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