ldso/ldso/ldso.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Program to load an ELF binary on a linux system, and run it
   4  * after resolving ELF shared library symbols
   5  *
   6  * Copyright (C) 2005 by Joakim Tjernlund
   7  * Copyright (C) 2000-2004 by Erik Andersen <andersen@codepoet.org>
   8  * Copyright (c) 1994-2000 Eric Youngdale, Peter MacDonald,
   9  *                              David Engel, Hongjiu Lu and Mitch D'Souza
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions and the following disclaimer.
  16  * 2. The name of the above contributors may not be
  17  *    used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33 #include "ldso.h"
  34 #include "unsecvars.h"
  35
  36 /* Pull in common debug code */
  37 #include "dl-debug.c"
  38
  39 #define ALLOW_ZERO_PLTGOT
  40
  41 /* Pull in the value of _dl_progname */
  42 #include "dl-progname.h"
  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 {
  79 }
  80
  81 static unsigned char *_dl_malloc_addr = 0;      /* Lets _dl_malloc use the already allocated memory page */
  82 static unsigned char *_dl_mmap_zero   = 0;      /* Also used by _dl_malloc */
  83
  84 static struct elf_resolve **init_fini_list;
  85 static int nlist; /* # items in init_fini_list */
  86 extern void _start(void);
  87
  88 #ifdef __UCLIBC_HAS_SSP__
  89 #include <dl-osinfo.h>
  90 #ifndef THREAD_SET_STACK_GUARD
  91 /* Only exported for architectures that don't store the stack guard canary
  92  * in local thread area.  */
  93 uintptr_t __stack_chk_guard attribute_relro;
  94 strong_alias(__stack_chk_guard,__guard)
  95 #endif
  96 #endif
  97
  98 static void __attribute__ ((destructor)) __attribute_used__ _dl_fini(void)
  99 {
 100         int i;
 101         struct elf_resolve * tpnt;
 102
 103         for (i = 0; i < nlist; ++i) {
 104                 tpnt = init_fini_list[i];
 105                 if (tpnt->init_flag & FINI_FUNCS_CALLED)
 106                         continue;
 107                 tpnt->init_flag |= FINI_FUNCS_CALLED;
 108                 if (tpnt->dynamic_info[DT_FINI]) {
 109                         void (*dl_elf_func) (void);
 110
 111                         dl_elf_func = (void (*)(void)) (intptr_t) (tpnt->loadaddr + tpnt->dynamic_info[DT_FINI]);
 112                         _dl_if_debug_dprint("\ncalling FINI: %s\n\n", tpnt->libname);
 113                         (*dl_elf_func) ();
 114                 }
 115         }
 116 }
 117
 118 void _dl_get_ready_to_run(struct elf_resolve *tpnt, unsigned long load_addr,
 119                           ElfW(auxv_t) auxvt[AT_EGID + 1], char **envp,
 120                           char **argv)
 121 {
 122         ElfW(Phdr) *ppnt;
 123         ElfW(Dyn) *dpnt;
 124         char *lpntstr;
 125         int i, unlazy = 0, trace_loaded_objects = 0;
 126         struct dyn_elf *rpnt;
 127         struct elf_resolve *tcurr;
 128         struct elf_resolve *tpnt1;
 129         struct elf_resolve app_tpnt_tmp;
 130         struct elf_resolve *app_tpnt = &app_tpnt_tmp;
 131         struct r_debug *debug_addr;
 132         unsigned long *lpnt;
 133         unsigned long *_dl_envp;                /* The environment address */
 134         ElfW(Addr) relro_addr = 0;
 135         size_t relro_size = 0;
 136
 137         /* Wahoo!!! We managed to make a function call!  Get malloc
 138          * setup so we can use _dl_dprintf() to print debug noise
 139          * instead of the SEND_STDERR macros used in dl-startup.c */
 140
 141
 142         /* Store the page size for later use */
 143         _dl_pagesize = (auxvt[AT_PAGESZ].a_un.a_val) ? (size_t) auxvt[AT_PAGESZ].a_un.a_val : PAGE_SIZE;
 144         /* Make it so _dl_malloc can use the page of memory we have already
 145          * allocated.  We shouldn't need to grab any more memory.  This must
 146          * be first since things like _dl_dprintf() use _dl_malloc()...
 147          */
 148         _dl_malloc_addr = (unsigned char *)_dl_pagesize;
 149         _dl_mmap_zero = 0;
 150
 151         /* Wahoo!!! */
 152         _dl_debug_early("Cool, ldso survived making function calls\n");
 153
 154         /* Now we have done the mandatory linking of some things.  We are now
 155          * free to start using global variables, since these things have all
 156          * been fixed up by now.  Still no function calls outside of this
 157          * library, since the dynamic resolver is not yet ready.
 158          */
 159         if (argv[0]) {
 160                 _dl_progname = argv[0];
 161         }
 162
 163         if (_start == (void *) auxvt[AT_ENTRY].a_un.a_val) {
 164                 _dl_dprintf(_dl_debug_file, "Standalone execution is not supported yet\n");
 165                 _dl_exit(1);
 166         }
 167
 168         /* Start to build the tables of the modules that are required for
 169          * this beast to run.  We start with the basic executable, and then
 170          * go from there.  Eventually we will run across ourself, and we
 171          * will need to properly deal with that as well.
 172          */
 173         rpnt = NULL;
 174         if (_dl_getenv("LD_BIND_NOW", envp))
 175                 unlazy = RTLD_NOW;
 176
 177         /* Now we need to figure out what kind of options are selected.
 178          * Note that for SUID programs we ignore the settings in
 179          * LD_LIBRARY_PATH.
 180          */
 181         if ((auxvt[AT_UID].a_un.a_val == -1 && _dl_suid_ok()) ||
 182             (auxvt[AT_UID].a_un.a_val != -1 &&
 183              auxvt[AT_UID].a_un.a_val == auxvt[AT_EUID].a_un.a_val &&
 184              auxvt[AT_GID].a_un.a_val == auxvt[AT_EGID].a_un.a_val)) {
 185                 _dl_secure = 0;
 186                 _dl_preload = _dl_getenv("LD_PRELOAD", envp);
 187                 _dl_library_path = _dl_getenv("LD_LIBRARY_PATH", envp);
 188         } else {
 189                 static const char unsecure_envvars[] =
 190 #ifdef EXTRA_UNSECURE_ENVVARS
 191                         EXTRA_UNSECURE_ENVVARS
 192 #endif
 193                         UNSECURE_ENVVARS;
 194                 const char *nextp;
 195                 _dl_secure = 1;
 196
 197                 nextp = unsecure_envvars;
 198                 do {
 199                         _dl_unsetenv (nextp, envp);
 200                         /* We could use rawmemchr but this need not be fast.  */
 201                         nextp = (char *) _dl_strchr(nextp, '\0') + 1;
 202                 } while (*nextp != '\0');
 203                 _dl_preload = NULL;
 204                 _dl_library_path = NULL;
 205                 /* SUID binaries can be exploited if they do LAZY relocation. */
 206                 unlazy = RTLD_NOW;
 207         }
 208
 209         /* sjhill: your TLS init should go before this */
 210 #ifdef __UCLIBC_HAS_SSP__
 211         /* Set up the stack checker's canary.  */
 212         uintptr_t stack_chk_guard = _dl_setup_stack_chk_guard ();
 213 # ifdef THREAD_SET_STACK_GUARD
 214         THREAD_SET_STACK_GUARD (stack_chk_guard);
 215 # else
 216         __stack_chk_guard = stack_chk_guard;
 217 # endif
 218 #endif
 219
 220         /* At this point we are now free to examine the user application,
 221          * and figure out which libraries are supposed to be called.  Until
 222          * we have this list, we will not be completely ready for dynamic
 223          * linking.
 224          */
 225
 226         /* Find the runtime load address of the main executable.  This may be
 227          * different from what the ELF header says for ET_DYN/PIE executables.
 228          */
 229         {
 230                 int i;
 231                 ElfW(Phdr) *ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
 232
 233                 for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++)
 234                         if (ppnt->p_type == PT_PHDR) {
 235                                 app_tpnt->loadaddr = (ElfW(Addr)) (auxvt[AT_PHDR].a_un.a_val - ppnt->p_vaddr);
 236                                 break;
 237                         }
 238
 239                 if (app_tpnt->loadaddr)
 240                         _dl_debug_early("Position Independent Executable: "
 241                                         "app_tpnt->loadaddr=%x\n", app_tpnt->loadaddr);
 242         }
 243
 244         /*
 245          * This is used by gdb to locate the chain of shared libraries that are
 246          * currently loaded.
 247          */
 248         debug_addr = _dl_malloc(sizeof(struct r_debug));
 249         _dl_memset(debug_addr, 0, sizeof(struct r_debug));
 250
 251         ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
 252         for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++) {
 253                 if (ppnt->p_type == PT_GNU_RELRO) {
 254                         relro_addr = ppnt->p_vaddr;
 255                         relro_size = ppnt->p_memsz;
 256                 }
 257                 if (ppnt->p_type == PT_DYNAMIC) {
 258                         dpnt = (ElfW(Dyn) *) (ppnt->p_vaddr + app_tpnt->loadaddr);
 259                         _dl_parse_dynamic_info(dpnt, app_tpnt->dynamic_info, debug_addr, app_tpnt->loadaddr);
 260 #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
 261                         /* Ugly, ugly.  We need to call mprotect to change the
 262                          * protection of the text pages so that we can do the
 263                          * dynamic linking.  We can set the protection back
 264                          * again once we are done.
 265                          */
 266                         _dl_debug_early("calling mprotect on the application program\n");
 267                         /* Now cover the application program. */
 268                         if (app_tpnt->dynamic_info[DT_TEXTREL]) {
 269                                 ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
 270                                 for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++) {
 271                                         if (ppnt->p_type == PT_LOAD && !(ppnt->p_flags & PF_W))
 272                                                 _dl_mprotect((void *) ((ppnt->p_vaddr + app_tpnt->loadaddr) & PAGE_ALIGN),
 273                                                              ((ppnt->p_vaddr + app_tpnt->loadaddr) & ADDR_ALIGN) +
 274                                                              (unsigned long) ppnt->p_filesz,
 275                                                              PROT_READ | PROT_WRITE | PROT_EXEC);
 276                                 }
 277                         }
 278 #endif
 279
 280 #ifndef ALLOW_ZERO_PLTGOT
 281                         /* make sure it's really there. */
 282                         if (app_tpnt->dynamic_info[DT_PLTGOT] == 0)
 283                                 continue;
 284 #endif
 285                         /* OK, we have what we need - slip this one into the list. */
 286                         app_tpnt = _dl_add_elf_hash_table(_dl_progname, (char *)app_tpnt->loadaddr,
 287                                         app_tpnt->dynamic_info, ppnt->p_vaddr + app_tpnt->loadaddr, ppnt->p_filesz);
 288                         _dl_loaded_modules->libtype = elf_executable;
 289                         _dl_loaded_modules->ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
 290                         _dl_loaded_modules->n_phent = auxvt[AT_PHNUM].a_un.a_val;
 291                         _dl_symbol_tables = rpnt = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
 292                         _dl_memset(rpnt, 0, sizeof(struct dyn_elf));
 293                         rpnt->dyn = _dl_loaded_modules;
 294                         app_tpnt->rtld_flags = unlazy | RTLD_GLOBAL;
 295                         app_tpnt->usage_count++;
 296                         app_tpnt->symbol_scope = _dl_symbol_tables;
 297                         lpnt = (unsigned long *) (app_tpnt->dynamic_info[DT_PLTGOT]);
 298 #ifdef ALLOW_ZERO_PLTGOT
 299                         if (lpnt)
 300 #endif
 301                                 INIT_GOT(lpnt, _dl_loaded_modules);
 302                 }
 303
 304                 /* OK, fill this in - we did not have this before */
 305                 if (ppnt->p_type == PT_INTERP) {
 306                         char *ptmp;
 307
 308                         tpnt->libname = (char *) ppnt->p_vaddr + app_tpnt->loadaddr;
 309
 310                         /* Store the path where the shared lib loader was found
 311                          * for later use
 312                          */
 313                         _dl_ldsopath = _dl_strdup(tpnt->libname);
 314                         ptmp = _dl_strrchr(_dl_ldsopath, '/');
 315                         if (ptmp != _dl_ldsopath)
 316                                 *ptmp = '\0';
 317
 318                         _dl_debug_early("Lib Loader: (%x) %s\n", tpnt->loadaddr, tpnt->libname);
 319                 }
 320         }
 321         app_tpnt->relro_addr = relro_addr;
 322         app_tpnt->relro_size = relro_size;
 323
 324 #ifdef __SUPPORT_LD_DEBUG__
 325         _dl_debug = _dl_getenv("LD_DEBUG", envp);
 326         if (_dl_debug) {
 327                 if (_dl_strstr(_dl_debug, "all")) {
 328                         _dl_debug_detail = _dl_debug_move = _dl_debug_symbols
 329                                 = _dl_debug_reloc = _dl_debug_bindings = _dl_debug_nofixups = (void*)1;
 330                 } else {
 331                         _dl_debug_detail   = _dl_strstr(_dl_debug, "detail");
 332                         _dl_debug_move     = _dl_strstr(_dl_debug, "move");
 333                         _dl_debug_symbols  = _dl_strstr(_dl_debug, "sym");
 334                         _dl_debug_reloc    = _dl_strstr(_dl_debug, "reloc");
 335                         _dl_debug_nofixups = _dl_strstr(_dl_debug, "nofix");
 336                         _dl_debug_bindings = _dl_strstr(_dl_debug, "bind");
 337                 }
 338         }
 339
 340         {
 341                 const char *dl_debug_output;
 342
 343                 dl_debug_output = _dl_getenv("LD_DEBUG_OUTPUT", envp);
 344
 345                 if (dl_debug_output) {
 346                         char tmp[22], *tmp1, *filename;
 347                         int len1, len2;
 348
 349                         _dl_memset(tmp, 0, sizeof(tmp));
 350                         tmp1 = _dl_simple_ltoa( tmp, (unsigned long)_dl_getpid());
 351
 352                         len1 = _dl_strlen(dl_debug_output);
 353                         len2 = _dl_strlen(tmp1);
 354
 355                         filename = _dl_malloc(len1+len2+2);
 356
 357                         if (filename) {
 358                                 _dl_strcpy (filename, dl_debug_output);
 359                                 filename[len1] = '.';
 360                                 _dl_strcpy (&filename[len1+1], tmp1);
 361
 362                                 _dl_debug_file= _dl_open(filename, O_WRONLY|O_CREAT, 0644);
 363                                 if (_dl_debug_file < 0) {
 364                                         _dl_debug_file = 2;
 365                                         _dl_dprintf(_dl_debug_file, "can't open file: '%s'\n",filename);
 366                                 }
 367                         }
 368                 }
 369         }
 370 #endif
 371
 372         if (_dl_getenv("LD_TRACE_LOADED_OBJECTS", envp) != NULL) {
 373                 trace_loaded_objects++;
 374         }
 375
 376 #ifndef __LDSO_LDD_SUPPORT__
 377         if (trace_loaded_objects) {
 378                 _dl_dprintf(_dl_debug_file, "Use the ldd provided by uClibc\n");
 379                 _dl_exit(1);
 380         }
 381 #endif
 382
 383         /*
 384          * OK, fix one more thing - set up debug_addr so it will point
 385          * to our chain.  Later we may need to fill in more fields, but this
 386          * should be enough for now.
 387          */
 388         debug_addr->r_map = (struct link_map *) _dl_loaded_modules;
 389         debug_addr->r_version = 1;
 390         debug_addr->r_ldbase = load_addr;
 391         debug_addr->r_brk = (unsigned long) &_dl_debug_state;
 392         _dl_debug_addr = debug_addr;
 393
 394         /* Notify the debugger we are in a consistant state */
 395         _dl_debug_addr->r_state = RT_CONSISTENT;
 396         _dl_debug_state();
 397
 398         /* OK, we now have the application in the list, and we have some
 399          * basic stuff in place.  Now search through the list for other shared
 400          * libraries that should be loaded, and insert them on the list in the
 401          * correct order.
 402          */
 403
 404         _dl_map_cache();
 405
 406         if (_dl_preload) {
 407                 char c, *str, *str2;
 408
 409                 str = _dl_preload;
 410                 while (*str == ':' || *str == ' ' || *str == '\t')
 411                         str++;
 412
 413                 while (*str) {
 414                         str2 = str;
 415                         while (*str2 && *str2 != ':' && *str2 != ' ' && *str2 != '\t')
 416                                 str2++;
 417                         c = *str2;
 418                         *str2 = '\0';
 419
 420                         if (!_dl_secure || _dl_strchr(str, '/') == NULL) {
 421                                 _dl_if_debug_dprint("\tfile='%s';  needed by '%s'\n", str, _dl_progname);
 422
 423                                 tpnt1 = _dl_load_shared_library(_dl_secure, &rpnt, NULL, str, trace_loaded_objects);
 424                                 if (!tpnt1) {
 425 #ifdef __LDSO_LDD_SUPPORT__
 426                                         if (trace_loaded_objects)
 427                                                 _dl_dprintf(1, "\t%s => not found\n", str);
 428                                         else
 429 #endif
 430                                         {
 431                                                 _dl_dprintf(_dl_debug_file, "%s: can't load " "library '%s'\n", _dl_progname, str);
 432                                                 _dl_exit(15);
 433                                         }
 434                                 } else {
 435                                         tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
 436
 437                                         _dl_debug_early("Loading: (%x) %s\n", tpnt1->loadaddr, tpnt1->libname);
 438
 439 #ifdef __LDSO_LDD_SUPPORT__
 440                                         if (trace_loaded_objects &&
 441                                             tpnt1->usage_count == 1) {
 442                                                 /* This is a real hack to make
 443                                                  * ldd not print the library
 444                                                  * itself when run on a
 445                                                  * library.
 446                                                  */
 447                                                 if (_dl_strcmp(_dl_progname, str) != 0)
 448                                                         _dl_dprintf(1, "\t%s => %s (%x)\n", str, tpnt1->libname,
 449                                                                     tpnt1->loadaddr);
 450                                         }
 451 #endif
 452                                 }
 453                         }
 454
 455                         *str2 = c;
 456                         str = str2;
 457                         while (*str == ':' || *str == ' ' || *str == '\t')
 458                                 str++;
 459                 }
 460         }
 461
 462 #ifdef __LDSO_PRELOAD_FILE_SUPPORT__
 463         do {
 464                 struct stat st;
 465                 char *preload;
 466                 int fd;
 467                 char c, *cp, *cp2;
 468
 469                 if (_dl_stat(LDSO_PRELOAD, &st) || st.st_size == 0) {
 470                         break;
 471                 }
 472
 473                 if ((fd = _dl_open(LDSO_PRELOAD, O_RDONLY, 0)) < 0) {
 474                         _dl_dprintf(_dl_debug_file, "%s: can't open file '%s'\n",
 475                                     _dl_progname, LDSO_PRELOAD);
 476                         break;
 477                 }
 478
 479                 preload = (caddr_t) _dl_mmap(0, st.st_size + 1,
 480                                              PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
 481                 _dl_close(fd);
 482                 if (preload == (caddr_t) -1) {
 483                         _dl_dprintf(_dl_debug_file, "%s: can't map file '%s'\n",
 484                                     _dl_progname, LDSO_PRELOAD);
 485                         break;
 486                 }
 487
 488                 /* convert all separators and comments to spaces */
 489                 for (cp = preload; *cp; /*nada */ ) {
 490                         if (*cp == ':' || *cp == '\t' || *cp == '\n') {
 491                                 *cp++ = ' ';
 492                         } else if (*cp == '#') {
 493                                 do {
 494                                         *cp++ = ' ';
 495                                 } while (*cp != '\n' && *cp != '\0');
 496                         } else {
 497                                 cp++;
 498                         }
 499                 }
 500
 501                 /* find start of first library */
 502                 for (cp = preload; *cp && *cp == ' '; cp++)
 503                         /*nada */ ;
 504
 505                 while (*cp) {
 506                         /* find end of library */
 507                         for (cp2 = cp; *cp && *cp != ' '; cp++)
 508                                 /*nada */ ;
 509                         c = *cp;
 510                         *cp = '\0';
 511
 512                         _dl_if_debug_dprint("\tfile='%s';  needed by '%s'\n", cp2, _dl_progname);
 513
 514                         tpnt1 = _dl_load_shared_library(0, &rpnt, NULL, cp2, trace_loaded_objects);
 515                         if (!tpnt1) {
 516 #ifdef __LDSO_LDD_SUPPORT__
 517                                 if (trace_loaded_objects)
 518                                         _dl_dprintf(1, "\t%s => not found\n", cp2);
 519                                 else
 520 #endif
 521                                 {
 522                                         _dl_dprintf(_dl_debug_file, "%s: can't load library '%s'\n", _dl_progname, cp2);
 523                                         _dl_exit(15);
 524                                 }
 525                         } else {
 526                                 tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
 527
 528                                 _dl_debug_early("Loading: (%x) %s\n", tpnt1->loadaddr, tpnt1->libname);
 529
 530 #ifdef __LDSO_LDD_SUPPORT__
 531                                 if (trace_loaded_objects &&
 532                                     tpnt1->usage_count == 1) {
 533                                         _dl_dprintf(1, "\t%s => %s (%x)\n",
 534                                                     cp2, tpnt1->libname,
 535                                                     (unsigned)tpnt1->loadaddr);
 536                                 }
 537 #endif
 538                         }
 539
 540                         /* find start of next library */
 541                         *cp = c;
 542                         for ( /*nada */ ; *cp && *cp == ' '; cp++)
 543                                 /*nada */ ;
 544                 }
 545
 546                 _dl_munmap(preload, st.st_size + 1);
 547         } while (0);
 548 #endif /* __LDSO_PRELOAD_FILE_SUPPORT__ */
 549
 550         nlist = 0;
 551         for (tcurr = _dl_loaded_modules; tcurr; tcurr = tcurr->next) {
 552                 ElfW(Dyn) *dpnt;
 553
 554                 nlist++;
 555                 for (dpnt = (ElfW(Dyn) *) tcurr->dynamic_addr; dpnt->d_tag; dpnt++) {
 556                         if (dpnt->d_tag == DT_NEEDED) {
 557                                 char *name;
 558                                 struct init_fini_list *tmp;
 559
 560                                 lpntstr = (char*) (tcurr->dynamic_info[DT_STRTAB] + dpnt->d_un.d_val);
 561                                 name = _dl_get_last_path_component(lpntstr);
 562                                 if (_dl_strcmp(name, UCLIBC_LDSO) == 0)
 563                                         continue;
 564
 565                                 _dl_if_debug_dprint("\tfile='%s';  needed by '%s'\n", lpntstr, _dl_progname);
 566
 567                                 if (!(tpnt1 = _dl_load_shared_library(0, &rpnt, tcurr, lpntstr, trace_loaded_objects))) {
 568 #ifdef __LDSO_LDD_SUPPORT__
 569                                         if (trace_loaded_objects) {
 570                                                 _dl_dprintf(1, "\t%s => not found\n", lpntstr);
 571                                                 continue;
 572                                         } else
 573 #endif
 574                                         {
 575                                                 _dl_dprintf(_dl_debug_file, "%s: can't load library '%s'\n", _dl_progname, lpntstr);
 576                                                 _dl_exit(16);
 577                                         }
 578                                 }
 579
 580                                 tmp = alloca(sizeof(struct init_fini_list)); /* Allocates on stack, no need to free this memory */
 581                                 tmp->tpnt = tpnt1;
 582                                 tmp->next = tcurr->init_fini;
 583                                 tcurr->init_fini = tmp;
 584
 585                                 tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
 586
 587                                 _dl_debug_early("Loading: (%x) %s\n", tpnt1->loadaddr, tpnt1->libname);
 588
 589 #ifdef __LDSO_LDD_SUPPORT__
 590                                 if (trace_loaded_objects &&
 591                                     tpnt1->usage_count == 1) {
 592                                         _dl_dprintf(1, "\t%s => %s (%x)\n",
 593                                                     lpntstr, tpnt1->libname,
 594                                                     (unsigned)tpnt1->loadaddr);
 595                                 }
 596 #endif
 597                         }
 598                 }
 599         }
 600         _dl_unmap_cache();
 601
 602         --nlist; /* Exclude the application. */
 603         init_fini_list = _dl_malloc(nlist * sizeof(struct elf_resolve *));
 604         i = 0;
 605         for (tcurr = _dl_loaded_modules->next; tcurr; tcurr = tcurr->next) {
 606                 init_fini_list[i++] = tcurr;
 607         }
 608
 609         /* Sort the INIT/FINI list in dependency order. */
 610         for (tcurr = _dl_loaded_modules->next; tcurr; tcurr = tcurr->next) {
 611                 int j, k;
 612
 613                 for (j = 0; init_fini_list[j] != tcurr; ++j)
 614                         /* Empty */;
 615                 for (k = j + 1; k < nlist; ++k) {
 616                         struct init_fini_list *runp = init_fini_list[k]->init_fini;
 617
 618                         for (; runp; runp = runp->next) {
 619                                 if (runp->tpnt == tcurr) {
 620                                         struct elf_resolve *here = init_fini_list[k];
 621                                         _dl_if_debug_dprint("Move %s from pos %d to %d in INIT/FINI list\n", here->libname, k, j);
 622                                         for (i = (k - j); i; --i)
 623                                                 init_fini_list[i+j] = init_fini_list[i+j-1];
 624                                         init_fini_list[j] = here;
 625                                         ++j;
 626                                         break;
 627                                 }
 628                         }
 629                 }
 630         }
 631 #ifdef __SUPPORT_LD_DEBUG__
 632         if(_dl_debug) {
 633                 _dl_dprintf(_dl_debug_file, "\nINIT/FINI order and dependencies:\n");
 634                 for (i = 0; i < nlist; i++) {
 635                         struct init_fini_list *tmp;
 636
 637                         _dl_dprintf(_dl_debug_file, "lib: %s has deps:\n",
 638                                     init_fini_list[i]->libname);
 639                         tmp = init_fini_list[i]->init_fini;
 640                         for (; tmp; tmp = tmp->next)
 641                                 _dl_dprintf(_dl_debug_file, " %s ", tmp->tpnt->libname);
 642                         _dl_dprintf(_dl_debug_file, "\n");
 643                 }
 644         }
 645 #endif
 646
 647         /*
 648          * If the program interpreter is not in the module chain, add it.
 649          * This will be required for dlopen to be able to access the internal
 650          * functions in the dynamic linker and to relocate the interpreter
 651          * again once all libs are loaded.
 652          */
 653         if (tpnt) {
 654                 ElfW(Ehdr) *epnt = (ElfW(Ehdr) *) auxvt[AT_BASE].a_un.a_val;
 655                 ElfW(Phdr) *myppnt = (ElfW(Phdr) *) (load_addr + epnt->e_phoff);
 656                 int j;
 657
 658                 tpnt = _dl_add_elf_hash_table(tpnt->libname, (char *)load_addr,
 659                                               tpnt->dynamic_info,
 660                                               (unsigned long)tpnt->dynamic_addr,
 661                                               0);
 662
 663                 tpnt->n_phent = epnt->e_phnum;
 664                 tpnt->ppnt = myppnt;
 665                 for (j = 0; j < epnt->e_phnum; j++, myppnt++) {
 666                         if (myppnt->p_type ==  PT_GNU_RELRO) {
 667                                 tpnt->relro_addr = myppnt->p_vaddr;
 668                                 tpnt->relro_size = myppnt->p_memsz;
 669                                 break;
 670                         }
 671                 }
 672                 tpnt->libtype = program_interpreter;
 673                 tpnt->usage_count++;
 674                 tpnt->symbol_scope = _dl_symbol_tables;
 675                 if (rpnt) {
 676                         rpnt->next = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
 677                         _dl_memset(rpnt->next, 0, sizeof(struct dyn_elf));
 678                         rpnt->next->prev = rpnt;
 679                         rpnt = rpnt->next;
 680                 } else {
 681                         rpnt = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
 682                         _dl_memset(rpnt, 0, sizeof(struct dyn_elf));
 683                 }
 684                 rpnt->dyn = tpnt;
 685                 tpnt->rtld_flags = RTLD_NOW | RTLD_GLOBAL; /* Must not be LAZY */
 686 #ifdef RERELOCATE_LDSO
 687                 /* Only rerelocate functions for now. */
 688                 tpnt->init_flag = RELOCS_DONE;
 689                 lpnt = (unsigned long *) (tpnt->dynamic_info[DT_PLTGOT]);
 690 # ifdef ALLOW_ZERO_PLTGOT
 691                 if (tpnt->dynamic_info[DT_PLTGOT])
 692 # endif
 693                         INIT_GOT(lpnt, tpnt);
 694 #else
 695                 tpnt->init_flag = RELOCS_DONE | JMP_RELOCS_DONE;
 696 #endif
 697                 tpnt = NULL;
 698         }
 699
 700 #ifdef __LDSO_LDD_SUPPORT__
 701         /* End of the line for ldd.... */
 702         if (trace_loaded_objects) {
 703                 _dl_dprintf(1, "\t%s => %s (%x)\n",
 704                             rpnt->dyn->libname + _dl_strlen(_dl_ldsopath) + 1,
 705                             rpnt->dyn->libname, rpnt->dyn->loadaddr);
 706                 _dl_exit(0);
 707         }
 708 #endif
 709
 710         _dl_debug_early("Beginning relocation fixups\n");
 711
 712 #ifdef __mips__
 713         /*
 714          * Relocation of the GOT entries for MIPS have to be done
 715          * after all the libraries have been loaded.
 716          */
 717         _dl_perform_mips_global_got_relocations(_dl_loaded_modules, !unlazy);
 718 #endif
 719
 720         /*
 721          * OK, now all of the kids are tucked into bed in their proper
 722          * addresses.  Now we go through and look for REL and RELA records that
 723          * indicate fixups to the GOT tables.  We need to do this in reverse
 724          * order so that COPY directives work correctly.
 725          */
 726         if (_dl_symbol_tables)
 727                 if (_dl_fixup(_dl_symbol_tables, unlazy))
 728                         _dl_exit(-1);
 729
 730         for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
 731                 if (tpnt->relro_size)
 732                         _dl_protect_relro (tpnt);
 733         }
 734
 735         /* OK, at this point things are pretty much ready to run.  Now we need
 736          * to touch up a few items that are required, and then we can let the
 737          * user application have at it.  Note that the dynamic linker itself
 738          * is not guaranteed to be fully dynamicly linked if we are using
 739          * ld.so.1, so we have to look up each symbol individually.
 740          */
 741
 742         _dl_envp = (unsigned long *) (intptr_t) _dl_find_hash("__environ", _dl_symbol_tables, NULL, 0);
 743         if (_dl_envp)
 744                 *_dl_envp = (unsigned long) envp;
 745
 746 #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
 747         {
 748                 unsigned int j;
 749                 ElfW(Phdr) *myppnt;
 750
 751                 /* We had to set the protections of all pages to R/W for
 752                  * dynamic linking.  Set text pages back to R/O.
 753                  */
 754                 for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
 755                         for (myppnt = tpnt->ppnt, j = 0; j < tpnt->n_phent; j++, myppnt++) {
 756                                 if (myppnt->p_type == PT_LOAD && !(myppnt->p_flags & PF_W) && tpnt->dynamic_info[DT_TEXTREL]) {
 757                                         _dl_mprotect((void *) (tpnt->loadaddr + (myppnt->p_vaddr & PAGE_ALIGN)),
 758                                                         (myppnt->p_vaddr & ADDR_ALIGN) + (unsigned long) myppnt->p_filesz, LXFLAGS(myppnt->p_flags));
 759                                 }
 760                         }
 761                 }
 762
 763         }
 764 #endif
 765         /* Notify the debugger we have added some objects. */
 766         _dl_debug_addr->r_state = RT_ADD;
 767         _dl_debug_state();
 768         for (i = nlist; i; --i) {
 769                 tpnt = init_fini_list[i-1];
 770                 tpnt->init_fini = NULL; /* Clear, since alloca was used */
 771                 if (tpnt->init_flag & INIT_FUNCS_CALLED)
 772                         continue;
 773                 tpnt->init_flag |= INIT_FUNCS_CALLED;
 774
 775                 if (tpnt->dynamic_info[DT_INIT]) {
 776                         void (*dl_elf_func) (void);
 777
 778                         dl_elf_func = (void (*)(void)) (intptr_t) (tpnt->loadaddr + tpnt->dynamic_info[DT_INIT]);
 779
 780                         _dl_if_debug_dprint("calling INIT: %s\n\n", tpnt->libname);
 781
 782                         (*dl_elf_func) ();
 783                 }
 784         }
 785
 786         /* Find the real malloc function and make ldso functions use that from now on */
 787          _dl_malloc_function = (void* (*)(size_t)) (intptr_t) _dl_find_hash("malloc",
 788                          _dl_symbol_tables, NULL, ELF_RTYPE_CLASS_PLT);
 789
 790         /* Notify the debugger that all objects are now mapped in.  */
 791         _dl_debug_addr->r_state = RT_CONSISTENT;
 792         _dl_debug_state();
 793 }
 794
 795 char *_dl_getenv(const char *symbol, char **envp)
 796 {
 797         char *pnt;
 798         const char *pnt1;
 799
 800         while ((pnt = *envp++)) {
 801                 pnt1 = symbol;
 802                 while (*pnt && *pnt == *pnt1)
 803                         pnt1++, pnt++;
 804                 if (!*pnt || *pnt != '=' || *pnt1)
 805                         continue;
 806                 return pnt + 1;
 807         }
 808         return 0;
 809 }
 810
 811 void _dl_unsetenv(const char *symbol, char **envp)
 812 {
 813         char *pnt;
 814         const char *pnt1;
 815         char **newenvp = envp;
 816
 817         for (pnt = *envp; pnt; pnt = *++envp) {
 818                 pnt1 = symbol;
 819                 while (*pnt && *pnt == *pnt1)
 820                         pnt1++, pnt++;
 821                 if (!*pnt || *pnt != '=' || *pnt1)
 822                         *newenvp++ = *envp;
 823         }
 824         *newenvp++ = *envp;
 825         return;
 826 }
 827
 828 static int _dl_suid_ok(void)
 829 {
 830         __kernel_uid_t uid, euid;
 831         __kernel_gid_t gid, egid;
 832
 833         uid = _dl_getuid();
 834         euid = _dl_geteuid();
 835         gid = _dl_getgid();
 836         egid = _dl_getegid();
 837
 838         if(uid == euid && gid == egid) {
 839                 return 1;
 840         }
 841         return 0;
 842 }
 843
 844 void *_dl_malloc(int size)
 845 {
 846         void *retval;
 847
 848 #if 0
 849         _dl_debug_early("request for %d bytes\n", size);
 850 #endif
 851
 852         if (_dl_malloc_function)
 853                 return (*_dl_malloc_function) (size);
 854
 855         if (_dl_malloc_addr - _dl_mmap_zero + (unsigned)size > _dl_pagesize) {
 856                 _dl_debug_early("mmapping more memory\n");
 857                 _dl_mmap_zero = _dl_malloc_addr = _dl_mmap((void *) 0, size,
 858                                 PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 859                 if (_dl_mmap_check_error(_dl_mmap_zero)) {
 860                         _dl_dprintf(_dl_debug_file, "%s: mmap of a spare page failed!\n", _dl_progname);
 861                         _dl_exit(20);
 862                 }
 863         }
 864         retval = _dl_malloc_addr;
 865         _dl_malloc_addr += size;
 866
 867         /*
 868          * Align memory to 4 byte boundary.  Some platforms require this,
 869          * others simply get better performance.
 870          */
 871         _dl_malloc_addr = (unsigned char *) (((unsigned long) _dl_malloc_addr + 3) & ~(3));
 872         return retval;
 873 }
 874
 875 #include "dl-hash.c"
 876 #include "dl-elf.c"