rtld.c revision 278309
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 278309 2015-02-06 08:58:06Z 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 int plttype = DT_REL; 867 868 *dyn_rpath = NULL; 869 *dyn_soname = NULL; 870 *dyn_runpath = NULL; 871 872 obj->bind_now = false; 873 for (dynp = obj->dynamic; dynp->d_tag != DT_NULL; dynp++) { 874 switch (dynp->d_tag) { 875 876 case DT_REL: 877 obj->rel = (const Elf_Rel *) (obj->relocbase + dynp->d_un.d_ptr); 878 break; 879 880 case DT_RELSZ: 881 obj->relsize = dynp->d_un.d_val; 882 break; 883 884 case DT_RELENT: 885 assert(dynp->d_un.d_val == sizeof(Elf_Rel)); 886 break; 887 888 case DT_JMPREL: 889 obj->pltrel = (const Elf_Rel *) 890 (obj->relocbase + dynp->d_un.d_ptr); 891 break; 892 893 case DT_PLTRELSZ: 894 obj->pltrelsize = dynp->d_un.d_val; 895 break; 896 897 case DT_RELA: 898 obj->rela = (const Elf_Rela *) (obj->relocbase + dynp->d_un.d_ptr); 899 break; 900 901 case DT_RELASZ: 902 obj->relasize = dynp->d_un.d_val; 903 break; 904 905 case DT_RELAENT: 906 assert(dynp->d_un.d_val == sizeof(Elf_Rela)); 907 break; 908 909 case DT_PLTREL: 910 plttype = dynp->d_un.d_val; 911 assert(dynp->d_un.d_val == DT_REL || plttype == DT_RELA); 912 break; 913 914 case DT_SYMTAB: 915 obj->symtab = (const Elf_Sym *) 916 (obj->relocbase + dynp->d_un.d_ptr); 917 break; 918 919 case DT_SYMENT: 920 assert(dynp->d_un.d_val == sizeof(Elf_Sym)); 921 break; 922 923 case DT_STRTAB: 924 obj->strtab = (const char *) (obj->relocbase + dynp->d_un.d_ptr); 925 break; 926 927 case DT_STRSZ: 928 obj->strsize = dynp->d_un.d_val; 929 break; 930 931 case DT_VERNEED: 932 obj->verneed = (const Elf_Verneed *) (obj->relocbase + 933 dynp->d_un.d_val); 934 break; 935 936 case DT_VERNEEDNUM: 937 obj->verneednum = dynp->d_un.d_val; 938 break; 939 940 case DT_VERDEF: 941 obj->verdef = (const Elf_Verdef *) (obj->relocbase + 942 dynp->d_un.d_val); 943 break; 944 945 case DT_VERDEFNUM: 946 obj->verdefnum = dynp->d_un.d_val; 947 break; 948 949 case DT_VERSYM: 950 obj->versyms = (const Elf_Versym *)(obj->relocbase + 951 dynp->d_un.d_val); 952 break; 953 954 case DT_HASH: 955 { 956 hashtab = (const Elf_Hashelt *)(obj->relocbase + 957 dynp->d_un.d_ptr); 958 obj->nbuckets = hashtab[0]; 959 obj->nchains = hashtab[1]; 960 obj->buckets = hashtab + 2; 961 obj->chains = obj->buckets + obj->nbuckets; 962 obj->valid_hash_sysv = obj->nbuckets > 0 && obj->nchains > 0 && 963 obj->buckets != NULL; 964 } 965 break; 966 967 case DT_GNU_HASH: 968 { 969 hashtab = (const Elf_Hashelt *)(obj->relocbase + 970 dynp->d_un.d_ptr); 971 obj->nbuckets_gnu = hashtab[0]; 972 obj->symndx_gnu = hashtab[1]; 973 nmaskwords = hashtab[2]; 974 bloom_size32 = (__ELF_WORD_SIZE / 32) * nmaskwords; 975 obj->maskwords_bm_gnu = nmaskwords - 1; 976 obj->shift2_gnu = hashtab[3]; 977 obj->bloom_gnu = (Elf_Addr *) (hashtab + 4); 978 obj->buckets_gnu = hashtab + 4 + bloom_size32; 979 obj->chain_zero_gnu = obj->buckets_gnu + obj->nbuckets_gnu - 980 obj->symndx_gnu; 981 /* Number of bitmask words is required to be power of 2 */ 982 obj->valid_hash_gnu = powerof2(nmaskwords) && 983 obj->nbuckets_gnu > 0 && obj->buckets_gnu != NULL; 984 } 985 break; 986 987 case DT_NEEDED: 988 if (!obj->rtld) { 989 Needed_Entry *nep = NEW(Needed_Entry); 990 nep->name = dynp->d_un.d_val; 991 nep->obj = NULL; 992 nep->next = NULL; 993 994 *needed_tail = nep; 995 needed_tail = &nep->next; 996 } 997 break; 998 999 case DT_FILTER: 1000 if (!obj->rtld) { 1001 Needed_Entry *nep = NEW(Needed_Entry); 1002 nep->name = dynp->d_un.d_val; 1003 nep->obj = NULL; 1004 nep->next = NULL; 1005 1006 *needed_filtees_tail = nep; 1007 needed_filtees_tail = &nep->next; 1008 } 1009 break; 1010 1011 case DT_AUXILIARY: 1012 if (!obj->rtld) { 1013 Needed_Entry *nep = NEW(Needed_Entry); 1014 nep->name = dynp->d_un.d_val; 1015 nep->obj = NULL; 1016 nep->next = NULL; 1017 1018 *needed_aux_filtees_tail = nep; 1019 needed_aux_filtees_tail = &nep->next; 1020 } 1021 break; 1022 1023 case DT_PLTGOT: 1024 obj->pltgot = (Elf_Addr *) (obj->relocbase + dynp->d_un.d_ptr); 1025 break; 1026 1027 case DT_TEXTREL: 1028 obj->textrel = true; 1029 break; 1030 1031 case DT_SYMBOLIC: 1032 obj->symbolic = true; 1033 break; 1034 1035 case DT_RPATH: 1036 /* 1037 * We have to wait until later to process this, because we 1038 * might not have gotten the address of the string table yet. 1039 */ 1040 *dyn_rpath = dynp; 1041 break; 1042 1043 case DT_SONAME: 1044 *dyn_soname = dynp; 1045 break; 1046 1047 case DT_RUNPATH: 1048 *dyn_runpath = dynp; 1049 break; 1050 1051 case DT_INIT: 1052 obj->init = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr); 1053 break; 1054 1055 case DT_PREINIT_ARRAY: 1056 obj->preinit_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1057 break; 1058 1059 case DT_PREINIT_ARRAYSZ: 1060 obj->preinit_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1061 break; 1062 1063 case DT_INIT_ARRAY: 1064 obj->init_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1065 break; 1066 1067 case DT_INIT_ARRAYSZ: 1068 obj->init_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1069 break; 1070 1071 case DT_FINI: 1072 obj->fini = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr); 1073 break; 1074 1075 case DT_FINI_ARRAY: 1076 obj->fini_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1077 break; 1078 1079 case DT_FINI_ARRAYSZ: 1080 obj->fini_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1081 break; 1082 1083 /* 1084 * Don't process DT_DEBUG on MIPS as the dynamic section 1085 * is mapped read-only. DT_MIPS_RLD_MAP is used instead. 1086 */ 1087 1088#ifndef __mips__ 1089 case DT_DEBUG: 1090 /* XXX - not implemented yet */ 1091 if (!early) 1092 dbg("Filling in DT_DEBUG entry"); 1093 ((Elf_Dyn*)dynp)->d_un.d_ptr = (Elf_Addr) &r_debug; 1094 break; 1095#endif 1096 1097 case DT_FLAGS: 1098 if ((dynp->d_un.d_val & DF_ORIGIN) && trust) 1099 obj->z_origin = true; 1100 if (dynp->d_un.d_val & DF_SYMBOLIC) 1101 obj->symbolic = true; 1102 if (dynp->d_un.d_val & DF_TEXTREL) 1103 obj->textrel = true; 1104 if (dynp->d_un.d_val & DF_BIND_NOW) 1105 obj->bind_now = true; 1106 /*if (dynp->d_un.d_val & DF_STATIC_TLS) 1107 ;*/ 1108 break; 1109#ifdef __mips__ 1110 case DT_MIPS_LOCAL_GOTNO: 1111 obj->local_gotno = dynp->d_un.d_val; 1112 break; 1113 1114 case DT_MIPS_SYMTABNO: 1115 obj->symtabno = dynp->d_un.d_val; 1116 break; 1117 1118 case DT_MIPS_GOTSYM: 1119 obj->gotsym = dynp->d_un.d_val; 1120 break; 1121 1122 case DT_MIPS_RLD_MAP: 1123 *((Elf_Addr *)(dynp->d_un.d_ptr)) = (Elf_Addr) &r_debug; 1124 break; 1125#endif 1126 1127 case DT_FLAGS_1: 1128 if (dynp->d_un.d_val & DF_1_NOOPEN) 1129 obj->z_noopen = true; 1130 if ((dynp->d_un.d_val & DF_1_ORIGIN) && trust) 1131 obj->z_origin = true; 1132 /*if (dynp->d_un.d_val & DF_1_GLOBAL) 1133 XXX ;*/ 1134 if (dynp->d_un.d_val & DF_1_BIND_NOW) 1135 obj->bind_now = true; 1136 if (dynp->d_un.d_val & DF_1_NODELETE) 1137 obj->z_nodelete = true; 1138 if (dynp->d_un.d_val & DF_1_LOADFLTR) 1139 obj->z_loadfltr = true; 1140 if (dynp->d_un.d_val & DF_1_INTERPOSE) 1141 obj->z_interpose = true; 1142 if (dynp->d_un.d_val & DF_1_NODEFLIB) 1143 obj->z_nodeflib = true; 1144 break; 1145 1146 default: 1147 if (!early) { 1148 dbg("Ignoring d_tag %ld = %#lx", (long)dynp->d_tag, 1149 (long)dynp->d_tag); 1150 } 1151 break; 1152 } 1153 } 1154 1155 obj->traced = false; 1156 1157 if (plttype == DT_RELA) { 1158 obj->pltrela = (const Elf_Rela *) obj->pltrel; 1159 obj->pltrel = NULL; 1160 obj->pltrelasize = obj->pltrelsize; 1161 obj->pltrelsize = 0; 1162 } 1163 1164 /* Determine size of dynsym table (equal to nchains of sysv hash) */ 1165 if (obj->valid_hash_sysv) 1166 obj->dynsymcount = obj->nchains; 1167 else if (obj->valid_hash_gnu) { 1168 obj->dynsymcount = 0; 1169 for (bkt = 0; bkt < obj->nbuckets_gnu; bkt++) { 1170 if (obj->buckets_gnu[bkt] == 0) 1171 continue; 1172 hashval = &obj->chain_zero_gnu[obj->buckets_gnu[bkt]]; 1173 do 1174 obj->dynsymcount++; 1175 while ((*hashval++ & 1u) == 0); 1176 } 1177 obj->dynsymcount += obj->symndx_gnu; 1178 } 1179} 1180 1181static void 1182digest_dynamic2(Obj_Entry *obj, const Elf_Dyn *dyn_rpath, 1183 const Elf_Dyn *dyn_soname, const Elf_Dyn *dyn_runpath) 1184{ 1185 1186 if (obj->z_origin && obj->origin_path == NULL) { 1187 obj->origin_path = xmalloc(PATH_MAX); 1188 if (rtld_dirname_abs(obj->path, obj->origin_path) == -1) 1189 die(); 1190 } 1191 1192 if (dyn_runpath != NULL) { 1193 obj->runpath = (char *)obj->strtab + dyn_runpath->d_un.d_val; 1194 if (obj->z_origin) 1195 obj->runpath = origin_subst(obj->runpath, obj->origin_path); 1196 } 1197 else if (dyn_rpath != NULL) { 1198 obj->rpath = (char *)obj->strtab + dyn_rpath->d_un.d_val; 1199 if (obj->z_origin) 1200 obj->rpath = origin_subst(obj->rpath, obj->origin_path); 1201 } 1202 1203 if (dyn_soname != NULL) 1204 object_add_name(obj, obj->strtab + dyn_soname->d_un.d_val); 1205} 1206 1207static void 1208digest_dynamic(Obj_Entry *obj, int early) 1209{ 1210 const Elf_Dyn *dyn_rpath; 1211 const Elf_Dyn *dyn_soname; 1212 const Elf_Dyn *dyn_runpath; 1213 1214 digest_dynamic1(obj, early, &dyn_rpath, &dyn_soname, &dyn_runpath); 1215 digest_dynamic2(obj, dyn_rpath, dyn_soname, dyn_runpath); 1216} 1217 1218/* 1219 * Process a shared object's program header. This is used only for the 1220 * main program, when the kernel has already loaded the main program 1221 * into memory before calling the dynamic linker. It creates and 1222 * returns an Obj_Entry structure. 1223 */ 1224static Obj_Entry * 1225digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path) 1226{ 1227 Obj_Entry *obj; 1228 const Elf_Phdr *phlimit = phdr + phnum; 1229 const Elf_Phdr *ph; 1230 Elf_Addr note_start, note_end; 1231 int nsegs = 0; 1232 1233 obj = obj_new(); 1234 for (ph = phdr; ph < phlimit; ph++) { 1235 if (ph->p_type != PT_PHDR) 1236 continue; 1237 1238 obj->phdr = phdr; 1239 obj->phsize = ph->p_memsz; 1240 obj->relocbase = (caddr_t)phdr - ph->p_vaddr; 1241 break; 1242 } 1243 1244 obj->stack_flags = PF_X | PF_R | PF_W; 1245 1246 for (ph = phdr; ph < phlimit; ph++) { 1247 switch (ph->p_type) { 1248 1249 case PT_INTERP: 1250 obj->interp = (const char *)(ph->p_vaddr + obj->relocbase); 1251 break; 1252 1253 case PT_LOAD: 1254 if (nsegs == 0) { /* First load segment */ 1255 obj->vaddrbase = trunc_page(ph->p_vaddr); 1256 obj->mapbase = obj->vaddrbase + obj->relocbase; 1257 obj->textsize = round_page(ph->p_vaddr + ph->p_memsz) - 1258 obj->vaddrbase; 1259 } else { /* Last load segment */ 1260 obj->mapsize = round_page(ph->p_vaddr + ph->p_memsz) - 1261 obj->vaddrbase; 1262 } 1263 nsegs++; 1264 break; 1265 1266 case PT_DYNAMIC: 1267 obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + obj->relocbase); 1268 break; 1269 1270 case PT_TLS: 1271 obj->tlsindex = 1; 1272 obj->tlssize = ph->p_memsz; 1273 obj->tlsalign = ph->p_align; 1274 obj->tlsinitsize = ph->p_filesz; 1275 obj->tlsinit = (void*)(ph->p_vaddr + obj->relocbase); 1276 break; 1277 1278 case PT_GNU_STACK: 1279 obj->stack_flags = ph->p_flags; 1280 break; 1281 1282 case PT_GNU_RELRO: 1283 obj->relro_page = obj->relocbase + trunc_page(ph->p_vaddr); 1284 obj->relro_size = round_page(ph->p_memsz); 1285 break; 1286 1287 case PT_NOTE: 1288 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; 1289 note_end = note_start + ph->p_filesz; 1290 digest_notes(obj, note_start, note_end); 1291 break; 1292 } 1293 } 1294 if (nsegs < 1) { 1295 _rtld_error("%s: too few PT_LOAD segments", path); 1296 return NULL; 1297 } 1298 1299 obj->entry = entry; 1300 return obj; 1301} 1302 1303void 1304digest_notes(Obj_Entry *obj, Elf_Addr note_start, Elf_Addr note_end) 1305{ 1306 const Elf_Note *note; 1307 const char *note_name; 1308 uintptr_t p; 1309 1310 for (note = (const Elf_Note *)note_start; (Elf_Addr)note < note_end; 1311 note = (const Elf_Note *)((const char *)(note + 1) + 1312 roundup2(note->n_namesz, sizeof(Elf32_Addr)) + 1313 roundup2(note->n_descsz, sizeof(Elf32_Addr)))) { 1314 if (note->n_namesz != sizeof(NOTE_FREEBSD_VENDOR) || 1315 note->n_descsz != sizeof(int32_t)) 1316 continue; 1317 if (note->n_type != ABI_NOTETYPE && 1318 note->n_type != CRT_NOINIT_NOTETYPE) 1319 continue; 1320 note_name = (const char *)(note + 1); 1321 if (strncmp(NOTE_FREEBSD_VENDOR, note_name, 1322 sizeof(NOTE_FREEBSD_VENDOR)) != 0) 1323 continue; 1324 switch (note->n_type) { 1325 case ABI_NOTETYPE: 1326 /* FreeBSD osrel note */ 1327 p = (uintptr_t)(note + 1); 1328 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1329 obj->osrel = *(const int32_t *)(p); 1330 dbg("note osrel %d", obj->osrel); 1331 break; 1332 case CRT_NOINIT_NOTETYPE: 1333 /* FreeBSD 'crt does not call init' note */ 1334 obj->crt_no_init = true; 1335 dbg("note crt_no_init"); 1336 break; 1337 } 1338 } 1339} 1340 1341static Obj_Entry * 1342dlcheck(void *handle) 1343{ 1344 Obj_Entry *obj; 1345 1346 for (obj = obj_list; obj != NULL; obj = obj->next) 1347 if (obj == (Obj_Entry *) handle) 1348 break; 1349 1350 if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) { 1351 _rtld_error("Invalid shared object handle %p", handle); 1352 return NULL; 1353 } 1354 return obj; 1355} 1356 1357/* 1358 * If the given object is already in the donelist, return true. Otherwise 1359 * add the object to the list and return false. 1360 */ 1361static bool 1362donelist_check(DoneList *dlp, const Obj_Entry *obj) 1363{ 1364 unsigned int i; 1365 1366 for (i = 0; i < dlp->num_used; i++) 1367 if (dlp->objs[i] == obj) 1368 return true; 1369 /* 1370 * Our donelist allocation should always be sufficient. But if 1371 * our threads locking isn't working properly, more shared objects 1372 * could have been loaded since we allocated the list. That should 1373 * never happen, but we'll handle it properly just in case it does. 1374 */ 1375 if (dlp->num_used < dlp->num_alloc) 1376 dlp->objs[dlp->num_used++] = obj; 1377 return false; 1378} 1379 1380/* 1381 * Hash function for symbol table lookup. Don't even think about changing 1382 * this. It is specified by the System V ABI. 1383 */ 1384unsigned long 1385elf_hash(const char *name) 1386{ 1387 const unsigned char *p = (const unsigned char *) name; 1388 unsigned long h = 0; 1389 unsigned long g; 1390 1391 while (*p != '\0') { 1392 h = (h << 4) + *p++; 1393 if ((g = h & 0xf0000000) != 0) 1394 h ^= g >> 24; 1395 h &= ~g; 1396 } 1397 return h; 1398} 1399 1400/* 1401 * The GNU hash function is the Daniel J. Bernstein hash clipped to 32 bits 1402 * unsigned in case it's implemented with a wider type. 1403 */ 1404static uint32_t 1405gnu_hash(const char *s) 1406{ 1407 uint32_t h; 1408 unsigned char c; 1409 1410 h = 5381; 1411 for (c = *s; c != '\0'; c = *++s) 1412 h = h * 33 + c; 1413 return (h & 0xffffffff); 1414} 1415 1416/* 1417 * Find the library with the given name, and return its full pathname. 1418 * The returned string is dynamically allocated. Generates an error 1419 * message and returns NULL if the library cannot be found. 1420 * 1421 * If the second argument is non-NULL, then it refers to an already- 1422 * loaded shared object, whose library search path will be searched. 1423 * 1424 * The search order is: 1425 * DT_RPATH in the referencing file _unless_ DT_RUNPATH is present (1) 1426 * DT_RPATH of the main object if DSO without defined DT_RUNPATH (1) 1427 * LD_LIBRARY_PATH 1428 * DT_RUNPATH in the referencing file 1429 * ldconfig hints (if -z nodefaultlib, filter out default library directories 1430 * from list) 1431 * /lib:/usr/lib _unless_ the referencing file is linked with -z nodefaultlib 1432 * 1433 * (1) Handled in digest_dynamic2 - rpath left NULL if runpath defined. 1434 */ 1435static char * 1436find_library(const char *xname, const Obj_Entry *refobj) 1437{ 1438 char *pathname; 1439 char *name; 1440 bool nodeflib, objgiven; 1441 1442 objgiven = refobj != NULL; 1443 if (strchr(xname, '/') != NULL) { /* Hard coded pathname */ 1444 if (xname[0] != '/' && !trust) { 1445 _rtld_error("Absolute pathname required for shared object \"%s\"", 1446 xname); 1447 return NULL; 1448 } 1449 if (objgiven && refobj->z_origin) { 1450 return (origin_subst(__DECONST(char *, xname), 1451 refobj->origin_path)); 1452 } else { 1453 return (xstrdup(xname)); 1454 } 1455 } 1456 1457 if (libmap_disable || !objgiven || 1458 (name = lm_find(refobj->path, xname)) == NULL) 1459 name = (char *)xname; 1460 1461 dbg(" Searching for \"%s\"", name); 1462 1463 /* 1464 * If refobj->rpath != NULL, then refobj->runpath is NULL. Fall 1465 * back to pre-conforming behaviour if user requested so with 1466 * LD_LIBRARY_PATH_RPATH environment variable and ignore -z 1467 * nodeflib. 1468 */ 1469 if (objgiven && refobj->rpath != NULL && ld_library_path_rpath) { 1470 if ((pathname = search_library_path(name, ld_library_path)) != NULL || 1471 (refobj != NULL && 1472 (pathname = search_library_path(name, refobj->rpath)) != NULL) || 1473 (pathname = search_library_path(name, gethints(false))) != NULL || 1474 (pathname = search_library_path(name, STANDARD_LIBRARY_PATH)) != NULL) 1475 return (pathname); 1476 } else { 1477 nodeflib = objgiven ? refobj->z_nodeflib : false; 1478 if ((objgiven && 1479 (pathname = search_library_path(name, refobj->rpath)) != NULL) || 1480 (objgiven && refobj->runpath == NULL && refobj != obj_main && 1481 (pathname = search_library_path(name, obj_main->rpath)) != NULL) || 1482 (pathname = search_library_path(name, ld_library_path)) != NULL || 1483 (objgiven && 1484 (pathname = search_library_path(name, refobj->runpath)) != NULL) || 1485 (pathname = search_library_path(name, gethints(nodeflib))) != NULL || 1486 (objgiven && !nodeflib && 1487 (pathname = search_library_path(name, STANDARD_LIBRARY_PATH)) != NULL)) 1488 return (pathname); 1489 } 1490 1491 if (objgiven && refobj->path != NULL) { 1492 _rtld_error("Shared object \"%s\" not found, required by \"%s\"", 1493 name, basename(refobj->path)); 1494 } else { 1495 _rtld_error("Shared object \"%s\" not found", name); 1496 } 1497 return NULL; 1498} 1499 1500/* 1501 * Given a symbol number in a referencing object, find the corresponding 1502 * definition of the symbol. Returns a pointer to the symbol, or NULL if 1503 * no definition was found. Returns a pointer to the Obj_Entry of the 1504 * defining object via the reference parameter DEFOBJ_OUT. 1505 */ 1506const Elf_Sym * 1507find_symdef(unsigned long symnum, const Obj_Entry *refobj, 1508 const Obj_Entry **defobj_out, int flags, SymCache *cache, 1509 RtldLockState *lockstate) 1510{ 1511 const Elf_Sym *ref; 1512 const Elf_Sym *def; 1513 const Obj_Entry *defobj; 1514 SymLook req; 1515 const char *name; 1516 int res; 1517 1518 /* 1519 * If we have already found this symbol, get the information from 1520 * the cache. 1521 */ 1522 if (symnum >= refobj->dynsymcount) 1523 return NULL; /* Bad object */ 1524 if (cache != NULL && cache[symnum].sym != NULL) { 1525 *defobj_out = cache[symnum].obj; 1526 return cache[symnum].sym; 1527 } 1528 1529 ref = refobj->symtab + symnum; 1530 name = refobj->strtab + ref->st_name; 1531 def = NULL; 1532 defobj = NULL; 1533 1534 /* 1535 * We don't have to do a full scale lookup if the symbol is local. 1536 * We know it will bind to the instance in this load module; to 1537 * which we already have a pointer (ie ref). By not doing a lookup, 1538 * we not only improve performance, but it also avoids unresolvable 1539 * symbols when local symbols are not in the hash table. This has 1540 * been seen with the ia64 toolchain. 1541 */ 1542 if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) { 1543 if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) { 1544 _rtld_error("%s: Bogus symbol table entry %lu", refobj->path, 1545 symnum); 1546 } 1547 symlook_init(&req, name); 1548 req.flags = flags; 1549 req.ventry = fetch_ventry(refobj, symnum); 1550 req.lockstate = lockstate; 1551 res = symlook_default(&req, refobj); 1552 if (res == 0) { 1553 def = req.sym_out; 1554 defobj = req.defobj_out; 1555 } 1556 } else { 1557 def = ref; 1558 defobj = refobj; 1559 } 1560 1561 /* 1562 * If we found no definition and the reference is weak, treat the 1563 * symbol as having the value zero. 1564 */ 1565 if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) { 1566 def = &sym_zero; 1567 defobj = obj_main; 1568 } 1569 1570 if (def != NULL) { 1571 *defobj_out = defobj; 1572 /* Record the information in the cache to avoid subsequent lookups. */ 1573 if (cache != NULL) { 1574 cache[symnum].sym = def; 1575 cache[symnum].obj = defobj; 1576 } 1577 } else { 1578 if (refobj != &obj_rtld) 1579 _rtld_error("%s: Undefined symbol \"%s\"", refobj->path, name); 1580 } 1581 return def; 1582} 1583 1584/* 1585 * Return the search path from the ldconfig hints file, reading it if 1586 * necessary. If nostdlib is true, then the default search paths are 1587 * not added to result. 1588 * 1589 * Returns NULL if there are problems with the hints file, 1590 * or if the search path there is empty. 1591 */ 1592static const char * 1593gethints(bool nostdlib) 1594{ 1595 static char *hints, *filtered_path; 1596 struct elfhints_hdr hdr; 1597 struct fill_search_info_args sargs, hargs; 1598 struct dl_serinfo smeta, hmeta, *SLPinfo, *hintinfo; 1599 struct dl_serpath *SLPpath, *hintpath; 1600 char *p; 1601 unsigned int SLPndx, hintndx, fndx, fcount; 1602 int fd; 1603 size_t flen; 1604 bool skip; 1605 1606 /* First call, read the hints file */ 1607 if (hints == NULL) { 1608 /* Keep from trying again in case the hints file is bad. */ 1609 hints = ""; 1610 1611 if ((fd = open(ld_elf_hints_path, O_RDONLY | O_CLOEXEC)) == -1) 1612 return (NULL); 1613 if (read(fd, &hdr, sizeof hdr) != sizeof hdr || 1614 hdr.magic != ELFHINTS_MAGIC || 1615 hdr.version != 1) { 1616 close(fd); 1617 return (NULL); 1618 } 1619 p = xmalloc(hdr.dirlistlen + 1); 1620 if (lseek(fd, hdr.strtab + hdr.dirlist, SEEK_SET) == -1 || 1621 read(fd, p, hdr.dirlistlen + 1) != 1622 (ssize_t)hdr.dirlistlen + 1) { 1623 free(p); 1624 close(fd); 1625 return (NULL); 1626 } 1627 hints = p; 1628 close(fd); 1629 } 1630 1631 /* 1632 * If caller agreed to receive list which includes the default 1633 * paths, we are done. Otherwise, if we still did not 1634 * calculated filtered result, do it now. 1635 */ 1636 if (!nostdlib) 1637 return (hints[0] != '\0' ? hints : NULL); 1638 if (filtered_path != NULL) 1639 goto filt_ret; 1640 1641 /* 1642 * Obtain the list of all configured search paths, and the 1643 * list of the default paths. 1644 * 1645 * First estimate the size of the results. 1646 */ 1647 smeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 1648 smeta.dls_cnt = 0; 1649 hmeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 1650 hmeta.dls_cnt = 0; 1651 1652 sargs.request = RTLD_DI_SERINFOSIZE; 1653 sargs.serinfo = &smeta; 1654 hargs.request = RTLD_DI_SERINFOSIZE; 1655 hargs.serinfo = &hmeta; 1656 1657 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &sargs); 1658 path_enumerate(p, fill_search_info, &hargs); 1659 1660 SLPinfo = xmalloc(smeta.dls_size); 1661 hintinfo = xmalloc(hmeta.dls_size); 1662 1663 /* 1664 * Next fetch both sets of paths. 1665 */ 1666 sargs.request = RTLD_DI_SERINFO; 1667 sargs.serinfo = SLPinfo; 1668 sargs.serpath = &SLPinfo->dls_serpath[0]; 1669 sargs.strspace = (char *)&SLPinfo->dls_serpath[smeta.dls_cnt]; 1670 1671 hargs.request = RTLD_DI_SERINFO; 1672 hargs.serinfo = hintinfo; 1673 hargs.serpath = &hintinfo->dls_serpath[0]; 1674 hargs.strspace = (char *)&hintinfo->dls_serpath[hmeta.dls_cnt]; 1675 1676 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &sargs); 1677 path_enumerate(p, fill_search_info, &hargs); 1678 1679 /* 1680 * Now calculate the difference between two sets, by excluding 1681 * standard paths from the full set. 1682 */ 1683 fndx = 0; 1684 fcount = 0; 1685 filtered_path = xmalloc(hdr.dirlistlen + 1); 1686 hintpath = &hintinfo->dls_serpath[0]; 1687 for (hintndx = 0; hintndx < hmeta.dls_cnt; hintndx++, hintpath++) { 1688 skip = false; 1689 SLPpath = &SLPinfo->dls_serpath[0]; 1690 /* 1691 * Check each standard path against current. 1692 */ 1693 for (SLPndx = 0; SLPndx < smeta.dls_cnt; SLPndx++, SLPpath++) { 1694 /* matched, skip the path */ 1695 if (!strcmp(hintpath->dls_name, SLPpath->dls_name)) { 1696 skip = true; 1697 break; 1698 } 1699 } 1700 if (skip) 1701 continue; 1702 /* 1703 * Not matched against any standard path, add the path 1704 * to result. Separate consequtive paths with ':'. 1705 */ 1706 if (fcount > 0) { 1707 filtered_path[fndx] = ':'; 1708 fndx++; 1709 } 1710 fcount++; 1711 flen = strlen(hintpath->dls_name); 1712 strncpy((filtered_path + fndx), hintpath->dls_name, flen); 1713 fndx += flen; 1714 } 1715 filtered_path[fndx] = '\0'; 1716 1717 free(SLPinfo); 1718 free(hintinfo); 1719 1720filt_ret: 1721 return (filtered_path[0] != '\0' ? filtered_path : NULL); 1722} 1723 1724static void 1725init_dag(Obj_Entry *root) 1726{ 1727 const Needed_Entry *needed; 1728 const Objlist_Entry *elm; 1729 DoneList donelist; 1730 1731 if (root->dag_inited) 1732 return; 1733 donelist_init(&donelist); 1734 1735 /* Root object belongs to own DAG. */ 1736 objlist_push_tail(&root->dldags, root); 1737 objlist_push_tail(&root->dagmembers, root); 1738 donelist_check(&donelist, root); 1739 1740 /* 1741 * Add dependencies of root object to DAG in breadth order 1742 * by exploiting the fact that each new object get added 1743 * to the tail of the dagmembers list. 1744 */ 1745 STAILQ_FOREACH(elm, &root->dagmembers, link) { 1746 for (needed = elm->obj->needed; needed != NULL; needed = needed->next) { 1747 if (needed->obj == NULL || donelist_check(&donelist, needed->obj)) 1748 continue; 1749 objlist_push_tail(&needed->obj->dldags, root); 1750 objlist_push_tail(&root->dagmembers, needed->obj); 1751 } 1752 } 1753 root->dag_inited = true; 1754} 1755 1756static void 1757process_nodelete(Obj_Entry *root) 1758{ 1759 const Objlist_Entry *elm; 1760 1761 /* 1762 * Walk over object DAG and process every dependent object that 1763 * is marked as DF_1_NODELETE. They need to grow their own DAG, 1764 * which then should have its reference upped separately. 1765 */ 1766 STAILQ_FOREACH(elm, &root->dagmembers, link) { 1767 if (elm->obj != NULL && elm->obj->z_nodelete && 1768 !elm->obj->ref_nodel) { 1769 dbg("obj %s nodelete", elm->obj->path); 1770 init_dag(elm->obj); 1771 ref_dag(elm->obj); 1772 elm->obj->ref_nodel = true; 1773 } 1774 } 1775} 1776/* 1777 * Initialize the dynamic linker. The argument is the address at which 1778 * the dynamic linker has been mapped into memory. The primary task of 1779 * this function is to relocate the dynamic linker. 1780 */ 1781static void 1782init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info) 1783{ 1784 Obj_Entry objtmp; /* Temporary rtld object */ 1785 const Elf_Dyn *dyn_rpath; 1786 const Elf_Dyn *dyn_soname; 1787 const Elf_Dyn *dyn_runpath; 1788 1789 /* 1790 * Conjure up an Obj_Entry structure for the dynamic linker. 1791 * 1792 * The "path" member can't be initialized yet because string constants 1793 * cannot yet be accessed. Below we will set it correctly. 1794 */ 1795 memset(&objtmp, 0, sizeof(objtmp)); 1796 objtmp.path = NULL; 1797 objtmp.rtld = true; 1798 objtmp.mapbase = mapbase; 1799#ifdef PIC 1800 objtmp.relocbase = mapbase; 1801#endif 1802 if (RTLD_IS_DYNAMIC()) { 1803 objtmp.dynamic = rtld_dynamic(&objtmp); 1804 digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname, &dyn_runpath); 1805 assert(objtmp.needed == NULL); 1806#if !defined(__mips__) 1807 /* MIPS has a bogus DT_TEXTREL. */ 1808 assert(!objtmp.textrel); 1809#endif 1810 1811 /* 1812 * Temporarily put the dynamic linker entry into the object list, so 1813 * that symbols can be found. 1814 */ 1815 1816 relocate_objects(&objtmp, true, &objtmp, 0, NULL); 1817 } 1818 1819 /* Initialize the object list. */ 1820 obj_tail = &obj_list; 1821 1822 /* Now that non-local variables can be accesses, copy out obj_rtld. */ 1823 memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld)); 1824 1825 if (aux_info[AT_PAGESZ] != NULL) 1826 pagesize = aux_info[AT_PAGESZ]->a_un.a_val; 1827 if (aux_info[AT_OSRELDATE] != NULL) 1828 osreldate = aux_info[AT_OSRELDATE]->a_un.a_val; 1829 1830 digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname, dyn_runpath); 1831 1832 /* Replace the path with a dynamically allocated copy. */ 1833 obj_rtld.path = xstrdup(PATH_RTLD); 1834 1835 r_debug.r_brk = r_debug_state; 1836 r_debug.r_state = RT_CONSISTENT; 1837} 1838 1839/* 1840 * Add the init functions from a needed object list (and its recursive 1841 * needed objects) to "list". This is not used directly; it is a helper 1842 * function for initlist_add_objects(). The write lock must be held 1843 * when this function is called. 1844 */ 1845static void 1846initlist_add_neededs(Needed_Entry *needed, Objlist *list) 1847{ 1848 /* Recursively process the successor needed objects. */ 1849 if (needed->next != NULL) 1850 initlist_add_neededs(needed->next, list); 1851 1852 /* Process the current needed object. */ 1853 if (needed->obj != NULL) 1854 initlist_add_objects(needed->obj, &needed->obj->next, list); 1855} 1856 1857/* 1858 * Scan all of the DAGs rooted in the range of objects from "obj" to 1859 * "tail" and add their init functions to "list". This recurses over 1860 * the DAGs and ensure the proper init ordering such that each object's 1861 * needed libraries are initialized before the object itself. At the 1862 * same time, this function adds the objects to the global finalization 1863 * list "list_fini" in the opposite order. The write lock must be 1864 * held when this function is called. 1865 */ 1866static void 1867initlist_add_objects(Obj_Entry *obj, Obj_Entry **tail, Objlist *list) 1868{ 1869 1870 if (obj->init_scanned || obj->init_done) 1871 return; 1872 obj->init_scanned = true; 1873 1874 /* Recursively process the successor objects. */ 1875 if (&obj->next != tail) 1876 initlist_add_objects(obj->next, tail, list); 1877 1878 /* Recursively process the needed objects. */ 1879 if (obj->needed != NULL) 1880 initlist_add_neededs(obj->needed, list); 1881 if (obj->needed_filtees != NULL) 1882 initlist_add_neededs(obj->needed_filtees, list); 1883 if (obj->needed_aux_filtees != NULL) 1884 initlist_add_neededs(obj->needed_aux_filtees, list); 1885 1886 /* Add the object to the init list. */ 1887 if (obj->preinit_array != (Elf_Addr)NULL || obj->init != (Elf_Addr)NULL || 1888 obj->init_array != (Elf_Addr)NULL) 1889 objlist_push_tail(list, obj); 1890 1891 /* Add the object to the global fini list in the reverse order. */ 1892 if ((obj->fini != (Elf_Addr)NULL || obj->fini_array != (Elf_Addr)NULL) 1893 && !obj->on_fini_list) { 1894 objlist_push_head(&list_fini, obj); 1895 obj->on_fini_list = true; 1896 } 1897} 1898 1899#ifndef FPTR_TARGET 1900#define FPTR_TARGET(f) ((Elf_Addr) (f)) 1901#endif 1902 1903static void 1904free_needed_filtees(Needed_Entry *n) 1905{ 1906 Needed_Entry *needed, *needed1; 1907 1908 for (needed = n; needed != NULL; needed = needed->next) { 1909 if (needed->obj != NULL) { 1910 dlclose(needed->obj); 1911 needed->obj = NULL; 1912 } 1913 } 1914 for (needed = n; needed != NULL; needed = needed1) { 1915 needed1 = needed->next; 1916 free(needed); 1917 } 1918} 1919 1920static void 1921unload_filtees(Obj_Entry *obj) 1922{ 1923 1924 free_needed_filtees(obj->needed_filtees); 1925 obj->needed_filtees = NULL; 1926 free_needed_filtees(obj->needed_aux_filtees); 1927 obj->needed_aux_filtees = NULL; 1928 obj->filtees_loaded = false; 1929} 1930 1931static void 1932load_filtee1(Obj_Entry *obj, Needed_Entry *needed, int flags, 1933 RtldLockState *lockstate) 1934{ 1935 1936 for (; needed != NULL; needed = needed->next) { 1937 needed->obj = dlopen_object(obj->strtab + needed->name, -1, obj, 1938 flags, ((ld_loadfltr || obj->z_loadfltr) ? RTLD_NOW : RTLD_LAZY) | 1939 RTLD_LOCAL, lockstate); 1940 } 1941} 1942 1943static void 1944load_filtees(Obj_Entry *obj, int flags, RtldLockState *lockstate) 1945{ 1946 1947 lock_restart_for_upgrade(lockstate); 1948 if (!obj->filtees_loaded) { 1949 load_filtee1(obj, obj->needed_filtees, flags, lockstate); 1950 load_filtee1(obj, obj->needed_aux_filtees, flags, lockstate); 1951 obj->filtees_loaded = true; 1952 } 1953} 1954 1955static int 1956process_needed(Obj_Entry *obj, Needed_Entry *needed, int flags) 1957{ 1958 Obj_Entry *obj1; 1959 1960 for (; needed != NULL; needed = needed->next) { 1961 obj1 = needed->obj = load_object(obj->strtab + needed->name, -1, obj, 1962 flags & ~RTLD_LO_NOLOAD); 1963 if (obj1 == NULL && !ld_tracing && (flags & RTLD_LO_FILTEES) == 0) 1964 return (-1); 1965 } 1966 return (0); 1967} 1968 1969/* 1970 * Given a shared object, traverse its list of needed objects, and load 1971 * each of them. Returns 0 on success. Generates an error message and 1972 * returns -1 on failure. 1973 */ 1974static int 1975load_needed_objects(Obj_Entry *first, int flags) 1976{ 1977 Obj_Entry *obj; 1978 1979 for (obj = first; obj != NULL; obj = obj->next) { 1980 if (process_needed(obj, obj->needed, flags) == -1) 1981 return (-1); 1982 } 1983 return (0); 1984} 1985 1986static int 1987load_preload_objects(void) 1988{ 1989 char *p = ld_preload; 1990 Obj_Entry *obj; 1991 static const char delim[] = " \t:;"; 1992 1993 if (p == NULL) 1994 return 0; 1995 1996 p += strspn(p, delim); 1997 while (*p != '\0') { 1998 size_t len = strcspn(p, delim); 1999 char savech; 2000 2001 savech = p[len]; 2002 p[len] = '\0'; 2003 obj = load_object(p, -1, NULL, 0); 2004 if (obj == NULL) 2005 return -1; /* XXX - cleanup */ 2006 obj->z_interpose = true; 2007 p[len] = savech; 2008 p += len; 2009 p += strspn(p, delim); 2010 } 2011 LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL); 2012 return 0; 2013} 2014 2015static const char * 2016printable_path(const char *path) 2017{ 2018 2019 return (path == NULL ? "<unknown>" : path); 2020} 2021 2022/* 2023 * Load a shared object into memory, if it is not already loaded. The 2024 * object may be specified by name or by user-supplied file descriptor 2025 * fd_u. In the later case, the fd_u descriptor is not closed, but its 2026 * duplicate is. 2027 * 2028 * Returns a pointer to the Obj_Entry for the object. Returns NULL 2029 * on failure. 2030 */ 2031static Obj_Entry * 2032load_object(const char *name, int fd_u, const Obj_Entry *refobj, int flags) 2033{ 2034 Obj_Entry *obj; 2035 int fd; 2036 struct stat sb; 2037 char *path; 2038 2039 if (name != NULL) { 2040 for (obj = obj_list->next; obj != NULL; obj = obj->next) { 2041 if (object_match_name(obj, name)) 2042 return (obj); 2043 } 2044 2045 path = find_library(name, refobj); 2046 if (path == NULL) 2047 return (NULL); 2048 } else 2049 path = NULL; 2050 2051 /* 2052 * If we didn't find a match by pathname, or the name is not 2053 * supplied, open the file and check again by device and inode. 2054 * This avoids false mismatches caused by multiple links or ".." 2055 * in pathnames. 2056 * 2057 * To avoid a race, we open the file and use fstat() rather than 2058 * using stat(). 2059 */ 2060 fd = -1; 2061 if (fd_u == -1) { 2062 if ((fd = open(path, O_RDONLY | O_CLOEXEC)) == -1) { 2063 _rtld_error("Cannot open \"%s\"", path); 2064 free(path); 2065 return (NULL); 2066 } 2067 } else { 2068 fd = fcntl(fd_u, F_DUPFD_CLOEXEC, 0); 2069 if (fd == -1) { 2070 _rtld_error("Cannot dup fd"); 2071 free(path); 2072 return (NULL); 2073 } 2074 } 2075 if (fstat(fd, &sb) == -1) { 2076 _rtld_error("Cannot fstat \"%s\"", printable_path(path)); 2077 close(fd); 2078 free(path); 2079 return NULL; 2080 } 2081 for (obj = obj_list->next; obj != NULL; obj = obj->next) 2082 if (obj->ino == sb.st_ino && obj->dev == sb.st_dev) 2083 break; 2084 if (obj != NULL && name != NULL) { 2085 object_add_name(obj, name); 2086 free(path); 2087 close(fd); 2088 return obj; 2089 } 2090 if (flags & RTLD_LO_NOLOAD) { 2091 free(path); 2092 close(fd); 2093 return (NULL); 2094 } 2095 2096 /* First use of this object, so we must map it in */ 2097 obj = do_load_object(fd, name, path, &sb, flags); 2098 if (obj == NULL) 2099 free(path); 2100 close(fd); 2101 2102 return obj; 2103} 2104 2105static Obj_Entry * 2106do_load_object(int fd, const char *name, char *path, struct stat *sbp, 2107 int flags) 2108{ 2109 Obj_Entry *obj; 2110 struct statfs fs; 2111 2112 /* 2113 * but first, make sure that environment variables haven't been 2114 * used to circumvent the noexec flag on a filesystem. 2115 */ 2116 if (dangerous_ld_env) { 2117 if (fstatfs(fd, &fs) != 0) { 2118 _rtld_error("Cannot fstatfs \"%s\"", printable_path(path)); 2119 return NULL; 2120 } 2121 if (fs.f_flags & MNT_NOEXEC) { 2122 _rtld_error("Cannot execute objects on %s\n", fs.f_mntonname); 2123 return NULL; 2124 } 2125 } 2126 dbg("loading \"%s\"", printable_path(path)); 2127 obj = map_object(fd, printable_path(path), sbp); 2128 if (obj == NULL) 2129 return NULL; 2130 2131 /* 2132 * If DT_SONAME is present in the object, digest_dynamic2 already 2133 * added it to the object names. 2134 */ 2135 if (name != NULL) 2136 object_add_name(obj, name); 2137 obj->path = path; 2138 digest_dynamic(obj, 0); 2139 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", obj->path, 2140 obj->valid_hash_sysv, obj->valid_hash_gnu, obj->dynsymcount); 2141 if (obj->z_noopen && (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) == 2142 RTLD_LO_DLOPEN) { 2143 dbg("refusing to load non-loadable \"%s\"", obj->path); 2144 _rtld_error("Cannot dlopen non-loadable %s", obj->path); 2145 munmap(obj->mapbase, obj->mapsize); 2146 obj_free(obj); 2147 return (NULL); 2148 } 2149 2150 obj->dlopened = (flags & RTLD_LO_DLOPEN) != 0; 2151 *obj_tail = obj; 2152 obj_tail = &obj->next; 2153 obj_count++; 2154 obj_loads++; 2155 linkmap_add(obj); /* for GDB & dlinfo() */ 2156 max_stack_flags |= obj->stack_flags; 2157 2158 dbg(" %p .. %p: %s", obj->mapbase, 2159 obj->mapbase + obj->mapsize - 1, obj->path); 2160 if (obj->textrel) 2161 dbg(" WARNING: %s has impure text", obj->path); 2162 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 2163 obj->path); 2164 2165 return obj; 2166} 2167 2168static Obj_Entry * 2169obj_from_addr(const void *addr) 2170{ 2171 Obj_Entry *obj; 2172 2173 for (obj = obj_list; obj != NULL; obj = obj->next) { 2174 if (addr < (void *) obj->mapbase) 2175 continue; 2176 if (addr < (void *) (obj->mapbase + obj->mapsize)) 2177 return obj; 2178 } 2179 return NULL; 2180} 2181 2182static void 2183preinit_main(void) 2184{ 2185 Elf_Addr *preinit_addr; 2186 int index; 2187 2188 preinit_addr = (Elf_Addr *)obj_main->preinit_array; 2189 if (preinit_addr == NULL) 2190 return; 2191 2192 for (index = 0; index < obj_main->preinit_array_num; index++) { 2193 if (preinit_addr[index] != 0 && preinit_addr[index] != 1) { 2194 dbg("calling preinit function for %s at %p", obj_main->path, 2195 (void *)preinit_addr[index]); 2196 LD_UTRACE(UTRACE_INIT_CALL, obj_main, (void *)preinit_addr[index], 2197 0, 0, obj_main->path); 2198 call_init_pointer(obj_main, preinit_addr[index]); 2199 } 2200 } 2201} 2202 2203/* 2204 * Call the finalization functions for each of the objects in "list" 2205 * belonging to the DAG of "root" and referenced once. If NULL "root" 2206 * is specified, every finalization function will be called regardless 2207 * of the reference count and the list elements won't be freed. All of 2208 * the objects are expected to have non-NULL fini functions. 2209 */ 2210static void 2211objlist_call_fini(Objlist *list, Obj_Entry *root, RtldLockState *lockstate) 2212{ 2213 Objlist_Entry *elm; 2214 char *saved_msg; 2215 Elf_Addr *fini_addr; 2216 int index; 2217 2218 assert(root == NULL || root->refcount == 1); 2219 2220 /* 2221 * Preserve the current error message since a fini function might 2222 * call into the dynamic linker and overwrite it. 2223 */ 2224 saved_msg = errmsg_save(); 2225 do { 2226 STAILQ_FOREACH(elm, list, link) { 2227 if (root != NULL && (elm->obj->refcount != 1 || 2228 objlist_find(&root->dagmembers, elm->obj) == NULL)) 2229 continue; 2230 /* Remove object from fini list to prevent recursive invocation. */ 2231 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 2232 /* 2233 * XXX: If a dlopen() call references an object while the 2234 * fini function is in progress, we might end up trying to 2235 * unload the referenced object in dlclose() or the object 2236 * won't be unloaded although its fini function has been 2237 * called. 2238 */ 2239 lock_release(rtld_bind_lock, lockstate); 2240 2241 /* 2242 * It is legal to have both DT_FINI and DT_FINI_ARRAY defined. 2243 * When this happens, DT_FINI_ARRAY is processed first. 2244 */ 2245 fini_addr = (Elf_Addr *)elm->obj->fini_array; 2246 if (fini_addr != NULL && elm->obj->fini_array_num > 0) { 2247 for (index = elm->obj->fini_array_num - 1; index >= 0; 2248 index--) { 2249 if (fini_addr[index] != 0 && fini_addr[index] != 1) { 2250 dbg("calling fini function for %s at %p", 2251 elm->obj->path, (void *)fini_addr[index]); 2252 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, 2253 (void *)fini_addr[index], 0, 0, elm->obj->path); 2254 call_initfini_pointer(elm->obj, fini_addr[index]); 2255 } 2256 } 2257 } 2258 if (elm->obj->fini != (Elf_Addr)NULL) { 2259 dbg("calling fini function for %s at %p", elm->obj->path, 2260 (void *)elm->obj->fini); 2261 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, (void *)elm->obj->fini, 2262 0, 0, elm->obj->path); 2263 call_initfini_pointer(elm->obj, elm->obj->fini); 2264 } 2265 wlock_acquire(rtld_bind_lock, lockstate); 2266 /* No need to free anything if process is going down. */ 2267 if (root != NULL) 2268 free(elm); 2269 /* 2270 * We must restart the list traversal after every fini call 2271 * because a dlclose() call from the fini function or from 2272 * another thread might have modified the reference counts. 2273 */ 2274 break; 2275 } 2276 } while (elm != NULL); 2277 errmsg_restore(saved_msg); 2278} 2279 2280/* 2281 * Call the initialization functions for each of the objects in 2282 * "list". All of the objects are expected to have non-NULL init 2283 * functions. 2284 */ 2285static void 2286objlist_call_init(Objlist *list, RtldLockState *lockstate) 2287{ 2288 Objlist_Entry *elm; 2289 Obj_Entry *obj; 2290 char *saved_msg; 2291 Elf_Addr *init_addr; 2292 int index; 2293 2294 /* 2295 * Clean init_scanned flag so that objects can be rechecked and 2296 * possibly initialized earlier if any of vectors called below 2297 * cause the change by using dlopen. 2298 */ 2299 for (obj = obj_list; obj != NULL; obj = obj->next) 2300 obj->init_scanned = false; 2301 2302 /* 2303 * Preserve the current error message since an init function might 2304 * call into the dynamic linker and overwrite it. 2305 */ 2306 saved_msg = errmsg_save(); 2307 STAILQ_FOREACH(elm, list, link) { 2308 if (elm->obj->init_done) /* Initialized early. */ 2309 continue; 2310 /* 2311 * Race: other thread might try to use this object before current 2312 * one completes the initilization. Not much can be done here 2313 * without better locking. 2314 */ 2315 elm->obj->init_done = true; 2316 lock_release(rtld_bind_lock, lockstate); 2317 2318 /* 2319 * It is legal to have both DT_INIT and DT_INIT_ARRAY defined. 2320 * When this happens, DT_INIT is processed first. 2321 */ 2322 if (elm->obj->init != (Elf_Addr)NULL) { 2323 dbg("calling init function for %s at %p", elm->obj->path, 2324 (void *)elm->obj->init); 2325 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, (void *)elm->obj->init, 2326 0, 0, elm->obj->path); 2327 call_initfini_pointer(elm->obj, elm->obj->init); 2328 } 2329 init_addr = (Elf_Addr *)elm->obj->init_array; 2330 if (init_addr != NULL) { 2331 for (index = 0; index < elm->obj->init_array_num; index++) { 2332 if (init_addr[index] != 0 && init_addr[index] != 1) { 2333 dbg("calling init function for %s at %p", elm->obj->path, 2334 (void *)init_addr[index]); 2335 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, 2336 (void *)init_addr[index], 0, 0, elm->obj->path); 2337 call_init_pointer(elm->obj, init_addr[index]); 2338 } 2339 } 2340 } 2341 wlock_acquire(rtld_bind_lock, lockstate); 2342 } 2343 errmsg_restore(saved_msg); 2344} 2345 2346static void 2347objlist_clear(Objlist *list) 2348{ 2349 Objlist_Entry *elm; 2350 2351 while (!STAILQ_EMPTY(list)) { 2352 elm = STAILQ_FIRST(list); 2353 STAILQ_REMOVE_HEAD(list, link); 2354 free(elm); 2355 } 2356} 2357 2358static Objlist_Entry * 2359objlist_find(Objlist *list, const Obj_Entry *obj) 2360{ 2361 Objlist_Entry *elm; 2362 2363 STAILQ_FOREACH(elm, list, link) 2364 if (elm->obj == obj) 2365 return elm; 2366 return NULL; 2367} 2368 2369static void 2370objlist_init(Objlist *list) 2371{ 2372 STAILQ_INIT(list); 2373} 2374 2375static void 2376objlist_push_head(Objlist *list, Obj_Entry *obj) 2377{ 2378 Objlist_Entry *elm; 2379 2380 elm = NEW(Objlist_Entry); 2381 elm->obj = obj; 2382 STAILQ_INSERT_HEAD(list, elm, link); 2383} 2384 2385static void 2386objlist_push_tail(Objlist *list, Obj_Entry *obj) 2387{ 2388 Objlist_Entry *elm; 2389 2390 elm = NEW(Objlist_Entry); 2391 elm->obj = obj; 2392 STAILQ_INSERT_TAIL(list, elm, link); 2393} 2394 2395static void 2396objlist_put_after(Objlist *list, Obj_Entry *listobj, Obj_Entry *obj) 2397{ 2398 Objlist_Entry *elm, *listelm; 2399 2400 STAILQ_FOREACH(listelm, list, link) { 2401 if (listelm->obj == listobj) 2402 break; 2403 } 2404 elm = NEW(Objlist_Entry); 2405 elm->obj = obj; 2406 if (listelm != NULL) 2407 STAILQ_INSERT_AFTER(list, listelm, elm, link); 2408 else 2409 STAILQ_INSERT_TAIL(list, elm, link); 2410} 2411 2412static void 2413objlist_remove(Objlist *list, Obj_Entry *obj) 2414{ 2415 Objlist_Entry *elm; 2416 2417 if ((elm = objlist_find(list, obj)) != NULL) { 2418 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 2419 free(elm); 2420 } 2421} 2422 2423/* 2424 * Relocate dag rooted in the specified object. 2425 * Returns 0 on success, or -1 on failure. 2426 */ 2427 2428static int 2429relocate_object_dag(Obj_Entry *root, bool bind_now, Obj_Entry *rtldobj, 2430 int flags, RtldLockState *lockstate) 2431{ 2432 Objlist_Entry *elm; 2433 int error; 2434 2435 error = 0; 2436 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2437 error = relocate_object(elm->obj, bind_now, rtldobj, flags, 2438 lockstate); 2439 if (error == -1) 2440 break; 2441 } 2442 return (error); 2443} 2444 2445/* 2446 * Relocate single object. 2447 * Returns 0 on success, or -1 on failure. 2448 */ 2449static int 2450relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, 2451 int flags, RtldLockState *lockstate) 2452{ 2453 2454 if (obj->relocated) 2455 return (0); 2456 obj->relocated = true; 2457 if (obj != rtldobj) 2458 dbg("relocating \"%s\"", obj->path); 2459 2460 if (obj->symtab == NULL || obj->strtab == NULL || 2461 !(obj->valid_hash_sysv || obj->valid_hash_gnu)) { 2462 _rtld_error("%s: Shared object has no run-time symbol table", 2463 obj->path); 2464 return (-1); 2465 } 2466 2467 if (obj->textrel) { 2468 /* There are relocations to the write-protected text segment. */ 2469 if (mprotect(obj->mapbase, obj->textsize, 2470 PROT_READ|PROT_WRITE|PROT_EXEC) == -1) { 2471 _rtld_error("%s: Cannot write-enable text segment: %s", 2472 obj->path, rtld_strerror(errno)); 2473 return (-1); 2474 } 2475 } 2476 2477 /* Process the non-PLT non-IFUNC relocations. */ 2478 if (reloc_non_plt(obj, rtldobj, flags, lockstate)) 2479 return (-1); 2480 2481 if (obj->textrel) { /* Re-protected the text segment. */ 2482 if (mprotect(obj->mapbase, obj->textsize, 2483 PROT_READ|PROT_EXEC) == -1) { 2484 _rtld_error("%s: Cannot write-protect text segment: %s", 2485 obj->path, rtld_strerror(errno)); 2486 return (-1); 2487 } 2488 } 2489 2490 /* Set the special PLT or GOT entries. */ 2491 init_pltgot(obj); 2492 2493 /* Process the PLT relocations. */ 2494 if (reloc_plt(obj) == -1) 2495 return (-1); 2496 /* Relocate the jump slots if we are doing immediate binding. */ 2497 if (obj->bind_now || bind_now) 2498 if (reloc_jmpslots(obj, flags, lockstate) == -1) 2499 return (-1); 2500 2501 /* 2502 * Process the non-PLT IFUNC relocations. The relocations are 2503 * processed in two phases, because IFUNC resolvers may 2504 * reference other symbols, which must be readily processed 2505 * before resolvers are called. 2506 */ 2507 if (obj->non_plt_gnu_ifunc && 2508 reloc_non_plt(obj, rtldobj, flags | SYMLOOK_IFUNC, lockstate)) 2509 return (-1); 2510 2511 if (obj->relro_size > 0) { 2512 if (mprotect(obj->relro_page, obj->relro_size, 2513 PROT_READ) == -1) { 2514 _rtld_error("%s: Cannot enforce relro protection: %s", 2515 obj->path, rtld_strerror(errno)); 2516 return (-1); 2517 } 2518 } 2519 2520 /* 2521 * Set up the magic number and version in the Obj_Entry. These 2522 * were checked in the crt1.o from the original ElfKit, so we 2523 * set them for backward compatibility. 2524 */ 2525 obj->magic = RTLD_MAGIC; 2526 obj->version = RTLD_VERSION; 2527 2528 return (0); 2529} 2530 2531/* 2532 * Relocate newly-loaded shared objects. The argument is a pointer to 2533 * the Obj_Entry for the first such object. All objects from the first 2534 * to the end of the list of objects are relocated. Returns 0 on success, 2535 * or -1 on failure. 2536 */ 2537static int 2538relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj, 2539 int flags, RtldLockState *lockstate) 2540{ 2541 Obj_Entry *obj; 2542 int error; 2543 2544 for (error = 0, obj = first; obj != NULL; obj = obj->next) { 2545 error = relocate_object(obj, bind_now, rtldobj, flags, 2546 lockstate); 2547 if (error == -1) 2548 break; 2549 } 2550 return (error); 2551} 2552 2553/* 2554 * The handling of R_MACHINE_IRELATIVE relocations and jumpslots 2555 * referencing STT_GNU_IFUNC symbols is postponed till the other 2556 * relocations are done. The indirect functions specified as 2557 * ifunc are allowed to call other symbols, so we need to have 2558 * objects relocated before asking for resolution from indirects. 2559 * 2560 * The R_MACHINE_IRELATIVE slots are resolved in greedy fashion, 2561 * instead of the usual lazy handling of PLT slots. It is 2562 * consistent with how GNU does it. 2563 */ 2564static int 2565resolve_object_ifunc(Obj_Entry *obj, bool bind_now, int flags, 2566 RtldLockState *lockstate) 2567{ 2568 if (obj->irelative && reloc_iresolve(obj, lockstate) == -1) 2569 return (-1); 2570 if ((obj->bind_now || bind_now) && obj->gnu_ifunc && 2571 reloc_gnu_ifunc(obj, flags, lockstate) == -1) 2572 return (-1); 2573 return (0); 2574} 2575 2576static int 2577resolve_objects_ifunc(Obj_Entry *first, bool bind_now, int flags, 2578 RtldLockState *lockstate) 2579{ 2580 Obj_Entry *obj; 2581 2582 for (obj = first; obj != NULL; obj = obj->next) { 2583 if (resolve_object_ifunc(obj, bind_now, flags, lockstate) == -1) 2584 return (-1); 2585 } 2586 return (0); 2587} 2588 2589static int 2590initlist_objects_ifunc(Objlist *list, bool bind_now, int flags, 2591 RtldLockState *lockstate) 2592{ 2593 Objlist_Entry *elm; 2594 2595 STAILQ_FOREACH(elm, list, link) { 2596 if (resolve_object_ifunc(elm->obj, bind_now, flags, 2597 lockstate) == -1) 2598 return (-1); 2599 } 2600 return (0); 2601} 2602 2603/* 2604 * Cleanup procedure. It will be called (by the atexit mechanism) just 2605 * before the process exits. 2606 */ 2607static void 2608rtld_exit(void) 2609{ 2610 RtldLockState lockstate; 2611 2612 wlock_acquire(rtld_bind_lock, &lockstate); 2613 dbg("rtld_exit()"); 2614 objlist_call_fini(&list_fini, NULL, &lockstate); 2615 /* No need to remove the items from the list, since we are exiting. */ 2616 if (!libmap_disable) 2617 lm_fini(); 2618 lock_release(rtld_bind_lock, &lockstate); 2619} 2620 2621/* 2622 * Iterate over a search path, translate each element, and invoke the 2623 * callback on the result. 2624 */ 2625static void * 2626path_enumerate(const char *path, path_enum_proc callback, void *arg) 2627{ 2628 const char *trans; 2629 if (path == NULL) 2630 return (NULL); 2631 2632 path += strspn(path, ":;"); 2633 while (*path != '\0') { 2634 size_t len; 2635 char *res; 2636 2637 len = strcspn(path, ":;"); 2638 trans = lm_findn(NULL, path, len); 2639 if (trans) 2640 res = callback(trans, strlen(trans), arg); 2641 else 2642 res = callback(path, len, arg); 2643 2644 if (res != NULL) 2645 return (res); 2646 2647 path += len; 2648 path += strspn(path, ":;"); 2649 } 2650 2651 return (NULL); 2652} 2653 2654struct try_library_args { 2655 const char *name; 2656 size_t namelen; 2657 char *buffer; 2658 size_t buflen; 2659}; 2660 2661static void * 2662try_library_path(const char *dir, size_t dirlen, void *param) 2663{ 2664 struct try_library_args *arg; 2665 2666 arg = param; 2667 if (*dir == '/' || trust) { 2668 char *pathname; 2669 2670 if (dirlen + 1 + arg->namelen + 1 > arg->buflen) 2671 return (NULL); 2672 2673 pathname = arg->buffer; 2674 strncpy(pathname, dir, dirlen); 2675 pathname[dirlen] = '/'; 2676 strcpy(pathname + dirlen + 1, arg->name); 2677 2678 dbg(" Trying \"%s\"", pathname); 2679 if (access(pathname, F_OK) == 0) { /* We found it */ 2680 pathname = xmalloc(dirlen + 1 + arg->namelen + 1); 2681 strcpy(pathname, arg->buffer); 2682 return (pathname); 2683 } 2684 } 2685 return (NULL); 2686} 2687 2688static char * 2689search_library_path(const char *name, const char *path) 2690{ 2691 char *p; 2692 struct try_library_args arg; 2693 2694 if (path == NULL) 2695 return NULL; 2696 2697 arg.name = name; 2698 arg.namelen = strlen(name); 2699 arg.buffer = xmalloc(PATH_MAX); 2700 arg.buflen = PATH_MAX; 2701 2702 p = path_enumerate(path, try_library_path, &arg); 2703 2704 free(arg.buffer); 2705 2706 return (p); 2707} 2708 2709int 2710dlclose(void *handle) 2711{ 2712 Obj_Entry *root; 2713 RtldLockState lockstate; 2714 2715 wlock_acquire(rtld_bind_lock, &lockstate); 2716 root = dlcheck(handle); 2717 if (root == NULL) { 2718 lock_release(rtld_bind_lock, &lockstate); 2719 return -1; 2720 } 2721 LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount, 2722 root->path); 2723 2724 /* Unreference the object and its dependencies. */ 2725 root->dl_refcount--; 2726 2727 if (root->refcount == 1) { 2728 /* 2729 * The object will be no longer referenced, so we must unload it. 2730 * First, call the fini functions. 2731 */ 2732 objlist_call_fini(&list_fini, root, &lockstate); 2733 2734 unref_dag(root); 2735 2736 /* Finish cleaning up the newly-unreferenced objects. */ 2737 GDB_STATE(RT_DELETE,&root->linkmap); 2738 unload_object(root); 2739 GDB_STATE(RT_CONSISTENT,NULL); 2740 } else 2741 unref_dag(root); 2742 2743 LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL); 2744 lock_release(rtld_bind_lock, &lockstate); 2745 return 0; 2746} 2747 2748char * 2749dlerror(void) 2750{ 2751 char *msg = error_message; 2752 error_message = NULL; 2753 return msg; 2754} 2755 2756/* 2757 * This function is deprecated and has no effect. 2758 */ 2759void 2760dllockinit(void *context, 2761 void *(*lock_create)(void *context), 2762 void (*rlock_acquire)(void *lock), 2763 void (*wlock_acquire)(void *lock), 2764 void (*lock_release)(void *lock), 2765 void (*lock_destroy)(void *lock), 2766 void (*context_destroy)(void *context)) 2767{ 2768 static void *cur_context; 2769 static void (*cur_context_destroy)(void *); 2770 2771 /* Just destroy the context from the previous call, if necessary. */ 2772 if (cur_context_destroy != NULL) 2773 cur_context_destroy(cur_context); 2774 cur_context = context; 2775 cur_context_destroy = context_destroy; 2776} 2777 2778void * 2779dlopen(const char *name, int mode) 2780{ 2781 2782 return (rtld_dlopen(name, -1, mode)); 2783} 2784 2785void * 2786fdlopen(int fd, int mode) 2787{ 2788 2789 return (rtld_dlopen(NULL, fd, mode)); 2790} 2791 2792static void * 2793rtld_dlopen(const char *name, int fd, int mode) 2794{ 2795 RtldLockState lockstate; 2796 int lo_flags; 2797 2798 LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name); 2799 ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1"; 2800 if (ld_tracing != NULL) { 2801 rlock_acquire(rtld_bind_lock, &lockstate); 2802 if (sigsetjmp(lockstate.env, 0) != 0) 2803 lock_upgrade(rtld_bind_lock, &lockstate); 2804 environ = (char **)*get_program_var_addr("environ", &lockstate); 2805 lock_release(rtld_bind_lock, &lockstate); 2806 } 2807 lo_flags = RTLD_LO_DLOPEN; 2808 if (mode & RTLD_NODELETE) 2809 lo_flags |= RTLD_LO_NODELETE; 2810 if (mode & RTLD_NOLOAD) 2811 lo_flags |= RTLD_LO_NOLOAD; 2812 if (ld_tracing != NULL) 2813 lo_flags |= RTLD_LO_TRACE; 2814 2815 return (dlopen_object(name, fd, obj_main, lo_flags, 2816 mode & (RTLD_MODEMASK | RTLD_GLOBAL), NULL)); 2817} 2818 2819static void 2820dlopen_cleanup(Obj_Entry *obj) 2821{ 2822 2823 obj->dl_refcount--; 2824 unref_dag(obj); 2825 if (obj->refcount == 0) 2826 unload_object(obj); 2827} 2828 2829static Obj_Entry * 2830dlopen_object(const char *name, int fd, Obj_Entry *refobj, int lo_flags, 2831 int mode, RtldLockState *lockstate) 2832{ 2833 Obj_Entry **old_obj_tail; 2834 Obj_Entry *obj; 2835 Objlist initlist; 2836 RtldLockState mlockstate; 2837 int result; 2838 2839 objlist_init(&initlist); 2840 2841 if (lockstate == NULL && !(lo_flags & RTLD_LO_EARLY)) { 2842 wlock_acquire(rtld_bind_lock, &mlockstate); 2843 lockstate = &mlockstate; 2844 } 2845 GDB_STATE(RT_ADD,NULL); 2846 2847 old_obj_tail = obj_tail; 2848 obj = NULL; 2849 if (name == NULL && fd == -1) { 2850 obj = obj_main; 2851 obj->refcount++; 2852 } else { 2853 obj = load_object(name, fd, refobj, lo_flags); 2854 } 2855 2856 if (obj) { 2857 obj->dl_refcount++; 2858 if (mode & RTLD_GLOBAL && objlist_find(&list_global, obj) == NULL) 2859 objlist_push_tail(&list_global, obj); 2860 if (*old_obj_tail != NULL) { /* We loaded something new. */ 2861 assert(*old_obj_tail == obj); 2862 result = load_needed_objects(obj, 2863 lo_flags & (RTLD_LO_DLOPEN | RTLD_LO_EARLY)); 2864 init_dag(obj); 2865 ref_dag(obj); 2866 if (result != -1) 2867 result = rtld_verify_versions(&obj->dagmembers); 2868 if (result != -1 && ld_tracing) 2869 goto trace; 2870 if (result == -1 || relocate_object_dag(obj, 2871 (mode & RTLD_MODEMASK) == RTLD_NOW, &obj_rtld, 2872 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 2873 lockstate) == -1) { 2874 dlopen_cleanup(obj); 2875 obj = NULL; 2876 } else if (lo_flags & RTLD_LO_EARLY) { 2877 /* 2878 * Do not call the init functions for early loaded 2879 * filtees. The image is still not initialized enough 2880 * for them to work. 2881 * 2882 * Our object is found by the global object list and 2883 * will be ordered among all init calls done right 2884 * before transferring control to main. 2885 */ 2886 } else { 2887 /* Make list of init functions to call. */ 2888 initlist_add_objects(obj, &obj->next, &initlist); 2889 } 2890 /* 2891 * Process all no_delete objects here, given them own 2892 * DAGs to prevent their dependencies from being unloaded. 2893 * This has to be done after we have loaded all of the 2894 * dependencies, so that we do not miss any. 2895 */ 2896 if (obj != NULL) 2897 process_nodelete(obj); 2898 } else { 2899 /* 2900 * Bump the reference counts for objects on this DAG. If 2901 * this is the first dlopen() call for the object that was 2902 * already loaded as a dependency, initialize the dag 2903 * starting at it. 2904 */ 2905 init_dag(obj); 2906 ref_dag(obj); 2907 2908 if ((lo_flags & RTLD_LO_TRACE) != 0) 2909 goto trace; 2910 } 2911 if (obj != NULL && ((lo_flags & RTLD_LO_NODELETE) != 0 || 2912 obj->z_nodelete) && !obj->ref_nodel) { 2913 dbg("obj %s nodelete", obj->path); 2914 ref_dag(obj); 2915 obj->z_nodelete = obj->ref_nodel = true; 2916 } 2917 } 2918 2919 LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0, 2920 name); 2921 GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL); 2922 2923 if (!(lo_flags & RTLD_LO_EARLY)) { 2924 map_stacks_exec(lockstate); 2925 } 2926 2927 if (initlist_objects_ifunc(&initlist, (mode & RTLD_MODEMASK) == RTLD_NOW, 2928 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 2929 lockstate) == -1) { 2930 objlist_clear(&initlist); 2931 dlopen_cleanup(obj); 2932 if (lockstate == &mlockstate) 2933 lock_release(rtld_bind_lock, lockstate); 2934 return (NULL); 2935 } 2936 2937 if (!(lo_flags & RTLD_LO_EARLY)) { 2938 /* Call the init functions. */ 2939 objlist_call_init(&initlist, lockstate); 2940 } 2941 objlist_clear(&initlist); 2942 if (lockstate == &mlockstate) 2943 lock_release(rtld_bind_lock, lockstate); 2944 return obj; 2945trace: 2946 trace_loaded_objects(obj); 2947 if (lockstate == &mlockstate) 2948 lock_release(rtld_bind_lock, lockstate); 2949 exit(0); 2950} 2951 2952static void * 2953do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve, 2954 int flags) 2955{ 2956 DoneList donelist; 2957 const Obj_Entry *obj, *defobj; 2958 const Elf_Sym *def; 2959 SymLook req; 2960 RtldLockState lockstate; 2961#ifndef __ia64__ 2962 tls_index ti; 2963#endif 2964 int res; 2965 2966 def = NULL; 2967 defobj = NULL; 2968 symlook_init(&req, name); 2969 req.ventry = ve; 2970 req.flags = flags | SYMLOOK_IN_PLT; 2971 req.lockstate = &lockstate; 2972 2973 rlock_acquire(rtld_bind_lock, &lockstate); 2974 if (sigsetjmp(lockstate.env, 0) != 0) 2975 lock_upgrade(rtld_bind_lock, &lockstate); 2976 if (handle == NULL || handle == RTLD_NEXT || 2977 handle == RTLD_DEFAULT || handle == RTLD_SELF) { 2978 2979 if ((obj = obj_from_addr(retaddr)) == NULL) { 2980 _rtld_error("Cannot determine caller's shared object"); 2981 lock_release(rtld_bind_lock, &lockstate); 2982 return NULL; 2983 } 2984 if (handle == NULL) { /* Just the caller's shared object. */ 2985 res = symlook_obj(&req, obj); 2986 if (res == 0) { 2987 def = req.sym_out; 2988 defobj = req.defobj_out; 2989 } 2990 } else if (handle == RTLD_NEXT || /* Objects after caller's */ 2991 handle == RTLD_SELF) { /* ... caller included */ 2992 if (handle == RTLD_NEXT) 2993 obj = obj->next; 2994 for (; obj != NULL; obj = obj->next) { 2995 res = symlook_obj(&req, obj); 2996 if (res == 0) { 2997 if (def == NULL || 2998 ELF_ST_BIND(req.sym_out->st_info) != STB_WEAK) { 2999 def = req.sym_out; 3000 defobj = req.defobj_out; 3001 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 3002 break; 3003 } 3004 } 3005 } 3006 /* 3007 * Search the dynamic linker itself, and possibly resolve the 3008 * symbol from there. This is how the application links to 3009 * dynamic linker services such as dlopen. 3010 */ 3011 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 3012 res = symlook_obj(&req, &obj_rtld); 3013 if (res == 0) { 3014 def = req.sym_out; 3015 defobj = req.defobj_out; 3016 } 3017 } 3018 } else { 3019 assert(handle == RTLD_DEFAULT); 3020 res = symlook_default(&req, obj); 3021 if (res == 0) { 3022 defobj = req.defobj_out; 3023 def = req.sym_out; 3024 } 3025 } 3026 } else { 3027 if ((obj = dlcheck(handle)) == NULL) { 3028 lock_release(rtld_bind_lock, &lockstate); 3029 return NULL; 3030 } 3031 3032 donelist_init(&donelist); 3033 if (obj->mainprog) { 3034 /* Handle obtained by dlopen(NULL, ...) implies global scope. */ 3035 res = symlook_global(&req, &donelist); 3036 if (res == 0) { 3037 def = req.sym_out; 3038 defobj = req.defobj_out; 3039 } 3040 /* 3041 * Search the dynamic linker itself, and possibly resolve the 3042 * symbol from there. This is how the application links to 3043 * dynamic linker services such as dlopen. 3044 */ 3045 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 3046 res = symlook_obj(&req, &obj_rtld); 3047 if (res == 0) { 3048 def = req.sym_out; 3049 defobj = req.defobj_out; 3050 } 3051 } 3052 } 3053 else { 3054 /* Search the whole DAG rooted at the given object. */ 3055 res = symlook_list(&req, &obj->dagmembers, &donelist); 3056 if (res == 0) { 3057 def = req.sym_out; 3058 defobj = req.defobj_out; 3059 } 3060 } 3061 } 3062 3063 if (def != NULL) { 3064 lock_release(rtld_bind_lock, &lockstate); 3065 3066 /* 3067 * The value required by the caller is derived from the value 3068 * of the symbol. For the ia64 architecture, we need to 3069 * construct a function descriptor which the caller can use to 3070 * call the function with the right 'gp' value. For other 3071 * architectures and for non-functions, the value is simply 3072 * the relocated value of the symbol. 3073 */ 3074 if (ELF_ST_TYPE(def->st_info) == STT_FUNC) 3075 return (make_function_pointer(def, defobj)); 3076 else if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 3077 return (rtld_resolve_ifunc(defobj, def)); 3078 else if (ELF_ST_TYPE(def->st_info) == STT_TLS) { 3079#ifdef __ia64__ 3080 return (__tls_get_addr(defobj->tlsindex, def->st_value)); 3081#else 3082 ti.ti_module = defobj->tlsindex; 3083 ti.ti_offset = def->st_value; 3084 return (__tls_get_addr(&ti)); 3085#endif 3086 } else 3087 return (defobj->relocbase + def->st_value); 3088 } 3089 3090 _rtld_error("Undefined symbol \"%s\"", name); 3091 lock_release(rtld_bind_lock, &lockstate); 3092 return NULL; 3093} 3094 3095void * 3096dlsym(void *handle, const char *name) 3097{ 3098 return do_dlsym(handle, name, __builtin_return_address(0), NULL, 3099 SYMLOOK_DLSYM); 3100} 3101 3102dlfunc_t 3103dlfunc(void *handle, const char *name) 3104{ 3105 union { 3106 void *d; 3107 dlfunc_t f; 3108 } rv; 3109 3110 rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL, 3111 SYMLOOK_DLSYM); 3112 return (rv.f); 3113} 3114 3115void * 3116dlvsym(void *handle, const char *name, const char *version) 3117{ 3118 Ver_Entry ventry; 3119 3120 ventry.name = version; 3121 ventry.file = NULL; 3122 ventry.hash = elf_hash(version); 3123 ventry.flags= 0; 3124 return do_dlsym(handle, name, __builtin_return_address(0), &ventry, 3125 SYMLOOK_DLSYM); 3126} 3127 3128int 3129_rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info) 3130{ 3131 const Obj_Entry *obj; 3132 RtldLockState lockstate; 3133 3134 rlock_acquire(rtld_bind_lock, &lockstate); 3135 obj = obj_from_addr(addr); 3136 if (obj == NULL) { 3137 _rtld_error("No shared object contains address"); 3138 lock_release(rtld_bind_lock, &lockstate); 3139 return (0); 3140 } 3141 rtld_fill_dl_phdr_info(obj, phdr_info); 3142 lock_release(rtld_bind_lock, &lockstate); 3143 return (1); 3144} 3145 3146int 3147dladdr(const void *addr, Dl_info *info) 3148{ 3149 const Obj_Entry *obj; 3150 const Elf_Sym *def; 3151 void *symbol_addr; 3152 unsigned long symoffset; 3153 RtldLockState lockstate; 3154 3155 rlock_acquire(rtld_bind_lock, &lockstate); 3156 obj = obj_from_addr(addr); 3157 if (obj == NULL) { 3158 _rtld_error("No shared object contains address"); 3159 lock_release(rtld_bind_lock, &lockstate); 3160 return 0; 3161 } 3162 info->dli_fname = obj->path; 3163 info->dli_fbase = obj->mapbase; 3164 info->dli_saddr = (void *)0; 3165 info->dli_sname = NULL; 3166 3167 /* 3168 * Walk the symbol list looking for the symbol whose address is 3169 * closest to the address sent in. 3170 */ 3171 for (symoffset = 0; symoffset < obj->dynsymcount; symoffset++) { 3172 def = obj->symtab + symoffset; 3173 3174 /* 3175 * For skip the symbol if st_shndx is either SHN_UNDEF or 3176 * SHN_COMMON. 3177 */ 3178 if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON) 3179 continue; 3180 3181 /* 3182 * If the symbol is greater than the specified address, or if it 3183 * is further away from addr than the current nearest symbol, 3184 * then reject it. 3185 */ 3186 symbol_addr = obj->relocbase + def->st_value; 3187 if (symbol_addr > addr || symbol_addr < info->dli_saddr) 3188 continue; 3189 3190 /* Update our idea of the nearest symbol. */ 3191 info->dli_sname = obj->strtab + def->st_name; 3192 info->dli_saddr = symbol_addr; 3193 3194 /* Exact match? */ 3195 if (info->dli_saddr == addr) 3196 break; 3197 } 3198 lock_release(rtld_bind_lock, &lockstate); 3199 return 1; 3200} 3201 3202int 3203dlinfo(void *handle, int request, void *p) 3204{ 3205 const Obj_Entry *obj; 3206 RtldLockState lockstate; 3207 int error; 3208 3209 rlock_acquire(rtld_bind_lock, &lockstate); 3210 3211 if (handle == NULL || handle == RTLD_SELF) { 3212 void *retaddr; 3213 3214 retaddr = __builtin_return_address(0); /* __GNUC__ only */ 3215 if ((obj = obj_from_addr(retaddr)) == NULL) 3216 _rtld_error("Cannot determine caller's shared object"); 3217 } else 3218 obj = dlcheck(handle); 3219 3220 if (obj == NULL) { 3221 lock_release(rtld_bind_lock, &lockstate); 3222 return (-1); 3223 } 3224 3225 error = 0; 3226 switch (request) { 3227 case RTLD_DI_LINKMAP: 3228 *((struct link_map const **)p) = &obj->linkmap; 3229 break; 3230 case RTLD_DI_ORIGIN: 3231 error = rtld_dirname(obj->path, p); 3232 break; 3233 3234 case RTLD_DI_SERINFOSIZE: 3235 case RTLD_DI_SERINFO: 3236 error = do_search_info(obj, request, (struct dl_serinfo *)p); 3237 break; 3238 3239 default: 3240 _rtld_error("Invalid request %d passed to dlinfo()", request); 3241 error = -1; 3242 } 3243 3244 lock_release(rtld_bind_lock, &lockstate); 3245 3246 return (error); 3247} 3248 3249static void 3250rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info) 3251{ 3252 3253 phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase; 3254 phdr_info->dlpi_name = obj->path; 3255 phdr_info->dlpi_phdr = obj->phdr; 3256 phdr_info->dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]); 3257 phdr_info->dlpi_tls_modid = obj->tlsindex; 3258 phdr_info->dlpi_tls_data = obj->tlsinit; 3259 phdr_info->dlpi_adds = obj_loads; 3260 phdr_info->dlpi_subs = obj_loads - obj_count; 3261} 3262 3263int 3264dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param) 3265{ 3266 struct dl_phdr_info phdr_info; 3267 const Obj_Entry *obj; 3268 RtldLockState bind_lockstate, phdr_lockstate; 3269 int error; 3270 3271 wlock_acquire(rtld_phdr_lock, &phdr_lockstate); 3272 rlock_acquire(rtld_bind_lock, &bind_lockstate); 3273 3274 error = 0; 3275 3276 for (obj = obj_list; obj != NULL; obj = obj->next) { 3277 rtld_fill_dl_phdr_info(obj, &phdr_info); 3278 if ((error = callback(&phdr_info, sizeof phdr_info, param)) != 0) 3279 break; 3280 3281 } 3282 lock_release(rtld_bind_lock, &bind_lockstate); 3283 lock_release(rtld_phdr_lock, &phdr_lockstate); 3284 3285 return (error); 3286} 3287 3288static void * 3289fill_search_info(const char *dir, size_t dirlen, void *param) 3290{ 3291 struct fill_search_info_args *arg; 3292 3293 arg = param; 3294 3295 if (arg->request == RTLD_DI_SERINFOSIZE) { 3296 arg->serinfo->dls_cnt ++; 3297 arg->serinfo->dls_size += sizeof(struct dl_serpath) + dirlen + 1; 3298 } else { 3299 struct dl_serpath *s_entry; 3300 3301 s_entry = arg->serpath; 3302 s_entry->dls_name = arg->strspace; 3303 s_entry->dls_flags = arg->flags; 3304 3305 strncpy(arg->strspace, dir, dirlen); 3306 arg->strspace[dirlen] = '\0'; 3307 3308 arg->strspace += dirlen + 1; 3309 arg->serpath++; 3310 } 3311 3312 return (NULL); 3313} 3314 3315static int 3316do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info) 3317{ 3318 struct dl_serinfo _info; 3319 struct fill_search_info_args args; 3320 3321 args.request = RTLD_DI_SERINFOSIZE; 3322 args.serinfo = &_info; 3323 3324 _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 3325 _info.dls_cnt = 0; 3326 3327 path_enumerate(obj->rpath, fill_search_info, &args); 3328 path_enumerate(ld_library_path, fill_search_info, &args); 3329 path_enumerate(obj->runpath, fill_search_info, &args); 3330 path_enumerate(gethints(obj->z_nodeflib), fill_search_info, &args); 3331 if (!obj->z_nodeflib) 3332 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args); 3333 3334 3335 if (request == RTLD_DI_SERINFOSIZE) { 3336 info->dls_size = _info.dls_size; 3337 info->dls_cnt = _info.dls_cnt; 3338 return (0); 3339 } 3340 3341 if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) { 3342 _rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()"); 3343 return (-1); 3344 } 3345 3346 args.request = RTLD_DI_SERINFO; 3347 args.serinfo = info; 3348 args.serpath = &info->dls_serpath[0]; 3349 args.strspace = (char *)&info->dls_serpath[_info.dls_cnt]; 3350 3351 args.flags = LA_SER_RUNPATH; 3352 if (path_enumerate(obj->rpath, fill_search_info, &args) != NULL) 3353 return (-1); 3354 3355 args.flags = LA_SER_LIBPATH; 3356 if (path_enumerate(ld_library_path, fill_search_info, &args) != NULL) 3357 return (-1); 3358 3359 args.flags = LA_SER_RUNPATH; 3360 if (path_enumerate(obj->runpath, fill_search_info, &args) != NULL) 3361 return (-1); 3362 3363 args.flags = LA_SER_CONFIG; 3364 if (path_enumerate(gethints(obj->z_nodeflib), fill_search_info, &args) 3365 != NULL) 3366 return (-1); 3367 3368 args.flags = LA_SER_DEFAULT; 3369 if (!obj->z_nodeflib && 3370 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args) != NULL) 3371 return (-1); 3372 return (0); 3373} 3374 3375static int 3376rtld_dirname(const char *path, char *bname) 3377{ 3378 const char *endp; 3379 3380 /* Empty or NULL string gets treated as "." */ 3381 if (path == NULL || *path == '\0') { 3382 bname[0] = '.'; 3383 bname[1] = '\0'; 3384 return (0); 3385 } 3386 3387 /* Strip trailing slashes */ 3388 endp = path + strlen(path) - 1; 3389 while (endp > path && *endp == '/') 3390 endp--; 3391 3392 /* Find the start of the dir */ 3393 while (endp > path && *endp != '/') 3394 endp--; 3395 3396 /* Either the dir is "/" or there are no slashes */ 3397 if (endp == path) { 3398 bname[0] = *endp == '/' ? '/' : '.'; 3399 bname[1] = '\0'; 3400 return (0); 3401 } else { 3402 do { 3403 endp--; 3404 } while (endp > path && *endp == '/'); 3405 } 3406 3407 if (endp - path + 2 > PATH_MAX) 3408 { 3409 _rtld_error("Filename is too long: %s", path); 3410 return(-1); 3411 } 3412 3413 strncpy(bname, path, endp - path + 1); 3414 bname[endp - path + 1] = '\0'; 3415 return (0); 3416} 3417 3418static int 3419rtld_dirname_abs(const char *path, char *base) 3420{ 3421 char base_rel[PATH_MAX]; 3422 3423 if (rtld_dirname(path, base) == -1) 3424 return (-1); 3425 if (base[0] == '/') 3426 return (0); 3427 if (getcwd(base_rel, sizeof(base_rel)) == NULL || 3428 strlcat(base_rel, "/", sizeof(base_rel)) >= sizeof(base_rel) || 3429 strlcat(base_rel, base, sizeof(base_rel)) >= sizeof(base_rel)) 3430 return (-1); 3431 strcpy(base, base_rel); 3432 return (0); 3433} 3434 3435static void 3436linkmap_add(Obj_Entry *obj) 3437{ 3438 struct link_map *l = &obj->linkmap; 3439 struct link_map *prev; 3440 3441 obj->linkmap.l_name = obj->path; 3442 obj->linkmap.l_addr = obj->mapbase; 3443 obj->linkmap.l_ld = obj->dynamic; 3444#ifdef __mips__ 3445 /* GDB needs load offset on MIPS to use the symbols */ 3446 obj->linkmap.l_offs = obj->relocbase; 3447#endif 3448 3449 if (r_debug.r_map == NULL) { 3450 r_debug.r_map = l; 3451 return; 3452 } 3453 3454 /* 3455 * Scan to the end of the list, but not past the entry for the 3456 * dynamic linker, which we want to keep at the very end. 3457 */ 3458 for (prev = r_debug.r_map; 3459 prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap; 3460 prev = prev->l_next) 3461 ; 3462 3463 /* Link in the new entry. */ 3464 l->l_prev = prev; 3465 l->l_next = prev->l_next; 3466 if (l->l_next != NULL) 3467 l->l_next->l_prev = l; 3468 prev->l_next = l; 3469} 3470 3471static void 3472linkmap_delete(Obj_Entry *obj) 3473{ 3474 struct link_map *l = &obj->linkmap; 3475 3476 if (l->l_prev == NULL) { 3477 if ((r_debug.r_map = l->l_next) != NULL) 3478 l->l_next->l_prev = NULL; 3479 return; 3480 } 3481 3482 if ((l->l_prev->l_next = l->l_next) != NULL) 3483 l->l_next->l_prev = l->l_prev; 3484} 3485 3486/* 3487 * Function for the debugger to set a breakpoint on to gain control. 3488 * 3489 * The two parameters allow the debugger to easily find and determine 3490 * what the runtime loader is doing and to whom it is doing it. 3491 * 3492 * When the loadhook trap is hit (r_debug_state, set at program 3493 * initialization), the arguments can be found on the stack: 3494 * 3495 * +8 struct link_map *m 3496 * +4 struct r_debug *rd 3497 * +0 RetAddr 3498 */ 3499void 3500r_debug_state(struct r_debug* rd, struct link_map *m) 3501{ 3502 /* 3503 * The following is a hack to force the compiler to emit calls to 3504 * this function, even when optimizing. If the function is empty, 3505 * the compiler is not obliged to emit any code for calls to it, 3506 * even when marked __noinline. However, gdb depends on those 3507 * calls being made. 3508 */ 3509 __compiler_membar(); 3510} 3511 3512/* 3513 * A function called after init routines have completed. This can be used to 3514 * break before a program's entry routine is called, and can be used when 3515 * main is not available in the symbol table. 3516 */ 3517void 3518_r_debug_postinit(struct link_map *m) 3519{ 3520 3521 /* See r_debug_state(). */ 3522 __compiler_membar(); 3523} 3524 3525/* 3526 * Get address of the pointer variable in the main program. 3527 * Prefer non-weak symbol over the weak one. 3528 */ 3529static const void ** 3530get_program_var_addr(const char *name, RtldLockState *lockstate) 3531{ 3532 SymLook req; 3533 DoneList donelist; 3534 3535 symlook_init(&req, name); 3536 req.lockstate = lockstate; 3537 donelist_init(&donelist); 3538 if (symlook_global(&req, &donelist) != 0) 3539 return (NULL); 3540 if (ELF_ST_TYPE(req.sym_out->st_info) == STT_FUNC) 3541 return ((const void **)make_function_pointer(req.sym_out, 3542 req.defobj_out)); 3543 else if (ELF_ST_TYPE(req.sym_out->st_info) == STT_GNU_IFUNC) 3544 return ((const void **)rtld_resolve_ifunc(req.defobj_out, req.sym_out)); 3545 else 3546 return ((const void **)(req.defobj_out->relocbase + 3547 req.sym_out->st_value)); 3548} 3549 3550/* 3551 * Set a pointer variable in the main program to the given value. This 3552 * is used to set key variables such as "environ" before any of the 3553 * init functions are called. 3554 */ 3555static void 3556set_program_var(const char *name, const void *value) 3557{ 3558 const void **addr; 3559 3560 if ((addr = get_program_var_addr(name, NULL)) != NULL) { 3561 dbg("\"%s\": *%p <-- %p", name, addr, value); 3562 *addr = value; 3563 } 3564} 3565 3566/* 3567 * Search the global objects, including dependencies and main object, 3568 * for the given symbol. 3569 */ 3570static int 3571symlook_global(SymLook *req, DoneList *donelist) 3572{ 3573 SymLook req1; 3574 const Objlist_Entry *elm; 3575 int res; 3576 3577 symlook_init_from_req(&req1, req); 3578 3579 /* Search all objects loaded at program start up. */ 3580 if (req->defobj_out == NULL || 3581 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 3582 res = symlook_list(&req1, &list_main, donelist); 3583 if (res == 0 && (req->defobj_out == NULL || 3584 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 3585 req->sym_out = req1.sym_out; 3586 req->defobj_out = req1.defobj_out; 3587 assert(req->defobj_out != NULL); 3588 } 3589 } 3590 3591 /* Search all DAGs whose roots are RTLD_GLOBAL objects. */ 3592 STAILQ_FOREACH(elm, &list_global, link) { 3593 if (req->defobj_out != NULL && 3594 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK) 3595 break; 3596 res = symlook_list(&req1, &elm->obj->dagmembers, donelist); 3597 if (res == 0 && (req->defobj_out == NULL || 3598 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 3599 req->sym_out = req1.sym_out; 3600 req->defobj_out = req1.defobj_out; 3601 assert(req->defobj_out != NULL); 3602 } 3603 } 3604 3605 return (req->sym_out != NULL ? 0 : ESRCH); 3606} 3607 3608/* 3609 * Given a symbol name in a referencing object, find the corresponding 3610 * definition of the symbol. Returns a pointer to the symbol, or NULL if 3611 * no definition was found. Returns a pointer to the Obj_Entry of the 3612 * defining object via the reference parameter DEFOBJ_OUT. 3613 */ 3614static int 3615symlook_default(SymLook *req, const Obj_Entry *refobj) 3616{ 3617 DoneList donelist; 3618 const Objlist_Entry *elm; 3619 SymLook req1; 3620 int res; 3621 3622 donelist_init(&donelist); 3623 symlook_init_from_req(&req1, req); 3624 3625 /* Look first in the referencing object if linked symbolically. */ 3626 if (refobj->symbolic && !donelist_check(&donelist, refobj)) { 3627 res = symlook_obj(&req1, refobj); 3628 if (res == 0) { 3629 req->sym_out = req1.sym_out; 3630 req->defobj_out = req1.defobj_out; 3631 assert(req->defobj_out != NULL); 3632 } 3633 } 3634 3635 symlook_global(req, &donelist); 3636 3637 /* Search all dlopened DAGs containing the referencing object. */ 3638 STAILQ_FOREACH(elm, &refobj->dldags, link) { 3639 if (req->sym_out != NULL && 3640 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK) 3641 break; 3642 res = symlook_list(&req1, &elm->obj->dagmembers, &donelist); 3643 if (res == 0 && (req->sym_out == NULL || 3644 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 3645 req->sym_out = req1.sym_out; 3646 req->defobj_out = req1.defobj_out; 3647 assert(req->defobj_out != NULL); 3648 } 3649 } 3650 3651 /* 3652 * Search the dynamic linker itself, and possibly resolve the 3653 * symbol from there. This is how the application links to 3654 * dynamic linker services such as dlopen. 3655 */ 3656 if (req->sym_out == NULL || 3657 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 3658 res = symlook_obj(&req1, &obj_rtld); 3659 if (res == 0) { 3660 req->sym_out = req1.sym_out; 3661 req->defobj_out = req1.defobj_out; 3662 assert(req->defobj_out != NULL); 3663 } 3664 } 3665 3666 return (req->sym_out != NULL ? 0 : ESRCH); 3667} 3668 3669static int 3670symlook_list(SymLook *req, const Objlist *objlist, DoneList *dlp) 3671{ 3672 const Elf_Sym *def; 3673 const Obj_Entry *defobj; 3674 const Objlist_Entry *elm; 3675 SymLook req1; 3676 int res; 3677 3678 def = NULL; 3679 defobj = NULL; 3680 STAILQ_FOREACH(elm, objlist, link) { 3681 if (donelist_check(dlp, elm->obj)) 3682 continue; 3683 symlook_init_from_req(&req1, req); 3684 if ((res = symlook_obj(&req1, elm->obj)) == 0) { 3685 if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) { 3686 def = req1.sym_out; 3687 defobj = req1.defobj_out; 3688 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 3689 break; 3690 } 3691 } 3692 } 3693 if (def != NULL) { 3694 req->sym_out = def; 3695 req->defobj_out = defobj; 3696 return (0); 3697 } 3698 return (ESRCH); 3699} 3700 3701/* 3702 * Search the chain of DAGS cointed to by the given Needed_Entry 3703 * for a symbol of the given name. Each DAG is scanned completely 3704 * before advancing to the next one. Returns a pointer to the symbol, 3705 * or NULL if no definition was found. 3706 */ 3707static int 3708symlook_needed(SymLook *req, const Needed_Entry *needed, DoneList *dlp) 3709{ 3710 const Elf_Sym *def; 3711 const Needed_Entry *n; 3712 const Obj_Entry *defobj; 3713 SymLook req1; 3714 int res; 3715 3716 def = NULL; 3717 defobj = NULL; 3718 symlook_init_from_req(&req1, req); 3719 for (n = needed; n != NULL; n = n->next) { 3720 if (n->obj == NULL || 3721 (res = symlook_list(&req1, &n->obj->dagmembers, dlp)) != 0) 3722 continue; 3723 if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) { 3724 def = req1.sym_out; 3725 defobj = req1.defobj_out; 3726 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 3727 break; 3728 } 3729 } 3730 if (def != NULL) { 3731 req->sym_out = def; 3732 req->defobj_out = defobj; 3733 return (0); 3734 } 3735 return (ESRCH); 3736} 3737 3738/* 3739 * Search the symbol table of a single shared object for a symbol of 3740 * the given name and version, if requested. Returns a pointer to the 3741 * symbol, or NULL if no definition was found. If the object is 3742 * filter, return filtered symbol from filtee. 3743 * 3744 * The symbol's hash value is passed in for efficiency reasons; that 3745 * eliminates many recomputations of the hash value. 3746 */ 3747int 3748symlook_obj(SymLook *req, const Obj_Entry *obj) 3749{ 3750 DoneList donelist; 3751 SymLook req1; 3752 int flags, res, mres; 3753 3754 /* 3755 * If there is at least one valid hash at this point, we prefer to 3756 * use the faster GNU version if available. 3757 */ 3758 if (obj->valid_hash_gnu) 3759 mres = symlook_obj1_gnu(req, obj); 3760 else if (obj->valid_hash_sysv) 3761 mres = symlook_obj1_sysv(req, obj); 3762 else 3763 return (EINVAL); 3764 3765 if (mres == 0) { 3766 if (obj->needed_filtees != NULL) { 3767 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; 3768 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 3769 donelist_init(&donelist); 3770 symlook_init_from_req(&req1, req); 3771 res = symlook_needed(&req1, obj->needed_filtees, &donelist); 3772 if (res == 0) { 3773 req->sym_out = req1.sym_out; 3774 req->defobj_out = req1.defobj_out; 3775 } 3776 return (res); 3777 } 3778 if (obj->needed_aux_filtees != NULL) { 3779 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; 3780 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 3781 donelist_init(&donelist); 3782 symlook_init_from_req(&req1, req); 3783 res = symlook_needed(&req1, obj->needed_aux_filtees, &donelist); 3784 if (res == 0) { 3785 req->sym_out = req1.sym_out; 3786 req->defobj_out = req1.defobj_out; 3787 return (res); 3788 } 3789 } 3790 } 3791 return (mres); 3792} 3793 3794/* Symbol match routine common to both hash functions */ 3795static bool 3796matched_symbol(SymLook *req, const Obj_Entry *obj, Sym_Match_Result *result, 3797 const unsigned long symnum) 3798{ 3799 Elf_Versym verndx; 3800 const Elf_Sym *symp; 3801 const char *strp; 3802 3803 symp = obj->symtab + symnum; 3804 strp = obj->strtab + symp->st_name; 3805 3806 switch (ELF_ST_TYPE(symp->st_info)) { 3807 case STT_FUNC: 3808 case STT_NOTYPE: 3809 case STT_OBJECT: 3810 case STT_COMMON: 3811 case STT_GNU_IFUNC: 3812 if (symp->st_value == 0) 3813 return (false); 3814 /* fallthrough */ 3815 case STT_TLS: 3816 if (symp->st_shndx != SHN_UNDEF) 3817 break; 3818#ifndef __mips__ 3819 else if (((req->flags & SYMLOOK_IN_PLT) == 0) && 3820 (ELF_ST_TYPE(symp->st_info) == STT_FUNC)) 3821 break; 3822 /* fallthrough */ 3823#endif 3824 default: 3825 return (false); 3826 } 3827 if (req->name[0] != strp[0] || strcmp(req->name, strp) != 0) 3828 return (false); 3829 3830 if (req->ventry == NULL) { 3831 if (obj->versyms != NULL) { 3832 verndx = VER_NDX(obj->versyms[symnum]); 3833 if (verndx > obj->vernum) { 3834 _rtld_error( 3835 "%s: symbol %s references wrong version %d", 3836 obj->path, obj->strtab + symnum, verndx); 3837 return (false); 3838 } 3839 /* 3840 * If we are not called from dlsym (i.e. this 3841 * is a normal relocation from unversioned 3842 * binary), accept the symbol immediately if 3843 * it happens to have first version after this 3844 * shared object became versioned. Otherwise, 3845 * if symbol is versioned and not hidden, 3846 * remember it. If it is the only symbol with 3847 * this name exported by the shared object, it 3848 * will be returned as a match by the calling 3849 * function. If symbol is global (verndx < 2) 3850 * accept it unconditionally. 3851 */ 3852 if ((req->flags & SYMLOOK_DLSYM) == 0 && 3853 verndx == VER_NDX_GIVEN) { 3854 result->sym_out = symp; 3855 return (true); 3856 } 3857 else if (verndx >= VER_NDX_GIVEN) { 3858 if ((obj->versyms[symnum] & VER_NDX_HIDDEN) 3859 == 0) { 3860 if (result->vsymp == NULL) 3861 result->vsymp = symp; 3862 result->vcount++; 3863 } 3864 return (false); 3865 } 3866 } 3867 result->sym_out = symp; 3868 return (true); 3869 } 3870 if (obj->versyms == NULL) { 3871 if (object_match_name(obj, req->ventry->name)) { 3872 _rtld_error("%s: object %s should provide version %s " 3873 "for symbol %s", obj_rtld.path, obj->path, 3874 req->ventry->name, obj->strtab + symnum); 3875 return (false); 3876 } 3877 } else { 3878 verndx = VER_NDX(obj->versyms[symnum]); 3879 if (verndx > obj->vernum) { 3880 _rtld_error("%s: symbol %s references wrong version %d", 3881 obj->path, obj->strtab + symnum, verndx); 3882 return (false); 3883 } 3884 if (obj->vertab[verndx].hash != req->ventry->hash || 3885 strcmp(obj->vertab[verndx].name, req->ventry->name)) { 3886 /* 3887 * Version does not match. Look if this is a 3888 * global symbol and if it is not hidden. If 3889 * global symbol (verndx < 2) is available, 3890 * use it. Do not return symbol if we are 3891 * called by dlvsym, because dlvsym looks for 3892 * a specific version and default one is not 3893 * what dlvsym wants. 3894 */ 3895 if ((req->flags & SYMLOOK_DLSYM) || 3896 (verndx >= VER_NDX_GIVEN) || 3897 (obj->versyms[symnum] & VER_NDX_HIDDEN)) 3898 return (false); 3899 } 3900 } 3901 result->sym_out = symp; 3902 return (true); 3903} 3904 3905/* 3906 * Search for symbol using SysV hash function. 3907 * obj->buckets is known not to be NULL at this point; the test for this was 3908 * performed with the obj->valid_hash_sysv assignment. 3909 */ 3910static int 3911symlook_obj1_sysv(SymLook *req, const Obj_Entry *obj) 3912{ 3913 unsigned long symnum; 3914 Sym_Match_Result matchres; 3915 3916 matchres.sym_out = NULL; 3917 matchres.vsymp = NULL; 3918 matchres.vcount = 0; 3919 3920 for (symnum = obj->buckets[req->hash % obj->nbuckets]; 3921 symnum != STN_UNDEF; symnum = obj->chains[symnum]) { 3922 if (symnum >= obj->nchains) 3923 return (ESRCH); /* Bad object */ 3924 3925 if (matched_symbol(req, obj, &matchres, symnum)) { 3926 req->sym_out = matchres.sym_out; 3927 req->defobj_out = obj; 3928 return (0); 3929 } 3930 } 3931 if (matchres.vcount == 1) { 3932 req->sym_out = matchres.vsymp; 3933 req->defobj_out = obj; 3934 return (0); 3935 } 3936 return (ESRCH); 3937} 3938 3939/* Search for symbol using GNU hash function */ 3940static int 3941symlook_obj1_gnu(SymLook *req, const Obj_Entry *obj) 3942{ 3943 Elf_Addr bloom_word; 3944 const Elf32_Word *hashval; 3945 Elf32_Word bucket; 3946 Sym_Match_Result matchres; 3947 unsigned int h1, h2; 3948 unsigned long symnum; 3949 3950 matchres.sym_out = NULL; 3951 matchres.vsymp = NULL; 3952 matchres.vcount = 0; 3953 3954 /* Pick right bitmask word from Bloom filter array */ 3955 bloom_word = obj->bloom_gnu[(req->hash_gnu / __ELF_WORD_SIZE) & 3956 obj->maskwords_bm_gnu]; 3957 3958 /* Calculate modulus word size of gnu hash and its derivative */ 3959 h1 = req->hash_gnu & (__ELF_WORD_SIZE - 1); 3960 h2 = ((req->hash_gnu >> obj->shift2_gnu) & (__ELF_WORD_SIZE - 1)); 3961 3962 /* Filter out the "definitely not in set" queries */ 3963 if (((bloom_word >> h1) & (bloom_word >> h2) & 1) == 0) 3964 return (ESRCH); 3965 3966 /* Locate hash chain and corresponding value element*/ 3967 bucket = obj->buckets_gnu[req->hash_gnu % obj->nbuckets_gnu]; 3968 if (bucket == 0) 3969 return (ESRCH); 3970 hashval = &obj->chain_zero_gnu[bucket]; 3971 do { 3972 if (((*hashval ^ req->hash_gnu) >> 1) == 0) { 3973 symnum = hashval - obj->chain_zero_gnu; 3974 if (matched_symbol(req, obj, &matchres, symnum)) { 3975 req->sym_out = matchres.sym_out; 3976 req->defobj_out = obj; 3977 return (0); 3978 } 3979 } 3980 } while ((*hashval++ & 1) == 0); 3981 if (matchres.vcount == 1) { 3982 req->sym_out = matchres.vsymp; 3983 req->defobj_out = obj; 3984 return (0); 3985 } 3986 return (ESRCH); 3987} 3988 3989static void 3990trace_loaded_objects(Obj_Entry *obj) 3991{ 3992 char *fmt1, *fmt2, *fmt, *main_local, *list_containers; 3993 int c; 3994 3995 if ((main_local = getenv(LD_ "TRACE_LOADED_OBJECTS_PROGNAME")) == NULL) 3996 main_local = ""; 3997 3998 if ((fmt1 = getenv(LD_ "TRACE_LOADED_OBJECTS_FMT1")) == NULL) 3999 fmt1 = "\t%o => %p (%x)\n"; 4000 4001 if ((fmt2 = getenv(LD_ "TRACE_LOADED_OBJECTS_FMT2")) == NULL) 4002 fmt2 = "\t%o (%x)\n"; 4003 4004 list_containers = getenv(LD_ "TRACE_LOADED_OBJECTS_ALL"); 4005 4006 for (; obj; obj = obj->next) { 4007 Needed_Entry *needed; 4008 char *name, *path; 4009 bool is_lib; 4010 4011 if (list_containers && obj->needed != NULL) 4012 rtld_printf("%s:\n", obj->path); 4013 for (needed = obj->needed; needed; needed = needed->next) { 4014 if (needed->obj != NULL) { 4015 if (needed->obj->traced && !list_containers) 4016 continue; 4017 needed->obj->traced = true; 4018 path = needed->obj->path; 4019 } else 4020 path = "not found"; 4021 4022 name = (char *)obj->strtab + needed->name; 4023 is_lib = strncmp(name, "lib", 3) == 0; /* XXX - bogus */ 4024 4025 fmt = is_lib ? fmt1 : fmt2; 4026 while ((c = *fmt++) != '\0') { 4027 switch (c) { 4028 default: 4029 rtld_putchar(c); 4030 continue; 4031 case '\\': 4032 switch (c = *fmt) { 4033 case '\0': 4034 continue; 4035 case 'n': 4036 rtld_putchar('\n'); 4037 break; 4038 case 't': 4039 rtld_putchar('\t'); 4040 break; 4041 } 4042 break; 4043 case '%': 4044 switch (c = *fmt) { 4045 case '\0': 4046 continue; 4047 case '%': 4048 default: 4049 rtld_putchar(c); 4050 break; 4051 case 'A': 4052 rtld_putstr(main_local); 4053 break; 4054 case 'a': 4055 rtld_putstr(obj_main->path); 4056 break; 4057 case 'o': 4058 rtld_putstr(name); 4059 break; 4060#if 0 4061 case 'm': 4062 rtld_printf("%d", sodp->sod_major); 4063 break; 4064 case 'n': 4065 rtld_printf("%d", sodp->sod_minor); 4066 break; 4067#endif 4068 case 'p': 4069 rtld_putstr(path); 4070 break; 4071 case 'x': 4072 rtld_printf("%p", needed->obj ? needed->obj->mapbase : 4073 0); 4074 break; 4075 } 4076 break; 4077 } 4078 ++fmt; 4079 } 4080 } 4081 } 4082} 4083 4084/* 4085 * Unload a dlopened object and its dependencies from memory and from 4086 * our data structures. It is assumed that the DAG rooted in the 4087 * object has already been unreferenced, and that the object has a 4088 * reference count of 0. 4089 */ 4090static void 4091unload_object(Obj_Entry *root) 4092{ 4093 Obj_Entry *obj; 4094 Obj_Entry **linkp; 4095 4096 assert(root->refcount == 0); 4097 4098 /* 4099 * Pass over the DAG removing unreferenced objects from 4100 * appropriate lists. 4101 */ 4102 unlink_object(root); 4103 4104 /* Unmap all objects that are no longer referenced. */ 4105 linkp = &obj_list->next; 4106 while ((obj = *linkp) != NULL) { 4107 if (obj->refcount == 0) { 4108 LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 4109 obj->path); 4110 dbg("unloading \"%s\"", obj->path); 4111 unload_filtees(root); 4112 munmap(obj->mapbase, obj->mapsize); 4113 linkmap_delete(obj); 4114 *linkp = obj->next; 4115 obj_count--; 4116 obj_free(obj); 4117 } else 4118 linkp = &obj->next; 4119 } 4120 obj_tail = linkp; 4121} 4122 4123static void 4124unlink_object(Obj_Entry *root) 4125{ 4126 Objlist_Entry *elm; 4127 4128 if (root->refcount == 0) { 4129 /* Remove the object from the RTLD_GLOBAL list. */ 4130 objlist_remove(&list_global, root); 4131 4132 /* Remove the object from all objects' DAG lists. */ 4133 STAILQ_FOREACH(elm, &root->dagmembers, link) { 4134 objlist_remove(&elm->obj->dldags, root); 4135 if (elm->obj != root) 4136 unlink_object(elm->obj); 4137 } 4138 } 4139} 4140 4141static void 4142ref_dag(Obj_Entry *root) 4143{ 4144 Objlist_Entry *elm; 4145 4146 assert(root->dag_inited); 4147 STAILQ_FOREACH(elm, &root->dagmembers, link) 4148 elm->obj->refcount++; 4149} 4150 4151static void 4152unref_dag(Obj_Entry *root) 4153{ 4154 Objlist_Entry *elm; 4155 4156 assert(root->dag_inited); 4157 STAILQ_FOREACH(elm, &root->dagmembers, link) 4158 elm->obj->refcount--; 4159} 4160 4161/* 4162 * Common code for MD __tls_get_addr(). 4163 */ 4164static void *tls_get_addr_slow(Elf_Addr **, int, size_t) __noinline; 4165static void * 4166tls_get_addr_slow(Elf_Addr **dtvp, int index, size_t offset) 4167{ 4168 Elf_Addr *newdtv, *dtv; 4169 RtldLockState lockstate; 4170 int to_copy; 4171 4172 dtv = *dtvp; 4173 /* Check dtv generation in case new modules have arrived */ 4174 if (dtv[0] != tls_dtv_generation) { 4175 wlock_acquire(rtld_bind_lock, &lockstate); 4176 newdtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4177 to_copy = dtv[1]; 4178 if (to_copy > tls_max_index) 4179 to_copy = tls_max_index; 4180 memcpy(&newdtv[2], &dtv[2], to_copy * sizeof(Elf_Addr)); 4181 newdtv[0] = tls_dtv_generation; 4182 newdtv[1] = tls_max_index; 4183 free(dtv); 4184 lock_release(rtld_bind_lock, &lockstate); 4185 dtv = *dtvp = newdtv; 4186 } 4187 4188 /* Dynamically allocate module TLS if necessary */ 4189 if (dtv[index + 1] == 0) { 4190 /* Signal safe, wlock will block out signals. */ 4191 wlock_acquire(rtld_bind_lock, &lockstate); 4192 if (!dtv[index + 1]) 4193 dtv[index + 1] = (Elf_Addr)allocate_module_tls(index); 4194 lock_release(rtld_bind_lock, &lockstate); 4195 } 4196 return ((void *)(dtv[index + 1] + offset)); 4197} 4198 4199void * 4200tls_get_addr_common(Elf_Addr **dtvp, int index, size_t offset) 4201{ 4202 Elf_Addr *dtv; 4203 4204 dtv = *dtvp; 4205 /* Check dtv generation in case new modules have arrived */ 4206 if (__predict_true(dtv[0] == tls_dtv_generation && 4207 dtv[index + 1] != 0)) 4208 return ((void *)(dtv[index + 1] + offset)); 4209 return (tls_get_addr_slow(dtvp, index, offset)); 4210} 4211 4212#if defined(__arm__) || defined(__ia64__) || defined(__mips__) || defined(__powerpc__) 4213 4214/* 4215 * Allocate Static TLS using the Variant I method. 4216 */ 4217void * 4218allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign) 4219{ 4220 Obj_Entry *obj; 4221 char *tcb; 4222 Elf_Addr **tls; 4223 Elf_Addr *dtv; 4224 Elf_Addr addr; 4225 int i; 4226 4227 if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE) 4228 return (oldtcb); 4229 4230 assert(tcbsize >= TLS_TCB_SIZE); 4231 tcb = xcalloc(1, tls_static_space - TLS_TCB_SIZE + tcbsize); 4232 tls = (Elf_Addr **)(tcb + tcbsize - TLS_TCB_SIZE); 4233 4234 if (oldtcb != NULL) { 4235 memcpy(tls, oldtcb, tls_static_space); 4236 free(oldtcb); 4237 4238 /* Adjust the DTV. */ 4239 dtv = tls[0]; 4240 for (i = 0; i < dtv[1]; i++) { 4241 if (dtv[i+2] >= (Elf_Addr)oldtcb && 4242 dtv[i+2] < (Elf_Addr)oldtcb + tls_static_space) { 4243 dtv[i+2] = dtv[i+2] - (Elf_Addr)oldtcb + (Elf_Addr)tls; 4244 } 4245 } 4246 } else { 4247 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4248 tls[0] = dtv; 4249 dtv[0] = tls_dtv_generation; 4250 dtv[1] = tls_max_index; 4251 4252 for (obj = objs; obj; obj = obj->next) { 4253 if (obj->tlsoffset > 0) { 4254 addr = (Elf_Addr)tls + obj->tlsoffset; 4255 if (obj->tlsinitsize > 0) 4256 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize); 4257 if (obj->tlssize > obj->tlsinitsize) 4258 memset((void*) (addr + obj->tlsinitsize), 0, 4259 obj->tlssize - obj->tlsinitsize); 4260 dtv[obj->tlsindex + 1] = addr; 4261 } 4262 } 4263 } 4264 4265 return (tcb); 4266} 4267 4268void 4269free_tls(void *tcb, size_t tcbsize, size_t tcbalign) 4270{ 4271 Elf_Addr *dtv; 4272 Elf_Addr tlsstart, tlsend; 4273 int dtvsize, i; 4274 4275 assert(tcbsize >= TLS_TCB_SIZE); 4276 4277 tlsstart = (Elf_Addr)tcb + tcbsize - TLS_TCB_SIZE; 4278 tlsend = tlsstart + tls_static_space; 4279 4280 dtv = *(Elf_Addr **)tlsstart; 4281 dtvsize = dtv[1]; 4282 for (i = 0; i < dtvsize; i++) { 4283 if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] >= tlsend)) { 4284 free((void*)dtv[i+2]); 4285 } 4286 } 4287 free(dtv); 4288 free(tcb); 4289} 4290 4291#endif 4292 4293#if defined(__i386__) || defined(__amd64__) || defined(__sparc64__) 4294 4295/* 4296 * Allocate Static TLS using the Variant II method. 4297 */ 4298void * 4299allocate_tls(Obj_Entry *objs, void *oldtls, size_t tcbsize, size_t tcbalign) 4300{ 4301 Obj_Entry *obj; 4302 size_t size, ralign; 4303 char *tls; 4304 Elf_Addr *dtv, *olddtv; 4305 Elf_Addr segbase, oldsegbase, addr; 4306 int i; 4307 4308 ralign = tcbalign; 4309 if (tls_static_max_align > ralign) 4310 ralign = tls_static_max_align; 4311 size = round(tls_static_space, ralign) + round(tcbsize, ralign); 4312 4313 assert(tcbsize >= 2*sizeof(Elf_Addr)); 4314 tls = malloc_aligned(size, ralign); 4315 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4316 4317 segbase = (Elf_Addr)(tls + round(tls_static_space, ralign)); 4318 ((Elf_Addr*)segbase)[0] = segbase; 4319 ((Elf_Addr*)segbase)[1] = (Elf_Addr) dtv; 4320 4321 dtv[0] = tls_dtv_generation; 4322 dtv[1] = tls_max_index; 4323 4324 if (oldtls) { 4325 /* 4326 * Copy the static TLS block over whole. 4327 */ 4328 oldsegbase = (Elf_Addr) oldtls; 4329 memcpy((void *)(segbase - tls_static_space), 4330 (const void *)(oldsegbase - tls_static_space), 4331 tls_static_space); 4332 4333 /* 4334 * If any dynamic TLS blocks have been created tls_get_addr(), 4335 * move them over. 4336 */ 4337 olddtv = ((Elf_Addr**)oldsegbase)[1]; 4338 for (i = 0; i < olddtv[1]; i++) { 4339 if (olddtv[i+2] < oldsegbase - size || olddtv[i+2] > oldsegbase) { 4340 dtv[i+2] = olddtv[i+2]; 4341 olddtv[i+2] = 0; 4342 } 4343 } 4344 4345 /* 4346 * We assume that this block was the one we created with 4347 * allocate_initial_tls(). 4348 */ 4349 free_tls(oldtls, 2*sizeof(Elf_Addr), sizeof(Elf_Addr)); 4350 } else { 4351 for (obj = objs; obj; obj = obj->next) { 4352 if (obj->tlsoffset) { 4353 addr = segbase - obj->tlsoffset; 4354 memset((void*) (addr + obj->tlsinitsize), 4355 0, obj->tlssize - obj->tlsinitsize); 4356 if (obj->tlsinit) 4357 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize); 4358 dtv[obj->tlsindex + 1] = addr; 4359 } 4360 } 4361 } 4362 4363 return (void*) segbase; 4364} 4365 4366void 4367free_tls(void *tls, size_t tcbsize, size_t tcbalign) 4368{ 4369 Elf_Addr* dtv; 4370 size_t size, ralign; 4371 int dtvsize, i; 4372 Elf_Addr tlsstart, tlsend; 4373 4374 /* 4375 * Figure out the size of the initial TLS block so that we can 4376 * find stuff which ___tls_get_addr() allocated dynamically. 4377 */ 4378 ralign = tcbalign; 4379 if (tls_static_max_align > ralign) 4380 ralign = tls_static_max_align; 4381 size = round(tls_static_space, ralign); 4382 4383 dtv = ((Elf_Addr**)tls)[1]; 4384 dtvsize = dtv[1]; 4385 tlsend = (Elf_Addr) tls; 4386 tlsstart = tlsend - size; 4387 for (i = 0; i < dtvsize; i++) { 4388 if (dtv[i + 2] != 0 && (dtv[i + 2] < tlsstart || dtv[i + 2] > tlsend)) { 4389 free_aligned((void *)dtv[i + 2]); 4390 } 4391 } 4392 4393 free_aligned((void *)tlsstart); 4394 free((void*) dtv); 4395} 4396 4397#endif 4398 4399/* 4400 * Allocate TLS block for module with given index. 4401 */ 4402void * 4403allocate_module_tls(int index) 4404{ 4405 Obj_Entry* obj; 4406 char* p; 4407 4408 for (obj = obj_list; obj; obj = obj->next) { 4409 if (obj->tlsindex == index) 4410 break; 4411 } 4412 if (!obj) { 4413 _rtld_error("Can't find module with TLS index %d", index); 4414 die(); 4415 } 4416 4417 p = malloc_aligned(obj->tlssize, obj->tlsalign); 4418 memcpy(p, obj->tlsinit, obj->tlsinitsize); 4419 memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize); 4420 4421 return p; 4422} 4423 4424bool 4425allocate_tls_offset(Obj_Entry *obj) 4426{ 4427 size_t off; 4428 4429 if (obj->tls_done) 4430 return true; 4431 4432 if (obj->tlssize == 0) { 4433 obj->tls_done = true; 4434 return true; 4435 } 4436 4437 if (obj->tlsindex == 1) 4438 off = calculate_first_tls_offset(obj->tlssize, obj->tlsalign); 4439 else 4440 off = calculate_tls_offset(tls_last_offset, tls_last_size, 4441 obj->tlssize, obj->tlsalign); 4442 4443 /* 4444 * If we have already fixed the size of the static TLS block, we 4445 * must stay within that size. When allocating the static TLS, we 4446 * leave a small amount of space spare to be used for dynamically 4447 * loading modules which use static TLS. 4448 */ 4449 if (tls_static_space != 0) { 4450 if (calculate_tls_end(off, obj->tlssize) > tls_static_space) 4451 return false; 4452 } else if (obj->tlsalign > tls_static_max_align) { 4453 tls_static_max_align = obj->tlsalign; 4454 } 4455 4456 tls_last_offset = obj->tlsoffset = off; 4457 tls_last_size = obj->tlssize; 4458 obj->tls_done = true; 4459 4460 return true; 4461} 4462 4463void 4464free_tls_offset(Obj_Entry *obj) 4465{ 4466 4467 /* 4468 * If we were the last thing to allocate out of the static TLS 4469 * block, we give our space back to the 'allocator'. This is a 4470 * simplistic workaround to allow libGL.so.1 to be loaded and 4471 * unloaded multiple times. 4472 */ 4473 if (calculate_tls_end(obj->tlsoffset, obj->tlssize) 4474 == calculate_tls_end(tls_last_offset, tls_last_size)) { 4475 tls_last_offset -= obj->tlssize; 4476 tls_last_size = 0; 4477 } 4478} 4479 4480void * 4481_rtld_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign) 4482{ 4483 void *ret; 4484 RtldLockState lockstate; 4485 4486 wlock_acquire(rtld_bind_lock, &lockstate); 4487 ret = allocate_tls(obj_list, oldtls, tcbsize, tcbalign); 4488 lock_release(rtld_bind_lock, &lockstate); 4489 return (ret); 4490} 4491 4492void 4493_rtld_free_tls(void *tcb, size_t tcbsize, size_t tcbalign) 4494{ 4495 RtldLockState lockstate; 4496 4497 wlock_acquire(rtld_bind_lock, &lockstate); 4498 free_tls(tcb, tcbsize, tcbalign); 4499 lock_release(rtld_bind_lock, &lockstate); 4500} 4501 4502static void 4503object_add_name(Obj_Entry *obj, const char *name) 4504{ 4505 Name_Entry *entry; 4506 size_t len; 4507 4508 len = strlen(name); 4509 entry = malloc(sizeof(Name_Entry) + len); 4510 4511 if (entry != NULL) { 4512 strcpy(entry->name, name); 4513 STAILQ_INSERT_TAIL(&obj->names, entry, link); 4514 } 4515} 4516 4517static int 4518object_match_name(const Obj_Entry *obj, const char *name) 4519{ 4520 Name_Entry *entry; 4521 4522 STAILQ_FOREACH(entry, &obj->names, link) { 4523 if (strcmp(name, entry->name) == 0) 4524 return (1); 4525 } 4526 return (0); 4527} 4528 4529static Obj_Entry * 4530locate_dependency(const Obj_Entry *obj, const char *name) 4531{ 4532 const Objlist_Entry *entry; 4533 const Needed_Entry *needed; 4534 4535 STAILQ_FOREACH(entry, &list_main, link) { 4536 if (object_match_name(entry->obj, name)) 4537 return entry->obj; 4538 } 4539 4540 for (needed = obj->needed; needed != NULL; needed = needed->next) { 4541 if (strcmp(obj->strtab + needed->name, name) == 0 || 4542 (needed->obj != NULL && object_match_name(needed->obj, name))) { 4543 /* 4544 * If there is DT_NEEDED for the name we are looking for, 4545 * we are all set. Note that object might not be found if 4546 * dependency was not loaded yet, so the function can 4547 * return NULL here. This is expected and handled 4548 * properly by the caller. 4549 */ 4550 return (needed->obj); 4551 } 4552 } 4553 _rtld_error("%s: Unexpected inconsistency: dependency %s not found", 4554 obj->path, name); 4555 die(); 4556} 4557 4558static int 4559check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj, 4560 const Elf_Vernaux *vna) 4561{ 4562 const Elf_Verdef *vd; 4563 const char *vername; 4564 4565 vername = refobj->strtab + vna->vna_name; 4566 vd = depobj->verdef; 4567 if (vd == NULL) { 4568 _rtld_error("%s: version %s required by %s not defined", 4569 depobj->path, vername, refobj->path); 4570 return (-1); 4571 } 4572 for (;;) { 4573 if (vd->vd_version != VER_DEF_CURRENT) { 4574 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 4575 depobj->path, vd->vd_version); 4576 return (-1); 4577 } 4578 if (vna->vna_hash == vd->vd_hash) { 4579 const Elf_Verdaux *aux = (const Elf_Verdaux *) 4580 ((char *)vd + vd->vd_aux); 4581 if (strcmp(vername, depobj->strtab + aux->vda_name) == 0) 4582 return (0); 4583 } 4584 if (vd->vd_next == 0) 4585 break; 4586 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next); 4587 } 4588 if (vna->vna_flags & VER_FLG_WEAK) 4589 return (0); 4590 _rtld_error("%s: version %s required by %s not found", 4591 depobj->path, vername, refobj->path); 4592 return (-1); 4593} 4594 4595static int 4596rtld_verify_object_versions(Obj_Entry *obj) 4597{ 4598 const Elf_Verneed *vn; 4599 const Elf_Verdef *vd; 4600 const Elf_Verdaux *vda; 4601 const Elf_Vernaux *vna; 4602 const Obj_Entry *depobj; 4603 int maxvernum, vernum; 4604 4605 if (obj->ver_checked) 4606 return (0); 4607 obj->ver_checked = true; 4608 4609 maxvernum = 0; 4610 /* 4611 * Walk over defined and required version records and figure out 4612 * max index used by any of them. Do very basic sanity checking 4613 * while there. 4614 */ 4615 vn = obj->verneed; 4616 while (vn != NULL) { 4617 if (vn->vn_version != VER_NEED_CURRENT) { 4618 _rtld_error("%s: Unsupported version %d of Elf_Verneed entry", 4619 obj->path, vn->vn_version); 4620 return (-1); 4621 } 4622 vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux); 4623 for (;;) { 4624 vernum = VER_NEED_IDX(vna->vna_other); 4625 if (vernum > maxvernum) 4626 maxvernum = vernum; 4627 if (vna->vna_next == 0) 4628 break; 4629 vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next); 4630 } 4631 if (vn->vn_next == 0) 4632 break; 4633 vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next); 4634 } 4635 4636 vd = obj->verdef; 4637 while (vd != NULL) { 4638 if (vd->vd_version != VER_DEF_CURRENT) { 4639 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 4640 obj->path, vd->vd_version); 4641 return (-1); 4642 } 4643 vernum = VER_DEF_IDX(vd->vd_ndx); 4644 if (vernum > maxvernum) 4645 maxvernum = vernum; 4646 if (vd->vd_next == 0) 4647 break; 4648 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next); 4649 } 4650 4651 if (maxvernum == 0) 4652 return (0); 4653 4654 /* 4655 * Store version information in array indexable by version index. 4656 * Verify that object version requirements are satisfied along the 4657 * way. 4658 */ 4659 obj->vernum = maxvernum + 1; 4660 obj->vertab = xcalloc(obj->vernum, sizeof(Ver_Entry)); 4661 4662 vd = obj->verdef; 4663 while (vd != NULL) { 4664 if ((vd->vd_flags & VER_FLG_BASE) == 0) { 4665 vernum = VER_DEF_IDX(vd->vd_ndx); 4666 assert(vernum <= maxvernum); 4667 vda = (const Elf_Verdaux *)((char *)vd + vd->vd_aux); 4668 obj->vertab[vernum].hash = vd->vd_hash; 4669 obj->vertab[vernum].name = obj->strtab + vda->vda_name; 4670 obj->vertab[vernum].file = NULL; 4671 obj->vertab[vernum].flags = 0; 4672 } 4673 if (vd->vd_next == 0) 4674 break; 4675 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next); 4676 } 4677 4678 vn = obj->verneed; 4679 while (vn != NULL) { 4680 depobj = locate_dependency(obj, obj->strtab + vn->vn_file); 4681 if (depobj == NULL) 4682 return (-1); 4683 vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux); 4684 for (;;) { 4685 if (check_object_provided_version(obj, depobj, vna)) 4686 return (-1); 4687 vernum = VER_NEED_IDX(vna->vna_other); 4688 assert(vernum <= maxvernum); 4689 obj->vertab[vernum].hash = vna->vna_hash; 4690 obj->vertab[vernum].name = obj->strtab + vna->vna_name; 4691 obj->vertab[vernum].file = obj->strtab + vn->vn_file; 4692 obj->vertab[vernum].flags = (vna->vna_other & VER_NEED_HIDDEN) ? 4693 VER_INFO_HIDDEN : 0; 4694 if (vna->vna_next == 0) 4695 break; 4696 vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next); 4697 } 4698 if (vn->vn_next == 0) 4699 break; 4700 vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next); 4701 } 4702 return 0; 4703} 4704 4705static int 4706rtld_verify_versions(const Objlist *objlist) 4707{ 4708 Objlist_Entry *entry; 4709 int rc; 4710 4711 rc = 0; 4712 STAILQ_FOREACH(entry, objlist, link) { 4713 /* 4714 * Skip dummy objects or objects that have their version requirements 4715 * already checked. 4716 */ 4717 if (entry->obj->strtab == NULL || entry->obj->vertab != NULL) 4718 continue; 4719 if (rtld_verify_object_versions(entry->obj) == -1) { 4720 rc = -1; 4721 if (ld_tracing == NULL) 4722 break; 4723 } 4724 } 4725 if (rc == 0 || ld_tracing != NULL) 4726 rc = rtld_verify_object_versions(&obj_rtld); 4727 return rc; 4728} 4729 4730const Ver_Entry * 4731fetch_ventry(const Obj_Entry *obj, unsigned long symnum) 4732{ 4733 Elf_Versym vernum; 4734 4735 if (obj->vertab) { 4736 vernum = VER_NDX(obj->versyms[symnum]); 4737 if (vernum >= obj->vernum) { 4738 _rtld_error("%s: symbol %s has wrong verneed value %d", 4739 obj->path, obj->strtab + symnum, vernum); 4740 } else if (obj->vertab[vernum].hash != 0) { 4741 return &obj->vertab[vernum]; 4742 } 4743 } 4744 return NULL; 4745} 4746 4747int 4748_rtld_get_stack_prot(void) 4749{ 4750 4751 return (stack_prot); 4752} 4753 4754int 4755_rtld_is_dlopened(void *arg) 4756{ 4757 Obj_Entry *obj; 4758 RtldLockState lockstate; 4759 int res; 4760 4761 rlock_acquire(rtld_bind_lock, &lockstate); 4762 obj = dlcheck(arg); 4763 if (obj == NULL) 4764 obj = obj_from_addr(arg); 4765 if (obj == NULL) { 4766 _rtld_error("No shared object contains address"); 4767 lock_release(rtld_bind_lock, &lockstate); 4768 return (-1); 4769 } 4770 res = obj->dlopened ? 1 : 0; 4771 lock_release(rtld_bind_lock, &lockstate); 4772 return (res); 4773} 4774 4775static void 4776map_stacks_exec(RtldLockState *lockstate) 4777{ 4778 void (*thr_map_stacks_exec)(void); 4779 4780 if ((max_stack_flags & PF_X) == 0 || (stack_prot & PROT_EXEC) != 0) 4781 return; 4782 thr_map_stacks_exec = (void (*)(void))(uintptr_t) 4783 get_program_var_addr("__pthread_map_stacks_exec", lockstate); 4784 if (thr_map_stacks_exec != NULL) { 4785 stack_prot |= PROT_EXEC; 4786 thr_map_stacks_exec(); 4787 } 4788} 4789 4790void 4791symlook_init(SymLook *dst, const char *name) 4792{ 4793 4794 bzero(dst, sizeof(*dst)); 4795 dst->name = name; 4796 dst->hash = elf_hash(name); 4797 dst->hash_gnu = gnu_hash(name); 4798} 4799 4800static void 4801symlook_init_from_req(SymLook *dst, const SymLook *src) 4802{ 4803 4804 dst->name = src->name; 4805 dst->hash = src->hash; 4806 dst->hash_gnu = src->hash_gnu; 4807 dst->ventry = src->ventry; 4808 dst->flags = src->flags; 4809 dst->defobj_out = NULL; 4810 dst->sym_out = NULL; 4811 dst->lockstate = src->lockstate; 4812} 4813 4814/* 4815 * Overrides for libc_pic-provided functions. 4816 */ 4817 4818int 4819__getosreldate(void) 4820{ 4821 size_t len; 4822 int oid[2]; 4823 int error, osrel; 4824 4825 if (osreldate != 0) 4826 return (osreldate); 4827 4828 oid[0] = CTL_KERN; 4829 oid[1] = KERN_OSRELDATE; 4830 osrel = 0; 4831 len = sizeof(osrel); 4832 error = sysctl(oid, 2, &osrel, &len, NULL, 0); 4833 if (error == 0 && osrel > 0 && len == sizeof(osrel)) 4834 osreldate = osrel; 4835 return (osreldate); 4836} 4837 4838void 4839exit(int status) 4840{ 4841 4842 _exit(status); 4843} 4844 4845void (*__cleanup)(void); 4846int __isthreaded = 0; 4847int _thread_autoinit_dummy_decl = 1; 4848 4849/* 4850 * No unresolved symbols for rtld. 4851 */ 4852void 4853__pthread_cxa_finalize(struct dl_phdr_info *a) 4854{ 4855} 4856 4857void 4858__stack_chk_fail(void) 4859{ 4860 4861 _rtld_error("stack overflow detected; terminated"); 4862 die(); 4863} 4864__weak_reference(__stack_chk_fail, __stack_chk_fail_local); 4865 4866void 4867__chk_fail(void) 4868{ 4869 4870 _rtld_error("buffer overflow detected; terminated"); 4871 die(); 4872} 4873 4874const char * 4875rtld_strerror(int errnum) 4876{ 4877 4878 if (errnum < 0 || errnum >= sys_nerr) 4879 return ("Unknown error"); 4880 return (sys_errlist[errnum]); 4881} 4882