rtld.c revision 276908
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 276908 2015-01-10 09:22:17Z 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; 164void _r_debug_postinit(struct link_map *) __noinline; 165 166/* 167 * Data declarations. 168 */ 169static char *error_message; /* Message for dlerror(), or NULL */ 170struct r_debug r_debug; /* for GDB; */ 171static bool libmap_disable; /* Disable libmap */ 172static bool ld_loadfltr; /* Immediate filters processing */ 173static char *libmap_override; /* Maps to use in addition to libmap.conf */ 174static bool trust; /* False for setuid and setgid programs */ 175static bool dangerous_ld_env; /* True if environment variables have been 176 used to affect the libraries loaded */ 177static char *ld_bind_now; /* Environment variable for immediate binding */ 178static char *ld_debug; /* Environment variable for debugging */ 179static char *ld_library_path; /* Environment variable for search path */ 180static char *ld_preload; /* Environment variable for libraries to 181 load first */ 182static char *ld_elf_hints_path; /* Environment variable for alternative hints path */ 183static char *ld_tracing; /* Called from ldd to print libs */ 184static char *ld_utrace; /* Use utrace() to log events. */ 185static Obj_Entry *obj_list; /* Head of linked list of shared objects */ 186static Obj_Entry **obj_tail; /* Link field of last object in list */ 187static Obj_Entry *obj_main; /* The main program shared object */ 188static Obj_Entry obj_rtld; /* The dynamic linker shared object */ 189static unsigned int obj_count; /* Number of objects in obj_list */ 190static unsigned int obj_loads; /* Number of objects in obj_list */ 191 192static Objlist list_global = /* Objects dlopened with RTLD_GLOBAL */ 193 STAILQ_HEAD_INITIALIZER(list_global); 194static Objlist list_main = /* Objects loaded at program startup */ 195 STAILQ_HEAD_INITIALIZER(list_main); 196static Objlist list_fini = /* Objects needing fini() calls */ 197 STAILQ_HEAD_INITIALIZER(list_fini); 198 199Elf_Sym sym_zero; /* For resolving undefined weak refs. */ 200 201#define GDB_STATE(s,m) r_debug.r_state = s; r_debug_state(&r_debug,m); 202 203extern Elf_Dyn _DYNAMIC; 204#pragma weak _DYNAMIC 205#ifndef RTLD_IS_DYNAMIC 206#define RTLD_IS_DYNAMIC() (&_DYNAMIC != NULL) 207#endif 208 209int osreldate, pagesize; 210 211long __stack_chk_guard[8] = {0, 0, 0, 0, 0, 0, 0, 0}; 212 213static int stack_prot = PROT_READ | PROT_WRITE | RTLD_DEFAULT_STACK_EXEC; 214static int max_stack_flags; 215 216/* 217 * Global declarations normally provided by crt1. The dynamic linker is 218 * not built with crt1, so we have to provide them ourselves. 219 */ 220char *__progname; 221char **environ; 222 223/* 224 * Used to pass argc, argv to init functions. 225 */ 226int main_argc; 227char **main_argv; 228 229/* 230 * Globals to control TLS allocation. 231 */ 232size_t tls_last_offset; /* Static TLS offset of last module */ 233size_t tls_last_size; /* Static TLS size of last module */ 234size_t tls_static_space; /* Static TLS space allocated */ 235size_t tls_static_max_align; 236int tls_dtv_generation = 1; /* Used to detect when dtv size changes */ 237int tls_max_index = 1; /* Largest module index allocated */ 238 239bool ld_library_path_rpath = false; 240 241/* 242 * Fill in a DoneList with an allocation large enough to hold all of 243 * the currently-loaded objects. Keep this as a macro since it calls 244 * alloca and we want that to occur within the scope of the caller. 245 */ 246#define donelist_init(dlp) \ 247 ((dlp)->objs = alloca(obj_count * sizeof (dlp)->objs[0]), \ 248 assert((dlp)->objs != NULL), \ 249 (dlp)->num_alloc = obj_count, \ 250 (dlp)->num_used = 0) 251 252#define UTRACE_DLOPEN_START 1 253#define UTRACE_DLOPEN_STOP 2 254#define UTRACE_DLCLOSE_START 3 255#define UTRACE_DLCLOSE_STOP 4 256#define UTRACE_LOAD_OBJECT 5 257#define UTRACE_UNLOAD_OBJECT 6 258#define UTRACE_ADD_RUNDEP 7 259#define UTRACE_PRELOAD_FINISHED 8 260#define UTRACE_INIT_CALL 9 261#define UTRACE_FINI_CALL 10 262 263struct utrace_rtld { 264 char sig[4]; /* 'RTLD' */ 265 int event; 266 void *handle; 267 void *mapbase; /* Used for 'parent' and 'init/fini' */ 268 size_t mapsize; 269 int refcnt; /* Used for 'mode' */ 270 char name[MAXPATHLEN]; 271}; 272 273#define LD_UTRACE(e, h, mb, ms, r, n) do { \ 274 if (ld_utrace != NULL) \ 275 ld_utrace_log(e, h, mb, ms, r, n); \ 276} while (0) 277 278static void 279ld_utrace_log(int event, void *handle, void *mapbase, size_t mapsize, 280 int refcnt, const char *name) 281{ 282 struct utrace_rtld ut; 283 284 ut.sig[0] = 'R'; 285 ut.sig[1] = 'T'; 286 ut.sig[2] = 'L'; 287 ut.sig[3] = 'D'; 288 ut.event = event; 289 ut.handle = handle; 290 ut.mapbase = mapbase; 291 ut.mapsize = mapsize; 292 ut.refcnt = refcnt; 293 bzero(ut.name, sizeof(ut.name)); 294 if (name) 295 strlcpy(ut.name, name, sizeof(ut.name)); 296 utrace(&ut, sizeof(ut)); 297} 298 299/* 300 * Main entry point for dynamic linking. The first argument is the 301 * stack pointer. The stack is expected to be laid out as described 302 * in the SVR4 ABI specification, Intel 386 Processor Supplement. 303 * Specifically, the stack pointer points to a word containing 304 * ARGC. Following that in the stack is a null-terminated sequence 305 * of pointers to argument strings. Then comes a null-terminated 306 * sequence of pointers to environment strings. Finally, there is a 307 * sequence of "auxiliary vector" entries. 308 * 309 * The second argument points to a place to store the dynamic linker's 310 * exit procedure pointer and the third to a place to store the main 311 * program's object. 312 * 313 * The return value is the main program's entry point. 314 */ 315func_ptr_type 316_rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp) 317{ 318 Elf_Auxinfo *aux_info[AT_COUNT]; 319 int i; 320 int argc; 321 char **argv; 322 char **env; 323 Elf_Auxinfo *aux; 324 Elf_Auxinfo *auxp; 325 const char *argv0; 326 Objlist_Entry *entry; 327 Obj_Entry *obj; 328 Obj_Entry **preload_tail; 329 Obj_Entry *last_interposer; 330 Objlist initlist; 331 RtldLockState lockstate; 332 char *library_path_rpath; 333 int mib[2]; 334 size_t len; 335 336 /* 337 * On entry, the dynamic linker itself has not been relocated yet. 338 * Be very careful not to reference any global data until after 339 * init_rtld has returned. It is OK to reference file-scope statics 340 * and string constants, and to call static and global functions. 341 */ 342 343 /* Find the auxiliary vector on the stack. */ 344 argc = *sp++; 345 argv = (char **) sp; 346 sp += argc + 1; /* Skip over arguments and NULL terminator */ 347 env = (char **) sp; 348 while (*sp++ != 0) /* Skip over environment, and NULL terminator */ 349 ; 350 aux = (Elf_Auxinfo *) sp; 351 352 /* Digest the auxiliary vector. */ 353 for (i = 0; i < AT_COUNT; i++) 354 aux_info[i] = NULL; 355 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) { 356 if (auxp->a_type < AT_COUNT) 357 aux_info[auxp->a_type] = auxp; 358 } 359 360 /* Initialize and relocate ourselves. */ 361 assert(aux_info[AT_BASE] != NULL); 362 init_rtld((caddr_t) aux_info[AT_BASE]->a_un.a_ptr, aux_info); 363 364 __progname = obj_rtld.path; 365 argv0 = argv[0] != NULL ? argv[0] : "(null)"; 366 environ = env; 367 main_argc = argc; 368 main_argv = argv; 369 370 if (aux_info[AT_CANARY] != NULL && 371 aux_info[AT_CANARY]->a_un.a_ptr != NULL) { 372 i = aux_info[AT_CANARYLEN]->a_un.a_val; 373 if (i > sizeof(__stack_chk_guard)) 374 i = sizeof(__stack_chk_guard); 375 memcpy(__stack_chk_guard, aux_info[AT_CANARY]->a_un.a_ptr, i); 376 } else { 377 mib[0] = CTL_KERN; 378 mib[1] = KERN_ARND; 379 380 len = sizeof(__stack_chk_guard); 381 if (sysctl(mib, 2, __stack_chk_guard, &len, NULL, 0) == -1 || 382 len != sizeof(__stack_chk_guard)) { 383 /* If sysctl was unsuccessful, use the "terminator canary". */ 384 ((unsigned char *)(void *)__stack_chk_guard)[0] = 0; 385 ((unsigned char *)(void *)__stack_chk_guard)[1] = 0; 386 ((unsigned char *)(void *)__stack_chk_guard)[2] = '\n'; 387 ((unsigned char *)(void *)__stack_chk_guard)[3] = 255; 388 } 389 } 390 391 trust = !issetugid(); 392 393 ld_bind_now = getenv(LD_ "BIND_NOW"); 394 /* 395 * If the process is tainted, then we un-set the dangerous environment 396 * variables. The process will be marked as tainted until setuid(2) 397 * is called. If any child process calls setuid(2) we do not want any 398 * future processes to honor the potentially un-safe variables. 399 */ 400 if (!trust) { 401 if (unsetenv(LD_ "PRELOAD") || unsetenv(LD_ "LIBMAP") || 402 unsetenv(LD_ "LIBRARY_PATH") || unsetenv(LD_ "LIBMAP_DISABLE") || 403 unsetenv(LD_ "DEBUG") || unsetenv(LD_ "ELF_HINTS_PATH") || 404 unsetenv(LD_ "LOADFLTR") || unsetenv(LD_ "LIBRARY_PATH_RPATH")) { 405 _rtld_error("environment corrupt; aborting"); 406 die(); 407 } 408 } 409 ld_debug = getenv(LD_ "DEBUG"); 410 libmap_disable = getenv(LD_ "LIBMAP_DISABLE") != NULL; 411 libmap_override = getenv(LD_ "LIBMAP"); 412 ld_library_path = getenv(LD_ "LIBRARY_PATH"); 413 ld_preload = getenv(LD_ "PRELOAD"); 414 ld_elf_hints_path = getenv(LD_ "ELF_HINTS_PATH"); 415 ld_loadfltr = getenv(LD_ "LOADFLTR") != NULL; 416 library_path_rpath = getenv(LD_ "LIBRARY_PATH_RPATH"); 417 if (library_path_rpath != NULL) { 418 if (library_path_rpath[0] == 'y' || 419 library_path_rpath[0] == 'Y' || 420 library_path_rpath[0] == '1') 421 ld_library_path_rpath = true; 422 else 423 ld_library_path_rpath = false; 424 } 425 dangerous_ld_env = libmap_disable || (libmap_override != NULL) || 426 (ld_library_path != NULL) || (ld_preload != NULL) || 427 (ld_elf_hints_path != NULL) || ld_loadfltr; 428 ld_tracing = getenv(LD_ "TRACE_LOADED_OBJECTS"); 429 ld_utrace = getenv(LD_ "UTRACE"); 430 431 if ((ld_elf_hints_path == NULL) || strlen(ld_elf_hints_path) == 0) 432 ld_elf_hints_path = _PATH_ELF_HINTS; 433 434 if (ld_debug != NULL && *ld_debug != '\0') 435 debug = 1; 436 dbg("%s is initialized, base address = %p", __progname, 437 (caddr_t) aux_info[AT_BASE]->a_un.a_ptr); 438 dbg("RTLD dynamic = %p", obj_rtld.dynamic); 439 dbg("RTLD pltgot = %p", obj_rtld.pltgot); 440 441 dbg("initializing thread locks"); 442 lockdflt_init(); 443 444 /* 445 * Load the main program, or process its program header if it is 446 * already loaded. 447 */ 448 if (aux_info[AT_EXECFD] != NULL) { /* Load the main program. */ 449 int fd = aux_info[AT_EXECFD]->a_un.a_val; 450 dbg("loading main program"); 451 obj_main = map_object(fd, argv0, NULL); 452 close(fd); 453 if (obj_main == NULL) 454 die(); 455 max_stack_flags = obj->stack_flags; 456 } else { /* Main program already loaded. */ 457 const Elf_Phdr *phdr; 458 int phnum; 459 caddr_t entry; 460 461 dbg("processing main program's program header"); 462 assert(aux_info[AT_PHDR] != NULL); 463 phdr = (const Elf_Phdr *) aux_info[AT_PHDR]->a_un.a_ptr; 464 assert(aux_info[AT_PHNUM] != NULL); 465 phnum = aux_info[AT_PHNUM]->a_un.a_val; 466 assert(aux_info[AT_PHENT] != NULL); 467 assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr)); 468 assert(aux_info[AT_ENTRY] != NULL); 469 entry = (caddr_t) aux_info[AT_ENTRY]->a_un.a_ptr; 470 if ((obj_main = digest_phdr(phdr, phnum, entry, argv0)) == NULL) 471 die(); 472 } 473 474 if (aux_info[AT_EXECPATH] != 0) { 475 char *kexecpath; 476 char buf[MAXPATHLEN]; 477 478 kexecpath = aux_info[AT_EXECPATH]->a_un.a_ptr; 479 dbg("AT_EXECPATH %p %s", kexecpath, kexecpath); 480 if (kexecpath[0] == '/') 481 obj_main->path = kexecpath; 482 else if (getcwd(buf, sizeof(buf)) == NULL || 483 strlcat(buf, "/", sizeof(buf)) >= sizeof(buf) || 484 strlcat(buf, kexecpath, sizeof(buf)) >= sizeof(buf)) 485 obj_main->path = xstrdup(argv0); 486 else 487 obj_main->path = xstrdup(buf); 488 } else { 489 dbg("No AT_EXECPATH"); 490 obj_main->path = xstrdup(argv0); 491 } 492 dbg("obj_main path %s", obj_main->path); 493 obj_main->mainprog = true; 494 495 if (aux_info[AT_STACKPROT] != NULL && 496 aux_info[AT_STACKPROT]->a_un.a_val != 0) 497 stack_prot = aux_info[AT_STACKPROT]->a_un.a_val; 498 499 /* 500 * Get the actual dynamic linker pathname from the executable if 501 * possible. (It should always be possible.) That ensures that 502 * gdb will find the right dynamic linker even if a non-standard 503 * one is being used. 504 */ 505 if (obj_main->interp != NULL && 506 strcmp(obj_main->interp, obj_rtld.path) != 0) { 507 free(obj_rtld.path); 508 obj_rtld.path = xstrdup(obj_main->interp); 509 __progname = obj_rtld.path; 510 } 511 512 digest_dynamic(obj_main, 0); 513 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", 514 obj_main->path, obj_main->valid_hash_sysv, obj_main->valid_hash_gnu, 515 obj_main->dynsymcount); 516 517 linkmap_add(obj_main); 518 linkmap_add(&obj_rtld); 519 520 /* Link the main program into the list of objects. */ 521 *obj_tail = obj_main; 522 obj_tail = &obj_main->next; 523 obj_count++; 524 obj_loads++; 525 526 /* Initialize a fake symbol for resolving undefined weak references. */ 527 sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE); 528 sym_zero.st_shndx = SHN_UNDEF; 529 sym_zero.st_value = -(uintptr_t)obj_main->relocbase; 530 531 if (!libmap_disable) 532 libmap_disable = (bool)lm_init(libmap_override); 533 534 dbg("loading LD_PRELOAD libraries"); 535 if (load_preload_objects() == -1) 536 die(); 537 preload_tail = obj_tail; 538 539 dbg("loading needed objects"); 540 if (load_needed_objects(obj_main, 0) == -1) 541 die(); 542 543 /* Make a list of all objects loaded at startup. */ 544 last_interposer = obj_main; 545 for (obj = obj_list; obj != NULL; obj = obj->next) { 546 if (obj->z_interpose && obj != obj_main) { 547 objlist_put_after(&list_main, last_interposer, obj); 548 last_interposer = obj; 549 } else { 550 objlist_push_tail(&list_main, obj); 551 } 552 obj->refcount++; 553 } 554 555 dbg("checking for required versions"); 556 if (rtld_verify_versions(&list_main) == -1 && !ld_tracing) 557 die(); 558 559 if (ld_tracing) { /* We're done */ 560 trace_loaded_objects(obj_main); 561 exit(0); 562 } 563 564 if (getenv(LD_ "DUMP_REL_PRE") != NULL) { 565 dump_relocations(obj_main); 566 exit (0); 567 } 568 569 /* 570 * Processing tls relocations requires having the tls offsets 571 * initialized. Prepare offsets before starting initial 572 * relocation processing. 573 */ 574 dbg("initializing initial thread local storage offsets"); 575 STAILQ_FOREACH(entry, &list_main, link) { 576 /* 577 * Allocate all the initial objects out of the static TLS 578 * block even if they didn't ask for it. 579 */ 580 allocate_tls_offset(entry->obj); 581 } 582 583 if (relocate_objects(obj_main, 584 ld_bind_now != NULL && *ld_bind_now != '\0', 585 &obj_rtld, SYMLOOK_EARLY, NULL) == -1) 586 die(); 587 588 dbg("doing copy relocations"); 589 if (do_copy_relocations(obj_main) == -1) 590 die(); 591 592 if (getenv(LD_ "DUMP_REL_POST") != NULL) { 593 dump_relocations(obj_main); 594 exit (0); 595 } 596 597 /* 598 * Setup TLS for main thread. This must be done after the 599 * relocations are processed, since tls initialization section 600 * might be the subject for relocations. 601 */ 602 dbg("initializing initial thread local storage"); 603 allocate_initial_tls(obj_list); 604 605 dbg("initializing key program variables"); 606 set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : ""); 607 set_program_var("environ", env); 608 set_program_var("__elf_aux_vector", aux); 609 610 /* Make a list of init functions to call. */ 611 objlist_init(&initlist); 612 initlist_add_objects(obj_list, preload_tail, &initlist); 613 614 r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */ 615 616 map_stacks_exec(NULL); 617 618 dbg("resolving ifuncs"); 619 if (resolve_objects_ifunc(obj_main, 620 ld_bind_now != NULL && *ld_bind_now != '\0', SYMLOOK_EARLY, 621 NULL) == -1) 622 die(); 623 624 if (!obj_main->crt_no_init) { 625 /* 626 * Make sure we don't call the main program's init and fini 627 * functions for binaries linked with old crt1 which calls 628 * _init itself. 629 */ 630 obj_main->init = obj_main->fini = (Elf_Addr)NULL; 631 obj_main->preinit_array = obj_main->init_array = 632 obj_main->fini_array = (Elf_Addr)NULL; 633 } 634 635 wlock_acquire(rtld_bind_lock, &lockstate); 636 if (obj_main->crt_no_init) 637 preinit_main(); 638 objlist_call_init(&initlist, &lockstate); 639 _r_debug_postinit(&obj_main->linkmap); 640 objlist_clear(&initlist); 641 dbg("loading filtees"); 642 for (obj = obj_list->next; obj != NULL; obj = obj->next) { 643 if (ld_loadfltr || obj->z_loadfltr) 644 load_filtees(obj, 0, &lockstate); 645 } 646 lock_release(rtld_bind_lock, &lockstate); 647 648 dbg("transferring control to program entry point = %p", obj_main->entry); 649 650 /* Return the exit procedure and the program entry point. */ 651 *exit_proc = rtld_exit; 652 *objp = obj_main; 653 return (func_ptr_type) obj_main->entry; 654} 655 656void * 657rtld_resolve_ifunc(const Obj_Entry *obj, const Elf_Sym *def) 658{ 659 void *ptr; 660 Elf_Addr target; 661 662 ptr = (void *)make_function_pointer(def, obj); 663 target = ((Elf_Addr (*)(void))ptr)(); 664 return ((void *)target); 665} 666 667Elf_Addr 668_rtld_bind(Obj_Entry *obj, Elf_Size reloff) 669{ 670 const Elf_Rel *rel; 671 const Elf_Sym *def; 672 const Obj_Entry *defobj; 673 Elf_Addr *where; 674 Elf_Addr target; 675 RtldLockState lockstate; 676 677 rlock_acquire(rtld_bind_lock, &lockstate); 678 if (sigsetjmp(lockstate.env, 0) != 0) 679 lock_upgrade(rtld_bind_lock, &lockstate); 680 if (obj->pltrel) 681 rel = (const Elf_Rel *) ((caddr_t) obj->pltrel + reloff); 682 else 683 rel = (const Elf_Rel *) ((caddr_t) obj->pltrela + reloff); 684 685 where = (Elf_Addr *) (obj->relocbase + rel->r_offset); 686 def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, true, NULL, 687 &lockstate); 688 if (def == NULL) 689 die(); 690 if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 691 target = (Elf_Addr)rtld_resolve_ifunc(defobj, def); 692 else 693 target = (Elf_Addr)(defobj->relocbase + def->st_value); 694 695 dbg("\"%s\" in \"%s\" ==> %p in \"%s\"", 696 defobj->strtab + def->st_name, basename(obj->path), 697 (void *)target, basename(defobj->path)); 698 699 /* 700 * Write the new contents for the jmpslot. Note that depending on 701 * architecture, the value which we need to return back to the 702 * lazy binding trampoline may or may not be the target 703 * address. The value returned from reloc_jmpslot() is the value 704 * that the trampoline needs. 705 */ 706 target = reloc_jmpslot(where, target, defobj, obj, rel); 707 lock_release(rtld_bind_lock, &lockstate); 708 return target; 709} 710 711/* 712 * Error reporting function. Use it like printf. If formats the message 713 * into a buffer, and sets things up so that the next call to dlerror() 714 * will return the message. 715 */ 716void 717_rtld_error(const char *fmt, ...) 718{ 719 static char buf[512]; 720 va_list ap; 721 722 va_start(ap, fmt); 723 rtld_vsnprintf(buf, sizeof buf, fmt, ap); 724 error_message = buf; 725 va_end(ap); 726} 727 728/* 729 * Return a dynamically-allocated copy of the current error message, if any. 730 */ 731static char * 732errmsg_save(void) 733{ 734 return error_message == NULL ? NULL : xstrdup(error_message); 735} 736 737/* 738 * Restore the current error message from a copy which was previously saved 739 * by errmsg_save(). The copy is freed. 740 */ 741static void 742errmsg_restore(char *saved_msg) 743{ 744 if (saved_msg == NULL) 745 error_message = NULL; 746 else { 747 _rtld_error("%s", saved_msg); 748 free(saved_msg); 749 } 750} 751 752static const char * 753basename(const char *name) 754{ 755 const char *p = strrchr(name, '/'); 756 return p != NULL ? p + 1 : name; 757} 758 759static struct utsname uts; 760 761static char * 762origin_subst_one(char *real, const char *kw, const char *subst, 763 bool may_free) 764{ 765 char *p, *p1, *res, *resp; 766 int subst_len, kw_len, subst_count, old_len, new_len; 767 768 kw_len = strlen(kw); 769 770 /* 771 * First, count the number of the keyword occurences, to 772 * preallocate the final string. 773 */ 774 for (p = real, subst_count = 0;; p = p1 + kw_len, subst_count++) { 775 p1 = strstr(p, kw); 776 if (p1 == NULL) 777 break; 778 } 779 780 /* 781 * If the keyword is not found, just return. 782 */ 783 if (subst_count == 0) 784 return (may_free ? real : xstrdup(real)); 785 786 /* 787 * There is indeed something to substitute. Calculate the 788 * length of the resulting string, and allocate it. 789 */ 790 subst_len = strlen(subst); 791 old_len = strlen(real); 792 new_len = old_len + (subst_len - kw_len) * subst_count; 793 res = xmalloc(new_len + 1); 794 795 /* 796 * Now, execute the substitution loop. 797 */ 798 for (p = real, resp = res, *resp = '\0';;) { 799 p1 = strstr(p, kw); 800 if (p1 != NULL) { 801 /* Copy the prefix before keyword. */ 802 memcpy(resp, p, p1 - p); 803 resp += p1 - p; 804 /* Keyword replacement. */ 805 memcpy(resp, subst, subst_len); 806 resp += subst_len; 807 *resp = '\0'; 808 p = p1 + kw_len; 809 } else 810 break; 811 } 812 813 /* Copy to the end of string and finish. */ 814 strcat(resp, p); 815 if (may_free) 816 free(real); 817 return (res); 818} 819 820static char * 821origin_subst(char *real, const char *origin_path) 822{ 823 char *res1, *res2, *res3, *res4; 824 825 if (uts.sysname[0] == '\0') { 826 if (uname(&uts) != 0) { 827 _rtld_error("utsname failed: %d", errno); 828 return (NULL); 829 } 830 } 831 res1 = origin_subst_one(real, "$ORIGIN", origin_path, false); 832 res2 = origin_subst_one(res1, "$OSNAME", uts.sysname, true); 833 res3 = origin_subst_one(res2, "$OSREL", uts.release, true); 834 res4 = origin_subst_one(res3, "$PLATFORM", uts.machine, true); 835 return (res4); 836} 837 838static void 839die(void) 840{ 841 const char *msg = dlerror(); 842 843 if (msg == NULL) 844 msg = "Fatal error"; 845 rtld_fdputstr(STDERR_FILENO, msg); 846 rtld_fdputchar(STDERR_FILENO, '\n'); 847 _exit(1); 848} 849 850/* 851 * Process a shared object's DYNAMIC section, and save the important 852 * information in its Obj_Entry structure. 853 */ 854static void 855digest_dynamic1(Obj_Entry *obj, int early, const Elf_Dyn **dyn_rpath, 856 const Elf_Dyn **dyn_soname, const Elf_Dyn **dyn_runpath) 857{ 858 const Elf_Dyn *dynp; 859 Needed_Entry **needed_tail = &obj->needed; 860 Needed_Entry **needed_filtees_tail = &obj->needed_filtees; 861 Needed_Entry **needed_aux_filtees_tail = &obj->needed_aux_filtees; 862 const Elf_Hashelt *hashtab; 863 const Elf32_Word *hashval; 864 Elf32_Word bkt, nmaskwords; 865 int bloom_size32; 866 bool nmw_power2; 867 int plttype = DT_REL; 868 869 *dyn_rpath = NULL; 870 *dyn_soname = NULL; 871 *dyn_runpath = NULL; 872 873 obj->bind_now = false; 874 for (dynp = obj->dynamic; dynp->d_tag != DT_NULL; dynp++) { 875 switch (dynp->d_tag) { 876 877 case DT_REL: 878 obj->rel = (const Elf_Rel *) (obj->relocbase + dynp->d_un.d_ptr); 879 break; 880 881 case DT_RELSZ: 882 obj->relsize = dynp->d_un.d_val; 883 break; 884 885 case DT_RELENT: 886 assert(dynp->d_un.d_val == sizeof(Elf_Rel)); 887 break; 888 889 case DT_JMPREL: 890 obj->pltrel = (const Elf_Rel *) 891 (obj->relocbase + dynp->d_un.d_ptr); 892 break; 893 894 case DT_PLTRELSZ: 895 obj->pltrelsize = dynp->d_un.d_val; 896 break; 897 898 case DT_RELA: 899 obj->rela = (const Elf_Rela *) (obj->relocbase + dynp->d_un.d_ptr); 900 break; 901 902 case DT_RELASZ: 903 obj->relasize = dynp->d_un.d_val; 904 break; 905 906 case DT_RELAENT: 907 assert(dynp->d_un.d_val == sizeof(Elf_Rela)); 908 break; 909 910 case DT_PLTREL: 911 plttype = dynp->d_un.d_val; 912 assert(dynp->d_un.d_val == DT_REL || plttype == DT_RELA); 913 break; 914 915 case DT_SYMTAB: 916 obj->symtab = (const Elf_Sym *) 917 (obj->relocbase + dynp->d_un.d_ptr); 918 break; 919 920 case DT_SYMENT: 921 assert(dynp->d_un.d_val == sizeof(Elf_Sym)); 922 break; 923 924 case DT_STRTAB: 925 obj->strtab = (const char *) (obj->relocbase + dynp->d_un.d_ptr); 926 break; 927 928 case DT_STRSZ: 929 obj->strsize = dynp->d_un.d_val; 930 break; 931 932 case DT_VERNEED: 933 obj->verneed = (const Elf_Verneed *) (obj->relocbase + 934 dynp->d_un.d_val); 935 break; 936 937 case DT_VERNEEDNUM: 938 obj->verneednum = dynp->d_un.d_val; 939 break; 940 941 case DT_VERDEF: 942 obj->verdef = (const Elf_Verdef *) (obj->relocbase + 943 dynp->d_un.d_val); 944 break; 945 946 case DT_VERDEFNUM: 947 obj->verdefnum = dynp->d_un.d_val; 948 break; 949 950 case DT_VERSYM: 951 obj->versyms = (const Elf_Versym *)(obj->relocbase + 952 dynp->d_un.d_val); 953 break; 954 955 case DT_HASH: 956 { 957 hashtab = (const Elf_Hashelt *)(obj->relocbase + 958 dynp->d_un.d_ptr); 959 obj->nbuckets = hashtab[0]; 960 obj->nchains = hashtab[1]; 961 obj->buckets = hashtab + 2; 962 obj->chains = obj->buckets + obj->nbuckets; 963 obj->valid_hash_sysv = obj->nbuckets > 0 && obj->nchains > 0 && 964 obj->buckets != NULL; 965 } 966 break; 967 968 case DT_GNU_HASH: 969 { 970 hashtab = (const Elf_Hashelt *)(obj->relocbase + 971 dynp->d_un.d_ptr); 972 obj->nbuckets_gnu = hashtab[0]; 973 obj->symndx_gnu = hashtab[1]; 974 nmaskwords = hashtab[2]; 975 bloom_size32 = (__ELF_WORD_SIZE / 32) * nmaskwords; 976 /* Number of bitmask words is required to be power of 2 */ 977 nmw_power2 = ((nmaskwords & (nmaskwords - 1)) == 0); 978 obj->maskwords_bm_gnu = nmaskwords - 1; 979 obj->shift2_gnu = hashtab[3]; 980 obj->bloom_gnu = (Elf_Addr *) (hashtab + 4); 981 obj->buckets_gnu = hashtab + 4 + bloom_size32; 982 obj->chain_zero_gnu = obj->buckets_gnu + obj->nbuckets_gnu - 983 obj->symndx_gnu; 984 obj->valid_hash_gnu = nmw_power2 && obj->nbuckets_gnu > 0 && 985 obj->buckets_gnu != NULL; 986 } 987 break; 988 989 case DT_NEEDED: 990 if (!obj->rtld) { 991 Needed_Entry *nep = NEW(Needed_Entry); 992 nep->name = dynp->d_un.d_val; 993 nep->obj = NULL; 994 nep->next = NULL; 995 996 *needed_tail = nep; 997 needed_tail = &nep->next; 998 } 999 break; 1000 1001 case DT_FILTER: 1002 if (!obj->rtld) { 1003 Needed_Entry *nep = NEW(Needed_Entry); 1004 nep->name = dynp->d_un.d_val; 1005 nep->obj = NULL; 1006 nep->next = NULL; 1007 1008 *needed_filtees_tail = nep; 1009 needed_filtees_tail = &nep->next; 1010 } 1011 break; 1012 1013 case DT_AUXILIARY: 1014 if (!obj->rtld) { 1015 Needed_Entry *nep = NEW(Needed_Entry); 1016 nep->name = dynp->d_un.d_val; 1017 nep->obj = NULL; 1018 nep->next = NULL; 1019 1020 *needed_aux_filtees_tail = nep; 1021 needed_aux_filtees_tail = &nep->next; 1022 } 1023 break; 1024 1025 case DT_PLTGOT: 1026 obj->pltgot = (Elf_Addr *) (obj->relocbase + dynp->d_un.d_ptr); 1027 break; 1028 1029 case DT_TEXTREL: 1030 obj->textrel = true; 1031 break; 1032 1033 case DT_SYMBOLIC: 1034 obj->symbolic = true; 1035 break; 1036 1037 case DT_RPATH: 1038 /* 1039 * We have to wait until later to process this, because we 1040 * might not have gotten the address of the string table yet. 1041 */ 1042 *dyn_rpath = dynp; 1043 break; 1044 1045 case DT_SONAME: 1046 *dyn_soname = dynp; 1047 break; 1048 1049 case DT_RUNPATH: 1050 *dyn_runpath = dynp; 1051 break; 1052 1053 case DT_INIT: 1054 obj->init = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr); 1055 break; 1056 1057 case DT_PREINIT_ARRAY: 1058 obj->preinit_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1059 break; 1060 1061 case DT_PREINIT_ARRAYSZ: 1062 obj->preinit_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1063 break; 1064 1065 case DT_INIT_ARRAY: 1066 obj->init_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1067 break; 1068 1069 case DT_INIT_ARRAYSZ: 1070 obj->init_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1071 break; 1072 1073 case DT_FINI: 1074 obj->fini = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr); 1075 break; 1076 1077 case DT_FINI_ARRAY: 1078 obj->fini_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1079 break; 1080 1081 case DT_FINI_ARRAYSZ: 1082 obj->fini_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1083 break; 1084 1085 /* 1086 * Don't process DT_DEBUG on MIPS as the dynamic section 1087 * is mapped read-only. DT_MIPS_RLD_MAP is used instead. 1088 */ 1089 1090#ifndef __mips__ 1091 case DT_DEBUG: 1092 /* XXX - not implemented yet */ 1093 if (!early) 1094 dbg("Filling in DT_DEBUG entry"); 1095 ((Elf_Dyn*)dynp)->d_un.d_ptr = (Elf_Addr) &r_debug; 1096 break; 1097#endif 1098 1099 case DT_FLAGS: 1100 if ((dynp->d_un.d_val & DF_ORIGIN) && trust) 1101 obj->z_origin = true; 1102 if (dynp->d_un.d_val & DF_SYMBOLIC) 1103 obj->symbolic = true; 1104 if (dynp->d_un.d_val & DF_TEXTREL) 1105 obj->textrel = true; 1106 if (dynp->d_un.d_val & DF_BIND_NOW) 1107 obj->bind_now = true; 1108 /*if (dynp->d_un.d_val & DF_STATIC_TLS) 1109 ;*/ 1110 break; 1111#ifdef __mips__ 1112 case DT_MIPS_LOCAL_GOTNO: 1113 obj->local_gotno = dynp->d_un.d_val; 1114 break; 1115 1116 case DT_MIPS_SYMTABNO: 1117 obj->symtabno = dynp->d_un.d_val; 1118 break; 1119 1120 case DT_MIPS_GOTSYM: 1121 obj->gotsym = dynp->d_un.d_val; 1122 break; 1123 1124 case DT_MIPS_RLD_MAP: 1125 *((Elf_Addr *)(dynp->d_un.d_ptr)) = (Elf_Addr) &r_debug; 1126 break; 1127#endif 1128 1129 case DT_FLAGS_1: 1130 if (dynp->d_un.d_val & DF_1_NOOPEN) 1131 obj->z_noopen = true; 1132 if ((dynp->d_un.d_val & DF_1_ORIGIN) && trust) 1133 obj->z_origin = true; 1134 /*if (dynp->d_un.d_val & DF_1_GLOBAL) 1135 XXX ;*/ 1136 if (dynp->d_un.d_val & DF_1_BIND_NOW) 1137 obj->bind_now = true; 1138 if (dynp->d_un.d_val & DF_1_NODELETE) 1139 obj->z_nodelete = true; 1140 if (dynp->d_un.d_val & DF_1_LOADFLTR) 1141 obj->z_loadfltr = true; 1142 if (dynp->d_un.d_val & DF_1_INTERPOSE) 1143 obj->z_interpose = true; 1144 if (dynp->d_un.d_val & DF_1_NODEFLIB) 1145 obj->z_nodeflib = true; 1146 break; 1147 1148 default: 1149 if (!early) { 1150 dbg("Ignoring d_tag %ld = %#lx", (long)dynp->d_tag, 1151 (long)dynp->d_tag); 1152 } 1153 break; 1154 } 1155 } 1156 1157 obj->traced = false; 1158 1159 if (plttype == DT_RELA) { 1160 obj->pltrela = (const Elf_Rela *) obj->pltrel; 1161 obj->pltrel = NULL; 1162 obj->pltrelasize = obj->pltrelsize; 1163 obj->pltrelsize = 0; 1164 } 1165 1166 /* Determine size of dynsym table (equal to nchains of sysv hash) */ 1167 if (obj->valid_hash_sysv) 1168 obj->dynsymcount = obj->nchains; 1169 else if (obj->valid_hash_gnu) { 1170 obj->dynsymcount = 0; 1171 for (bkt = 0; bkt < obj->nbuckets_gnu; bkt++) { 1172 if (obj->buckets_gnu[bkt] == 0) 1173 continue; 1174 hashval = &obj->chain_zero_gnu[obj->buckets_gnu[bkt]]; 1175 do 1176 obj->dynsymcount++; 1177 while ((*hashval++ & 1u) == 0); 1178 } 1179 obj->dynsymcount += obj->symndx_gnu; 1180 } 1181} 1182 1183static void 1184digest_dynamic2(Obj_Entry *obj, const Elf_Dyn *dyn_rpath, 1185 const Elf_Dyn *dyn_soname, const Elf_Dyn *dyn_runpath) 1186{ 1187 1188 if (obj->z_origin && obj->origin_path == NULL) { 1189 obj->origin_path = xmalloc(PATH_MAX); 1190 if (rtld_dirname_abs(obj->path, obj->origin_path) == -1) 1191 die(); 1192 } 1193 1194 if (dyn_runpath != NULL) { 1195 obj->runpath = (char *)obj->strtab + dyn_runpath->d_un.d_val; 1196 if (obj->z_origin) 1197 obj->runpath = origin_subst(obj->runpath, obj->origin_path); 1198 } 1199 else if (dyn_rpath != NULL) { 1200 obj->rpath = (char *)obj->strtab + dyn_rpath->d_un.d_val; 1201 if (obj->z_origin) 1202 obj->rpath = origin_subst(obj->rpath, obj->origin_path); 1203 } 1204 1205 if (dyn_soname != NULL) 1206 object_add_name(obj, obj->strtab + dyn_soname->d_un.d_val); 1207} 1208 1209static void 1210digest_dynamic(Obj_Entry *obj, int early) 1211{ 1212 const Elf_Dyn *dyn_rpath; 1213 const Elf_Dyn *dyn_soname; 1214 const Elf_Dyn *dyn_runpath; 1215 1216 digest_dynamic1(obj, early, &dyn_rpath, &dyn_soname, &dyn_runpath); 1217 digest_dynamic2(obj, dyn_rpath, dyn_soname, dyn_runpath); 1218} 1219 1220/* 1221 * Process a shared object's program header. This is used only for the 1222 * main program, when the kernel has already loaded the main program 1223 * into memory before calling the dynamic linker. It creates and 1224 * returns an Obj_Entry structure. 1225 */ 1226static Obj_Entry * 1227digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path) 1228{ 1229 Obj_Entry *obj; 1230 const Elf_Phdr *phlimit = phdr + phnum; 1231 const Elf_Phdr *ph; 1232 Elf_Addr note_start, note_end; 1233 int nsegs = 0; 1234 1235 obj = obj_new(); 1236 for (ph = phdr; ph < phlimit; ph++) { 1237 if (ph->p_type != PT_PHDR) 1238 continue; 1239 1240 obj->phdr = phdr; 1241 obj->phsize = ph->p_memsz; 1242 obj->relocbase = (caddr_t)phdr - ph->p_vaddr; 1243 break; 1244 } 1245 1246 obj->stack_flags = PF_X | PF_R | PF_W; 1247 1248 for (ph = phdr; ph < phlimit; ph++) { 1249 switch (ph->p_type) { 1250 1251 case PT_INTERP: 1252 obj->interp = (const char *)(ph->p_vaddr + obj->relocbase); 1253 break; 1254 1255 case PT_LOAD: 1256 if (nsegs == 0) { /* First load segment */ 1257 obj->vaddrbase = trunc_page(ph->p_vaddr); 1258 obj->mapbase = obj->vaddrbase + obj->relocbase; 1259 obj->textsize = round_page(ph->p_vaddr + ph->p_memsz) - 1260 obj->vaddrbase; 1261 } else { /* Last load segment */ 1262 obj->mapsize = round_page(ph->p_vaddr + ph->p_memsz) - 1263 obj->vaddrbase; 1264 } 1265 nsegs++; 1266 break; 1267 1268 case PT_DYNAMIC: 1269 obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + obj->relocbase); 1270 break; 1271 1272 case PT_TLS: 1273 obj->tlsindex = 1; 1274 obj->tlssize = ph->p_memsz; 1275 obj->tlsalign = ph->p_align; 1276 obj->tlsinitsize = ph->p_filesz; 1277 obj->tlsinit = (void*)(ph->p_vaddr + obj->relocbase); 1278 break; 1279 1280 case PT_GNU_STACK: 1281 obj->stack_flags = ph->p_flags; 1282 break; 1283 1284 case PT_GNU_RELRO: 1285 obj->relro_page = obj->relocbase + trunc_page(ph->p_vaddr); 1286 obj->relro_size = round_page(ph->p_memsz); 1287 break; 1288 1289 case PT_NOTE: 1290 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; 1291 note_end = note_start + ph->p_filesz; 1292 digest_notes(obj, note_start, note_end); 1293 break; 1294 } 1295 } 1296 if (nsegs < 1) { 1297 _rtld_error("%s: too few PT_LOAD segments", path); 1298 return NULL; 1299 } 1300 1301 obj->entry = entry; 1302 return obj; 1303} 1304 1305void 1306digest_notes(Obj_Entry *obj, Elf_Addr note_start, Elf_Addr note_end) 1307{ 1308 const Elf_Note *note; 1309 const char *note_name; 1310 uintptr_t p; 1311 1312 for (note = (const Elf_Note *)note_start; (Elf_Addr)note < note_end; 1313 note = (const Elf_Note *)((const char *)(note + 1) + 1314 roundup2(note->n_namesz, sizeof(Elf32_Addr)) + 1315 roundup2(note->n_descsz, sizeof(Elf32_Addr)))) { 1316 if (note->n_namesz != sizeof(NOTE_FREEBSD_VENDOR) || 1317 note->n_descsz != sizeof(int32_t)) 1318 continue; 1319 if (note->n_type != ABI_NOTETYPE && 1320 note->n_type != CRT_NOINIT_NOTETYPE) 1321 continue; 1322 note_name = (const char *)(note + 1); 1323 if (strncmp(NOTE_FREEBSD_VENDOR, note_name, 1324 sizeof(NOTE_FREEBSD_VENDOR)) != 0) 1325 continue; 1326 switch (note->n_type) { 1327 case ABI_NOTETYPE: 1328 /* FreeBSD osrel note */ 1329 p = (uintptr_t)(note + 1); 1330 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1331 obj->osrel = *(const int32_t *)(p); 1332 dbg("note osrel %d", obj->osrel); 1333 break; 1334 case CRT_NOINIT_NOTETYPE: 1335 /* FreeBSD 'crt does not call init' note */ 1336 obj->crt_no_init = true; 1337 dbg("note crt_no_init"); 1338 break; 1339 } 1340 } 1341} 1342 1343static Obj_Entry * 1344dlcheck(void *handle) 1345{ 1346 Obj_Entry *obj; 1347 1348 for (obj = obj_list; obj != NULL; obj = obj->next) 1349 if (obj == (Obj_Entry *) handle) 1350 break; 1351 1352 if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) { 1353 _rtld_error("Invalid shared object handle %p", handle); 1354 return NULL; 1355 } 1356 return obj; 1357} 1358 1359/* 1360 * If the given object is already in the donelist, return true. Otherwise 1361 * add the object to the list and return false. 1362 */ 1363static bool 1364donelist_check(DoneList *dlp, const Obj_Entry *obj) 1365{ 1366 unsigned int i; 1367 1368 for (i = 0; i < dlp->num_used; i++) 1369 if (dlp->objs[i] == obj) 1370 return true; 1371 /* 1372 * Our donelist allocation should always be sufficient. But if 1373 * our threads locking isn't working properly, more shared objects 1374 * could have been loaded since we allocated the list. That should 1375 * never happen, but we'll handle it properly just in case it does. 1376 */ 1377 if (dlp->num_used < dlp->num_alloc) 1378 dlp->objs[dlp->num_used++] = obj; 1379 return false; 1380} 1381 1382/* 1383 * Hash function for symbol table lookup. Don't even think about changing 1384 * this. It is specified by the System V ABI. 1385 */ 1386unsigned long 1387elf_hash(const char *name) 1388{ 1389 const unsigned char *p = (const unsigned char *) name; 1390 unsigned long h = 0; 1391 unsigned long g; 1392 1393 while (*p != '\0') { 1394 h = (h << 4) + *p++; 1395 if ((g = h & 0xf0000000) != 0) 1396 h ^= g >> 24; 1397 h &= ~g; 1398 } 1399 return h; 1400} 1401 1402/* 1403 * The GNU hash function is the Daniel J. Bernstein hash clipped to 32 bits 1404 * unsigned in case it's implemented with a wider type. 1405 */ 1406static uint32_t 1407gnu_hash(const char *s) 1408{ 1409 uint32_t h; 1410 unsigned char c; 1411 1412 h = 5381; 1413 for (c = *s; c != '\0'; c = *++s) 1414 h = h * 33 + c; 1415 return (h & 0xffffffff); 1416} 1417 1418/* 1419 * Find the library with the given name, and return its full pathname. 1420 * The returned string is dynamically allocated. Generates an error 1421 * message and returns NULL if the library cannot be found. 1422 * 1423 * If the second argument is non-NULL, then it refers to an already- 1424 * loaded shared object, whose library search path will be searched. 1425 * 1426 * The search order is: 1427 * DT_RPATH in the referencing file _unless_ DT_RUNPATH is present (1) 1428 * DT_RPATH of the main object if DSO without defined DT_RUNPATH (1) 1429 * LD_LIBRARY_PATH 1430 * DT_RUNPATH in the referencing file 1431 * ldconfig hints (if -z nodefaultlib, filter out default library directories 1432 * from list) 1433 * /lib:/usr/lib _unless_ the referencing file is linked with -z nodefaultlib 1434 * 1435 * (1) Handled in digest_dynamic2 - rpath left NULL if runpath defined. 1436 */ 1437static char * 1438find_library(const char *xname, const Obj_Entry *refobj) 1439{ 1440 char *pathname; 1441 char *name; 1442 bool nodeflib, objgiven; 1443 1444 objgiven = refobj != NULL; 1445 if (strchr(xname, '/') != NULL) { /* Hard coded pathname */ 1446 if (xname[0] != '/' && !trust) { 1447 _rtld_error("Absolute pathname required for shared object \"%s\"", 1448 xname); 1449 return NULL; 1450 } 1451 if (objgiven && refobj->z_origin) { 1452 return (origin_subst(__DECONST(char *, xname), 1453 refobj->origin_path)); 1454 } else { 1455 return (xstrdup(xname)); 1456 } 1457 } 1458 1459 if (libmap_disable || !objgiven || 1460 (name = lm_find(refobj->path, xname)) == NULL) 1461 name = (char *)xname; 1462 1463 dbg(" Searching for \"%s\"", name); 1464 1465 /* 1466 * If refobj->rpath != NULL, then refobj->runpath is NULL. Fall 1467 * back to pre-conforming behaviour if user requested so with 1468 * LD_LIBRARY_PATH_RPATH environment variable and ignore -z 1469 * nodeflib. 1470 */ 1471 if (objgiven && refobj->rpath != NULL && ld_library_path_rpath) { 1472 if ((pathname = search_library_path(name, ld_library_path)) != NULL || 1473 (refobj != NULL && 1474 (pathname = search_library_path(name, refobj->rpath)) != NULL) || 1475 (pathname = search_library_path(name, gethints(false))) != NULL || 1476 (pathname = search_library_path(name, STANDARD_LIBRARY_PATH)) != NULL) 1477 return (pathname); 1478 } else { 1479 nodeflib = objgiven ? refobj->z_nodeflib : false; 1480 if ((objgiven && 1481 (pathname = search_library_path(name, refobj->rpath)) != NULL) || 1482 (objgiven && refobj->runpath == NULL && refobj != obj_main && 1483 (pathname = search_library_path(name, obj_main->rpath)) != NULL) || 1484 (pathname = search_library_path(name, ld_library_path)) != NULL || 1485 (objgiven && 1486 (pathname = search_library_path(name, refobj->runpath)) != NULL) || 1487 (pathname = search_library_path(name, gethints(nodeflib))) != NULL || 1488 (objgiven && !nodeflib && 1489 (pathname = search_library_path(name, STANDARD_LIBRARY_PATH)) != NULL)) 1490 return (pathname); 1491 } 1492 1493 if (objgiven && refobj->path != NULL) { 1494 _rtld_error("Shared object \"%s\" not found, required by \"%s\"", 1495 name, basename(refobj->path)); 1496 } else { 1497 _rtld_error("Shared object \"%s\" not found", name); 1498 } 1499 return NULL; 1500} 1501 1502/* 1503 * Given a symbol number in a referencing object, find the corresponding 1504 * definition of the symbol. Returns a pointer to the symbol, or NULL if 1505 * no definition was found. Returns a pointer to the Obj_Entry of the 1506 * defining object via the reference parameter DEFOBJ_OUT. 1507 */ 1508const Elf_Sym * 1509find_symdef(unsigned long symnum, const Obj_Entry *refobj, 1510 const Obj_Entry **defobj_out, int flags, SymCache *cache, 1511 RtldLockState *lockstate) 1512{ 1513 const Elf_Sym *ref; 1514 const Elf_Sym *def; 1515 const Obj_Entry *defobj; 1516 SymLook req; 1517 const char *name; 1518 int res; 1519 1520 /* 1521 * If we have already found this symbol, get the information from 1522 * the cache. 1523 */ 1524 if (symnum >= refobj->dynsymcount) 1525 return NULL; /* Bad object */ 1526 if (cache != NULL && cache[symnum].sym != NULL) { 1527 *defobj_out = cache[symnum].obj; 1528 return cache[symnum].sym; 1529 } 1530 1531 ref = refobj->symtab + symnum; 1532 name = refobj->strtab + ref->st_name; 1533 def = NULL; 1534 defobj = NULL; 1535 1536 /* 1537 * We don't have to do a full scale lookup if the symbol is local. 1538 * We know it will bind to the instance in this load module; to 1539 * which we already have a pointer (ie ref). By not doing a lookup, 1540 * we not only improve performance, but it also avoids unresolvable 1541 * symbols when local symbols are not in the hash table. This has 1542 * been seen with the ia64 toolchain. 1543 */ 1544 if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) { 1545 if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) { 1546 _rtld_error("%s: Bogus symbol table entry %lu", refobj->path, 1547 symnum); 1548 } 1549 symlook_init(&req, name); 1550 req.flags = flags; 1551 req.ventry = fetch_ventry(refobj, symnum); 1552 req.lockstate = lockstate; 1553 res = symlook_default(&req, refobj); 1554 if (res == 0) { 1555 def = req.sym_out; 1556 defobj = req.defobj_out; 1557 } 1558 } else { 1559 def = ref; 1560 defobj = refobj; 1561 } 1562 1563 /* 1564 * If we found no definition and the reference is weak, treat the 1565 * symbol as having the value zero. 1566 */ 1567 if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) { 1568 def = &sym_zero; 1569 defobj = obj_main; 1570 } 1571 1572 if (def != NULL) { 1573 *defobj_out = defobj; 1574 /* Record the information in the cache to avoid subsequent lookups. */ 1575 if (cache != NULL) { 1576 cache[symnum].sym = def; 1577 cache[symnum].obj = defobj; 1578 } 1579 } else { 1580 if (refobj != &obj_rtld) 1581 _rtld_error("%s: Undefined symbol \"%s\"", refobj->path, name); 1582 } 1583 return def; 1584} 1585 1586/* 1587 * Return the search path from the ldconfig hints file, reading it if 1588 * necessary. If nostdlib is true, then the default search paths are 1589 * not added to result. 1590 * 1591 * Returns NULL if there are problems with the hints file, 1592 * or if the search path there is empty. 1593 */ 1594static const char * 1595gethints(bool nostdlib) 1596{ 1597 static char *hints, *filtered_path; 1598 struct elfhints_hdr hdr; 1599 struct fill_search_info_args sargs, hargs; 1600 struct dl_serinfo smeta, hmeta, *SLPinfo, *hintinfo; 1601 struct dl_serpath *SLPpath, *hintpath; 1602 char *p; 1603 unsigned int SLPndx, hintndx, fndx, fcount; 1604 int fd; 1605 size_t flen; 1606 bool skip; 1607 1608 /* First call, read the hints file */ 1609 if (hints == NULL) { 1610 /* Keep from trying again in case the hints file is bad. */ 1611 hints = ""; 1612 1613 if ((fd = open(ld_elf_hints_path, O_RDONLY | O_CLOEXEC)) == -1) 1614 return (NULL); 1615 if (read(fd, &hdr, sizeof hdr) != sizeof hdr || 1616 hdr.magic != ELFHINTS_MAGIC || 1617 hdr.version != 1) { 1618 close(fd); 1619 return (NULL); 1620 } 1621 p = xmalloc(hdr.dirlistlen + 1); 1622 if (lseek(fd, hdr.strtab + hdr.dirlist, SEEK_SET) == -1 || 1623 read(fd, p, hdr.dirlistlen + 1) != 1624 (ssize_t)hdr.dirlistlen + 1) { 1625 free(p); 1626 close(fd); 1627 return (NULL); 1628 } 1629 hints = p; 1630 close(fd); 1631 } 1632 1633 /* 1634 * If caller agreed to receive list which includes the default 1635 * paths, we are done. Otherwise, if we still did not 1636 * calculated filtered result, do it now. 1637 */ 1638 if (!nostdlib) 1639 return (hints[0] != '\0' ? hints : NULL); 1640 if (filtered_path != NULL) 1641 goto filt_ret; 1642 1643 /* 1644 * Obtain the list of all configured search paths, and the 1645 * list of the default paths. 1646 * 1647 * First estimate the size of the results. 1648 */ 1649 smeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 1650 smeta.dls_cnt = 0; 1651 hmeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 1652 hmeta.dls_cnt = 0; 1653 1654 sargs.request = RTLD_DI_SERINFOSIZE; 1655 sargs.serinfo = &smeta; 1656 hargs.request = RTLD_DI_SERINFOSIZE; 1657 hargs.serinfo = &hmeta; 1658 1659 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &sargs); 1660 path_enumerate(p, fill_search_info, &hargs); 1661 1662 SLPinfo = xmalloc(smeta.dls_size); 1663 hintinfo = xmalloc(hmeta.dls_size); 1664 1665 /* 1666 * Next fetch both sets of paths. 1667 */ 1668 sargs.request = RTLD_DI_SERINFO; 1669 sargs.serinfo = SLPinfo; 1670 sargs.serpath = &SLPinfo->dls_serpath[0]; 1671 sargs.strspace = (char *)&SLPinfo->dls_serpath[smeta.dls_cnt]; 1672 1673 hargs.request = RTLD_DI_SERINFO; 1674 hargs.serinfo = hintinfo; 1675 hargs.serpath = &hintinfo->dls_serpath[0]; 1676 hargs.strspace = (char *)&hintinfo->dls_serpath[hmeta.dls_cnt]; 1677 1678 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &sargs); 1679 path_enumerate(p, fill_search_info, &hargs); 1680 1681 /* 1682 * Now calculate the difference between two sets, by excluding 1683 * standard paths from the full set. 1684 */ 1685 fndx = 0; 1686 fcount = 0; 1687 filtered_path = xmalloc(hdr.dirlistlen + 1); 1688 hintpath = &hintinfo->dls_serpath[0]; 1689 for (hintndx = 0; hintndx < hmeta.dls_cnt; hintndx++, hintpath++) { 1690 skip = false; 1691 SLPpath = &SLPinfo->dls_serpath[0]; 1692 /* 1693 * Check each standard path against current. 1694 */ 1695 for (SLPndx = 0; SLPndx < smeta.dls_cnt; SLPndx++, SLPpath++) { 1696 /* matched, skip the path */ 1697 if (!strcmp(hintpath->dls_name, SLPpath->dls_name)) { 1698 skip = true; 1699 break; 1700 } 1701 } 1702 if (skip) 1703 continue; 1704 /* 1705 * Not matched against any standard path, add the path 1706 * to result. Separate consequtive paths with ':'. 1707 */ 1708 if (fcount > 0) { 1709 filtered_path[fndx] = ':'; 1710 fndx++; 1711 } 1712 fcount++; 1713 flen = strlen(hintpath->dls_name); 1714 strncpy((filtered_path + fndx), hintpath->dls_name, flen); 1715 fndx += flen; 1716 } 1717 filtered_path[fndx] = '\0'; 1718 1719 free(SLPinfo); 1720 free(hintinfo); 1721 1722filt_ret: 1723 return (filtered_path[0] != '\0' ? filtered_path : NULL); 1724} 1725 1726static void 1727init_dag(Obj_Entry *root) 1728{ 1729 const Needed_Entry *needed; 1730 const Objlist_Entry *elm; 1731 DoneList donelist; 1732 1733 if (root->dag_inited) 1734 return; 1735 donelist_init(&donelist); 1736 1737 /* Root object belongs to own DAG. */ 1738 objlist_push_tail(&root->dldags, root); 1739 objlist_push_tail(&root->dagmembers, root); 1740 donelist_check(&donelist, root); 1741 1742 /* 1743 * Add dependencies of root object to DAG in breadth order 1744 * by exploiting the fact that each new object get added 1745 * to the tail of the dagmembers list. 1746 */ 1747 STAILQ_FOREACH(elm, &root->dagmembers, link) { 1748 for (needed = elm->obj->needed; needed != NULL; needed = needed->next) { 1749 if (needed->obj == NULL || donelist_check(&donelist, needed->obj)) 1750 continue; 1751 objlist_push_tail(&needed->obj->dldags, root); 1752 objlist_push_tail(&root->dagmembers, needed->obj); 1753 } 1754 } 1755 root->dag_inited = true; 1756} 1757 1758static void 1759process_nodelete(Obj_Entry *root) 1760{ 1761 const Objlist_Entry *elm; 1762 1763 /* 1764 * Walk over object DAG and process every dependent object that 1765 * is marked as DF_1_NODELETE. They need to grow their own DAG, 1766 * which then should have its reference upped separately. 1767 */ 1768 STAILQ_FOREACH(elm, &root->dagmembers, link) { 1769 if (elm->obj != NULL && elm->obj->z_nodelete && 1770 !elm->obj->ref_nodel) { 1771 dbg("obj %s nodelete", elm->obj->path); 1772 init_dag(elm->obj); 1773 ref_dag(elm->obj); 1774 elm->obj->ref_nodel = true; 1775 } 1776 } 1777} 1778/* 1779 * Initialize the dynamic linker. The argument is the address at which 1780 * the dynamic linker has been mapped into memory. The primary task of 1781 * this function is to relocate the dynamic linker. 1782 */ 1783static void 1784init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info) 1785{ 1786 Obj_Entry objtmp; /* Temporary rtld object */ 1787 const Elf_Dyn *dyn_rpath; 1788 const Elf_Dyn *dyn_soname; 1789 const Elf_Dyn *dyn_runpath; 1790 1791 /* 1792 * Conjure up an Obj_Entry structure for the dynamic linker. 1793 * 1794 * The "path" member can't be initialized yet because string constants 1795 * cannot yet be accessed. Below we will set it correctly. 1796 */ 1797 memset(&objtmp, 0, sizeof(objtmp)); 1798 objtmp.path = NULL; 1799 objtmp.rtld = true; 1800 objtmp.mapbase = mapbase; 1801#ifdef PIC 1802 objtmp.relocbase = mapbase; 1803#endif 1804 if (RTLD_IS_DYNAMIC()) { 1805 objtmp.dynamic = rtld_dynamic(&objtmp); 1806 digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname, &dyn_runpath); 1807 assert(objtmp.needed == NULL); 1808#if !defined(__mips__) 1809 /* MIPS has a bogus DT_TEXTREL. */ 1810 assert(!objtmp.textrel); 1811#endif 1812 1813 /* 1814 * Temporarily put the dynamic linker entry into the object list, so 1815 * that symbols can be found. 1816 */ 1817 1818 relocate_objects(&objtmp, true, &objtmp, 0, NULL); 1819 } 1820 1821 /* Initialize the object list. */ 1822 obj_tail = &obj_list; 1823 1824 /* Now that non-local variables can be accesses, copy out obj_rtld. */ 1825 memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld)); 1826 1827 if (aux_info[AT_PAGESZ] != NULL) 1828 pagesize = aux_info[AT_PAGESZ]->a_un.a_val; 1829 if (aux_info[AT_OSRELDATE] != NULL) 1830 osreldate = aux_info[AT_OSRELDATE]->a_un.a_val; 1831 1832 digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname, dyn_runpath); 1833 1834 /* Replace the path with a dynamically allocated copy. */ 1835 obj_rtld.path = xstrdup(PATH_RTLD); 1836 1837 r_debug.r_brk = r_debug_state; 1838 r_debug.r_state = RT_CONSISTENT; 1839} 1840 1841/* 1842 * Add the init functions from a needed object list (and its recursive 1843 * needed objects) to "list". This is not used directly; it is a helper 1844 * function for initlist_add_objects(). The write lock must be held 1845 * when this function is called. 1846 */ 1847static void 1848initlist_add_neededs(Needed_Entry *needed, Objlist *list) 1849{ 1850 /* Recursively process the successor needed objects. */ 1851 if (needed->next != NULL) 1852 initlist_add_neededs(needed->next, list); 1853 1854 /* Process the current needed object. */ 1855 if (needed->obj != NULL) 1856 initlist_add_objects(needed->obj, &needed->obj->next, list); 1857} 1858 1859/* 1860 * Scan all of the DAGs rooted in the range of objects from "obj" to 1861 * "tail" and add their init functions to "list". This recurses over 1862 * the DAGs and ensure the proper init ordering such that each object's 1863 * needed libraries are initialized before the object itself. At the 1864 * same time, this function adds the objects to the global finalization 1865 * list "list_fini" in the opposite order. The write lock must be 1866 * held when this function is called. 1867 */ 1868static void 1869initlist_add_objects(Obj_Entry *obj, Obj_Entry **tail, Objlist *list) 1870{ 1871 1872 if (obj->init_scanned || obj->init_done) 1873 return; 1874 obj->init_scanned = true; 1875 1876 /* Recursively process the successor objects. */ 1877 if (&obj->next != tail) 1878 initlist_add_objects(obj->next, tail, list); 1879 1880 /* Recursively process the needed objects. */ 1881 if (obj->needed != NULL) 1882 initlist_add_neededs(obj->needed, list); 1883 if (obj->needed_filtees != NULL) 1884 initlist_add_neededs(obj->needed_filtees, list); 1885 if (obj->needed_aux_filtees != NULL) 1886 initlist_add_neededs(obj->needed_aux_filtees, list); 1887 1888 /* Add the object to the init list. */ 1889 if (obj->preinit_array != (Elf_Addr)NULL || obj->init != (Elf_Addr)NULL || 1890 obj->init_array != (Elf_Addr)NULL) 1891 objlist_push_tail(list, obj); 1892 1893 /* Add the object to the global fini list in the reverse order. */ 1894 if ((obj->fini != (Elf_Addr)NULL || obj->fini_array != (Elf_Addr)NULL) 1895 && !obj->on_fini_list) { 1896 objlist_push_head(&list_fini, obj); 1897 obj->on_fini_list = true; 1898 } 1899} 1900 1901#ifndef FPTR_TARGET 1902#define FPTR_TARGET(f) ((Elf_Addr) (f)) 1903#endif 1904 1905static void 1906free_needed_filtees(Needed_Entry *n) 1907{ 1908 Needed_Entry *needed, *needed1; 1909 1910 for (needed = n; needed != NULL; needed = needed->next) { 1911 if (needed->obj != NULL) { 1912 dlclose(needed->obj); 1913 needed->obj = NULL; 1914 } 1915 } 1916 for (needed = n; needed != NULL; needed = needed1) { 1917 needed1 = needed->next; 1918 free(needed); 1919 } 1920} 1921 1922static void 1923unload_filtees(Obj_Entry *obj) 1924{ 1925 1926 free_needed_filtees(obj->needed_filtees); 1927 obj->needed_filtees = NULL; 1928 free_needed_filtees(obj->needed_aux_filtees); 1929 obj->needed_aux_filtees = NULL; 1930 obj->filtees_loaded = false; 1931} 1932 1933static void 1934load_filtee1(Obj_Entry *obj, Needed_Entry *needed, int flags, 1935 RtldLockState *lockstate) 1936{ 1937 1938 for (; needed != NULL; needed = needed->next) { 1939 needed->obj = dlopen_object(obj->strtab + needed->name, -1, obj, 1940 flags, ((ld_loadfltr || obj->z_loadfltr) ? RTLD_NOW : RTLD_LAZY) | 1941 RTLD_LOCAL, lockstate); 1942 } 1943} 1944 1945static void 1946load_filtees(Obj_Entry *obj, int flags, RtldLockState *lockstate) 1947{ 1948 1949 lock_restart_for_upgrade(lockstate); 1950 if (!obj->filtees_loaded) { 1951 load_filtee1(obj, obj->needed_filtees, flags, lockstate); 1952 load_filtee1(obj, obj->needed_aux_filtees, flags, lockstate); 1953 obj->filtees_loaded = true; 1954 } 1955} 1956 1957static int 1958process_needed(Obj_Entry *obj, Needed_Entry *needed, int flags) 1959{ 1960 Obj_Entry *obj1; 1961 1962 for (; needed != NULL; needed = needed->next) { 1963 obj1 = needed->obj = load_object(obj->strtab + needed->name, -1, obj, 1964 flags & ~RTLD_LO_NOLOAD); 1965 if (obj1 == NULL && !ld_tracing && (flags & RTLD_LO_FILTEES) == 0) 1966 return (-1); 1967 } 1968 return (0); 1969} 1970 1971/* 1972 * Given a shared object, traverse its list of needed objects, and load 1973 * each of them. Returns 0 on success. Generates an error message and 1974 * returns -1 on failure. 1975 */ 1976static int 1977load_needed_objects(Obj_Entry *first, int flags) 1978{ 1979 Obj_Entry *obj; 1980 1981 for (obj = first; obj != NULL; obj = obj->next) { 1982 if (process_needed(obj, obj->needed, flags) == -1) 1983 return (-1); 1984 } 1985 return (0); 1986} 1987 1988static int 1989load_preload_objects(void) 1990{ 1991 char *p = ld_preload; 1992 Obj_Entry *obj; 1993 static const char delim[] = " \t:;"; 1994 1995 if (p == NULL) 1996 return 0; 1997 1998 p += strspn(p, delim); 1999 while (*p != '\0') { 2000 size_t len = strcspn(p, delim); 2001 char savech; 2002 2003 savech = p[len]; 2004 p[len] = '\0'; 2005 obj = load_object(p, -1, NULL, 0); 2006 if (obj == NULL) 2007 return -1; /* XXX - cleanup */ 2008 obj->z_interpose = true; 2009 p[len] = savech; 2010 p += len; 2011 p += strspn(p, delim); 2012 } 2013 LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL); 2014 return 0; 2015} 2016 2017static const char * 2018printable_path(const char *path) 2019{ 2020 2021 return (path == NULL ? "<unknown>" : path); 2022} 2023 2024/* 2025 * Load a shared object into memory, if it is not already loaded. The 2026 * object may be specified by name or by user-supplied file descriptor 2027 * fd_u. In the later case, the fd_u descriptor is not closed, but its 2028 * duplicate is. 2029 * 2030 * Returns a pointer to the Obj_Entry for the object. Returns NULL 2031 * on failure. 2032 */ 2033static Obj_Entry * 2034load_object(const char *name, int fd_u, const Obj_Entry *refobj, int flags) 2035{ 2036 Obj_Entry *obj; 2037 int fd; 2038 struct stat sb; 2039 char *path; 2040 2041 if (name != NULL) { 2042 for (obj = obj_list->next; obj != NULL; obj = obj->next) { 2043 if (object_match_name(obj, name)) 2044 return (obj); 2045 } 2046 2047 path = find_library(name, refobj); 2048 if (path == NULL) 2049 return (NULL); 2050 } else 2051 path = NULL; 2052 2053 /* 2054 * If we didn't find a match by pathname, or the name is not 2055 * supplied, open the file and check again by device and inode. 2056 * This avoids false mismatches caused by multiple links or ".." 2057 * in pathnames. 2058 * 2059 * To avoid a race, we open the file and use fstat() rather than 2060 * using stat(). 2061 */ 2062 fd = -1; 2063 if (fd_u == -1) { 2064 if ((fd = open(path, O_RDONLY | O_CLOEXEC)) == -1) { 2065 _rtld_error("Cannot open \"%s\"", path); 2066 free(path); 2067 return (NULL); 2068 } 2069 } else { 2070 fd = fcntl(fd_u, F_DUPFD_CLOEXEC, 0); 2071 if (fd == -1) { 2072 _rtld_error("Cannot dup fd"); 2073 free(path); 2074 return (NULL); 2075 } 2076 } 2077 if (fstat(fd, &sb) == -1) { 2078 _rtld_error("Cannot fstat \"%s\"", printable_path(path)); 2079 close(fd); 2080 free(path); 2081 return NULL; 2082 } 2083 for (obj = obj_list->next; obj != NULL; obj = obj->next) 2084 if (obj->ino == sb.st_ino && obj->dev == sb.st_dev) 2085 break; 2086 if (obj != NULL && name != NULL) { 2087 object_add_name(obj, name); 2088 free(path); 2089 close(fd); 2090 return obj; 2091 } 2092 if (flags & RTLD_LO_NOLOAD) { 2093 free(path); 2094 close(fd); 2095 return (NULL); 2096 } 2097 2098 /* First use of this object, so we must map it in */ 2099 obj = do_load_object(fd, name, path, &sb, flags); 2100 if (obj == NULL) 2101 free(path); 2102 close(fd); 2103 2104 return obj; 2105} 2106 2107static Obj_Entry * 2108do_load_object(int fd, const char *name, char *path, struct stat *sbp, 2109 int flags) 2110{ 2111 Obj_Entry *obj; 2112 struct statfs fs; 2113 2114 /* 2115 * but first, make sure that environment variables haven't been 2116 * used to circumvent the noexec flag on a filesystem. 2117 */ 2118 if (dangerous_ld_env) { 2119 if (fstatfs(fd, &fs) != 0) { 2120 _rtld_error("Cannot fstatfs \"%s\"", printable_path(path)); 2121 return NULL; 2122 } 2123 if (fs.f_flags & MNT_NOEXEC) { 2124 _rtld_error("Cannot execute objects on %s\n", fs.f_mntonname); 2125 return NULL; 2126 } 2127 } 2128 dbg("loading \"%s\"", printable_path(path)); 2129 obj = map_object(fd, printable_path(path), sbp); 2130 if (obj == NULL) 2131 return NULL; 2132 2133 /* 2134 * If DT_SONAME is present in the object, digest_dynamic2 already 2135 * added it to the object names. 2136 */ 2137 if (name != NULL) 2138 object_add_name(obj, name); 2139 obj->path = path; 2140 digest_dynamic(obj, 0); 2141 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", obj->path, 2142 obj->valid_hash_sysv, obj->valid_hash_gnu, obj->dynsymcount); 2143 if (obj->z_noopen && (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) == 2144 RTLD_LO_DLOPEN) { 2145 dbg("refusing to load non-loadable \"%s\"", obj->path); 2146 _rtld_error("Cannot dlopen non-loadable %s", obj->path); 2147 munmap(obj->mapbase, obj->mapsize); 2148 obj_free(obj); 2149 return (NULL); 2150 } 2151 2152 obj->dlopened = (flags & RTLD_LO_DLOPEN) != 0; 2153 *obj_tail = obj; 2154 obj_tail = &obj->next; 2155 obj_count++; 2156 obj_loads++; 2157 linkmap_add(obj); /* for GDB & dlinfo() */ 2158 max_stack_flags |= obj->stack_flags; 2159 2160 dbg(" %p .. %p: %s", obj->mapbase, 2161 obj->mapbase + obj->mapsize - 1, obj->path); 2162 if (obj->textrel) 2163 dbg(" WARNING: %s has impure text", obj->path); 2164 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 2165 obj->path); 2166 2167 return obj; 2168} 2169 2170static Obj_Entry * 2171obj_from_addr(const void *addr) 2172{ 2173 Obj_Entry *obj; 2174 2175 for (obj = obj_list; obj != NULL; obj = obj->next) { 2176 if (addr < (void *) obj->mapbase) 2177 continue; 2178 if (addr < (void *) (obj->mapbase + obj->mapsize)) 2179 return obj; 2180 } 2181 return NULL; 2182} 2183 2184static void 2185preinit_main(void) 2186{ 2187 Elf_Addr *preinit_addr; 2188 int index; 2189 2190 preinit_addr = (Elf_Addr *)obj_main->preinit_array; 2191 if (preinit_addr == NULL) 2192 return; 2193 2194 for (index = 0; index < obj_main->preinit_array_num; index++) { 2195 if (preinit_addr[index] != 0 && preinit_addr[index] != 1) { 2196 dbg("calling preinit function for %s at %p", obj_main->path, 2197 (void *)preinit_addr[index]); 2198 LD_UTRACE(UTRACE_INIT_CALL, obj_main, (void *)preinit_addr[index], 2199 0, 0, obj_main->path); 2200 call_init_pointer(obj_main, preinit_addr[index]); 2201 } 2202 } 2203} 2204 2205/* 2206 * Call the finalization functions for each of the objects in "list" 2207 * belonging to the DAG of "root" and referenced once. If NULL "root" 2208 * is specified, every finalization function will be called regardless 2209 * of the reference count and the list elements won't be freed. All of 2210 * the objects are expected to have non-NULL fini functions. 2211 */ 2212static void 2213objlist_call_fini(Objlist *list, Obj_Entry *root, RtldLockState *lockstate) 2214{ 2215 Objlist_Entry *elm; 2216 char *saved_msg; 2217 Elf_Addr *fini_addr; 2218 int index; 2219 2220 assert(root == NULL || root->refcount == 1); 2221 2222 /* 2223 * Preserve the current error message since a fini function might 2224 * call into the dynamic linker and overwrite it. 2225 */ 2226 saved_msg = errmsg_save(); 2227 do { 2228 STAILQ_FOREACH(elm, list, link) { 2229 if (root != NULL && (elm->obj->refcount != 1 || 2230 objlist_find(&root->dagmembers, elm->obj) == NULL)) 2231 continue; 2232 /* Remove object from fini list to prevent recursive invocation. */ 2233 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 2234 /* 2235 * XXX: If a dlopen() call references an object while the 2236 * fini function is in progress, we might end up trying to 2237 * unload the referenced object in dlclose() or the object 2238 * won't be unloaded although its fini function has been 2239 * called. 2240 */ 2241 lock_release(rtld_bind_lock, lockstate); 2242 2243 /* 2244 * It is legal to have both DT_FINI and DT_FINI_ARRAY defined. 2245 * When this happens, DT_FINI_ARRAY is processed first. 2246 */ 2247 fini_addr = (Elf_Addr *)elm->obj->fini_array; 2248 if (fini_addr != NULL && elm->obj->fini_array_num > 0) { 2249 for (index = elm->obj->fini_array_num - 1; index >= 0; 2250 index--) { 2251 if (fini_addr[index] != 0 && fini_addr[index] != 1) { 2252 dbg("calling fini function for %s at %p", 2253 elm->obj->path, (void *)fini_addr[index]); 2254 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, 2255 (void *)fini_addr[index], 0, 0, elm->obj->path); 2256 call_initfini_pointer(elm->obj, fini_addr[index]); 2257 } 2258 } 2259 } 2260 if (elm->obj->fini != (Elf_Addr)NULL) { 2261 dbg("calling fini function for %s at %p", elm->obj->path, 2262 (void *)elm->obj->fini); 2263 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, (void *)elm->obj->fini, 2264 0, 0, elm->obj->path); 2265 call_initfini_pointer(elm->obj, elm->obj->fini); 2266 } 2267 wlock_acquire(rtld_bind_lock, lockstate); 2268 /* No need to free anything if process is going down. */ 2269 if (root != NULL) 2270 free(elm); 2271 /* 2272 * We must restart the list traversal after every fini call 2273 * because a dlclose() call from the fini function or from 2274 * another thread might have modified the reference counts. 2275 */ 2276 break; 2277 } 2278 } while (elm != NULL); 2279 errmsg_restore(saved_msg); 2280} 2281 2282/* 2283 * Call the initialization functions for each of the objects in 2284 * "list". All of the objects are expected to have non-NULL init 2285 * functions. 2286 */ 2287static void 2288objlist_call_init(Objlist *list, RtldLockState *lockstate) 2289{ 2290 Objlist_Entry *elm; 2291 Obj_Entry *obj; 2292 char *saved_msg; 2293 Elf_Addr *init_addr; 2294 int index; 2295 2296 /* 2297 * Clean init_scanned flag so that objects can be rechecked and 2298 * possibly initialized earlier if any of vectors called below 2299 * cause the change by using dlopen. 2300 */ 2301 for (obj = obj_list; obj != NULL; obj = obj->next) 2302 obj->init_scanned = false; 2303 2304 /* 2305 * Preserve the current error message since an init function might 2306 * call into the dynamic linker and overwrite it. 2307 */ 2308 saved_msg = errmsg_save(); 2309 STAILQ_FOREACH(elm, list, link) { 2310 if (elm->obj->init_done) /* Initialized early. */ 2311 continue; 2312 /* 2313 * Race: other thread might try to use this object before current 2314 * one completes the initilization. Not much can be done here 2315 * without better locking. 2316 */ 2317 elm->obj->init_done = true; 2318 lock_release(rtld_bind_lock, lockstate); 2319 2320 /* 2321 * It is legal to have both DT_INIT and DT_INIT_ARRAY defined. 2322 * When this happens, DT_INIT is processed first. 2323 */ 2324 if (elm->obj->init != (Elf_Addr)NULL) { 2325 dbg("calling init function for %s at %p", elm->obj->path, 2326 (void *)elm->obj->init); 2327 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, (void *)elm->obj->init, 2328 0, 0, elm->obj->path); 2329 call_initfini_pointer(elm->obj, elm->obj->init); 2330 } 2331 init_addr = (Elf_Addr *)elm->obj->init_array; 2332 if (init_addr != NULL) { 2333 for (index = 0; index < elm->obj->init_array_num; index++) { 2334 if (init_addr[index] != 0 && init_addr[index] != 1) { 2335 dbg("calling init function for %s at %p", elm->obj->path, 2336 (void *)init_addr[index]); 2337 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, 2338 (void *)init_addr[index], 0, 0, elm->obj->path); 2339 call_init_pointer(elm->obj, init_addr[index]); 2340 } 2341 } 2342 } 2343 wlock_acquire(rtld_bind_lock, lockstate); 2344 } 2345 errmsg_restore(saved_msg); 2346} 2347 2348static void 2349objlist_clear(Objlist *list) 2350{ 2351 Objlist_Entry *elm; 2352 2353 while (!STAILQ_EMPTY(list)) { 2354 elm = STAILQ_FIRST(list); 2355 STAILQ_REMOVE_HEAD(list, link); 2356 free(elm); 2357 } 2358} 2359 2360static Objlist_Entry * 2361objlist_find(Objlist *list, const Obj_Entry *obj) 2362{ 2363 Objlist_Entry *elm; 2364 2365 STAILQ_FOREACH(elm, list, link) 2366 if (elm->obj == obj) 2367 return elm; 2368 return NULL; 2369} 2370 2371static void 2372objlist_init(Objlist *list) 2373{ 2374 STAILQ_INIT(list); 2375} 2376 2377static void 2378objlist_push_head(Objlist *list, Obj_Entry *obj) 2379{ 2380 Objlist_Entry *elm; 2381 2382 elm = NEW(Objlist_Entry); 2383 elm->obj = obj; 2384 STAILQ_INSERT_HEAD(list, elm, link); 2385} 2386 2387static void 2388objlist_push_tail(Objlist *list, Obj_Entry *obj) 2389{ 2390 Objlist_Entry *elm; 2391 2392 elm = NEW(Objlist_Entry); 2393 elm->obj = obj; 2394 STAILQ_INSERT_TAIL(list, elm, link); 2395} 2396 2397static void 2398objlist_put_after(Objlist *list, Obj_Entry *listobj, Obj_Entry *obj) 2399{ 2400 Objlist_Entry *elm, *listelm; 2401 2402 STAILQ_FOREACH(listelm, list, link) { 2403 if (listelm->obj == listobj) 2404 break; 2405 } 2406 elm = NEW(Objlist_Entry); 2407 elm->obj = obj; 2408 if (listelm != NULL) 2409 STAILQ_INSERT_AFTER(list, listelm, elm, link); 2410 else 2411 STAILQ_INSERT_TAIL(list, elm, link); 2412} 2413 2414static void 2415objlist_remove(Objlist *list, Obj_Entry *obj) 2416{ 2417 Objlist_Entry *elm; 2418 2419 if ((elm = objlist_find(list, obj)) != NULL) { 2420 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 2421 free(elm); 2422 } 2423} 2424 2425/* 2426 * Relocate dag rooted in the specified object. 2427 * Returns 0 on success, or -1 on failure. 2428 */ 2429 2430static int 2431relocate_object_dag(Obj_Entry *root, bool bind_now, Obj_Entry *rtldobj, 2432 int flags, RtldLockState *lockstate) 2433{ 2434 Objlist_Entry *elm; 2435 int error; 2436 2437 error = 0; 2438 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2439 error = relocate_object(elm->obj, bind_now, rtldobj, flags, 2440 lockstate); 2441 if (error == -1) 2442 break; 2443 } 2444 return (error); 2445} 2446 2447/* 2448 * Relocate single object. 2449 * Returns 0 on success, or -1 on failure. 2450 */ 2451static int 2452relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, 2453 int flags, RtldLockState *lockstate) 2454{ 2455 2456 if (obj->relocated) 2457 return (0); 2458 obj->relocated = true; 2459 if (obj != rtldobj) 2460 dbg("relocating \"%s\"", obj->path); 2461 2462 if (obj->symtab == NULL || obj->strtab == NULL || 2463 !(obj->valid_hash_sysv || obj->valid_hash_gnu)) { 2464 _rtld_error("%s: Shared object has no run-time symbol table", 2465 obj->path); 2466 return (-1); 2467 } 2468 2469 if (obj->textrel) { 2470 /* There are relocations to the write-protected text segment. */ 2471 if (mprotect(obj->mapbase, obj->textsize, 2472 PROT_READ|PROT_WRITE|PROT_EXEC) == -1) { 2473 _rtld_error("%s: Cannot write-enable text segment: %s", 2474 obj->path, rtld_strerror(errno)); 2475 return (-1); 2476 } 2477 } 2478 2479 /* Process the non-PLT non-IFUNC relocations. */ 2480 if (reloc_non_plt(obj, rtldobj, flags, lockstate)) 2481 return (-1); 2482 2483 if (obj->textrel) { /* Re-protected the text segment. */ 2484 if (mprotect(obj->mapbase, obj->textsize, 2485 PROT_READ|PROT_EXEC) == -1) { 2486 _rtld_error("%s: Cannot write-protect text segment: %s", 2487 obj->path, rtld_strerror(errno)); 2488 return (-1); 2489 } 2490 } 2491 2492 /* Set the special PLT or GOT entries. */ 2493 init_pltgot(obj); 2494 2495 /* Process the PLT relocations. */ 2496 if (reloc_plt(obj) == -1) 2497 return (-1); 2498 /* Relocate the jump slots if we are doing immediate binding. */ 2499 if (obj->bind_now || bind_now) 2500 if (reloc_jmpslots(obj, flags, lockstate) == -1) 2501 return (-1); 2502 2503 /* 2504 * Process the non-PLT IFUNC relocations. The relocations are 2505 * processed in two phases, because IFUNC resolvers may 2506 * reference other symbols, which must be readily processed 2507 * before resolvers are called. 2508 */ 2509 if (obj->non_plt_gnu_ifunc && 2510 reloc_non_plt(obj, rtldobj, flags | SYMLOOK_IFUNC, lockstate)) 2511 return (-1); 2512 2513 if (obj->relro_size > 0) { 2514 if (mprotect(obj->relro_page, obj->relro_size, 2515 PROT_READ) == -1) { 2516 _rtld_error("%s: Cannot enforce relro protection: %s", 2517 obj->path, rtld_strerror(errno)); 2518 return (-1); 2519 } 2520 } 2521 2522 /* 2523 * Set up the magic number and version in the Obj_Entry. These 2524 * were checked in the crt1.o from the original ElfKit, so we 2525 * set them for backward compatibility. 2526 */ 2527 obj->magic = RTLD_MAGIC; 2528 obj->version = RTLD_VERSION; 2529 2530 return (0); 2531} 2532 2533/* 2534 * Relocate newly-loaded shared objects. The argument is a pointer to 2535 * the Obj_Entry for the first such object. All objects from the first 2536 * to the end of the list of objects are relocated. Returns 0 on success, 2537 * or -1 on failure. 2538 */ 2539static int 2540relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj, 2541 int flags, RtldLockState *lockstate) 2542{ 2543 Obj_Entry *obj; 2544 int error; 2545 2546 for (error = 0, obj = first; obj != NULL; obj = obj->next) { 2547 error = relocate_object(obj, bind_now, rtldobj, flags, 2548 lockstate); 2549 if (error == -1) 2550 break; 2551 } 2552 return (error); 2553} 2554 2555/* 2556 * The handling of R_MACHINE_IRELATIVE relocations and jumpslots 2557 * referencing STT_GNU_IFUNC symbols is postponed till the other 2558 * relocations are done. The indirect functions specified as 2559 * ifunc are allowed to call other symbols, so we need to have 2560 * objects relocated before asking for resolution from indirects. 2561 * 2562 * The R_MACHINE_IRELATIVE slots are resolved in greedy fashion, 2563 * instead of the usual lazy handling of PLT slots. It is 2564 * consistent with how GNU does it. 2565 */ 2566static int 2567resolve_object_ifunc(Obj_Entry *obj, bool bind_now, int flags, 2568 RtldLockState *lockstate) 2569{ 2570 if (obj->irelative && reloc_iresolve(obj, lockstate) == -1) 2571 return (-1); 2572 if ((obj->bind_now || bind_now) && obj->gnu_ifunc && 2573 reloc_gnu_ifunc(obj, flags, lockstate) == -1) 2574 return (-1); 2575 return (0); 2576} 2577 2578static int 2579resolve_objects_ifunc(Obj_Entry *first, bool bind_now, int flags, 2580 RtldLockState *lockstate) 2581{ 2582 Obj_Entry *obj; 2583 2584 for (obj = first; obj != NULL; obj = obj->next) { 2585 if (resolve_object_ifunc(obj, bind_now, flags, lockstate) == -1) 2586 return (-1); 2587 } 2588 return (0); 2589} 2590 2591static int 2592initlist_objects_ifunc(Objlist *list, bool bind_now, int flags, 2593 RtldLockState *lockstate) 2594{ 2595 Objlist_Entry *elm; 2596 2597 STAILQ_FOREACH(elm, list, link) { 2598 if (resolve_object_ifunc(elm->obj, bind_now, flags, 2599 lockstate) == -1) 2600 return (-1); 2601 } 2602 return (0); 2603} 2604 2605/* 2606 * Cleanup procedure. It will be called (by the atexit mechanism) just 2607 * before the process exits. 2608 */ 2609static void 2610rtld_exit(void) 2611{ 2612 RtldLockState lockstate; 2613 2614 wlock_acquire(rtld_bind_lock, &lockstate); 2615 dbg("rtld_exit()"); 2616 objlist_call_fini(&list_fini, NULL, &lockstate); 2617 /* No need to remove the items from the list, since we are exiting. */ 2618 if (!libmap_disable) 2619 lm_fini(); 2620 lock_release(rtld_bind_lock, &lockstate); 2621} 2622 2623/* 2624 * Iterate over a search path, translate each element, and invoke the 2625 * callback on the result. 2626 */ 2627static void * 2628path_enumerate(const char *path, path_enum_proc callback, void *arg) 2629{ 2630 const char *trans; 2631 if (path == NULL) 2632 return (NULL); 2633 2634 path += strspn(path, ":;"); 2635 while (*path != '\0') { 2636 size_t len; 2637 char *res; 2638 2639 len = strcspn(path, ":;"); 2640 trans = lm_findn(NULL, path, len); 2641 if (trans) 2642 res = callback(trans, strlen(trans), arg); 2643 else 2644 res = callback(path, len, arg); 2645 2646 if (res != NULL) 2647 return (res); 2648 2649 path += len; 2650 path += strspn(path, ":;"); 2651 } 2652 2653 return (NULL); 2654} 2655 2656struct try_library_args { 2657 const char *name; 2658 size_t namelen; 2659 char *buffer; 2660 size_t buflen; 2661}; 2662 2663static void * 2664try_library_path(const char *dir, size_t dirlen, void *param) 2665{ 2666 struct try_library_args *arg; 2667 2668 arg = param; 2669 if (*dir == '/' || trust) { 2670 char *pathname; 2671 2672 if (dirlen + 1 + arg->namelen + 1 > arg->buflen) 2673 return (NULL); 2674 2675 pathname = arg->buffer; 2676 strncpy(pathname, dir, dirlen); 2677 pathname[dirlen] = '/'; 2678 strcpy(pathname + dirlen + 1, arg->name); 2679 2680 dbg(" Trying \"%s\"", pathname); 2681 if (access(pathname, F_OK) == 0) { /* We found it */ 2682 pathname = xmalloc(dirlen + 1 + arg->namelen + 1); 2683 strcpy(pathname, arg->buffer); 2684 return (pathname); 2685 } 2686 } 2687 return (NULL); 2688} 2689 2690static char * 2691search_library_path(const char *name, const char *path) 2692{ 2693 char *p; 2694 struct try_library_args arg; 2695 2696 if (path == NULL) 2697 return NULL; 2698 2699 arg.name = name; 2700 arg.namelen = strlen(name); 2701 arg.buffer = xmalloc(PATH_MAX); 2702 arg.buflen = PATH_MAX; 2703 2704 p = path_enumerate(path, try_library_path, &arg); 2705 2706 free(arg.buffer); 2707 2708 return (p); 2709} 2710 2711int 2712dlclose(void *handle) 2713{ 2714 Obj_Entry *root; 2715 RtldLockState lockstate; 2716 2717 wlock_acquire(rtld_bind_lock, &lockstate); 2718 root = dlcheck(handle); 2719 if (root == NULL) { 2720 lock_release(rtld_bind_lock, &lockstate); 2721 return -1; 2722 } 2723 LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount, 2724 root->path); 2725 2726 /* Unreference the object and its dependencies. */ 2727 root->dl_refcount--; 2728 2729 if (root->refcount == 1) { 2730 /* 2731 * The object will be no longer referenced, so we must unload it. 2732 * First, call the fini functions. 2733 */ 2734 objlist_call_fini(&list_fini, root, &lockstate); 2735 2736 unref_dag(root); 2737 2738 /* Finish cleaning up the newly-unreferenced objects. */ 2739 GDB_STATE(RT_DELETE,&root->linkmap); 2740 unload_object(root); 2741 GDB_STATE(RT_CONSISTENT,NULL); 2742 } else 2743 unref_dag(root); 2744 2745 LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL); 2746 lock_release(rtld_bind_lock, &lockstate); 2747 return 0; 2748} 2749 2750char * 2751dlerror(void) 2752{ 2753 char *msg = error_message; 2754 error_message = NULL; 2755 return msg; 2756} 2757 2758/* 2759 * This function is deprecated and has no effect. 2760 */ 2761void 2762dllockinit(void *context, 2763 void *(*lock_create)(void *context), 2764 void (*rlock_acquire)(void *lock), 2765 void (*wlock_acquire)(void *lock), 2766 void (*lock_release)(void *lock), 2767 void (*lock_destroy)(void *lock), 2768 void (*context_destroy)(void *context)) 2769{ 2770 static void *cur_context; 2771 static void (*cur_context_destroy)(void *); 2772 2773 /* Just destroy the context from the previous call, if necessary. */ 2774 if (cur_context_destroy != NULL) 2775 cur_context_destroy(cur_context); 2776 cur_context = context; 2777 cur_context_destroy = context_destroy; 2778} 2779 2780void * 2781dlopen(const char *name, int mode) 2782{ 2783 2784 return (rtld_dlopen(name, -1, mode)); 2785} 2786 2787void * 2788fdlopen(int fd, int mode) 2789{ 2790 2791 return (rtld_dlopen(NULL, fd, mode)); 2792} 2793 2794static void * 2795rtld_dlopen(const char *name, int fd, int mode) 2796{ 2797 RtldLockState lockstate; 2798 int lo_flags; 2799 2800 LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name); 2801 ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1"; 2802 if (ld_tracing != NULL) { 2803 rlock_acquire(rtld_bind_lock, &lockstate); 2804 if (sigsetjmp(lockstate.env, 0) != 0) 2805 lock_upgrade(rtld_bind_lock, &lockstate); 2806 environ = (char **)*get_program_var_addr("environ", &lockstate); 2807 lock_release(rtld_bind_lock, &lockstate); 2808 } 2809 lo_flags = RTLD_LO_DLOPEN; 2810 if (mode & RTLD_NODELETE) 2811 lo_flags |= RTLD_LO_NODELETE; 2812 if (mode & RTLD_NOLOAD) 2813 lo_flags |= RTLD_LO_NOLOAD; 2814 if (ld_tracing != NULL) 2815 lo_flags |= RTLD_LO_TRACE; 2816 2817 return (dlopen_object(name, fd, obj_main, lo_flags, 2818 mode & (RTLD_MODEMASK | RTLD_GLOBAL), NULL)); 2819} 2820 2821static void 2822dlopen_cleanup(Obj_Entry *obj) 2823{ 2824 2825 obj->dl_refcount--; 2826 unref_dag(obj); 2827 if (obj->refcount == 0) 2828 unload_object(obj); 2829} 2830 2831static Obj_Entry * 2832dlopen_object(const char *name, int fd, Obj_Entry *refobj, int lo_flags, 2833 int mode, RtldLockState *lockstate) 2834{ 2835 Obj_Entry **old_obj_tail; 2836 Obj_Entry *obj; 2837 Objlist initlist; 2838 RtldLockState mlockstate; 2839 int result; 2840 2841 objlist_init(&initlist); 2842 2843 if (lockstate == NULL && !(lo_flags & RTLD_LO_EARLY)) { 2844 wlock_acquire(rtld_bind_lock, &mlockstate); 2845 lockstate = &mlockstate; 2846 } 2847 GDB_STATE(RT_ADD,NULL); 2848 2849 old_obj_tail = obj_tail; 2850 obj = NULL; 2851 if (name == NULL && fd == -1) { 2852 obj = obj_main; 2853 obj->refcount++; 2854 } else { 2855 obj = load_object(name, fd, refobj, lo_flags); 2856 } 2857 2858 if (obj) { 2859 obj->dl_refcount++; 2860 if (mode & RTLD_GLOBAL && objlist_find(&list_global, obj) == NULL) 2861 objlist_push_tail(&list_global, obj); 2862 if (*old_obj_tail != NULL) { /* We loaded something new. */ 2863 assert(*old_obj_tail == obj); 2864 result = load_needed_objects(obj, 2865 lo_flags & (RTLD_LO_DLOPEN | RTLD_LO_EARLY)); 2866 init_dag(obj); 2867 ref_dag(obj); 2868 if (result != -1) 2869 result = rtld_verify_versions(&obj->dagmembers); 2870 if (result != -1 && ld_tracing) 2871 goto trace; 2872 if (result == -1 || relocate_object_dag(obj, 2873 (mode & RTLD_MODEMASK) == RTLD_NOW, &obj_rtld, 2874 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 2875 lockstate) == -1) { 2876 dlopen_cleanup(obj); 2877 obj = NULL; 2878 } else if (lo_flags & RTLD_LO_EARLY) { 2879 /* 2880 * Do not call the init functions for early loaded 2881 * filtees. The image is still not initialized enough 2882 * for them to work. 2883 * 2884 * Our object is found by the global object list and 2885 * will be ordered among all init calls done right 2886 * before transferring control to main. 2887 */ 2888 } else { 2889 /* Make list of init functions to call. */ 2890 initlist_add_objects(obj, &obj->next, &initlist); 2891 } 2892 /* 2893 * Process all no_delete objects here, given them own 2894 * DAGs to prevent their dependencies from being unloaded. 2895 * This has to be done after we have loaded all of the 2896 * dependencies, so that we do not miss any. 2897 */ 2898 if (obj != NULL) 2899 process_nodelete(obj); 2900 } else { 2901 /* 2902 * Bump the reference counts for objects on this DAG. If 2903 * this is the first dlopen() call for the object that was 2904 * already loaded as a dependency, initialize the dag 2905 * starting at it. 2906 */ 2907 init_dag(obj); 2908 ref_dag(obj); 2909 2910 if ((lo_flags & RTLD_LO_TRACE) != 0) 2911 goto trace; 2912 } 2913 if (obj != NULL && ((lo_flags & RTLD_LO_NODELETE) != 0 || 2914 obj->z_nodelete) && !obj->ref_nodel) { 2915 dbg("obj %s nodelete", obj->path); 2916 ref_dag(obj); 2917 obj->z_nodelete = obj->ref_nodel = true; 2918 } 2919 } 2920 2921 LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0, 2922 name); 2923 GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL); 2924 2925 if (!(lo_flags & RTLD_LO_EARLY)) { 2926 map_stacks_exec(lockstate); 2927 } 2928 2929 if (initlist_objects_ifunc(&initlist, (mode & RTLD_MODEMASK) == RTLD_NOW, 2930 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 2931 lockstate) == -1) { 2932 objlist_clear(&initlist); 2933 dlopen_cleanup(obj); 2934 if (lockstate == &mlockstate) 2935 lock_release(rtld_bind_lock, lockstate); 2936 return (NULL); 2937 } 2938 2939 if (!(lo_flags & RTLD_LO_EARLY)) { 2940 /* Call the init functions. */ 2941 objlist_call_init(&initlist, lockstate); 2942 } 2943 objlist_clear(&initlist); 2944 if (lockstate == &mlockstate) 2945 lock_release(rtld_bind_lock, lockstate); 2946 return obj; 2947trace: 2948 trace_loaded_objects(obj); 2949 if (lockstate == &mlockstate) 2950 lock_release(rtld_bind_lock, lockstate); 2951 exit(0); 2952} 2953 2954static void * 2955do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve, 2956 int flags) 2957{ 2958 DoneList donelist; 2959 const Obj_Entry *obj, *defobj; 2960 const Elf_Sym *def; 2961 SymLook req; 2962 RtldLockState lockstate; 2963#ifndef __ia64__ 2964 tls_index ti; 2965#endif 2966 int res; 2967 2968 def = NULL; 2969 defobj = NULL; 2970 symlook_init(&req, name); 2971 req.ventry = ve; 2972 req.flags = flags | SYMLOOK_IN_PLT; 2973 req.lockstate = &lockstate; 2974 2975 rlock_acquire(rtld_bind_lock, &lockstate); 2976 if (sigsetjmp(lockstate.env, 0) != 0) 2977 lock_upgrade(rtld_bind_lock, &lockstate); 2978 if (handle == NULL || handle == RTLD_NEXT || 2979 handle == RTLD_DEFAULT || handle == RTLD_SELF) { 2980 2981 if ((obj = obj_from_addr(retaddr)) == NULL) { 2982 _rtld_error("Cannot determine caller's shared object"); 2983 lock_release(rtld_bind_lock, &lockstate); 2984 return NULL; 2985 } 2986 if (handle == NULL) { /* Just the caller's shared object. */ 2987 res = symlook_obj(&req, obj); 2988 if (res == 0) { 2989 def = req.sym_out; 2990 defobj = req.defobj_out; 2991 } 2992 } else if (handle == RTLD_NEXT || /* Objects after caller's */ 2993 handle == RTLD_SELF) { /* ... caller included */ 2994 if (handle == RTLD_NEXT) 2995 obj = obj->next; 2996 for (; obj != NULL; obj = obj->next) { 2997 res = symlook_obj(&req, obj); 2998 if (res == 0) { 2999 if (def == NULL || 3000 ELF_ST_BIND(req.sym_out->st_info) != STB_WEAK) { 3001 def = req.sym_out; 3002 defobj = req.defobj_out; 3003 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 3004 break; 3005 } 3006 } 3007 } 3008 /* 3009 * Search the dynamic linker itself, and possibly resolve the 3010 * symbol from there. This is how the application links to 3011 * dynamic linker services such as dlopen. 3012 */ 3013 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 3014 res = symlook_obj(&req, &obj_rtld); 3015 if (res == 0) { 3016 def = req.sym_out; 3017 defobj = req.defobj_out; 3018 } 3019 } 3020 } else { 3021 assert(handle == RTLD_DEFAULT); 3022 res = symlook_default(&req, obj); 3023 if (res == 0) { 3024 defobj = req.defobj_out; 3025 def = req.sym_out; 3026 } 3027 } 3028 } else { 3029 if ((obj = dlcheck(handle)) == NULL) { 3030 lock_release(rtld_bind_lock, &lockstate); 3031 return NULL; 3032 } 3033 3034 donelist_init(&donelist); 3035 if (obj->mainprog) { 3036 /* Handle obtained by dlopen(NULL, ...) implies global scope. */ 3037 res = symlook_global(&req, &donelist); 3038 if (res == 0) { 3039 def = req.sym_out; 3040 defobj = req.defobj_out; 3041 } 3042 /* 3043 * Search the dynamic linker itself, and possibly resolve the 3044 * symbol from there. This is how the application links to 3045 * dynamic linker services such as dlopen. 3046 */ 3047 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 3048 res = symlook_obj(&req, &obj_rtld); 3049 if (res == 0) { 3050 def = req.sym_out; 3051 defobj = req.defobj_out; 3052 } 3053 } 3054 } 3055 else { 3056 /* Search the whole DAG rooted at the given object. */ 3057 res = symlook_list(&req, &obj->dagmembers, &donelist); 3058 if (res == 0) { 3059 def = req.sym_out; 3060 defobj = req.defobj_out; 3061 } 3062 } 3063 } 3064 3065 if (def != NULL) { 3066 lock_release(rtld_bind_lock, &lockstate); 3067 3068 /* 3069 * The value required by the caller is derived from the value 3070 * of the symbol. For the ia64 architecture, we need to 3071 * construct a function descriptor which the caller can use to 3072 * call the function with the right 'gp' value. For other 3073 * architectures and for non-functions, the value is simply 3074 * the relocated value of the symbol. 3075 */ 3076 if (ELF_ST_TYPE(def->st_info) == STT_FUNC) 3077 return (make_function_pointer(def, defobj)); 3078 else if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 3079 return (rtld_resolve_ifunc(defobj, def)); 3080 else if (ELF_ST_TYPE(def->st_info) == STT_TLS) { 3081#ifdef __ia64__ 3082 return (__tls_get_addr(defobj->tlsindex, def->st_value)); 3083#else 3084 ti.ti_module = defobj->tlsindex; 3085 ti.ti_offset = def->st_value; 3086 return (__tls_get_addr(&ti)); 3087#endif 3088 } else 3089 return (defobj->relocbase + def->st_value); 3090 } 3091 3092 _rtld_error("Undefined symbol \"%s\"", name); 3093 lock_release(rtld_bind_lock, &lockstate); 3094 return NULL; 3095} 3096 3097void * 3098dlsym(void *handle, const char *name) 3099{ 3100 return do_dlsym(handle, name, __builtin_return_address(0), NULL, 3101 SYMLOOK_DLSYM); 3102} 3103 3104dlfunc_t 3105dlfunc(void *handle, const char *name) 3106{ 3107 union { 3108 void *d; 3109 dlfunc_t f; 3110 } rv; 3111 3112 rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL, 3113 SYMLOOK_DLSYM); 3114 return (rv.f); 3115} 3116 3117void * 3118dlvsym(void *handle, const char *name, const char *version) 3119{ 3120 Ver_Entry ventry; 3121 3122 ventry.name = version; 3123 ventry.file = NULL; 3124 ventry.hash = elf_hash(version); 3125 ventry.flags= 0; 3126 return do_dlsym(handle, name, __builtin_return_address(0), &ventry, 3127 SYMLOOK_DLSYM); 3128} 3129 3130int 3131_rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info) 3132{ 3133 const Obj_Entry *obj; 3134 RtldLockState lockstate; 3135 3136 rlock_acquire(rtld_bind_lock, &lockstate); 3137 obj = obj_from_addr(addr); 3138 if (obj == NULL) { 3139 _rtld_error("No shared object contains address"); 3140 lock_release(rtld_bind_lock, &lockstate); 3141 return (0); 3142 } 3143 rtld_fill_dl_phdr_info(obj, phdr_info); 3144 lock_release(rtld_bind_lock, &lockstate); 3145 return (1); 3146} 3147 3148int 3149dladdr(const void *addr, Dl_info *info) 3150{ 3151 const Obj_Entry *obj; 3152 const Elf_Sym *def; 3153 void *symbol_addr; 3154 unsigned long symoffset; 3155 RtldLockState lockstate; 3156 3157 rlock_acquire(rtld_bind_lock, &lockstate); 3158 obj = obj_from_addr(addr); 3159 if (obj == NULL) { 3160 _rtld_error("No shared object contains address"); 3161 lock_release(rtld_bind_lock, &lockstate); 3162 return 0; 3163 } 3164 info->dli_fname = obj->path; 3165 info->dli_fbase = obj->mapbase; 3166 info->dli_saddr = (void *)0; 3167 info->dli_sname = NULL; 3168 3169 /* 3170 * Walk the symbol list looking for the symbol whose address is 3171 * closest to the address sent in. 3172 */ 3173 for (symoffset = 0; symoffset < obj->dynsymcount; symoffset++) { 3174 def = obj->symtab + symoffset; 3175 3176 /* 3177 * For skip the symbol if st_shndx is either SHN_UNDEF or 3178 * SHN_COMMON. 3179 */ 3180 if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON) 3181 continue; 3182 3183 /* 3184 * If the symbol is greater than the specified address, or if it 3185 * is further away from addr than the current nearest symbol, 3186 * then reject it. 3187 */ 3188 symbol_addr = obj->relocbase + def->st_value; 3189 if (symbol_addr > addr || symbol_addr < info->dli_saddr) 3190 continue; 3191 3192 /* Update our idea of the nearest symbol. */ 3193 info->dli_sname = obj->strtab + def->st_name; 3194 info->dli_saddr = symbol_addr; 3195 3196 /* Exact match? */ 3197 if (info->dli_saddr == addr) 3198 break; 3199 } 3200 lock_release(rtld_bind_lock, &lockstate); 3201 return 1; 3202} 3203 3204int 3205dlinfo(void *handle, int request, void *p) 3206{ 3207 const Obj_Entry *obj; 3208 RtldLockState lockstate; 3209 int error; 3210 3211 rlock_acquire(rtld_bind_lock, &lockstate); 3212 3213 if (handle == NULL || handle == RTLD_SELF) { 3214 void *retaddr; 3215 3216 retaddr = __builtin_return_address(0); /* __GNUC__ only */ 3217 if ((obj = obj_from_addr(retaddr)) == NULL) 3218 _rtld_error("Cannot determine caller's shared object"); 3219 } else 3220 obj = dlcheck(handle); 3221 3222 if (obj == NULL) { 3223 lock_release(rtld_bind_lock, &lockstate); 3224 return (-1); 3225 } 3226 3227 error = 0; 3228 switch (request) { 3229 case RTLD_DI_LINKMAP: 3230 *((struct link_map const **)p) = &obj->linkmap; 3231 break; 3232 case RTLD_DI_ORIGIN: 3233 error = rtld_dirname(obj->path, p); 3234 break; 3235 3236 case RTLD_DI_SERINFOSIZE: 3237 case RTLD_DI_SERINFO: 3238 error = do_search_info(obj, request, (struct dl_serinfo *)p); 3239 break; 3240 3241 default: 3242 _rtld_error("Invalid request %d passed to dlinfo()", request); 3243 error = -1; 3244 } 3245 3246 lock_release(rtld_bind_lock, &lockstate); 3247 3248 return (error); 3249} 3250 3251static void 3252rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info) 3253{ 3254 3255 phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase; 3256 phdr_info->dlpi_name = obj->path; 3257 phdr_info->dlpi_phdr = obj->phdr; 3258 phdr_info->dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]); 3259 phdr_info->dlpi_tls_modid = obj->tlsindex; 3260 phdr_info->dlpi_tls_data = obj->tlsinit; 3261 phdr_info->dlpi_adds = obj_loads; 3262 phdr_info->dlpi_subs = obj_loads - obj_count; 3263} 3264 3265int 3266dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param) 3267{ 3268 struct dl_phdr_info phdr_info; 3269 const Obj_Entry *obj; 3270 RtldLockState bind_lockstate, phdr_lockstate; 3271 int error; 3272 3273 wlock_acquire(rtld_phdr_lock, &phdr_lockstate); 3274 rlock_acquire(rtld_bind_lock, &bind_lockstate); 3275 3276 error = 0; 3277 3278 for (obj = obj_list; obj != NULL; obj = obj->next) { 3279 rtld_fill_dl_phdr_info(obj, &phdr_info); 3280 if ((error = callback(&phdr_info, sizeof phdr_info, param)) != 0) 3281 break; 3282 3283 } 3284 lock_release(rtld_bind_lock, &bind_lockstate); 3285 lock_release(rtld_phdr_lock, &phdr_lockstate); 3286 3287 return (error); 3288} 3289 3290static void * 3291fill_search_info(const char *dir, size_t dirlen, void *param) 3292{ 3293 struct fill_search_info_args *arg; 3294 3295 arg = param; 3296 3297 if (arg->request == RTLD_DI_SERINFOSIZE) { 3298 arg->serinfo->dls_cnt ++; 3299 arg->serinfo->dls_size += sizeof(struct dl_serpath) + dirlen + 1; 3300 } else { 3301 struct dl_serpath *s_entry; 3302 3303 s_entry = arg->serpath; 3304 s_entry->dls_name = arg->strspace; 3305 s_entry->dls_flags = arg->flags; 3306 3307 strncpy(arg->strspace, dir, dirlen); 3308 arg->strspace[dirlen] = '\0'; 3309 3310 arg->strspace += dirlen + 1; 3311 arg->serpath++; 3312 } 3313 3314 return (NULL); 3315} 3316 3317static int 3318do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info) 3319{ 3320 struct dl_serinfo _info; 3321 struct fill_search_info_args args; 3322 3323 args.request = RTLD_DI_SERINFOSIZE; 3324 args.serinfo = &_info; 3325 3326 _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 3327 _info.dls_cnt = 0; 3328 3329 path_enumerate(obj->rpath, fill_search_info, &args); 3330 path_enumerate(ld_library_path, fill_search_info, &args); 3331 path_enumerate(obj->runpath, fill_search_info, &args); 3332 path_enumerate(gethints(obj->z_nodeflib), fill_search_info, &args); 3333 if (!obj->z_nodeflib) 3334 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args); 3335 3336 3337 if (request == RTLD_DI_SERINFOSIZE) { 3338 info->dls_size = _info.dls_size; 3339 info->dls_cnt = _info.dls_cnt; 3340 return (0); 3341 } 3342 3343 if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) { 3344 _rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()"); 3345 return (-1); 3346 } 3347 3348 args.request = RTLD_DI_SERINFO; 3349 args.serinfo = info; 3350 args.serpath = &info->dls_serpath[0]; 3351 args.strspace = (char *)&info->dls_serpath[_info.dls_cnt]; 3352 3353 args.flags = LA_SER_RUNPATH; 3354 if (path_enumerate(obj->rpath, fill_search_info, &args) != NULL) 3355 return (-1); 3356 3357 args.flags = LA_SER_LIBPATH; 3358 if (path_enumerate(ld_library_path, fill_search_info, &args) != NULL) 3359 return (-1); 3360 3361 args.flags = LA_SER_RUNPATH; 3362 if (path_enumerate(obj->runpath, fill_search_info, &args) != NULL) 3363 return (-1); 3364 3365 args.flags = LA_SER_CONFIG; 3366 if (path_enumerate(gethints(obj->z_nodeflib), fill_search_info, &args) 3367 != NULL) 3368 return (-1); 3369 3370 args.flags = LA_SER_DEFAULT; 3371 if (!obj->z_nodeflib && 3372 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args) != NULL) 3373 return (-1); 3374 return (0); 3375} 3376 3377static int 3378rtld_dirname(const char *path, char *bname) 3379{ 3380 const char *endp; 3381 3382 /* Empty or NULL string gets treated as "." */ 3383 if (path == NULL || *path == '\0') { 3384 bname[0] = '.'; 3385 bname[1] = '\0'; 3386 return (0); 3387 } 3388 3389 /* Strip trailing slashes */ 3390 endp = path + strlen(path) - 1; 3391 while (endp > path && *endp == '/') 3392 endp--; 3393 3394 /* Find the start of the dir */ 3395 while (endp > path && *endp != '/') 3396 endp--; 3397 3398 /* Either the dir is "/" or there are no slashes */ 3399 if (endp == path) { 3400 bname[0] = *endp == '/' ? '/' : '.'; 3401 bname[1] = '\0'; 3402 return (0); 3403 } else { 3404 do { 3405 endp--; 3406 } while (endp > path && *endp == '/'); 3407 } 3408 3409 if (endp - path + 2 > PATH_MAX) 3410 { 3411 _rtld_error("Filename is too long: %s", path); 3412 return(-1); 3413 } 3414 3415 strncpy(bname, path, endp - path + 1); 3416 bname[endp - path + 1] = '\0'; 3417 return (0); 3418} 3419 3420static int 3421rtld_dirname_abs(const char *path, char *base) 3422{ 3423 char base_rel[PATH_MAX]; 3424 3425 if (rtld_dirname(path, base) == -1) 3426 return (-1); 3427 if (base[0] == '/') 3428 return (0); 3429 if (getcwd(base_rel, sizeof(base_rel)) == NULL || 3430 strlcat(base_rel, "/", sizeof(base_rel)) >= sizeof(base_rel) || 3431 strlcat(base_rel, base, sizeof(base_rel)) >= sizeof(base_rel)) 3432 return (-1); 3433 strcpy(base, base_rel); 3434 return (0); 3435} 3436 3437static void 3438linkmap_add(Obj_Entry *obj) 3439{ 3440 struct link_map *l = &obj->linkmap; 3441 struct link_map *prev; 3442 3443 obj->linkmap.l_name = obj->path; 3444 obj->linkmap.l_addr = obj->mapbase; 3445 obj->linkmap.l_ld = obj->dynamic; 3446#ifdef __mips__ 3447 /* GDB needs load offset on MIPS to use the symbols */ 3448 obj->linkmap.l_offs = obj->relocbase; 3449#endif 3450 3451 if (r_debug.r_map == NULL) { 3452 r_debug.r_map = l; 3453 return; 3454 } 3455 3456 /* 3457 * Scan to the end of the list, but not past the entry for the 3458 * dynamic linker, which we want to keep at the very end. 3459 */ 3460 for (prev = r_debug.r_map; 3461 prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap; 3462 prev = prev->l_next) 3463 ; 3464 3465 /* Link in the new entry. */ 3466 l->l_prev = prev; 3467 l->l_next = prev->l_next; 3468 if (l->l_next != NULL) 3469 l->l_next->l_prev = l; 3470 prev->l_next = l; 3471} 3472 3473static void 3474linkmap_delete(Obj_Entry *obj) 3475{ 3476 struct link_map *l = &obj->linkmap; 3477 3478 if (l->l_prev == NULL) { 3479 if ((r_debug.r_map = l->l_next) != NULL) 3480 l->l_next->l_prev = NULL; 3481 return; 3482 } 3483 3484 if ((l->l_prev->l_next = l->l_next) != NULL) 3485 l->l_next->l_prev = l->l_prev; 3486} 3487 3488/* 3489 * Function for the debugger to set a breakpoint on to gain control. 3490 * 3491 * The two parameters allow the debugger to easily find and determine 3492 * what the runtime loader is doing and to whom it is doing it. 3493 * 3494 * When the loadhook trap is hit (r_debug_state, set at program 3495 * initialization), the arguments can be found on the stack: 3496 * 3497 * +8 struct link_map *m 3498 * +4 struct r_debug *rd 3499 * +0 RetAddr 3500 */ 3501void 3502r_debug_state(struct r_debug* rd, struct link_map *m) 3503{ 3504 /* 3505 * The following is a hack to force the compiler to emit calls to 3506 * this function, even when optimizing. If the function is empty, 3507 * the compiler is not obliged to emit any code for calls to it, 3508 * even when marked __noinline. However, gdb depends on those 3509 * calls being made. 3510 */ 3511 __compiler_membar(); 3512} 3513 3514/* 3515 * A function called after init routines have completed. This can be used to 3516 * break before a program's entry routine is called, and can be used when 3517 * main is not available in the symbol table. 3518 */ 3519void 3520_r_debug_postinit(struct link_map *m) 3521{ 3522 3523 /* See r_debug_state(). */ 3524 __compiler_membar(); 3525} 3526 3527/* 3528 * Get address of the pointer variable in the main program. 3529 * Prefer non-weak symbol over the weak one. 3530 */ 3531static const void ** 3532get_program_var_addr(const char *name, RtldLockState *lockstate) 3533{ 3534 SymLook req; 3535 DoneList donelist; 3536 3537 symlook_init(&req, name); 3538 req.lockstate = lockstate; 3539 donelist_init(&donelist); 3540 if (symlook_global(&req, &donelist) != 0) 3541 return (NULL); 3542 if (ELF_ST_TYPE(req.sym_out->st_info) == STT_FUNC) 3543 return ((const void **)make_function_pointer(req.sym_out, 3544 req.defobj_out)); 3545 else if (ELF_ST_TYPE(req.sym_out->st_info) == STT_GNU_IFUNC) 3546 return ((const void **)rtld_resolve_ifunc(req.defobj_out, req.sym_out)); 3547 else 3548 return ((const void **)(req.defobj_out->relocbase + 3549 req.sym_out->st_value)); 3550} 3551 3552/* 3553 * Set a pointer variable in the main program to the given value. This 3554 * is used to set key variables such as "environ" before any of the 3555 * init functions are called. 3556 */ 3557static void 3558set_program_var(const char *name, const void *value) 3559{ 3560 const void **addr; 3561 3562 if ((addr = get_program_var_addr(name, NULL)) != NULL) { 3563 dbg("\"%s\": *%p <-- %p", name, addr, value); 3564 *addr = value; 3565 } 3566} 3567 3568/* 3569 * Search the global objects, including dependencies and main object, 3570 * for the given symbol. 3571 */ 3572static int 3573symlook_global(SymLook *req, DoneList *donelist) 3574{ 3575 SymLook req1; 3576 const Objlist_Entry *elm; 3577 int res; 3578 3579 symlook_init_from_req(&req1, req); 3580 3581 /* Search all objects loaded at program start up. */ 3582 if (req->defobj_out == NULL || 3583 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 3584 res = symlook_list(&req1, &list_main, donelist); 3585 if (res == 0 && (req->defobj_out == NULL || 3586 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 3587 req->sym_out = req1.sym_out; 3588 req->defobj_out = req1.defobj_out; 3589 assert(req->defobj_out != NULL); 3590 } 3591 } 3592 3593 /* Search all DAGs whose roots are RTLD_GLOBAL objects. */ 3594 STAILQ_FOREACH(elm, &list_global, link) { 3595 if (req->defobj_out != NULL && 3596 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK) 3597 break; 3598 res = symlook_list(&req1, &elm->obj->dagmembers, donelist); 3599 if (res == 0 && (req->defobj_out == NULL || 3600 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 3601 req->sym_out = req1.sym_out; 3602 req->defobj_out = req1.defobj_out; 3603 assert(req->defobj_out != NULL); 3604 } 3605 } 3606 3607 return (req->sym_out != NULL ? 0 : ESRCH); 3608} 3609 3610/* 3611 * Given a symbol name in a referencing object, find the corresponding 3612 * definition of the symbol. Returns a pointer to the symbol, or NULL if 3613 * no definition was found. Returns a pointer to the Obj_Entry of the 3614 * defining object via the reference parameter DEFOBJ_OUT. 3615 */ 3616static int 3617symlook_default(SymLook *req, const Obj_Entry *refobj) 3618{ 3619 DoneList donelist; 3620 const Objlist_Entry *elm; 3621 SymLook req1; 3622 int res; 3623 3624 donelist_init(&donelist); 3625 symlook_init_from_req(&req1, req); 3626 3627 /* Look first in the referencing object if linked symbolically. */ 3628 if (refobj->symbolic && !donelist_check(&donelist, refobj)) { 3629 res = symlook_obj(&req1, refobj); 3630 if (res == 0) { 3631 req->sym_out = req1.sym_out; 3632 req->defobj_out = req1.defobj_out; 3633 assert(req->defobj_out != NULL); 3634 } 3635 } 3636 3637 symlook_global(req, &donelist); 3638 3639 /* Search all dlopened DAGs containing the referencing object. */ 3640 STAILQ_FOREACH(elm, &refobj->dldags, link) { 3641 if (req->sym_out != NULL && 3642 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK) 3643 break; 3644 res = symlook_list(&req1, &elm->obj->dagmembers, &donelist); 3645 if (res == 0 && (req->sym_out == NULL || 3646 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 3647 req->sym_out = req1.sym_out; 3648 req->defobj_out = req1.defobj_out; 3649 assert(req->defobj_out != NULL); 3650 } 3651 } 3652 3653 /* 3654 * Search the dynamic linker itself, and possibly resolve the 3655 * symbol from there. This is how the application links to 3656 * dynamic linker services such as dlopen. 3657 */ 3658 if (req->sym_out == NULL || 3659 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 3660 res = symlook_obj(&req1, &obj_rtld); 3661 if (res == 0) { 3662 req->sym_out = req1.sym_out; 3663 req->defobj_out = req1.defobj_out; 3664 assert(req->defobj_out != NULL); 3665 } 3666 } 3667 3668 return (req->sym_out != NULL ? 0 : ESRCH); 3669} 3670 3671static int 3672symlook_list(SymLook *req, const Objlist *objlist, DoneList *dlp) 3673{ 3674 const Elf_Sym *def; 3675 const Obj_Entry *defobj; 3676 const Objlist_Entry *elm; 3677 SymLook req1; 3678 int res; 3679 3680 def = NULL; 3681 defobj = NULL; 3682 STAILQ_FOREACH(elm, objlist, link) { 3683 if (donelist_check(dlp, elm->obj)) 3684 continue; 3685 symlook_init_from_req(&req1, req); 3686 if ((res = symlook_obj(&req1, elm->obj)) == 0) { 3687 if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) { 3688 def = req1.sym_out; 3689 defobj = req1.defobj_out; 3690 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 3691 break; 3692 } 3693 } 3694 } 3695 if (def != NULL) { 3696 req->sym_out = def; 3697 req->defobj_out = defobj; 3698 return (0); 3699 } 3700 return (ESRCH); 3701} 3702 3703/* 3704 * Search the chain of DAGS cointed to by the given Needed_Entry 3705 * for a symbol of the given name. Each DAG is scanned completely 3706 * before advancing to the next one. Returns a pointer to the symbol, 3707 * or NULL if no definition was found. 3708 */ 3709static int 3710symlook_needed(SymLook *req, const Needed_Entry *needed, DoneList *dlp) 3711{ 3712 const Elf_Sym *def; 3713 const Needed_Entry *n; 3714 const Obj_Entry *defobj; 3715 SymLook req1; 3716 int res; 3717 3718 def = NULL; 3719 defobj = NULL; 3720 symlook_init_from_req(&req1, req); 3721 for (n = needed; n != NULL; n = n->next) { 3722 if (n->obj == NULL || 3723 (res = symlook_list(&req1, &n->obj->dagmembers, dlp)) != 0) 3724 continue; 3725 if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) { 3726 def = req1.sym_out; 3727 defobj = req1.defobj_out; 3728 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 3729 break; 3730 } 3731 } 3732 if (def != NULL) { 3733 req->sym_out = def; 3734 req->defobj_out = defobj; 3735 return (0); 3736 } 3737 return (ESRCH); 3738} 3739 3740/* 3741 * Search the symbol table of a single shared object for a symbol of 3742 * the given name and version, if requested. Returns a pointer to the 3743 * symbol, or NULL if no definition was found. If the object is 3744 * filter, return filtered symbol from filtee. 3745 * 3746 * The symbol's hash value is passed in for efficiency reasons; that 3747 * eliminates many recomputations of the hash value. 3748 */ 3749int 3750symlook_obj(SymLook *req, const Obj_Entry *obj) 3751{ 3752 DoneList donelist; 3753 SymLook req1; 3754 int flags, res, mres; 3755 3756 /* 3757 * If there is at least one valid hash at this point, we prefer to 3758 * use the faster GNU version if available. 3759 */ 3760 if (obj->valid_hash_gnu) 3761 mres = symlook_obj1_gnu(req, obj); 3762 else if (obj->valid_hash_sysv) 3763 mres = symlook_obj1_sysv(req, obj); 3764 else 3765 return (EINVAL); 3766 3767 if (mres == 0) { 3768 if (obj->needed_filtees != NULL) { 3769 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; 3770 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 3771 donelist_init(&donelist); 3772 symlook_init_from_req(&req1, req); 3773 res = symlook_needed(&req1, obj->needed_filtees, &donelist); 3774 if (res == 0) { 3775 req->sym_out = req1.sym_out; 3776 req->defobj_out = req1.defobj_out; 3777 } 3778 return (res); 3779 } 3780 if (obj->needed_aux_filtees != NULL) { 3781 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; 3782 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 3783 donelist_init(&donelist); 3784 symlook_init_from_req(&req1, req); 3785 res = symlook_needed(&req1, obj->needed_aux_filtees, &donelist); 3786 if (res == 0) { 3787 req->sym_out = req1.sym_out; 3788 req->defobj_out = req1.defobj_out; 3789 return (res); 3790 } 3791 } 3792 } 3793 return (mres); 3794} 3795 3796/* Symbol match routine common to both hash functions */ 3797static bool 3798matched_symbol(SymLook *req, const Obj_Entry *obj, Sym_Match_Result *result, 3799 const unsigned long symnum) 3800{ 3801 Elf_Versym verndx; 3802 const Elf_Sym *symp; 3803 const char *strp; 3804 3805 symp = obj->symtab + symnum; 3806 strp = obj->strtab + symp->st_name; 3807 3808 switch (ELF_ST_TYPE(symp->st_info)) { 3809 case STT_FUNC: 3810 case STT_NOTYPE: 3811 case STT_OBJECT: 3812 case STT_COMMON: 3813 case STT_GNU_IFUNC: 3814 if (symp->st_value == 0) 3815 return (false); 3816 /* fallthrough */ 3817 case STT_TLS: 3818 if (symp->st_shndx != SHN_UNDEF) 3819 break; 3820#ifndef __mips__ 3821 else if (((req->flags & SYMLOOK_IN_PLT) == 0) && 3822 (ELF_ST_TYPE(symp->st_info) == STT_FUNC)) 3823 break; 3824 /* fallthrough */ 3825#endif 3826 default: 3827 return (false); 3828 } 3829 if (req->name[0] != strp[0] || strcmp(req->name, strp) != 0) 3830 return (false); 3831 3832 if (req->ventry == NULL) { 3833 if (obj->versyms != NULL) { 3834 verndx = VER_NDX(obj->versyms[symnum]); 3835 if (verndx > obj->vernum) { 3836 _rtld_error( 3837 "%s: symbol %s references wrong version %d", 3838 obj->path, obj->strtab + symnum, verndx); 3839 return (false); 3840 } 3841 /* 3842 * If we are not called from dlsym (i.e. this 3843 * is a normal relocation from unversioned 3844 * binary), accept the symbol immediately if 3845 * it happens to have first version after this 3846 * shared object became versioned. Otherwise, 3847 * if symbol is versioned and not hidden, 3848 * remember it. If it is the only symbol with 3849 * this name exported by the shared object, it 3850 * will be returned as a match by the calling 3851 * function. If symbol is global (verndx < 2) 3852 * accept it unconditionally. 3853 */ 3854 if ((req->flags & SYMLOOK_DLSYM) == 0 && 3855 verndx == VER_NDX_GIVEN) { 3856 result->sym_out = symp; 3857 return (true); 3858 } 3859 else if (verndx >= VER_NDX_GIVEN) { 3860 if ((obj->versyms[symnum] & VER_NDX_HIDDEN) 3861 == 0) { 3862 if (result->vsymp == NULL) 3863 result->vsymp = symp; 3864 result->vcount++; 3865 } 3866 return (false); 3867 } 3868 } 3869 result->sym_out = symp; 3870 return (true); 3871 } 3872 if (obj->versyms == NULL) { 3873 if (object_match_name(obj, req->ventry->name)) { 3874 _rtld_error("%s: object %s should provide version %s " 3875 "for symbol %s", obj_rtld.path, obj->path, 3876 req->ventry->name, obj->strtab + symnum); 3877 return (false); 3878 } 3879 } else { 3880 verndx = VER_NDX(obj->versyms[symnum]); 3881 if (verndx > obj->vernum) { 3882 _rtld_error("%s: symbol %s references wrong version %d", 3883 obj->path, obj->strtab + symnum, verndx); 3884 return (false); 3885 } 3886 if (obj->vertab[verndx].hash != req->ventry->hash || 3887 strcmp(obj->vertab[verndx].name, req->ventry->name)) { 3888 /* 3889 * Version does not match. Look if this is a 3890 * global symbol and if it is not hidden. If 3891 * global symbol (verndx < 2) is available, 3892 * use it. Do not return symbol if we are 3893 * called by dlvsym, because dlvsym looks for 3894 * a specific version and default one is not 3895 * what dlvsym wants. 3896 */ 3897 if ((req->flags & SYMLOOK_DLSYM) || 3898 (verndx >= VER_NDX_GIVEN) || 3899 (obj->versyms[symnum] & VER_NDX_HIDDEN)) 3900 return (false); 3901 } 3902 } 3903 result->sym_out = symp; 3904 return (true); 3905} 3906 3907/* 3908 * Search for symbol using SysV hash function. 3909 * obj->buckets is known not to be NULL at this point; the test for this was 3910 * performed with the obj->valid_hash_sysv assignment. 3911 */ 3912static int 3913symlook_obj1_sysv(SymLook *req, const Obj_Entry *obj) 3914{ 3915 unsigned long symnum; 3916 Sym_Match_Result matchres; 3917 3918 matchres.sym_out = NULL; 3919 matchres.vsymp = NULL; 3920 matchres.vcount = 0; 3921 3922 for (symnum = obj->buckets[req->hash % obj->nbuckets]; 3923 symnum != STN_UNDEF; symnum = obj->chains[symnum]) { 3924 if (symnum >= obj->nchains) 3925 return (ESRCH); /* Bad object */ 3926 3927 if (matched_symbol(req, obj, &matchres, symnum)) { 3928 req->sym_out = matchres.sym_out; 3929 req->defobj_out = obj; 3930 return (0); 3931 } 3932 } 3933 if (matchres.vcount == 1) { 3934 req->sym_out = matchres.vsymp; 3935 req->defobj_out = obj; 3936 return (0); 3937 } 3938 return (ESRCH); 3939} 3940 3941/* Search for symbol using GNU hash function */ 3942static int 3943symlook_obj1_gnu(SymLook *req, const Obj_Entry *obj) 3944{ 3945 Elf_Addr bloom_word; 3946 const Elf32_Word *hashval; 3947 Elf32_Word bucket; 3948 Sym_Match_Result matchres; 3949 unsigned int h1, h2; 3950 unsigned long symnum; 3951 3952 matchres.sym_out = NULL; 3953 matchres.vsymp = NULL; 3954 matchres.vcount = 0; 3955 3956 /* Pick right bitmask word from Bloom filter array */ 3957 bloom_word = obj->bloom_gnu[(req->hash_gnu / __ELF_WORD_SIZE) & 3958 obj->maskwords_bm_gnu]; 3959 3960 /* Calculate modulus word size of gnu hash and its derivative */ 3961 h1 = req->hash_gnu & (__ELF_WORD_SIZE - 1); 3962 h2 = ((req->hash_gnu >> obj->shift2_gnu) & (__ELF_WORD_SIZE - 1)); 3963 3964 /* Filter out the "definitely not in set" queries */ 3965 if (((bloom_word >> h1) & (bloom_word >> h2) & 1) == 0) 3966 return (ESRCH); 3967 3968 /* Locate hash chain and corresponding value element*/ 3969 bucket = obj->buckets_gnu[req->hash_gnu % obj->nbuckets_gnu]; 3970 if (bucket == 0) 3971 return (ESRCH); 3972 hashval = &obj->chain_zero_gnu[bucket]; 3973 do { 3974 if (((*hashval ^ req->hash_gnu) >> 1) == 0) { 3975 symnum = hashval - obj->chain_zero_gnu; 3976 if (matched_symbol(req, obj, &matchres, symnum)) { 3977 req->sym_out = matchres.sym_out; 3978 req->defobj_out = obj; 3979 return (0); 3980 } 3981 } 3982 } while ((*hashval++ & 1) == 0); 3983 if (matchres.vcount == 1) { 3984 req->sym_out = matchres.vsymp; 3985 req->defobj_out = obj; 3986 return (0); 3987 } 3988 return (ESRCH); 3989} 3990 3991static void 3992trace_loaded_objects(Obj_Entry *obj) 3993{ 3994 char *fmt1, *fmt2, *fmt, *main_local, *list_containers; 3995 int c; 3996 3997 if ((main_local = getenv(LD_ "TRACE_LOADED_OBJECTS_PROGNAME")) == NULL) 3998 main_local = ""; 3999 4000 if ((fmt1 = getenv(LD_ "TRACE_LOADED_OBJECTS_FMT1")) == NULL) 4001 fmt1 = "\t%o => %p (%x)\n"; 4002 4003 if ((fmt2 = getenv(LD_ "TRACE_LOADED_OBJECTS_FMT2")) == NULL) 4004 fmt2 = "\t%o (%x)\n"; 4005 4006 list_containers = getenv(LD_ "TRACE_LOADED_OBJECTS_ALL"); 4007 4008 for (; obj; obj = obj->next) { 4009 Needed_Entry *needed; 4010 char *name, *path; 4011 bool is_lib; 4012 4013 if (list_containers && obj->needed != NULL) 4014 rtld_printf("%s:\n", obj->path); 4015 for (needed = obj->needed; needed; needed = needed->next) { 4016 if (needed->obj != NULL) { 4017 if (needed->obj->traced && !list_containers) 4018 continue; 4019 needed->obj->traced = true; 4020 path = needed->obj->path; 4021 } else 4022 path = "not found"; 4023 4024 name = (char *)obj->strtab + needed->name; 4025 is_lib = strncmp(name, "lib", 3) == 0; /* XXX - bogus */ 4026 4027 fmt = is_lib ? fmt1 : fmt2; 4028 while ((c = *fmt++) != '\0') { 4029 switch (c) { 4030 default: 4031 rtld_putchar(c); 4032 continue; 4033 case '\\': 4034 switch (c = *fmt) { 4035 case '\0': 4036 continue; 4037 case 'n': 4038 rtld_putchar('\n'); 4039 break; 4040 case 't': 4041 rtld_putchar('\t'); 4042 break; 4043 } 4044 break; 4045 case '%': 4046 switch (c = *fmt) { 4047 case '\0': 4048 continue; 4049 case '%': 4050 default: 4051 rtld_putchar(c); 4052 break; 4053 case 'A': 4054 rtld_putstr(main_local); 4055 break; 4056 case 'a': 4057 rtld_putstr(obj_main->path); 4058 break; 4059 case 'o': 4060 rtld_putstr(name); 4061 break; 4062#if 0 4063 case 'm': 4064 rtld_printf("%d", sodp->sod_major); 4065 break; 4066 case 'n': 4067 rtld_printf("%d", sodp->sod_minor); 4068 break; 4069#endif 4070 case 'p': 4071 rtld_putstr(path); 4072 break; 4073 case 'x': 4074 rtld_printf("%p", needed->obj ? needed->obj->mapbase : 4075 0); 4076 break; 4077 } 4078 break; 4079 } 4080 ++fmt; 4081 } 4082 } 4083 } 4084} 4085 4086/* 4087 * Unload a dlopened object and its dependencies from memory and from 4088 * our data structures. It is assumed that the DAG rooted in the 4089 * object has already been unreferenced, and that the object has a 4090 * reference count of 0. 4091 */ 4092static void 4093unload_object(Obj_Entry *root) 4094{ 4095 Obj_Entry *obj; 4096 Obj_Entry **linkp; 4097 4098 assert(root->refcount == 0); 4099 4100 /* 4101 * Pass over the DAG removing unreferenced objects from 4102 * appropriate lists. 4103 */ 4104 unlink_object(root); 4105 4106 /* Unmap all objects that are no longer referenced. */ 4107 linkp = &obj_list->next; 4108 while ((obj = *linkp) != NULL) { 4109 if (obj->refcount == 0) { 4110 LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 4111 obj->path); 4112 dbg("unloading \"%s\"", obj->path); 4113 unload_filtees(root); 4114 munmap(obj->mapbase, obj->mapsize); 4115 linkmap_delete(obj); 4116 *linkp = obj->next; 4117 obj_count--; 4118 obj_free(obj); 4119 } else 4120 linkp = &obj->next; 4121 } 4122 obj_tail = linkp; 4123} 4124 4125static void 4126unlink_object(Obj_Entry *root) 4127{ 4128 Objlist_Entry *elm; 4129 4130 if (root->refcount == 0) { 4131 /* Remove the object from the RTLD_GLOBAL list. */ 4132 objlist_remove(&list_global, root); 4133 4134 /* Remove the object from all objects' DAG lists. */ 4135 STAILQ_FOREACH(elm, &root->dagmembers, link) { 4136 objlist_remove(&elm->obj->dldags, root); 4137 if (elm->obj != root) 4138 unlink_object(elm->obj); 4139 } 4140 } 4141} 4142 4143static void 4144ref_dag(Obj_Entry *root) 4145{ 4146 Objlist_Entry *elm; 4147 4148 assert(root->dag_inited); 4149 STAILQ_FOREACH(elm, &root->dagmembers, link) 4150 elm->obj->refcount++; 4151} 4152 4153static void 4154unref_dag(Obj_Entry *root) 4155{ 4156 Objlist_Entry *elm; 4157 4158 assert(root->dag_inited); 4159 STAILQ_FOREACH(elm, &root->dagmembers, link) 4160 elm->obj->refcount--; 4161} 4162 4163/* 4164 * Common code for MD __tls_get_addr(). 4165 */ 4166static void *tls_get_addr_slow(Elf_Addr **, int, size_t) __noinline; 4167static void * 4168tls_get_addr_slow(Elf_Addr **dtvp, int index, size_t offset) 4169{ 4170 Elf_Addr *newdtv, *dtv; 4171 RtldLockState lockstate; 4172 int to_copy; 4173 4174 dtv = *dtvp; 4175 /* Check dtv generation in case new modules have arrived */ 4176 if (dtv[0] != tls_dtv_generation) { 4177 wlock_acquire(rtld_bind_lock, &lockstate); 4178 newdtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4179 to_copy = dtv[1]; 4180 if (to_copy > tls_max_index) 4181 to_copy = tls_max_index; 4182 memcpy(&newdtv[2], &dtv[2], to_copy * sizeof(Elf_Addr)); 4183 newdtv[0] = tls_dtv_generation; 4184 newdtv[1] = tls_max_index; 4185 free(dtv); 4186 lock_release(rtld_bind_lock, &lockstate); 4187 dtv = *dtvp = newdtv; 4188 } 4189 4190 /* Dynamically allocate module TLS if necessary */ 4191 if (dtv[index + 1] == 0) { 4192 /* Signal safe, wlock will block out signals. */ 4193 wlock_acquire(rtld_bind_lock, &lockstate); 4194 if (!dtv[index + 1]) 4195 dtv[index + 1] = (Elf_Addr)allocate_module_tls(index); 4196 lock_release(rtld_bind_lock, &lockstate); 4197 } 4198 return ((void *)(dtv[index + 1] + offset)); 4199} 4200 4201void * 4202tls_get_addr_common(Elf_Addr **dtvp, int index, size_t offset) 4203{ 4204 Elf_Addr *dtv; 4205 4206 dtv = *dtvp; 4207 /* Check dtv generation in case new modules have arrived */ 4208 if (__predict_true(dtv[0] == tls_dtv_generation && 4209 dtv[index + 1] != 0)) 4210 return ((void *)(dtv[index + 1] + offset)); 4211 return (tls_get_addr_slow(dtvp, index, offset)); 4212} 4213 4214#if defined(__arm__) || defined(__ia64__) || defined(__mips__) || defined(__powerpc__) 4215 4216/* 4217 * Allocate Static TLS using the Variant I method. 4218 */ 4219void * 4220allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign) 4221{ 4222 Obj_Entry *obj; 4223 char *tcb; 4224 Elf_Addr **tls; 4225 Elf_Addr *dtv; 4226 Elf_Addr addr; 4227 int i; 4228 4229 if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE) 4230 return (oldtcb); 4231 4232 assert(tcbsize >= TLS_TCB_SIZE); 4233 tcb = xcalloc(1, tls_static_space - TLS_TCB_SIZE + tcbsize); 4234 tls = (Elf_Addr **)(tcb + tcbsize - TLS_TCB_SIZE); 4235 4236 if (oldtcb != NULL) { 4237 memcpy(tls, oldtcb, tls_static_space); 4238 free(oldtcb); 4239 4240 /* Adjust the DTV. */ 4241 dtv = tls[0]; 4242 for (i = 0; i < dtv[1]; i++) { 4243 if (dtv[i+2] >= (Elf_Addr)oldtcb && 4244 dtv[i+2] < (Elf_Addr)oldtcb + tls_static_space) { 4245 dtv[i+2] = dtv[i+2] - (Elf_Addr)oldtcb + (Elf_Addr)tls; 4246 } 4247 } 4248 } else { 4249 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4250 tls[0] = dtv; 4251 dtv[0] = tls_dtv_generation; 4252 dtv[1] = tls_max_index; 4253 4254 for (obj = objs; obj; obj = obj->next) { 4255 if (obj->tlsoffset > 0) { 4256 addr = (Elf_Addr)tls + obj->tlsoffset; 4257 if (obj->tlsinitsize > 0) 4258 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize); 4259 if (obj->tlssize > obj->tlsinitsize) 4260 memset((void*) (addr + obj->tlsinitsize), 0, 4261 obj->tlssize - obj->tlsinitsize); 4262 dtv[obj->tlsindex + 1] = addr; 4263 } 4264 } 4265 } 4266 4267 return (tcb); 4268} 4269 4270void 4271free_tls(void *tcb, size_t tcbsize, size_t tcbalign) 4272{ 4273 Elf_Addr *dtv; 4274 Elf_Addr tlsstart, tlsend; 4275 int dtvsize, i; 4276 4277 assert(tcbsize >= TLS_TCB_SIZE); 4278 4279 tlsstart = (Elf_Addr)tcb + tcbsize - TLS_TCB_SIZE; 4280 tlsend = tlsstart + tls_static_space; 4281 4282 dtv = *(Elf_Addr **)tlsstart; 4283 dtvsize = dtv[1]; 4284 for (i = 0; i < dtvsize; i++) { 4285 if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] >= tlsend)) { 4286 free((void*)dtv[i+2]); 4287 } 4288 } 4289 free(dtv); 4290 free(tcb); 4291} 4292 4293#endif 4294 4295#if defined(__i386__) || defined(__amd64__) || defined(__sparc64__) 4296 4297/* 4298 * Allocate Static TLS using the Variant II method. 4299 */ 4300void * 4301allocate_tls(Obj_Entry *objs, void *oldtls, size_t tcbsize, size_t tcbalign) 4302{ 4303 Obj_Entry *obj; 4304 size_t size, ralign; 4305 char *tls; 4306 Elf_Addr *dtv, *olddtv; 4307 Elf_Addr segbase, oldsegbase, addr; 4308 int i; 4309 4310 ralign = tcbalign; 4311 if (tls_static_max_align > ralign) 4312 ralign = tls_static_max_align; 4313 size = round(tls_static_space, ralign) + round(tcbsize, ralign); 4314 4315 assert(tcbsize >= 2*sizeof(Elf_Addr)); 4316 tls = malloc_aligned(size, ralign); 4317 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4318 4319 segbase = (Elf_Addr)(tls + round(tls_static_space, ralign)); 4320 ((Elf_Addr*)segbase)[0] = segbase; 4321 ((Elf_Addr*)segbase)[1] = (Elf_Addr) dtv; 4322 4323 dtv[0] = tls_dtv_generation; 4324 dtv[1] = tls_max_index; 4325 4326 if (oldtls) { 4327 /* 4328 * Copy the static TLS block over whole. 4329 */ 4330 oldsegbase = (Elf_Addr) oldtls; 4331 memcpy((void *)(segbase - tls_static_space), 4332 (const void *)(oldsegbase - tls_static_space), 4333 tls_static_space); 4334 4335 /* 4336 * If any dynamic TLS blocks have been created tls_get_addr(), 4337 * move them over. 4338 */ 4339 olddtv = ((Elf_Addr**)oldsegbase)[1]; 4340 for (i = 0; i < olddtv[1]; i++) { 4341 if (olddtv[i+2] < oldsegbase - size || olddtv[i+2] > oldsegbase) { 4342 dtv[i+2] = olddtv[i+2]; 4343 olddtv[i+2] = 0; 4344 } 4345 } 4346 4347 /* 4348 * We assume that this block was the one we created with 4349 * allocate_initial_tls(). 4350 */ 4351 free_tls(oldtls, 2*sizeof(Elf_Addr), sizeof(Elf_Addr)); 4352 } else { 4353 for (obj = objs; obj; obj = obj->next) { 4354 if (obj->tlsoffset) { 4355 addr = segbase - obj->tlsoffset; 4356 memset((void*) (addr + obj->tlsinitsize), 4357 0, obj->tlssize - obj->tlsinitsize); 4358 if (obj->tlsinit) 4359 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize); 4360 dtv[obj->tlsindex + 1] = addr; 4361 } 4362 } 4363 } 4364 4365 return (void*) segbase; 4366} 4367 4368void 4369free_tls(void *tls, size_t tcbsize, size_t tcbalign) 4370{ 4371 Elf_Addr* dtv; 4372 size_t size, ralign; 4373 int dtvsize, i; 4374 Elf_Addr tlsstart, tlsend; 4375 4376 /* 4377 * Figure out the size of the initial TLS block so that we can 4378 * find stuff which ___tls_get_addr() allocated dynamically. 4379 */ 4380 ralign = tcbalign; 4381 if (tls_static_max_align > ralign) 4382 ralign = tls_static_max_align; 4383 size = round(tls_static_space, ralign); 4384 4385 dtv = ((Elf_Addr**)tls)[1]; 4386 dtvsize = dtv[1]; 4387 tlsend = (Elf_Addr) tls; 4388 tlsstart = tlsend - size; 4389 for (i = 0; i < dtvsize; i++) { 4390 if (dtv[i + 2] != 0 && (dtv[i + 2] < tlsstart || dtv[i + 2] > tlsend)) { 4391 free_aligned((void *)dtv[i + 2]); 4392 } 4393 } 4394 4395 free_aligned((void *)tlsstart); 4396 free((void*) dtv); 4397} 4398 4399#endif 4400 4401/* 4402 * Allocate TLS block for module with given index. 4403 */ 4404void * 4405allocate_module_tls(int index) 4406{ 4407 Obj_Entry* obj; 4408 char* p; 4409 4410 for (obj = obj_list; obj; obj = obj->next) { 4411 if (obj->tlsindex == index) 4412 break; 4413 } 4414 if (!obj) { 4415 _rtld_error("Can't find module with TLS index %d", index); 4416 die(); 4417 } 4418 4419 p = malloc_aligned(obj->tlssize, obj->tlsalign); 4420 memcpy(p, obj->tlsinit, obj->tlsinitsize); 4421 memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize); 4422 4423 return p; 4424} 4425 4426bool 4427allocate_tls_offset(Obj_Entry *obj) 4428{ 4429 size_t off; 4430 4431 if (obj->tls_done) 4432 return true; 4433 4434 if (obj->tlssize == 0) { 4435 obj->tls_done = true; 4436 return true; 4437 } 4438 4439 if (obj->tlsindex == 1) 4440 off = calculate_first_tls_offset(obj->tlssize, obj->tlsalign); 4441 else 4442 off = calculate_tls_offset(tls_last_offset, tls_last_size, 4443 obj->tlssize, obj->tlsalign); 4444 4445 /* 4446 * If we have already fixed the size of the static TLS block, we 4447 * must stay within that size. When allocating the static TLS, we 4448 * leave a small amount of space spare to be used for dynamically 4449 * loading modules which use static TLS. 4450 */ 4451 if (tls_static_space != 0) { 4452 if (calculate_tls_end(off, obj->tlssize) > tls_static_space) 4453 return false; 4454 } else if (obj->tlsalign > tls_static_max_align) { 4455 tls_static_max_align = obj->tlsalign; 4456 } 4457 4458 tls_last_offset = obj->tlsoffset = off; 4459 tls_last_size = obj->tlssize; 4460 obj->tls_done = true; 4461 4462 return true; 4463} 4464 4465void 4466free_tls_offset(Obj_Entry *obj) 4467{ 4468 4469 /* 4470 * If we were the last thing to allocate out of the static TLS 4471 * block, we give our space back to the 'allocator'. This is a 4472 * simplistic workaround to allow libGL.so.1 to be loaded and 4473 * unloaded multiple times. 4474 */ 4475 if (calculate_tls_end(obj->tlsoffset, obj->tlssize) 4476 == calculate_tls_end(tls_last_offset, tls_last_size)) { 4477 tls_last_offset -= obj->tlssize; 4478 tls_last_size = 0; 4479 } 4480} 4481 4482void * 4483_rtld_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign) 4484{ 4485 void *ret; 4486 RtldLockState lockstate; 4487 4488 wlock_acquire(rtld_bind_lock, &lockstate); 4489 ret = allocate_tls(obj_list, oldtls, tcbsize, tcbalign); 4490 lock_release(rtld_bind_lock, &lockstate); 4491 return (ret); 4492} 4493 4494void 4495_rtld_free_tls(void *tcb, size_t tcbsize, size_t tcbalign) 4496{ 4497 RtldLockState lockstate; 4498 4499 wlock_acquire(rtld_bind_lock, &lockstate); 4500 free_tls(tcb, tcbsize, tcbalign); 4501 lock_release(rtld_bind_lock, &lockstate); 4502} 4503 4504static void 4505object_add_name(Obj_Entry *obj, const char *name) 4506{ 4507 Name_Entry *entry; 4508 size_t len; 4509 4510 len = strlen(name); 4511 entry = malloc(sizeof(Name_Entry) + len); 4512 4513 if (entry != NULL) { 4514 strcpy(entry->name, name); 4515 STAILQ_INSERT_TAIL(&obj->names, entry, link); 4516 } 4517} 4518 4519static int 4520object_match_name(const Obj_Entry *obj, const char *name) 4521{ 4522 Name_Entry *entry; 4523 4524 STAILQ_FOREACH(entry, &obj->names, link) { 4525 if (strcmp(name, entry->name) == 0) 4526 return (1); 4527 } 4528 return (0); 4529} 4530 4531static Obj_Entry * 4532locate_dependency(const Obj_Entry *obj, const char *name) 4533{ 4534 const Objlist_Entry *entry; 4535 const Needed_Entry *needed; 4536 4537 STAILQ_FOREACH(entry, &list_main, link) { 4538 if (object_match_name(entry->obj, name)) 4539 return entry->obj; 4540 } 4541 4542 for (needed = obj->needed; needed != NULL; needed = needed->next) { 4543 if (strcmp(obj->strtab + needed->name, name) == 0 || 4544 (needed->obj != NULL && object_match_name(needed->obj, name))) { 4545 /* 4546 * If there is DT_NEEDED for the name we are looking for, 4547 * we are all set. Note that object might not be found if 4548 * dependency was not loaded yet, so the function can 4549 * return NULL here. This is expected and handled 4550 * properly by the caller. 4551 */ 4552 return (needed->obj); 4553 } 4554 } 4555 _rtld_error("%s: Unexpected inconsistency: dependency %s not found", 4556 obj->path, name); 4557 die(); 4558} 4559 4560static int 4561check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj, 4562 const Elf_Vernaux *vna) 4563{ 4564 const Elf_Verdef *vd; 4565 const char *vername; 4566 4567 vername = refobj->strtab + vna->vna_name; 4568 vd = depobj->verdef; 4569 if (vd == NULL) { 4570 _rtld_error("%s: version %s required by %s not defined", 4571 depobj->path, vername, refobj->path); 4572 return (-1); 4573 } 4574 for (;;) { 4575 if (vd->vd_version != VER_DEF_CURRENT) { 4576 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 4577 depobj->path, vd->vd_version); 4578 return (-1); 4579 } 4580 if (vna->vna_hash == vd->vd_hash) { 4581 const Elf_Verdaux *aux = (const Elf_Verdaux *) 4582 ((char *)vd + vd->vd_aux); 4583 if (strcmp(vername, depobj->strtab + aux->vda_name) == 0) 4584 return (0); 4585 } 4586 if (vd->vd_next == 0) 4587 break; 4588 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next); 4589 } 4590 if (vna->vna_flags & VER_FLG_WEAK) 4591 return (0); 4592 _rtld_error("%s: version %s required by %s not found", 4593 depobj->path, vername, refobj->path); 4594 return (-1); 4595} 4596 4597static int 4598rtld_verify_object_versions(Obj_Entry *obj) 4599{ 4600 const Elf_Verneed *vn; 4601 const Elf_Verdef *vd; 4602 const Elf_Verdaux *vda; 4603 const Elf_Vernaux *vna; 4604 const Obj_Entry *depobj; 4605 int maxvernum, vernum; 4606 4607 if (obj->ver_checked) 4608 return (0); 4609 obj->ver_checked = true; 4610 4611 maxvernum = 0; 4612 /* 4613 * Walk over defined and required version records and figure out 4614 * max index used by any of them. Do very basic sanity checking 4615 * while there. 4616 */ 4617 vn = obj->verneed; 4618 while (vn != NULL) { 4619 if (vn->vn_version != VER_NEED_CURRENT) { 4620 _rtld_error("%s: Unsupported version %d of Elf_Verneed entry", 4621 obj->path, vn->vn_version); 4622 return (-1); 4623 } 4624 vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux); 4625 for (;;) { 4626 vernum = VER_NEED_IDX(vna->vna_other); 4627 if (vernum > maxvernum) 4628 maxvernum = vernum; 4629 if (vna->vna_next == 0) 4630 break; 4631 vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next); 4632 } 4633 if (vn->vn_next == 0) 4634 break; 4635 vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next); 4636 } 4637 4638 vd = obj->verdef; 4639 while (vd != NULL) { 4640 if (vd->vd_version != VER_DEF_CURRENT) { 4641 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 4642 obj->path, vd->vd_version); 4643 return (-1); 4644 } 4645 vernum = VER_DEF_IDX(vd->vd_ndx); 4646 if (vernum > maxvernum) 4647 maxvernum = vernum; 4648 if (vd->vd_next == 0) 4649 break; 4650 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next); 4651 } 4652 4653 if (maxvernum == 0) 4654 return (0); 4655 4656 /* 4657 * Store version information in array indexable by version index. 4658 * Verify that object version requirements are satisfied along the 4659 * way. 4660 */ 4661 obj->vernum = maxvernum + 1; 4662 obj->vertab = xcalloc(obj->vernum, sizeof(Ver_Entry)); 4663 4664 vd = obj->verdef; 4665 while (vd != NULL) { 4666 if ((vd->vd_flags & VER_FLG_BASE) == 0) { 4667 vernum = VER_DEF_IDX(vd->vd_ndx); 4668 assert(vernum <= maxvernum); 4669 vda = (const Elf_Verdaux *)((char *)vd + vd->vd_aux); 4670 obj->vertab[vernum].hash = vd->vd_hash; 4671 obj->vertab[vernum].name = obj->strtab + vda->vda_name; 4672 obj->vertab[vernum].file = NULL; 4673 obj->vertab[vernum].flags = 0; 4674 } 4675 if (vd->vd_next == 0) 4676 break; 4677 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next); 4678 } 4679 4680 vn = obj->verneed; 4681 while (vn != NULL) { 4682 depobj = locate_dependency(obj, obj->strtab + vn->vn_file); 4683 if (depobj == NULL) 4684 return (-1); 4685 vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux); 4686 for (;;) { 4687 if (check_object_provided_version(obj, depobj, vna)) 4688 return (-1); 4689 vernum = VER_NEED_IDX(vna->vna_other); 4690 assert(vernum <= maxvernum); 4691 obj->vertab[vernum].hash = vna->vna_hash; 4692 obj->vertab[vernum].name = obj->strtab + vna->vna_name; 4693 obj->vertab[vernum].file = obj->strtab + vn->vn_file; 4694 obj->vertab[vernum].flags = (vna->vna_other & VER_NEED_HIDDEN) ? 4695 VER_INFO_HIDDEN : 0; 4696 if (vna->vna_next == 0) 4697 break; 4698 vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next); 4699 } 4700 if (vn->vn_next == 0) 4701 break; 4702 vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next); 4703 } 4704 return 0; 4705} 4706 4707static int 4708rtld_verify_versions(const Objlist *objlist) 4709{ 4710 Objlist_Entry *entry; 4711 int rc; 4712 4713 rc = 0; 4714 STAILQ_FOREACH(entry, objlist, link) { 4715 /* 4716 * Skip dummy objects or objects that have their version requirements 4717 * already checked. 4718 */ 4719 if (entry->obj->strtab == NULL || entry->obj->vertab != NULL) 4720 continue; 4721 if (rtld_verify_object_versions(entry->obj) == -1) { 4722 rc = -1; 4723 if (ld_tracing == NULL) 4724 break; 4725 } 4726 } 4727 if (rc == 0 || ld_tracing != NULL) 4728 rc = rtld_verify_object_versions(&obj_rtld); 4729 return rc; 4730} 4731 4732const Ver_Entry * 4733fetch_ventry(const Obj_Entry *obj, unsigned long symnum) 4734{ 4735 Elf_Versym vernum; 4736 4737 if (obj->vertab) { 4738 vernum = VER_NDX(obj->versyms[symnum]); 4739 if (vernum >= obj->vernum) { 4740 _rtld_error("%s: symbol %s has wrong verneed value %d", 4741 obj->path, obj->strtab + symnum, vernum); 4742 } else if (obj->vertab[vernum].hash != 0) { 4743 return &obj->vertab[vernum]; 4744 } 4745 } 4746 return NULL; 4747} 4748 4749int 4750_rtld_get_stack_prot(void) 4751{ 4752 4753 return (stack_prot); 4754} 4755 4756int 4757_rtld_is_dlopened(void *arg) 4758{ 4759 Obj_Entry *obj; 4760 RtldLockState lockstate; 4761 int res; 4762 4763 rlock_acquire(rtld_bind_lock, &lockstate); 4764 obj = dlcheck(arg); 4765 if (obj == NULL) 4766 obj = obj_from_addr(arg); 4767 if (obj == NULL) { 4768 _rtld_error("No shared object contains address"); 4769 lock_release(rtld_bind_lock, &lockstate); 4770 return (-1); 4771 } 4772 res = obj->dlopened ? 1 : 0; 4773 lock_release(rtld_bind_lock, &lockstate); 4774 return (res); 4775} 4776 4777static void 4778map_stacks_exec(RtldLockState *lockstate) 4779{ 4780 void (*thr_map_stacks_exec)(void); 4781 4782 if ((max_stack_flags & PF_X) == 0 || (stack_prot & PROT_EXEC) != 0) 4783 return; 4784 thr_map_stacks_exec = (void (*)(void))(uintptr_t) 4785 get_program_var_addr("__pthread_map_stacks_exec", lockstate); 4786 if (thr_map_stacks_exec != NULL) { 4787 stack_prot |= PROT_EXEC; 4788 thr_map_stacks_exec(); 4789 } 4790} 4791 4792void 4793symlook_init(SymLook *dst, const char *name) 4794{ 4795 4796 bzero(dst, sizeof(*dst)); 4797 dst->name = name; 4798 dst->hash = elf_hash(name); 4799 dst->hash_gnu = gnu_hash(name); 4800} 4801 4802static void 4803symlook_init_from_req(SymLook *dst, const SymLook *src) 4804{ 4805 4806 dst->name = src->name; 4807 dst->hash = src->hash; 4808 dst->hash_gnu = src->hash_gnu; 4809 dst->ventry = src->ventry; 4810 dst->flags = src->flags; 4811 dst->defobj_out = NULL; 4812 dst->sym_out = NULL; 4813 dst->lockstate = src->lockstate; 4814} 4815 4816/* 4817 * Overrides for libc_pic-provided functions. 4818 */ 4819 4820int 4821__getosreldate(void) 4822{ 4823 size_t len; 4824 int oid[2]; 4825 int error, osrel; 4826 4827 if (osreldate != 0) 4828 return (osreldate); 4829 4830 oid[0] = CTL_KERN; 4831 oid[1] = KERN_OSRELDATE; 4832 osrel = 0; 4833 len = sizeof(osrel); 4834 error = sysctl(oid, 2, &osrel, &len, NULL, 0); 4835 if (error == 0 && osrel > 0 && len == sizeof(osrel)) 4836 osreldate = osrel; 4837 return (osreldate); 4838} 4839 4840void 4841exit(int status) 4842{ 4843 4844 _exit(status); 4845} 4846 4847void (*__cleanup)(void); 4848int __isthreaded = 0; 4849int _thread_autoinit_dummy_decl = 1; 4850 4851/* 4852 * No unresolved symbols for rtld. 4853 */ 4854void 4855__pthread_cxa_finalize(struct dl_phdr_info *a) 4856{ 4857} 4858 4859void 4860__stack_chk_fail(void) 4861{ 4862 4863 _rtld_error("stack overflow detected; terminated"); 4864 die(); 4865} 4866__weak_reference(__stack_chk_fail, __stack_chk_fail_local); 4867 4868void 4869__chk_fail(void) 4870{ 4871 4872 _rtld_error("buffer overflow detected; terminated"); 4873 die(); 4874} 4875 4876const char * 4877rtld_strerror(int errnum) 4878{ 4879 4880 if (errnum < 0 || errnum >= sys_nerr) 4881 return ("Unknown error"); 4882 return (sys_errlist[errnum]); 4883} 4884