthreaded = 0; 4804int _thread_autoinit_dummy_decl = 1; 4805 4806/* 4807 * No unresolved symbols for rtld. 4808 */ 4809void 4810__pthread_cxa_finalize(struct dl_phdr_info *a) 4811{ 4812} 4813 4814void 4815__stack_chk_fail(void) 4816{ 4817 4818 _rtld_error("stack overflow detected; terminated"); 4819 die(); 4820} 4821__weak_reference(__stack_chk_fail, __stack_chk_fail_local); 4822 4823void 4824__chk_fail(void) 4825{ 4826 4827 _rtld_error("buffer overflow detected; terminated"); 4828 die(); 4829} 4830 4831const char * 4832rtld_strerror(int errnum) 4833{ 4834 4835 if (errnum < 0 || errnum >= sys_nerr) 4836 return ("Unknown error"); 4837 return (sys_errlist[errnum]); 4838} 4839