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