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 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_UNINITIALIZED, -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                 char *tmp attribute_unused =
 755                         (char *) app_tpnt->l_tls_initimage;
 756                 app_tpnt->l_tls_initimage =
 757                         (char *) app_tpnt->l_tls_initimage + app_tpnt->loadaddr;
 758                 _dl_debug_early("Relocated TLS initial image from %x to %x (size = %x)\n",
 759                         tmp, app_tpnt->l_tls_initimage, app_tpnt->l_tls_initimage_size);
 760         }
 761 #endif
 762
 763 #ifdef __LDSO_STANDALONE_SUPPORT__
 764         } /* ! ldso standalone mode */
 765 #endif
 766
 767 #ifdef __SUPPORT_LD_DEBUG__
 768         _dl_debug = _dl_getenv("LD_DEBUG", envp);
 769         if (_dl_debug) {
 770                 if (_dl_strstr(_dl_debug, "all")) {
 771                         _dl_debug_detail = _dl_debug_move = _dl_debug_symbols
 772                                 = _dl_debug_reloc = _dl_debug_bindings = _dl_debug_nofixups = (void*)1;
 773                 } else {
 774                         _dl_debug_detail   = _dl_strstr(_dl_debug, "detail");
 775                         _dl_debug_move     = _dl_strstr(_dl_debug, "move");
 776                         _dl_debug_symbols  = _dl_strstr(_dl_debug, "sym");
 777                         _dl_debug_reloc    = _dl_strstr(_dl_debug, "reloc");
 778                         _dl_debug_nofixups = _dl_strstr(_dl_debug, "nofix");
 779                         _dl_debug_bindings = _dl_strstr(_dl_debug, "bind");
 780                 }
 781         }
 782
 783         {
 784                 const char *dl_debug_output;
 785
 786                 dl_debug_output = _dl_getenv("LD_DEBUG_OUTPUT", envp);
 787
 788                 if (dl_debug_output) {
 789                         char tmp[22], *tmp1, *filename;
 790                         int len1, len2;
 791
 792                         _dl_memset(tmp, 0, sizeof(tmp));
 793                         tmp1 = _dl_simple_ltoa( tmp, (unsigned long)_dl_getpid());
 794
 795                         len1 = _dl_strlen(dl_debug_output);
 796                         len2 = _dl_strlen(tmp1);
 797
 798                         filename = _dl_malloc(len1 + len2 + 2);
 799
 800                         if (filename) {
 801                                 _dl_strcpy (filename, dl_debug_output);
 802                                 filename[len1] = '.';
 803                                 _dl_strcpy (&filename[len1+1], tmp1);
 804
 805                                 _dl_debug_file = _dl_open(filename, O_WRONLY|O_CREAT, 0644);
 806                                 if (_dl_debug_file < 0) {
 807                                         _dl_debug_file = 2;
 808                                         _dl_dprintf(_dl_debug_file, "can't open file: '%s'\n",filename);
 809                                 }
 810                         }
 811                 }
 812         }
 813 #endif
 814
 815 #ifdef __LDSO_PRELINK_SUPPORT__
 816 {
 817         char *ld_warn = _dl_getenv ("LD_WARN", envp);
 818
 819         if (ld_warn && *ld_warn == '\0')
 820                 _dl_verbose = false;
 821 }
 822         _dl_trace_prelink = _dl_getenv("LD_TRACE_PRELINKING", envp);
 823 #endif
 824
 825         if (_dl_getenv("LD_TRACE_LOADED_OBJECTS", envp) != NULL) {
 826                 trace_loaded_objects++;
 827         }
 828
 829 #ifndef __LDSO_LDD_SUPPORT__
 830         if (trace_loaded_objects) {
 831                 _dl_dprintf(2, "Use the ldd provided by uClibc\n");
 832                 _dl_exit(1);
 833         }
 834 #endif
 835
 836         ldso_mapaddr = (ElfW(Addr)) auxvt[AT_BASE].a_un.a_val;
 837         /*
 838          * OK, fix one more thing - set up debug_addr so it will point
 839          * to our chain.  Later we may need to fill in more fields, but this
 840          * should be enough for now.
 841          */
 842         debug_addr->r_map = (struct link_map *) _dl_loaded_modules;
 843         debug_addr->r_version = 1;
 844         debug_addr->r_ldbase = (ElfW(Addr))
 845                 DL_LOADADDR_BASE(DL_GET_RUN_ADDR(load_addr, ldso_mapaddr));
 846         debug_addr->r_brk = (unsigned long) &_dl_debug_state;
 847         _dl_debug_addr = debug_addr;
 848
 849         /* Do not notify the debugger until the interpreter is in the list */
 850
 851         /* OK, we now have the application in the list, and we have some
 852          * basic stuff in place.  Now search through the list for other shared
 853          * libraries that should be loaded, and insert them on the list in the
 854          * correct order.
 855          */
 856
 857         _dl_map_cache();
 858
 859 #ifdef __LDSO_PRELOAD_ENV_SUPPORT__
 860         if (_dl_preload) {
 861                 char c, *str, *str2;
 862
 863                 str = _dl_preload;
 864                 while (*str == ':' || *str == ' ' || *str == '\t')
 865                         str++;
 866
 867                 while (*str) {
 868                         str2 = str;
 869                         while (*str2 && *str2 != ':' && *str2 != ' ' && *str2 != '\t')
 870                                 str2++;
 871                         c = *str2;
 872                         *str2 = '\0';
 873
 874                         if (!_dl_secure || _dl_strchr(str, '/') == NULL) {
 875                                 _dl_if_debug_dprint("\tfile='%s';  needed by '%s'\n", str, _dl_progname);
 876
 877                                 tpnt1 = _dl_load_shared_library(
 878                                         _dl_secure ? DL_RESOLVE_SECURE : 0,
 879                                         &rpnt, NULL, str, trace_loaded_objects);
 880                                 if (!tpnt1) {
 881 #ifdef __LDSO_LDD_SUPPORT__
 882                                         if (trace_loaded_objects || _dl_trace_prelink)
 883                                                 _dl_dprintf(1, "\t%s => not found\n", str);
 884                                         else
 885 #endif
 886                                         {
 887                                                 _dl_dprintf(2, "%s: library '%s' "
 888                                                         "from LD_PRELOAD can't be preloaded: ignored.\n",
 889                                                         _dl_progname, str);
 890                                         }
 891                                 } else {
 892                                         tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
 893
 894                                         _dl_debug_early("Loading: (%x) %s\n", DL_LOADADDR_BASE(tpnt1->loadaddr), tpnt1->libname);
 895
 896 #ifdef __LDSO_LDD_SUPPORT__
 897                                         if (trace_loaded_objects && !_dl_trace_prelink &&
 898                                             tpnt1->usage_count == 1) {
 899                                                 /* This is a real hack to make
 900                                                  * ldd not print the library
 901                                                  * itself when run on a
 902                                                  * library.
 903                                                  */
 904                                                 if (_dl_strcmp(_dl_progname, str) != 0)
 905                                                         _dl_dprintf(1, "\t%s => %s (%x)\n", str, tpnt1->libname,
 906                                                                     DL_LOADADDR_BASE(tpnt1->loadaddr));
 907                                         }
 908 #endif
 909                                 }
 910                         }
 911
 912                         *str2 = c;
 913                         str = str2;
 914                         while (*str == ':' || *str == ' ' || *str == '\t')
 915                                 str++;
 916                 }
 917         }
 918 #endif /* __LDSO_PRELOAD_ENV_SUPPORT__ */
 919
 920 #ifdef __LDSO_PRELOAD_FILE_SUPPORT__
 921         do {
 922                 char *preload;
 923                 int fd;
 924                 char c, *cp, *cp2;
 925                 struct stat st;
 926
 927                 if (_dl_stat(LDSO_PRELOAD, &st) || st.st_size == 0) {
 928                         break;
 929                 }
 930
 931                 if ((fd = _dl_open(LDSO_PRELOAD, O_RDONLY, 0)) < 0) {
 932                         _dl_dprintf(2, "%s: can't open file '%s'\n",
 933                                     _dl_progname, LDSO_PRELOAD);
 934                         break;
 935                 }
 936
 937                 preload = (caddr_t) _dl_mmap(0, st.st_size + 1,
 938                                              PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
 939                 _dl_close(fd);
 940                 if (preload == (caddr_t) -1) {
 941                         _dl_dprintf(2, "%s:%i: can't map '%s'\n",
 942                                     _dl_progname, __LINE__, LDSO_PRELOAD);
 943                         break;
 944                 }
 945
 946                 /* convert all separators and comments to spaces */
 947                 for (cp = preload; *cp; /*nada */ ) {
 948                         if (*cp == ':' || *cp == '\t' || *cp == '\n') {
 949                                 *cp++ = ' ';
 950                         } else if (*cp == '#') {
 951                                 do {
 952                                         *cp++ = ' ';
 953                                 } while (*cp != '\n' && *cp != '\0');
 954                         } else {
 955                                 cp++;
 956                         }
 957                 }
 958
 959                 /* find start of first library */
 960                 for (cp = preload; *cp && *cp == ' '; cp++)
 961                         /*nada */ ;
 962
 963                 while (*cp) {
 964                         /* find end of library */
 965                         for (cp2 = cp; *cp && *cp != ' '; cp++)
 966                                 /*nada */ ;
 967                         c = *cp;
 968                         *cp = '\0';
 969
 970                         _dl_if_debug_dprint("\tfile='%s';  needed by '%s'\n", cp2, _dl_progname);
 971
 972                         tpnt1 = _dl_load_shared_library(0, &rpnt, NULL, cp2, trace_loaded_objects);
 973                         if (!tpnt1) {
 974 # ifdef __LDSO_LDD_SUPPORT__
 975                                 if (trace_loaded_objects || _dl_trace_prelink)
 976                                         _dl_dprintf(1, "\t%s => not found\n", cp2);
 977                                 else
 978 # endif
 979                                 {
 980                                         _dl_dprintf(2, "%s: can't load library '%s'\n", _dl_progname, cp2);
 981                                         _dl_exit(15);
 982                                 }
 983                         } else {
 984                                 tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
 985
 986                                 _dl_debug_early("Loading: (%x) %s\n", DL_LOADADDR_BASE(tpnt1->loadaddr), tpnt1->libname);
 987
 988 # ifdef __LDSO_LDD_SUPPORT__
 989                                 if (trace_loaded_objects && !_dl_trace_prelink &&
 990                                     tpnt1->usage_count == 1) {
 991                                         _dl_dprintf(1, "\t%s => %s (%x)\n",
 992                                                     cp2, tpnt1->libname,
 993                                                     DL_LOADADDR_BASE(tpnt1->loadaddr));
 994                                 }
 995 # endif
 996                         }
 997
 998                         /* find start of next library */
 999                         *cp = c;
1000                         for ( /*nada */ ; *cp && *cp == ' '; cp++)
1001                                 /*nada */ ;
1002                 }
1003
1004                 _dl_munmap(preload, st.st_size + 1);
1005         } while (0);
1006 #endif /* __LDSO_PRELOAD_FILE_SUPPORT__ */
1007
1008         nlist = 0;
1009         for (tcurr = _dl_loaded_modules; tcurr; tcurr = tcurr->next) {
1010                 ElfW(Dyn) *this_dpnt;
1011
1012                 nlist++;
1013                 for (this_dpnt = (ElfW(Dyn) *) tcurr->dynamic_addr; this_dpnt->d_tag; this_dpnt++) {
1014                         if (this_dpnt->d_tag == DT_NEEDED) {
1015                                 char *name;
1016                                 struct init_fini_list *tmp;
1017
1018                                 lpntstr = (char*) (tcurr->dynamic_info[DT_STRTAB] + this_dpnt->d_un.d_val);
1019                                 name = _dl_get_last_path_component(lpntstr);
1020                                 _dl_if_debug_dprint("\tfile='%s';  needed by '%s'\n", lpntstr, _dl_progname);
1021
1022                                 if (_dl_strcmp(name, UCLIBC_LDSO) == 0) {
1023                                                 if (!ldso_tpnt) {
1024                                                         /* Insert the ld.so only once */
1025                                                         ldso_tpnt = add_ldso(tpnt, load_addr,
1026                                                                                                  ldso_mapaddr, auxvt, rpnt);
1027                                                 }
1028                                                 ldso_tpnt->usage_count++;
1029                                                 tpnt1 = ldso_tpnt;
1030                                 } else
1031                                         tpnt1 = _dl_load_shared_library(0, &rpnt, tcurr, lpntstr, trace_loaded_objects);
1032
1033                                 if (!tpnt1) {
1034 #ifdef __LDSO_LDD_SUPPORT__
1035                                         if (trace_loaded_objects || _dl_trace_prelink) {
1036                                                 _dl_dprintf(1, "\t%s => not found\n", lpntstr);
1037                                                 continue;
1038                                         } else
1039 #endif
1040                                         {
1041                                                 _dl_dprintf(2, "%s: can't load library '%s'\n", _dl_progname, lpntstr);
1042                                                 _dl_exit(16);
1043                                         }
1044                                 }
1045
1046                                 tmp = alloca(sizeof(struct init_fini_list)); /* Allocates on stack, no need to free this memory */
1047                                 tmp->tpnt = tpnt1;
1048                                 tmp->next = tcurr->init_fini;
1049                                 tcurr->init_fini = tmp;
1050
1051                                 tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
1052
1053                                 _dl_debug_early("Loading: (%x) %s\n", DL_LOADADDR_BASE(tpnt1->loadaddr), tpnt1->libname);
1054
1055 #ifdef __LDSO_LDD_SUPPORT__
1056                                 if (trace_loaded_objects && !_dl_trace_prelink &&
1057                                     tpnt1->usage_count == 1) {
1058                                         _dl_dprintf(1, "\t%s => %s (%x)\n",
1059                                                     lpntstr, tpnt1->libname,
1060                                                     DL_LOADADDR_BASE(tpnt1->loadaddr));
1061                                 }
1062 #endif
1063                         }
1064                 }
1065         }
1066         _dl_unmap_cache();
1067
1068         /* Keep track of the number of elements in the global scope */
1069         nscope_elem = nlist;
1070
1071         if (_dl_loaded_modules->libtype == elf_executable) {
1072                 --nlist; /* Exclude the application. */
1073                 tcurr = _dl_loaded_modules->next;
1074         } else
1075                 tcurr = _dl_loaded_modules;
1076         init_fini_list = _dl_malloc(nlist * sizeof(struct elf_resolve *));
1077         i = 0;
1078         for (; tcurr; tcurr = tcurr->next)
1079                 init_fini_list[i++] = tcurr;
1080
1081         /* Sort the INIT/FINI list in dependency order. */
1082         for (tcurr = _dl_loaded_modules->next; tcurr; tcurr = tcurr->next) {
1083                 unsigned int j, k;
1084
1085                 for (j = 0; init_fini_list[j] != tcurr; ++j)
1086                         /* Empty */;
1087                 for (k = j + 1; k < nlist; ++k) {
1088                         struct init_fini_list *runp = init_fini_list[k]->init_fini;
1089
1090                         for (; runp; runp = runp->next) {
1091                                 if (runp->tpnt == tcurr) {
1092                                         struct elf_resolve *here = init_fini_list[k];
1093                                         _dl_if_debug_dprint("Move %s from pos %d to %d in INIT/FINI list\n", here->libname, k, j);
1094                                         for (i = (k - j); i; --i)
1095                                                 init_fini_list[i+j] = init_fini_list[i+j-1];
1096                                         init_fini_list[j] = here;
1097                                         ++j;
1098                                         break;
1099                                 }
1100                         }
1101                 }
1102         }
1103 #ifdef __SUPPORT_LD_DEBUG__
1104         if (_dl_debug) {
1105                 _dl_dprintf(_dl_debug_file, "\nINIT/FINI order and dependencies:\n");
1106                 for (i = 0; i < nlist; i++) {
1107                         struct init_fini_list *tmp;
1108
1109                         _dl_dprintf(_dl_debug_file, "lib: %s has deps:\n",
1110                                     init_fini_list[i]->libname);
1111                         tmp = init_fini_list[i]->init_fini;
1112                         for (; tmp; tmp = tmp->next)
1113                                 _dl_dprintf(_dl_debug_file, " %s ", tmp->tpnt->libname);
1114                         _dl_dprintf(_dl_debug_file, "\n");
1115                 }
1116         }
1117 #endif
1118
1119         /*
1120          * If the program interpreter is not in the module chain, add it.
1121          * This will be required for dlopen to be able to access the internal
1122          * functions in the dynamic linker and to relocate the interpreter
1123          * again once all libs are loaded.
1124          */
1125         if (!ldso_tpnt) {
1126                 tpnt = add_ldso(tpnt, load_addr, ldso_mapaddr, auxvt, rpnt);
1127                 tpnt->usage_count++;
1128                 nscope_elem++;
1129         } else
1130                 tpnt = ldso_tpnt;
1131
1132 #ifdef RERELOCATE_LDSO
1133                 /* Only rerelocate functions for now. */
1134                 tpnt->init_flag = RELOCS_DONE;
1135                 lpnt = (unsigned long *) (tpnt->dynamic_info[DT_PLTGOT]);
1136 # ifdef ALLOW_ZERO_PLTGOT
1137                 if (tpnt->dynamic_info[DT_PLTGOT])
1138 # endif
1139                         INIT_GOT(lpnt, tpnt);
1140 #else
1141                 tpnt->init_flag = RELOCS_DONE | JMP_RELOCS_DONE;
1142 #endif
1143                 tpnt = NULL;
1144
1145         /*
1146          * Allocate the global scope array.
1147          */
1148         scope_elem_list = (struct elf_resolve **) _dl_malloc(nscope_elem * sizeof(struct elf_resolve *));
1149
1150         for (i = 0, tcurr = _dl_loaded_modules; tcurr; tcurr = tcurr->next)
1151                 scope_elem_list[i++] = tcurr;
1152
1153         _dl_loaded_modules->symbol_scope.r_list = scope_elem_list;
1154         _dl_loaded_modules->symbol_scope.r_nlist = nscope_elem;
1155         /*
1156          * The symbol scope of the application, that is the first entry of the
1157          * _dl_loaded_modules list, is just the global scope to be used for the
1158          * symbol lookup.
1159          */
1160         global_scope = &_dl_loaded_modules->symbol_scope;
1161
1162         /* Build the local scope for each loaded modules. */
1163         local_scope = _dl_malloc(nscope_elem * sizeof(struct elf_resolve *));
1164         i = 1;
1165         for (tcurr = _dl_loaded_modules->next; tcurr; tcurr = tcurr->next) {
1166                 unsigned int k;
1167                 cnt = _dl_build_local_scope(local_scope, scope_elem_list[i++]);
1168                 tcurr->symbol_scope.r_list = _dl_malloc(cnt * sizeof(struct elf_resolve *));
1169                 tcurr->symbol_scope.r_nlist = cnt;
1170                 _dl_memcpy (tcurr->symbol_scope.r_list, local_scope, cnt * sizeof (struct elf_resolve *));
1171                 /* Restoring the init_flag.*/
1172                 for (k = 1; k < nscope_elem; k++)
1173                         scope_elem_list[k]->init_flag &= ~DL_RESERVED;
1174         }
1175
1176         _dl_free(local_scope);
1177
1178 #ifdef __LDSO_LDD_SUPPORT__
1179         /* Exit if LD_TRACE_LOADED_OBJECTS is on. */
1180         if (trace_loaded_objects && !_dl_trace_prelink)
1181                 _dl_exit(0);
1182 #endif
1183
1184 #if defined(USE_TLS) && USE_TLS
1185         /* We do not initialize any of the TLS functionality unless any of the
1186          * initial modules uses TLS.  This makes dynamic loading of modules with
1187          * TLS impossible, but to support it requires either eagerly doing setup
1188          * now or lazily doing it later.  Doing it now makes us incompatible with
1189          * an old kernel that can't perform TLS_INIT_TP, even if no TLS is ever
1190          * used.  Trying to do it lazily is too hairy to try when there could be
1191          * multiple threads (from a non-TLS-using libpthread).  */
1192         bool was_tls_init_tp_called = tls_init_tp_called;
1193         if (tcbp == NULL) {
1194                 _dl_debug_early("Calling init_tls()!\n");
1195                 tcbp = init_tls ();
1196         }
1197 #endif
1198 #ifdef __UCLIBC_HAS_SSP__
1199         /* Set up the stack checker's canary.  */
1200         stack_chk_guard = _dl_setup_stack_chk_guard ();
1201 # ifdef THREAD_SET_STACK_GUARD
1202         THREAD_SET_STACK_GUARD (stack_chk_guard);
1203 # else
1204         __stack_chk_guard = stack_chk_guard;
1205 # endif
1206 # ifdef __UCLIBC_HAS_SSP_COMPAT__
1207         __guard = stack_chk_guard;
1208 # endif
1209 #endif
1210
1211 #ifdef __LDSO_PRELINK_SUPPORT__
1212         if (_dl_trace_prelink) {
1213
1214                 unsigned int nscope_trace = ldso_tpnt ? nscope_elem : (nscope_elem - 1);
1215
1216                 for (i = 0; i < nscope_trace; i++)
1217                         trace_objects(scope_elem_list[i],
1218                                 _dl_get_last_path_component(scope_elem_list[i]->libname));
1219
1220                 if (_dl_verbose)
1221                         /* Warn about undefined symbols. */
1222                         if (_dl_symbol_tables)
1223                                 if (_dl_fixup(_dl_symbol_tables, global_scope, unlazy))
1224                                         _dl_exit(-1);
1225                 _dl_exit(0);
1226         }
1227
1228         if (_dl_loaded_modules->dynamic_info[DT_GNU_LIBLIST_IDX]) {
1229                 ElfW(Lib) *liblist, *liblistend;
1230                 struct elf_resolve **r_list, **r_listend, *l;
1231                 const char *strtab = (const char *)_dl_loaded_modules->dynamic_info[DT_STRTAB];
1232
1233                 _dl_assert (_dl_loaded_modules->dynamic_info[DT_GNU_LIBLISTSZ_IDX] != 0);
1234                 liblist = (ElfW(Lib) *) _dl_loaded_modules->dynamic_info[DT_GNU_LIBLIST_IDX];
1235                 liblistend = (ElfW(Lib) *)
1236                 ((char *) liblist + _dl_loaded_modules->dynamic_info[DT_GNU_LIBLISTSZ_IDX]);
1237                 r_list = _dl_loaded_modules->symbol_scope.r_list;
1238                 r_listend = r_list + nscope_elem;
1239
1240                 for (; r_list < r_listend && liblist < liblistend; r_list++) {
1241                         l = *r_list;
1242
1243                         if (l == _dl_loaded_modules)
1244                                 continue;
1245
1246                         /* If the library is not mapped where it should, fail.  */
1247                         if (l->loadaddr)
1248                                 break;
1249
1250                         /* Next, check if checksum matches.  */
1251                         if (l->dynamic_info[DT_CHECKSUM_IDX] == 0 ||
1252                                 l->dynamic_info[DT_CHECKSUM_IDX] != liblist->l_checksum)
1253                                 break;
1254
1255                         if (l->dynamic_info[DT_GNU_PRELINKED_IDX] == 0 ||
1256                                 (l->dynamic_info[DT_GNU_PRELINKED_IDX] != liblist->l_time_stamp))
1257                                 break;
1258
1259                         if (_dl_strcmp(strtab + liblist->l_name, _dl_get_last_path_component(l->libname)) != 0)
1260                                 break;
1261
1262                         ++liblist;
1263                 }
1264
1265
1266                 if (r_list == r_listend && liblist == liblistend)
1267                         prelinked = true;
1268
1269         }
1270
1271         _dl_debug_early ("\nprelink checking: %s\n", prelinked ? "ok" : "failed");
1272
1273         if (prelinked) {
1274                 if (_dl_loaded_modules->dynamic_info[DT_GNU_CONFLICT_IDX]) {
1275                         ELF_RELOC *conflict;
1276                         unsigned long conflict_size;
1277
1278                         _dl_assert (_dl_loaded_modules->dynamic_info[DT_GNU_CONFLICTSZ_IDX] != 0);
1279                         conflict = (ELF_RELOC *) _dl_loaded_modules->dynamic_info[DT_GNU_CONFLICT_IDX];
1280                         conflict_size = _dl_loaded_modules->dynamic_info[DT_GNU_CONFLICTSZ_IDX];
1281                         _dl_parse_relocation_information(_dl_symbol_tables, global_scope,
1282                                 (unsigned long) conflict, conflict_size);
1283                 }
1284
1285                 /* Mark all the objects so we know they have been already relocated.  */
1286                 for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
1287                         tpnt->init_flag |= RELOCS_DONE;
1288                         if (tpnt->relro_size)
1289                                 _dl_protect_relro (tpnt);
1290                 }
1291         } else
1292 #endif
1293
1294         {
1295
1296         _dl_debug_early("Beginning relocation fixups\n");
1297
1298 #ifdef __mips__
1299         /*
1300          * Relocation of the GOT entries for MIPS have to be done
1301          * after all the libraries have been loaded.
1302          */
1303         _dl_perform_mips_global_got_relocations(_dl_loaded_modules, !unlazy);
1304 #endif
1305
1306         /*
1307          * OK, now all of the kids are tucked into bed in their proper
1308          * addresses.  Now we go through and look for REL and RELA records that
1309          * indicate fixups to the GOT tables.  We need to do this in reverse
1310          * order so that COPY directives work correctly.
1311          */
1312         if (_dl_symbol_tables)
1313                 if (_dl_fixup(_dl_symbol_tables, global_scope, unlazy))
1314                         _dl_exit(-1);
1315
1316         for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
1317                 if (tpnt->relro_size)
1318                         _dl_protect_relro (tpnt);
1319         }
1320         } /* not prelinked */
1321
1322 #if defined(USE_TLS) && USE_TLS
1323         if (!was_tls_init_tp_called && _dl_tls_max_dtv_idx > 0)
1324                 ++_dl_tls_generation;
1325
1326         _dl_debug_early("Calling _dl_allocate_tls_init()!\n");
1327
1328         /* Now that we have completed relocation, the initializer data
1329            for the TLS blocks has its final values and we can copy them
1330            into the main thread's TLS area, which we allocated above.  */
1331         _dl_allocate_tls_init (tcbp);
1332
1333         /* And finally install it for the main thread.  If ld.so itself uses
1334            TLS we know the thread pointer was initialized earlier.  */
1335         if (! tls_init_tp_called) {
1336                 const char *lossage = (char *) TLS_INIT_TP (tcbp, USE___THREAD);
1337                 if (__builtin_expect (lossage != NULL, 0)) {
1338                         _dl_debug_early("cannot set up thread-local storage: %s\n", lossage);
1339                         _dl_exit(30);
1340                 }
1341         }
1342 #endif /* USE_TLS */
1343
1344         /* OK, at this point things are pretty much ready to run.  Now we need
1345          * to touch up a few items that are required, and then we can let the
1346          * user application have at it.  Note that the dynamic linker itself
1347          * is not guaranteed to be fully dynamicly linked if we are using
1348          * ld.so.1, so we have to look up each symbol individually.
1349          */
1350
1351         _dl_envp = (unsigned long *) (intptr_t) _dl_find_hash(__C_SYMBOL_PREFIX__ "__environ", global_scope, NULL, 0, NULL);
1352         if (_dl_envp)
1353                 *_dl_envp = (unsigned long) envp;
1354
1355 #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
1356         {
1357                 unsigned int j;
1358                 ElfW(Phdr) *myppnt;
1359
1360                 /* We had to set the protections of all pages to R/W for
1361                  * dynamic linking.  Set text pages back to R/O.
1362                  */
1363                 for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
1364                         for (myppnt = tpnt->ppnt, j = 0; j < tpnt->n_phent; j++, myppnt++) {
1365                                 if (myppnt->p_type == PT_LOAD && !(myppnt->p_flags & PF_W) && tpnt->dynamic_info[DT_TEXTREL]) {
1366                                         _dl_mprotect((void *) (DL_RELOC_ADDR(tpnt->loadaddr, myppnt->p_vaddr) & PAGE_ALIGN),
1367                                                         (myppnt->p_vaddr & ADDR_ALIGN) + (unsigned long) myppnt->p_filesz, LXFLAGS(myppnt->p_flags));
1368                                 }
1369                         }
1370                 }
1371
1372         }
1373 #endif
1374         /* Notify the debugger we have added some objects. */
1375         _dl_debug_addr->r_state = RT_ADD;
1376         _dl_debug_state();
1377
1378         /* Run pre-initialization functions for the executable.  */
1379         _dl_run_array_forward(_dl_loaded_modules->dynamic_info[DT_PREINIT_ARRAY],
1380                               _dl_loaded_modules->dynamic_info[DT_PREINIT_ARRAYSZ],
1381                               _dl_loaded_modules->loadaddr);
1382
1383         /* Run initialization functions for loaded objects.  For the
1384            main executable, they will be run from __uClibc_main.  */
1385         for (i = nlist; i; --i) {
1386                 tpnt = init_fini_list[i-1];
1387                 tpnt->init_fini = NULL; /* Clear, since alloca was used */
1388                 if (tpnt->init_flag & INIT_FUNCS_CALLED)
1389                         continue;
1390                 tpnt->init_flag |= INIT_FUNCS_CALLED;
1391
1392                 if (tpnt->dynamic_info[DT_INIT]) {
1393                         void (*dl_elf_func) (void);
1394
1395                         dl_elf_func = (void (*)(void)) DL_RELOC_ADDR(tpnt->loadaddr, tpnt->dynamic_info[DT_INIT]);
1396
1397                         _dl_if_debug_dprint("calling INIT: %s\n\n", tpnt->libname);
1398
1399                         DL_CALL_FUNC_AT_ADDR (dl_elf_func, tpnt->loadaddr, (void(*)(void)));
1400                 }
1401
1402                 _dl_run_init_array(tpnt);
1403         }
1404
1405         /* Find the real malloc function and make ldso functions use that from now on */
1406         _dl_malloc_function = (void* (*)(size_t)) (intptr_t) _dl_find_hash(__C_SYMBOL_PREFIX__ "malloc",
1407                         global_scope, NULL, ELF_RTYPE_CLASS_PLT, NULL);
1408
1409 #if defined(USE_TLS) && USE_TLS
1410         /* Find the real functions and make ldso functions use them from now on */
1411         _dl_calloc_function = (void* (*)(size_t, size_t)) (intptr_t)
1412                 _dl_find_hash(__C_SYMBOL_PREFIX__ "calloc", global_scope, NULL, ELF_RTYPE_CLASS_PLT, NULL);
1413
1414         _dl_realloc_function = (void* (*)(void *, size_t)) (intptr_t)
1415                 _dl_find_hash(__C_SYMBOL_PREFIX__ "realloc", global_scope, NULL, ELF_RTYPE_CLASS_PLT, NULL);
1416
1417         _dl_free_function = (void (*)(void *)) (intptr_t)
1418                 _dl_find_hash(__C_SYMBOL_PREFIX__ "free", global_scope, NULL, ELF_RTYPE_CLASS_PLT, NULL);
1419
1420         _dl_memalign_function = (void* (*)(size_t, size_t)) (intptr_t)
1421                 _dl_find_hash(__C_SYMBOL_PREFIX__ "memalign", global_scope, NULL, ELF_RTYPE_CLASS_PLT, NULL);
1422
1423 #endif
1424
1425         /* Notify the debugger that all objects are now mapped in.  */
1426         _dl_debug_addr->r_state = RT_CONSISTENT;
1427         _dl_debug_state();
1428
1429 #ifdef __LDSO_STANDALONE_SUPPORT__
1430         if (_start == (void *) auxvt[AT_ENTRY].a_un.a_val)
1431                 return (void *) app_tpnt->l_entry;
1432         else
1433 #endif
1434                 return (void *) auxvt[AT_ENTRY].a_un.a_val;
1435 }
1436
1437 #include "dl-hash.c"
1438 #include "dl-elf.c"