ldso/ldso/ldso.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Program to load an ELF binary on a linux system, and run it
   4  * after resolving ELF shared library symbols
   5  *
   6  * Copyright (C) 2005 by Joakim Tjernlund
   7  * Copyright (C) 2000-2006 by Erik Andersen <andersen@codepoet.org>
   8  * Copyright (c) 1994-2000 Eric Youngdale, Peter MacDonald,
   9  *                              David Engel, Hongjiu Lu and Mitch D'Souza
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions and the following disclaimer.
  16  * 2. The name of the above contributors may not be
  17  *    used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33 #include "ldso.h"
  34 #include "unsecvars.h"
  35
  36 /* Pull in common debug code */
  37 #include "dl-debug.c"
  38
  39 #define ALLOW_ZERO_PLTGOT
  40
  41 #if defined(USE_TLS) && USE_TLS
  42 #include "dl-tls.c"
  43 #endif
  44
  45 /* Pull in the value of _dl_progname */
  46 #include LDSO_ELFINTERP
  47
  48 /* Global variables used within the shared library loader */
  49 #ifdef __LDSO_LD_LIBRARY_PATH__
  50 char *_dl_library_path         = NULL;  /* Where we look for libraries */
  51 #endif
  52 #ifdef __LDSO_PRELOAD_ENV_SUPPORT__
  53 char *_dl_preload              = NULL;  /* Things to be loaded before the libs */
  54 #endif
  55 int _dl_errno                  = 0;     /* We can't use the real errno in ldso */
  56 size_t _dl_pagesize            = 0;     /* Store the page size for use later */
  57 struct r_debug *_dl_debug_addr = NULL;  /* Used to communicate with the gdb debugger */
  58 void *(*_dl_malloc_function) (size_t size) = NULL;
  59 void (*_dl_free_function) (void *p) = NULL;
  60
  61 #ifdef __LDSO_PRELINK_SUPPORT__
  62 char *_dl_trace_prelink                      = NULL;    /* Library for prelinking trace */
  63 struct elf_resolve *_dl_trace_prelink_map    = NULL;    /* Library module for prelinking trace */
  64 bool _dl_verbose                                = true;                                 /* On by default */
  65 bool prelinked                                  = false;
  66 #endif
  67 static int _dl_secure = 1; /* Are we dealing with setuid stuff? */
  68
  69 #ifdef __SUPPORT_LD_DEBUG__
  70 char *_dl_debug           = NULL;
  71 char *_dl_debug_symbols   = NULL;
  72 char *_dl_debug_move      = NULL;
  73 char *_dl_debug_reloc     = NULL;
  74 char *_dl_debug_detail    = NULL;
  75 char *_dl_debug_nofixups  = NULL;
  76 char *_dl_debug_bindings  = NULL;
  77 int   _dl_debug_file      = 2;
  78 #endif
  79
  80 #ifdef __DSBT__
  81 void **_dl_ldso_dsbt = NULL;
  82 #endif
  83
  84 unsigned long attribute_hidden _dl_skip_args = 0;
  85
  86 const char *_dl_progname = UCLIBC_LDSO;      /* The name of the executable being run */
  87 #include "dl-startup.c"
  88 #include "dl-symbols.c"
  89 #include "dl-array.c"
  90
  91 /*
  92  * This stub function is used by some debuggers.  The idea is that they
  93  * can set an internal breakpoint on it, so that we are notified when the
  94  * address mapping is changed in some way.
  95  */
  96 void _dl_debug_state(void);
  97 rtld_hidden_proto(_dl_debug_state, noinline);
  98 void _dl_debug_state(void)
  99 {
 100         /* Make sure GCC doesn't recognize this function as pure, to avoid
 101          * having the calls optimized away.
 102          */
 103         __asm__("");
 104 }
 105 rtld_hidden_def(_dl_debug_state);
 106
 107 static unsigned char *_dl_malloc_addr = NULL;   /* Lets _dl_malloc use the already allocated memory page */
 108 static unsigned char *_dl_mmap_zero   = NULL;   /* Also used by _dl_malloc */
 109
 110 static struct elf_resolve **init_fini_list;
 111 static struct elf_resolve **scope_elem_list;
 112 static unsigned int nlist; /* # items in init_fini_list */
 113 extern void _start(void);
 114
 115 #ifdef __UCLIBC_HAS_SSP__
 116 # include <dl-osinfo.h>
 117 static uintptr_t stack_chk_guard;
 118 # ifndef THREAD_SET_STACK_GUARD
 119 /* Only exported for architectures that don't store the stack guard canary
 120  * in local thread area.  */
 121 uintptr_t __stack_chk_guard attribute_relro;
 122 # endif
 123 # ifdef __UCLIBC_HAS_SSP_COMPAT__
 124 uintptr_t __guard attribute_relro;
 125 # endif
 126 #endif
 127
 128 #ifdef __LDSO_SEARCH_INTERP_PATH__
 129 const char *_dl_ldsopath = NULL;        /* Location of the shared lib loader */
 130
 131 static void _dl_ldsopath_init(struct elf_resolve *tpnt)
 132 {
 133         char *ldsopath, *ptmp;
 134
 135         /*
 136          * Store the path where the shared lib loader was found for later use.
 137          * Note that this logic isn't bullet proof when it comes to relative
 138          * paths: if you use "./lib/ldso.so", and then the app does chdir()
 139          * followed by dlopen(), the old ldso path won't get searched.  But
 140          * that is a fairly pathological use case, so if you don't like that,
 141          * then set a full path to your interp and be done :P.
 142          */
 143         ldsopath = _dl_strdup(tpnt->libname);
 144         ptmp = _dl_strrchr(ldsopath, '/');
 145         /*
 146          * If there is no "/", then set the path to "", and the code
 147          * later on will take this to implicitly mean "search $PWD".
 148          */
 149         if (!ptmp)
 150                 ptmp = ldsopath;
 151         *ptmp = '\0';
 152
 153         _dl_ldsopath = ldsopath;
 154         _dl_debug_early("Lib Loader: (%x) %s: using path: %s\n",
 155                 (unsigned) DL_LOADADDR_BASE(tpnt->loadaddr), tpnt->libname,
 156                 _dl_ldsopath);
 157 }
 158 #else
 159 #define _dl_ldsopath_init(tpnt)
 160 #endif
 161
 162 char *_dl_getenv(const char *symbol, char **envp)
 163 {
 164         char *pnt;
 165         const char *pnt1;
 166
 167         while ((pnt = *envp++)) {
 168                 pnt1 = symbol;
 169                 while (*pnt && *pnt == *pnt1)
 170                         pnt1++, pnt++;
 171                 if (!*pnt || *pnt != '=' || *pnt1)
 172                         continue;
 173                 return pnt + 1;
 174         }
 175         return 0;
 176 }
 177
 178 void _dl_unsetenv(const char *symbol, char **envp)
 179 {
 180         char *pnt;
 181         const char *pnt1;
 182         char **newenvp = envp;
 183
 184         for (pnt = *envp; pnt; pnt = *++envp) {
 185                 pnt1 = symbol;
 186                 while (*pnt && *pnt == *pnt1)
 187                         pnt1++, pnt++;
 188                 if (!*pnt || *pnt != '=' || *pnt1)
 189                         *newenvp++ = *envp;
 190         }
 191         *newenvp++ = *envp;
 192         return;
 193 }
 194
 195 static int _dl_suid_ok(void)
 196 {
 197         __kernel_uid_t uid, euid;
 198         __kernel_gid_t gid, egid;
 199
 200         uid = _dl_getuid();
 201         euid = _dl_geteuid();
 202         gid = _dl_getgid();
 203         egid = _dl_getegid();
 204
 205         if (uid == euid && gid == egid) {
 206                 return 1;
 207         }
 208         return 0;
 209 }
 210
 211 void *_dl_malloc(size_t size)
 212 {
 213         void *retval;
 214
 215 #if 0
 216         _dl_debug_early("request for %d bytes\n", size);
 217 #endif
 218
 219         if (_dl_malloc_function)
 220                 return (*_dl_malloc_function) (size);
 221
 222         if (_dl_malloc_addr - _dl_mmap_zero + size > _dl_pagesize) {
 223                 size_t rounded_size;
 224
 225                 /* Since the above assumes we get a full page even if
 226                    we request less than that, make sure we request a
 227                    full page, since uClinux may give us less than than
 228                    a full page.  We might round even
 229                    larger-than-a-page sizes, but we end up never
 230                    reusing _dl_mmap_zero/_dl_malloc_addr in that case,
 231                    so we don't do it.
 232
 233                    The actual page size doesn't really matter; as long
 234                    as we're self-consistent here, we're safe.  */
 235                 if (size < _dl_pagesize)
 236                         rounded_size = (size + ADDR_ALIGN) & _dl_pagesize;
 237                 else
 238                         rounded_size = size;
 239
 240                 _dl_debug_early("mmapping more memory\n");
 241                 _dl_mmap_zero = _dl_malloc_addr = _dl_mmap((void *) 0, rounded_size,
 242                                 PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_UNINITIALIZE, -1, 0);
 243                 if (_dl_mmap_check_error(_dl_mmap_zero)) {
 244                         _dl_dprintf(2, "%s: mmap of a spare page failed!\n", _dl_progname);
 245                         _dl_exit(20);
 246                 }
 247         }
 248         retval = _dl_malloc_addr;
 249         _dl_malloc_addr += size;
 250
 251         /*
 252          * Align memory to DL_MALLOC_ALIGN byte boundary.  Some
 253          * platforms require this, others simply get better
 254          * performance.
 255          */
 256         _dl_malloc_addr = (unsigned char *) (((unsigned long) _dl_malloc_addr + DL_MALLOC_ALIGN - 1) & ~(DL_MALLOC_ALIGN - 1));
 257         return retval;
 258 }
 259
 260 static void *_dl_zalloc(size_t size)
 261 {
 262         void *p = _dl_malloc(size);
 263         if (p)
 264                 _dl_memset(p, 0, size);
 265         return p;
 266 }
 267
 268 void _dl_free(void *p)
 269 {
 270         if (_dl_free_function)
 271                 (*_dl_free_function) (p);
 272 }
 273
 274 #if defined(USE_TLS) && USE_TLS
 275 void *_dl_memalign(size_t __boundary, size_t __size)
 276 {
 277         void *result;
 278         int i = 0;
 279         size_t delta;
 280         size_t rounded = 0;
 281
 282         if (_dl_memalign_function)
 283                 return (*_dl_memalign_function) (__boundary, __size);
 284
 285         while (rounded < __boundary) {
 286                 rounded = (1 << i++);
 287         }
 288
 289         delta = (((size_t) _dl_malloc_addr + __size) & (rounded - 1));
 290
 291         if ((result = _dl_malloc(rounded - delta)) == NULL)
 292                 return result;
 293
 294         result = _dl_malloc(__size);
 295
 296         return result;
 297 }
 298 #endif
 299
 300 static void __attribute__ ((destructor)) __attribute_used__ _dl_fini(void)
 301 {
 302         unsigned int i;
 303         struct elf_resolve * tpnt;
 304
 305         for (i = 0; i < nlist; ++i) {
 306                 tpnt = init_fini_list[i];
 307                 if (tpnt->init_flag & FINI_FUNCS_CALLED)
 308                         continue;
 309                 tpnt->init_flag |= FINI_FUNCS_CALLED;
 310                 _dl_run_fini_array(tpnt);
 311                 if (tpnt->dynamic_info[DT_FINI]) {
 312                         void (*dl_elf_func) (void);
 313
 314                         dl_elf_func = (void (*)(void)) (intptr_t) DL_RELOC_ADDR(tpnt->loadaddr, tpnt->dynamic_info[DT_FINI]);
 315                         _dl_if_debug_dprint("\ncalling FINI: %s\n\n", tpnt->libname);
 316                         DL_CALL_FUNC_AT_ADDR (dl_elf_func, tpnt->loadaddr, (void(*)(void)));
 317                 }
 318         }
 319 }
 320
 321 #ifdef __LDSO_PRELINK_SUPPORT__
 322 static void trace_objects(struct elf_resolve *tpnt, char *str_name)
 323 {
 324         if (_dl_strcmp(_dl_trace_prelink, tpnt->libname) == 0)
 325                 _dl_trace_prelink_map = tpnt;
 326         if (tpnt->libtype == elf_executable) {
 327 /* Main executeble */
 328                 _dl_dprintf(1, "\t%s => %s (%x, %x)", tpnt->libname, tpnt->libname,
 329                                         tpnt->mapaddr, DL_LOADADDR_BASE(tpnt->loadaddr));
 330         } else {
 331 /* Preloaded, Needed or interpreter */
 332                 _dl_dprintf(1, "\t%s => %s (%x, %x)", str_name, tpnt->libname,
 333                                         tpnt->mapaddr, DL_LOADADDR_BASE(tpnt->loadaddr));
 334         }
 335
 336 #if defined USE_TLS && USE_TLS
 337         if ((tpnt->libtype != program_interpreter) && (tpnt->l_tls_modid))
 338                 _dl_dprintf (1, " TLS(%x, %x)\n", tpnt->l_tls_modid,
 339                                         (size_t) tpnt->l_tls_offset);
 340         else
 341 #endif
 342                 _dl_dprintf (1, "\n");
 343 }
 344 #endif
 345
 346 static struct elf_resolve * add_ldso(struct elf_resolve *tpnt,
 347                                                                          DL_LOADADDR_TYPE load_addr,
 348                                                                          ElfW(Addr) ldso_mapaddr,
 349                                                                          ElfW(auxv_t) auxvt[AT_EGID + 1],
 350                                                                          struct dyn_elf *rpnt)
 351 {
 352                 ElfW(Ehdr) *epnt = (ElfW(Ehdr) *) auxvt[AT_BASE].a_un.a_val;
 353                 ElfW(Phdr) *myppnt = (ElfW(Phdr) *)
 354                                 DL_RELOC_ADDR(DL_GET_RUN_ADDR(load_addr, ldso_mapaddr),
 355                                                           epnt->e_phoff);
 356                 int j;
 357                 struct stat st;
 358
 359                 tpnt = _dl_add_elf_hash_table(tpnt->libname, tpnt->loadaddr,
 360                                               tpnt->dynamic_info, (unsigned long)tpnt->dynamic_addr,
 361                                               0);
 362
 363                 tpnt->mapaddr = ldso_mapaddr;
 364                 if (_dl_stat(tpnt->libname, &st) >= 0) {
 365                         tpnt->st_dev = st.st_dev;
 366                         tpnt->st_ino = st.st_ino;
 367                 }
 368                 tpnt->n_phent = epnt->e_phnum;
 369                 tpnt->ppnt = myppnt;
 370                 for (j = 0; j < epnt->e_phnum; j++, myppnt++) {
 371                         if (myppnt->p_type ==  PT_GNU_RELRO) {
 372                                 tpnt->relro_addr = myppnt->p_vaddr;
 373                                 tpnt->relro_size = myppnt->p_memsz;
 374                                 break;
 375                         }
 376                 }
 377                 tpnt->libtype = program_interpreter;
 378                 if (rpnt) {
 379                         rpnt->next = _dl_zalloc(sizeof(struct dyn_elf));
 380                         rpnt->next->prev = rpnt;
 381                         rpnt = rpnt->next;
 382                 } else {
 383                         rpnt = _dl_zalloc(sizeof(struct dyn_elf));
 384                 }
 385                 rpnt->dyn = tpnt;
 386                 tpnt->rtld_flags = RTLD_NOW | RTLD_GLOBAL; /* Must not be LAZY */
 387
 388         return tpnt;
 389 }
 390
 391 static ptrdiff_t _dl_build_local_scope (struct elf_resolve **list,
 392                                                                                 struct elf_resolve *map)
 393 {
 394         struct elf_resolve **p = list;
 395         struct init_fini_list *q;
 396
 397         *p++ = map;
 398         map->init_flag |= DL_RESERVED;
 399         if (map->init_fini)
 400                 for (q = map->init_fini; q; q = q->next)
 401                         if (! (q->tpnt->init_flag & DL_RESERVED))
 402                                 p += _dl_build_local_scope (p, q->tpnt);
 403         return p - list;
 404 }
 405
 406 void *_dl_get_ready_to_run(struct elf_resolve *tpnt, DL_LOADADDR_TYPE load_addr,
 407                           ElfW(auxv_t) auxvt[AT_EGID + 1], char **envp, char **argv
 408                           DL_GET_READY_TO_RUN_EXTRA_PARMS)
 409 {
 410         ElfW(Addr) app_mapaddr = 0, ldso_mapaddr = 0;
 411         ElfW(Phdr) *ppnt;
 412         ElfW(Dyn) *dpnt;
 413         char *lpntstr;
 414         unsigned int i, cnt, nscope_elem;
 415         int unlazy = 0, trace_loaded_objects = 0;
 416         struct dyn_elf *rpnt;
 417         struct elf_resolve *tcurr;
 418         struct elf_resolve *tpnt1;
 419         struct elf_resolve *ldso_tpnt = NULL;
 420         struct elf_resolve app_tpnt_tmp;
 421         struct elf_resolve *app_tpnt = &app_tpnt_tmp;
 422         struct r_debug *debug_addr;
 423         unsigned long *lpnt;
 424         unsigned long *_dl_envp;                /* The environment address */
 425         ElfW(Addr) relro_addr = 0;
 426         size_t relro_size = 0;
 427         struct r_scope_elem *global_scope;
 428         struct elf_resolve **local_scope;
 429
 430 #if defined(USE_TLS) && USE_TLS
 431         void *tcbp = NULL;
 432 #endif
 433
 434         /* Wahoo!!! We managed to make a function call!  Get malloc
 435          * setup so we can use _dl_dprintf() to print debug noise
 436          * instead of the SEND_STDERR macros used in dl-startup.c */
 437
 438         _dl_memset(app_tpnt, 0, sizeof(*app_tpnt));
 439
 440         /* Store the page size for later use */
 441         _dl_pagesize = (auxvt[AT_PAGESZ].a_un.a_val) ? (size_t) auxvt[AT_PAGESZ].a_un.a_val : PAGE_SIZE;
 442         /* Make it so _dl_malloc can use the page of memory we have already
 443          * allocated.  We shouldn't need to grab any more memory.  This must
 444          * be first since things like _dl_dprintf() use _dl_malloc()...
 445          */
 446         _dl_malloc_addr = (unsigned char *)_dl_pagesize;
 447         _dl_mmap_zero = 0;
 448
 449         /* Wahoo!!! */
 450         _dl_debug_early("Cool, ldso survived making function calls\n");
 451
 452         /* Now we have done the mandatory linking of some things.  We are now
 453          * free to start using global variables, since these things have all
 454          * been fixed up by now.  Still no function calls outside of this
 455          * library, since the dynamic resolver is not yet ready.
 456          */
 457         if (argv[0]) {
 458                 _dl_progname = argv[0];
 459         }
 460
 461 #ifdef __DSBT__
 462         _dl_ldso_dsbt = (void *)tpnt->dynamic_info[DT_DSBT_BASE_IDX];
 463         _dl_ldso_dsbt[tpnt->dynamic_info[DT_DSBT_INDEX_IDX]] = _dl_ldso_dsbt;
 464 #endif
 465
 466 #ifndef __LDSO_STANDALONE_SUPPORT__
 467         if (_start == (void *) auxvt[AT_ENTRY].a_un.a_val) {
 468                 _dl_dprintf(2, "Standalone execution is not enabled\n");
 469                 _dl_exit(1);
 470         }
 471 #endif
 472
 473         /* Start to build the tables of the modules that are required for
 474          * this beast to run.  We start with the basic executable, and then
 475          * go from there.  Eventually we will run across ourself, and we
 476          * will need to properly deal with that as well.
 477          */
 478         rpnt = NULL;
 479         if (_dl_getenv("LD_BIND_NOW", envp))
 480                 unlazy = RTLD_NOW;
 481
 482         /* Now we need to figure out what kind of options are selected.
 483          * Note that for SUID programs we ignore the settings in
 484          * LD_LIBRARY_PATH.
 485          */
 486         if ((auxvt[AT_UID].a_un.a_val == (size_t)-1 && _dl_suid_ok()) ||
 487             (auxvt[AT_UID].a_un.a_val != (size_t)-1 &&
 488              auxvt[AT_UID].a_un.a_val == auxvt[AT_EUID].a_un.a_val &&
 489              auxvt[AT_GID].a_un.a_val == auxvt[AT_EGID].a_un.a_val)) {
 490                 _dl_secure = 0;
 491 #ifdef __LDSO_PRELOAD_ENV_SUPPORT__
 492                 _dl_preload = _dl_getenv("LD_PRELOAD", envp);
 493 #endif
 494 #ifdef __LDSO_LD_LIBRARY_PATH__
 495                 _dl_library_path = _dl_getenv("LD_LIBRARY_PATH", envp);
 496 #endif
 497         } else {
 498                 static const char unsecure_envvars[] =
 499 #ifdef EXTRA_UNSECURE_ENVVARS
 500                         EXTRA_UNSECURE_ENVVARS
 501 #endif
 502                         UNSECURE_ENVVARS;
 503                 const char *nextp;
 504                 _dl_secure = 1;
 505
 506 #ifdef __LDSO_PRELOAD_ENV_SUPPORT__
 507                 _dl_preload = _dl_getenv("LD_PRELOAD", envp);
 508 #endif
 509                 nextp = unsecure_envvars;
 510                 do {
 511                         _dl_unsetenv (nextp, envp);
 512                         /* We could use rawmemchr but this need not be fast.  */
 513                         nextp = _dl_strchr(nextp, '\0') + 1;
 514                 } while (*nextp != '\0');
 515 #ifdef __LDSO_LD_LIBRARY_PATH__
 516                 _dl_library_path = NULL;
 517 #endif
 518                 /* SUID binaries can be exploited if they do LAZY relocation. */
 519                 unlazy = RTLD_NOW;
 520         }
 521
 522 #if defined(USE_TLS) && USE_TLS
 523         _dl_error_catch_tsd = &_dl_initial_error_catch_tsd;
 524         _dl_init_static_tls = &_dl_nothread_init_static_tls;
 525 #endif
 526
 527 #ifdef __LDSO_STANDALONE_SUPPORT__
 528         if (_start == (void *) auxvt[AT_ENTRY].a_un.a_val) {
 529                 unsigned int *aux_dat = (unsigned int *) argv;
 530                 int argc = aux_dat[-1];
 531
 532                 tpnt->libname = argv[0];
 533                 while (argc > 1)
 534                         if (! _dl_strcmp (argv[1], "--library-path") && argc > 2) {
 535 #ifdef __LDSO_LD_LIBRARY_PATH__
 536                                 _dl_library_path = argv[2];
 537 #endif
 538                                 _dl_skip_args += 2;
 539                                 argc -= 2;
 540                                 argv += 2;
 541                         } else
 542                                 break;
 543
 544         /*
 545          * If we have no further argument the program was called incorrectly.
 546          * Grant the user some education.
 547          */
 548
 549                 if (argc < 2) {
 550                         _dl_dprintf(1, "\
 551 Usage: ld.so [OPTION]... EXECUTABLE-FILE [ARGS-FOR-PROGRAM...]\n\
 552 You have invoked `ld.so', the helper program for shared library executables.\n\
 553 This program usually lives in the file `/lib/ld.so', and special directives\n\
 554 in executable files using ELF shared libraries tell the system's program\n\
 555 loader to load the helper program from this file.  This helper program loads\n\
 556 the shared libraries needed by the program executable, prepares the program\n\
 557 to run, and runs it.  You may invoke this helper program directly from the\n\
 558 command line to load and run an ELF executable file; this is like executing\n\
 559 that file itself, but always uses this helper program from the file you\n\
 560 specified, instead of the helper program file specified in the executable\n\
 561 file you run.  This is mostly of use for maintainers to test new versions\n\
 562 of this helper program; chances are you did not intend to run this program.\n\
 563 \n\
 564   --library-path PATH   use given PATH instead of content of the environment\n\
 565                         variable LD_LIBRARY_PATH\n");
 566                         _dl_exit(1);
 567                 }
 568
 569                 ++_dl_skip_args;
 570                 ++argv;
 571                 _dl_progname = argv[0];
 572
 573                 _dl_symbol_tables = rpnt = _dl_zalloc(sizeof(struct dyn_elf));
 574                 /*
 575                  * It needs to load the _dl_progname and to map it
 576                  * Usually it is the main application launched by means of the ld.so
 577                  * but it could be also a shared object (when ld.so used for tracing)
 578                  * We keep the misleading app_tpnt name to avoid variable pollution
 579                  */
 580                 app_tpnt = _dl_load_elf_shared_library(_dl_secure, &rpnt, _dl_progname);
 581                 if (!app_tpnt) {
 582                         _dl_dprintf(2, "can't load '%s'\n", _dl_progname);
 583                         _dl_exit(16);
 584                 }
 585                 /*
 586                  * FIXME: it needs to properly handle a PIE executable
 587                  * Usually for a main application, loadaddr is computed as difference
 588                  * between auxvt entry points and phdr, so if it is not 0, that it is a
 589                  * PIE executable. In this case instead we need to set the loadaddr to 0
 590                  * because we are actually mapping the ELF for the main application by
 591                  * ourselves. So the PIE case must be checked.
 592                  */
 593
 594                 app_tpnt->rtld_flags = unlazy | RTLD_GLOBAL;
 595
 596                 /*
 597                  * This is used by gdb to locate the chain of shared libraries that are
 598                  * currently loaded.
 599                  */
 600                 debug_addr = _dl_zalloc(sizeof(struct r_debug));
 601                 ppnt = (ElfW(Phdr) *)app_tpnt->ppnt;
 602                 for (i = 0; i < app_tpnt->n_phent; i++, ppnt++) {
 603                         if (ppnt->p_type == PT_DYNAMIC) {
 604                                 dpnt = (ElfW(Dyn) *) DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr);
 605                                 _dl_parse_dynamic_info(dpnt, app_tpnt->dynamic_info, debug_addr, app_tpnt->loadaddr);
 606                         }
 607                 }
 608
 609                 _dl_ldsopath_init(tpnt);
 610         } else {
 611 #endif
 612
 613         /* At this point we are now free to examine the user application,
 614          * and figure out which libraries are supposed to be called.  Until
 615          * we have this list, we will not be completely ready for dynamic
 616          * linking.
 617          */
 618
 619         /* Find the runtime load address of the main executable.  This may be
 620          * different from what the ELF header says for ET_DYN/PIE executables.
 621          */
 622         {
 623                 unsigned int idx;
 624                 ElfW(Phdr) *phdr = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
 625
 626                 for (idx = 0; idx < auxvt[AT_PHNUM].a_un.a_val; idx++, phdr++)
 627                         if (phdr->p_type == PT_PHDR) {
 628                                 DL_INIT_LOADADDR_PROG(app_tpnt->loadaddr, auxvt[AT_PHDR].a_un.a_val - phdr->p_vaddr);
 629                                 break;
 630                         }
 631
 632                 if (DL_LOADADDR_BASE(app_tpnt->loadaddr))
 633                         _dl_debug_early("Position Independent Executable: "
 634                                         "app_tpnt->loadaddr=%x\n", DL_LOADADDR_BASE(app_tpnt->loadaddr));
 635         }
 636
 637         /*
 638          * This is used by gdb to locate the chain of shared libraries that are
 639          * currently loaded.
 640          */
 641         debug_addr = _dl_zalloc(sizeof(struct r_debug));
 642
 643         ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
 644         for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++) {
 645                 if (ppnt->p_type == PT_GNU_RELRO) {
 646                         relro_addr = ppnt->p_vaddr;
 647                         relro_size = ppnt->p_memsz;
 648                 }
 649                 if (!app_mapaddr && (ppnt->p_type == PT_LOAD)) {
 650                         app_mapaddr = DL_RELOC_ADDR (app_tpnt->loadaddr, ppnt->p_vaddr);
 651                 }
 652                 if (ppnt->p_type == PT_DYNAMIC) {
 653                         dpnt = (ElfW(Dyn) *) DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr);
 654                         _dl_parse_dynamic_info(dpnt, app_tpnt->dynamic_info, debug_addr, app_tpnt->loadaddr);
 655 #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
 656                         /* Ugly, ugly.  We need to call mprotect to change the
 657                          * protection of the text pages so that we can do the
 658                          * dynamic linking.  We can set the protection back
 659                          * again once we are done.
 660                          */
 661                         _dl_debug_early("calling mprotect on the application program\n");
 662                         /* Now cover the application program. */
 663                         if (app_tpnt->dynamic_info[DT_TEXTREL]) {
 664                                 ElfW(Phdr) *ppnt_outer = ppnt;
 665                                 ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
 666                                 for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++) {
 667                                         if (ppnt->p_type == PT_LOAD && !(ppnt->p_flags & PF_W))
 668                                                 _dl_mprotect((void *) (DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr) & PAGE_ALIGN),
 669                                                              (DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr) & ADDR_ALIGN) +
 670                                                              (unsigned long) ppnt->p_filesz,
 671                                                              PROT_READ | PROT_WRITE | PROT_EXEC);
 672                                 }
 673                                 ppnt = ppnt_outer;
 674                         }
 675 #else
 676                         if (app_tpnt->dynamic_info[DT_TEXTREL]) {
 677                                 _dl_dprintf(2, "Can't modify application's text section; use the GCC option -fPIE for position-independent executables.\n");
 678                                 _dl_exit(1);
 679                         }
 680 #endif
 681
 682 #ifndef ALLOW_ZERO_PLTGOT
 683                         /* make sure it's really there. */
 684                         if (app_tpnt->dynamic_info[DT_PLTGOT] == 0)
 685                                 continue;
 686 #endif
 687                         /* OK, we have what we need - slip this one into the list. */
 688                         app_tpnt = _dl_add_elf_hash_table(_dl_progname, app_tpnt->loadaddr,
 689                                         app_tpnt->dynamic_info,
 690                                         (unsigned long) DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr),
 691                                         ppnt->p_filesz);
 692                         _dl_loaded_modules->libtype = elf_executable;
 693                         _dl_loaded_modules->ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
 694                         _dl_loaded_modules->n_phent = auxvt[AT_PHNUM].a_un.a_val;
 695                         _dl_symbol_tables = rpnt = _dl_zalloc(sizeof(struct dyn_elf));
 696                         rpnt->dyn = _dl_loaded_modules;
 697                         app_tpnt->mapaddr = app_mapaddr;
 698                         app_tpnt->rtld_flags = unlazy | RTLD_GLOBAL;
 699                         app_tpnt->usage_count++;
 700 #ifdef __DSBT__
 701                         _dl_ldso_dsbt[0] = app_tpnt->dsbt_table;
 702                         _dl_memcpy(app_tpnt->dsbt_table, _dl_ldso_dsbt,
 703                                    app_tpnt->dsbt_size * sizeof(tpnt->dsbt_table[0]));
 704 #endif
 705                         lpnt = (unsigned long *) (app_tpnt->dynamic_info[DT_PLTGOT]);
 706 #ifdef ALLOW_ZERO_PLTGOT
 707                         if (lpnt)
 708 #endif
 709                                 INIT_GOT(lpnt, _dl_loaded_modules);
 710                 }
 711
 712                 /* OK, fill this in - we did not have this before */
 713                 if (ppnt->p_type == PT_INTERP) {
 714                         tpnt->libname = (char *) DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr);
 715
 716                         _dl_ldsopath_init(tpnt);
 717                 }
 718
 719                 /* Discover any TLS sections if the target supports them. */
 720                 if (ppnt->p_type == PT_TLS) {
 721 #if defined(USE_TLS) && USE_TLS
 722                         if (ppnt->p_memsz > 0) {
 723                                 app_tpnt->l_tls_blocksize = ppnt->p_memsz;
 724                                 app_tpnt->l_tls_align = ppnt->p_align;
 725                                 if (ppnt->p_align == 0)
 726                                         app_tpnt->l_tls_firstbyte_offset = 0;
 727                                 else
 728                                         app_tpnt->l_tls_firstbyte_offset =
 729                                                 (ppnt->p_vaddr & (ppnt->p_align - 1));
 730                                 app_tpnt->l_tls_initimage_size = ppnt->p_filesz;
 731                                 app_tpnt->l_tls_initimage = (void *) ppnt->p_vaddr;
 732
 733                                 /* This image gets the ID one.  */
 734                                 _dl_tls_max_dtv_idx = app_tpnt->l_tls_modid = 1;
 735
 736                         }
 737                         _dl_debug_early("Found TLS header for application program\n");
 738                         break;
 739 #else
 740                         _dl_dprintf(2, "Program uses unsupported TLS data!\n");
 741                         _dl_exit(1);
 742 #endif
 743                 }
 744         }
 745         app_tpnt->relro_addr = relro_addr;
 746         app_tpnt->relro_size = relro_size;
 747
 748 #if defined(USE_TLS) && USE_TLS
 749         /*
 750          * Adjust the address of the TLS initialization image in
 751          * case the executable is actually an ET_DYN object.
 752          */
 753         if (app_tpnt->l_tls_initimage != NULL) {
 754                 unsigned int tmp = (unsigned int) app_tpnt->l_tls_initimage;
 755                 app_tpnt->l_tls_initimage =
 756                         (char *) app_tpnt->l_tls_initimage + app_tpnt->loadaddr;
 757                 _dl_debug_early("Relocated TLS initial image from %x to %x (size = %x)\n",
 758                         tmp, app_tpnt->l_tls_initimage, app_tpnt->l_tls_initimage_size);
 759         }
 760 #endif
 761
 762 #ifdef __LDSO_STANDALONE_SUPPORT__
 763         } /* ! ldso standalone mode */
 764 #endif
 765
 766 #ifdef __SUPPORT_LD_DEBUG__
 767         _dl_debug = _dl_getenv("LD_DEBUG", envp);
 768         if (_dl_debug) {
 769                 if (_dl_strstr(_dl_debug, "all")) {
 770                         _dl_debug_detail = _dl_debug_move = _dl_debug_symbols
 771                                 = _dl_debug_reloc = _dl_debug_bindings = _dl_debug_nofixups = (void*)1;
 772                 } else {
 773                         _dl_debug_detail   = _dl_strstr(_dl_debug, "detail");
 774                         _dl_debug_move     = _dl_strstr(_dl_debug, "move");
 775                         _dl_debug_symbols  = _dl_strstr(_dl_debug, "sym");
 776                         _dl_debug_reloc    = _dl_strstr(_dl_debug, "reloc");
 777                         _dl_debug_nofixups = _dl_strstr(_dl_debug, "nofix");
 778                         _dl_debug_bindings = _dl_strstr(_dl_debug, "bind");
 779                 }
 780         }
 781
 782         {
 783                 const char *dl_debug_output;
 784
 785                 dl_debug_output = _dl_getenv("LD_DEBUG_OUTPUT", envp);
 786
 787                 if (dl_debug_output) {
 788                         char tmp[22], *tmp1, *filename;
 789                         int len1, len2;
 790
 791                         _dl_memset(tmp, 0, sizeof(tmp));
 792                         tmp1 = _dl_simple_ltoa( tmp, (unsigned long)_dl_getpid());
 793
 794                         len1 = _dl_strlen(dl_debug_output);
 795                         len2 = _dl_strlen(tmp1);
 796
 797                         filename = _dl_malloc(len1 + len2 + 2);
 798
 799                         if (filename) {
 800                                 _dl_strcpy (filename, dl_debug_output);
 801                                 filename[len1] = '.';
 802                                 _dl_strcpy (&filename[len1+1], tmp1);
 803
 804                                 _dl_debug_file = _dl_open(filename, O_WRONLY|O_CREAT, 0644);
 805                                 if (_dl_debug_file < 0) {
 806                                         _dl_debug_file = 2;
 807                                         _dl_dprintf(_dl_debug_file, "can't open file: '%s'\n",filename);
 808                                 }
 809                         }
 810                 }
 811         }
 812 #endif
 813
 814 #ifdef __LDSO_PRELINK_SUPPORT__
 815 {
 816         char *ld_warn = _dl_getenv ("LD_WARN", envp);
 817
 818         if (ld_warn && *ld_warn == '\0')
 819                 _dl_verbose = false;
 820 }
 821         _dl_trace_prelink = _dl_getenv("LD_TRACE_PRELINKING", envp);
 822 #endif
 823
 824         if (_dl_getenv("LD_TRACE_LOADED_OBJECTS", envp) != NULL) {
 825                 trace_loaded_objects++;
 826         }
 827
 828 #ifndef __LDSO_LDD_SUPPORT__
 829         if (trace_loaded_objects) {
 830                 _dl_dprintf(2, "Use the ldd provided by uClibc\n");
 831                 _dl_exit(1);
 832         }
 833 #endif
 834
 835         ldso_mapaddr = (ElfW(Addr)) auxvt[AT_BASE].a_un.a_val;
 836         /*
 837          * OK, fix one more thing - set up debug_addr so it will point
 838          * to our chain.  Later we may need to fill in more fields, but this
 839          * should be enough for now.
 840          */
 841         debug_addr->r_map = (struct link_map *) _dl_loaded_modules;
 842         debug_addr->r_version = 1;
 843         debug_addr->r_ldbase = (ElfW(Addr))
 844                 DL_LOADADDR_BASE(DL_GET_RUN_ADDR(load_addr, ldso_mapaddr));
 845         debug_addr->r_brk = (unsigned long) &_dl_debug_state;
 846         _dl_debug_addr = debug_addr;
 847
 848         /* Do not notify the debugger until the interpreter is in the list */
 849
 850         /* OK, we now have the application in the list, and we have some
 851          * basic stuff in place.  Now search through the list for other shared
 852          * libraries that should be loaded, and insert them on the list in the
 853          * correct order.
 854          */
 855
 856         _dl_map_cache();
 857
 858 #ifdef __LDSO_PRELOAD_ENV_SUPPORT__
 859         if (_dl_preload) {
 860                 char c, *str, *str2;
 861
 862                 str = _dl_preload;
 863                 while (*str == ':' || *str == ' ' || *str == '\t')
 864                         str++;
 865
 866                 while (*str) {
 867                         str2 = str;
 868                         while (*str2 && *str2 != ':' && *str2 != ' ' && *str2 != '\t')
 869                                 str2++;
 870                         c = *str2;
 871                         *str2 = '\0';
 872
 873                         if (!_dl_secure || _dl_strchr(str, '/') == NULL) {
 874                                 _dl_if_debug_dprint("\tfile='%s';  needed by '%s'\n", str, _dl_progname);
 875
 876                                 tpnt1 = _dl_load_shared_library(
 877                                         _dl_secure ? DL_RESOLVE_SECURE : 0,
 878                                         &rpnt, NULL, str, trace_loaded_objects);
 879                                 if (!tpnt1) {
 880 #ifdef __LDSO_LDD_SUPPORT__
 881                                         if (trace_loaded_objects || _dl_trace_prelink)
 882                                                 _dl_dprintf(1, "\t%s => not found\n", str);
 883                                         else
 884 #endif
 885                                         {
 886                                                 _dl_dprintf(2, "%s: library '%s' "
 887                                                         "from LD_PRELOAD can't be preloaded: ignored.\n",
 888                                                         _dl_progname, str);
 889                                         }
 890                                 } else {
 891                                         tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
 892
 893                                         _dl_debug_early("Loading: (%x) %s\n", DL_LOADADDR_BASE(tpnt1->loadaddr), tpnt1->libname);
 894
 895 #ifdef __LDSO_LDD_SUPPORT__
 896                                         if (trace_loaded_objects && !_dl_trace_prelink &&
 897                                             tpnt1->usage_count == 1) {
 898                                                 /* This is a real hack to make
 899                                                  * ldd not print the library
 900                                                  * itself when run on a
 901                                                  * library.
 902                                                  */
 903                                                 if (_dl_strcmp(_dl_progname, str) != 0)
 904                                                         _dl_dprintf(1, "\t%s => %s (%x)\n", str, tpnt1->libname,
 905                                                                     DL_LOADADDR_BASE(tpnt1->loadaddr));
 906                                         }
 907 #endif
 908                                 }
 909                         }
 910
 911                         *str2 = c;
 912                         str = str2;
 913                         while (*str == ':' || *str == ' ' || *str == '\t')
 914                                 str++;
 915                 }
 916         }
 917 #endif /* __LDSO_PRELOAD_ENV_SUPPORT__ */
 918
 919 #ifdef __LDSO_PRELOAD_FILE_SUPPORT__
 920         do {
 921                 char *preload;
 922                 int fd;
 923                 char c, *cp, *cp2;
 924                 struct stat st;
 925
 926                 if (_dl_stat(LDSO_PRELOAD, &st) || st.st_size == 0) {
 927                         break;
 928                 }
 929
 930                 if ((fd = _dl_open(LDSO_PRELOAD, O_RDONLY, 0)) < 0) {
 931                         _dl_dprintf(2, "%s: can't open file '%s'\n",
 932                                     _dl_progname, LDSO_PRELOAD);
 933                         break;
 934                 }
 935
 936                 preload = (caddr_t) _dl_mmap(0, st.st_size + 1,
 937                                              PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
 938                 _dl_close(fd);
 939                 if (preload == (caddr_t) -1) {
 940                         _dl_dprintf(2, "%s:%i: can't map '%s'\n",
 941                                     _dl_progname, __LINE__, LDSO_PRELOAD);
 942                         break;
 943                 }
 944
 945                 /* convert all separators and comments to spaces */
 946                 for (cp = preload; *cp; /*nada */ ) {
 947                         if (*cp == ':' || *cp == '\t' || *cp == '\n') {
 948                                 *cp++ = ' ';
 949                         } else if (*cp == '#') {
 950                                 do {
 951                                         *cp++ = ' ';
 952                                 } while (*cp != '\n' && *cp != '\0');
 953                         } else {
 954                                 cp++;
 955                         }
 956                 }
 957
 958                 /* find start of first library */
 959                 for (cp = preload; *cp && *cp == ' '; cp++)
 960                         /*nada */ ;
 961
 962                 while (*cp) {
 963                         /* find end of library */
 964                         for (cp2 = cp; *cp && *cp != ' '; cp++)
 965                                 /*nada */ ;
 966                         c = *cp;
 967                         *cp = '\0';
 968
 969                         _dl_if_debug_dprint("\tfile='%s';  needed by '%s'\n", cp2, _dl_progname);
 970
 971                         tpnt1 = _dl_load_shared_library(0, &rpnt, NULL, cp2, trace_loaded_objects);
 972                         if (!tpnt1) {
 973 # ifdef __LDSO_LDD_SUPPORT__
 974                                 if (trace_loaded_objects || _dl_trace_prelink)
 975                                         _dl_dprintf(1, "\t%s => not found\n", cp2);
 976                                 else
 977 # endif
 978                                 {
 979                                         _dl_dprintf(2, "%s: can't load library '%s'\n", _dl_progname, cp2);
 980                                         _dl_exit(15);
 981                                 }
 982                         } else {
 983                                 tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
 984
 985                                 _dl_debug_early("Loading: (%x) %s\n", DL_LOADADDR_BASE(tpnt1->loadaddr), tpnt1->libname);
 986
 987 # ifdef __LDSO_LDD_SUPPORT__
 988                                 if (trace_loaded_objects && !_dl_trace_prelink &&
 989                                     tpnt1->usage_count == 1) {
 990                                         _dl_dprintf(1, "\t%s => %s (%x)\n",
 991                                                     cp2, tpnt1->libname,
 992                                                     DL_LOADADDR_BASE(tpnt1->loadaddr));
 993                                 }
 994 # endif
 995                         }
 996
 997                         /* find start of next library */
 998                         *cp = c;
 999                         for ( /*nada */ ; *cp && *cp == ' '; cp++)
1000                                 /*nada */ ;
1001                 }
1002
1003                 _dl_munmap(preload, st.st_size + 1);
1004         } while (0);
1005 #endif /* __LDSO_PRELOAD_FILE_SUPPORT__ */
1006
1007         nlist = 0;
1008         for (tcurr = _dl_loaded_modules; tcurr; tcurr = tcurr->next) {
1009                 ElfW(Dyn) *this_dpnt;
1010
1011                 nlist++;
1012                 for (this_dpnt = (ElfW(Dyn) *) tcurr->dynamic_addr; this_dpnt->d_tag; this_dpnt++) {
1013                         if (this_dpnt->d_tag == DT_NEEDED) {
1014                                 char *name;
1015                                 struct init_fini_list *tmp;
1016
1017                                 lpntstr = (char*) (tcurr->dynamic_info[DT_STRTAB] + this_dpnt->d_un.d_val);
1018                                 name = _dl_get_last_path_component(lpntstr);
1019                                 _dl_if_debug_dprint("\tfile='%s';  needed by '%s'\n", lpntstr, _dl_progname);
1020
1021                                 if (_dl_strcmp(name, UCLIBC_LDSO) == 0) {
1022                                                 if (!ldso_tpnt) {
1023                                                         /* Insert the ld.so only once */
1024                                                         ldso_tpnt = add_ldso(tpnt, load_addr,
1025                                                                                                  ldso_mapaddr, auxvt, rpnt);
1026                                                 }
1027                                                 ldso_tpnt->usage_count++;
1028                                                 tpnt1 = ldso_tpnt;
1029                                 } else
1030                                         tpnt1 = _dl_load_shared_library(0, &rpnt, tcurr, lpntstr, trace_loaded_objects);
1031
1032                                 if (!tpnt1) {
1033 #ifdef __LDSO_LDD_SUPPORT__
1034                                         if (trace_loaded_objects || _dl_trace_prelink) {
1035                                                 _dl_dprintf(1, "\t%s => not found\n", lpntstr);
1036                                                 continue;
1037                                         } else
1038 #endif
1039                                         {
1040                                                 _dl_dprintf(2, "%s: can't load library '%s'\n", _dl_progname, lpntstr);
1041                                                 _dl_exit(16);
1042                                         }
1043                                 }
1044
1045                                 tmp = alloca(sizeof(struct init_fini_list)); /* Allocates on stack, no need to free this memory */
1046                                 tmp->tpnt = tpnt1;
1047                                 tmp->next = tcurr->init_fini;
1048                                 tcurr->init_fini = tmp;
1049
1050                                 tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
1051
1052                                 _dl_debug_early("Loading: (%x) %s\n", DL_LOADADDR_BASE(tpnt1->loadaddr), tpnt1->libname);
1053
1054 #ifdef __LDSO_LDD_SUPPORT__
1055                                 if (trace_loaded_objects && !_dl_trace_prelink &&
1056                                     tpnt1->usage_count == 1) {
1057                                         _dl_dprintf(1, "\t%s => %s (%x)\n",
1058                                                     lpntstr, tpnt1->libname,
1059                                                     DL_LOADADDR_BASE(tpnt1->loadaddr));
1060                                 }
1061 #endif
1062                         }
1063                 }
1064         }
1065         _dl_unmap_cache();
1066
1067         /* Keep track of the number of elements in the global scope */
1068         nscope_elem = nlist;
1069
1070         if (_dl_loaded_modules->libtype == elf_executable) {
1071                 --nlist; /* Exclude the application. */
1072                 tcurr = _dl_loaded_modules->next;
1073         } else
1074                 tcurr = _dl_loaded_modules;
1075         init_fini_list = _dl_malloc(nlist * sizeof(struct elf_resolve *));
1076         i = 0;
1077         for (; tcurr; tcurr = tcurr->next)
1078                 init_fini_list[i++] = tcurr;
1079
1080         /* Sort the INIT/FINI list in dependency order. */
1081         for (tcurr = _dl_loaded_modules->next; tcurr; tcurr = tcurr->next) {
1082                 unsigned int j, k;
1083
1084                 for (j = 0; init_fini_list[j] != tcurr; ++j)
1085                         /* Empty */;
1086                 for (k = j + 1; k < nlist; ++k) {
1087                         struct init_fini_list *runp = init_fini_list[k]->init_fini;
1088
1089                         for (; runp; runp = runp->next) {
1090                                 if (runp->tpnt == tcurr) {
1091                                         struct elf_resolve *here = init_fini_list[k];
1092                                         _dl_if_debug_dprint("Move %s from pos %d to %d in INIT/FINI list\n", here->libname, k, j);
1093                                         for (i = (k - j); i; --i)
1094                                                 init_fini_list[i+j] = init_fini_list[i+j-1];
1095                                         init_fini_list[j] = here;
1096                                         ++j;
1097                                         break;
1098                                 }
1099                         }
1100                 }
1101         }
1102 #ifdef __SUPPORT_LD_DEBUG__
1103         if (_dl_debug) {
1104                 _dl_dprintf(_dl_debug_file, "\nINIT/FINI order and dependencies:\n");
1105                 for (i = 0; i < nlist; i++) {
1106                         struct init_fini_list *tmp;
1107
1108                         _dl_dprintf(_dl_debug_file, "lib: %s has deps:\n",
1109                                     init_fini_list[i]->libname);
1110                         tmp = init_fini_list[i]->init_fini;
1111                         for (; tmp; tmp = tmp->next)
1112                                 _dl_dprintf(_dl_debug_file, " %s ", tmp->tpnt->libname);
1113                         _dl_dprintf(_dl_debug_file, "\n");
1114                 }
1115         }
1116 #endif
1117
1118         /*
1119          * If the program interpreter is not in the module chain, add it.
1120          * This will be required for dlopen to be able to access the internal
1121          * functions in the dynamic linker and to relocate the interpreter
1122          * again once all libs are loaded.
1123          */
1124         if (!ldso_tpnt) {
1125                 tpnt = add_ldso(tpnt, load_addr, ldso_mapaddr, auxvt, rpnt);
1126                 tpnt->usage_count++;
1127                 nscope_elem++;
1128         } else
1129                 tpnt = ldso_tpnt;
1130
1131 #ifdef RERELOCATE_LDSO
1132                 /* Only rerelocate functions for now. */
1133                 tpnt->init_flag = RELOCS_DONE;
1134                 lpnt = (unsigned long *) (tpnt->dynamic_info[DT_PLTGOT]);
1135 # ifdef ALLOW_ZERO_PLTGOT
1136                 if (tpnt->dynamic_info[DT_PLTGOT])
1137 # endif
1138                         INIT_GOT(lpnt, tpnt);
1139 #else
1140                 tpnt->init_flag = RELOCS_DONE | JMP_RELOCS_DONE;
1141 #endif
1142                 tpnt = NULL;
1143
1144         /*
1145          * Allocate the global scope array.
1146          */
1147         scope_elem_list = (struct elf_resolve **) _dl_malloc(nscope_elem * sizeof(struct elf_resolve *));
1148
1149         for (i = 0, tcurr = _dl_loaded_modules; tcurr; tcurr = tcurr->next)
1150                 scope_elem_list[i++] = tcurr;
1151
1152         _dl_loaded_modules->symbol_scope.r_list = scope_elem_list;
1153         _dl_loaded_modules->symbol_scope.r_nlist = nscope_elem;
1154         /*
1155          * The symbol scope of the application, that is the first entry of the
1156          * _dl_loaded_modules list, is just the global scope to be used for the
1157          * symbol lookup.
1158          */
1159         global_scope = &_dl_loaded_modules->symbol_scope;
1160
1161         /* Build the local scope for each loaded modules. */
1162         local_scope = _dl_malloc(nscope_elem * sizeof(struct elf_resolve *));
1163         i = 1;
1164         for (tcurr = _dl_loaded_modules->next; tcurr; tcurr = tcurr->next) {
1165                 unsigned int k;
1166                 cnt = _dl_build_local_scope(local_scope, scope_elem_list[i++]);
1167                 tcurr->symbol_scope.r_list = _dl_malloc(cnt * sizeof(struct elf_resolve *));
1168                 tcurr->symbol_scope.r_nlist = cnt;
1169                 _dl_memcpy (tcurr->symbol_scope.r_list, local_scope, cnt * sizeof (struct elf_resolve *));
1170                 /* Restoring the init_flag.*/
1171                 for (k = 1; k < nscope_elem; k++)
1172                         scope_elem_list[k]->init_flag &= ~DL_RESERVED;
1173         }
1174
1175         _dl_free(local_scope);
1176
1177 #ifdef __LDSO_LDD_SUPPORT__
1178         /* Exit if LD_TRACE_LOADED_OBJECTS is on. */
1179         if (trace_loaded_objects && !_dl_trace_prelink)
1180                 _dl_exit(0);
1181 #endif
1182
1183 #if defined(USE_TLS) && USE_TLS
1184         /* We do not initialize any of the TLS functionality unless any of the
1185          * initial modules uses TLS.  This makes dynamic loading of modules with
1186          * TLS impossible, but to support it requires either eagerly doing setup
1187          * now or lazily doing it later.  Doing it now makes us incompatible with
1188          * an old kernel that can't perform TLS_INIT_TP, even if no TLS is ever
1189          * used.  Trying to do it lazily is too hairy to try when there could be
1190          * multiple threads (from a non-TLS-using libpthread).  */
1191         bool was_tls_init_tp_called = tls_init_tp_called;
1192         if (tcbp == NULL) {
1193                 _dl_debug_early("Calling init_tls()!\n");
1194                 tcbp = init_tls ();
1195         }
1196 #endif
1197 #ifdef __UCLIBC_HAS_SSP__
1198         /* Set up the stack checker's canary.  */
1199         stack_chk_guard = _dl_setup_stack_chk_guard ();
1200 # ifdef THREAD_SET_STACK_GUARD
1201         THREAD_SET_STACK_GUARD (stack_chk_guard);
1202 # else
1203         __stack_chk_guard = stack_chk_guard;
1204 # endif
1205 # ifdef __UCLIBC_HAS_SSP_COMPAT__
1206         __guard = stack_chk_guard;
1207 # endif
1208 #endif
1209
1210 #ifdef __LDSO_PRELINK_SUPPORT__
1211         if (_dl_trace_prelink) {
1212
1213                 unsigned int nscope_trace = ldso_tpnt ? nscope_elem : (nscope_elem - 1);
1214
1215                 for (i = 0; i < nscope_trace; i++)
1216                         trace_objects(scope_elem_list[i],
1217                                 _dl_get_last_path_component(scope_elem_list[i]->libname));
1218
1219                 if (_dl_verbose)
1220                         /* Warn about undefined symbols. */
1221                         if (_dl_symbol_tables)
1222                                 if (_dl_fixup(_dl_symbol_tables, global_scope, unlazy))
1223                                         _dl_exit(-1);
1224                 _dl_exit(0);
1225         }
1226
1227         if (_dl_loaded_modules->dynamic_info[DT_GNU_LIBLIST_IDX]) {
1228                 ElfW(Lib) *liblist, *liblistend;
1229                 struct elf_resolve **r_list, **r_listend, *l;
1230                 const char *strtab = (const char *)_dl_loaded_modules->dynamic_info[DT_STRTAB];
1231
1232                 _dl_assert (_dl_loaded_modules->dynamic_info[DT_GNU_LIBLISTSZ_IDX] != 0);
1233                 liblist = (ElfW(Lib) *) _dl_loaded_modules->dynamic_info[DT_GNU_LIBLIST_IDX];
1234                 liblistend = (ElfW(Lib) *)
1235                 ((char *) liblist + _dl_loaded_modules->dynamic_info[DT_GNU_LIBLISTSZ_IDX]);
1236                 r_list = _dl_loaded_modules->symbol_scope.r_list;
1237                 r_listend = r_list + nscope_elem;
1238
1239                 for (; r_list < r_listend && liblist < liblistend; r_list++) {
1240                         l = *r_list;
1241
1242                         if (l == _dl_loaded_modules)
1243                                 continue;
1244
1245                         /* If the library is not mapped where it should, fail.  */
1246                         if (l->loadaddr)
1247                                 break;
1248
1249                         /* Next, check if checksum matches.  */
1250                         if (l->dynamic_info[DT_CHECKSUM_IDX] == 0 ||
1251                                 l->dynamic_info[DT_CHECKSUM_IDX] != liblist->l_checksum)
1252                                 break;
1253
1254                         if (l->dynamic_info[DT_GNU_PRELINKED_IDX] == 0 ||
1255                                 (l->dynamic_info[DT_GNU_PRELINKED_IDX] != liblist->l_time_stamp))
1256                                 break;
1257
1258                         if (_dl_strcmp(strtab + liblist->l_name, _dl_get_last_path_component(l->libname)) != 0)
1259                                 break;
1260
1261                         ++liblist;
1262                 }
1263
1264
1265                 if (r_list == r_listend && liblist == liblistend)
1266                         prelinked = true;
1267
1268         }
1269
1270         _dl_debug_early ("\nprelink checking: %s\n", prelinked ? "ok" : "failed");
1271
1272         if (prelinked) {
1273                 if (_dl_loaded_modules->dynamic_info[DT_GNU_CONFLICT_IDX]) {
1274                         ELF_RELOC *conflict;
1275                         unsigned long conflict_size;
1276
1277                         _dl_assert (_dl_loaded_modules->dynamic_info[DT_GNU_CONFLICTSZ_IDX] != 0);
1278                         conflict = (ELF_RELOC *) _dl_loaded_modules->dynamic_info[DT_GNU_CONFLICT_IDX];
1279                         conflict_size = _dl_loaded_modules->dynamic_info[DT_GNU_CONFLICTSZ_IDX];
1280                         _dl_parse_relocation_information(_dl_symbol_tables, global_scope,
1281                                 (unsigned long) conflict, conflict_size);
1282                 }
1283
1284                 /* Mark all the objects so we know they have been already relocated.  */
1285                 for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
1286                         tpnt->init_flag |= RELOCS_DONE;
1287                         if (tpnt->relro_size)
1288                                 _dl_protect_relro (tpnt);
1289                 }
1290         } else
1291 #endif
1292
1293         {
1294
1295         _dl_debug_early("Beginning relocation fixups\n");
1296
1297 #ifdef __mips__
1298         /*
1299          * Relocation of the GOT entries for MIPS have to be done
1300          * after all the libraries have been loaded.
1301          */
1302         _dl_perform_mips_global_got_relocations(_dl_loaded_modules, !unlazy);
1303 #endif
1304
1305         /*
1306          * OK, now all of the kids are tucked into bed in their proper
1307          * addresses.  Now we go through and look for REL and RELA records that
1308          * indicate fixups to the GOT tables.  We need to do this in reverse
1309          * order so that COPY directives work correctly.
1310          */
1311         if (_dl_symbol_tables)
1312                 if (_dl_fixup(_dl_symbol_tables, global_scope, unlazy))
1313                         _dl_exit(-1);
1314
1315         for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
1316                 if (tpnt->relro_size)
1317                         _dl_protect_relro (tpnt);
1318         }
1319         } /* not prelinked */
1320
1321 #if defined(USE_TLS) && USE_TLS
1322         if (!was_tls_init_tp_called && _dl_tls_max_dtv_idx > 0)
1323                 ++_dl_tls_generation;
1324
1325         _dl_debug_early("Calling _dl_allocate_tls_init()!\n");
1326
1327         /* Now that we have completed relocation, the initializer data
1328            for the TLS blocks has its final values and we can copy them
1329            into the main thread's TLS area, which we allocated above.  */
1330         _dl_allocate_tls_init (tcbp);
1331
1332         /* And finally install it for the main thread.  If ld.so itself uses
1333            TLS we know the thread pointer was initialized earlier.  */
1334         if (! tls_init_tp_called) {
1335                 const char *lossage = (char *) TLS_INIT_TP (tcbp, USE___THREAD);
1336                 if (__builtin_expect (lossage != NULL, 0)) {
1337                         _dl_debug_early("cannot set up thread-local storage: %s\n", lossage);
1338                         _dl_exit(30);
1339                 }
1340         }
1341 #endif /* USE_TLS */
1342
1343         /* OK, at this point things are pretty much ready to run.  Now we need
1344          * to touch up a few items that are required, and then we can let the
1345          * user application have at it.  Note that the dynamic linker itself
1346          * is not guaranteed to be fully dynamicly linked if we are using
1347          * ld.so.1, so we have to look up each symbol individually.
1348          */
1349
1350         _dl_envp = (unsigned long *) (intptr_t) _dl_find_hash(__C_SYMBOL_PREFIX__ "__environ", global_scope, NULL, 0, NULL);
1351         if (_dl_envp)
1352                 *_dl_envp = (unsigned long) envp;
1353
1354 #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
1355         {
1356                 unsigned int j;
1357                 ElfW(Phdr) *myppnt;
1358
1359                 /* We had to set the protections of all pages to R/W for
1360                  * dynamic linking.  Set text pages back to R/O.
1361                  */
1362                 for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
1363                         for (myppnt = tpnt->ppnt, j = 0; j < tpnt->n_phent; j++, myppnt++) {
1364                                 if (myppnt->p_type == PT_LOAD && !(myppnt->p_flags & PF_W) && tpnt->dynamic_info[DT_TEXTREL]) {
1365                                         _dl_mprotect((void *) (DL_RELOC_ADDR(tpnt->loadaddr, myppnt->p_vaddr) & PAGE_ALIGN),
1366                                                         (myppnt->p_vaddr & ADDR_ALIGN) + (unsigned long) myppnt->p_filesz, LXFLAGS(myppnt->p_flags));
1367                                 }
1368                         }
1369                 }
1370
1371         }
1372 #endif
1373         /* Notify the debugger we have added some objects. */
1374         _dl_debug_addr->r_state = RT_ADD;
1375         _dl_debug_state();
1376
1377         /* Run pre-initialization functions for the executable.  */
1378         _dl_run_array_forward(_dl_loaded_modules->dynamic_info[DT_PREINIT_ARRAY],
1379                               _dl_loaded_modules->dynamic_info[DT_PREINIT_ARRAYSZ],
1380                               _dl_loaded_modules->loadaddr);
1381
1382         /* Run initialization functions for loaded objects.  For the
1383            main executable, they will be run from __uClibc_main.  */
1384         for (i = nlist; i; --i) {
1385                 tpnt = init_fini_list[i-1];
1386                 tpnt->init_fini = NULL; /* Clear, since alloca was used */
1387                 if (tpnt->init_flag & INIT_FUNCS_CALLED)
1388                         continue;
1389                 tpnt->init_flag |= INIT_FUNCS_CALLED;
1390
1391                 if (tpnt->dynamic_info[DT_INIT]) {
1392                         void (*dl_elf_func) (void);
1393
1394                         dl_elf_func = (void (*)(void)) DL_RELOC_ADDR(tpnt->loadaddr, tpnt->dynamic_info[DT_INIT]);
1395
1396                         _dl_if_debug_dprint("calling INIT: %s\n\n", tpnt->libname);
1397
1398                         DL_CALL_FUNC_AT_ADDR (dl_elf_func, tpnt->loadaddr, (void(*)(void)));
1399                 }
1400
1401                 _dl_run_init_array(tpnt);
1402         }
1403
1404         /* Find the real malloc function and make ldso functions use that from now on */
1405         _dl_malloc_function = (void* (*)(size_t)) (intptr_t) _dl_find_hash(__C_SYMBOL_PREFIX__ "malloc",
1406                         global_scope, NULL, ELF_RTYPE_CLASS_PLT, NULL);
1407
1408 #if defined(USE_TLS) && USE_TLS
1409         /* Find the real functions and make ldso functions use them from now on */
1410         _dl_calloc_function = (void* (*)(size_t, size_t)) (intptr_t)
1411                 _dl_find_hash(__C_SYMBOL_PREFIX__ "calloc", global_scope, NULL, ELF_RTYPE_CLASS_PLT, NULL);
1412
1413         _dl_realloc_function = (void* (*)(void *, size_t)) (intptr_t)
1414                 _dl_find_hash(__C_SYMBOL_PREFIX__ "realloc", global_scope, NULL, ELF_RTYPE_CLASS_PLT, NULL);
1415
1416         _dl_free_function = (void (*)(void *)) (intptr_t)
1417                 _dl_find_hash(__C_SYMBOL_PREFIX__ "free", global_scope, NULL, ELF_RTYPE_CLASS_PLT, NULL);
1418
1419         _dl_memalign_function = (void* (*)(size_t, size_t)) (intptr_t)
1420                 _dl_find_hash(__C_SYMBOL_PREFIX__ "memalign", global_scope, NULL, ELF_RTYPE_CLASS_PLT, NULL);
1421
1422 #endif
1423
1424         /* Notify the debugger that all objects are now mapped in.  */
1425         _dl_debug_addr->r_state = RT_CONSISTENT;
1426         _dl_debug_state();
1427
1428 #ifdef __LDSO_STANDALONE_SUPPORT__
1429         if (_start == (void *) auxvt[AT_ENTRY].a_un.a_val)
1430                 return (void *) app_tpnt->l_entry;
1431         else
1432 #endif
1433                 return (void *) auxvt[AT_ENTRY].a_un.a_val;
1434 }
1435
1436 #include "dl-hash.c"
1437 #include "dl-elf.c"