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