rtld.c revision 281452
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 281452 2015-04-12 06:43:13Z 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_pagesizes(Elf_Auxinfo **aux_info); 101static void init_rtld(caddr_t, Elf_Auxinfo **); 102static void initlist_add_neededs(Needed_Entry *, Objlist *); 103static void initlist_add_objects(Obj_Entry *, Obj_Entry **, Objlist *); 104static void linkmap_add(Obj_Entry *); 105static void linkmap_delete(Obj_Entry *); 106static void load_filtees(Obj_Entry *, int flags, RtldLockState *); 107static void unload_filtees(Obj_Entry *); 108static int load_needed_objects(Obj_Entry *, int); 109static int load_preload_objects(void); 110static Obj_Entry *load_object(const char *, int fd, const Obj_Entry *, int); 111static void map_stacks_exec(RtldLockState *); 112static Obj_Entry *obj_from_addr(const void *); 113static void objlist_call_fini(Objlist *, Obj_Entry *, RtldLockState *); 114static void objlist_call_init(Objlist *, RtldLockState *); 115static void objlist_clear(Objlist *); 116static Objlist_Entry *objlist_find(Objlist *, const Obj_Entry *); 117static void objlist_init(Objlist *); 118static void objlist_push_head(Objlist *, Obj_Entry *); 119static void objlist_push_tail(Objlist *, Obj_Entry *); 120static void objlist_put_after(Objlist *, Obj_Entry *, Obj_Entry *); 121static void objlist_remove(Objlist *, Obj_Entry *); 122static void *path_enumerate(const char *, path_enum_proc, void *); 123static int relocate_object_dag(Obj_Entry *root, bool bind_now, 124 Obj_Entry *rtldobj, int flags, RtldLockState *lockstate); 125static int relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, 126 int flags, RtldLockState *lockstate); 127static int relocate_objects(Obj_Entry *, bool, Obj_Entry *, int, 128 RtldLockState *); 129static int resolve_objects_ifunc(Obj_Entry *first, bool bind_now, 130 int flags, RtldLockState *lockstate); 131static int rtld_dirname(const char *, char *); 132static int rtld_dirname_abs(const char *, char *); 133static void *rtld_dlopen(const char *name, int fd, int mode); 134static void rtld_exit(void); 135static char *search_library_path(const char *, const char *); 136static const void **get_program_var_addr(const char *, RtldLockState *); 137static void set_program_var(const char *, const void *); 138static int symlook_default(SymLook *, const Obj_Entry *refobj); 139static int symlook_global(SymLook *, DoneList *); 140static void symlook_init_from_req(SymLook *, const SymLook *); 141static int symlook_list(SymLook *, const Objlist *, DoneList *); 142static int symlook_needed(SymLook *, const Needed_Entry *, DoneList *); 143static int symlook_obj1_sysv(SymLook *, const Obj_Entry *); 144static int symlook_obj1_gnu(SymLook *, const Obj_Entry *); 145static void trace_loaded_objects(Obj_Entry *); 146static void unlink_object(Obj_Entry *); 147static void unload_object(Obj_Entry *); 148static void unref_dag(Obj_Entry *); 149static void ref_dag(Obj_Entry *); 150static char *origin_subst_one(char *, const char *, const char *, bool); 151static char *origin_subst(char *, const char *); 152static void preinit_main(void); 153static int rtld_verify_versions(const Objlist *); 154static int rtld_verify_object_versions(Obj_Entry *); 155static void object_add_name(Obj_Entry *, const char *); 156static int object_match_name(const Obj_Entry *, const char *); 157static void ld_utrace_log(int, void *, void *, size_t, int, const char *); 158static void rtld_fill_dl_phdr_info(const Obj_Entry *obj, 159 struct dl_phdr_info *phdr_info); 160static uint32_t gnu_hash(const char *); 161static bool matched_symbol(SymLook *, const Obj_Entry *, Sym_Match_Result *, 162 const unsigned long); 163 164void r_debug_state(struct r_debug *, struct link_map *) __noinline; 165void _r_debug_postinit(struct link_map *) __noinline; 166 167/* 168 * Data declarations. 169 */ 170static char *error_message; /* Message for dlerror(), or NULL */ 171struct r_debug r_debug; /* for GDB; */ 172static bool libmap_disable; /* Disable libmap */ 173static bool ld_loadfltr; /* Immediate filters processing */ 174static char *libmap_override; /* Maps to use in addition to libmap.conf */ 175static bool trust; /* False for setuid and setgid programs */ 176static bool dangerous_ld_env; /* True if environment variables have been 177 used to affect the libraries loaded */ 178static char *ld_bind_now; /* Environment variable for immediate binding */ 179static char *ld_debug; /* Environment variable for debugging */ 180static char *ld_library_path; /* Environment variable for search path */ 181static char *ld_preload; /* Environment variable for libraries to 182 load first */ 183static char *ld_elf_hints_path; /* Environment variable for alternative hints path */ 184static char *ld_tracing; /* Called from ldd to print libs */ 185static char *ld_utrace; /* Use utrace() to log events. */ 186static Obj_Entry *obj_list; /* Head of linked list of shared objects */ 187static Obj_Entry **obj_tail; /* Link field of last object in list */ 188static Obj_Entry *obj_main; /* The main program shared object */ 189static Obj_Entry obj_rtld; /* The dynamic linker shared object */ 190static unsigned int obj_count; /* Number of objects in obj_list */ 191static unsigned int obj_loads; /* Number of objects in obj_list */ 192 193static Objlist list_global = /* Objects dlopened with RTLD_GLOBAL */ 194 STAILQ_HEAD_INITIALIZER(list_global); 195static Objlist list_main = /* Objects loaded at program startup */ 196 STAILQ_HEAD_INITIALIZER(list_main); 197static Objlist list_fini = /* Objects needing fini() calls */ 198 STAILQ_HEAD_INITIALIZER(list_fini); 199 200Elf_Sym sym_zero; /* For resolving undefined weak refs. */ 201 202#define GDB_STATE(s,m) r_debug.r_state = s; r_debug_state(&r_debug,m); 203 204extern Elf_Dyn _DYNAMIC; 205#pragma weak _DYNAMIC 206#ifndef RTLD_IS_DYNAMIC 207#define RTLD_IS_DYNAMIC() (&_DYNAMIC != NULL) 208#endif 209 210int npagesizes, osreldate; 211size_t *pagesizes; 212 213long __stack_chk_guard[8] = {0, 0, 0, 0, 0, 0, 0, 0}; 214 215static int stack_prot = PROT_READ | PROT_WRITE | RTLD_DEFAULT_STACK_EXEC; 216static int max_stack_flags; 217 218/* 219 * Global declarations normally provided by crt1. The dynamic linker is 220 * not built with crt1, so we have to provide them ourselves. 221 */ 222char *__progname; 223char **environ; 224 225/* 226 * Used to pass argc, argv to init functions. 227 */ 228int main_argc; 229char **main_argv; 230 231/* 232 * Globals to control TLS allocation. 233 */ 234size_t tls_last_offset; /* Static TLS offset of last module */ 235size_t tls_last_size; /* Static TLS size of last module */ 236size_t tls_static_space; /* Static TLS space allocated */ 237size_t tls_static_max_align; 238int tls_dtv_generation = 1; /* Used to detect when dtv size changes */ 239int tls_max_index = 1; /* Largest module index allocated */ 240 241bool ld_library_path_rpath = false; 242 243/* 244 * Fill in a DoneList with an allocation large enough to hold all of 245 * the currently-loaded objects. Keep this as a macro since it calls 246 * alloca and we want that to occur within the scope of the caller. 247 */ 248#define donelist_init(dlp) \ 249 ((dlp)->objs = alloca(obj_count * sizeof (dlp)->objs[0]), \ 250 assert((dlp)->objs != NULL), \ 251 (dlp)->num_alloc = obj_count, \ 252 (dlp)->num_used = 0) 253 254#define UTRACE_DLOPEN_START 1 255#define UTRACE_DLOPEN_STOP 2 256#define UTRACE_DLCLOSE_START 3 257#define UTRACE_DLCLOSE_STOP 4 258#define UTRACE_LOAD_OBJECT 5 259#define UTRACE_UNLOAD_OBJECT 6 260#define UTRACE_ADD_RUNDEP 7 261#define UTRACE_PRELOAD_FINISHED 8 262#define UTRACE_INIT_CALL 9 263#define UTRACE_FINI_CALL 10 264 265struct utrace_rtld { 266 char sig[4]; /* 'RTLD' */ 267 int event; 268 void *handle; 269 void *mapbase; /* Used for 'parent' and 'init/fini' */ 270 size_t mapsize; 271 int refcnt; /* Used for 'mode' */ 272 char name[MAXPATHLEN]; 273}; 274 275#define LD_UTRACE(e, h, mb, ms, r, n) do { \ 276 if (ld_utrace != NULL) \ 277 ld_utrace_log(e, h, mb, ms, r, n); \ 278} while (0) 279 280static void 281ld_utrace_log(int event, void *handle, void *mapbase, size_t mapsize, 282 int refcnt, const char *name) 283{ 284 struct utrace_rtld ut; 285 286 ut.sig[0] = 'R'; 287 ut.sig[1] = 'T'; 288 ut.sig[2] = 'L'; 289 ut.sig[3] = 'D'; 290 ut.event = event; 291 ut.handle = handle; 292 ut.mapbase = mapbase; 293 ut.mapsize = mapsize; 294 ut.refcnt = refcnt; 295 bzero(ut.name, sizeof(ut.name)); 296 if (name) 297 strlcpy(ut.name, name, sizeof(ut.name)); 298 utrace(&ut, sizeof(ut)); 299} 300 301/* 302 * Main entry point for dynamic linking. The first argument is the 303 * stack pointer. The stack is expected to be laid out as described 304 * in the SVR4 ABI specification, Intel 386 Processor Supplement. 305 * Specifically, the stack pointer points to a word containing 306 * ARGC. Following that in the stack is a null-terminated sequence 307 * of pointers to argument strings. Then comes a null-terminated 308 * sequence of pointers to environment strings. Finally, there is a 309 * sequence of "auxiliary vector" entries. 310 * 311 * The second argument points to a place to store the dynamic linker's 312 * exit procedure pointer and the third to a place to store the main 313 * program's object. 314 * 315 * The return value is the main program's entry point. 316 */ 317func_ptr_type 318_rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp) 319{ 320 Elf_Auxinfo *aux_info[AT_COUNT]; 321 int i; 322 int argc; 323 char **argv; 324 char **env; 325 Elf_Auxinfo *aux; 326 Elf_Auxinfo *auxp; 327 const char *argv0; 328 Objlist_Entry *entry; 329 Obj_Entry *obj; 330 Obj_Entry **preload_tail; 331 Obj_Entry *last_interposer; 332 Objlist initlist; 333 RtldLockState lockstate; 334 char *library_path_rpath; 335 int mib[2]; 336 size_t len; 337 338 /* 339 * On entry, the dynamic linker itself has not been relocated yet. 340 * Be very careful not to reference any global data until after 341 * init_rtld has returned. It is OK to reference file-scope statics 342 * and string constants, and to call static and global functions. 343 */ 344 345 /* Find the auxiliary vector on the stack. */ 346 argc = *sp++; 347 argv = (char **) sp; 348 sp += argc + 1; /* Skip over arguments and NULL terminator */ 349 env = (char **) sp; 350 while (*sp++ != 0) /* Skip over environment, and NULL terminator */ 351 ; 352 aux = (Elf_Auxinfo *) sp; 353 354 /* Digest the auxiliary vector. */ 355 for (i = 0; i < AT_COUNT; i++) 356 aux_info[i] = NULL; 357 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) { 358 if (auxp->a_type < AT_COUNT) 359 aux_info[auxp->a_type] = auxp; 360 } 361 362 /* Initialize and relocate ourselves. */ 363 assert(aux_info[AT_BASE] != NULL); 364 init_rtld((caddr_t) aux_info[AT_BASE]->a_un.a_ptr, aux_info); 365 366 __progname = obj_rtld.path; 367 argv0 = argv[0] != NULL ? argv[0] : "(null)"; 368 environ = env; 369 main_argc = argc; 370 main_argv = argv; 371 372 if (aux_info[AT_CANARY] != NULL && 373 aux_info[AT_CANARY]->a_un.a_ptr != NULL) { 374 i = aux_info[AT_CANARYLEN]->a_un.a_val; 375 if (i > sizeof(__stack_chk_guard)) 376 i = sizeof(__stack_chk_guard); 377 memcpy(__stack_chk_guard, aux_info[AT_CANARY]->a_un.a_ptr, i); 378 } else { 379 mib[0] = CTL_KERN; 380 mib[1] = KERN_ARND; 381 382 len = sizeof(__stack_chk_guard); 383 if (sysctl(mib, 2, __stack_chk_guard, &len, NULL, 0) == -1 || 384 len != sizeof(__stack_chk_guard)) { 385 /* If sysctl was unsuccessful, use the "terminator canary". */ 386 ((unsigned char *)(void *)__stack_chk_guard)[0] = 0; 387 ((unsigned char *)(void *)__stack_chk_guard)[1] = 0; 388 ((unsigned char *)(void *)__stack_chk_guard)[2] = '\n'; 389 ((unsigned char *)(void *)__stack_chk_guard)[3] = 255; 390 } 391 } 392 393 trust = !issetugid(); 394 395 ld_bind_now = getenv(LD_ "BIND_NOW"); 396 /* 397 * If the process is tainted, then we un-set the dangerous environment 398 * variables. The process will be marked as tainted until setuid(2) 399 * is called. If any child process calls setuid(2) we do not want any 400 * future processes to honor the potentially un-safe variables. 401 */ 402 if (!trust) { 403 if (unsetenv(LD_ "PRELOAD") || unsetenv(LD_ "LIBMAP") || 404 unsetenv(LD_ "LIBRARY_PATH") || unsetenv(LD_ "LIBMAP_DISABLE") || 405 unsetenv(LD_ "DEBUG") || unsetenv(LD_ "ELF_HINTS_PATH") || 406 unsetenv(LD_ "LOADFLTR") || unsetenv(LD_ "LIBRARY_PATH_RPATH")) { 407 _rtld_error("environment corrupt; aborting"); 408 die(); 409 } 410 } 411 ld_debug = getenv(LD_ "DEBUG"); 412 libmap_disable = getenv(LD_ "LIBMAP_DISABLE") != NULL; 413 libmap_override = getenv(LD_ "LIBMAP"); 414 ld_library_path = getenv(LD_ "LIBRARY_PATH"); 415 ld_preload = getenv(LD_ "PRELOAD"); 416 ld_elf_hints_path = getenv(LD_ "ELF_HINTS_PATH"); 417 ld_loadfltr = getenv(LD_ "LOADFLTR") != NULL; 418 library_path_rpath = getenv(LD_ "LIBRARY_PATH_RPATH"); 419 if (library_path_rpath != NULL) { 420 if (library_path_rpath[0] == 'y' || 421 library_path_rpath[0] == 'Y' || 422 library_path_rpath[0] == '1') 423 ld_library_path_rpath = true; 424 else 425 ld_library_path_rpath = false; 426 } 427 dangerous_ld_env = libmap_disable || (libmap_override != NULL) || 428 (ld_library_path != NULL) || (ld_preload != NULL) || 429 (ld_elf_hints_path != NULL) || ld_loadfltr; 430 ld_tracing = getenv(LD_ "TRACE_LOADED_OBJECTS"); 431 ld_utrace = getenv(LD_ "UTRACE"); 432 433 if ((ld_elf_hints_path == NULL) || strlen(ld_elf_hints_path) == 0) 434 ld_elf_hints_path = _PATH_ELF_HINTS; 435 436 if (ld_debug != NULL && *ld_debug != '\0') 437 debug = 1; 438 dbg("%s is initialized, base address = %p", __progname, 439 (caddr_t) aux_info[AT_BASE]->a_un.a_ptr); 440 dbg("RTLD dynamic = %p", obj_rtld.dynamic); 441 dbg("RTLD pltgot = %p", obj_rtld.pltgot); 442 443 dbg("initializing thread locks"); 444 lockdflt_init(); 445 446 /* 447 * Load the main program, or process its program header if it is 448 * already loaded. 449 */ 450 if (aux_info[AT_EXECFD] != NULL) { /* Load the main program. */ 451 int fd = aux_info[AT_EXECFD]->a_un.a_val; 452 dbg("loading main program"); 453 obj_main = map_object(fd, argv0, NULL); 454 close(fd); 455 if (obj_main == NULL) 456 die(); 457 max_stack_flags = obj->stack_flags; 458 } else { /* Main program already loaded. */ 459 const Elf_Phdr *phdr; 460 int phnum; 461 caddr_t entry; 462 463 dbg("processing main program's program header"); 464 assert(aux_info[AT_PHDR] != NULL); 465 phdr = (const Elf_Phdr *) aux_info[AT_PHDR]->a_un.a_ptr; 466 assert(aux_info[AT_PHNUM] != NULL); 467 phnum = aux_info[AT_PHNUM]->a_un.a_val; 468 assert(aux_info[AT_PHENT] != NULL); 469 assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr)); 470 assert(aux_info[AT_ENTRY] != NULL); 471 entry = (caddr_t) aux_info[AT_ENTRY]->a_un.a_ptr; 472 if ((obj_main = digest_phdr(phdr, phnum, entry, argv0)) == NULL) 473 die(); 474 } 475 476 if (aux_info[AT_EXECPATH] != 0) { 477 char *kexecpath; 478 char buf[MAXPATHLEN]; 479 480 kexecpath = aux_info[AT_EXECPATH]->a_un.a_ptr; 481 dbg("AT_EXECPATH %p %s", kexecpath, kexecpath); 482 if (kexecpath[0] == '/') 483 obj_main->path = kexecpath; 484 else if (getcwd(buf, sizeof(buf)) == NULL || 485 strlcat(buf, "/", sizeof(buf)) >= sizeof(buf) || 486 strlcat(buf, kexecpath, sizeof(buf)) >= sizeof(buf)) 487 obj_main->path = xstrdup(argv0); 488 else 489 obj_main->path = xstrdup(buf); 490 } else { 491 dbg("No AT_EXECPATH"); 492 obj_main->path = xstrdup(argv0); 493 } 494 dbg("obj_main path %s", obj_main->path); 495 obj_main->mainprog = true; 496 497 if (aux_info[AT_STACKPROT] != NULL && 498 aux_info[AT_STACKPROT]->a_un.a_val != 0) 499 stack_prot = aux_info[AT_STACKPROT]->a_un.a_val; 500 501#ifndef COMPAT_32BIT 502 /* 503 * Get the actual dynamic linker pathname from the executable if 504 * possible. (It should always be possible.) That ensures that 505 * gdb will find the right dynamic linker even if a non-standard 506 * one is being used. 507 */ 508 if (obj_main->interp != NULL && 509 strcmp(obj_main->interp, obj_rtld.path) != 0) { 510 free(obj_rtld.path); 511 obj_rtld.path = xstrdup(obj_main->interp); 512 __progname = obj_rtld.path; 513 } 514#endif 515 516 digest_dynamic(obj_main, 0); 517 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", 518 obj_main->path, obj_main->valid_hash_sysv, obj_main->valid_hash_gnu, 519 obj_main->dynsymcount); 520 521 linkmap_add(obj_main); 522 linkmap_add(&obj_rtld); 523 524 /* Link the main program into the list of objects. */ 525 *obj_tail = obj_main; 526 obj_tail = &obj_main->next; 527 obj_count++; 528 obj_loads++; 529 530 /* Initialize a fake symbol for resolving undefined weak references. */ 531 sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE); 532 sym_zero.st_shndx = SHN_UNDEF; 533 sym_zero.st_value = -(uintptr_t)obj_main->relocbase; 534 535 if (!libmap_disable) 536 libmap_disable = (bool)lm_init(libmap_override); 537 538 dbg("loading LD_PRELOAD libraries"); 539 if (load_preload_objects() == -1) 540 die(); 541 preload_tail = obj_tail; 542 543 dbg("loading needed objects"); 544 if (load_needed_objects(obj_main, 0) == -1) 545 die(); 546 547 /* Make a list of all objects loaded at startup. */ 548 last_interposer = obj_main; 549 for (obj = obj_list; obj != NULL; obj = obj->next) { 550 if (obj->z_interpose && obj != obj_main) { 551 objlist_put_after(&list_main, last_interposer, obj); 552 last_interposer = obj; 553 } else { 554 objlist_push_tail(&list_main, obj); 555 } 556 obj->refcount++; 557 } 558 559 dbg("checking for required versions"); 560 if (rtld_verify_versions(&list_main) == -1 && !ld_tracing) 561 die(); 562 563 if (ld_tracing) { /* We're done */ 564 trace_loaded_objects(obj_main); 565 exit(0); 566 } 567 568 if (getenv(LD_ "DUMP_REL_PRE") != NULL) { 569 dump_relocations(obj_main); 570 exit (0); 571 } 572 573 /* 574 * Processing tls relocations requires having the tls offsets 575 * initialized. Prepare offsets before starting initial 576 * relocation processing. 577 */ 578 dbg("initializing initial thread local storage offsets"); 579 STAILQ_FOREACH(entry, &list_main, link) { 580 /* 581 * Allocate all the initial objects out of the static TLS 582 * block even if they didn't ask for it. 583 */ 584 allocate_tls_offset(entry->obj); 585 } 586 587 if (relocate_objects(obj_main, 588 ld_bind_now != NULL && *ld_bind_now != '\0', 589 &obj_rtld, SYMLOOK_EARLY, NULL) == -1) 590 die(); 591 592 dbg("doing copy relocations"); 593 if (do_copy_relocations(obj_main) == -1) 594 die(); 595 596 if (getenv(LD_ "DUMP_REL_POST") != NULL) { 597 dump_relocations(obj_main); 598 exit (0); 599 } 600 601 /* 602 * Setup TLS for main thread. This must be done after the 603 * relocations are processed, since tls initialization section 604 * might be the subject for relocations. 605 */ 606 dbg("initializing initial thread local storage"); 607 allocate_initial_tls(obj_list); 608 609 dbg("initializing key program variables"); 610 set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : ""); 611 set_program_var("environ", env); 612 set_program_var("__elf_aux_vector", aux); 613 614 /* Make a list of init functions to call. */ 615 objlist_init(&initlist); 616 initlist_add_objects(obj_list, preload_tail, &initlist); 617 618 r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */ 619 620 map_stacks_exec(NULL); 621 622 dbg("resolving ifuncs"); 623 if (resolve_objects_ifunc(obj_main, 624 ld_bind_now != NULL && *ld_bind_now != '\0', SYMLOOK_EARLY, 625 NULL) == -1) 626 die(); 627 628 if (!obj_main->crt_no_init) { 629 /* 630 * Make sure we don't call the main program's init and fini 631 * functions for binaries linked with old crt1 which calls 632 * _init itself. 633 */ 634 obj_main->init = obj_main->fini = (Elf_Addr)NULL; 635 obj_main->preinit_array = obj_main->init_array = 636 obj_main->fini_array = (Elf_Addr)NULL; 637 } 638 639 wlock_acquire(rtld_bind_lock, &lockstate); 640 if (obj_main->crt_no_init) 641 preinit_main(); 642 objlist_call_init(&initlist, &lockstate); 643 _r_debug_postinit(&obj_main->linkmap); 644 objlist_clear(&initlist); 645 dbg("loading filtees"); 646 for (obj = obj_list->next; obj != NULL; obj = obj->next) { 647 if (ld_loadfltr || obj->z_loadfltr) 648 load_filtees(obj, 0, &lockstate); 649 } 650 lock_release(rtld_bind_lock, &lockstate); 651 652 dbg("transferring control to program entry point = %p", obj_main->entry); 653 654 /* Return the exit procedure and the program entry point. */ 655 *exit_proc = rtld_exit; 656 *objp = obj_main; 657 return (func_ptr_type) obj_main->entry; 658} 659 660void * 661rtld_resolve_ifunc(const Obj_Entry *obj, const Elf_Sym *def) 662{ 663 void *ptr; 664 Elf_Addr target; 665 666 ptr = (void *)make_function_pointer(def, obj); 667 target = ((Elf_Addr (*)(void))ptr)(); 668 return ((void *)target); 669} 670 671Elf_Addr 672_rtld_bind(Obj_Entry *obj, Elf_Size reloff) 673{ 674 const Elf_Rel *rel; 675 const Elf_Sym *def; 676 const Obj_Entry *defobj; 677 Elf_Addr *where; 678 Elf_Addr target; 679 RtldLockState lockstate; 680 681 rlock_acquire(rtld_bind_lock, &lockstate); 682 if (sigsetjmp(lockstate.env, 0) != 0) 683 lock_upgrade(rtld_bind_lock, &lockstate); 684 if (obj->pltrel) 685 rel = (const Elf_Rel *) ((caddr_t) obj->pltrel + reloff); 686 else 687 rel = (const Elf_Rel *) ((caddr_t) obj->pltrela + reloff); 688 689 where = (Elf_Addr *) (obj->relocbase + rel->r_offset); 690 def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, true, NULL, 691 &lockstate); 692 if (def == NULL) 693 die(); 694 if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 695 target = (Elf_Addr)rtld_resolve_ifunc(defobj, def); 696 else 697 target = (Elf_Addr)(defobj->relocbase + def->st_value); 698 699 dbg("\"%s\" in \"%s\" ==> %p in \"%s\"", 700 defobj->strtab + def->st_name, basename(obj->path), 701 (void *)target, basename(defobj->path)); 702 703 /* 704 * Write the new contents for the jmpslot. Note that depending on 705 * architecture, the value which we need to return back to the 706 * lazy binding trampoline may or may not be the target 707 * address. The value returned from reloc_jmpslot() is the value 708 * that the trampoline needs. 709 */ 710 target = reloc_jmpslot(where, target, defobj, obj, rel); 711 lock_release(rtld_bind_lock, &lockstate); 712 return target; 713} 714 715/* 716 * Error reporting function. Use it like printf. If formats the message 717 * into a buffer, and sets things up so that the next call to dlerror() 718 * will return the message. 719 */ 720void 721_rtld_error(const char *fmt, ...) 722{ 723 static char buf[512]; 724 va_list ap; 725 726 va_start(ap, fmt); 727 rtld_vsnprintf(buf, sizeof buf, fmt, ap); 728 error_message = buf; 729 va_end(ap); 730} 731 732/* 733 * Return a dynamically-allocated copy of the current error message, if any. 734 */ 735static char * 736errmsg_save(void) 737{ 738 return error_message == NULL ? NULL : xstrdup(error_message); 739} 740 741/* 742 * Restore the current error message from a copy which was previously saved 743 * by errmsg_save(). The copy is freed. 744 */ 745static void 746errmsg_restore(char *saved_msg) 747{ 748 if (saved_msg == NULL) 749 error_message = NULL; 750 else { 751 _rtld_error("%s", saved_msg); 752 free(saved_msg); 753 } 754} 755 756static const char * 757basename(const char *name) 758{ 759 const char *p = strrchr(name, '/'); 760 return p != NULL ? p + 1 : name; 761} 762 763static struct utsname uts; 764 765static char * 766origin_subst_one(char *real, const char *kw, const char *subst, 767 bool may_free) 768{ 769 char *p, *p1, *res, *resp; 770 int subst_len, kw_len, subst_count, old_len, new_len; 771 772 kw_len = strlen(kw); 773 774 /* 775 * First, count the number of the keyword occurences, to 776 * preallocate the final string. 777 */ 778 for (p = real, subst_count = 0;; p = p1 + kw_len, subst_count++) { 779 p1 = strstr(p, kw); 780 if (p1 == NULL) 781 break; 782 } 783 784 /* 785 * If the keyword is not found, just return. 786 */ 787 if (subst_count == 0) 788 return (may_free ? real : xstrdup(real)); 789 790 /* 791 * There is indeed something to substitute. Calculate the 792 * length of the resulting string, and allocate it. 793 */ 794 subst_len = strlen(subst); 795 old_len = strlen(real); 796 new_len = old_len + (subst_len - kw_len) * subst_count; 797 res = xmalloc(new_len + 1); 798 799 /* 800 * Now, execute the substitution loop. 801 */ 802 for (p = real, resp = res, *resp = '\0';;) { 803 p1 = strstr(p, kw); 804 if (p1 != NULL) { 805 /* Copy the prefix before keyword. */ 806 memcpy(resp, p, p1 - p); 807 resp += p1 - p; 808 /* Keyword replacement. */ 809 memcpy(resp, subst, subst_len); 810 resp += subst_len; 811 *resp = '\0'; 812 p = p1 + kw_len; 813 } else 814 break; 815 } 816 817 /* Copy to the end of string and finish. */ 818 strcat(resp, p); 819 if (may_free) 820 free(real); 821 return (res); 822} 823 824static char * 825origin_subst(char *real, const char *origin_path) 826{ 827 char *res1, *res2, *res3, *res4; 828 829 if (uts.sysname[0] == '\0') { 830 if (uname(&uts) != 0) { 831 _rtld_error("utsname failed: %d", errno); 832 return (NULL); 833 } 834 } 835 res1 = origin_subst_one(real, "$ORIGIN", origin_path, false); 836 res2 = origin_subst_one(res1, "$OSNAME", uts.sysname, true); 837 res3 = origin_subst_one(res2, "$OSREL", uts.release, true); 838 res4 = origin_subst_one(res3, "$PLATFORM", uts.machine, true); 839 return (res4); 840} 841 842static void 843die(void) 844{ 845 const char *msg = dlerror(); 846 847 if (msg == NULL) 848 msg = "Fatal error"; 849 rtld_fdputstr(STDERR_FILENO, msg); 850 rtld_fdputchar(STDERR_FILENO, '\n'); 851 _exit(1); 852} 853 854/* 855 * Process a shared object's DYNAMIC section, and save the important 856 * information in its Obj_Entry structure. 857 */ 858static void 859digest_dynamic1(Obj_Entry *obj, int early, const Elf_Dyn **dyn_rpath, 860 const Elf_Dyn **dyn_soname, const Elf_Dyn **dyn_runpath) 861{ 862 const Elf_Dyn *dynp; 863 Needed_Entry **needed_tail = &obj->needed; 864 Needed_Entry **needed_filtees_tail = &obj->needed_filtees; 865 Needed_Entry **needed_aux_filtees_tail = &obj->needed_aux_filtees; 866 const Elf_Hashelt *hashtab; 867 const Elf32_Word *hashval; 868 Elf32_Word bkt, nmaskwords; 869 int bloom_size32; 870 int plttype = DT_REL; 871 872 *dyn_rpath = NULL; 873 *dyn_soname = NULL; 874 *dyn_runpath = NULL; 875 876 obj->bind_now = false; 877 for (dynp = obj->dynamic; dynp->d_tag != DT_NULL; dynp++) { 878 switch (dynp->d_tag) { 879 880 case DT_REL: 881 obj->rel = (const Elf_Rel *) (obj->relocbase + dynp->d_un.d_ptr); 882 break; 883 884 case DT_RELSZ: 885 obj->relsize = dynp->d_un.d_val; 886 break; 887 888 case DT_RELENT: 889 assert(dynp->d_un.d_val == sizeof(Elf_Rel)); 890 break; 891 892 case DT_JMPREL: 893 obj->pltrel = (const Elf_Rel *) 894 (obj->relocbase + dynp->d_un.d_ptr); 895 break; 896 897 case DT_PLTRELSZ: 898 obj->pltrelsize = dynp->d_un.d_val; 899 break; 900 901 case DT_RELA: 902 obj->rela = (const Elf_Rela *) (obj->relocbase + dynp->d_un.d_ptr); 903 break; 904 905 case DT_RELASZ: 906 obj->relasize = dynp->d_un.d_val; 907 break; 908 909 case DT_RELAENT: 910 assert(dynp->d_un.d_val == sizeof(Elf_Rela)); 911 break; 912 913 case DT_PLTREL: 914 plttype = dynp->d_un.d_val; 915 assert(dynp->d_un.d_val == DT_REL || plttype == DT_RELA); 916 break; 917 918 case DT_SYMTAB: 919 obj->symtab = (const Elf_Sym *) 920 (obj->relocbase + dynp->d_un.d_ptr); 921 break; 922 923 case DT_SYMENT: 924 assert(dynp->d_un.d_val == sizeof(Elf_Sym)); 925 break; 926 927 case DT_STRTAB: 928 obj->strtab = (const char *) (obj->relocbase + dynp->d_un.d_ptr); 929 break; 930 931 case DT_STRSZ: 932 obj->strsize = dynp->d_un.d_val; 933 break; 934 935 case DT_VERNEED: 936 obj->verneed = (const Elf_Verneed *) (obj->relocbase + 937 dynp->d_un.d_val); 938 break; 939 940 case DT_VERNEEDNUM: 941 obj->verneednum = dynp->d_un.d_val; 942 break; 943 944 case DT_VERDEF: 945 obj->verdef = (const Elf_Verdef *) (obj->relocbase + 946 dynp->d_un.d_val); 947 break; 948 949 case DT_VERDEFNUM: 950 obj->verdefnum = dynp->d_un.d_val; 951 break; 952 953 case DT_VERSYM: 954 obj->versyms = (const Elf_Versym *)(obj->relocbase + 955 dynp->d_un.d_val); 956 break; 957 958 case DT_HASH: 959 { 960 hashtab = (const Elf_Hashelt *)(obj->relocbase + 961 dynp->d_un.d_ptr); 962 obj->nbuckets = hashtab[0]; 963 obj->nchains = hashtab[1]; 964 obj->buckets = hashtab + 2; 965 obj->chains = obj->buckets + obj->nbuckets; 966 obj->valid_hash_sysv = obj->nbuckets > 0 && obj->nchains > 0 && 967 obj->buckets != NULL; 968 } 969 break; 970 971 case DT_GNU_HASH: 972 { 973 hashtab = (const Elf_Hashelt *)(obj->relocbase + 974 dynp->d_un.d_ptr); 975 obj->nbuckets_gnu = hashtab[0]; 976 obj->symndx_gnu = hashtab[1]; 977 nmaskwords = hashtab[2]; 978 bloom_size32 = (__ELF_WORD_SIZE / 32) * nmaskwords; 979 obj->maskwords_bm_gnu = nmaskwords - 1; 980 obj->shift2_gnu = hashtab[3]; 981 obj->bloom_gnu = (Elf_Addr *) (hashtab + 4); 982 obj->buckets_gnu = hashtab + 4 + bloom_size32; 983 obj->chain_zero_gnu = obj->buckets_gnu + obj->nbuckets_gnu - 984 obj->symndx_gnu; 985 /* Number of bitmask words is required to be power of 2 */ 986 obj->valid_hash_gnu = powerof2(nmaskwords) && 987 obj->nbuckets_gnu > 0 && obj->buckets_gnu != NULL; 988 } 989 break; 990 991 case DT_NEEDED: 992 if (!obj->rtld) { 993 Needed_Entry *nep = NEW(Needed_Entry); 994 nep->name = dynp->d_un.d_val; 995 nep->obj = NULL; 996 nep->next = NULL; 997 998 *needed_tail = nep; 999 needed_tail = &nep->next; 1000 } 1001 break; 1002 1003 case DT_FILTER: 1004 if (!obj->rtld) { 1005 Needed_Entry *nep = NEW(Needed_Entry); 1006 nep->name = dynp->d_un.d_val; 1007 nep->obj = NULL; 1008 nep->next = NULL; 1009 1010 *needed_filtees_tail = nep; 1011 needed_filtees_tail = &nep->next; 1012 } 1013 break; 1014 1015 case DT_AUXILIARY: 1016 if (!obj->rtld) { 1017 Needed_Entry *nep = NEW(Needed_Entry); 1018 nep->name = dynp->d_un.d_val; 1019 nep->obj = NULL; 1020 nep->next = NULL; 1021 1022 *needed_aux_filtees_tail = nep; 1023 needed_aux_filtees_tail = &nep->next; 1024 } 1025 break; 1026 1027 case DT_PLTGOT: 1028 obj->pltgot = (Elf_Addr *) (obj->relocbase + dynp->d_un.d_ptr); 1029 break; 1030 1031 case DT_TEXTREL: 1032 obj->textrel = true; 1033 break; 1034 1035 case DT_SYMBOLIC: 1036 obj->symbolic = true; 1037 break; 1038 1039 case DT_RPATH: 1040 /* 1041 * We have to wait until later to process this, because we 1042 * might not have gotten the address of the string table yet. 1043 */ 1044 *dyn_rpath = dynp; 1045 break; 1046 1047 case DT_SONAME: 1048 *dyn_soname = dynp; 1049 break; 1050 1051 case DT_RUNPATH: 1052 *dyn_runpath = dynp; 1053 break; 1054 1055 case DT_INIT: 1056 obj->init = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr); 1057 break; 1058 1059 case DT_PREINIT_ARRAY: 1060 obj->preinit_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1061 break; 1062 1063 case DT_PREINIT_ARRAYSZ: 1064 obj->preinit_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1065 break; 1066 1067 case DT_INIT_ARRAY: 1068 obj->init_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1069 break; 1070 1071 case DT_INIT_ARRAYSZ: 1072 obj->init_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1073 break; 1074 1075 case DT_FINI: 1076 obj->fini = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr); 1077 break; 1078 1079 case DT_FINI_ARRAY: 1080 obj->fini_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr); 1081 break; 1082 1083 case DT_FINI_ARRAYSZ: 1084 obj->fini_array_num = dynp->d_un.d_val / sizeof(Elf_Addr); 1085 break; 1086 1087 /* 1088 * Don't process DT_DEBUG on MIPS as the dynamic section 1089 * is mapped read-only. DT_MIPS_RLD_MAP is used instead. 1090 */ 1091 1092#ifndef __mips__ 1093 case DT_DEBUG: 1094 /* XXX - not implemented yet */ 1095 if (!early) 1096 dbg("Filling in DT_DEBUG entry"); 1097 ((Elf_Dyn*)dynp)->d_un.d_ptr = (Elf_Addr) &r_debug; 1098 break; 1099#endif 1100 1101 case DT_FLAGS: 1102 if ((dynp->d_un.d_val & DF_ORIGIN) && trust) 1103 obj->z_origin = true; 1104 if (dynp->d_un.d_val & DF_SYMBOLIC) 1105 obj->symbolic = true; 1106 if (dynp->d_un.d_val & DF_TEXTREL) 1107 obj->textrel = true; 1108 if (dynp->d_un.d_val & DF_BIND_NOW) 1109 obj->bind_now = true; 1110 /*if (dynp->d_un.d_val & DF_STATIC_TLS) 1111 ;*/ 1112 break; 1113#ifdef __mips__ 1114 case DT_MIPS_LOCAL_GOTNO: 1115 obj->local_gotno = dynp->d_un.d_val; 1116 break; 1117 1118 case DT_MIPS_SYMTABNO: 1119 obj->symtabno = dynp->d_un.d_val; 1120 break; 1121 1122 case DT_MIPS_GOTSYM: 1123 obj->gotsym = dynp->d_un.d_val; 1124 break; 1125 1126 case DT_MIPS_RLD_MAP: 1127 *((Elf_Addr *)(dynp->d_un.d_ptr)) = (Elf_Addr) &r_debug; 1128 break; 1129#endif 1130 1131 case DT_FLAGS_1: 1132 if (dynp->d_un.d_val & DF_1_NOOPEN) 1133 obj->z_noopen = true; 1134 if ((dynp->d_un.d_val & DF_1_ORIGIN) && trust) 1135 obj->z_origin = true; 1136 /*if (dynp->d_un.d_val & DF_1_GLOBAL) 1137 XXX ;*/ 1138 if (dynp->d_un.d_val & DF_1_BIND_NOW) 1139 obj->bind_now = true; 1140 if (dynp->d_un.d_val & DF_1_NODELETE) 1141 obj->z_nodelete = true; 1142 if (dynp->d_un.d_val & DF_1_LOADFLTR) 1143 obj->z_loadfltr = true; 1144 if (dynp->d_un.d_val & DF_1_INTERPOSE) 1145 obj->z_interpose = true; 1146 if (dynp->d_un.d_val & DF_1_NODEFLIB) 1147 obj->z_nodeflib = true; 1148 break; 1149 1150 default: 1151 if (!early) { 1152 dbg("Ignoring d_tag %ld = %#lx", (long)dynp->d_tag, 1153 (long)dynp->d_tag); 1154 } 1155 break; 1156 } 1157 } 1158 1159 obj->traced = false; 1160 1161 if (plttype == DT_RELA) { 1162 obj->pltrela = (const Elf_Rela *) obj->pltrel; 1163 obj->pltrel = NULL; 1164 obj->pltrelasize = obj->pltrelsize; 1165 obj->pltrelsize = 0; 1166 } 1167 1168 /* Determine size of dynsym table (equal to nchains of sysv hash) */ 1169 if (obj->valid_hash_sysv) 1170 obj->dynsymcount = obj->nchains; 1171 else if (obj->valid_hash_gnu) { 1172 obj->dynsymcount = 0; 1173 for (bkt = 0; bkt < obj->nbuckets_gnu; bkt++) { 1174 if (obj->buckets_gnu[bkt] == 0) 1175 continue; 1176 hashval = &obj->chain_zero_gnu[obj->buckets_gnu[bkt]]; 1177 do 1178 obj->dynsymcount++; 1179 while ((*hashval++ & 1u) == 0); 1180 } 1181 obj->dynsymcount += obj->symndx_gnu; 1182 } 1183} 1184 1185static void 1186digest_dynamic2(Obj_Entry *obj, const Elf_Dyn *dyn_rpath, 1187 const Elf_Dyn *dyn_soname, const Elf_Dyn *dyn_runpath) 1188{ 1189 1190 if (obj->z_origin && obj->origin_path == NULL) { 1191 obj->origin_path = xmalloc(PATH_MAX); 1192 if (rtld_dirname_abs(obj->path, obj->origin_path) == -1) 1193 die(); 1194 } 1195 1196 if (dyn_runpath != NULL) { 1197 obj->runpath = (char *)obj->strtab + dyn_runpath->d_un.d_val; 1198 if (obj->z_origin) 1199 obj->runpath = origin_subst(obj->runpath, obj->origin_path); 1200 } 1201 else if (dyn_rpath != NULL) { 1202 obj->rpath = (char *)obj->strtab + dyn_rpath->d_un.d_val; 1203 if (obj->z_origin) 1204 obj->rpath = origin_subst(obj->rpath, obj->origin_path); 1205 } 1206 1207 if (dyn_soname != NULL) 1208 object_add_name(obj, obj->strtab + dyn_soname->d_un.d_val); 1209} 1210 1211static void 1212digest_dynamic(Obj_Entry *obj, int early) 1213{ 1214 const Elf_Dyn *dyn_rpath; 1215 const Elf_Dyn *dyn_soname; 1216 const Elf_Dyn *dyn_runpath; 1217 1218 digest_dynamic1(obj, early, &dyn_rpath, &dyn_soname, &dyn_runpath); 1219 digest_dynamic2(obj, dyn_rpath, dyn_soname, dyn_runpath); 1220} 1221 1222/* 1223 * Process a shared object's program header. This is used only for the 1224 * main program, when the kernel has already loaded the main program 1225 * into memory before calling the dynamic linker. It creates and 1226 * returns an Obj_Entry structure. 1227 */ 1228static Obj_Entry * 1229digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path) 1230{ 1231 Obj_Entry *obj; 1232 const Elf_Phdr *phlimit = phdr + phnum; 1233 const Elf_Phdr *ph; 1234 Elf_Addr note_start, note_end; 1235 int nsegs = 0; 1236 1237 obj = obj_new(); 1238 for (ph = phdr; ph < phlimit; ph++) { 1239 if (ph->p_type != PT_PHDR) 1240 continue; 1241 1242 obj->phdr = phdr; 1243 obj->phsize = ph->p_memsz; 1244 obj->relocbase = (caddr_t)phdr - ph->p_vaddr; 1245 break; 1246 } 1247 1248 obj->stack_flags = PF_X | PF_R | PF_W; 1249 1250 for (ph = phdr; ph < phlimit; ph++) { 1251 switch (ph->p_type) { 1252 1253 case PT_INTERP: 1254 obj->interp = (const char *)(ph->p_vaddr + obj->relocbase); 1255 break; 1256 1257 case PT_LOAD: 1258 if (nsegs == 0) { /* First load segment */ 1259 obj->vaddrbase = trunc_page(ph->p_vaddr); 1260 obj->mapbase = obj->vaddrbase + obj->relocbase; 1261 obj->textsize = round_page(ph->p_vaddr + ph->p_memsz) - 1262 obj->vaddrbase; 1263 } else { /* Last load segment */ 1264 obj->mapsize = round_page(ph->p_vaddr + ph->p_memsz) - 1265 obj->vaddrbase; 1266 } 1267 nsegs++; 1268 break; 1269 1270 case PT_DYNAMIC: 1271 obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + obj->relocbase); 1272 break; 1273 1274 case PT_TLS: 1275 obj->tlsindex = 1; 1276 obj->tlssize = ph->p_memsz; 1277 obj->tlsalign = ph->p_align; 1278 obj->tlsinitsize = ph->p_filesz; 1279 obj->tlsinit = (void*)(ph->p_vaddr + obj->relocbase); 1280 break; 1281 1282 case PT_GNU_STACK: 1283 obj->stack_flags = ph->p_flags; 1284 break; 1285 1286 case PT_GNU_RELRO: 1287 obj->relro_page = obj->relocbase + trunc_page(ph->p_vaddr); 1288 obj->relro_size = round_page(ph->p_memsz); 1289 break; 1290 1291 case PT_NOTE: 1292 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr; 1293 note_end = note_start + ph->p_filesz; 1294 digest_notes(obj, note_start, note_end); 1295 break; 1296 } 1297 } 1298 if (nsegs < 1) { 1299 _rtld_error("%s: too few PT_LOAD segments", path); 1300 return NULL; 1301 } 1302 1303 obj->entry = entry; 1304 return obj; 1305} 1306 1307void 1308digest_notes(Obj_Entry *obj, Elf_Addr note_start, Elf_Addr note_end) 1309{ 1310 const Elf_Note *note; 1311 const char *note_name; 1312 uintptr_t p; 1313 1314 for (note = (const Elf_Note *)note_start; (Elf_Addr)note < note_end; 1315 note = (const Elf_Note *)((const char *)(note + 1) + 1316 roundup2(note->n_namesz, sizeof(Elf32_Addr)) + 1317 roundup2(note->n_descsz, sizeof(Elf32_Addr)))) { 1318 if (note->n_namesz != sizeof(NOTE_FREEBSD_VENDOR) || 1319 note->n_descsz != sizeof(int32_t)) 1320 continue; 1321 if (note->n_type != ABI_NOTETYPE && 1322 note->n_type != CRT_NOINIT_NOTETYPE) 1323 continue; 1324 note_name = (const char *)(note + 1); 1325 if (strncmp(NOTE_FREEBSD_VENDOR, note_name, 1326 sizeof(NOTE_FREEBSD_VENDOR)) != 0) 1327 continue; 1328 switch (note->n_type) { 1329 case ABI_NOTETYPE: 1330 /* FreeBSD osrel note */ 1331 p = (uintptr_t)(note + 1); 1332 p += roundup2(note->n_namesz, sizeof(Elf32_Addr)); 1333 obj->osrel = *(const int32_t *)(p); 1334 dbg("note osrel %d", obj->osrel); 1335 break; 1336 case CRT_NOINIT_NOTETYPE: 1337 /* FreeBSD 'crt does not call init' note */ 1338 obj->crt_no_init = true; 1339 dbg("note crt_no_init"); 1340 break; 1341 } 1342 } 1343} 1344 1345static Obj_Entry * 1346dlcheck(void *handle) 1347{ 1348 Obj_Entry *obj; 1349 1350 for (obj = obj_list; obj != NULL; obj = obj->next) 1351 if (obj == (Obj_Entry *) handle) 1352 break; 1353 1354 if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) { 1355 _rtld_error("Invalid shared object handle %p", handle); 1356 return NULL; 1357 } 1358 return obj; 1359} 1360 1361/* 1362 * If the given object is already in the donelist, return true. Otherwise 1363 * add the object to the list and return false. 1364 */ 1365static bool 1366donelist_check(DoneList *dlp, const Obj_Entry *obj) 1367{ 1368 unsigned int i; 1369 1370 for (i = 0; i < dlp->num_used; i++) 1371 if (dlp->objs[i] == obj) 1372 return true; 1373 /* 1374 * Our donelist allocation should always be sufficient. But if 1375 * our threads locking isn't working properly, more shared objects 1376 * could have been loaded since we allocated the list. That should 1377 * never happen, but we'll handle it properly just in case it does. 1378 */ 1379 if (dlp->num_used < dlp->num_alloc) 1380 dlp->objs[dlp->num_used++] = obj; 1381 return false; 1382} 1383 1384/* 1385 * Hash function for symbol table lookup. Don't even think about changing 1386 * this. It is specified by the System V ABI. 1387 */ 1388unsigned long 1389elf_hash(const char *name) 1390{ 1391 const unsigned char *p = (const unsigned char *) name; 1392 unsigned long h = 0; 1393 unsigned long g; 1394 1395 while (*p != '\0') { 1396 h = (h << 4) + *p++; 1397 if ((g = h & 0xf0000000) != 0) 1398 h ^= g >> 24; 1399 h &= ~g; 1400 } 1401 return h; 1402} 1403 1404/* 1405 * The GNU hash function is the Daniel J. Bernstein hash clipped to 32 bits 1406 * unsigned in case it's implemented with a wider type. 1407 */ 1408static uint32_t 1409gnu_hash(const char *s) 1410{ 1411 uint32_t h; 1412 unsigned char c; 1413 1414 h = 5381; 1415 for (c = *s; c != '\0'; c = *++s) 1416 h = h * 33 + c; 1417 return (h & 0xffffffff); 1418} 1419 1420/* 1421 * Find the library with the given name, and return its full pathname. 1422 * The returned string is dynamically allocated. Generates an error 1423 * message and returns NULL if the library cannot be found. 1424 * 1425 * If the second argument is non-NULL, then it refers to an already- 1426 * loaded shared object, whose library search path will be searched. 1427 * 1428 * The search order is: 1429 * DT_RPATH in the referencing file _unless_ DT_RUNPATH is present (1) 1430 * DT_RPATH of the main object if DSO without defined DT_RUNPATH (1) 1431 * LD_LIBRARY_PATH 1432 * DT_RUNPATH in the referencing file 1433 * ldconfig hints (if -z nodefaultlib, filter out default library directories 1434 * from list) 1435 * /lib:/usr/lib _unless_ the referencing file is linked with -z nodefaultlib 1436 * 1437 * (1) Handled in digest_dynamic2 - rpath left NULL if runpath defined. 1438 */ 1439static char * 1440find_library(const char *xname, const Obj_Entry *refobj) 1441{ 1442 char *pathname; 1443 char *name; 1444 bool nodeflib, objgiven; 1445 1446 objgiven = refobj != NULL; 1447 if (strchr(xname, '/') != NULL) { /* Hard coded pathname */ 1448 if (xname[0] != '/' && !trust) { 1449 _rtld_error("Absolute pathname required for shared object \"%s\"", 1450 xname); 1451 return NULL; 1452 } 1453 if (objgiven && refobj->z_origin) { 1454 return (origin_subst(__DECONST(char *, xname), 1455 refobj->origin_path)); 1456 } else { 1457 return (xstrdup(xname)); 1458 } 1459 } 1460 1461 if (libmap_disable || !objgiven || 1462 (name = lm_find(refobj->path, xname)) == NULL) 1463 name = (char *)xname; 1464 1465 dbg(" Searching for \"%s\"", name); 1466 1467 /* 1468 * If refobj->rpath != NULL, then refobj->runpath is NULL. Fall 1469 * back to pre-conforming behaviour if user requested so with 1470 * LD_LIBRARY_PATH_RPATH environment variable and ignore -z 1471 * nodeflib. 1472 */ 1473 if (objgiven && refobj->rpath != NULL && ld_library_path_rpath) { 1474 if ((pathname = search_library_path(name, ld_library_path)) != NULL || 1475 (refobj != NULL && 1476 (pathname = search_library_path(name, refobj->rpath)) != NULL) || 1477 (pathname = search_library_path(name, gethints(false))) != NULL || 1478 (pathname = search_library_path(name, STANDARD_LIBRARY_PATH)) != NULL) 1479 return (pathname); 1480 } else { 1481 nodeflib = objgiven ? refobj->z_nodeflib : false; 1482 if ((objgiven && 1483 (pathname = search_library_path(name, refobj->rpath)) != NULL) || 1484 (objgiven && refobj->runpath == NULL && refobj != obj_main && 1485 (pathname = search_library_path(name, obj_main->rpath)) != NULL) || 1486 (pathname = search_library_path(name, ld_library_path)) != NULL || 1487 (objgiven && 1488 (pathname = search_library_path(name, refobj->runpath)) != NULL) || 1489 (pathname = search_library_path(name, gethints(nodeflib))) != NULL || 1490 (objgiven && !nodeflib && 1491 (pathname = search_library_path(name, STANDARD_LIBRARY_PATH)) != NULL)) 1492 return (pathname); 1493 } 1494 1495 if (objgiven && refobj->path != NULL) { 1496 _rtld_error("Shared object \"%s\" not found, required by \"%s\"", 1497 name, basename(refobj->path)); 1498 } else { 1499 _rtld_error("Shared object \"%s\" not found", name); 1500 } 1501 return NULL; 1502} 1503 1504/* 1505 * Given a symbol number in a referencing object, find the corresponding 1506 * definition of the symbol. Returns a pointer to the symbol, or NULL if 1507 * no definition was found. Returns a pointer to the Obj_Entry of the 1508 * defining object via the reference parameter DEFOBJ_OUT. 1509 */ 1510const Elf_Sym * 1511find_symdef(unsigned long symnum, const Obj_Entry *refobj, 1512 const Obj_Entry **defobj_out, int flags, SymCache *cache, 1513 RtldLockState *lockstate) 1514{ 1515 const Elf_Sym *ref; 1516 const Elf_Sym *def; 1517 const Obj_Entry *defobj; 1518 SymLook req; 1519 const char *name; 1520 int res; 1521 1522 /* 1523 * If we have already found this symbol, get the information from 1524 * the cache. 1525 */ 1526 if (symnum >= refobj->dynsymcount) 1527 return NULL; /* Bad object */ 1528 if (cache != NULL && cache[symnum].sym != NULL) { 1529 *defobj_out = cache[symnum].obj; 1530 return cache[symnum].sym; 1531 } 1532 1533 ref = refobj->symtab + symnum; 1534 name = refobj->strtab + ref->st_name; 1535 def = NULL; 1536 defobj = NULL; 1537 1538 /* 1539 * We don't have to do a full scale lookup if the symbol is local. 1540 * We know it will bind to the instance in this load module; to 1541 * which we already have a pointer (ie ref). By not doing a lookup, 1542 * we not only improve performance, but it also avoids unresolvable 1543 * symbols when local symbols are not in the hash table. This has 1544 * been seen with the ia64 toolchain. 1545 */ 1546 if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) { 1547 if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) { 1548 _rtld_error("%s: Bogus symbol table entry %lu", refobj->path, 1549 symnum); 1550 } 1551 symlook_init(&req, name); 1552 req.flags = flags; 1553 req.ventry = fetch_ventry(refobj, symnum); 1554 req.lockstate = lockstate; 1555 res = symlook_default(&req, refobj); 1556 if (res == 0) { 1557 def = req.sym_out; 1558 defobj = req.defobj_out; 1559 } 1560 } else { 1561 def = ref; 1562 defobj = refobj; 1563 } 1564 1565 /* 1566 * If we found no definition and the reference is weak, treat the 1567 * symbol as having the value zero. 1568 */ 1569 if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) { 1570 def = &sym_zero; 1571 defobj = obj_main; 1572 } 1573 1574 if (def != NULL) { 1575 *defobj_out = defobj; 1576 /* Record the information in the cache to avoid subsequent lookups. */ 1577 if (cache != NULL) { 1578 cache[symnum].sym = def; 1579 cache[symnum].obj = defobj; 1580 } 1581 } else { 1582 if (refobj != &obj_rtld) 1583 _rtld_error("%s: Undefined symbol \"%s\"", refobj->path, name); 1584 } 1585 return def; 1586} 1587 1588/* 1589 * Return the search path from the ldconfig hints file, reading it if 1590 * necessary. If nostdlib is true, then the default search paths are 1591 * not added to result. 1592 * 1593 * Returns NULL if there are problems with the hints file, 1594 * or if the search path there is empty. 1595 */ 1596static const char * 1597gethints(bool nostdlib) 1598{ 1599 static char *hints, *filtered_path; 1600 struct elfhints_hdr hdr; 1601 struct fill_search_info_args sargs, hargs; 1602 struct dl_serinfo smeta, hmeta, *SLPinfo, *hintinfo; 1603 struct dl_serpath *SLPpath, *hintpath; 1604 char *p; 1605 unsigned int SLPndx, hintndx, fndx, fcount; 1606 int fd; 1607 size_t flen; 1608 bool skip; 1609 1610 /* First call, read the hints file */ 1611 if (hints == NULL) { 1612 /* Keep from trying again in case the hints file is bad. */ 1613 hints = ""; 1614 1615 if ((fd = open(ld_elf_hints_path, O_RDONLY | O_CLOEXEC)) == -1) 1616 return (NULL); 1617 if (read(fd, &hdr, sizeof hdr) != sizeof hdr || 1618 hdr.magic != ELFHINTS_MAGIC || 1619 hdr.version != 1) { 1620 close(fd); 1621 return (NULL); 1622 } 1623 p = xmalloc(hdr.dirlistlen + 1); 1624 if (lseek(fd, hdr.strtab + hdr.dirlist, SEEK_SET) == -1 || 1625 read(fd, p, hdr.dirlistlen + 1) != 1626 (ssize_t)hdr.dirlistlen + 1) { 1627 free(p); 1628 close(fd); 1629 return (NULL); 1630 } 1631 hints = p; 1632 close(fd); 1633 } 1634 1635 /* 1636 * If caller agreed to receive list which includes the default 1637 * paths, we are done. Otherwise, if we still did not 1638 * calculated filtered result, do it now. 1639 */ 1640 if (!nostdlib) 1641 return (hints[0] != '\0' ? hints : NULL); 1642 if (filtered_path != NULL) 1643 goto filt_ret; 1644 1645 /* 1646 * Obtain the list of all configured search paths, and the 1647 * list of the default paths. 1648 * 1649 * First estimate the size of the results. 1650 */ 1651 smeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 1652 smeta.dls_cnt = 0; 1653 hmeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 1654 hmeta.dls_cnt = 0; 1655 1656 sargs.request = RTLD_DI_SERINFOSIZE; 1657 sargs.serinfo = &smeta; 1658 hargs.request = RTLD_DI_SERINFOSIZE; 1659 hargs.serinfo = &hmeta; 1660 1661 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &sargs); 1662 path_enumerate(p, fill_search_info, &hargs); 1663 1664 SLPinfo = xmalloc(smeta.dls_size); 1665 hintinfo = xmalloc(hmeta.dls_size); 1666 1667 /* 1668 * Next fetch both sets of paths. 1669 */ 1670 sargs.request = RTLD_DI_SERINFO; 1671 sargs.serinfo = SLPinfo; 1672 sargs.serpath = &SLPinfo->dls_serpath[0]; 1673 sargs.strspace = (char *)&SLPinfo->dls_serpath[smeta.dls_cnt]; 1674 1675 hargs.request = RTLD_DI_SERINFO; 1676 hargs.serinfo = hintinfo; 1677 hargs.serpath = &hintinfo->dls_serpath[0]; 1678 hargs.strspace = (char *)&hintinfo->dls_serpath[hmeta.dls_cnt]; 1679 1680 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &sargs); 1681 path_enumerate(p, fill_search_info, &hargs); 1682 1683 /* 1684 * Now calculate the difference between two sets, by excluding 1685 * standard paths from the full set. 1686 */ 1687 fndx = 0; 1688 fcount = 0; 1689 filtered_path = xmalloc(hdr.dirlistlen + 1); 1690 hintpath = &hintinfo->dls_serpath[0]; 1691 for (hintndx = 0; hintndx < hmeta.dls_cnt; hintndx++, hintpath++) { 1692 skip = false; 1693 SLPpath = &SLPinfo->dls_serpath[0]; 1694 /* 1695 * Check each standard path against current. 1696 */ 1697 for (SLPndx = 0; SLPndx < smeta.dls_cnt; SLPndx++, SLPpath++) { 1698 /* matched, skip the path */ 1699 if (!strcmp(hintpath->dls_name, SLPpath->dls_name)) { 1700 skip = true; 1701 break; 1702 } 1703 } 1704 if (skip) 1705 continue; 1706 /* 1707 * Not matched against any standard path, add the path 1708 * to result. Separate consequtive paths with ':'. 1709 */ 1710 if (fcount > 0) { 1711 filtered_path[fndx] = ':'; 1712 fndx++; 1713 } 1714 fcount++; 1715 flen = strlen(hintpath->dls_name); 1716 strncpy((filtered_path + fndx), hintpath->dls_name, flen); 1717 fndx += flen; 1718 } 1719 filtered_path[fndx] = '\0'; 1720 1721 free(SLPinfo); 1722 free(hintinfo); 1723 1724filt_ret: 1725 return (filtered_path[0] != '\0' ? filtered_path : NULL); 1726} 1727 1728static void 1729init_dag(Obj_Entry *root) 1730{ 1731 const Needed_Entry *needed; 1732 const Objlist_Entry *elm; 1733 DoneList donelist; 1734 1735 if (root->dag_inited) 1736 return; 1737 donelist_init(&donelist); 1738 1739 /* Root object belongs to own DAG. */ 1740 objlist_push_tail(&root->dldags, root); 1741 objlist_push_tail(&root->dagmembers, root); 1742 donelist_check(&donelist, root); 1743 1744 /* 1745 * Add dependencies of root object to DAG in breadth order 1746 * by exploiting the fact that each new object get added 1747 * to the tail of the dagmembers list. 1748 */ 1749 STAILQ_FOREACH(elm, &root->dagmembers, link) { 1750 for (needed = elm->obj->needed; needed != NULL; needed = needed->next) { 1751 if (needed->obj == NULL || donelist_check(&donelist, needed->obj)) 1752 continue; 1753 objlist_push_tail(&needed->obj->dldags, root); 1754 objlist_push_tail(&root->dagmembers, needed->obj); 1755 } 1756 } 1757 root->dag_inited = true; 1758} 1759 1760static void 1761process_nodelete(Obj_Entry *root) 1762{ 1763 const Objlist_Entry *elm; 1764 1765 /* 1766 * Walk over object DAG and process every dependent object that 1767 * is marked as DF_1_NODELETE. They need to grow their own DAG, 1768 * which then should have its reference upped separately. 1769 */ 1770 STAILQ_FOREACH(elm, &root->dagmembers, link) { 1771 if (elm->obj != NULL && elm->obj->z_nodelete && 1772 !elm->obj->ref_nodel) { 1773 dbg("obj %s nodelete", elm->obj->path); 1774 init_dag(elm->obj); 1775 ref_dag(elm->obj); 1776 elm->obj->ref_nodel = true; 1777 } 1778 } 1779} 1780/* 1781 * Initialize the dynamic linker. The argument is the address at which 1782 * the dynamic linker has been mapped into memory. The primary task of 1783 * this function is to relocate the dynamic linker. 1784 */ 1785static void 1786init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info) 1787{ 1788 Obj_Entry objtmp; /* Temporary rtld object */ 1789 const Elf_Dyn *dyn_rpath; 1790 const Elf_Dyn *dyn_soname; 1791 const Elf_Dyn *dyn_runpath; 1792 1793 /* 1794 * Conjure up an Obj_Entry structure for the dynamic linker. 1795 * 1796 * The "path" member can't be initialized yet because string constants 1797 * cannot yet be accessed. Below we will set it correctly. 1798 */ 1799 memset(&objtmp, 0, sizeof(objtmp)); 1800 objtmp.path = NULL; 1801 objtmp.rtld = true; 1802 objtmp.mapbase = mapbase; 1803#ifdef PIC 1804 objtmp.relocbase = mapbase; 1805#endif 1806 if (RTLD_IS_DYNAMIC()) { 1807 objtmp.dynamic = rtld_dynamic(&objtmp); 1808 digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname, &dyn_runpath); 1809 assert(objtmp.needed == NULL); 1810#if !defined(__mips__) 1811 /* MIPS has a bogus DT_TEXTREL. */ 1812 assert(!objtmp.textrel); 1813#endif 1814 1815 /* 1816 * Temporarily put the dynamic linker entry into the object list, so 1817 * that symbols can be found. 1818 */ 1819 1820 relocate_objects(&objtmp, true, &objtmp, 0, NULL); 1821 } 1822 1823 /* Initialize the object list. */ 1824 obj_tail = &obj_list; 1825 1826 /* Now that non-local variables can be accesses, copy out obj_rtld. */ 1827 memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld)); 1828 1829 /* The page size is required by the dynamic memory allocator. */ 1830 init_pagesizes(aux_info); 1831 1832 if (aux_info[AT_OSRELDATE] != NULL) 1833 osreldate = aux_info[AT_OSRELDATE]->a_un.a_val; 1834 1835 digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname, dyn_runpath); 1836 1837 /* Replace the path with a dynamically allocated copy. */ 1838 obj_rtld.path = xstrdup(PATH_RTLD); 1839 1840 r_debug.r_brk = r_debug_state; 1841 r_debug.r_state = RT_CONSISTENT; 1842} 1843 1844/* 1845 * Retrieve the array of supported page sizes. The kernel provides the page 1846 * sizes in increasing order. 1847 */ 1848static void 1849init_pagesizes(Elf_Auxinfo **aux_info) 1850{ 1851 static size_t psa[MAXPAGESIZES]; 1852 int mib[2]; 1853 size_t len, size; 1854 1855 if (aux_info[AT_PAGESIZES] != NULL && aux_info[AT_PAGESIZESLEN] != 1856 NULL) { 1857 size = aux_info[AT_PAGESIZESLEN]->a_un.a_val; 1858 pagesizes = aux_info[AT_PAGESIZES]->a_un.a_ptr; 1859 } else { 1860 len = 2; 1861 if (sysctlnametomib("hw.pagesizes", mib, &len) == 0) 1862 size = sizeof(psa); 1863 else { 1864 /* As a fallback, retrieve the base page size. */ 1865 size = sizeof(psa[0]); 1866 if (aux_info[AT_PAGESZ] != NULL) { 1867 psa[0] = aux_info[AT_PAGESZ]->a_un.a_val; 1868 goto psa_filled; 1869 } else { 1870 mib[0] = CTL_HW; 1871 mib[1] = HW_PAGESIZE; 1872 len = 2; 1873 } 1874 } 1875 if (sysctl(mib, len, psa, &size, NULL, 0) == -1) { 1876 _rtld_error("sysctl for hw.pagesize(s) failed"); 1877 die(); 1878 } 1879psa_filled: 1880 pagesizes = psa; 1881 } 1882 npagesizes = size / sizeof(pagesizes[0]); 1883 /* Discard any invalid entries at the end of the array. */ 1884 while (npagesizes > 0 && pagesizes[npagesizes - 1] == 0) 1885 npagesizes--; 1886} 1887 1888/* 1889 * Add the init functions from a needed object list (and its recursive 1890 * needed objects) to "list". This is not used directly; it is a helper 1891 * function for initlist_add_objects(). The write lock must be held 1892 * when this function is called. 1893 */ 1894static void 1895initlist_add_neededs(Needed_Entry *needed, Objlist *list) 1896{ 1897 /* Recursively process the successor needed objects. */ 1898 if (needed->next != NULL) 1899 initlist_add_neededs(needed->next, list); 1900 1901 /* Process the current needed object. */ 1902 if (needed->obj != NULL) 1903 initlist_add_objects(needed->obj, &needed->obj->next, list); 1904} 1905 1906/* 1907 * Scan all of the DAGs rooted in the range of objects from "obj" to 1908 * "tail" and add their init functions to "list". This recurses over 1909 * the DAGs and ensure the proper init ordering such that each object's 1910 * needed libraries are initialized before the object itself. At the 1911 * same time, this function adds the objects to the global finalization 1912 * list "list_fini" in the opposite order. The write lock must be 1913 * held when this function is called. 1914 */ 1915static void 1916initlist_add_objects(Obj_Entry *obj, Obj_Entry **tail, Objlist *list) 1917{ 1918 1919 if (obj->init_scanned || obj->init_done) 1920 return; 1921 obj->init_scanned = true; 1922 1923 /* Recursively process the successor objects. */ 1924 if (&obj->next != tail) 1925 initlist_add_objects(obj->next, tail, list); 1926 1927 /* Recursively process the needed objects. */ 1928 if (obj->needed != NULL) 1929 initlist_add_neededs(obj->needed, list); 1930 if (obj->needed_filtees != NULL) 1931 initlist_add_neededs(obj->needed_filtees, list); 1932 if (obj->needed_aux_filtees != NULL) 1933 initlist_add_neededs(obj->needed_aux_filtees, list); 1934 1935 /* Add the object to the init list. */ 1936 if (obj->preinit_array != (Elf_Addr)NULL || obj->init != (Elf_Addr)NULL || 1937 obj->init_array != (Elf_Addr)NULL) 1938 objlist_push_tail(list, obj); 1939 1940 /* Add the object to the global fini list in the reverse order. */ 1941 if ((obj->fini != (Elf_Addr)NULL || obj->fini_array != (Elf_Addr)NULL) 1942 && !obj->on_fini_list) { 1943 objlist_push_head(&list_fini, obj); 1944 obj->on_fini_list = true; 1945 } 1946} 1947 1948#ifndef FPTR_TARGET 1949#define FPTR_TARGET(f) ((Elf_Addr) (f)) 1950#endif 1951 1952static void 1953free_needed_filtees(Needed_Entry *n) 1954{ 1955 Needed_Entry *needed, *needed1; 1956 1957 for (needed = n; needed != NULL; needed = needed->next) { 1958 if (needed->obj != NULL) { 1959 dlclose(needed->obj); 1960 needed->obj = NULL; 1961 } 1962 } 1963 for (needed = n; needed != NULL; needed = needed1) { 1964 needed1 = needed->next; 1965 free(needed); 1966 } 1967} 1968 1969static void 1970unload_filtees(Obj_Entry *obj) 1971{ 1972 1973 free_needed_filtees(obj->needed_filtees); 1974 obj->needed_filtees = NULL; 1975 free_needed_filtees(obj->needed_aux_filtees); 1976 obj->needed_aux_filtees = NULL; 1977 obj->filtees_loaded = false; 1978} 1979 1980static void 1981load_filtee1(Obj_Entry *obj, Needed_Entry *needed, int flags, 1982 RtldLockState *lockstate) 1983{ 1984 1985 for (; needed != NULL; needed = needed->next) { 1986 needed->obj = dlopen_object(obj->strtab + needed->name, -1, obj, 1987 flags, ((ld_loadfltr || obj->z_loadfltr) ? RTLD_NOW : RTLD_LAZY) | 1988 RTLD_LOCAL, lockstate); 1989 } 1990} 1991 1992static void 1993load_filtees(Obj_Entry *obj, int flags, RtldLockState *lockstate) 1994{ 1995 1996 lock_restart_for_upgrade(lockstate); 1997 if (!obj->filtees_loaded) { 1998 load_filtee1(obj, obj->needed_filtees, flags, lockstate); 1999 load_filtee1(obj, obj->needed_aux_filtees, flags, lockstate); 2000 obj->filtees_loaded = true; 2001 } 2002} 2003 2004static int 2005process_needed(Obj_Entry *obj, Needed_Entry *needed, int flags) 2006{ 2007 Obj_Entry *obj1; 2008 2009 for (; needed != NULL; needed = needed->next) { 2010 obj1 = needed->obj = load_object(obj->strtab + needed->name, -1, obj, 2011 flags & ~RTLD_LO_NOLOAD); 2012 if (obj1 == NULL && !ld_tracing && (flags & RTLD_LO_FILTEES) == 0) 2013 return (-1); 2014 } 2015 return (0); 2016} 2017 2018/* 2019 * Given a shared object, traverse its list of needed objects, and load 2020 * each of them. Returns 0 on success. Generates an error message and 2021 * returns -1 on failure. 2022 */ 2023static int 2024load_needed_objects(Obj_Entry *first, int flags) 2025{ 2026 Obj_Entry *obj; 2027 2028 for (obj = first; obj != NULL; obj = obj->next) { 2029 if (process_needed(obj, obj->needed, flags) == -1) 2030 return (-1); 2031 } 2032 return (0); 2033} 2034 2035static int 2036load_preload_objects(void) 2037{ 2038 char *p = ld_preload; 2039 Obj_Entry *obj; 2040 static const char delim[] = " \t:;"; 2041 2042 if (p == NULL) 2043 return 0; 2044 2045 p += strspn(p, delim); 2046 while (*p != '\0') { 2047 size_t len = strcspn(p, delim); 2048 char savech; 2049 2050 savech = p[len]; 2051 p[len] = '\0'; 2052 obj = load_object(p, -1, NULL, 0); 2053 if (obj == NULL) 2054 return -1; /* XXX - cleanup */ 2055 obj->z_interpose = true; 2056 p[len] = savech; 2057 p += len; 2058 p += strspn(p, delim); 2059 } 2060 LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL); 2061 return 0; 2062} 2063 2064static const char * 2065printable_path(const char *path) 2066{ 2067 2068 return (path == NULL ? "<unknown>" : path); 2069} 2070 2071/* 2072 * Load a shared object into memory, if it is not already loaded. The 2073 * object may be specified by name or by user-supplied file descriptor 2074 * fd_u. In the later case, the fd_u descriptor is not closed, but its 2075 * duplicate is. 2076 * 2077 * Returns a pointer to the Obj_Entry for the object. Returns NULL 2078 * on failure. 2079 */ 2080static Obj_Entry * 2081load_object(const char *name, int fd_u, const Obj_Entry *refobj, int flags) 2082{ 2083 Obj_Entry *obj; 2084 int fd; 2085 struct stat sb; 2086 char *path; 2087 2088 if (name != NULL) { 2089 for (obj = obj_list->next; obj != NULL; obj = obj->next) { 2090 if (object_match_name(obj, name)) 2091 return (obj); 2092 } 2093 2094 path = find_library(name, refobj); 2095 if (path == NULL) 2096 return (NULL); 2097 } else 2098 path = NULL; 2099 2100 /* 2101 * If we didn't find a match by pathname, or the name is not 2102 * supplied, open the file and check again by device and inode. 2103 * This avoids false mismatches caused by multiple links or ".." 2104 * in pathnames. 2105 * 2106 * To avoid a race, we open the file and use fstat() rather than 2107 * using stat(). 2108 */ 2109 fd = -1; 2110 if (fd_u == -1) { 2111 if ((fd = open(path, O_RDONLY | O_CLOEXEC)) == -1) { 2112 _rtld_error("Cannot open \"%s\"", path); 2113 free(path); 2114 return (NULL); 2115 } 2116 } else { 2117 fd = fcntl(fd_u, F_DUPFD_CLOEXEC, 0); 2118 if (fd == -1) { 2119 _rtld_error("Cannot dup fd"); 2120 free(path); 2121 return (NULL); 2122 } 2123 } 2124 if (fstat(fd, &sb) == -1) { 2125 _rtld_error("Cannot fstat \"%s\"", printable_path(path)); 2126 close(fd); 2127 free(path); 2128 return NULL; 2129 } 2130 for (obj = obj_list->next; obj != NULL; obj = obj->next) 2131 if (obj->ino == sb.st_ino && obj->dev == sb.st_dev) 2132 break; 2133 if (obj != NULL && name != NULL) { 2134 object_add_name(obj, name); 2135 free(path); 2136 close(fd); 2137 return obj; 2138 } 2139 if (flags & RTLD_LO_NOLOAD) { 2140 free(path); 2141 close(fd); 2142 return (NULL); 2143 } 2144 2145 /* First use of this object, so we must map it in */ 2146 obj = do_load_object(fd, name, path, &sb, flags); 2147 if (obj == NULL) 2148 free(path); 2149 close(fd); 2150 2151 return obj; 2152} 2153 2154static Obj_Entry * 2155do_load_object(int fd, const char *name, char *path, struct stat *sbp, 2156 int flags) 2157{ 2158 Obj_Entry *obj; 2159 struct statfs fs; 2160 2161 /* 2162 * but first, make sure that environment variables haven't been 2163 * used to circumvent the noexec flag on a filesystem. 2164 */ 2165 if (dangerous_ld_env) { 2166 if (fstatfs(fd, &fs) != 0) { 2167 _rtld_error("Cannot fstatfs \"%s\"", printable_path(path)); 2168 return NULL; 2169 } 2170 if (fs.f_flags & MNT_NOEXEC) { 2171 _rtld_error("Cannot execute objects on %s\n", fs.f_mntonname); 2172 return NULL; 2173 } 2174 } 2175 dbg("loading \"%s\"", printable_path(path)); 2176 obj = map_object(fd, printable_path(path), sbp); 2177 if (obj == NULL) 2178 return NULL; 2179 2180 /* 2181 * If DT_SONAME is present in the object, digest_dynamic2 already 2182 * added it to the object names. 2183 */ 2184 if (name != NULL) 2185 object_add_name(obj, name); 2186 obj->path = path; 2187 digest_dynamic(obj, 0); 2188 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", obj->path, 2189 obj->valid_hash_sysv, obj->valid_hash_gnu, obj->dynsymcount); 2190 if (obj->z_noopen && (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) == 2191 RTLD_LO_DLOPEN) { 2192 dbg("refusing to load non-loadable \"%s\"", obj->path); 2193 _rtld_error("Cannot dlopen non-loadable %s", obj->path); 2194 munmap(obj->mapbase, obj->mapsize); 2195 obj_free(obj); 2196 return (NULL); 2197 } 2198 2199 obj->dlopened = (flags & RTLD_LO_DLOPEN) != 0; 2200 *obj_tail = obj; 2201 obj_tail = &obj->next; 2202 obj_count++; 2203 obj_loads++; 2204 linkmap_add(obj); /* for GDB & dlinfo() */ 2205 max_stack_flags |= obj->stack_flags; 2206 2207 dbg(" %p .. %p: %s", obj->mapbase, 2208 obj->mapbase + obj->mapsize - 1, obj->path); 2209 if (obj->textrel) 2210 dbg(" WARNING: %s has impure text", obj->path); 2211 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 2212 obj->path); 2213 2214 return obj; 2215} 2216 2217static Obj_Entry * 2218obj_from_addr(const void *addr) 2219{ 2220 Obj_Entry *obj; 2221 2222 for (obj = obj_list; obj != NULL; obj = obj->next) { 2223 if (addr < (void *) obj->mapbase) 2224 continue; 2225 if (addr < (void *) (obj->mapbase + obj->mapsize)) 2226 return obj; 2227 } 2228 return NULL; 2229} 2230 2231static void 2232preinit_main(void) 2233{ 2234 Elf_Addr *preinit_addr; 2235 int index; 2236 2237 preinit_addr = (Elf_Addr *)obj_main->preinit_array; 2238 if (preinit_addr == NULL) 2239 return; 2240 2241 for (index = 0; index < obj_main->preinit_array_num; index++) { 2242 if (preinit_addr[index] != 0 && preinit_addr[index] != 1) { 2243 dbg("calling preinit function for %s at %p", obj_main->path, 2244 (void *)preinit_addr[index]); 2245 LD_UTRACE(UTRACE_INIT_CALL, obj_main, (void *)preinit_addr[index], 2246 0, 0, obj_main->path); 2247 call_init_pointer(obj_main, preinit_addr[index]); 2248 } 2249 } 2250} 2251 2252/* 2253 * Call the finalization functions for each of the objects in "list" 2254 * belonging to the DAG of "root" and referenced once. If NULL "root" 2255 * is specified, every finalization function will be called regardless 2256 * of the reference count and the list elements won't be freed. All of 2257 * the objects are expected to have non-NULL fini functions. 2258 */ 2259static void 2260objlist_call_fini(Objlist *list, Obj_Entry *root, RtldLockState *lockstate) 2261{ 2262 Objlist_Entry *elm; 2263 char *saved_msg; 2264 Elf_Addr *fini_addr; 2265 int index; 2266 2267 assert(root == NULL || root->refcount == 1); 2268 2269 /* 2270 * Preserve the current error message since a fini function might 2271 * call into the dynamic linker and overwrite it. 2272 */ 2273 saved_msg = errmsg_save(); 2274 do { 2275 STAILQ_FOREACH(elm, list, link) { 2276 if (root != NULL && (elm->obj->refcount != 1 || 2277 objlist_find(&root->dagmembers, elm->obj) == NULL)) 2278 continue; 2279 /* Remove object from fini list to prevent recursive invocation. */ 2280 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 2281 /* 2282 * XXX: If a dlopen() call references an object while the 2283 * fini function is in progress, we might end up trying to 2284 * unload the referenced object in dlclose() or the object 2285 * won't be unloaded although its fini function has been 2286 * called. 2287 */ 2288 lock_release(rtld_bind_lock, lockstate); 2289 2290 /* 2291 * It is legal to have both DT_FINI and DT_FINI_ARRAY defined. 2292 * When this happens, DT_FINI_ARRAY is processed first. 2293 */ 2294 fini_addr = (Elf_Addr *)elm->obj->fini_array; 2295 if (fini_addr != NULL && elm->obj->fini_array_num > 0) { 2296 for (index = elm->obj->fini_array_num - 1; index >= 0; 2297 index--) { 2298 if (fini_addr[index] != 0 && fini_addr[index] != 1) { 2299 dbg("calling fini function for %s at %p", 2300 elm->obj->path, (void *)fini_addr[index]); 2301 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, 2302 (void *)fini_addr[index], 0, 0, elm->obj->path); 2303 call_initfini_pointer(elm->obj, fini_addr[index]); 2304 } 2305 } 2306 } 2307 if (elm->obj->fini != (Elf_Addr)NULL) { 2308 dbg("calling fini function for %s at %p", elm->obj->path, 2309 (void *)elm->obj->fini); 2310 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, (void *)elm->obj->fini, 2311 0, 0, elm->obj->path); 2312 call_initfini_pointer(elm->obj, elm->obj->fini); 2313 } 2314 wlock_acquire(rtld_bind_lock, lockstate); 2315 /* No need to free anything if process is going down. */ 2316 if (root != NULL) 2317 free(elm); 2318 /* 2319 * We must restart the list traversal after every fini call 2320 * because a dlclose() call from the fini function or from 2321 * another thread might have modified the reference counts. 2322 */ 2323 break; 2324 } 2325 } while (elm != NULL); 2326 errmsg_restore(saved_msg); 2327} 2328 2329/* 2330 * Call the initialization functions for each of the objects in 2331 * "list". All of the objects are expected to have non-NULL init 2332 * functions. 2333 */ 2334static void 2335objlist_call_init(Objlist *list, RtldLockState *lockstate) 2336{ 2337 Objlist_Entry *elm; 2338 Obj_Entry *obj; 2339 char *saved_msg; 2340 Elf_Addr *init_addr; 2341 int index; 2342 2343 /* 2344 * Clean init_scanned flag so that objects can be rechecked and 2345 * possibly initialized earlier if any of vectors called below 2346 * cause the change by using dlopen. 2347 */ 2348 for (obj = obj_list; obj != NULL; obj = obj->next) 2349 obj->init_scanned = false; 2350 2351 /* 2352 * Preserve the current error message since an init function might 2353 * call into the dynamic linker and overwrite it. 2354 */ 2355 saved_msg = errmsg_save(); 2356 STAILQ_FOREACH(elm, list, link) { 2357 if (elm->obj->init_done) /* Initialized early. */ 2358 continue; 2359 /* 2360 * Race: other thread might try to use this object before current 2361 * one completes the initilization. Not much can be done here 2362 * without better locking. 2363 */ 2364 elm->obj->init_done = true; 2365 lock_release(rtld_bind_lock, lockstate); 2366 2367 /* 2368 * It is legal to have both DT_INIT and DT_INIT_ARRAY defined. 2369 * When this happens, DT_INIT is processed first. 2370 */ 2371 if (elm->obj->init != (Elf_Addr)NULL) { 2372 dbg("calling init function for %s at %p", elm->obj->path, 2373 (void *)elm->obj->init); 2374 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, (void *)elm->obj->init, 2375 0, 0, elm->obj->path); 2376 call_initfini_pointer(elm->obj, elm->obj->init); 2377 } 2378 init_addr = (Elf_Addr *)elm->obj->init_array; 2379 if (init_addr != NULL) { 2380 for (index = 0; index < elm->obj->init_array_num; index++) { 2381 if (init_addr[index] != 0 && init_addr[index] != 1) { 2382 dbg("calling init function for %s at %p", elm->obj->path, 2383 (void *)init_addr[index]); 2384 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, 2385 (void *)init_addr[index], 0, 0, elm->obj->path); 2386 call_init_pointer(elm->obj, init_addr[index]); 2387 } 2388 } 2389 } 2390 wlock_acquire(rtld_bind_lock, lockstate); 2391 } 2392 errmsg_restore(saved_msg); 2393} 2394 2395static void 2396objlist_clear(Objlist *list) 2397{ 2398 Objlist_Entry *elm; 2399 2400 while (!STAILQ_EMPTY(list)) { 2401 elm = STAILQ_FIRST(list); 2402 STAILQ_REMOVE_HEAD(list, link); 2403 free(elm); 2404 } 2405} 2406 2407static Objlist_Entry * 2408objlist_find(Objlist *list, const Obj_Entry *obj) 2409{ 2410 Objlist_Entry *elm; 2411 2412 STAILQ_FOREACH(elm, list, link) 2413 if (elm->obj == obj) 2414 return elm; 2415 return NULL; 2416} 2417 2418static void 2419objlist_init(Objlist *list) 2420{ 2421 STAILQ_INIT(list); 2422} 2423 2424static void 2425objlist_push_head(Objlist *list, Obj_Entry *obj) 2426{ 2427 Objlist_Entry *elm; 2428 2429 elm = NEW(Objlist_Entry); 2430 elm->obj = obj; 2431 STAILQ_INSERT_HEAD(list, elm, link); 2432} 2433 2434static void 2435objlist_push_tail(Objlist *list, Obj_Entry *obj) 2436{ 2437 Objlist_Entry *elm; 2438 2439 elm = NEW(Objlist_Entry); 2440 elm->obj = obj; 2441 STAILQ_INSERT_TAIL(list, elm, link); 2442} 2443 2444static void 2445objlist_put_after(Objlist *list, Obj_Entry *listobj, Obj_Entry *obj) 2446{ 2447 Objlist_Entry *elm, *listelm; 2448 2449 STAILQ_FOREACH(listelm, list, link) { 2450 if (listelm->obj == listobj) 2451 break; 2452 } 2453 elm = NEW(Objlist_Entry); 2454 elm->obj = obj; 2455 if (listelm != NULL) 2456 STAILQ_INSERT_AFTER(list, listelm, elm, link); 2457 else 2458 STAILQ_INSERT_TAIL(list, elm, link); 2459} 2460 2461static void 2462objlist_remove(Objlist *list, Obj_Entry *obj) 2463{ 2464 Objlist_Entry *elm; 2465 2466 if ((elm = objlist_find(list, obj)) != NULL) { 2467 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link); 2468 free(elm); 2469 } 2470} 2471 2472/* 2473 * Relocate dag rooted in the specified object. 2474 * Returns 0 on success, or -1 on failure. 2475 */ 2476 2477static int 2478relocate_object_dag(Obj_Entry *root, bool bind_now, Obj_Entry *rtldobj, 2479 int flags, RtldLockState *lockstate) 2480{ 2481 Objlist_Entry *elm; 2482 int error; 2483 2484 error = 0; 2485 STAILQ_FOREACH(elm, &root->dagmembers, link) { 2486 error = relocate_object(elm->obj, bind_now, rtldobj, flags, 2487 lockstate); 2488 if (error == -1) 2489 break; 2490 } 2491 return (error); 2492} 2493 2494/* 2495 * Relocate single object. 2496 * Returns 0 on success, or -1 on failure. 2497 */ 2498static int 2499relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj, 2500 int flags, RtldLockState *lockstate) 2501{ 2502 2503 if (obj->relocated) 2504 return (0); 2505 obj->relocated = true; 2506 if (obj != rtldobj) 2507 dbg("relocating \"%s\"", obj->path); 2508 2509 if (obj->symtab == NULL || obj->strtab == NULL || 2510 !(obj->valid_hash_sysv || obj->valid_hash_gnu)) { 2511 _rtld_error("%s: Shared object has no run-time symbol table", 2512 obj->path); 2513 return (-1); 2514 } 2515 2516 if (obj->textrel) { 2517 /* There are relocations to the write-protected text segment. */ 2518 if (mprotect(obj->mapbase, obj->textsize, 2519 PROT_READ|PROT_WRITE|PROT_EXEC) == -1) { 2520 _rtld_error("%s: Cannot write-enable text segment: %s", 2521 obj->path, rtld_strerror(errno)); 2522 return (-1); 2523 } 2524 } 2525 2526 /* Process the non-PLT non-IFUNC relocations. */ 2527 if (reloc_non_plt(obj, rtldobj, flags, lockstate)) 2528 return (-1); 2529 2530 if (obj->textrel) { /* Re-protected the text segment. */ 2531 if (mprotect(obj->mapbase, obj->textsize, 2532 PROT_READ|PROT_EXEC) == -1) { 2533 _rtld_error("%s: Cannot write-protect text segment: %s", 2534 obj->path, rtld_strerror(errno)); 2535 return (-1); 2536 } 2537 } 2538 2539 /* Set the special PLT or GOT entries. */ 2540 init_pltgot(obj); 2541 2542 /* Process the PLT relocations. */ 2543 if (reloc_plt(obj) == -1) 2544 return (-1); 2545 /* Relocate the jump slots if we are doing immediate binding. */ 2546 if (obj->bind_now || bind_now) 2547 if (reloc_jmpslots(obj, flags, lockstate) == -1) 2548 return (-1); 2549 2550 /* 2551 * Process the non-PLT IFUNC relocations. The relocations are 2552 * processed in two phases, because IFUNC resolvers may 2553 * reference other symbols, which must be readily processed 2554 * before resolvers are called. 2555 */ 2556 if (obj->non_plt_gnu_ifunc && 2557 reloc_non_plt(obj, rtldobj, flags | SYMLOOK_IFUNC, lockstate)) 2558 return (-1); 2559 2560 if (obj->relro_size > 0) { 2561 if (mprotect(obj->relro_page, obj->relro_size, 2562 PROT_READ) == -1) { 2563 _rtld_error("%s: Cannot enforce relro protection: %s", 2564 obj->path, rtld_strerror(errno)); 2565 return (-1); 2566 } 2567 } 2568 2569 /* 2570 * Set up the magic number and version in the Obj_Entry. These 2571 * were checked in the crt1.o from the original ElfKit, so we 2572 * set them for backward compatibility. 2573 */ 2574 obj->magic = RTLD_MAGIC; 2575 obj->version = RTLD_VERSION; 2576 2577 return (0); 2578} 2579 2580/* 2581 * Relocate newly-loaded shared objects. The argument is a pointer to 2582 * the Obj_Entry for the first such object. All objects from the first 2583 * to the end of the list of objects are relocated. Returns 0 on success, 2584 * or -1 on failure. 2585 */ 2586static int 2587relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj, 2588 int flags, RtldLockState *lockstate) 2589{ 2590 Obj_Entry *obj; 2591 int error; 2592 2593 for (error = 0, obj = first; obj != NULL; obj = obj->next) { 2594 error = relocate_object(obj, bind_now, rtldobj, flags, 2595 lockstate); 2596 if (error == -1) 2597 break; 2598 } 2599 return (error); 2600} 2601 2602/* 2603 * The handling of R_MACHINE_IRELATIVE relocations and jumpslots 2604 * referencing STT_GNU_IFUNC symbols is postponed till the other 2605 * relocations are done. The indirect functions specified as 2606 * ifunc are allowed to call other symbols, so we need to have 2607 * objects relocated before asking for resolution from indirects. 2608 * 2609 * The R_MACHINE_IRELATIVE slots are resolved in greedy fashion, 2610 * instead of the usual lazy handling of PLT slots. It is 2611 * consistent with how GNU does it. 2612 */ 2613static int 2614resolve_object_ifunc(Obj_Entry *obj, bool bind_now, int flags, 2615 RtldLockState *lockstate) 2616{ 2617 if (obj->irelative && reloc_iresolve(obj, lockstate) == -1) 2618 return (-1); 2619 if ((obj->bind_now || bind_now) && obj->gnu_ifunc && 2620 reloc_gnu_ifunc(obj, flags, lockstate) == -1) 2621 return (-1); 2622 return (0); 2623} 2624 2625static int 2626resolve_objects_ifunc(Obj_Entry *first, bool bind_now, int flags, 2627 RtldLockState *lockstate) 2628{ 2629 Obj_Entry *obj; 2630 2631 for (obj = first; obj != NULL; obj = obj->next) { 2632 if (resolve_object_ifunc(obj, bind_now, flags, lockstate) == -1) 2633 return (-1); 2634 } 2635 return (0); 2636} 2637 2638static int 2639initlist_objects_ifunc(Objlist *list, bool bind_now, int flags, 2640 RtldLockState *lockstate) 2641{ 2642 Objlist_Entry *elm; 2643 2644 STAILQ_FOREACH(elm, list, link) { 2645 if (resolve_object_ifunc(elm->obj, bind_now, flags, 2646 lockstate) == -1) 2647 return (-1); 2648 } 2649 return (0); 2650} 2651 2652/* 2653 * Cleanup procedure. It will be called (by the atexit mechanism) just 2654 * before the process exits. 2655 */ 2656static void 2657rtld_exit(void) 2658{ 2659 RtldLockState lockstate; 2660 2661 wlock_acquire(rtld_bind_lock, &lockstate); 2662 dbg("rtld_exit()"); 2663 objlist_call_fini(&list_fini, NULL, &lockstate); 2664 /* No need to remove the items from the list, since we are exiting. */ 2665 if (!libmap_disable) 2666 lm_fini(); 2667 lock_release(rtld_bind_lock, &lockstate); 2668} 2669 2670/* 2671 * Iterate over a search path, translate each element, and invoke the 2672 * callback on the result. 2673 */ 2674static void * 2675path_enumerate(const char *path, path_enum_proc callback, void *arg) 2676{ 2677 const char *trans; 2678 if (path == NULL) 2679 return (NULL); 2680 2681 path += strspn(path, ":;"); 2682 while (*path != '\0') { 2683 size_t len; 2684 char *res; 2685 2686 len = strcspn(path, ":;"); 2687 trans = lm_findn(NULL, path, len); 2688 if (trans) 2689 res = callback(trans, strlen(trans), arg); 2690 else 2691 res = callback(path, len, arg); 2692 2693 if (res != NULL) 2694 return (res); 2695 2696 path += len; 2697 path += strspn(path, ":;"); 2698 } 2699 2700 return (NULL); 2701} 2702 2703struct try_library_args { 2704 const char *name; 2705 size_t namelen; 2706 char *buffer; 2707 size_t buflen; 2708}; 2709 2710static void * 2711try_library_path(const char *dir, size_t dirlen, void *param) 2712{ 2713 struct try_library_args *arg; 2714 2715 arg = param; 2716 if (*dir == '/' || trust) { 2717 char *pathname; 2718 2719 if (dirlen + 1 + arg->namelen + 1 > arg->buflen) 2720 return (NULL); 2721 2722 pathname = arg->buffer; 2723 strncpy(pathname, dir, dirlen); 2724 pathname[dirlen] = '/'; 2725 strcpy(pathname + dirlen + 1, arg->name); 2726 2727 dbg(" Trying \"%s\"", pathname); 2728 if (access(pathname, F_OK) == 0) { /* We found it */ 2729 pathname = xmalloc(dirlen + 1 + arg->namelen + 1); 2730 strcpy(pathname, arg->buffer); 2731 return (pathname); 2732 } 2733 } 2734 return (NULL); 2735} 2736 2737static char * 2738search_library_path(const char *name, const char *path) 2739{ 2740 char *p; 2741 struct try_library_args arg; 2742 2743 if (path == NULL) 2744 return NULL; 2745 2746 arg.name = name; 2747 arg.namelen = strlen(name); 2748 arg.buffer = xmalloc(PATH_MAX); 2749 arg.buflen = PATH_MAX; 2750 2751 p = path_enumerate(path, try_library_path, &arg); 2752 2753 free(arg.buffer); 2754 2755 return (p); 2756} 2757 2758int 2759dlclose(void *handle) 2760{ 2761 Obj_Entry *root; 2762 RtldLockState lockstate; 2763 2764 wlock_acquire(rtld_bind_lock, &lockstate); 2765 root = dlcheck(handle); 2766 if (root == NULL) { 2767 lock_release(rtld_bind_lock, &lockstate); 2768 return -1; 2769 } 2770 LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount, 2771 root->path); 2772 2773 /* Unreference the object and its dependencies. */ 2774 root->dl_refcount--; 2775 2776 if (root->refcount == 1) { 2777 /* 2778 * The object will be no longer referenced, so we must unload it. 2779 * First, call the fini functions. 2780 */ 2781 objlist_call_fini(&list_fini, root, &lockstate); 2782 2783 unref_dag(root); 2784 2785 /* Finish cleaning up the newly-unreferenced objects. */ 2786 GDB_STATE(RT_DELETE,&root->linkmap); 2787 unload_object(root); 2788 GDB_STATE(RT_CONSISTENT,NULL); 2789 } else 2790 unref_dag(root); 2791 2792 LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL); 2793 lock_release(rtld_bind_lock, &lockstate); 2794 return 0; 2795} 2796 2797char * 2798dlerror(void) 2799{ 2800 char *msg = error_message; 2801 error_message = NULL; 2802 return msg; 2803} 2804 2805/* 2806 * This function is deprecated and has no effect. 2807 */ 2808void 2809dllockinit(void *context, 2810 void *(*lock_create)(void *context), 2811 void (*rlock_acquire)(void *lock), 2812 void (*wlock_acquire)(void *lock), 2813 void (*lock_release)(void *lock), 2814 void (*lock_destroy)(void *lock), 2815 void (*context_destroy)(void *context)) 2816{ 2817 static void *cur_context; 2818 static void (*cur_context_destroy)(void *); 2819 2820 /* Just destroy the context from the previous call, if necessary. */ 2821 if (cur_context_destroy != NULL) 2822 cur_context_destroy(cur_context); 2823 cur_context = context; 2824 cur_context_destroy = context_destroy; 2825} 2826 2827void * 2828dlopen(const char *name, int mode) 2829{ 2830 2831 return (rtld_dlopen(name, -1, mode)); 2832} 2833 2834void * 2835fdlopen(int fd, int mode) 2836{ 2837 2838 return (rtld_dlopen(NULL, fd, mode)); 2839} 2840 2841static void * 2842rtld_dlopen(const char *name, int fd, int mode) 2843{ 2844 RtldLockState lockstate; 2845 int lo_flags; 2846 2847 LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name); 2848 ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1"; 2849 if (ld_tracing != NULL) { 2850 rlock_acquire(rtld_bind_lock, &lockstate); 2851 if (sigsetjmp(lockstate.env, 0) != 0) 2852 lock_upgrade(rtld_bind_lock, &lockstate); 2853 environ = (char **)*get_program_var_addr("environ", &lockstate); 2854 lock_release(rtld_bind_lock, &lockstate); 2855 } 2856 lo_flags = RTLD_LO_DLOPEN; 2857 if (mode & RTLD_NODELETE) 2858 lo_flags |= RTLD_LO_NODELETE; 2859 if (mode & RTLD_NOLOAD) 2860 lo_flags |= RTLD_LO_NOLOAD; 2861 if (ld_tracing != NULL) 2862 lo_flags |= RTLD_LO_TRACE; 2863 2864 return (dlopen_object(name, fd, obj_main, lo_flags, 2865 mode & (RTLD_MODEMASK | RTLD_GLOBAL), NULL)); 2866} 2867 2868static void 2869dlopen_cleanup(Obj_Entry *obj) 2870{ 2871 2872 obj->dl_refcount--; 2873 unref_dag(obj); 2874 if (obj->refcount == 0) 2875 unload_object(obj); 2876} 2877 2878static Obj_Entry * 2879dlopen_object(const char *name, int fd, Obj_Entry *refobj, int lo_flags, 2880 int mode, RtldLockState *lockstate) 2881{ 2882 Obj_Entry **old_obj_tail; 2883 Obj_Entry *obj; 2884 Objlist initlist; 2885 RtldLockState mlockstate; 2886 int result; 2887 2888 objlist_init(&initlist); 2889 2890 if (lockstate == NULL && !(lo_flags & RTLD_LO_EARLY)) { 2891 wlock_acquire(rtld_bind_lock, &mlockstate); 2892 lockstate = &mlockstate; 2893 } 2894 GDB_STATE(RT_ADD,NULL); 2895 2896 old_obj_tail = obj_tail; 2897 obj = NULL; 2898 if (name == NULL && fd == -1) { 2899 obj = obj_main; 2900 obj->refcount++; 2901 } else { 2902 obj = load_object(name, fd, refobj, lo_flags); 2903 } 2904 2905 if (obj) { 2906 obj->dl_refcount++; 2907 if (mode & RTLD_GLOBAL && objlist_find(&list_global, obj) == NULL) 2908 objlist_push_tail(&list_global, obj); 2909 if (*old_obj_tail != NULL) { /* We loaded something new. */ 2910 assert(*old_obj_tail == obj); 2911 result = load_needed_objects(obj, 2912 lo_flags & (RTLD_LO_DLOPEN | RTLD_LO_EARLY)); 2913 init_dag(obj); 2914 ref_dag(obj); 2915 if (result != -1) 2916 result = rtld_verify_versions(&obj->dagmembers); 2917 if (result != -1 && ld_tracing) 2918 goto trace; 2919 if (result == -1 || relocate_object_dag(obj, 2920 (mode & RTLD_MODEMASK) == RTLD_NOW, &obj_rtld, 2921 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 2922 lockstate) == -1) { 2923 dlopen_cleanup(obj); 2924 obj = NULL; 2925 } else if (lo_flags & RTLD_LO_EARLY) { 2926 /* 2927 * Do not call the init functions for early loaded 2928 * filtees. The image is still not initialized enough 2929 * for them to work. 2930 * 2931 * Our object is found by the global object list and 2932 * will be ordered among all init calls done right 2933 * before transferring control to main. 2934 */ 2935 } else { 2936 /* Make list of init functions to call. */ 2937 initlist_add_objects(obj, &obj->next, &initlist); 2938 } 2939 /* 2940 * Process all no_delete objects here, given them own 2941 * DAGs to prevent their dependencies from being unloaded. 2942 * This has to be done after we have loaded all of the 2943 * dependencies, so that we do not miss any. 2944 */ 2945 if (obj != NULL) 2946 process_nodelete(obj); 2947 } else { 2948 /* 2949 * Bump the reference counts for objects on this DAG. If 2950 * this is the first dlopen() call for the object that was 2951 * already loaded as a dependency, initialize the dag 2952 * starting at it. 2953 */ 2954 init_dag(obj); 2955 ref_dag(obj); 2956 2957 if ((lo_flags & RTLD_LO_TRACE) != 0) 2958 goto trace; 2959 } 2960 if (obj != NULL && ((lo_flags & RTLD_LO_NODELETE) != 0 || 2961 obj->z_nodelete) && !obj->ref_nodel) { 2962 dbg("obj %s nodelete", obj->path); 2963 ref_dag(obj); 2964 obj->z_nodelete = obj->ref_nodel = true; 2965 } 2966 } 2967 2968 LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0, 2969 name); 2970 GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL); 2971 2972 if (!(lo_flags & RTLD_LO_EARLY)) { 2973 map_stacks_exec(lockstate); 2974 } 2975 2976 if (initlist_objects_ifunc(&initlist, (mode & RTLD_MODEMASK) == RTLD_NOW, 2977 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0, 2978 lockstate) == -1) { 2979 objlist_clear(&initlist); 2980 dlopen_cleanup(obj); 2981 if (lockstate == &mlockstate) 2982 lock_release(rtld_bind_lock, lockstate); 2983 return (NULL); 2984 } 2985 2986 if (!(lo_flags & RTLD_LO_EARLY)) { 2987 /* Call the init functions. */ 2988 objlist_call_init(&initlist, lockstate); 2989 } 2990 objlist_clear(&initlist); 2991 if (lockstate == &mlockstate) 2992 lock_release(rtld_bind_lock, lockstate); 2993 return obj; 2994trace: 2995 trace_loaded_objects(obj); 2996 if (lockstate == &mlockstate) 2997 lock_release(rtld_bind_lock, lockstate); 2998 exit(0); 2999} 3000 3001static void * 3002do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve, 3003 int flags) 3004{ 3005 DoneList donelist; 3006 const Obj_Entry *obj, *defobj; 3007 const Elf_Sym *def; 3008 SymLook req; 3009 RtldLockState lockstate; 3010#ifndef __ia64__ 3011 tls_index ti; 3012#endif 3013 int res; 3014 3015 def = NULL; 3016 defobj = NULL; 3017 symlook_init(&req, name); 3018 req.ventry = ve; 3019 req.flags = flags | SYMLOOK_IN_PLT; 3020 req.lockstate = &lockstate; 3021 3022 rlock_acquire(rtld_bind_lock, &lockstate); 3023 if (sigsetjmp(lockstate.env, 0) != 0) 3024 lock_upgrade(rtld_bind_lock, &lockstate); 3025 if (handle == NULL || handle == RTLD_NEXT || 3026 handle == RTLD_DEFAULT || handle == RTLD_SELF) { 3027 3028 if ((obj = obj_from_addr(retaddr)) == NULL) { 3029 _rtld_error("Cannot determine caller's shared object"); 3030 lock_release(rtld_bind_lock, &lockstate); 3031 return NULL; 3032 } 3033 if (handle == NULL) { /* Just the caller's shared object. */ 3034 res = symlook_obj(&req, obj); 3035 if (res == 0) { 3036 def = req.sym_out; 3037 defobj = req.defobj_out; 3038 } 3039 } else if (handle == RTLD_NEXT || /* Objects after caller's */ 3040 handle == RTLD_SELF) { /* ... caller included */ 3041 if (handle == RTLD_NEXT) 3042 obj = obj->next; 3043 for (; obj != NULL; obj = obj->next) { 3044 res = symlook_obj(&req, obj); 3045 if (res == 0) { 3046 if (def == NULL || 3047 ELF_ST_BIND(req.sym_out->st_info) != STB_WEAK) { 3048 def = req.sym_out; 3049 defobj = req.defobj_out; 3050 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 3051 break; 3052 } 3053 } 3054 } 3055 /* 3056 * Search the dynamic linker itself, and possibly resolve the 3057 * symbol from there. This is how the application links to 3058 * dynamic linker services such as dlopen. 3059 */ 3060 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 3061 res = symlook_obj(&req, &obj_rtld); 3062 if (res == 0) { 3063 def = req.sym_out; 3064 defobj = req.defobj_out; 3065 } 3066 } 3067 } else { 3068 assert(handle == RTLD_DEFAULT); 3069 res = symlook_default(&req, obj); 3070 if (res == 0) { 3071 defobj = req.defobj_out; 3072 def = req.sym_out; 3073 } 3074 } 3075 } else { 3076 if ((obj = dlcheck(handle)) == NULL) { 3077 lock_release(rtld_bind_lock, &lockstate); 3078 return NULL; 3079 } 3080 3081 donelist_init(&donelist); 3082 if (obj->mainprog) { 3083 /* Handle obtained by dlopen(NULL, ...) implies global scope. */ 3084 res = symlook_global(&req, &donelist); 3085 if (res == 0) { 3086 def = req.sym_out; 3087 defobj = req.defobj_out; 3088 } 3089 /* 3090 * Search the dynamic linker itself, and possibly resolve the 3091 * symbol from there. This is how the application links to 3092 * dynamic linker services such as dlopen. 3093 */ 3094 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) { 3095 res = symlook_obj(&req, &obj_rtld); 3096 if (res == 0) { 3097 def = req.sym_out; 3098 defobj = req.defobj_out; 3099 } 3100 } 3101 } 3102 else { 3103 /* Search the whole DAG rooted at the given object. */ 3104 res = symlook_list(&req, &obj->dagmembers, &donelist); 3105 if (res == 0) { 3106 def = req.sym_out; 3107 defobj = req.defobj_out; 3108 } 3109 } 3110 } 3111 3112 if (def != NULL) { 3113 lock_release(rtld_bind_lock, &lockstate); 3114 3115 /* 3116 * The value required by the caller is derived from the value 3117 * of the symbol. For the ia64 architecture, we need to 3118 * construct a function descriptor which the caller can use to 3119 * call the function with the right 'gp' value. For other 3120 * architectures and for non-functions, the value is simply 3121 * the relocated value of the symbol. 3122 */ 3123 if (ELF_ST_TYPE(def->st_info) == STT_FUNC) 3124 return (make_function_pointer(def, defobj)); 3125 else if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) 3126 return (rtld_resolve_ifunc(defobj, def)); 3127 else if (ELF_ST_TYPE(def->st_info) == STT_TLS) { 3128#ifdef __ia64__ 3129 return (__tls_get_addr(defobj->tlsindex, def->st_value)); 3130#else 3131 ti.ti_module = defobj->tlsindex; 3132 ti.ti_offset = def->st_value; 3133 return (__tls_get_addr(&ti)); 3134#endif 3135 } else 3136 return (defobj->relocbase + def->st_value); 3137 } 3138 3139 _rtld_error("Undefined symbol \"%s\"", name); 3140 lock_release(rtld_bind_lock, &lockstate); 3141 return NULL; 3142} 3143 3144void * 3145dlsym(void *handle, const char *name) 3146{ 3147 return do_dlsym(handle, name, __builtin_return_address(0), NULL, 3148 SYMLOOK_DLSYM); 3149} 3150 3151dlfunc_t 3152dlfunc(void *handle, const char *name) 3153{ 3154 union { 3155 void *d; 3156 dlfunc_t f; 3157 } rv; 3158 3159 rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL, 3160 SYMLOOK_DLSYM); 3161 return (rv.f); 3162} 3163 3164void * 3165dlvsym(void *handle, const char *name, const char *version) 3166{ 3167 Ver_Entry ventry; 3168 3169 ventry.name = version; 3170 ventry.file = NULL; 3171 ventry.hash = elf_hash(version); 3172 ventry.flags= 0; 3173 return do_dlsym(handle, name, __builtin_return_address(0), &ventry, 3174 SYMLOOK_DLSYM); 3175} 3176 3177int 3178_rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info) 3179{ 3180 const Obj_Entry *obj; 3181 RtldLockState lockstate; 3182 3183 rlock_acquire(rtld_bind_lock, &lockstate); 3184 obj = obj_from_addr(addr); 3185 if (obj == NULL) { 3186 _rtld_error("No shared object contains address"); 3187 lock_release(rtld_bind_lock, &lockstate); 3188 return (0); 3189 } 3190 rtld_fill_dl_phdr_info(obj, phdr_info); 3191 lock_release(rtld_bind_lock, &lockstate); 3192 return (1); 3193} 3194 3195int 3196dladdr(const void *addr, Dl_info *info) 3197{ 3198 const Obj_Entry *obj; 3199 const Elf_Sym *def; 3200 void *symbol_addr; 3201 unsigned long symoffset; 3202 RtldLockState lockstate; 3203 3204 rlock_acquire(rtld_bind_lock, &lockstate); 3205 obj = obj_from_addr(addr); 3206 if (obj == NULL) { 3207 _rtld_error("No shared object contains address"); 3208 lock_release(rtld_bind_lock, &lockstate); 3209 return 0; 3210 } 3211 info->dli_fname = obj->path; 3212 info->dli_fbase = obj->mapbase; 3213 info->dli_saddr = (void *)0; 3214 info->dli_sname = NULL; 3215 3216 /* 3217 * Walk the symbol list looking for the symbol whose address is 3218 * closest to the address sent in. 3219 */ 3220 for (symoffset = 0; symoffset < obj->dynsymcount; symoffset++) { 3221 def = obj->symtab + symoffset; 3222 3223 /* 3224 * For skip the symbol if st_shndx is either SHN_UNDEF or 3225 * SHN_COMMON. 3226 */ 3227 if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON) 3228 continue; 3229 3230 /* 3231 * If the symbol is greater than the specified address, or if it 3232 * is further away from addr than the current nearest symbol, 3233 * then reject it. 3234 */ 3235 symbol_addr = obj->relocbase + def->st_value; 3236 if (symbol_addr > addr || symbol_addr < info->dli_saddr) 3237 continue; 3238 3239 /* Update our idea of the nearest symbol. */ 3240 info->dli_sname = obj->strtab + def->st_name; 3241 info->dli_saddr = symbol_addr; 3242 3243 /* Exact match? */ 3244 if (info->dli_saddr == addr) 3245 break; 3246 } 3247 lock_release(rtld_bind_lock, &lockstate); 3248 return 1; 3249} 3250 3251int 3252dlinfo(void *handle, int request, void *p) 3253{ 3254 const Obj_Entry *obj; 3255 RtldLockState lockstate; 3256 int error; 3257 3258 rlock_acquire(rtld_bind_lock, &lockstate); 3259 3260 if (handle == NULL || handle == RTLD_SELF) { 3261 void *retaddr; 3262 3263 retaddr = __builtin_return_address(0); /* __GNUC__ only */ 3264 if ((obj = obj_from_addr(retaddr)) == NULL) 3265 _rtld_error("Cannot determine caller's shared object"); 3266 } else 3267 obj = dlcheck(handle); 3268 3269 if (obj == NULL) { 3270 lock_release(rtld_bind_lock, &lockstate); 3271 return (-1); 3272 } 3273 3274 error = 0; 3275 switch (request) { 3276 case RTLD_DI_LINKMAP: 3277 *((struct link_map const **)p) = &obj->linkmap; 3278 break; 3279 case RTLD_DI_ORIGIN: 3280 error = rtld_dirname(obj->path, p); 3281 break; 3282 3283 case RTLD_DI_SERINFOSIZE: 3284 case RTLD_DI_SERINFO: 3285 error = do_search_info(obj, request, (struct dl_serinfo *)p); 3286 break; 3287 3288 default: 3289 _rtld_error("Invalid request %d passed to dlinfo()", request); 3290 error = -1; 3291 } 3292 3293 lock_release(rtld_bind_lock, &lockstate); 3294 3295 return (error); 3296} 3297 3298static void 3299rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info) 3300{ 3301 3302 phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase; 3303 phdr_info->dlpi_name = obj->path; 3304 phdr_info->dlpi_phdr = obj->phdr; 3305 phdr_info->dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]); 3306 phdr_info->dlpi_tls_modid = obj->tlsindex; 3307 phdr_info->dlpi_tls_data = obj->tlsinit; 3308 phdr_info->dlpi_adds = obj_loads; 3309 phdr_info->dlpi_subs = obj_loads - obj_count; 3310} 3311 3312int 3313dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param) 3314{ 3315 struct dl_phdr_info phdr_info; 3316 const Obj_Entry *obj; 3317 RtldLockState bind_lockstate, phdr_lockstate; 3318 int error; 3319 3320 wlock_acquire(rtld_phdr_lock, &phdr_lockstate); 3321 rlock_acquire(rtld_bind_lock, &bind_lockstate); 3322 3323 error = 0; 3324 3325 for (obj = obj_list; obj != NULL; obj = obj->next) { 3326 rtld_fill_dl_phdr_info(obj, &phdr_info); 3327 if ((error = callback(&phdr_info, sizeof phdr_info, param)) != 0) 3328 break; 3329 3330 } 3331 lock_release(rtld_bind_lock, &bind_lockstate); 3332 lock_release(rtld_phdr_lock, &phdr_lockstate); 3333 3334 return (error); 3335} 3336 3337static void * 3338fill_search_info(const char *dir, size_t dirlen, void *param) 3339{ 3340 struct fill_search_info_args *arg; 3341 3342 arg = param; 3343 3344 if (arg->request == RTLD_DI_SERINFOSIZE) { 3345 arg->serinfo->dls_cnt ++; 3346 arg->serinfo->dls_size += sizeof(struct dl_serpath) + dirlen + 1; 3347 } else { 3348 struct dl_serpath *s_entry; 3349 3350 s_entry = arg->serpath; 3351 s_entry->dls_name = arg->strspace; 3352 s_entry->dls_flags = arg->flags; 3353 3354 strncpy(arg->strspace, dir, dirlen); 3355 arg->strspace[dirlen] = '\0'; 3356 3357 arg->strspace += dirlen + 1; 3358 arg->serpath++; 3359 } 3360 3361 return (NULL); 3362} 3363 3364static int 3365do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info) 3366{ 3367 struct dl_serinfo _info; 3368 struct fill_search_info_args args; 3369 3370 args.request = RTLD_DI_SERINFOSIZE; 3371 args.serinfo = &_info; 3372 3373 _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath); 3374 _info.dls_cnt = 0; 3375 3376 path_enumerate(obj->rpath, fill_search_info, &args); 3377 path_enumerate(ld_library_path, fill_search_info, &args); 3378 path_enumerate(obj->runpath, fill_search_info, &args); 3379 path_enumerate(gethints(obj->z_nodeflib), fill_search_info, &args); 3380 if (!obj->z_nodeflib) 3381 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args); 3382 3383 3384 if (request == RTLD_DI_SERINFOSIZE) { 3385 info->dls_size = _info.dls_size; 3386 info->dls_cnt = _info.dls_cnt; 3387 return (0); 3388 } 3389 3390 if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) { 3391 _rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()"); 3392 return (-1); 3393 } 3394 3395 args.request = RTLD_DI_SERINFO; 3396 args.serinfo = info; 3397 args.serpath = &info->dls_serpath[0]; 3398 args.strspace = (char *)&info->dls_serpath[_info.dls_cnt]; 3399 3400 args.flags = LA_SER_RUNPATH; 3401 if (path_enumerate(obj->rpath, fill_search_info, &args) != NULL) 3402 return (-1); 3403 3404 args.flags = LA_SER_LIBPATH; 3405 if (path_enumerate(ld_library_path, fill_search_info, &args) != NULL) 3406 return (-1); 3407 3408 args.flags = LA_SER_RUNPATH; 3409 if (path_enumerate(obj->runpath, fill_search_info, &args) != NULL) 3410 return (-1); 3411 3412 args.flags = LA_SER_CONFIG; 3413 if (path_enumerate(gethints(obj->z_nodeflib), fill_search_info, &args) 3414 != NULL) 3415 return (-1); 3416 3417 args.flags = LA_SER_DEFAULT; 3418 if (!obj->z_nodeflib && 3419 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args) != NULL) 3420 return (-1); 3421 return (0); 3422} 3423 3424static int 3425rtld_dirname(const char *path, char *bname) 3426{ 3427 const char *endp; 3428 3429 /* Empty or NULL string gets treated as "." */ 3430 if (path == NULL || *path == '\0') { 3431 bname[0] = '.'; 3432 bname[1] = '\0'; 3433 return (0); 3434 } 3435 3436 /* Strip trailing slashes */ 3437 endp = path + strlen(path) - 1; 3438 while (endp > path && *endp == '/') 3439 endp--; 3440 3441 /* Find the start of the dir */ 3442 while (endp > path && *endp != '/') 3443 endp--; 3444 3445 /* Either the dir is "/" or there are no slashes */ 3446 if (endp == path) { 3447 bname[0] = *endp == '/' ? '/' : '.'; 3448 bname[1] = '\0'; 3449 return (0); 3450 } else { 3451 do { 3452 endp--; 3453 } while (endp > path && *endp == '/'); 3454 } 3455 3456 if (endp - path + 2 > PATH_MAX) 3457 { 3458 _rtld_error("Filename is too long: %s", path); 3459 return(-1); 3460 } 3461 3462 strncpy(bname, path, endp - path + 1); 3463 bname[endp - path + 1] = '\0'; 3464 return (0); 3465} 3466 3467static int 3468rtld_dirname_abs(const char *path, char *base) 3469{ 3470 char *last; 3471 3472 if (realpath(path, base) == NULL) 3473 return (-1); 3474 dbg("%s -> %s", path, base); 3475 last = strrchr(base, '/'); 3476 if (last == NULL) 3477 return (-1); 3478 if (last != base) 3479 *last = '\0'; 3480 return (0); 3481} 3482 3483static void 3484linkmap_add(Obj_Entry *obj) 3485{ 3486 struct link_map *l = &obj->linkmap; 3487 struct link_map *prev; 3488 3489 obj->linkmap.l_name = obj->path; 3490 obj->linkmap.l_addr = obj->mapbase; 3491 obj->linkmap.l_ld = obj->dynamic; 3492#ifdef __mips__ 3493 /* GDB needs load offset on MIPS to use the symbols */ 3494 obj->linkmap.l_offs = obj->relocbase; 3495#endif 3496 3497 if (r_debug.r_map == NULL) { 3498 r_debug.r_map = l; 3499 return; 3500 } 3501 3502 /* 3503 * Scan to the end of the list, but not past the entry for the 3504 * dynamic linker, which we want to keep at the very end. 3505 */ 3506 for (prev = r_debug.r_map; 3507 prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap; 3508 prev = prev->l_next) 3509 ; 3510 3511 /* Link in the new entry. */ 3512 l->l_prev = prev; 3513 l->l_next = prev->l_next; 3514 if (l->l_next != NULL) 3515 l->l_next->l_prev = l; 3516 prev->l_next = l; 3517} 3518 3519static void 3520linkmap_delete(Obj_Entry *obj) 3521{ 3522 struct link_map *l = &obj->linkmap; 3523 3524 if (l->l_prev == NULL) { 3525 if ((r_debug.r_map = l->l_next) != NULL) 3526 l->l_next->l_prev = NULL; 3527 return; 3528 } 3529 3530 if ((l->l_prev->l_next = l->l_next) != NULL) 3531 l->l_next->l_prev = l->l_prev; 3532} 3533 3534/* 3535 * Function for the debugger to set a breakpoint on to gain control. 3536 * 3537 * The two parameters allow the debugger to easily find and determine 3538 * what the runtime loader is doing and to whom it is doing it. 3539 * 3540 * When the loadhook trap is hit (r_debug_state, set at program 3541 * initialization), the arguments can be found on the stack: 3542 * 3543 * +8 struct link_map *m 3544 * +4 struct r_debug *rd 3545 * +0 RetAddr 3546 */ 3547void 3548r_debug_state(struct r_debug* rd, struct link_map *m) 3549{ 3550 /* 3551 * The following is a hack to force the compiler to emit calls to 3552 * this function, even when optimizing. If the function is empty, 3553 * the compiler is not obliged to emit any code for calls to it, 3554 * even when marked __noinline. However, gdb depends on those 3555 * calls being made. 3556 */ 3557 __compiler_membar(); 3558} 3559 3560/* 3561 * A function called after init routines have completed. This can be used to 3562 * break before a program's entry routine is called, and can be used when 3563 * main is not available in the symbol table. 3564 */ 3565void 3566_r_debug_postinit(struct link_map *m) 3567{ 3568 3569 /* See r_debug_state(). */ 3570 __compiler_membar(); 3571} 3572 3573/* 3574 * Get address of the pointer variable in the main program. 3575 * Prefer non-weak symbol over the weak one. 3576 */ 3577static const void ** 3578get_program_var_addr(const char *name, RtldLockState *lockstate) 3579{ 3580 SymLook req; 3581 DoneList donelist; 3582 3583 symlook_init(&req, name); 3584 req.lockstate = lockstate; 3585 donelist_init(&donelist); 3586 if (symlook_global(&req, &donelist) != 0) 3587 return (NULL); 3588 if (ELF_ST_TYPE(req.sym_out->st_info) == STT_FUNC) 3589 return ((const void **)make_function_pointer(req.sym_out, 3590 req.defobj_out)); 3591 else if (ELF_ST_TYPE(req.sym_out->st_info) == STT_GNU_IFUNC) 3592 return ((const void **)rtld_resolve_ifunc(req.defobj_out, req.sym_out)); 3593 else 3594 return ((const void **)(req.defobj_out->relocbase + 3595 req.sym_out->st_value)); 3596} 3597 3598/* 3599 * Set a pointer variable in the main program to the given value. This 3600 * is used to set key variables such as "environ" before any of the 3601 * init functions are called. 3602 */ 3603static void 3604set_program_var(const char *name, const void *value) 3605{ 3606 const void **addr; 3607 3608 if ((addr = get_program_var_addr(name, NULL)) != NULL) { 3609 dbg("\"%s\": *%p <-- %p", name, addr, value); 3610 *addr = value; 3611 } 3612} 3613 3614/* 3615 * Search the global objects, including dependencies and main object, 3616 * for the given symbol. 3617 */ 3618static int 3619symlook_global(SymLook *req, DoneList *donelist) 3620{ 3621 SymLook req1; 3622 const Objlist_Entry *elm; 3623 int res; 3624 3625 symlook_init_from_req(&req1, req); 3626 3627 /* Search all objects loaded at program start up. */ 3628 if (req->defobj_out == NULL || 3629 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 3630 res = symlook_list(&req1, &list_main, donelist); 3631 if (res == 0 && (req->defobj_out == NULL || 3632 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 3633 req->sym_out = req1.sym_out; 3634 req->defobj_out = req1.defobj_out; 3635 assert(req->defobj_out != NULL); 3636 } 3637 } 3638 3639 /* Search all DAGs whose roots are RTLD_GLOBAL objects. */ 3640 STAILQ_FOREACH(elm, &list_global, link) { 3641 if (req->defobj_out != NULL && 3642 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK) 3643 break; 3644 res = symlook_list(&req1, &elm->obj->dagmembers, donelist); 3645 if (res == 0 && (req->defobj_out == NULL || 3646 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 3647 req->sym_out = req1.sym_out; 3648 req->defobj_out = req1.defobj_out; 3649 assert(req->defobj_out != NULL); 3650 } 3651 } 3652 3653 return (req->sym_out != NULL ? 0 : ESRCH); 3654} 3655 3656/* 3657 * Given a symbol name in a referencing object, find the corresponding 3658 * definition of the symbol. Returns a pointer to the symbol, or NULL if 3659 * no definition was found. Returns a pointer to the Obj_Entry of the 3660 * defining object via the reference parameter DEFOBJ_OUT. 3661 */ 3662static int 3663symlook_default(SymLook *req, const Obj_Entry *refobj) 3664{ 3665 DoneList donelist; 3666 const Objlist_Entry *elm; 3667 SymLook req1; 3668 int res; 3669 3670 donelist_init(&donelist); 3671 symlook_init_from_req(&req1, req); 3672 3673 /* Look first in the referencing object if linked symbolically. */ 3674 if (refobj->symbolic && !donelist_check(&donelist, refobj)) { 3675 res = symlook_obj(&req1, refobj); 3676 if (res == 0) { 3677 req->sym_out = req1.sym_out; 3678 req->defobj_out = req1.defobj_out; 3679 assert(req->defobj_out != NULL); 3680 } 3681 } 3682 3683 symlook_global(req, &donelist); 3684 3685 /* Search all dlopened DAGs containing the referencing object. */ 3686 STAILQ_FOREACH(elm, &refobj->dldags, link) { 3687 if (req->sym_out != NULL && 3688 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK) 3689 break; 3690 res = symlook_list(&req1, &elm->obj->dagmembers, &donelist); 3691 if (res == 0 && (req->sym_out == NULL || 3692 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) { 3693 req->sym_out = req1.sym_out; 3694 req->defobj_out = req1.defobj_out; 3695 assert(req->defobj_out != NULL); 3696 } 3697 } 3698 3699 /* 3700 * Search the dynamic linker itself, and possibly resolve the 3701 * symbol from there. This is how the application links to 3702 * dynamic linker services such as dlopen. 3703 */ 3704 if (req->sym_out == NULL || 3705 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) { 3706 res = symlook_obj(&req1, &obj_rtld); 3707 if (res == 0) { 3708 req->sym_out = req1.sym_out; 3709 req->defobj_out = req1.defobj_out; 3710 assert(req->defobj_out != NULL); 3711 } 3712 } 3713 3714 return (req->sym_out != NULL ? 0 : ESRCH); 3715} 3716 3717static int 3718symlook_list(SymLook *req, const Objlist *objlist, DoneList *dlp) 3719{ 3720 const Elf_Sym *def; 3721 const Obj_Entry *defobj; 3722 const Objlist_Entry *elm; 3723 SymLook req1; 3724 int res; 3725 3726 def = NULL; 3727 defobj = NULL; 3728 STAILQ_FOREACH(elm, objlist, link) { 3729 if (donelist_check(dlp, elm->obj)) 3730 continue; 3731 symlook_init_from_req(&req1, req); 3732 if ((res = symlook_obj(&req1, elm->obj)) == 0) { 3733 if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) { 3734 def = req1.sym_out; 3735 defobj = req1.defobj_out; 3736 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 3737 break; 3738 } 3739 } 3740 } 3741 if (def != NULL) { 3742 req->sym_out = def; 3743 req->defobj_out = defobj; 3744 return (0); 3745 } 3746 return (ESRCH); 3747} 3748 3749/* 3750 * Search the chain of DAGS cointed to by the given Needed_Entry 3751 * for a symbol of the given name. Each DAG is scanned completely 3752 * before advancing to the next one. Returns a pointer to the symbol, 3753 * or NULL if no definition was found. 3754 */ 3755static int 3756symlook_needed(SymLook *req, const Needed_Entry *needed, DoneList *dlp) 3757{ 3758 const Elf_Sym *def; 3759 const Needed_Entry *n; 3760 const Obj_Entry *defobj; 3761 SymLook req1; 3762 int res; 3763 3764 def = NULL; 3765 defobj = NULL; 3766 symlook_init_from_req(&req1, req); 3767 for (n = needed; n != NULL; n = n->next) { 3768 if (n->obj == NULL || 3769 (res = symlook_list(&req1, &n->obj->dagmembers, dlp)) != 0) 3770 continue; 3771 if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) { 3772 def = req1.sym_out; 3773 defobj = req1.defobj_out; 3774 if (ELF_ST_BIND(def->st_info) != STB_WEAK) 3775 break; 3776 } 3777 } 3778 if (def != NULL) { 3779 req->sym_out = def; 3780 req->defobj_out = defobj; 3781 return (0); 3782 } 3783 return (ESRCH); 3784} 3785 3786/* 3787 * Search the symbol table of a single shared object for a symbol of 3788 * the given name and version, if requested. Returns a pointer to the 3789 * symbol, or NULL if no definition was found. If the object is 3790 * filter, return filtered symbol from filtee. 3791 * 3792 * The symbol's hash value is passed in for efficiency reasons; that 3793 * eliminates many recomputations of the hash value. 3794 */ 3795int 3796symlook_obj(SymLook *req, const Obj_Entry *obj) 3797{ 3798 DoneList donelist; 3799 SymLook req1; 3800 int flags, res, mres; 3801 3802 /* 3803 * If there is at least one valid hash at this point, we prefer to 3804 * use the faster GNU version if available. 3805 */ 3806 if (obj->valid_hash_gnu) 3807 mres = symlook_obj1_gnu(req, obj); 3808 else if (obj->valid_hash_sysv) 3809 mres = symlook_obj1_sysv(req, obj); 3810 else 3811 return (EINVAL); 3812 3813 if (mres == 0) { 3814 if (obj->needed_filtees != NULL) { 3815 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; 3816 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 3817 donelist_init(&donelist); 3818 symlook_init_from_req(&req1, req); 3819 res = symlook_needed(&req1, obj->needed_filtees, &donelist); 3820 if (res == 0) { 3821 req->sym_out = req1.sym_out; 3822 req->defobj_out = req1.defobj_out; 3823 } 3824 return (res); 3825 } 3826 if (obj->needed_aux_filtees != NULL) { 3827 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0; 3828 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate); 3829 donelist_init(&donelist); 3830 symlook_init_from_req(&req1, req); 3831 res = symlook_needed(&req1, obj->needed_aux_filtees, &donelist); 3832 if (res == 0) { 3833 req->sym_out = req1.sym_out; 3834 req->defobj_out = req1.defobj_out; 3835 return (res); 3836 } 3837 } 3838 } 3839 return (mres); 3840} 3841 3842/* Symbol match routine common to both hash functions */ 3843static bool 3844matched_symbol(SymLook *req, const Obj_Entry *obj, Sym_Match_Result *result, 3845 const unsigned long symnum) 3846{ 3847 Elf_Versym verndx; 3848 const Elf_Sym *symp; 3849 const char *strp; 3850 3851 symp = obj->symtab + symnum; 3852 strp = obj->strtab + symp->st_name; 3853 3854 switch (ELF_ST_TYPE(symp->st_info)) { 3855 case STT_FUNC: 3856 case STT_NOTYPE: 3857 case STT_OBJECT: 3858 case STT_COMMON: 3859 case STT_GNU_IFUNC: 3860 if (symp->st_value == 0) 3861 return (false); 3862 /* fallthrough */ 3863 case STT_TLS: 3864 if (symp->st_shndx != SHN_UNDEF) 3865 break; 3866#ifndef __mips__ 3867 else if (((req->flags & SYMLOOK_IN_PLT) == 0) && 3868 (ELF_ST_TYPE(symp->st_info) == STT_FUNC)) 3869 break; 3870 /* fallthrough */ 3871#endif 3872 default: 3873 return (false); 3874 } 3875 if (req->name[0] != strp[0] || strcmp(req->name, strp) != 0) 3876 return (false); 3877 3878 if (req->ventry == NULL) { 3879 if (obj->versyms != NULL) { 3880 verndx = VER_NDX(obj->versyms[symnum]); 3881 if (verndx > obj->vernum) { 3882 _rtld_error( 3883 "%s: symbol %s references wrong version %d", 3884 obj->path, obj->strtab + symnum, verndx); 3885 return (false); 3886 } 3887 /* 3888 * If we are not called from dlsym (i.e. this 3889 * is a normal relocation from unversioned 3890 * binary), accept the symbol immediately if 3891 * it happens to have first version after this 3892 * shared object became versioned. Otherwise, 3893 * if symbol is versioned and not hidden, 3894 * remember it. If it is the only symbol with 3895 * this name exported by the shared object, it 3896 * will be returned as a match by the calling 3897 * function. If symbol is global (verndx < 2) 3898 * accept it unconditionally. 3899 */ 3900 if ((req->flags & SYMLOOK_DLSYM) == 0 && 3901 verndx == VER_NDX_GIVEN) { 3902 result->sym_out = symp; 3903 return (true); 3904 } 3905 else if (verndx >= VER_NDX_GIVEN) { 3906 if ((obj->versyms[symnum] & VER_NDX_HIDDEN) 3907 == 0) { 3908 if (result->vsymp == NULL) 3909 result->vsymp = symp; 3910 result->vcount++; 3911 } 3912 return (false); 3913 } 3914 } 3915 result->sym_out = symp; 3916 return (true); 3917 } 3918 if (obj->versyms == NULL) { 3919 if (object_match_name(obj, req->ventry->name)) { 3920 _rtld_error("%s: object %s should provide version %s " 3921 "for symbol %s", obj_rtld.path, obj->path, 3922 req->ventry->name, obj->strtab + symnum); 3923 return (false); 3924 } 3925 } else { 3926 verndx = VER_NDX(obj->versyms[symnum]); 3927 if (verndx > obj->vernum) { 3928 _rtld_error("%s: symbol %s references wrong version %d", 3929 obj->path, obj->strtab + symnum, verndx); 3930 return (false); 3931 } 3932 if (obj->vertab[verndx].hash != req->ventry->hash || 3933 strcmp(obj->vertab[verndx].name, req->ventry->name)) { 3934 /* 3935 * Version does not match. Look if this is a 3936 * global symbol and if it is not hidden. If 3937 * global symbol (verndx < 2) is available, 3938 * use it. Do not return symbol if we are 3939 * called by dlvsym, because dlvsym looks for 3940 * a specific version and default one is not 3941 * what dlvsym wants. 3942 */ 3943 if ((req->flags & SYMLOOK_DLSYM) || 3944 (verndx >= VER_NDX_GIVEN) || 3945 (obj->versyms[symnum] & VER_NDX_HIDDEN)) 3946 return (false); 3947 } 3948 } 3949 result->sym_out = symp; 3950 return (true); 3951} 3952 3953/* 3954 * Search for symbol using SysV hash function. 3955 * obj->buckets is known not to be NULL at this point; the test for this was 3956 * performed with the obj->valid_hash_sysv assignment. 3957 */ 3958static int 3959symlook_obj1_sysv(SymLook *req, const Obj_Entry *obj) 3960{ 3961 unsigned long symnum; 3962 Sym_Match_Result matchres; 3963 3964 matchres.sym_out = NULL; 3965 matchres.vsymp = NULL; 3966 matchres.vcount = 0; 3967 3968 for (symnum = obj->buckets[req->hash % obj->nbuckets]; 3969 symnum != STN_UNDEF; symnum = obj->chains[symnum]) { 3970 if (symnum >= obj->nchains) 3971 return (ESRCH); /* Bad object */ 3972 3973 if (matched_symbol(req, obj, &matchres, symnum)) { 3974 req->sym_out = matchres.sym_out; 3975 req->defobj_out = obj; 3976 return (0); 3977 } 3978 } 3979 if (matchres.vcount == 1) { 3980 req->sym_out = matchres.vsymp; 3981 req->defobj_out = obj; 3982 return (0); 3983 } 3984 return (ESRCH); 3985} 3986 3987/* Search for symbol using GNU hash function */ 3988static int 3989symlook_obj1_gnu(SymLook *req, const Obj_Entry *obj) 3990{ 3991 Elf_Addr bloom_word; 3992 const Elf32_Word *hashval; 3993 Elf32_Word bucket; 3994 Sym_Match_Result matchres; 3995 unsigned int h1, h2; 3996 unsigned long symnum; 3997 3998 matchres.sym_out = NULL; 3999 matchres.vsymp = NULL; 4000 matchres.vcount = 0; 4001 4002 /* Pick right bitmask word from Bloom filter array */ 4003 bloom_word = obj->bloom_gnu[(req->hash_gnu / __ELF_WORD_SIZE) & 4004 obj->maskwords_bm_gnu]; 4005 4006 /* Calculate modulus word size of gnu hash and its derivative */ 4007 h1 = req->hash_gnu & (__ELF_WORD_SIZE - 1); 4008 h2 = ((req->hash_gnu >> obj->shift2_gnu) & (__ELF_WORD_SIZE - 1)); 4009 4010 /* Filter out the "definitely not in set" queries */ 4011 if (((bloom_word >> h1) & (bloom_word >> h2) & 1) == 0) 4012 return (ESRCH); 4013 4014 /* Locate hash chain and corresponding value element*/ 4015 bucket = obj->buckets_gnu[req->hash_gnu % obj->nbuckets_gnu]; 4016 if (bucket == 0) 4017 return (ESRCH); 4018 hashval = &obj->chain_zero_gnu[bucket]; 4019 do { 4020 if (((*hashval ^ req->hash_gnu) >> 1) == 0) { 4021 symnum = hashval - obj->chain_zero_gnu; 4022 if (matched_symbol(req, obj, &matchres, symnum)) { 4023 req->sym_out = matchres.sym_out; 4024 req->defobj_out = obj; 4025 return (0); 4026 } 4027 } 4028 } while ((*hashval++ & 1) == 0); 4029 if (matchres.vcount == 1) { 4030 req->sym_out = matchres.vsymp; 4031 req->defobj_out = obj; 4032 return (0); 4033 } 4034 return (ESRCH); 4035} 4036 4037static void 4038trace_loaded_objects(Obj_Entry *obj) 4039{ 4040 char *fmt1, *fmt2, *fmt, *main_local, *list_containers; 4041 int c; 4042 4043 if ((main_local = getenv(LD_ "TRACE_LOADED_OBJECTS_PROGNAME")) == NULL) 4044 main_local = ""; 4045 4046 if ((fmt1 = getenv(LD_ "TRACE_LOADED_OBJECTS_FMT1")) == NULL) 4047 fmt1 = "\t%o => %p (%x)\n"; 4048 4049 if ((fmt2 = getenv(LD_ "TRACE_LOADED_OBJECTS_FMT2")) == NULL) 4050 fmt2 = "\t%o (%x)\n"; 4051 4052 list_containers = getenv(LD_ "TRACE_LOADED_OBJECTS_ALL"); 4053 4054 for (; obj; obj = obj->next) { 4055 Needed_Entry *needed; 4056 char *name, *path; 4057 bool is_lib; 4058 4059 if (list_containers && obj->needed != NULL) 4060 rtld_printf("%s:\n", obj->path); 4061 for (needed = obj->needed; needed; needed = needed->next) { 4062 if (needed->obj != NULL) { 4063 if (needed->obj->traced && !list_containers) 4064 continue; 4065 needed->obj->traced = true; 4066 path = needed->obj->path; 4067 } else 4068 path = "not found"; 4069 4070 name = (char *)obj->strtab + needed->name; 4071 is_lib = strncmp(name, "lib", 3) == 0; /* XXX - bogus */ 4072 4073 fmt = is_lib ? fmt1 : fmt2; 4074 while ((c = *fmt++) != '\0') { 4075 switch (c) { 4076 default: 4077 rtld_putchar(c); 4078 continue; 4079 case '\\': 4080 switch (c = *fmt) { 4081 case '\0': 4082 continue; 4083 case 'n': 4084 rtld_putchar('\n'); 4085 break; 4086 case 't': 4087 rtld_putchar('\t'); 4088 break; 4089 } 4090 break; 4091 case '%': 4092 switch (c = *fmt) { 4093 case '\0': 4094 continue; 4095 case '%': 4096 default: 4097 rtld_putchar(c); 4098 break; 4099 case 'A': 4100 rtld_putstr(main_local); 4101 break; 4102 case 'a': 4103 rtld_putstr(obj_main->path); 4104 break; 4105 case 'o': 4106 rtld_putstr(name); 4107 break; 4108#if 0 4109 case 'm': 4110 rtld_printf("%d", sodp->sod_major); 4111 break; 4112 case 'n': 4113 rtld_printf("%d", sodp->sod_minor); 4114 break; 4115#endif 4116 case 'p': 4117 rtld_putstr(path); 4118 break; 4119 case 'x': 4120 rtld_printf("%p", needed->obj ? needed->obj->mapbase : 4121 0); 4122 break; 4123 } 4124 break; 4125 } 4126 ++fmt; 4127 } 4128 } 4129 } 4130} 4131 4132/* 4133 * Unload a dlopened object and its dependencies from memory and from 4134 * our data structures. It is assumed that the DAG rooted in the 4135 * object has already been unreferenced, and that the object has a 4136 * reference count of 0. 4137 */ 4138static void 4139unload_object(Obj_Entry *root) 4140{ 4141 Obj_Entry *obj; 4142 Obj_Entry **linkp; 4143 4144 assert(root->refcount == 0); 4145 4146 /* 4147 * Pass over the DAG removing unreferenced objects from 4148 * appropriate lists. 4149 */ 4150 unlink_object(root); 4151 4152 /* Unmap all objects that are no longer referenced. */ 4153 linkp = &obj_list->next; 4154 while ((obj = *linkp) != NULL) { 4155 if (obj->refcount == 0) { 4156 LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0, 4157 obj->path); 4158 dbg("unloading \"%s\"", obj->path); 4159 unload_filtees(root); 4160 munmap(obj->mapbase, obj->mapsize); 4161 linkmap_delete(obj); 4162 *linkp = obj->next; 4163 obj_count--; 4164 obj_free(obj); 4165 } else 4166 linkp = &obj->next; 4167 } 4168 obj_tail = linkp; 4169} 4170 4171static void 4172unlink_object(Obj_Entry *root) 4173{ 4174 Objlist_Entry *elm; 4175 4176 if (root->refcount == 0) { 4177 /* Remove the object from the RTLD_GLOBAL list. */ 4178 objlist_remove(&list_global, root); 4179 4180 /* Remove the object from all objects' DAG lists. */ 4181 STAILQ_FOREACH(elm, &root->dagmembers, link) { 4182 objlist_remove(&elm->obj->dldags, root); 4183 if (elm->obj != root) 4184 unlink_object(elm->obj); 4185 } 4186 } 4187} 4188 4189static void 4190ref_dag(Obj_Entry *root) 4191{ 4192 Objlist_Entry *elm; 4193 4194 assert(root->dag_inited); 4195 STAILQ_FOREACH(elm, &root->dagmembers, link) 4196 elm->obj->refcount++; 4197} 4198 4199static void 4200unref_dag(Obj_Entry *root) 4201{ 4202 Objlist_Entry *elm; 4203 4204 assert(root->dag_inited); 4205 STAILQ_FOREACH(elm, &root->dagmembers, link) 4206 elm->obj->refcount--; 4207} 4208 4209/* 4210 * Common code for MD __tls_get_addr(). 4211 */ 4212static void *tls_get_addr_slow(Elf_Addr **, int, size_t) __noinline; 4213static void * 4214tls_get_addr_slow(Elf_Addr **dtvp, int index, size_t offset) 4215{ 4216 Elf_Addr *newdtv, *dtv; 4217 RtldLockState lockstate; 4218 int to_copy; 4219 4220 dtv = *dtvp; 4221 /* Check dtv generation in case new modules have arrived */ 4222 if (dtv[0] != tls_dtv_generation) { 4223 wlock_acquire(rtld_bind_lock, &lockstate); 4224 newdtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4225 to_copy = dtv[1]; 4226 if (to_copy > tls_max_index) 4227 to_copy = tls_max_index; 4228 memcpy(&newdtv[2], &dtv[2], to_copy * sizeof(Elf_Addr)); 4229 newdtv[0] = tls_dtv_generation; 4230 newdtv[1] = tls_max_index; 4231 free(dtv); 4232 lock_release(rtld_bind_lock, &lockstate); 4233 dtv = *dtvp = newdtv; 4234 } 4235 4236 /* Dynamically allocate module TLS if necessary */ 4237 if (dtv[index + 1] == 0) { 4238 /* Signal safe, wlock will block out signals. */ 4239 wlock_acquire(rtld_bind_lock, &lockstate); 4240 if (!dtv[index + 1]) 4241 dtv[index + 1] = (Elf_Addr)allocate_module_tls(index); 4242 lock_release(rtld_bind_lock, &lockstate); 4243 } 4244 return ((void *)(dtv[index + 1] + offset)); 4245} 4246 4247void * 4248tls_get_addr_common(Elf_Addr **dtvp, int index, size_t offset) 4249{ 4250 Elf_Addr *dtv; 4251 4252 dtv = *dtvp; 4253 /* Check dtv generation in case new modules have arrived */ 4254 if (__predict_true(dtv[0] == tls_dtv_generation && 4255 dtv[index + 1] != 0)) 4256 return ((void *)(dtv[index + 1] + offset)); 4257 return (tls_get_addr_slow(dtvp, index, offset)); 4258} 4259 4260#if defined(__arm__) || defined(__ia64__) || defined(__mips__) || defined(__powerpc__) 4261 4262/* 4263 * Allocate Static TLS using the Variant I method. 4264 */ 4265void * 4266allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign) 4267{ 4268 Obj_Entry *obj; 4269 char *tcb; 4270 Elf_Addr **tls; 4271 Elf_Addr *dtv; 4272 Elf_Addr addr; 4273 int i; 4274 4275 if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE) 4276 return (oldtcb); 4277 4278 assert(tcbsize >= TLS_TCB_SIZE); 4279 tcb = xcalloc(1, tls_static_space - TLS_TCB_SIZE + tcbsize); 4280 tls = (Elf_Addr **)(tcb + tcbsize - TLS_TCB_SIZE); 4281 4282 if (oldtcb != NULL) { 4283 memcpy(tls, oldtcb, tls_static_space); 4284 free(oldtcb); 4285 4286 /* Adjust the DTV. */ 4287 dtv = tls[0]; 4288 for (i = 0; i < dtv[1]; i++) { 4289 if (dtv[i+2] >= (Elf_Addr)oldtcb && 4290 dtv[i+2] < (Elf_Addr)oldtcb + tls_static_space) { 4291 dtv[i+2] = dtv[i+2] - (Elf_Addr)oldtcb + (Elf_Addr)tls; 4292 } 4293 } 4294 } else { 4295 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4296 tls[0] = dtv; 4297 dtv[0] = tls_dtv_generation; 4298 dtv[1] = tls_max_index; 4299 4300 for (obj = objs; obj; obj = obj->next) { 4301 if (obj->tlsoffset > 0) { 4302 addr = (Elf_Addr)tls + obj->tlsoffset; 4303 if (obj->tlsinitsize > 0) 4304 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize); 4305 if (obj->tlssize > obj->tlsinitsize) 4306 memset((void*) (addr + obj->tlsinitsize), 0, 4307 obj->tlssize - obj->tlsinitsize); 4308 dtv[obj->tlsindex + 1] = addr; 4309 } 4310 } 4311 } 4312 4313 return (tcb); 4314} 4315 4316void 4317free_tls(void *tcb, size_t tcbsize, size_t tcbalign) 4318{ 4319 Elf_Addr *dtv; 4320 Elf_Addr tlsstart, tlsend; 4321 int dtvsize, i; 4322 4323 assert(tcbsize >= TLS_TCB_SIZE); 4324 4325 tlsstart = (Elf_Addr)tcb + tcbsize - TLS_TCB_SIZE; 4326 tlsend = tlsstart + tls_static_space; 4327 4328 dtv = *(Elf_Addr **)tlsstart; 4329 dtvsize = dtv[1]; 4330 for (i = 0; i < dtvsize; i++) { 4331 if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] >= tlsend)) { 4332 free((void*)dtv[i+2]); 4333 } 4334 } 4335 free(dtv); 4336 free(tcb); 4337} 4338 4339#endif 4340 4341#if defined(__i386__) || defined(__amd64__) || defined(__sparc64__) 4342 4343/* 4344 * Allocate Static TLS using the Variant II method. 4345 */ 4346void * 4347allocate_tls(Obj_Entry *objs, void *oldtls, size_t tcbsize, size_t tcbalign) 4348{ 4349 Obj_Entry *obj; 4350 size_t size, ralign; 4351 char *tls; 4352 Elf_Addr *dtv, *olddtv; 4353 Elf_Addr segbase, oldsegbase, addr; 4354 int i; 4355 4356 ralign = tcbalign; 4357 if (tls_static_max_align > ralign) 4358 ralign = tls_static_max_align; 4359 size = round(tls_static_space, ralign) + round(tcbsize, ralign); 4360 4361 assert(tcbsize >= 2*sizeof(Elf_Addr)); 4362 tls = malloc_aligned(size, ralign); 4363 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr)); 4364 4365 segbase = (Elf_Addr)(tls + round(tls_static_space, ralign)); 4366 ((Elf_Addr*)segbase)[0] = segbase; 4367 ((Elf_Addr*)segbase)[1] = (Elf_Addr) dtv; 4368 4369 dtv[0] = tls_dtv_generation; 4370 dtv[1] = tls_max_index; 4371 4372 if (oldtls) { 4373 /* 4374 * Copy the static TLS block over whole. 4375 */ 4376 oldsegbase = (Elf_Addr) oldtls; 4377 memcpy((void *)(segbase - tls_static_space), 4378 (const void *)(oldsegbase - tls_static_space), 4379 tls_static_space); 4380 4381 /* 4382 * If any dynamic TLS blocks have been created tls_get_addr(), 4383 * move them over. 4384 */ 4385 olddtv = ((Elf_Addr**)oldsegbase)[1]; 4386 for (i = 0; i < olddtv[1]; i++) { 4387 if (olddtv[i+2] < oldsegbase - size || olddtv[i+2] > oldsegbase) { 4388 dtv[i+2] = olddtv[i+2]; 4389 olddtv[i+2] = 0; 4390 } 4391 } 4392 4393 /* 4394 * We assume that this block was the one we created with 4395 * allocate_initial_tls(). 4396 */ 4397 free_tls(oldtls, 2*sizeof(Elf_Addr), sizeof(Elf_Addr)); 4398 } else { 4399 for (obj = objs; obj; obj = obj->next) { 4400 if (obj->tlsoffset) { 4401 addr = segbase - obj->tlsoffset; 4402 memset((void*) (addr + obj->tlsinitsize), 4403 0, obj->tlssize - obj->tlsinitsize); 4404 if (obj->tlsinit) 4405 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize); 4406 dtv[obj->tlsindex + 1] = addr; 4407 } 4408 } 4409 } 4410 4411 return (void*) segbase; 4412} 4413 4414void 4415free_tls(void *tls, size_t tcbsize, size_t tcbalign) 4416{ 4417 Elf_Addr* dtv; 4418 size_t size, ralign; 4419 int dtvsize, i; 4420 Elf_Addr tlsstart, tlsend; 4421 4422 /* 4423 * Figure out the size of the initial TLS block so that we can 4424 * find stuff which ___tls_get_addr() allocated dynamically. 4425 */ 4426 ralign = tcbalign; 4427 if (tls_static_max_align > ralign) 4428 ralign = tls_static_max_align; 4429 size = round(tls_static_space, ralign); 4430 4431 dtv = ((Elf_Addr**)tls)[1]; 4432 dtvsize = dtv[1]; 4433 tlsend = (Elf_Addr) tls; 4434 tlsstart = tlsend - size; 4435 for (i = 0; i < dtvsize; i++) { 4436 if (dtv[i + 2] != 0 && (dtv[i + 2] < tlsstart || dtv[i + 2] > tlsend)) { 4437 free_aligned((void *)dtv[i + 2]); 4438 } 4439 } 4440 4441 free_aligned((void *)tlsstart); 4442 free((void*) dtv); 4443} 4444 4445#endif 4446 4447/* 4448 * Allocate TLS block for module with given index. 4449 */ 4450void * 4451allocate_module_tls(int index) 4452{ 4453 Obj_Entry* obj; 4454 char* p; 4455 4456 for (obj = obj_list; obj; obj = obj->next) { 4457 if (obj->tlsindex == index) 4458 break; 4459 } 4460 if (!obj) { 4461 _rtld_error("Can't find module with TLS index %d", index); 4462 die(); 4463 } 4464 4465 p = malloc_aligned(obj->tlssize, obj->tlsalign); 4466 memcpy(p, obj->tlsinit, obj->tlsinitsize); 4467 memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize); 4468 4469 return p; 4470} 4471 4472bool 4473allocate_tls_offset(Obj_Entry *obj) 4474{ 4475 size_t off; 4476 4477 if (obj->tls_done) 4478 return true; 4479 4480 if (obj->tlssize == 0) { 4481 obj->tls_done = true; 4482 return true; 4483 } 4484 4485 if (obj->tlsindex == 1) 4486 off = calculate_first_tls_offset(obj->tlssize, obj->tlsalign); 4487 else 4488 off = calculate_tls_offset(tls_last_offset, tls_last_size, 4489 obj->tlssize, obj->tlsalign); 4490 4491 /* 4492 * If we have already fixed the size of the static TLS block, we 4493 * must stay within that size. When allocating the static TLS, we 4494 * leave a small amount of space spare to be used for dynamically 4495 * loading modules which use static TLS. 4496 */ 4497 if (tls_static_space != 0) { 4498 if (calculate_tls_end(off, obj->tlssize) > tls_static_space) 4499 return false; 4500 } else if (obj->tlsalign > tls_static_max_align) { 4501 tls_static_max_align = obj->tlsalign; 4502 } 4503 4504 tls_last_offset = obj->tlsoffset = off; 4505 tls_last_size = obj->tlssize; 4506 obj->tls_done = true; 4507 4508 return true; 4509} 4510 4511void 4512free_tls_offset(Obj_Entry *obj) 4513{ 4514 4515 /* 4516 * If we were the last thing to allocate out of the static TLS 4517 * block, we give our space back to the 'allocator'. This is a 4518 * simplistic workaround to allow libGL.so.1 to be loaded and 4519 * unloaded multiple times. 4520 */ 4521 if (calculate_tls_end(obj->tlsoffset, obj->tlssize) 4522 == calculate_tls_end(tls_last_offset, tls_last_size)) { 4523 tls_last_offset -= obj->tlssize; 4524 tls_last_size = 0; 4525 } 4526} 4527 4528void * 4529_rtld_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign) 4530{ 4531 void *ret; 4532 RtldLockState lockstate; 4533 4534 wlock_acquire(rtld_bind_lock, &lockstate); 4535 ret = allocate_tls(obj_list, oldtls, tcbsize, tcbalign); 4536 lock_release(rtld_bind_lock, &lockstate); 4537 return (ret); 4538} 4539 4540void 4541_rtld_free_tls(void *tcb, size_t tcbsize, size_t tcbalign) 4542{ 4543 RtldLockState lockstate; 4544 4545 wlock_acquire(rtld_bind_lock, &lockstate); 4546 free_tls(tcb, tcbsize, tcbalign); 4547 lock_release(rtld_bind_lock, &lockstate); 4548} 4549 4550static void 4551object_add_name(Obj_Entry *obj, const char *name) 4552{ 4553 Name_Entry *entry; 4554 size_t len; 4555 4556 len = strlen(name); 4557 entry = malloc(sizeof(Name_Entry) + len); 4558 4559 if (entry != NULL) { 4560 strcpy(entry->name, name); 4561 STAILQ_INSERT_TAIL(&obj->names, entry, link); 4562 } 4563} 4564 4565static int 4566object_match_name(const Obj_Entry *obj, const char *name) 4567{ 4568 Name_Entry *entry; 4569 4570 STAILQ_FOREACH(entry, &obj->names, link) { 4571 if (strcmp(name, entry->name) == 0) 4572 return (1); 4573 } 4574 return (0); 4575} 4576 4577static Obj_Entry * 4578locate_dependency(const Obj_Entry *obj, const char *name) 4579{ 4580 const Objlist_Entry *entry; 4581 const Needed_Entry *needed; 4582 4583 STAILQ_FOREACH(entry, &list_main, link) { 4584 if (object_match_name(entry->obj, name)) 4585 return entry->obj; 4586 } 4587 4588 for (needed = obj->needed; needed != NULL; needed = needed->next) { 4589 if (strcmp(obj->strtab + needed->name, name) == 0 || 4590 (needed->obj != NULL && object_match_name(needed->obj, name))) { 4591 /* 4592 * If there is DT_NEEDED for the name we are looking for, 4593 * we are all set. Note that object might not be found if 4594 * dependency was not loaded yet, so the function can 4595 * return NULL here. This is expected and handled 4596 * properly by the caller. 4597 */ 4598 return (needed->obj); 4599 } 4600 } 4601 _rtld_error("%s: Unexpected inconsistency: dependency %s not found", 4602 obj->path, name); 4603 die(); 4604} 4605 4606static int 4607check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj, 4608 const Elf_Vernaux *vna) 4609{ 4610 const Elf_Verdef *vd; 4611 const char *vername; 4612 4613 vername = refobj->strtab + vna->vna_name; 4614 vd = depobj->verdef; 4615 if (vd == NULL) { 4616 _rtld_error("%s: version %s required by %s not defined", 4617 depobj->path, vername, refobj->path); 4618 return (-1); 4619 } 4620 for (;;) { 4621 if (vd->vd_version != VER_DEF_CURRENT) { 4622 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 4623 depobj->path, vd->vd_version); 4624 return (-1); 4625 } 4626 if (vna->vna_hash == vd->vd_hash) { 4627 const Elf_Verdaux *aux = (const Elf_Verdaux *) 4628 ((char *)vd + vd->vd_aux); 4629 if (strcmp(vername, depobj->strtab + aux->vda_name) == 0) 4630 return (0); 4631 } 4632 if (vd->vd_next == 0) 4633 break; 4634 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next); 4635 } 4636 if (vna->vna_flags & VER_FLG_WEAK) 4637 return (0); 4638 _rtld_error("%s: version %s required by %s not found", 4639 depobj->path, vername, refobj->path); 4640 return (-1); 4641} 4642 4643static int 4644rtld_verify_object_versions(Obj_Entry *obj) 4645{ 4646 const Elf_Verneed *vn; 4647 const Elf_Verdef *vd; 4648 const Elf_Verdaux *vda; 4649 const Elf_Vernaux *vna; 4650 const Obj_Entry *depobj; 4651 int maxvernum, vernum; 4652 4653 if (obj->ver_checked) 4654 return (0); 4655 obj->ver_checked = true; 4656 4657 maxvernum = 0; 4658 /* 4659 * Walk over defined and required version records and figure out 4660 * max index used by any of them. Do very basic sanity checking 4661 * while there. 4662 */ 4663 vn = obj->verneed; 4664 while (vn != NULL) { 4665 if (vn->vn_version != VER_NEED_CURRENT) { 4666 _rtld_error("%s: Unsupported version %d of Elf_Verneed entry", 4667 obj->path, vn->vn_version); 4668 return (-1); 4669 } 4670 vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux); 4671 for (;;) { 4672 vernum = VER_NEED_IDX(vna->vna_other); 4673 if (vernum > maxvernum) 4674 maxvernum = vernum; 4675 if (vna->vna_next == 0) 4676 break; 4677 vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next); 4678 } 4679 if (vn->vn_next == 0) 4680 break; 4681 vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next); 4682 } 4683 4684 vd = obj->verdef; 4685 while (vd != NULL) { 4686 if (vd->vd_version != VER_DEF_CURRENT) { 4687 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry", 4688 obj->path, vd->vd_version); 4689 return (-1); 4690 } 4691 vernum = VER_DEF_IDX(vd->vd_ndx); 4692 if (vernum > maxvernum) 4693 maxvernum = vernum; 4694 if (vd->vd_next == 0) 4695 break; 4696 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next); 4697 } 4698 4699 if (maxvernum == 0) 4700 return (0); 4701 4702 /* 4703 * Store version information in array indexable by version index. 4704 * Verify that object version requirements are satisfied along the 4705 * way. 4706 */ 4707 obj->vernum = maxvernum + 1; 4708 obj->vertab = xcalloc(obj->vernum, sizeof(Ver_Entry)); 4709 4710 vd = obj->verdef; 4711 while (vd != NULL) { 4712 if ((vd->vd_flags & VER_FLG_BASE) == 0) { 4713 vernum = VER_DEF_IDX(vd->vd_ndx); 4714 assert(vernum <= maxvernum); 4715 vda = (const Elf_Verdaux *)((char *)vd + vd->vd_aux); 4716 obj->vertab[vernum].hash = vd->vd_hash; 4717 obj->vertab[vernum].name = obj->strtab + vda->vda_name; 4718 obj->vertab[vernum].file = NULL; 4719 obj->vertab[vernum].flags = 0; 4720 } 4721 if (vd->vd_next == 0) 4722 break; 4723 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next); 4724 } 4725 4726 vn = obj->verneed; 4727 while (vn != NULL) { 4728 depobj = locate_dependency(obj, obj->strtab + vn->vn_file); 4729 if (depobj == NULL) 4730 return (-1); 4731 vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux); 4732 for (;;) { 4733 if (check_object_provided_version(obj, depobj, vna)) 4734 return (-1); 4735 vernum = VER_NEED_IDX(vna->vna_other); 4736 assert(vernum <= maxvernum); 4737 obj->vertab[vernum].hash = vna->vna_hash; 4738 obj->vertab[vernum].name = obj->strtab + vna->vna_name; 4739 obj->vertab[vernum].file = obj->strtab + vn->vn_file; 4740 obj->vertab[vernum].flags = (vna->vna_other & VER_NEED_HIDDEN) ? 4741 VER_INFO_HIDDEN : 0; 4742 if (vna->vna_next == 0) 4743 break; 4744 vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next); 4745 } 4746 if (vn->vn_next == 0) 4747 break; 4748 vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next); 4749 } 4750 return 0; 4751} 4752 4753static int 4754rtld_verify_versions(const Objlist *objlist) 4755{ 4756 Objlist_Entry *entry; 4757 int rc; 4758 4759 rc = 0; 4760 STAILQ_FOREACH(entry, objlist, link) { 4761 /* 4762 * Skip dummy objects or objects that have their version requirements 4763 * already checked. 4764 */ 4765 if (entry->obj->strtab == NULL || entry->obj->vertab != NULL) 4766 continue; 4767 if (rtld_verify_object_versions(entry->obj) == -1) { 4768 rc = -1; 4769 if (ld_tracing == NULL) 4770 break; 4771 } 4772 } 4773 if (rc == 0 || ld_tracing != NULL) 4774 rc = rtld_verify_object_versions(&obj_rtld); 4775 return rc; 4776} 4777 4778const Ver_Entry * 4779fetch_ventry(const Obj_Entry *obj, unsigned long symnum) 4780{ 4781 Elf_Versym vernum; 4782 4783 if (obj->vertab) { 4784 vernum = VER_NDX(obj->versyms[symnum]); 4785 if (vernum >= obj->vernum) { 4786 _rtld_error("%s: symbol %s has wrong verneed value %d", 4787 obj->path, obj->strtab + symnum, vernum); 4788 } else if (obj->vertab[vernum].hash != 0) { 4789 return &obj->vertab[vernum]; 4790 } 4791 } 4792 return NULL; 4793} 4794 4795int 4796_rtld_get_stack_prot(void) 4797{ 4798 4799 return (stack_prot); 4800} 4801 4802int 4803_rtld_is_dlopened(void *arg) 4804{ 4805 Obj_Entry *obj; 4806 RtldLockState lockstate; 4807 int res; 4808 4809 rlock_acquire(rtld_bind_lock, &lockstate); 4810 obj = dlcheck(arg); 4811 if (obj == NULL) 4812 obj = obj_from_addr(arg); 4813 if (obj == NULL) { 4814 _rtld_error("No shared object contains address"); 4815 lock_release(rtld_bind_lock, &lockstate); 4816 return (-1); 4817 } 4818 res = obj->dlopened ? 1 : 0; 4819 lock_release(rtld_bind_lock, &lockstate); 4820 return (res); 4821} 4822 4823static void 4824map_stacks_exec(RtldLockState *lockstate) 4825{ 4826 void (*thr_map_stacks_exec)(void); 4827 4828 if ((max_stack_flags & PF_X) == 0 || (stack_prot & PROT_EXEC) != 0) 4829 return; 4830 thr_map_stacks_exec = (void (*)(void))(uintptr_t) 4831 get_program_var_addr("__pthread_map_stacks_exec", lockstate); 4832 if (thr_map_stacks_exec != NULL) { 4833 stack_prot |= PROT_EXEC; 4834 thr_map_stacks_exec(); 4835 } 4836} 4837 4838void 4839symlook_init(SymLook *dst, const char *name) 4840{ 4841 4842 bzero(dst, sizeof(*dst)); 4843 dst->name = name; 4844 dst->hash = elf_hash(name); 4845 dst->hash_gnu = gnu_hash(name); 4846} 4847 4848static void 4849symlook_init_from_req(SymLook *dst, const SymLook *src) 4850{ 4851 4852 dst->name = src->name; 4853 dst->hash = src->hash; 4854 dst->hash_gnu = src->hash_gnu; 4855 dst->ventry = src->ventry; 4856 dst->flags = src->flags; 4857 dst->defobj_out = NULL; 4858 dst->sym_out = NULL; 4859 dst->lockstate = src->lockstate; 4860} 4861 4862/* 4863 * Overrides for libc_pic-provided functions. 4864 */ 4865 4866int 4867__getosreldate(void) 4868{ 4869 size_t len; 4870 int oid[2]; 4871 int error, osrel; 4872 4873 if (osreldate != 0) 4874 return (osreldate); 4875 4876 oid[0] = CTL_KERN; 4877 oid[1] = KERN_OSRELDATE; 4878 osrel = 0; 4879 len = sizeof(osrel); 4880 error = sysctl(oid, 2, &osrel, &len, NULL, 0); 4881 if (error == 0 && osrel > 0 && len == sizeof(osrel)) 4882 osreldate = osrel; 4883 return (osreldate); 4884} 4885 4886void 4887exit(int status) 4888{ 4889 4890 _exit(status); 4891} 4892 4893void (*__cleanup)(void); 4894int __isthreaded = 0; 4895int _thread_autoinit_dummy_decl = 1; 4896 4897/* 4898 * No unresolved symbols for rtld. 4899 */ 4900void 4901__pthread_cxa_finalize(struct dl_phdr_info *a) 4902{ 4903} 4904 4905void 4906__stack_chk_fail(void) 4907{ 4908 4909 _rtld_error("stack overflow detected; terminated"); 4910 die(); 4911} 4912__weak_reference(__stack_chk_fail, __stack_chk_fail_local); 4913 4914void 4915__chk_fail(void) 4916{ 4917 4918 _rtld_error("buffer overflow detected; terminated"); 4919 die(); 4920} 4921 4922const char * 4923rtld_strerror(int errnum) 4924{ 4925 4926 if (errnum < 0 || errnum >= sys_nerr) 4927 return ("Unknown error"); 4928 return (sys_errlist[errnum]); 4929} 4930