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 /* 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 rtld_hidden_proto(_dl_debug_state, noinline);
  79 void _dl_debug_state(void)
  80 {
  81         /* Make sure GCC doesn't recognize this function as pure, to avoid
  82          * having the calls optimized away.
  83          */
  84         __asm__("");
  85 }
  86
  87 static unsigned char *_dl_malloc_addr = 0;      /* Lets _dl_malloc use the already allocated memory page */
  88 static unsigned char *_dl_mmap_zero   = 0;      /* Also used by _dl_malloc */
  89
  90 static struct elf_resolve **init_fini_list;
  91 static unsigned int nlist; /* # items in init_fini_list */
  92 extern void _start(void);
  93
  94 #ifdef __UCLIBC_HAS_SSP__
  95 # include <dl-osinfo.h>
  96 uintptr_t stack_chk_guard;
  97 # ifndef THREAD_SET_STACK_GUARD
  98 /* Only exported for architectures that don't store the stack guard canary
  99  * in local thread area.  */
 100 uintptr_t __stack_chk_guard attribute_relro;
 101 #  ifdef __UCLIBC_HAS_SSP_COMPAT__
 102 strong_alias(__stack_chk_guard,__guard)
 103 #  endif
 104 # elif __UCLIBC_HAS_SSP_COMPAT__
 105 uintptr_t __guard attribute_relro;
 106 # endif
 107 #endif
 108
 109 static void _dl_run_array_forward(unsigned long array, unsigned long size,
 110                                   DL_LOADADDR_TYPE loadaddr)
 111 {
 112         if (array != 0) {
 113                 unsigned int j;
 114                 unsigned int jm;
 115                 ElfW(Addr) *addrs;
 116                 jm = size / sizeof (ElfW(Addr));
 117                 addrs = (ElfW(Addr) *) DL_RELOC_ADDR(loadaddr, array);
 118                 for (j = 0; j < jm; ++j) {
 119                         void (*dl_elf_func) (void);
 120                         dl_elf_func = (void (*)(void)) (intptr_t) addrs[j];
 121                         DL_CALL_FUNC_AT_ADDR (dl_elf_func, loadaddr, (void (*)(void)));
 122                 }
 123         }
 124 }
 125
 126 void _dl_run_init_array(struct elf_resolve *tpnt);
 127 void _dl_run_init_array(struct elf_resolve *tpnt)
 128 {
 129         _dl_run_array_forward(tpnt->dynamic_info[DT_INIT_ARRAY],
 130                               tpnt->dynamic_info[DT_INIT_ARRAYSZ],
 131                               tpnt->loadaddr);
 132 }
 133
 134 void _dl_app_init_array(void);
 135 void _dl_app_init_array(void)
 136 {
 137         _dl_run_init_array(_dl_loaded_modules);
 138 }
 139
 140 void _dl_run_fini_array(struct elf_resolve *tpnt);
 141 void _dl_run_fini_array(struct elf_resolve *tpnt)
 142 {
 143         if (tpnt->dynamic_info[DT_FINI_ARRAY]) {
 144                 ElfW(Addr) *array = (ElfW(Addr) *) DL_RELOC_ADDR(tpnt->loadaddr, tpnt->dynamic_info[DT_FINI_ARRAY]);
 145                 unsigned int i = (tpnt->dynamic_info[DT_FINI_ARRAYSZ] / sizeof(ElfW(Addr)));
 146                 while (i-- > 0) {
 147                         void (*dl_elf_func) (void);
 148                         dl_elf_func = (void (*)(void)) (intptr_t) array[i];
 149                         DL_CALL_FUNC_AT_ADDR (dl_elf_func, tpnt->loadaddr, (void (*)(void)));
 150                 }
 151         }
 152 }
 153
 154 void _dl_app_fini_array(void);
 155 void _dl_app_fini_array(void)
 156 {
 157         _dl_run_fini_array(_dl_loaded_modules);
 158 }
 159
 160 static void __attribute__ ((destructor)) __attribute_used__ _dl_fini(void)
 161 {
 162         int i;
 163         struct elf_resolve * tpnt;
 164
 165         for (i = 0; i < nlist; ++i) {
 166                 tpnt = init_fini_list[i];
 167                 if (tpnt->init_flag & FINI_FUNCS_CALLED)
 168                         continue;
 169                 tpnt->init_flag |= FINI_FUNCS_CALLED;
 170                 _dl_run_fini_array(tpnt);
 171                 if (tpnt->dynamic_info[DT_FINI]) {
 172                         void (*dl_elf_func) (void);
 173
 174                         dl_elf_func = (void (*)(void)) (intptr_t) DL_RELOC_ADDR(tpnt->loadaddr, tpnt->dynamic_info[DT_FINI]);
 175                         _dl_if_debug_dprint("\ncalling FINI: %s\n\n", tpnt->libname);
 176                         DL_CALL_FUNC_AT_ADDR (dl_elf_func, tpnt->loadaddr, (void(*)(void)));
 177                 }
 178         }
 179 }
 180
 181 void _dl_get_ready_to_run(struct elf_resolve *tpnt, DL_LOADADDR_TYPE load_addr,
 182                           ElfW(auxv_t) auxvt[AT_EGID + 1], char **envp,
 183                           char **argv)
 184 {
 185         ElfW(Phdr) *ppnt;
 186         ElfW(Dyn) *dpnt;
 187         char *lpntstr;
 188         unsigned int i;
 189         int unlazy = 0, trace_loaded_objects = 0;
 190         struct dyn_elf *rpnt;
 191         struct elf_resolve *tcurr;
 192         struct elf_resolve *tpnt1;
 193         struct elf_resolve app_tpnt_tmp;
 194         struct elf_resolve *app_tpnt = &app_tpnt_tmp;
 195         struct r_debug *debug_addr;
 196         unsigned long *lpnt;
 197         unsigned long *_dl_envp;                /* The environment address */
 198         ElfW(Addr) relro_addr = 0;
 199         size_t relro_size = 0;
 200         struct stat st;
 201
 202         /* Wahoo!!! We managed to make a function call!  Get malloc
 203          * setup so we can use _dl_dprintf() to print debug noise
 204          * instead of the SEND_STDERR macros used in dl-startup.c */
 205
 206         _dl_memset(app_tpnt, 0x00, sizeof(*app_tpnt));
 207
 208         /* Store the page size for later use */
 209         _dl_pagesize = (auxvt[AT_PAGESZ].a_un.a_val) ? (size_t) auxvt[AT_PAGESZ].a_un.a_val : PAGE_SIZE;
 210         /* Make it so _dl_malloc can use the page of memory we have already
 211          * allocated.  We shouldn't need to grab any more memory.  This must
 212          * be first since things like _dl_dprintf() use _dl_malloc()...
 213          */
 214         _dl_malloc_addr = (unsigned char *)_dl_pagesize;
 215         _dl_mmap_zero = 0;
 216
 217         /* Wahoo!!! */
 218         _dl_debug_early("Cool, ldso survived making function calls\n");
 219
 220         /* Now we have done the mandatory linking of some things.  We are now
 221          * free to start using global variables, since these things have all
 222          * been fixed up by now.  Still no function calls outside of this
 223          * library, since the dynamic resolver is not yet ready.
 224          */
 225         if (argv[0]) {
 226                 _dl_progname = argv[0];
 227         }
 228
 229         if (_start == (void *) auxvt[AT_ENTRY].a_un.a_val) {
 230                 _dl_dprintf(_dl_debug_file, "Standalone execution is not supported yet\n");
 231                 _dl_exit(1);
 232         }
 233
 234         /* Start to build the tables of the modules that are required for
 235          * this beast to run.  We start with the basic executable, and then
 236          * go from there.  Eventually we will run across ourself, and we
 237          * will need to properly deal with that as well.
 238          */
 239         rpnt = NULL;
 240         if (_dl_getenv("LD_BIND_NOW", envp))
 241                 unlazy = RTLD_NOW;
 242
 243         /* Now we need to figure out what kind of options are selected.
 244          * Note that for SUID programs we ignore the settings in
 245          * LD_LIBRARY_PATH.
 246          */
 247         if ((auxvt[AT_UID].a_un.a_val == (size_t)-1 && _dl_suid_ok()) ||
 248             (auxvt[AT_UID].a_un.a_val != (size_t)-1 &&
 249              auxvt[AT_UID].a_un.a_val == auxvt[AT_EUID].a_un.a_val &&
 250              auxvt[AT_GID].a_un.a_val == auxvt[AT_EGID].a_un.a_val)) {
 251                 _dl_secure = 0;
 252                 _dl_preload = _dl_getenv("LD_PRELOAD", envp);
 253                 _dl_library_path = _dl_getenv("LD_LIBRARY_PATH", envp);
 254         } else {
 255                 static const char unsecure_envvars[] =
 256 #ifdef EXTRA_UNSECURE_ENVVARS
 257                         EXTRA_UNSECURE_ENVVARS
 258 #endif
 259                         UNSECURE_ENVVARS;
 260                 const char *nextp;
 261                 _dl_secure = 1;
 262
 263                 nextp = unsecure_envvars;
 264                 do {
 265                         _dl_unsetenv (nextp, envp);
 266                         /* We could use rawmemchr but this need not be fast.  */
 267                         nextp = (char *) _dl_strchr(nextp, '\0') + 1;
 268                 } while (*nextp != '\0');
 269                 _dl_preload = NULL;
 270                 _dl_library_path = NULL;
 271                 /* SUID binaries can be exploited if they do LAZY relocation. */
 272                 unlazy = RTLD_NOW;
 273         }
 274
 275         /* sjhill: your TLS init should go before this */
 276 #ifdef __UCLIBC_HAS_SSP__
 277         /* Set up the stack checker's canary.  */
 278         stack_chk_guard = _dl_setup_stack_chk_guard ();
 279 # ifdef THREAD_SET_STACK_GUARD
 280         THREAD_SET_STACK_GUARD (stack_chk_guard);
 281 #  ifdef __UCLIBC_HAS_SSP_COMPAT__
 282         __guard = stack_chk_guard;
 283 #  endif
 284 # else
 285         __stack_chk_guard = stack_chk_guard;
 286 # endif
 287 #endif
 288
 289         /* At this point we are now free to examine the user application,
 290          * and figure out which libraries are supposed to be called.  Until
 291          * we have this list, we will not be completely ready for dynamic
 292          * linking.
 293          */
 294
 295         /* Find the runtime load address of the main executable.  This may be
 296          * different from what the ELF header says for ET_DYN/PIE executables.
 297          */
 298         {
 299                 unsigned int idx;
 300                 ElfW(Phdr) *phdr = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
 301
 302                 for (idx = 0; idx < auxvt[AT_PHNUM].a_un.a_val; idx++, phdr++)
 303                         if (phdr->p_type == PT_PHDR) {
 304                                 DL_INIT_LOADADDR_PROG(app_tpnt->loadaddr, auxvt[AT_PHDR].a_un.a_val - phdr->p_vaddr);
 305                                 break;
 306                         }
 307
 308                 if (DL_LOADADDR_BASE(app_tpnt->loadaddr))
 309                         _dl_debug_early("Position Independent Executable: "
 310                                         "app_tpnt->loadaddr=%x\n", DL_LOADADDR_BASE(app_tpnt->loadaddr));
 311         }
 312
 313         /*
 314          * This is used by gdb to locate the chain of shared libraries that are
 315          * currently loaded.
 316          */
 317         debug_addr = _dl_malloc(sizeof(struct r_debug));
 318         _dl_memset(debug_addr, 0, sizeof(struct r_debug));
 319
 320         ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
 321         for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++) {
 322                 if (ppnt->p_type == PT_GNU_RELRO) {
 323                         relro_addr = ppnt->p_vaddr;
 324                         relro_size = ppnt->p_memsz;
 325                 }
 326                 if (ppnt->p_type == PT_DYNAMIC) {
 327                         dpnt = (ElfW(Dyn) *) DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr);
 328                         _dl_parse_dynamic_info(dpnt, app_tpnt->dynamic_info, debug_addr, app_tpnt->loadaddr);
 329 #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
 330                         /* Ugly, ugly.  We need to call mprotect to change the
 331                          * protection of the text pages so that we can do the
 332                          * dynamic linking.  We can set the protection back
 333                          * again once we are done.
 334                          */
 335                         _dl_debug_early("calling mprotect on the application program\n");
 336                         /* Now cover the application program. */
 337                         if (app_tpnt->dynamic_info[DT_TEXTREL]) {
 338                                 ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
 339                                 for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++) {
 340                                         if (ppnt->p_type == PT_LOAD && !(ppnt->p_flags & PF_W))
 341                                                 _dl_mprotect((void *) (DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr) & PAGE_ALIGN),
 342                                                              ((ppnt->p_vaddr + app_tpnt->loadaddr) & ADDR_ALIGN) +
 343                                                              (unsigned long) ppnt->p_filesz,
 344                                                              PROT_READ | PROT_WRITE | PROT_EXEC);
 345                                 }
 346                         }
 347 #endif
 348
 349 #ifndef ALLOW_ZERO_PLTGOT
 350                         /* make sure it's really there. */
 351                         if (app_tpnt->dynamic_info[DT_PLTGOT] == 0)
 352                                 continue;
 353 #endif
 354                         /* OK, we have what we need - slip this one into the list. */
 355                         app_tpnt = _dl_add_elf_hash_table(_dl_progname, app_tpnt->loadaddr,
 356                                         app_tpnt->dynamic_info,
 357                                         DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr),
 358                                         ppnt->p_filesz);
 359                         _dl_loaded_modules->libtype = elf_executable;
 360                         _dl_loaded_modules->ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
 361                         _dl_loaded_modules->n_phent = auxvt[AT_PHNUM].a_un.a_val;
 362                         _dl_symbol_tables = rpnt = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
 363                         _dl_memset(rpnt, 0, sizeof(struct dyn_elf));
 364                         rpnt->dyn = _dl_loaded_modules;
 365                         app_tpnt->rtld_flags = unlazy | RTLD_GLOBAL;
 366                         app_tpnt->usage_count++;
 367                         app_tpnt->symbol_scope = _dl_symbol_tables;
 368                         lpnt = (unsigned long *) (app_tpnt->dynamic_info[DT_PLTGOT]);
 369 #ifdef ALLOW_ZERO_PLTGOT
 370                         if (lpnt)
 371 #endif
 372                                 INIT_GOT(lpnt, _dl_loaded_modules);
 373                 }
 374
 375                 /* OK, fill this in - we did not have this before */
 376                 if (ppnt->p_type == PT_INTERP) {
 377                         char *ptmp;
 378
 379                         tpnt->libname = (char *) DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr);
 380
 381                         /* Store the path where the shared lib loader was found
 382                          * for later use
 383                          */
 384                         _dl_ldsopath = _dl_strdup(tpnt->libname);
 385                         ptmp = _dl_strrchr(_dl_ldsopath, '/');
 386                         if (ptmp != _dl_ldsopath)
 387                                 *ptmp = '\0';
 388
 389                         _dl_debug_early("Lib Loader: (%x) %s\n", DL_LOADADDR_BASE(tpnt->loadaddr), tpnt->libname);
 390                 }
 391         }
 392         app_tpnt->relro_addr = relro_addr;
 393         app_tpnt->relro_size = relro_size;
 394
 395 #ifdef __SUPPORT_LD_DEBUG__
 396         _dl_debug = _dl_getenv("LD_DEBUG", envp);
 397         if (_dl_debug) {
 398                 if (_dl_strstr(_dl_debug, "all")) {
 399                         _dl_debug_detail = _dl_debug_move = _dl_debug_symbols
 400                                 = _dl_debug_reloc = _dl_debug_bindings = _dl_debug_nofixups = (void*)1;
 401                 } else {
 402                         _dl_debug_detail   = _dl_strstr(_dl_debug, "detail");
 403                         _dl_debug_move     = _dl_strstr(_dl_debug, "move");
 404                         _dl_debug_symbols  = _dl_strstr(_dl_debug, "sym");
 405                         _dl_debug_reloc    = _dl_strstr(_dl_debug, "reloc");
 406                         _dl_debug_nofixups = _dl_strstr(_dl_debug, "nofix");
 407                         _dl_debug_bindings = _dl_strstr(_dl_debug, "bind");
 408                 }
 409         }
 410
 411         {
 412                 const char *dl_debug_output;
 413
 414                 dl_debug_output = _dl_getenv("LD_DEBUG_OUTPUT", envp);
 415
 416                 if (dl_debug_output) {
 417                         char tmp[22], *tmp1, *filename;
 418                         int len1, len2;
 419
 420                         _dl_memset(tmp, 0, sizeof(tmp));
 421                         tmp1 = _dl_simple_ltoa( tmp, (unsigned long)_dl_getpid());
 422
 423                         len1 = _dl_strlen(dl_debug_output);
 424                         len2 = _dl_strlen(tmp1);
 425
 426                         filename = _dl_malloc(len1+len2+2);
 427
 428                         if (filename) {
 429                                 _dl_strcpy (filename, dl_debug_output);
 430                                 filename[len1] = '.';
 431                                 _dl_strcpy (&filename[len1+1], tmp1);
 432
 433                                 _dl_debug_file= _dl_open(filename, O_WRONLY|O_CREAT, 0644);
 434                                 if (_dl_debug_file < 0) {
 435                                         _dl_debug_file = 2;
 436                                         _dl_dprintf(_dl_debug_file, "can't open file: '%s'\n",filename);
 437                                 }
 438                         }
 439                 }
 440         }
 441 #endif
 442
 443         if (_dl_getenv("LD_TRACE_LOADED_OBJECTS", envp) != NULL) {
 444                 trace_loaded_objects++;
 445         }
 446
 447 #ifndef __LDSO_LDD_SUPPORT__
 448         if (trace_loaded_objects) {
 449                 _dl_dprintf(_dl_debug_file, "Use the ldd provided by uClibc\n");
 450                 _dl_exit(1);
 451         }
 452 #endif
 453
 454         /*
 455          * OK, fix one more thing - set up debug_addr so it will point
 456          * to our chain.  Later we may need to fill in more fields, but this
 457          * should be enough for now.
 458          */
 459         debug_addr->r_map = (struct link_map *) _dl_loaded_modules;
 460         debug_addr->r_version = 1;
 461         debug_addr->r_ldbase = DL_LOADADDR_BASE(load_addr);
 462         debug_addr->r_brk = (unsigned long) &_dl_debug_state;
 463         _dl_debug_addr = debug_addr;
 464
 465         /* Notify the debugger we are in a consistant state */
 466         _dl_debug_addr->r_state = RT_CONSISTENT;
 467         _dl_debug_state();
 468
 469         /* OK, we now have the application in the list, and we have some
 470          * basic stuff in place.  Now search through the list for other shared
 471          * libraries that should be loaded, and insert them on the list in the
 472          * correct order.
 473          */
 474
 475         _dl_map_cache();
 476
 477         if (_dl_preload) {
 478                 char c, *str, *str2;
 479
 480                 str = _dl_preload;
 481                 while (*str == ':' || *str == ' ' || *str == '\t')
 482                         str++;
 483
 484                 while (*str) {
 485                         str2 = str;
 486                         while (*str2 && *str2 != ':' && *str2 != ' ' && *str2 != '\t')
 487                                 str2++;
 488                         c = *str2;
 489                         *str2 = '\0';
 490
 491                         if (!_dl_secure || _dl_strchr(str, '/') == NULL) {
 492                                 _dl_if_debug_dprint("\tfile='%s';  needed by '%s'\n", str, _dl_progname);
 493
 494                                 tpnt1 = _dl_load_shared_library(_dl_secure, &rpnt, NULL, str, trace_loaded_objects);
 495                                 if (!tpnt1) {
 496 #ifdef __LDSO_LDD_SUPPORT__
 497                                         if (trace_loaded_objects)
 498                                                 _dl_dprintf(1, "\t%s => not found\n", str);
 499                                         else
 500 #endif
 501                                         {
 502                                                 _dl_dprintf(2, "%s: can't load " "library '%s'\n", _dl_progname, str);
 503                                                 _dl_exit(15);
 504                                         }
 505                                 } else {
 506                                         tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
 507
 508                                         _dl_debug_early("Loading: (%x) %s\n", DL_LOADADDR_BASE(tpnt1->loadaddr), tpnt1->libname);
 509
 510 #ifdef __LDSO_LDD_SUPPORT__
 511                                         if (trace_loaded_objects &&
 512                                             tpnt1->usage_count == 1) {
 513                                                 /* This is a real hack to make
 514                                                  * ldd not print the library
 515                                                  * itself when run on a
 516                                                  * library.
 517                                                  */
 518                                                 if (_dl_strcmp(_dl_progname, str) != 0)
 519                                                         _dl_dprintf(1, "\t%s => %s (%x)\n", str, tpnt1->libname,
 520                                                                     DL_LOADADDR_BASE(tpnt1->loadaddr));
 521                                         }
 522 #endif
 523                                 }
 524                         }
 525
 526                         *str2 = c;
 527                         str = str2;
 528                         while (*str == ':' || *str == ' ' || *str == '\t')
 529                                 str++;
 530                 }
 531         }
 532
 533 #ifdef __LDSO_PRELOAD_FILE_SUPPORT__
 534         do {
 535                 struct stat st;
 536                 char *preload;
 537                 int fd;
 538                 char c, *cp, *cp2;
 539
 540                 if (_dl_stat(LDSO_PRELOAD, &st) || st.st_size == 0) {
 541                         break;
 542                 }
 543
 544                 if ((fd = _dl_open(LDSO_PRELOAD, O_RDONLY, 0)) < 0) {
 545                         _dl_dprintf(2, "%s: can't open file '%s'\n",
 546                                     _dl_progname, LDSO_PRELOAD);
 547                         break;
 548                 }
 549
 550                 preload = (caddr_t) _dl_mmap(0, st.st_size + 1,
 551                                              PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
 552                 _dl_close(fd);
 553                 if (preload == (caddr_t) -1) {
 554                         _dl_dprintf(2, "%s:%i: can't map '%s'\n",
 555                                     _dl_progname, __LINE__, LDSO_PRELOAD);
 556                         break;
 557                 }
 558
 559                 /* convert all separators and comments to spaces */
 560                 for (cp = preload; *cp; /*nada */ ) {
 561                         if (*cp == ':' || *cp == '\t' || *cp == '\n') {
 562                                 *cp++ = ' ';
 563                         } else if (*cp == '#') {
 564                                 do {
 565                                         *cp++ = ' ';
 566                                 } while (*cp != '\n' && *cp != '\0');
 567                         } else {
 568                                 cp++;
 569                         }
 570                 }
 571
 572                 /* find start of first library */
 573                 for (cp = preload; *cp && *cp == ' '; cp++)
 574                         /*nada */ ;
 575
 576                 while (*cp) {
 577                         /* find end of library */
 578                         for (cp2 = cp; *cp && *cp != ' '; cp++)
 579                                 /*nada */ ;
 580                         c = *cp;
 581                         *cp = '\0';
 582
 583                         _dl_if_debug_dprint("\tfile='%s';  needed by '%s'\n", cp2, _dl_progname);
 584
 585                         tpnt1 = _dl_load_shared_library(0, &rpnt, NULL, cp2, trace_loaded_objects);
 586                         if (!tpnt1) {
 587 #ifdef __LDSO_LDD_SUPPORT__
 588                                 if (trace_loaded_objects)
 589                                         _dl_dprintf(1, "\t%s => not found\n", cp2);
 590                                 else
 591 #endif
 592                                 {
 593                                         _dl_dprintf(2, "%s: can't load library '%s'\n", _dl_progname, cp2);
 594                                         _dl_exit(15);
 595                                 }
 596                         } else {
 597                                 tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
 598
 599                                 _dl_debug_early("Loading: (%x) %s\n", DL_LOADADDR_BASE(tpnt1->loadaddr), tpnt1->libname);
 600
 601 #ifdef __LDSO_LDD_SUPPORT__
 602                                 if (trace_loaded_objects &&
 603                                     tpnt1->usage_count == 1) {
 604                                         _dl_dprintf(1, "\t%s => %s (%x)\n",
 605                                                     cp2, tpnt1->libname,
 606                                                     DL_LOADADDR_BASE(tpnt1->loadaddr));
 607                                 }
 608 #endif
 609                         }
 610
 611                         /* find start of next library */
 612                         *cp = c;
 613                         for ( /*nada */ ; *cp && *cp == ' '; cp++)
 614                                 /*nada */ ;
 615                 }
 616
 617                 _dl_munmap(preload, st.st_size + 1);
 618         } while (0);
 619 #endif /* __LDSO_PRELOAD_FILE_SUPPORT__ */
 620
 621         nlist = 0;
 622         for (tcurr = _dl_loaded_modules; tcurr; tcurr = tcurr->next) {
 623                 ElfW(Dyn) *this_dpnt;
 624
 625                 nlist++;
 626                 for (this_dpnt = (ElfW(Dyn) *) tcurr->dynamic_addr; this_dpnt->d_tag; this_dpnt++) {
 627                         if (this_dpnt->d_tag == DT_NEEDED) {
 628                                 char *name;
 629                                 struct init_fini_list *tmp;
 630
 631                                 lpntstr = (char*) (tcurr->dynamic_info[DT_STRTAB] + this_dpnt->d_un.d_val);
 632                                 name = _dl_get_last_path_component(lpntstr);
 633                                 if (_dl_strcmp(name, UCLIBC_LDSO) == 0)
 634                                         continue;
 635
 636                                 _dl_if_debug_dprint("\tfile='%s';  needed by '%s'\n", lpntstr, _dl_progname);
 637
 638                                 if (!(tpnt1 = _dl_load_shared_library(0, &rpnt, tcurr, lpntstr, trace_loaded_objects))) {
 639 #ifdef __LDSO_LDD_SUPPORT__
 640                                         if (trace_loaded_objects) {
 641                                                 _dl_dprintf(1, "\t%s => not found\n", lpntstr);
 642                                                 continue;
 643                                         } else
 644 #endif
 645                                         {
 646                                                 _dl_dprintf(2, "%s: can't load library '%s'\n", _dl_progname, lpntstr);
 647                                                 _dl_exit(16);
 648                                         }
 649                                 }
 650
 651                                 tmp = alloca(sizeof(struct init_fini_list)); /* Allocates on stack, no need to free this memory */
 652                                 tmp->tpnt = tpnt1;
 653                                 tmp->next = tcurr->init_fini;
 654                                 tcurr->init_fini = tmp;
 655
 656                                 tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
 657
 658                                 _dl_debug_early("Loading: (%x) %s\n", DL_LOADADDR_BASE(tpnt1->loadaddr), tpnt1->libname);
 659
 660 #ifdef __LDSO_LDD_SUPPORT__
 661                                 if (trace_loaded_objects &&
 662                                     tpnt1->usage_count == 1) {
 663                                         _dl_dprintf(1, "\t%s => %s (%x)\n",
 664                                                     lpntstr, tpnt1->libname,
 665                                                     DL_LOADADDR_BASE(tpnt1->loadaddr));
 666                                 }
 667 #endif
 668                         }
 669                 }
 670         }
 671         _dl_unmap_cache();
 672
 673         --nlist; /* Exclude the application. */
 674         init_fini_list = _dl_malloc(nlist * sizeof(struct elf_resolve *));
 675         i = 0;
 676         for (tcurr = _dl_loaded_modules->next; tcurr; tcurr = tcurr->next) {
 677                 init_fini_list[i++] = tcurr;
 678         }
 679
 680         /* Sort the INIT/FINI list in dependency order. */
 681         for (tcurr = _dl_loaded_modules->next; tcurr; tcurr = tcurr->next) {
 682                 int j, k;
 683
 684                 for (j = 0; init_fini_list[j] != tcurr; ++j)
 685                         /* Empty */;
 686                 for (k = j + 1; k < nlist; ++k) {
 687                         struct init_fini_list *runp = init_fini_list[k]->init_fini;
 688
 689                         for (; runp; runp = runp->next) {
 690                                 if (runp->tpnt == tcurr) {
 691                                         struct elf_resolve *here = init_fini_list[k];
 692                                         _dl_if_debug_dprint("Move %s from pos %d to %d in INIT/FINI list\n", here->libname, k, j);
 693                                         for (i = (k - j); i; --i)
 694                                                 init_fini_list[i+j] = init_fini_list[i+j-1];
 695                                         init_fini_list[j] = here;
 696                                         ++j;
 697                                         break;
 698                                 }
 699                         }
 700                 }
 701         }
 702 #ifdef __SUPPORT_LD_DEBUG__
 703         if (_dl_debug) {
 704                 _dl_dprintf(_dl_debug_file, "\nINIT/FINI order and dependencies:\n");
 705                 for (i = 0; i < nlist; i++) {
 706                         struct init_fini_list *tmp;
 707
 708                         _dl_dprintf(_dl_debug_file, "lib: %s has deps:\n",
 709                                     init_fini_list[i]->libname);
 710                         tmp = init_fini_list[i]->init_fini;
 711                         for (; tmp; tmp = tmp->next)
 712                                 _dl_dprintf(_dl_debug_file, " %s ", tmp->tpnt->libname);
 713                         _dl_dprintf(_dl_debug_file, "\n");
 714                 }
 715         }
 716 #endif
 717
 718         /*
 719          * If the program interpreter is not in the module chain, add it.
 720          * This will be required for dlopen to be able to access the internal
 721          * functions in the dynamic linker and to relocate the interpreter
 722          * again once all libs are loaded.
 723          */
 724         if (tpnt) {
 725                 ElfW(Ehdr) *epnt = (ElfW(Ehdr) *) auxvt[AT_BASE].a_un.a_val;
 726                 ElfW(Phdr) *myppnt = (ElfW(Phdr) *) DL_RELOC_ADDR(load_addr, epnt->e_phoff);
 727                 int j;
 728
 729                 tpnt = _dl_add_elf_hash_table(tpnt->libname, load_addr,
 730                                               tpnt->dynamic_info,
 731                                               (unsigned long)tpnt->dynamic_addr,
 732                                               0);
 733
 734                 if (_dl_stat(tpnt->libname, &st) >= 0) {
 735                         tpnt->st_dev = st.st_dev;
 736                         tpnt->st_ino = st.st_ino;
 737                 }
 738                 tpnt->n_phent = epnt->e_phnum;
 739                 tpnt->ppnt = myppnt;
 740                 for (j = 0; j < epnt->e_phnum; j++, myppnt++) {
 741                         if (myppnt->p_type ==  PT_GNU_RELRO) {
 742                                 tpnt->relro_addr = myppnt->p_vaddr;
 743                                 tpnt->relro_size = myppnt->p_memsz;
 744                                 break;
 745                         }
 746                 }
 747                 tpnt->libtype = program_interpreter;
 748                 tpnt->usage_count++;
 749                 tpnt->symbol_scope = _dl_symbol_tables;
 750                 if (rpnt) {
 751                         rpnt->next = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
 752                         _dl_memset(rpnt->next, 0, sizeof(struct dyn_elf));
 753                         rpnt->next->prev = rpnt;
 754                         rpnt = rpnt->next;
 755                 } else {
 756                         rpnt = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
 757                         _dl_memset(rpnt, 0, sizeof(struct dyn_elf));
 758                 }
 759                 rpnt->dyn = tpnt;
 760                 tpnt->rtld_flags = RTLD_NOW | RTLD_GLOBAL; /* Must not be LAZY */
 761 #ifdef RERELOCATE_LDSO
 762                 /* Only rerelocate functions for now. */
 763                 tpnt->init_flag = RELOCS_DONE;
 764                 lpnt = (unsigned long *) (tpnt->dynamic_info[DT_PLTGOT]);
 765 # ifdef ALLOW_ZERO_PLTGOT
 766                 if (tpnt->dynamic_info[DT_PLTGOT])
 767 # endif
 768                         INIT_GOT(lpnt, tpnt);
 769 #else
 770                 tpnt->init_flag = RELOCS_DONE | JMP_RELOCS_DONE;
 771 #endif
 772                 tpnt = NULL;
 773         }
 774
 775 #ifdef __LDSO_LDD_SUPPORT__
 776         /* End of the line for ldd.... */
 777         if (trace_loaded_objects) {
 778                 _dl_dprintf(1, "\t%s => %s (%x)\n",
 779                             rpnt->dyn->libname + _dl_strlen(_dl_ldsopath) + 1,
 780                             rpnt->dyn->libname, DL_LOADADDR_BASE(rpnt->dyn->loadaddr));
 781                 _dl_exit(0);
 782         }
 783 #endif
 784
 785         _dl_debug_early("Beginning relocation fixups\n");
 786
 787 #ifdef __mips__
 788         /*
 789          * Relocation of the GOT entries for MIPS have to be done
 790          * after all the libraries have been loaded.
 791          */
 792         _dl_perform_mips_global_got_relocations(_dl_loaded_modules, !unlazy);
 793 #endif
 794
 795         /*
 796          * OK, now all of the kids are tucked into bed in their proper
 797          * addresses.  Now we go through and look for REL and RELA records that
 798          * indicate fixups to the GOT tables.  We need to do this in reverse
 799          * order so that COPY directives work correctly.
 800          */
 801         if (_dl_symbol_tables)
 802                 if (_dl_fixup(_dl_symbol_tables, unlazy))
 803                         _dl_exit(-1);
 804
 805         for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
 806                 if (tpnt->relro_size)
 807                         _dl_protect_relro (tpnt);
 808         }
 809
 810         /* OK, at this point things are pretty much ready to run.  Now we need
 811          * to touch up a few items that are required, and then we can let the
 812          * user application have at it.  Note that the dynamic linker itself
 813          * is not guaranteed to be fully dynamicly linked if we are using
 814          * ld.so.1, so we have to look up each symbol individually.
 815          */
 816
 817         _dl_envp = (unsigned long *) (intptr_t) _dl_find_hash("__environ", _dl_symbol_tables, NULL, 0);
 818         if (_dl_envp)
 819                 *_dl_envp = (unsigned long) envp;
 820
 821 #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
 822         {
 823                 unsigned int j;
 824                 ElfW(Phdr) *myppnt;
 825
 826                 /* We had to set the protections of all pages to R/W for
 827                  * dynamic linking.  Set text pages back to R/O.
 828                  */
 829                 for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
 830                         for (myppnt = tpnt->ppnt, j = 0; j < tpnt->n_phent; j++, myppnt++) {
 831                                 if (myppnt->p_type == PT_LOAD && !(myppnt->p_flags & PF_W) && tpnt->dynamic_info[DT_TEXTREL]) {
 832                                         _dl_mprotect((void *) (DL_RELOC_ADDR(tpnt->loadaddr, myppnt->p_vaddr) & PAGE_ALIGN),
 833                                                         (myppnt->p_vaddr & ADDR_ALIGN) + (unsigned long) myppnt->p_filesz, LXFLAGS(myppnt->p_flags));
 834                                 }
 835                         }
 836                 }
 837
 838         }
 839 #endif
 840         /* Notify the debugger we have added some objects. */
 841         _dl_debug_addr->r_state = RT_ADD;
 842         _dl_debug_state();
 843
 844         /* Run pre-initialization functions for the executable.  */
 845         _dl_run_array_forward(_dl_loaded_modules->dynamic_info[DT_PREINIT_ARRAY],
 846                               _dl_loaded_modules->dynamic_info[DT_PREINIT_ARRAYSZ],
 847                               _dl_loaded_modules->loadaddr);
 848
 849         /* Run initialization functions for loaded objects.  For the
 850            main executable, they will be run from __uClibc_main.  */
 851         for (i = nlist; i; --i) {
 852                 tpnt = init_fini_list[i-1];
 853                 tpnt->init_fini = NULL; /* Clear, since alloca was used */
 854                 if (tpnt->init_flag & INIT_FUNCS_CALLED)
 855                         continue;
 856                 tpnt->init_flag |= INIT_FUNCS_CALLED;
 857
 858                 if (tpnt->dynamic_info[DT_INIT]) {
 859                         void (*dl_elf_func) (void);
 860
 861                         dl_elf_func = (void (*)(void)) DL_RELOC_ADDR(tpnt->loadaddr, tpnt->dynamic_info[DT_INIT]);
 862
 863                         _dl_if_debug_dprint("calling INIT: %s\n\n", tpnt->libname);
 864
 865                         DL_CALL_FUNC_AT_ADDR (dl_elf_func, tpnt->loadaddr, (void(*)(void)));
 866                 }
 867
 868                 _dl_run_init_array(tpnt);
 869         }
 870
 871         /* Find the real malloc function and make ldso functions use that from now on */
 872          _dl_malloc_function = (void* (*)(size_t)) (intptr_t) _dl_find_hash("malloc",
 873                          _dl_symbol_tables, NULL, ELF_RTYPE_CLASS_PLT);
 874
 875         /* Notify the debugger that all objects are now mapped in.  */
 876         _dl_debug_addr->r_state = RT_CONSISTENT;
 877         _dl_debug_state();
 878 }
 879
 880 char *_dl_getenv(const char *symbol, char **envp)
 881 {
 882         char *pnt;
 883         const char *pnt1;
 884
 885         while ((pnt = *envp++)) {
 886                 pnt1 = symbol;
 887                 while (*pnt && *pnt == *pnt1)
 888                         pnt1++, pnt++;
 889                 if (!*pnt || *pnt != '=' || *pnt1)
 890                         continue;
 891                 return pnt + 1;
 892         }
 893         return 0;
 894 }
 895
 896 void _dl_unsetenv(const char *symbol, char **envp)
 897 {
 898         char *pnt;
 899         const char *pnt1;
 900         char **newenvp = envp;
 901
 902         for (pnt = *envp; pnt; pnt = *++envp) {
 903                 pnt1 = symbol;
 904                 while (*pnt && *pnt == *pnt1)
 905                         pnt1++, pnt++;
 906                 if (!*pnt || *pnt != '=' || *pnt1)
 907                         *newenvp++ = *envp;
 908         }
 909         *newenvp++ = *envp;
 910         return;
 911 }
 912
 913 static int _dl_suid_ok(void)
 914 {
 915         __kernel_uid_t uid, euid;
 916         __kernel_gid_t gid, egid;
 917
 918         uid = _dl_getuid();
 919         euid = _dl_geteuid();
 920         gid = _dl_getgid();
 921         egid = _dl_getegid();
 922
 923         if (uid == euid && gid == egid) {
 924                 return 1;
 925         }
 926         return 0;
 927 }
 928
 929 void *_dl_malloc(int size)
 930 {
 931         void *retval;
 932
 933 #if 0
 934         _dl_debug_early("request for %d bytes\n", size);
 935 #endif
 936
 937         if (_dl_malloc_function)
 938                 return (*_dl_malloc_function) (size);
 939
 940         if (_dl_malloc_addr - _dl_mmap_zero + (unsigned)size > _dl_pagesize) {
 941                 _dl_debug_early("mmapping more memory\n");
 942                 _dl_mmap_zero = _dl_malloc_addr = _dl_mmap((void *) 0, size,
 943                                 PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 944                 if (_dl_mmap_check_error(_dl_mmap_zero)) {
 945                         _dl_dprintf(2, "%s: mmap of a spare page failed!\n", _dl_progname);
 946                         _dl_exit(20);
 947                 }
 948         }
 949         retval = _dl_malloc_addr;
 950         _dl_malloc_addr += size;
 951
 952         /*
 953          * Align memory to DL_MALLOC_ALIGN byte boundary.  Some
 954          * platforms require this, others simply get better
 955          * performance.
 956          */
 957         _dl_malloc_addr = (unsigned char *) (((unsigned long) _dl_malloc_addr + DL_MALLOC_ALIGN - 1) & ~(DL_MALLOC_ALIGN - 1));
 958         return retval;
 959 }
 960
 961 #include "dl-hash.c"
 962 #include "dl-elf.c"