ldso/ldso/ldso.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Program to load an ELF binary on a linux system, and run it
   4  * after resolving ELF shared library symbols
   5  *
   6  * Copyright (C) 2005 by Joakim Tjernlund
   7  * Copyright (C) 2000-2004 by Erik Andersen <andersen@codepoet.org>
   8  * Copyright (c) 1994-2000 Eric Youngdale, Peter MacDonald,
   9  *                              David Engel, Hongjiu Lu and Mitch D'Souza
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions and the following disclaimer.
  16  * 2. The name of the above contributors may not be
  17  *    used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33 #include "ldso.h"
  34 #include "unsecvars.h"
  35
  36 /* Pull in common debug code */
  37 #include "dl-debug.c"
  38
  39 #define ALLOW_ZERO_PLTGOT
  40
  41 /* Pull in the value of _dl_progname */
  42 #include LDSO_ELFINTERP
  43
  44 /* Global variables used within the shared library loader */
  45 char *_dl_library_path         = 0;     /* Where we look for libraries */
  46 char *_dl_preload              = 0;     /* Things to be loaded before the libs */
  47 char *_dl_ldsopath             = 0;     /* Location of the shared lib loader */
  48 int _dl_secure                 = 1;     /* Are we dealing with setuid stuff? */
  49 int _dl_errno                  = 0;     /* We can't use the real errno in ldso */
  50 size_t _dl_pagesize            = 0;     /* Store the page size for use later */
  51 struct r_debug *_dl_debug_addr = NULL;  /* Used to communicate with the gdb debugger */
  52 void *(*_dl_malloc_function) (size_t size) = NULL;
  53
  54 #ifdef __SUPPORT_LD_DEBUG__
  55 char *_dl_debug           = 0;
  56 char *_dl_debug_symbols   = 0;
  57 char *_dl_debug_move      = 0;
  58 char *_dl_debug_reloc     = 0;
  59 char *_dl_debug_detail    = 0;
  60 char *_dl_debug_nofixups  = 0;
  61 char *_dl_debug_bindings  = 0;
  62 int   _dl_debug_file      = 2;
  63 #endif
  64
  65 /* Needed for standalone execution. */
  66 unsigned long attribute_hidden _dl_skip_args = 0;
  67 const char *_dl_progname = UCLIBC_LDSO;      /* The name of the executable being run */
  68 #include "dl-startup.c"
  69 /* Forward function declarations */
  70 static int _dl_suid_ok(void);
  71
  72 /*
  73  * This stub function is used by some debuggers.  The idea is that they
  74  * can set an internal breakpoint on it, so that we are notified when the
  75  * address mapping is changed in some way.
  76  */
  77 void _dl_debug_state(void);
  78 void _dl_debug_state()
  79 {
  80 }
  81
  82 static unsigned char *_dl_malloc_addr = 0;      /* Lets _dl_malloc use the already allocated memory page */
  83 static unsigned char *_dl_mmap_zero   = 0;      /* Also used by _dl_malloc */
  84
  85 static struct elf_resolve **init_fini_list;
  86 static unsigned int nlist; /* # items in init_fini_list */
  87 extern void _start(void);
  88
  89 #ifdef __UCLIBC_HAS_SSP__
  90 #include <dl-osinfo.h>
  91 #ifndef THREAD_SET_STACK_GUARD
  92 /* Only exported for architectures that don't store the stack guard canary
  93  * in local thread area.  */
  94 uintptr_t __stack_chk_guard attribute_relro;
  95 strong_alias(__stack_chk_guard,__guard)
  96 #endif
  97 #endif
  98
  99 static void __attribute__ ((destructor)) __attribute_used__ _dl_fini(void)
 100 {
 101         int i;
 102         struct elf_resolve * tpnt;
 103
 104         for (i = 0; i < nlist; ++i) {
 105                 tpnt = init_fini_list[i];
 106                 if (tpnt->init_flag & FINI_FUNCS_CALLED)
 107                         continue;
 108                 tpnt->init_flag |= FINI_FUNCS_CALLED;
 109                 if (tpnt->dynamic_info[DT_FINI]) {
 110                         void (*dl_elf_func) (void);
 111
 112                         dl_elf_func = (void (*)(void)) (intptr_t) (tpnt->loadaddr + tpnt->dynamic_info[DT_FINI]);
 113                         _dl_if_debug_dprint("\ncalling FINI: %s\n\n", tpnt->libname);
 114                         (*dl_elf_func) ();
 115                 }
 116         }
 117 }
 118
 119 void _dl_get_ready_to_run(struct elf_resolve *tpnt, unsigned long load_addr,
 120                           ElfW(auxv_t) auxvt[AT_EGID + 1], char **envp,
 121                           char **argv)
 122 {
 123         ElfW(Phdr) *ppnt;
 124         ElfW(Dyn) *dpnt;
 125         char *lpntstr;
 126         unsigned int i;
 127         int unlazy = 0, trace_loaded_objects = 0;
 128         struct dyn_elf *rpnt;
 129         struct elf_resolve *tcurr;
 130         struct elf_resolve *tpnt1;
 131         struct elf_resolve app_tpnt_tmp;
 132         struct elf_resolve *app_tpnt = &app_tpnt_tmp;
 133         struct r_debug *debug_addr;
 134         unsigned long *lpnt;
 135         unsigned long *_dl_envp;                /* The environment address */
 136         ElfW(Addr) relro_addr = 0;
 137         size_t relro_size = 0;
 138
 139         /* Wahoo!!! We managed to make a function call!  Get malloc
 140          * setup so we can use _dl_dprintf() to print debug noise
 141          * instead of the SEND_STDERR macros used in dl-startup.c */
 142
 143         _dl_memset(app_tpnt, 0x00, sizeof(*app_tpnt));
 144
 145         /* Store the page size for later use */
 146         _dl_pagesize = (auxvt[AT_PAGESZ].a_un.a_val) ? (size_t) auxvt[AT_PAGESZ].a_un.a_val : PAGE_SIZE;
 147         /* Make it so _dl_malloc can use the page of memory we have already
 148          * allocated.  We shouldn't need to grab any more memory.  This must
 149          * be first since things like _dl_dprintf() use _dl_malloc()...
 150          */
 151         _dl_malloc_addr = (unsigned char *)_dl_pagesize;
 152         _dl_mmap_zero = 0;
 153
 154         /* Wahoo!!! */
 155         _dl_debug_early("Cool, ldso survived making function calls\n");
 156
 157         /* Now we have done the mandatory linking of some things.  We are now
 158          * free to start using global variables, since these things have all
 159          * been fixed up by now.  Still no function calls outside of this
 160          * library, since the dynamic resolver is not yet ready.
 161          */
 162         if (argv[0]) {
 163                 _dl_progname = argv[0];
 164         }
 165
 166         if (_start == (void *) auxvt[AT_ENTRY].a_un.a_val) {
 167                 _dl_dprintf(_dl_debug_file, "Standalone execution is not supported yet\n");
 168                 _dl_exit(1);
 169         }
 170
 171         /* Start to build the tables of the modules that are required for
 172          * this beast to run.  We start with the basic executable, and then
 173          * go from there.  Eventually we will run across ourself, and we
 174          * will need to properly deal with that as well.
 175          */
 176         rpnt = NULL;
 177         if (_dl_getenv("LD_BIND_NOW", envp))
 178                 unlazy = RTLD_NOW;
 179
 180         /* Now we need to figure out what kind of options are selected.
 181          * Note that for SUID programs we ignore the settings in
 182          * LD_LIBRARY_PATH.
 183          */
 184         if ((auxvt[AT_UID].a_un.a_val == (size_t)-1 && _dl_suid_ok()) ||
 185             (auxvt[AT_UID].a_un.a_val != (size_t)-1 &&
 186              auxvt[AT_UID].a_un.a_val == auxvt[AT_EUID].a_un.a_val &&
 187              auxvt[AT_GID].a_un.a_val == auxvt[AT_EGID].a_un.a_val)) {
 188                 _dl_secure = 0;
 189                 _dl_preload = _dl_getenv("LD_PRELOAD", envp);
 190                 _dl_library_path = _dl_getenv("LD_LIBRARY_PATH", envp);
 191         } else {
 192                 static const char unsecure_envvars[] =
 193 #ifdef EXTRA_UNSECURE_ENVVARS
 194                         EXTRA_UNSECURE_ENVVARS
 195 #endif
 196                         UNSECURE_ENVVARS;
 197                 const char *nextp;
 198                 _dl_secure = 1;
 199
 200                 nextp = unsecure_envvars;
 201                 do {
 202                         _dl_unsetenv (nextp, envp);
 203                         /* We could use rawmemchr but this need not be fast.  */
 204                         nextp = (char *) _dl_strchr(nextp, '\0') + 1;
 205                 } while (*nextp != '\0');
 206                 _dl_preload = NULL;
 207                 _dl_library_path = NULL;
 208                 /* SUID binaries can be exploited if they do LAZY relocation. */
 209                 unlazy = RTLD_NOW;
 210         }
 211
 212         /* sjhill: your TLS init should go before this */
 213 #ifdef __UCLIBC_HAS_SSP__
 214         /* Set up the stack checker's canary.  */
 215         uintptr_t stack_chk_guard = _dl_setup_stack_chk_guard ();
 216 # ifdef THREAD_SET_STACK_GUARD
 217         THREAD_SET_STACK_GUARD (stack_chk_guard);
 218 # else
 219         __stack_chk_guard = stack_chk_guard;
 220 # endif
 221 #endif
 222
 223         /* At this point we are now free to examine the user application,
 224          * and figure out which libraries are supposed to be called.  Until
 225          * we have this list, we will not be completely ready for dynamic
 226          * linking.
 227          */
 228
 229         /* Find the runtime load address of the main executable.  This may be
 230          * different from what the ELF header says for ET_DYN/PIE executables.
 231          */
 232         {
 233                 unsigned int i;
 234                 ElfW(Phdr) *ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
 235
 236                 for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++)
 237                         if (ppnt->p_type == PT_PHDR) {
 238                                 app_tpnt->loadaddr = (ElfW(Addr)) (auxvt[AT_PHDR].a_un.a_val - ppnt->p_vaddr);
 239                                 break;
 240                         }
 241
 242                 if (app_tpnt->loadaddr)
 243                         _dl_debug_early("Position Independent Executable: "
 244                                         "app_tpnt->loadaddr=%x\n", app_tpnt->loadaddr);
 245         }
 246
 247         /*
 248          * This is used by gdb to locate the chain of shared libraries that are
 249          * currently loaded.
 250          */
 251         debug_addr = _dl_malloc(sizeof(struct r_debug));
 252         _dl_memset(debug_addr, 0, sizeof(struct r_debug));
 253
 254         ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
 255         for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++) {
 256                 if (ppnt->p_type == PT_GNU_RELRO) {
 257                         relro_addr = ppnt->p_vaddr;
 258                         relro_size = ppnt->p_memsz;
 259                 }
 260                 if (ppnt->p_type == PT_DYNAMIC) {
 261                         dpnt = (ElfW(Dyn) *) (ppnt->p_vaddr + app_tpnt->loadaddr);
 262                         _dl_parse_dynamic_info(dpnt, app_tpnt->dynamic_info, debug_addr, app_tpnt->loadaddr);
 263 #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
 264                         /* Ugly, ugly.  We need to call mprotect to change the
 265                          * protection of the text pages so that we can do the
 266                          * dynamic linking.  We can set the protection back
 267                          * again once we are done.
 268                          */
 269                         _dl_debug_early("calling mprotect on the application program\n");
 270                         /* Now cover the application program. */
 271                         if (app_tpnt->dynamic_info[DT_TEXTREL]) {
 272                                 ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
 273                                 for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++) {
 274                                         if (ppnt->p_type == PT_LOAD && !(ppnt->p_flags & PF_W))
 275                                                 _dl_mprotect((void *) ((ppnt->p_vaddr + app_tpnt->loadaddr) & PAGE_ALIGN),
 276                                                              ((ppnt->p_vaddr + app_tpnt->loadaddr) & ADDR_ALIGN) +
 277                                                              (unsigned long) ppnt->p_filesz,
 278                                                              PROT_READ | PROT_WRITE | PROT_EXEC);
 279                                 }
 280                         }
 281 #endif
 282
 283 #ifndef ALLOW_ZERO_PLTGOT
 284                         /* make sure it's really there. */
 285                         if (app_tpnt->dynamic_info[DT_PLTGOT] == 0)
 286                                 continue;
 287 #endif
 288                         /* OK, we have what we need - slip this one into the list. */
 289                         app_tpnt = _dl_add_elf_hash_table(_dl_progname, (char *)app_tpnt->loadaddr,
 290                                         app_tpnt->dynamic_info, ppnt->p_vaddr + app_tpnt->loadaddr, ppnt->p_filesz);
 291                         _dl_loaded_modules->libtype = elf_executable;
 292                         _dl_loaded_modules->ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
 293                         _dl_loaded_modules->n_phent = auxvt[AT_PHNUM].a_un.a_val;
 294                         _dl_symbol_tables = rpnt = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
 295                         _dl_memset(rpnt, 0, sizeof(struct dyn_elf));
 296                         rpnt->dyn = _dl_loaded_modules;
 297                         app_tpnt->rtld_flags = unlazy | RTLD_GLOBAL;
 298                         app_tpnt->usage_count++;
 299                         app_tpnt->symbol_scope = _dl_symbol_tables;
 300                         lpnt = (unsigned long *) (app_tpnt->dynamic_info[DT_PLTGOT]);
 301 #ifdef ALLOW_ZERO_PLTGOT
 302                         if (lpnt)
 303 #endif
 304                                 INIT_GOT(lpnt, _dl_loaded_modules);
 305                 }
 306
 307                 /* OK, fill this in - we did not have this before */
 308                 if (ppnt->p_type == PT_INTERP) {
 309                         char *ptmp;
 310
 311                         tpnt->libname = (char *) ppnt->p_vaddr + app_tpnt->loadaddr;
 312
 313                         /* Store the path where the shared lib loader was found
 314                          * for later use
 315                          */
 316                         _dl_ldsopath = _dl_strdup(tpnt->libname);
 317                         ptmp = _dl_strrchr(_dl_ldsopath, '/');
 318                         if (ptmp != _dl_ldsopath)
 319                                 *ptmp = '\0';
 320
 321                         _dl_debug_early("Lib Loader: (%x) %s\n", tpnt->loadaddr, tpnt->libname);
 322                 }
 323         }
 324         app_tpnt->relro_addr = relro_addr;
 325         app_tpnt->relro_size = relro_size;
 326
 327 #ifdef __SUPPORT_LD_DEBUG__
 328         _dl_debug = _dl_getenv("LD_DEBUG", envp);
 329         if (_dl_debug) {
 330                 if (_dl_strstr(_dl_debug, "all")) {
 331                         _dl_debug_detail = _dl_debug_move = _dl_debug_symbols
 332                                 = _dl_debug_reloc = _dl_debug_bindings = _dl_debug_nofixups = (void*)1;
 333                 } else {
 334                         _dl_debug_detail   = _dl_strstr(_dl_debug, "detail");
 335                         _dl_debug_move     = _dl_strstr(_dl_debug, "move");
 336                         _dl_debug_symbols  = _dl_strstr(_dl_debug, "sym");
 337                         _dl_debug_reloc    = _dl_strstr(_dl_debug, "reloc");
 338                         _dl_debug_nofixups = _dl_strstr(_dl_debug, "nofix");
 339                         _dl_debug_bindings = _dl_strstr(_dl_debug, "bind");
 340                 }
 341         }
 342
 343         {
 344                 const char *dl_debug_output;
 345
 346                 dl_debug_output = _dl_getenv("LD_DEBUG_OUTPUT", envp);
 347
 348                 if (dl_debug_output) {
 349                         char tmp[22], *tmp1, *filename;
 350                         int len1, len2;
 351
 352                         _dl_memset(tmp, 0, sizeof(tmp));
 353                         tmp1 = _dl_simple_ltoa( tmp, (unsigned long)_dl_getpid());
 354
 355                         len1 = _dl_strlen(dl_debug_output);
 356                         len2 = _dl_strlen(tmp1);
 357
 358                         filename = _dl_malloc(len1+len2+2);
 359
 360                         if (filename) {
 361                                 _dl_strcpy (filename, dl_debug_output);
 362                                 filename[len1] = '.';
 363                                 _dl_strcpy (&filename[len1+1], tmp1);
 364
 365                                 _dl_debug_file= _dl_open(filename, O_WRONLY|O_CREAT, 0644);
 366                                 if (_dl_debug_file < 0) {
 367                                         _dl_debug_file = 2;
 368                                         _dl_dprintf(_dl_debug_file, "can't open file: '%s'\n",filename);
 369                                 }
 370                         }
 371                 }
 372         }
 373 #endif
 374
 375         if (_dl_getenv("LD_TRACE_LOADED_OBJECTS", envp) != NULL) {
 376                 trace_loaded_objects++;
 377         }
 378
 379 #ifndef __LDSO_LDD_SUPPORT__
 380         if (trace_loaded_objects) {
 381                 _dl_dprintf(_dl_debug_file, "Use the ldd provided by uClibc\n");
 382                 _dl_exit(1);
 383         }
 384 #endif
 385
 386         /*
 387          * OK, fix one more thing - set up debug_addr so it will point
 388          * to our chain.  Later we may need to fill in more fields, but this
 389          * should be enough for now.
 390          */
 391         debug_addr->r_map = (struct link_map *) _dl_loaded_modules;
 392         debug_addr->r_version = 1;
 393         debug_addr->r_ldbase = load_addr;
 394         debug_addr->r_brk = (unsigned long) &_dl_debug_state;
 395         _dl_debug_addr = debug_addr;
 396
 397         /* Notify the debugger we are in a consistant state */
 398         _dl_debug_addr->r_state = RT_CONSISTENT;
 399         _dl_debug_state();
 400
 401         /* OK, we now have the application in the list, and we have some
 402          * basic stuff in place.  Now search through the list for other shared
 403          * libraries that should be loaded, and insert them on the list in the
 404          * correct order.
 405          */
 406
 407         _dl_map_cache();
 408
 409         if (_dl_preload) {
 410                 char c, *str, *str2;
 411
 412                 str = _dl_preload;
 413                 while (*str == ':' || *str == ' ' || *str == '\t')
 414                         str++;
 415
 416                 while (*str) {
 417                         str2 = str;
 418                         while (*str2 && *str2 != ':' && *str2 != ' ' && *str2 != '\t')
 419                                 str2++;
 420                         c = *str2;
 421                         *str2 = '\0';
 422
 423                         if (!_dl_secure || _dl_strchr(str, '/') == NULL) {
 424                                 _dl_if_debug_dprint("\tfile='%s';  needed by '%s'\n", str, _dl_progname);
 425
 426                                 tpnt1 = _dl_load_shared_library(_dl_secure, &rpnt, NULL, str, trace_loaded_objects);
 427                                 if (!tpnt1) {
 428 #ifdef __LDSO_LDD_SUPPORT__
 429                                         if (trace_loaded_objects)
 430                                                 _dl_dprintf(1, "\t%s => not found\n", str);
 431                                         else
 432 #endif
 433                                         {
 434                                                 _dl_dprintf(_dl_debug_file, "%s: can't load " "library '%s'\n", _dl_progname, str);
 435                                                 _dl_exit(15);
 436                                         }
 437                                 } else {
 438                                         tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
 439
 440                                         _dl_debug_early("Loading: (%x) %s\n", tpnt1->loadaddr, tpnt1->libname);
 441
 442 #ifdef __LDSO_LDD_SUPPORT__
 443                                         if (trace_loaded_objects &&
 444                                             tpnt1->usage_count == 1) {
 445                                                 /* This is a real hack to make
 446                                                  * ldd not print the library
 447                                                  * itself when run on a
 448                                                  * library.
 449                                                  */
 450                                                 if (_dl_strcmp(_dl_progname, str) != 0)
 451                                                         _dl_dprintf(1, "\t%s => %s (%x)\n", str, tpnt1->libname,
 452                                                                     tpnt1->loadaddr);
 453                                         }
 454 #endif
 455                                 }
 456                         }
 457
 458                         *str2 = c;
 459                         str = str2;
 460                         while (*str == ':' || *str == ' ' || *str == '\t')
 461                                 str++;
 462                 }
 463         }
 464
 465 #ifdef __LDSO_PRELOAD_FILE_SUPPORT__
 466         do {
 467                 struct stat st;
 468                 char *preload;
 469                 int fd;
 470                 char c, *cp, *cp2;
 471
 472                 if (_dl_stat(LDSO_PRELOAD, &st) || st.st_size == 0) {
 473                         break;
 474                 }
 475
 476                 if ((fd = _dl_open(LDSO_PRELOAD, O_RDONLY, 0)) < 0) {
 477                         _dl_dprintf(_dl_debug_file, "%s: can't open file '%s'\n",
 478                                     _dl_progname, LDSO_PRELOAD);
 479                         break;
 480                 }
 481
 482                 preload = (caddr_t) _dl_mmap(0, st.st_size + 1,
 483                                              PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
 484                 _dl_close(fd);
 485                 if (preload == (caddr_t) -1) {
 486                         _dl_dprintf(_dl_debug_file, "%s: can't map file '%s'\n",
 487                                     _dl_progname, LDSO_PRELOAD);
 488                         break;
 489                 }
 490
 491                 /* convert all separators and comments to spaces */
 492                 for (cp = preload; *cp; /*nada */ ) {
 493                         if (*cp == ':' || *cp == '\t' || *cp == '\n') {
 494                                 *cp++ = ' ';
 495                         } else if (*cp == '#') {
 496                                 do {
 497                                         *cp++ = ' ';
 498                                 } while (*cp != '\n' && *cp != '\0');
 499                         } else {
 500                                 cp++;
 501                         }
 502                 }
 503
 504                 /* find start of first library */
 505                 for (cp = preload; *cp && *cp == ' '; cp++)
 506                         /*nada */ ;
 507
 508                 while (*cp) {
 509                         /* find end of library */
 510                         for (cp2 = cp; *cp && *cp != ' '; cp++)
 511                                 /*nada */ ;
 512                         c = *cp;
 513                         *cp = '\0';
 514
 515                         _dl_if_debug_dprint("\tfile='%s';  needed by '%s'\n", cp2, _dl_progname);
 516
 517                         tpnt1 = _dl_load_shared_library(0, &rpnt, NULL, cp2, trace_loaded_objects);
 518                         if (!tpnt1) {
 519 #ifdef __LDSO_LDD_SUPPORT__
 520                                 if (trace_loaded_objects)
 521                                         _dl_dprintf(1, "\t%s => not found\n", cp2);
 522                                 else
 523 #endif
 524                                 {
 525                                         _dl_dprintf(_dl_debug_file, "%s: can't load library '%s'\n", _dl_progname, cp2);
 526                                         _dl_exit(15);
 527                                 }
 528                         } else {
 529                                 tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
 530
 531                                 _dl_debug_early("Loading: (%x) %s\n", tpnt1->loadaddr, tpnt1->libname);
 532
 533 #ifdef __LDSO_LDD_SUPPORT__
 534                                 if (trace_loaded_objects &&
 535                                     tpnt1->usage_count == 1) {
 536                                         _dl_dprintf(1, "\t%s => %s (%x)\n",
 537                                                     cp2, tpnt1->libname,
 538                                                     (unsigned)tpnt1->loadaddr);
 539                                 }
 540 #endif
 541                         }
 542
 543                         /* find start of next library */
 544                         *cp = c;
 545                         for ( /*nada */ ; *cp && *cp == ' '; cp++)
 546                                 /*nada */ ;
 547                 }
 548
 549                 _dl_munmap(preload, st.st_size + 1);
 550         } while (0);
 551 #endif /* __LDSO_PRELOAD_FILE_SUPPORT__ */
 552
 553         nlist = 0;
 554         for (tcurr = _dl_loaded_modules; tcurr; tcurr = tcurr->next) {
 555                 ElfW(Dyn) *dpnt;
 556
 557                 nlist++;
 558                 for (dpnt = (ElfW(Dyn) *) tcurr->dynamic_addr; dpnt->d_tag; dpnt++) {
 559                         if (dpnt->d_tag == DT_NEEDED) {
 560                                 char *name;
 561                                 struct init_fini_list *tmp;
 562
 563                                 lpntstr = (char*) (tcurr->dynamic_info[DT_STRTAB] + dpnt->d_un.d_val);
 564                                 name = _dl_get_last_path_component(lpntstr);
 565                                 if (_dl_strcmp(name, UCLIBC_LDSO) == 0)
 566                                         continue;
 567
 568                                 _dl_if_debug_dprint("\tfile='%s';  needed by '%s'\n", lpntstr, _dl_progname);
 569
 570                                 if (!(tpnt1 = _dl_load_shared_library(0, &rpnt, tcurr, lpntstr, trace_loaded_objects))) {
 571 #ifdef __LDSO_LDD_SUPPORT__
 572                                         if (trace_loaded_objects) {
 573                                                 _dl_dprintf(1, "\t%s => not found\n", lpntstr);
 574                                                 continue;
 575                                         } else
 576 #endif
 577                                         {
 578                                                 _dl_dprintf(_dl_debug_file, "%s: can't load library '%s'\n", _dl_progname, lpntstr);
 579                                                 _dl_exit(16);
 580                                         }
 581                                 }
 582
 583                                 tmp = alloca(sizeof(struct init_fini_list)); /* Allocates on stack, no need to free this memory */
 584                                 tmp->tpnt = tpnt1;
 585                                 tmp->next = tcurr->init_fini;
 586                                 tcurr->init_fini = tmp;
 587
 588                                 tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
 589
 590                                 _dl_debug_early("Loading: (%x) %s\n", tpnt1->loadaddr, tpnt1->libname);
 591
 592 #ifdef __LDSO_LDD_SUPPORT__
 593                                 if (trace_loaded_objects &&
 594                                     tpnt1->usage_count == 1) {
 595                                         _dl_dprintf(1, "\t%s => %s (%x)\n",
 596                                                     lpntstr, tpnt1->libname,
 597                                                     (unsigned)tpnt1->loadaddr);
 598                                 }
 599 #endif
 600                         }
 601                 }
 602         }
 603         _dl_unmap_cache();
 604
 605         --nlist; /* Exclude the application. */
 606         init_fini_list = _dl_malloc(nlist * sizeof(struct elf_resolve *));
 607         i = 0;
 608         for (tcurr = _dl_loaded_modules->next; tcurr; tcurr = tcurr->next) {
 609                 init_fini_list[i++] = tcurr;
 610         }
 611
 612         /* Sort the INIT/FINI list in dependency order. */
 613         for (tcurr = _dl_loaded_modules->next; tcurr; tcurr = tcurr->next) {
 614                 int j, k;
 615
 616                 for (j = 0; init_fini_list[j] != tcurr; ++j)
 617                         /* Empty */;
 618                 for (k = j + 1; k < nlist; ++k) {
 619                         struct init_fini_list *runp = init_fini_list[k]->init_fini;
 620
 621                         for (; runp; runp = runp->next) {
 622                                 if (runp->tpnt == tcurr) {
 623                                         struct elf_resolve *here = init_fini_list[k];
 624                                         _dl_if_debug_dprint("Move %s from pos %d to %d in INIT/FINI list\n", here->libname, k, j);
 625                                         for (i = (k - j); i; --i)
 626                                                 init_fini_list[i+j] = init_fini_list[i+j-1];
 627                                         init_fini_list[j] = here;
 628                                         ++j;
 629                                         break;
 630                                 }
 631                         }
 632                 }
 633         }
 634 #ifdef __SUPPORT_LD_DEBUG__
 635         if(_dl_debug) {
 636                 _dl_dprintf(_dl_debug_file, "\nINIT/FINI order and dependencies:\n");
 637                 for (i = 0; i < nlist; i++) {
 638                         struct init_fini_list *tmp;
 639
 640                         _dl_dprintf(_dl_debug_file, "lib: %s has deps:\n",
 641                                     init_fini_list[i]->libname);
 642                         tmp = init_fini_list[i]->init_fini;
 643                         for (; tmp; tmp = tmp->next)
 644                                 _dl_dprintf(_dl_debug_file, " %s ", tmp->tpnt->libname);
 645                         _dl_dprintf(_dl_debug_file, "\n");
 646                 }
 647         }
 648 #endif
 649
 650         /*
 651          * If the program interpreter is not in the module chain, add it.
 652          * This will be required for dlopen to be able to access the internal
 653          * functions in the dynamic linker and to relocate the interpreter
 654          * again once all libs are loaded.
 655          */
 656         if (tpnt) {
 657                 ElfW(Ehdr) *epnt = (ElfW(Ehdr) *) auxvt[AT_BASE].a_un.a_val;
 658                 ElfW(Phdr) *myppnt = (ElfW(Phdr) *) (load_addr + epnt->e_phoff);
 659                 int j;
 660
 661                 tpnt = _dl_add_elf_hash_table(tpnt->libname, (char *)load_addr,
 662                                               tpnt->dynamic_info,
 663                                               (unsigned long)tpnt->dynamic_addr,
 664                                               0);
 665
 666                 tpnt->n_phent = epnt->e_phnum;
 667                 tpnt->ppnt = myppnt;
 668                 for (j = 0; j < epnt->e_phnum; j++, myppnt++) {
 669                         if (myppnt->p_type ==  PT_GNU_RELRO) {
 670                                 tpnt->relro_addr = myppnt->p_vaddr;
 671                                 tpnt->relro_size = myppnt->p_memsz;
 672                                 break;
 673                         }
 674                 }
 675                 tpnt->libtype = program_interpreter;
 676                 tpnt->usage_count++;
 677                 tpnt->symbol_scope = _dl_symbol_tables;
 678                 if (rpnt) {
 679                         rpnt->next = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
 680                         _dl_memset(rpnt->next, 0, sizeof(struct dyn_elf));
 681                         rpnt->next->prev = rpnt;
 682                         rpnt = rpnt->next;
 683                 } else {
 684                         rpnt = (struct dyn_elf *) _dl_malloc(sizeof(struct dyn_elf));
 685                         _dl_memset(rpnt, 0, sizeof(struct dyn_elf));
 686                 }
 687                 rpnt->dyn = tpnt;
 688                 tpnt->rtld_flags = RTLD_NOW | RTLD_GLOBAL; /* Must not be LAZY */
 689 #ifdef RERELOCATE_LDSO
 690                 /* Only rerelocate functions for now. */
 691                 tpnt->init_flag = RELOCS_DONE;
 692                 lpnt = (unsigned long *) (tpnt->dynamic_info[DT_PLTGOT]);
 693 # ifdef ALLOW_ZERO_PLTGOT
 694                 if (tpnt->dynamic_info[DT_PLTGOT])
 695 # endif
 696                         INIT_GOT(lpnt, tpnt);
 697 #else
 698                 tpnt->init_flag = RELOCS_DONE | JMP_RELOCS_DONE;
 699 #endif
 700                 tpnt = NULL;
 701         }
 702
 703 #ifdef __LDSO_LDD_SUPPORT__
 704         /* End of the line for ldd.... */
 705         if (trace_loaded_objects) {
 706                 _dl_dprintf(1, "\t%s => %s (%x)\n",
 707                             rpnt->dyn->libname + _dl_strlen(_dl_ldsopath) + 1,
 708                             rpnt->dyn->libname, rpnt->dyn->loadaddr);
 709                 _dl_exit(0);
 710         }
 711 #endif
 712
 713         _dl_debug_early("Beginning relocation fixups\n");
 714
 715 #ifdef __mips__
 716         /*
 717          * Relocation of the GOT entries for MIPS have to be done
 718          * after all the libraries have been loaded.
 719          */
 720         _dl_perform_mips_global_got_relocations(_dl_loaded_modules, !unlazy);
 721 #endif
 722
 723         /*
 724          * OK, now all of the kids are tucked into bed in their proper
 725          * addresses.  Now we go through and look for REL and RELA records that
 726          * indicate fixups to the GOT tables.  We need to do this in reverse
 727          * order so that COPY directives work correctly.
 728          */
 729         if (_dl_symbol_tables)
 730                 if (_dl_fixup(_dl_symbol_tables, unlazy))
 731                         _dl_exit(-1);
 732
 733         for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
 734                 if (tpnt->relro_size)
 735                         _dl_protect_relro (tpnt);
 736         }
 737
 738         /* OK, at this point things are pretty much ready to run.  Now we need
 739          * to touch up a few items that are required, and then we can let the
 740          * user application have at it.  Note that the dynamic linker itself
 741          * is not guaranteed to be fully dynamicly linked if we are using
 742          * ld.so.1, so we have to look up each symbol individually.
 743          */
 744
 745         _dl_envp = (unsigned long *) (intptr_t) _dl_find_hash("__environ", _dl_symbol_tables, NULL, 0);
 746         if (_dl_envp)
 747                 *_dl_envp = (unsigned long) envp;
 748
 749 #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
 750         {
 751                 unsigned int j;
 752                 ElfW(Phdr) *myppnt;
 753
 754                 /* We had to set the protections of all pages to R/W for
 755                  * dynamic linking.  Set text pages back to R/O.
 756                  */
 757                 for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
 758                         for (myppnt = tpnt->ppnt, j = 0; j < tpnt->n_phent; j++, myppnt++) {
 759                                 if (myppnt->p_type == PT_LOAD && !(myppnt->p_flags & PF_W) && tpnt->dynamic_info[DT_TEXTREL]) {
 760                                         _dl_mprotect((void *) (tpnt->loadaddr + (myppnt->p_vaddr & PAGE_ALIGN)),
 761                                                         (myppnt->p_vaddr & ADDR_ALIGN) + (unsigned long) myppnt->p_filesz, LXFLAGS(myppnt->p_flags));
 762                                 }
 763                         }
 764                 }
 765
 766         }
 767 #endif
 768         /* Notify the debugger we have added some objects. */
 769         _dl_debug_addr->r_state = RT_ADD;
 770         _dl_debug_state();
 771         for (i = nlist; i; --i) {
 772                 tpnt = init_fini_list[i-1];
 773                 tpnt->init_fini = NULL; /* Clear, since alloca was used */
 774                 if (tpnt->init_flag & INIT_FUNCS_CALLED)
 775                         continue;
 776                 tpnt->init_flag |= INIT_FUNCS_CALLED;
 777
 778                 if (tpnt->dynamic_info[DT_INIT]) {
 779                         void (*dl_elf_func) (void);
 780
 781                         dl_elf_func = (void (*)(void)) (intptr_t) (tpnt->loadaddr + tpnt->dynamic_info[DT_INIT]);
 782
 783                         _dl_if_debug_dprint("calling INIT: %s\n\n", tpnt->libname);
 784
 785                         (*dl_elf_func) ();
 786                 }
 787         }
 788
 789         /* Find the real malloc function and make ldso functions use that from now on */
 790          _dl_malloc_function = (void* (*)(size_t)) (intptr_t) _dl_find_hash("malloc",
 791                          _dl_symbol_tables, NULL, ELF_RTYPE_CLASS_PLT);
 792
 793         /* Notify the debugger that all objects are now mapped in.  */
 794         _dl_debug_addr->r_state = RT_CONSISTENT;
 795         _dl_debug_state();
 796 }
 797
 798 char *_dl_getenv(const char *symbol, char **envp)
 799 {
 800         char *pnt;
 801         const char *pnt1;
 802
 803         while ((pnt = *envp++)) {
 804                 pnt1 = symbol;
 805                 while (*pnt && *pnt == *pnt1)
 806                         pnt1++, pnt++;
 807                 if (!*pnt || *pnt != '=' || *pnt1)
 808                         continue;
 809                 return pnt + 1;
 810         }
 811         return 0;
 812 }
 813
 814 void _dl_unsetenv(const char *symbol, char **envp)
 815 {
 816         char *pnt;
 817         const char *pnt1;
 818         char **newenvp = envp;
 819
 820         for (pnt = *envp; pnt; pnt = *++envp) {
 821                 pnt1 = symbol;
 822                 while (*pnt && *pnt == *pnt1)
 823                         pnt1++, pnt++;
 824                 if (!*pnt || *pnt != '=' || *pnt1)
 825                         *newenvp++ = *envp;
 826         }
 827         *newenvp++ = *envp;
 828         return;
 829 }
 830
 831 static int _dl_suid_ok(void)
 832 {
 833         __kernel_uid_t uid, euid;
 834         __kernel_gid_t gid, egid;
 835
 836         uid = _dl_getuid();
 837         euid = _dl_geteuid();
 838         gid = _dl_getgid();
 839         egid = _dl_getegid();
 840
 841         if(uid == euid && gid == egid) {
 842                 return 1;
 843         }
 844         return 0;
 845 }
 846
 847 void *_dl_malloc(int size)
 848 {
 849         void *retval;
 850
 851 #if 0
 852         _dl_debug_early("request for %d bytes\n", size);
 853 #endif
 854
 855         if (_dl_malloc_function)
 856                 return (*_dl_malloc_function) (size);
 857
 858         if (_dl_malloc_addr - _dl_mmap_zero + (unsigned)size > _dl_pagesize) {
 859                 _dl_debug_early("mmapping more memory\n");
 860                 _dl_mmap_zero = _dl_malloc_addr = _dl_mmap((void *) 0, size,
 861                                 PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 862                 if (_dl_mmap_check_error(_dl_mmap_zero)) {
 863                         _dl_dprintf(_dl_debug_file, "%s: mmap of a spare page failed!\n", _dl_progname);
 864                         _dl_exit(20);
 865                 }
 866         }
 867         retval = _dl_malloc_addr;
 868         _dl_malloc_addr += size;
 869
 870         /*
 871          * Align memory to 4 byte boundary.  Some platforms require this,
 872          * others simply get better performance.
 873          */
 874         _dl_malloc_addr = (unsigned char *) (((unsigned long) _dl_malloc_addr + 3) & ~(3));
 875         return retval;
 876 }
 877
 878 #include "dl-hash.c"
 879 #include "dl-elf.c"