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) 2000-2004 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 /* Pull in the value of _dl_progname */
  42 #include LDSO_ELFINTERP
  43
  44 /* Global variables used within the shared library loader */
  45 char *_dl_library_path         = 0;     /* Where we look for libraries */
  46 char *_dl_preload              = 0;     /* Things to be loaded before the libs */
  47 char *_dl_ldsopath             = 0;     /* Location of the shared lib loader */
  48 int _dl_secure                 = 1;     /* Are we dealing with setuid stuff? */
  49 int _dl_errno                  = 0;     /* We can't use the real errno in ldso */
  50 size_t _dl_pagesize            = 0;     /* Store the page size for use later */
  51 struct r_debug *_dl_debug_addr = NULL;  /* Used to communicate with the gdb debugger */
  52 void *(*_dl_malloc_function) (size_t size) = NULL;
  53
  54 #ifdef __SUPPORT_LD_DEBUG__
  55 char *_dl_debug           = 0;
  56 char *_dl_debug_symbols   = 0;
  57 char *_dl_debug_move      = 0;
  58 char *_dl_debug_reloc     = 0;
  59 char *_dl_debug_detail    = 0;
  60 char *_dl_debug_nofixups  = 0;
  61 char *_dl_debug_bindings  = 0;
  62 int   _dl_debug_file      = 2;
  63 #endif
  64
  65 /* Needed for standalone execution. */
  66 unsigned long attribute_hidden _dl_skip_args = 0;
  67 const char *_dl_progname = UCLIBC_LDSO;      /* The name of the executable being run */
  68 #include "dl-startup.c"
  69 /* Forward function declarations */
  70 static int _dl_suid_ok(void);
  71
  72 /*
  73  * This stub function is used by some debuggers.  The idea is that they
  74  * can set an internal breakpoint on it, so that we are notified when the
  75  * address mapping is changed in some way.
  76  */
  77 void _dl_debug_state(void);
  78 void _dl_debug_state()
  79 {
  80 }
  81
  82 static unsigned char *_dl_malloc_addr = 0;      /* Lets _dl_malloc use the already allocated memory page */
  83 static unsigned char *_dl_mmap_zero   = 0;      /* Also used by _dl_malloc */
  84
  85 static struct elf_resolve **init_fini_list;
  86 static unsigned int nlist; /* # items in init_fini_list */
  87 extern void _start(void);
  88
  89 #ifdef __UCLIBC_HAS_SSP__
  90 # include <dl-osinfo.h>
  91 uintptr_t stack_chk_guard;
  92 # ifndef THREAD_SET_STACK_GUARD
  93 /* Only exported for architectures that don't store the stack guard canary
  94  * in local thread area.  */
  95 uintptr_t __stack_chk_guard attribute_relro;
  96 #  ifdef __UCLIBC_HAS_SSP_COMPAT__
  97 strong_alias(__stack_chk_guard,__guard)
  98 #  endif
  99 # elif __UCLIBC_HAS_SSP_COMPAT__
 100 uintptr_t __guard attribute_relro;
 101 # endif
 102 #endif
 103
 104 static void _dl_run_array_forward(unsigned long array, unsigned long size,
 105                                   ElfW(Addr) loadaddr)
 106 {
 107         if (array != 0) {
 108                 unsigned int j;
 109                 unsigned int jm;
 110                 ElfW(Addr) *addrs;
 111                 jm = size / sizeof (ElfW(Addr));
 112                 addrs = (ElfW(Addr) *) (array + loadaddr);
 113                 for (j = 0; j < jm; ++j) {
 114                         void (*dl_elf_func) (void);
 115                         dl_elf_func = (void (*)(void)) (intptr_t) addrs[j];
 116                         (*dl_elf_func) ();
 117                 }
 118         }
 119 }
 120
 121 void _dl_run_init_array(struct elf_resolve *tpnt);
 122 void _dl_run_init_array(struct elf_resolve *tpnt)
 123 {
 124         _dl_run_array_forward(tpnt->dynamic_info[DT_INIT_ARRAY],
 125                               tpnt->dynamic_info[DT_INIT_ARRAYSZ],
 126                               tpnt->loadaddr);
 127 }
 128
 129 void _dl_app_init_array(void);
 130 void _dl_app_init_array(void)
 131 {
 132         _dl_run_init_array(_dl_loaded_modules);
 133 }
 134
 135 void _dl_run_fini_array(struct elf_resolve *tpnt);
 136 void _dl_run_fini_array(struct elf_resolve *tpnt)
 137 {
 138         if (tpnt->dynamic_info[DT_FINI_ARRAY]) {
 139                 ElfW(Addr) *array = (ElfW(Addr) *) (tpnt->loadaddr + tpnt->dynamic_info[DT_FINI_ARRAY]);
 140                 unsigned int i = (tpnt->dynamic_info[DT_FINI_ARRAYSZ] / sizeof(ElfW(Addr)));
 141                 while (i-- > 0) {
 142                         void (*dl_elf_func) (void);
 143                         dl_elf_func = (void (*)(void)) (intptr_t) array[i];
 144                         (*dl_elf_func) ();
 145                 }
 146         }
 147 }
 148
 149 void _dl_app_fini_array(void);
 150 void _dl_app_fini_array(void)
 151 {
 152         _dl_run_fini_array(_dl_loaded_modules);
 153 }
 154
 155 static void __attribute__ ((destructor)) __attribute_used__ _dl_fini(void)
 156 {
 157         int i;
 158         struct elf_resolve * tpnt;
 159
 160         for (i = 0; i < nlist; ++i) {
 161                 tpnt = init_fini_list[i];
 162                 if (tpnt->init_flag & FINI_FUNCS_CALLED)
 163                         continue;
 164                 tpnt->init_flag |= FINI_FUNCS_CALLED;
 165                 _dl_run_fini_array(tpnt);
 166                 if (tpnt->dynamic_info[DT_FINI]) {
 167                         void (*dl_elf_func) (void);
 168
 169                         dl_elf_func = (void (*)(void)) (intptr_t) (tpnt->loadaddr + tpnt->dynamic_info[DT_FINI]);
 170                         _dl_if_debug_dprint("\ncalling FINI: %s\n\n", tpnt->libname);
 171                         (*dl_elf_func) ();
 172                 }
 173         }
 174 }
 175
 176 void _dl_get_ready_to_run(struct elf_resolve *tpnt, unsigned long load_addr,
 177                           ElfW(auxv_t) auxvt[AT_EGID + 1], char **envp,
 178                           char **argv)
 179 {
 180         ElfW(Phdr) *ppnt;
 181         ElfW(Dyn) *dpnt;
 182         char *lpntstr;
 183         unsigned int i;
 184         int unlazy = 0, trace_loaded_objects = 0;
 185         struct dyn_elf *rpnt;
 186         struct elf_resolve *tcurr;
 187         struct elf_resolve *tpnt1;
 188         struct elf_resolve app_tpnt_tmp;
 189         struct elf_resolve *app_tpnt = &app_tpnt_tmp;
 190         struct r_debug *debug_addr;
 191         unsigned long *lpnt;
 192         unsigned long *_dl_envp;                /* The environment address */
 193         ElfW(Addr) relro_addr = 0;
 194         size_t relro_size = 0;
 195
 196         /* Wahoo!!! We managed to make a function call!  Get malloc
 197          * setup so we can use _dl_dprintf() to print debug noise
 198          * instead of the SEND_STDERR macros used in dl-startup.c */
 199
 200         _dl_memset(app_tpnt, 0x00, sizeof(*app_tpnt));
 201
 202         /* Store the page size for later use */
 203         _dl_pagesize = (auxvt[AT_PAGESZ].a_un.a_val) ? (size_t) auxvt[AT_PAGESZ].a_un.a_val : PAGE_SIZE;
 204         /* Make it so _dl_malloc can use the page of memory we have already
 205          * allocated.  We shouldn't need to grab any more memory.  This must
 206          * be first since things like _dl_dprintf() use _dl_malloc()...
 207          */
 208         _dl_malloc_addr = (unsigned char *)_dl_pagesize;
 209         _dl_mmap_zero = 0;
 210
 211         /* Wahoo!!! */
 212         _dl_debug_early("Cool, ldso survived making function calls\n");
 213
 214         /* Now we have done the mandatory linking of some things.  We are now
 215          * free to start using global variables, since these things have all
 216          * been fixed up by now.  Still no function calls outside of this
 217          * library, since the dynamic resolver is not yet ready.
 218          */
 219         if (argv[0]) {
 220                 _dl_progname = argv[0];
 221         }
 222
 223         if (_start == (void *) auxvt[AT_ENTRY].a_un.a_val) {
 224                 _dl_dprintf(_dl_debug_file, "Standalone execution is not supported yet\n");
 225                 _dl_exit(1);
 226         }
 227
 228         /* Start to build the tables of the modules that are required for
 229          * this beast to run.  We start with the basic executable, and then
 230          * go from there.  Eventually we will run across ourself, and we
 231          * will need to properly deal with that as well.
 232          */
 233         rpnt = NULL;
 234         if (_dl_getenv("LD_BIND_NOW", envp))
 235                 unlazy = RTLD_NOW;
 236
 237         /* Now we need to figure out what kind of options are selected.
 238          * Note that for SUID programs we ignore the settings in
 239          * LD_LIBRARY_PATH.
 240          */
 241         if ((auxvt[AT_UID].a_un.a_val == (size_t)-1 && _dl_suid_ok()) ||
 242             (auxvt[AT_UID].a_un.a_val != (size_t)-1 &&
 243              auxvt[AT_UID].a_un.a_val == auxvt[AT_EUID].a_un.a_val &&
 244              auxvt[AT_GID].a_un.a_val == auxvt[AT_EGID].a_un.a_val)) {
 245                 _dl_secure = 0;
 246                 _dl_preload = _dl_getenv("LD_PRELOAD", envp);
 247                 _dl_library_path = _dl_getenv("LD_LIBRARY_PATH", envp);
 248         } else {
 249                 static const char unsecure_envvars[] =
 250 #ifdef EXTRA_UNSECURE_ENVVARS
 251                         EXTRA_UNSECURE_ENVVARS
 252 #endif
 253                         UNSECURE_ENVVARS;
 254                 const char *nextp;
 255                 _dl_secure = 1;
 256
 257                 nextp = unsecure_envvars;
 258                 do {
 259                         _dl_unsetenv (nextp, envp);
 260                         /* We could use rawmemchr but this need not be fast.  */
 261                         nextp = (char *) _dl_strchr(nextp, '\0') + 1;
 262                 } while (*nextp != '\0');
 263                 _dl_preload = NULL;
 264                 _dl_library_path = NULL;
 265                 /* SUID binaries can be exploited if they do LAZY relocation. */
 266                 unlazy = RTLD_NOW;
 267         }
 268
 269         /* sjhill: your TLS init should go before this */
 270 #ifdef __UCLIBC_HAS_SSP__
 271         /* Set up the stack checker's canary.  */
 272         stack_chk_guard = _dl_setup_stack_chk_guard ();
 273 # ifdef THREAD_SET_STACK_GUARD
 274         THREAD_SET_STACK_GUARD (stack_chk_guard);
 275 #  ifdef __UCLIBC_HAS_SSP_COMPAT__
 276         __guard = stack_chk_guard;
 277 #  endif
 278 # else
 279         __stack_chk_guard = stack_chk_guard;
 280 # endif
 281 #endif
 282
 283         /* At this point we are now free to examine the user application,
 284          * and figure out which libraries are supposed to be called.  Until
 285          * we have this list, we will not be completely ready for dynamic
 286          * linking.
 287          */
 288
 289         /* Find the runtime load address of the main executable.  This may be
 290          * different from what the ELF header says for ET_DYN/PIE executables.
 291          */
 292         {
 293                 unsigned int idx;
 294                 ElfW(Phdr) *phdr = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
 295
 296                 for (idx = 0; idx < auxvt[AT_PHNUM].a_un.a_val; idx++, phdr++)
 297                         if (phdr->p_type == PT_PHDR) {
 298                                 app_tpnt->loadaddr = (ElfW(Addr)) (auxvt[AT_PHDR].a_un.a_val - phdr->p_vaddr);
 299                                 break;
 300                         }
 301
 302                 if (app_tpnt->loadaddr)
 303                         _dl_debug_early("Position Independent Executable: "
 304                                         "app_tpnt->loadaddr=%x\n", app_tpnt->loadaddr);
 305         }
 306
 307         /*
 308          * This is used by gdb to locate the chain of shared libraries that are
 309          * currently loaded.
 310          */
 311         debug_addr = _dl_malloc(sizeof(struct r_debug));
 312         _dl_memset(debug_addr, 0, sizeof(struct r_debug));
 313
 314         ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
 315         for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++) {
 316                 if (ppnt->p_type == PT_GNU_RELRO) {
 317                         relro_addr = ppnt->p_vaddr;
 318                         relro_size = ppnt->p_memsz;
 319                 }
 320                 if (ppnt->p_type == PT_DYNAMIC) {
 321                         dpnt = (ElfW(Dyn) *) (ppnt->p_vaddr + app_tpnt->loadaddr);
 322                         _dl_parse_dynamic_info(dpnt, app_tpnt->dynamic_info, debug_addr, app_tpnt->loadaddr);
 323 #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
 324                         /* Ugly, ugly.  We need to call mprotect to change the
 325                          * protection of the text pages so that we can do the
 326                          * dynamic linking.  We can set the protection back
 327                          * again once we are done.
 328                          */
 329                         _dl_debug_early("calling mprotect on the application program\n");
 330                         /* Now cover the application program. */
 331                         if (app_tpnt->dynamic_info[DT_TEXTREL]) {
 332                                 ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
 333                                 for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++) {
 334                                         if (ppnt->p_type == PT_LOAD && !(ppnt->p_flags & PF_W))
 335                                                 _dl_mprotect((void *) ((ppnt->p_vaddr + app_tpnt->loadaddr) & PAGE_ALIGN),
 336                                                              ((ppnt->p_vaddr + app_tpnt->loadaddr) & ADDR_ALIGN) +
 337                                                              (unsigned long) ppnt->p_filesz,
 338                                                              PROT_READ | PROT_WRITE | PROT_EXEC);
 339                                 }
 340                         }
 341 #endif
 342
 343 #ifndef ALLOW_ZERO_PLTGOT
 344                         /* make sure it's really there. */
 345                         if (app_tpnt->dynamic_info[DT_PLTGOT] == 0)
 346                                 continue;
 347 #endif
 348                         /* OK, we have what we need - slip this one into the list. */
 349                         app_tpnt = _dl_add_elf_hash_table(_dl_progname, (char *)app_tpnt->loadaddr,
 350                                         app_tpnt->dynamic_info, ppnt->p_vaddr + app_tpnt->loadaddr, ppnt->p_filesz);
 351                         _dl_loaded_modules->libtype = elf_executable;
 352                         _dl_loaded_modules->ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
 353                         _dl_loaded_modules->n_phent = auxvt[AT_PHNUM].a_un.a_val;
 354                         _dl_symbol_tables = rpnt = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
 355                         _dl_memset(rpnt, 0, sizeof(struct dyn_elf));
 356                         rpnt->dyn = _dl_loaded_modules;
 357                         app_tpnt->rtld_flags = unlazy | RTLD_GLOBAL;
 358                         app_tpnt->usage_count++;
 359                         app_tpnt->symbol_scope = _dl_symbol_tables;
 360                         lpnt = (unsigned long *) (app_tpnt->dynamic_info[DT_PLTGOT]);
 361 #ifdef ALLOW_ZERO_PLTGOT
 362                         if (lpnt)
 363 #endif
 364                                 INIT_GOT(lpnt, _dl_loaded_modules);
 365                 }
 366
 367                 /* OK, fill this in - we did not have this before */
 368                 if (ppnt->p_type == PT_INTERP) {
 369                         char *ptmp;
 370
 371                         tpnt->libname = (char *) ppnt->p_vaddr + app_tpnt->loadaddr;
 372
 373                         /* Store the path where the shared lib loader was found
 374                          * for later use
 375                          */
 376                         _dl_ldsopath = _dl_strdup(tpnt->libname);
 377                         ptmp = _dl_strrchr(_dl_ldsopath, '/');
 378                         if (ptmp != _dl_ldsopath)
 379                                 *ptmp = '\0';
 380
 381                         _dl_debug_early("Lib Loader: (%x) %s\n", tpnt->loadaddr, tpnt->libname);
 382                 }
 383         }
 384         app_tpnt->relro_addr = relro_addr;
 385         app_tpnt->relro_size = relro_size;
 386
 387 #ifdef __SUPPORT_LD_DEBUG__
 388         _dl_debug = _dl_getenv("LD_DEBUG", envp);
 389         if (_dl_debug) {
 390                 if (_dl_strstr(_dl_debug, "all")) {
 391                         _dl_debug_detail = _dl_debug_move = _dl_debug_symbols
 392                                 = _dl_debug_reloc = _dl_debug_bindings = _dl_debug_nofixups = (void*)1;
 393                 } else {
 394                         _dl_debug_detail   = _dl_strstr(_dl_debug, "detail");
 395                         _dl_debug_move     = _dl_strstr(_dl_debug, "move");
 396                         _dl_debug_symbols  = _dl_strstr(_dl_debug, "sym");
 397                         _dl_debug_reloc    = _dl_strstr(_dl_debug, "reloc");
 398                         _dl_debug_nofixups = _dl_strstr(_dl_debug, "nofix");
 399                         _dl_debug_bindings = _dl_strstr(_dl_debug, "bind");
 400                 }
 401         }
 402
 403         {
 404                 const char *dl_debug_output;
 405
 406                 dl_debug_output = _dl_getenv("LD_DEBUG_OUTPUT", envp);
 407
 408                 if (dl_debug_output) {
 409                         char tmp[22], *tmp1, *filename;
 410                         int len1, len2;
 411
 412                         _dl_memset(tmp, 0, sizeof(tmp));
 413                         tmp1 = _dl_simple_ltoa( tmp, (unsigned long)_dl_getpid());
 414
 415                         len1 = _dl_strlen(dl_debug_output);
 416                         len2 = _dl_strlen(tmp1);
 417
 418                         filename = _dl_malloc(len1+len2+2);
 419
 420                         if (filename) {
 421                                 _dl_strcpy (filename, dl_debug_output);
 422                                 filename[len1] = '.';
 423                                 _dl_strcpy (&filename[len1+1], tmp1);
 424
 425                                 _dl_debug_file= _dl_open(filename, O_WRONLY|O_CREAT, 0644);
 426                                 if (_dl_debug_file < 0) {
 427                                         _dl_debug_file = 2;
 428                                         _dl_dprintf(_dl_debug_file, "can't open file: '%s'\n",filename);
 429                                 }
 430                         }
 431                 }
 432         }
 433 #endif
 434
 435         if (_dl_getenv("LD_TRACE_LOADED_OBJECTS", envp) != NULL) {
 436                 trace_loaded_objects++;
 437         }
 438
 439 #ifndef __LDSO_LDD_SUPPORT__
 440         if (trace_loaded_objects) {
 441                 _dl_dprintf(_dl_debug_file, "Use the ldd provided by uClibc\n");
 442                 _dl_exit(1);
 443         }
 444 #endif
 445
 446         /*
 447          * OK, fix one more thing - set up debug_addr so it will point
 448          * to our chain.  Later we may need to fill in more fields, but this
 449          * should be enough for now.
 450          */
 451         debug_addr->r_map = (struct link_map *) _dl_loaded_modules;
 452         debug_addr->r_version = 1;
 453         debug_addr->r_ldbase = load_addr;
 454         debug_addr->r_brk = (unsigned long) &_dl_debug_state;
 455         _dl_debug_addr = debug_addr;
 456
 457         /* Notify the debugger we are in a consistant state */
 458         _dl_debug_addr->r_state = RT_CONSISTENT;
 459         _dl_debug_state();
 460
 461         /* OK, we now have the application in the list, and we have some
 462          * basic stuff in place.  Now search through the list for other shared
 463          * libraries that should be loaded, and insert them on the list in the
 464          * correct order.
 465          */
 466
 467         _dl_map_cache();
 468
 469         if (_dl_preload) {
 470                 char c, *str, *str2;
 471
 472                 str = _dl_preload;
 473                 while (*str == ':' || *str == ' ' || *str == '\t')
 474                         str++;
 475
 476                 while (*str) {
 477                         str2 = str;
 478                         while (*str2 && *str2 != ':' && *str2 != ' ' && *str2 != '\t')
 479                                 str2++;
 480                         c = *str2;
 481                         *str2 = '\0';
 482
 483                         if (!_dl_secure || _dl_strchr(str, '/') == NULL) {
 484                                 _dl_if_debug_dprint("\tfile='%s';  needed by '%s'\n", str, _dl_progname);
 485
 486                                 tpnt1 = _dl_load_shared_library(_dl_secure, &rpnt, NULL, str, trace_loaded_objects);
 487                                 if (!tpnt1) {
 488 #ifdef __LDSO_LDD_SUPPORT__
 489                                         if (trace_loaded_objects)
 490                                                 _dl_dprintf(1, "\t%s => not found\n", str);
 491                                         else
 492 #endif
 493                                         {
 494                                                 _dl_dprintf(_dl_debug_file, "%s: can't load " "library '%s'\n", _dl_progname, str);
 495                                                 _dl_exit(15);
 496                                         }
 497                                 } else {
 498                                         tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
 499
 500                                         _dl_debug_early("Loading: (%x) %s\n", tpnt1->loadaddr, tpnt1->libname);
 501
 502 #ifdef __LDSO_LDD_SUPPORT__
 503                                         if (trace_loaded_objects &&
 504                                             tpnt1->usage_count == 1) {
 505                                                 /* This is a real hack to make
 506                                                  * ldd not print the library
 507                                                  * itself when run on a
 508                                                  * library.
 509                                                  */
 510                                                 if (_dl_strcmp(_dl_progname, str) != 0)
 511                                                         _dl_dprintf(1, "\t%s => %s (%x)\n", str, tpnt1->libname,
 512                                                                     tpnt1->loadaddr);
 513                                         }
 514 #endif
 515                                 }
 516                         }
 517
 518                         *str2 = c;
 519                         str = str2;
 520                         while (*str == ':' || *str == ' ' || *str == '\t')
 521                                 str++;
 522                 }
 523         }
 524
 525 #ifdef __LDSO_PRELOAD_FILE_SUPPORT__
 526         do {
 527                 struct stat st;
 528                 char *preload;
 529                 int fd;
 530                 char c, *cp, *cp2;
 531
 532                 if (_dl_stat(LDSO_PRELOAD, &st) || st.st_size == 0) {
 533                         break;
 534                 }
 535
 536                 if ((fd = _dl_open(LDSO_PRELOAD, O_RDONLY, 0)) < 0) {
 537                         _dl_dprintf(_dl_debug_file, "%s: can't open file '%s'\n",
 538                                     _dl_progname, LDSO_PRELOAD);
 539                         break;
 540                 }
 541
 542                 preload = (caddr_t) _dl_mmap(0, st.st_size + 1,
 543                                              PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
 544                 _dl_close(fd);
 545                 if (preload == (caddr_t) -1) {
 546                         _dl_dprintf(_dl_debug_file, "%s:%i: can't map '%s'\n",
 547                                     _dl_progname, __LINE__, LDSO_PRELOAD);
 548                         break;
 549                 }
 550
 551                 /* convert all separators and comments to spaces */
 552                 for (cp = preload; *cp; /*nada */ ) {
 553                         if (*cp == ':' || *cp == '\t' || *cp == '\n') {
 554                                 *cp++ = ' ';
 555                         } else if (*cp == '#') {
 556                                 do {
 557                                         *cp++ = ' ';
 558                                 } while (*cp != '\n' && *cp != '\0');
 559                         } else {
 560                                 cp++;
 561                         }
 562                 }
 563
 564                 /* find start of first library */
 565                 for (cp = preload; *cp && *cp == ' '; cp++)
 566                         /*nada */ ;
 567
 568                 while (*cp) {
 569                         /* find end of library */
 570                         for (cp2 = cp; *cp && *cp != ' '; cp++)
 571                                 /*nada */ ;
 572                         c = *cp;
 573                         *cp = '\0';
 574
 575                         _dl_if_debug_dprint("\tfile='%s';  needed by '%s'\n", cp2, _dl_progname);
 576
 577                         tpnt1 = _dl_load_shared_library(0, &rpnt, NULL, cp2, trace_loaded_objects);
 578                         if (!tpnt1) {
 579 #ifdef __LDSO_LDD_SUPPORT__
 580                                 if (trace_loaded_objects)
 581                                         _dl_dprintf(1, "\t%s => not found\n", cp2);
 582                                 else
 583 #endif
 584                                 {
 585                                         _dl_dprintf(_dl_debug_file, "%s: can't load library '%s'\n", _dl_progname, cp2);
 586                                         _dl_exit(15);
 587                                 }
 588                         } else {
 589                                 tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
 590
 591                                 _dl_debug_early("Loading: (%x) %s\n", tpnt1->loadaddr, tpnt1->libname);
 592
 593 #ifdef __LDSO_LDD_SUPPORT__
 594                                 if (trace_loaded_objects &&
 595                                     tpnt1->usage_count == 1) {
 596                                         _dl_dprintf(1, "\t%s => %s (%x)\n",
 597                                                     cp2, tpnt1->libname,
 598                                                     (unsigned)tpnt1->loadaddr);
 599                                 }
 600 #endif
 601                         }
 602
 603                         /* find start of next library */
 604                         *cp = c;
 605                         for ( /*nada */ ; *cp && *cp == ' '; cp++)
 606                                 /*nada */ ;
 607                 }
 608
 609                 _dl_munmap(preload, st.st_size + 1);
 610         } while (0);
 611 #endif /* __LDSO_PRELOAD_FILE_SUPPORT__ */
 612
 613         nlist = 0;
 614         for (tcurr = _dl_loaded_modules; tcurr; tcurr = tcurr->next) {
 615                 ElfW(Dyn) *this_dpnt;
 616
 617                 nlist++;
 618                 for (this_dpnt = (ElfW(Dyn) *) tcurr->dynamic_addr; this_dpnt->d_tag; this_dpnt++) {
 619                         if (this_dpnt->d_tag == DT_NEEDED) {
 620                                 char *name;
 621                                 struct init_fini_list *tmp;
 622
 623                                 lpntstr = (char*) (tcurr->dynamic_info[DT_STRTAB] + this_dpnt->d_un.d_val);
 624                                 name = _dl_get_last_path_component(lpntstr);
 625                                 if (_dl_strcmp(name, UCLIBC_LDSO) == 0)
 626                                         continue;
 627
 628                                 _dl_if_debug_dprint("\tfile='%s';  needed by '%s'\n", lpntstr, _dl_progname);
 629
 630                                 if (!(tpnt1 = _dl_load_shared_library(0, &rpnt, tcurr, lpntstr, trace_loaded_objects))) {
 631 #ifdef __LDSO_LDD_SUPPORT__
 632                                         if (trace_loaded_objects) {
 633                                                 _dl_dprintf(1, "\t%s => not found\n", lpntstr);
 634                                                 continue;
 635                                         } else
 636 #endif
 637                                         {
 638                                                 _dl_dprintf(_dl_debug_file, "%s: can't load library '%s'\n", _dl_progname, lpntstr);
 639                                                 _dl_exit(16);
 640                                         }
 641                                 }
 642
 643                                 tmp = alloca(sizeof(struct init_fini_list)); /* Allocates on stack, no need to free this memory */
 644                                 tmp->tpnt = tpnt1;
 645                                 tmp->next = tcurr->init_fini;
 646                                 tcurr->init_fini = tmp;
 647
 648                                 tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
 649
 650                                 _dl_debug_early("Loading: (%x) %s\n", tpnt1->loadaddr, tpnt1->libname);
 651
 652 #ifdef __LDSO_LDD_SUPPORT__
 653                                 if (trace_loaded_objects &&
 654                                     tpnt1->usage_count == 1) {
 655                                         _dl_dprintf(1, "\t%s => %s (%x)\n",
 656                                                     lpntstr, tpnt1->libname,
 657                                                     (unsigned)tpnt1->loadaddr);
 658                                 }
 659 #endif
 660                         }
 661                 }
 662         }
 663         _dl_unmap_cache();
 664
 665         --nlist; /* Exclude the application. */
 666         init_fini_list = _dl_malloc(nlist * sizeof(struct elf_resolve *));
 667         i = 0;
 668         for (tcurr = _dl_loaded_modules->next; tcurr; tcurr = tcurr->next) {
 669                 init_fini_list[i++] = tcurr;
 670         }
 671
 672         /* Sort the INIT/FINI list in dependency order. */
 673         for (tcurr = _dl_loaded_modules->next; tcurr; tcurr = tcurr->next) {
 674                 int j, k;
 675
 676                 for (j = 0; init_fini_list[j] != tcurr; ++j)
 677                         /* Empty */;
 678                 for (k = j + 1; k < nlist; ++k) {
 679                         struct init_fini_list *runp = init_fini_list[k]->init_fini;
 680
 681                         for (; runp; runp = runp->next) {
 682                                 if (runp->tpnt == tcurr) {
 683                                         struct elf_resolve *here = init_fini_list[k];
 684                                         _dl_if_debug_dprint("Move %s from pos %d to %d in INIT/FINI list\n", here->libname, k, j);
 685                                         for (i = (k - j); i; --i)
 686                                                 init_fini_list[i+j] = init_fini_list[i+j-1];
 687                                         init_fini_list[j] = here;
 688                                         ++j;
 689                                         break;
 690                                 }
 691                         }
 692                 }
 693         }
 694 #ifdef __SUPPORT_LD_DEBUG__
 695         if(_dl_debug) {
 696                 _dl_dprintf(_dl_debug_file, "\nINIT/FINI order and dependencies:\n");
 697                 for (i = 0; i < nlist; i++) {
 698                         struct init_fini_list *tmp;
 699
 700                         _dl_dprintf(_dl_debug_file, "lib: %s has deps:\n",
 701                                     init_fini_list[i]->libname);
 702                         tmp = init_fini_list[i]->init_fini;
 703                         for (; tmp; tmp = tmp->next)
 704                                 _dl_dprintf(_dl_debug_file, " %s ", tmp->tpnt->libname);
 705                         _dl_dprintf(_dl_debug_file, "\n");
 706                 }
 707         }
 708 #endif
 709
 710         /*
 711          * If the program interpreter is not in the module chain, add it.
 712          * This will be required for dlopen to be able to access the internal
 713          * functions in the dynamic linker and to relocate the interpreter
 714          * again once all libs are loaded.
 715          */
 716         if (tpnt) {
 717                 ElfW(Ehdr) *epnt = (ElfW(Ehdr) *) auxvt[AT_BASE].a_un.a_val;
 718                 ElfW(Phdr) *myppnt = (ElfW(Phdr) *) (load_addr + epnt->e_phoff);
 719                 int j;
 720
 721                 tpnt = _dl_add_elf_hash_table(tpnt->libname, (char *)load_addr,
 722                                               tpnt->dynamic_info,
 723                                               (unsigned long)tpnt->dynamic_addr,
 724                                               0);
 725
 726                 tpnt->n_phent = epnt->e_phnum;
 727                 tpnt->ppnt = myppnt;
 728                 for (j = 0; j < epnt->e_phnum; j++, myppnt++) {
 729                         if (myppnt->p_type ==  PT_GNU_RELRO) {
 730                                 tpnt->relro_addr = myppnt->p_vaddr;
 731                                 tpnt->relro_size = myppnt->p_memsz;
 732                                 break;
 733                         }
 734                 }
 735                 tpnt->libtype = program_interpreter;
 736                 tpnt->usage_count++;
 737                 tpnt->symbol_scope = _dl_symbol_tables;
 738                 if (rpnt) {
 739                         rpnt->next = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
 740                         _dl_memset(rpnt->next, 0, sizeof(struct dyn_elf));
 741                         rpnt->next->prev = rpnt;
 742                         rpnt = rpnt->next;
 743                 } else {
 744                         rpnt = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
 745                         _dl_memset(rpnt, 0, sizeof(struct dyn_elf));
 746                 }
 747                 rpnt->dyn = tpnt;
 748                 tpnt->rtld_flags = RTLD_NOW | RTLD_GLOBAL; /* Must not be LAZY */
 749 #ifdef RERELOCATE_LDSO
 750                 /* Only rerelocate functions for now. */
 751                 tpnt->init_flag = RELOCS_DONE;
 752                 lpnt = (unsigned long *) (tpnt->dynamic_info[DT_PLTGOT]);
 753 # ifdef ALLOW_ZERO_PLTGOT
 754                 if (tpnt->dynamic_info[DT_PLTGOT])
 755 # endif
 756                         INIT_GOT(lpnt, tpnt);
 757 #else
 758                 tpnt->init_flag = RELOCS_DONE | JMP_RELOCS_DONE;
 759 #endif
 760                 tpnt = NULL;
 761         }
 762
 763 #ifdef __LDSO_LDD_SUPPORT__
 764         /* End of the line for ldd.... */
 765         if (trace_loaded_objects) {
 766                 _dl_dprintf(1, "\t%s => %s (%x)\n",
 767                             rpnt->dyn->libname + _dl_strlen(_dl_ldsopath) + 1,
 768                             rpnt->dyn->libname, rpnt->dyn->loadaddr);
 769                 _dl_exit(0);
 770         }
 771 #endif
 772
 773         _dl_debug_early("Beginning relocation fixups\n");
 774
 775 #ifdef __mips__
 776         /*
 777          * Relocation of the GOT entries for MIPS have to be done
 778          * after all the libraries have been loaded.
 779          */
 780         _dl_perform_mips_global_got_relocations(_dl_loaded_modules, !unlazy);
 781 #endif
 782
 783         /*
 784          * OK, now all of the kids are tucked into bed in their proper
 785          * addresses.  Now we go through and look for REL and RELA records that
 786          * indicate fixups to the GOT tables.  We need to do this in reverse
 787          * order so that COPY directives work correctly.
 788          */
 789         if (_dl_symbol_tables)
 790                 if (_dl_fixup(_dl_symbol_tables, unlazy))
 791                         _dl_exit(-1);
 792
 793         for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
 794                 if (tpnt->relro_size)
 795                         _dl_protect_relro (tpnt);
 796         }
 797
 798         /* OK, at this point things are pretty much ready to run.  Now we need
 799          * to touch up a few items that are required, and then we can let the
 800          * user application have at it.  Note that the dynamic linker itself
 801          * is not guaranteed to be fully dynamicly linked if we are using
 802          * ld.so.1, so we have to look up each symbol individually.
 803          */
 804
 805         _dl_envp = (unsigned long *) (intptr_t) _dl_find_hash("__environ", _dl_symbol_tables, NULL, 0);
 806         if (_dl_envp)
 807                 *_dl_envp = (unsigned long) envp;
 808
 809 #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
 810         {
 811                 unsigned int j;
 812                 ElfW(Phdr) *myppnt;
 813
 814                 /* We had to set the protections of all pages to R/W for
 815                  * dynamic linking.  Set text pages back to R/O.
 816                  */
 817                 for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
 818                         for (myppnt = tpnt->ppnt, j = 0; j < tpnt->n_phent; j++, myppnt++) {
 819                                 if (myppnt->p_type == PT_LOAD && !(myppnt->p_flags & PF_W) && tpnt->dynamic_info[DT_TEXTREL]) {
 820                                         _dl_mprotect((void *) (tpnt->loadaddr + (myppnt->p_vaddr & PAGE_ALIGN)),
 821                                                         (myppnt->p_vaddr & ADDR_ALIGN) + (unsigned long) myppnt->p_filesz, LXFLAGS(myppnt->p_flags));
 822                                 }
 823                         }
 824                 }
 825
 826         }
 827 #endif
 828         /* Notify the debugger we have added some objects. */
 829         _dl_debug_addr->r_state = RT_ADD;
 830         _dl_debug_state();
 831
 832         /* Run pre-initialization functions for the executable.  */
 833         _dl_run_array_forward(_dl_loaded_modules->dynamic_info[DT_PREINIT_ARRAY],
 834                               _dl_loaded_modules->dynamic_info[DT_PREINIT_ARRAYSZ],
 835                               _dl_loaded_modules->loadaddr);
 836
 837         /* Run initialization functions for loaded objects.  For the
 838            main executable, they will be run from __uClibc_main.  */
 839         for (i = nlist; i; --i) {
 840                 tpnt = init_fini_list[i-1];
 841                 tpnt->init_fini = NULL; /* Clear, since alloca was used */
 842                 if (tpnt->init_flag & INIT_FUNCS_CALLED)
 843                         continue;
 844                 tpnt->init_flag |= INIT_FUNCS_CALLED;
 845
 846                 if (tpnt->dynamic_info[DT_INIT]) {
 847                         void (*dl_elf_func) (void);
 848
 849                         dl_elf_func = (void (*)(void)) (intptr_t) (tpnt->loadaddr + tpnt->dynamic_info[DT_INIT]);
 850
 851                         _dl_if_debug_dprint("calling INIT: %s\n\n", tpnt->libname);
 852
 853                         (*dl_elf_func) ();
 854                 }
 855
 856                 _dl_run_init_array(tpnt);
 857         }
 858
 859         /* Find the real malloc function and make ldso functions use that from now on */
 860          _dl_malloc_function = (void* (*)(size_t)) (intptr_t) _dl_find_hash("malloc",
 861                          _dl_symbol_tables, NULL, ELF_RTYPE_CLASS_PLT);
 862
 863         /* Notify the debugger that all objects are now mapped in.  */
 864         _dl_debug_addr->r_state = RT_CONSISTENT;
 865         _dl_debug_state();
 866 }
 867
 868 char *_dl_getenv(const char *symbol, char **envp)
 869 {
 870         char *pnt;
 871         const char *pnt1;
 872
 873         while ((pnt = *envp++)) {
 874                 pnt1 = symbol;
 875                 while (*pnt && *pnt == *pnt1)
 876                         pnt1++, pnt++;
 877                 if (!*pnt || *pnt != '=' || *pnt1)
 878                         continue;
 879                 return pnt + 1;
 880         }
 881         return 0;
 882 }
 883
 884 void _dl_unsetenv(const char *symbol, char **envp)
 885 {
 886         char *pnt;
 887         const char *pnt1;
 888         char **newenvp = envp;
 889
 890         for (pnt = *envp; pnt; pnt = *++envp) {
 891                 pnt1 = symbol;
 892                 while (*pnt && *pnt == *pnt1)
 893                         pnt1++, pnt++;
 894                 if (!*pnt || *pnt != '=' || *pnt1)
 895                         *newenvp++ = *envp;
 896         }
 897         *newenvp++ = *envp;
 898         return;
 899 }
 900
 901 static int _dl_suid_ok(void)
 902 {
 903         __kernel_uid_t uid, euid;
 904         __kernel_gid_t gid, egid;
 905
 906         uid = _dl_getuid();
 907         euid = _dl_geteuid();
 908         gid = _dl_getgid();
 909         egid = _dl_getegid();
 910
 911         if(uid == euid && gid == egid) {
 912                 return 1;
 913         }
 914         return 0;
 915 }
 916
 917 void *_dl_malloc(int size)
 918 {
 919         void *retval;
 920
 921 #if 0
 922         _dl_debug_early("request for %d bytes\n", size);
 923 #endif
 924
 925         if (_dl_malloc_function)
 926                 return (*_dl_malloc_function) (size);
 927
 928         if (_dl_malloc_addr - _dl_mmap_zero + (unsigned)size > _dl_pagesize) {
 929                 _dl_debug_early("mmapping more memory\n");
 930                 _dl_mmap_zero = _dl_malloc_addr = _dl_mmap((void *) 0, size,
 931                                 PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 932                 if (_dl_mmap_check_error(_dl_mmap_zero)) {
 933                         _dl_dprintf(_dl_debug_file, "%s: mmap of a spare page failed!\n", _dl_progname);
 934                         _dl_exit(20);
 935                 }
 936         }
 937         retval = _dl_malloc_addr;
 938         _dl_malloc_addr += size;
 939
 940         /*
 941          * Align memory to 4 byte boundary.  Some platforms require this,
 942          * others simply get better performance.
 943          */
 944         _dl_malloc_addr = (unsigned char *) (((unsigned long) _dl_malloc_addr + 3) & ~(3));
 945         return retval;
 946 }
 947
 948 #include "dl-hash.c"
 949 #include "dl-elf.c"