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         = NULL;  /* Where we look for libraries */
  46 char *_dl_preload              = NULL;  /* Things to be loaded before the libs */
  47 char *_dl_ldsopath             = NULL;  /* Location of the shared lib loader */
  48 int _dl_errno                  = 0;     /* We can't use the real errno in ldso */
  49 size_t _dl_pagesize            = 0;     /* Store the page size for use later */
  50 struct r_debug *_dl_debug_addr = NULL;  /* Used to communicate with the gdb debugger */
  51 void *(*_dl_malloc_function) (size_t size) = NULL;
  52 void (*_dl_free_function) (void *p) = NULL;
  53
  54 static int _dl_secure = 1; /* Are we dealing with setuid stuff? */
  55
  56 #ifdef __SUPPORT_LD_DEBUG__
  57 char *_dl_debug           = NULL;
  58 char *_dl_debug_symbols   = NULL;
  59 char *_dl_debug_move      = NULL;
  60 char *_dl_debug_reloc     = NULL;
  61 char *_dl_debug_detail    = NULL;
  62 char *_dl_debug_nofixups  = NULL;
  63 char *_dl_debug_bindings  = NULL;
  64 int   _dl_debug_file      = 2;
  65 #endif
  66
  67 /* Needed for standalone execution. */
  68 unsigned long attribute_hidden _dl_skip_args = 0;
  69 const char *_dl_progname = UCLIBC_LDSO;      /* The name of the executable being run */
  70 #include "dl-startup.c"
  71 #include "dl-symbols.c"
  72 #include "dl-array.c"
  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 = NULL;   /* Lets _dl_malloc use the already allocated memory page */
  91 static unsigned char *_dl_mmap_zero   = NULL;   /* 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 static 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 # endif
 105 # ifdef __UCLIBC_HAS_SSP_COMPAT__
 106 uintptr_t __guard attribute_relro;
 107 # endif
 108 #endif
 109
 110 char *_dl_getenv(const char *symbol, char **envp)
 111 {
 112         char *pnt;
 113         const char *pnt1;
 114
 115         while ((pnt = *envp++)) {
 116                 pnt1 = symbol;
 117                 while (*pnt && *pnt == *pnt1)
 118                         pnt1++, pnt++;
 119                 if (!*pnt || *pnt != '=' || *pnt1)
 120                         continue;
 121                 return pnt + 1;
 122         }
 123         return 0;
 124 }
 125
 126 void _dl_unsetenv(const char *symbol, char **envp)
 127 {
 128         char *pnt;
 129         const char *pnt1;
 130         char **newenvp = envp;
 131
 132         for (pnt = *envp; pnt; pnt = *++envp) {
 133                 pnt1 = symbol;
 134                 while (*pnt && *pnt == *pnt1)
 135                         pnt1++, pnt++;
 136                 if (!*pnt || *pnt != '=' || *pnt1)
 137                         *newenvp++ = *envp;
 138         }
 139         *newenvp++ = *envp;
 140         return;
 141 }
 142
 143 static int _dl_suid_ok(void)
 144 {
 145         __kernel_uid_t uid, euid;
 146         __kernel_gid_t gid, egid;
 147
 148         uid = _dl_getuid();
 149         euid = _dl_geteuid();
 150         gid = _dl_getgid();
 151         egid = _dl_getegid();
 152
 153         if (uid == euid && gid == egid) {
 154                 return 1;
 155         }
 156         return 0;
 157 }
 158
 159 void *_dl_malloc(size_t size)
 160 {
 161         void *retval;
 162
 163 #if 0
 164         _dl_debug_early("request for %d bytes\n", size);
 165 #endif
 166
 167         if (_dl_malloc_function)
 168                 return (*_dl_malloc_function) (size);
 169
 170         if (_dl_malloc_addr - _dl_mmap_zero + size > _dl_pagesize) {
 171                 size_t rounded_size;
 172
 173                 /* Since the above assumes we get a full page even if
 174                    we request less than that, make sure we request a
 175                    full page, since uClinux may give us less than than
 176                    a full page.  We might round even
 177                    larger-than-a-page sizes, but we end up never
 178                    reusing _dl_mmap_zero/_dl_malloc_addr in that case,
 179                    so we don't do it.
 180
 181                    The actual page size doesn't really matter; as long
 182                    as we're self-consistent here, we're safe.  */
 183                 if (size < _dl_pagesize)
 184                         rounded_size = (size + ADDR_ALIGN) & _dl_pagesize;
 185                 else
 186                         rounded_size = size;
 187
 188                 _dl_debug_early("mmapping more memory\n");
 189                 _dl_mmap_zero = _dl_malloc_addr = _dl_mmap((void *) 0, rounded_size,
 190                                 PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
 191                 if (_dl_mmap_check_error(_dl_mmap_zero)) {
 192                         _dl_dprintf(_dl_debug_file, "%s: mmap of a spare page failed!\n", _dl_progname);
 193                         _dl_exit(20);
 194                 }
 195         }
 196         retval = _dl_malloc_addr;
 197         _dl_malloc_addr += size;
 198
 199         /*
 200          * Align memory to DL_MALLOC_ALIGN byte boundary.  Some
 201          * platforms require this, others simply get better
 202          * performance.
 203          */
 204         _dl_malloc_addr = (unsigned char *) (((unsigned long) _dl_malloc_addr + DL_MALLOC_ALIGN - 1) & ~(DL_MALLOC_ALIGN - 1));
 205         return retval;
 206 }
 207
 208 static void *_dl_zalloc(size_t size)
 209 {
 210         void *p = _dl_malloc(size);
 211         if (p)
 212                 _dl_memset(p, 0, size);
 213         return p;
 214 }
 215
 216 void _dl_free (void *p)
 217 {
 218         if (_dl_free_function)
 219                 (*_dl_free_function) (p);
 220 }
 221
 222 static void __attribute__ ((destructor)) __attribute_used__ _dl_fini(void)
 223 {
 224         unsigned int i;
 225         struct elf_resolve * tpnt;
 226
 227         for (i = 0; i < nlist; ++i) {
 228                 tpnt = init_fini_list[i];
 229                 if (tpnt->init_flag & FINI_FUNCS_CALLED)
 230                         continue;
 231                 tpnt->init_flag |= FINI_FUNCS_CALLED;
 232                 _dl_run_fini_array(tpnt);
 233                 if (tpnt->dynamic_info[DT_FINI]) {
 234                         void (*dl_elf_func) (void);
 235
 236                         dl_elf_func = (void (*)(void)) (intptr_t) DL_RELOC_ADDR(tpnt->loadaddr, tpnt->dynamic_info[DT_FINI]);
 237                         _dl_if_debug_dprint("\ncalling FINI: %s\n\n", tpnt->libname);
 238                         DL_CALL_FUNC_AT_ADDR (dl_elf_func, tpnt->loadaddr, (void(*)(void)));
 239                 }
 240         }
 241 }
 242
 243 void _dl_get_ready_to_run(struct elf_resolve *tpnt, DL_LOADADDR_TYPE load_addr,
 244                           ElfW(auxv_t) auxvt[AT_EGID + 1], char **envp,
 245                           char **argv
 246                           DL_GET_READY_TO_RUN_EXTRA_PARMS)
 247 {
 248         ElfW(Addr) app_mapaddr = 0;
 249         ElfW(Phdr) *ppnt;
 250         ElfW(Dyn) *dpnt;
 251         char *lpntstr;
 252         unsigned int i;
 253         int unlazy = 0, trace_loaded_objects = 0;
 254         struct dyn_elf *rpnt;
 255         struct elf_resolve *tcurr;
 256         struct elf_resolve *tpnt1;
 257         struct elf_resolve app_tpnt_tmp;
 258         struct elf_resolve *app_tpnt = &app_tpnt_tmp;
 259         struct r_debug *debug_addr;
 260         unsigned long *lpnt;
 261         unsigned long *_dl_envp;                /* The environment address */
 262         ElfW(Addr) relro_addr = 0;
 263         size_t relro_size = 0;
 264         struct stat st;
 265
 266         /* Wahoo!!! We managed to make a function call!  Get malloc
 267          * setup so we can use _dl_dprintf() to print debug noise
 268          * instead of the SEND_STDERR macros used in dl-startup.c */
 269
 270         _dl_memset(app_tpnt, 0, sizeof(*app_tpnt));
 271
 272         /* Store the page size for later use */
 273         _dl_pagesize = (auxvt[AT_PAGESZ].a_un.a_val) ? (size_t) auxvt[AT_PAGESZ].a_un.a_val : PAGE_SIZE;
 274         /* Make it so _dl_malloc can use the page of memory we have already
 275          * allocated.  We shouldn't need to grab any more memory.  This must
 276          * be first since things like _dl_dprintf() use _dl_malloc()...
 277          */
 278         _dl_malloc_addr = (unsigned char *)_dl_pagesize;
 279         _dl_mmap_zero = 0;
 280
 281         /* Wahoo!!! */
 282         _dl_debug_early("Cool, ldso survived making function calls\n");
 283
 284         /* Now we have done the mandatory linking of some things.  We are now
 285          * free to start using global variables, since these things have all
 286          * been fixed up by now.  Still no function calls outside of this
 287          * library, since the dynamic resolver is not yet ready.
 288          */
 289         if (argv[0]) {
 290                 _dl_progname = argv[0];
 291         }
 292
 293         if (_start == (void *) auxvt[AT_ENTRY].a_un.a_val) {
 294                 _dl_dprintf(_dl_debug_file, "Standalone execution is not supported yet\n");
 295                 _dl_exit(1);
 296         }
 297
 298         /* Start to build the tables of the modules that are required for
 299          * this beast to run.  We start with the basic executable, and then
 300          * go from there.  Eventually we will run across ourself, and we
 301          * will need to properly deal with that as well.
 302          */
 303         rpnt = NULL;
 304         if (_dl_getenv("LD_BIND_NOW", envp))
 305                 unlazy = RTLD_NOW;
 306
 307         /* Now we need to figure out what kind of options are selected.
 308          * Note that for SUID programs we ignore the settings in
 309          * LD_LIBRARY_PATH.
 310          */
 311         if ((auxvt[AT_UID].a_un.a_val == (size_t)-1 && _dl_suid_ok()) ||
 312             (auxvt[AT_UID].a_un.a_val != (size_t)-1 &&
 313              auxvt[AT_UID].a_un.a_val == auxvt[AT_EUID].a_un.a_val &&
 314              auxvt[AT_GID].a_un.a_val == auxvt[AT_EGID].a_un.a_val)) {
 315                 _dl_secure = 0;
 316                 _dl_preload = _dl_getenv("LD_PRELOAD", envp);
 317                 _dl_library_path = _dl_getenv("LD_LIBRARY_PATH", envp);
 318         } else {
 319                 static const char unsecure_envvars[] =
 320 #ifdef EXTRA_UNSECURE_ENVVARS
 321                         EXTRA_UNSECURE_ENVVARS
 322 #endif
 323                         UNSECURE_ENVVARS;
 324                 const char *nextp;
 325                 _dl_secure = 1;
 326
 327                 nextp = unsecure_envvars;
 328                 do {
 329                         _dl_unsetenv (nextp, envp);
 330                         /* We could use rawmemchr but this need not be fast.  */
 331                         nextp = _dl_strchr(nextp, '\0') + 1;
 332                 } while (*nextp != '\0');
 333                 _dl_preload = NULL;
 334                 _dl_library_path = NULL;
 335                 /* SUID binaries can be exploited if they do LAZY relocation. */
 336                 unlazy = RTLD_NOW;
 337         }
 338
 339         /* sjhill: your TLS init should go before this */
 340 #ifdef __UCLIBC_HAS_SSP__
 341         /* Set up the stack checker's canary.  */
 342         stack_chk_guard = _dl_setup_stack_chk_guard ();
 343 # ifdef THREAD_SET_STACK_GUARD
 344         THREAD_SET_STACK_GUARD (stack_chk_guard);
 345 # else
 346         __stack_chk_guard = stack_chk_guard;
 347 # endif
 348 # ifdef __UCLIBC_HAS_SSP_COMPAT__
 349         __guard = stack_chk_guard;
 350 # endif
 351 #endif
 352
 353         /* At this point we are now free to examine the user application,
 354          * and figure out which libraries are supposed to be called.  Until
 355          * we have this list, we will not be completely ready for dynamic
 356          * linking.
 357          */
 358
 359         /* Find the runtime load address of the main executable.  This may be
 360          * different from what the ELF header says for ET_DYN/PIE executables.
 361          */
 362         {
 363                 unsigned int idx;
 364                 ElfW(Phdr) *phdr = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
 365
 366                 for (idx = 0; idx < auxvt[AT_PHNUM].a_un.a_val; idx++, phdr++)
 367                         if (phdr->p_type == PT_PHDR) {
 368                                 DL_INIT_LOADADDR_PROG(app_tpnt->loadaddr, auxvt[AT_PHDR].a_un.a_val - phdr->p_vaddr);
 369                                 break;
 370                         }
 371
 372                 if (DL_LOADADDR_BASE(app_tpnt->loadaddr))
 373                         _dl_debug_early("Position Independent Executable: "
 374                                         "app_tpnt->loadaddr=%x\n", DL_LOADADDR_BASE(app_tpnt->loadaddr));
 375         }
 376
 377         /*
 378          * This is used by gdb to locate the chain of shared libraries that are
 379          * currently loaded.
 380          */
 381         debug_addr = _dl_zalloc(sizeof(struct r_debug));
 382
 383         ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
 384         for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++) {
 385                 if (ppnt->p_type == PT_GNU_RELRO) {
 386                         relro_addr = ppnt->p_vaddr;
 387                         relro_size = ppnt->p_memsz;
 388                 }
 389                 if (!app_mapaddr && (ppnt->p_type == PT_LOAD)) {
 390                         app_mapaddr = DL_RELOC_ADDR (app_tpnt->loadaddr, ppnt->p_vaddr);
 391                 }
 392                 if (ppnt->p_type == PT_DYNAMIC) {
 393                         dpnt = (ElfW(Dyn) *) DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr);
 394                         _dl_parse_dynamic_info(dpnt, app_tpnt->dynamic_info, debug_addr, app_tpnt->loadaddr);
 395 #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
 396                         /* Ugly, ugly.  We need to call mprotect to change the
 397                          * protection of the text pages so that we can do the
 398                          * dynamic linking.  We can set the protection back
 399                          * again once we are done.
 400                          */
 401                         _dl_debug_early("calling mprotect on the application program\n");
 402                         /* Now cover the application program. */
 403                         if (app_tpnt->dynamic_info[DT_TEXTREL]) {
 404                                 ElfW(Phdr) *ppnt_outer = ppnt;
 405                                 ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
 406                                 for (i = 0; i < auxvt[AT_PHNUM].a_un.a_val; i++, ppnt++) {
 407                                         if (ppnt->p_type == PT_LOAD && !(ppnt->p_flags & PF_W))
 408                                                 _dl_mprotect((void *) (DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr) & PAGE_ALIGN),
 409                                                              ((ppnt->p_vaddr + app_tpnt->loadaddr) & ADDR_ALIGN) +
 410                                                              (unsigned long) ppnt->p_filesz,
 411                                                              PROT_READ | PROT_WRITE | PROT_EXEC);
 412                                 }
 413                                 ppnt = ppnt_outer;
 414                         }
 415 #else
 416                         if (app_tpnt->dynamic_info[DT_TEXTREL]) {
 417                                 _dl_dprintf(_dl_debug_file, "Can't modify application's text section; use the GCC option -fPIE for position-independent executables.\n");
 418                                 _dl_exit(1);
 419                         }
 420 #endif
 421
 422 #ifndef ALLOW_ZERO_PLTGOT
 423                         /* make sure it's really there. */
 424                         if (app_tpnt->dynamic_info[DT_PLTGOT] == 0)
 425                                 continue;
 426 #endif
 427                         /* OK, we have what we need - slip this one into the list. */
 428                         app_tpnt = _dl_add_elf_hash_table(_dl_progname, app_tpnt->loadaddr,
 429                                         app_tpnt->dynamic_info,
 430                                         (unsigned long) DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr),
 431                                         ppnt->p_filesz);
 432                         _dl_loaded_modules->libtype = elf_executable;
 433                         _dl_loaded_modules->ppnt = (ElfW(Phdr) *) auxvt[AT_PHDR].a_un.a_val;
 434                         _dl_loaded_modules->n_phent = auxvt[AT_PHNUM].a_un.a_val;
 435                         _dl_symbol_tables = rpnt = _dl_zalloc(sizeof(struct dyn_elf));
 436                         rpnt->dyn = _dl_loaded_modules;
 437                         app_tpnt->mapaddr = app_mapaddr;
 438                         app_tpnt->rtld_flags = unlazy | RTLD_GLOBAL;
 439                         app_tpnt->usage_count++;
 440                         app_tpnt->symbol_scope = _dl_symbol_tables;
 441                         lpnt = (unsigned long *) (app_tpnt->dynamic_info[DT_PLTGOT]);
 442 #ifdef ALLOW_ZERO_PLTGOT
 443                         if (lpnt)
 444 #endif
 445                                 INIT_GOT(lpnt, _dl_loaded_modules);
 446                 }
 447
 448                 /* OK, fill this in - we did not have this before */
 449                 if (ppnt->p_type == PT_INTERP) {
 450                         char *ptmp;
 451
 452                         tpnt->libname = (char *) DL_RELOC_ADDR(app_tpnt->loadaddr, ppnt->p_vaddr);
 453
 454                         /* Store the path where the shared lib loader was found
 455                          * for later use
 456                          */
 457                         _dl_ldsopath = _dl_strdup(tpnt->libname);
 458                         ptmp = _dl_strrchr(_dl_ldsopath, '/');
 459                         if (ptmp != _dl_ldsopath)
 460                                 *ptmp = '\0';
 461
 462                         _dl_debug_early("Lib Loader: (%x) %s\n", (unsigned) DL_LOADADDR_BASE(tpnt->loadaddr), tpnt->libname);
 463                 }
 464         }
 465         app_tpnt->relro_addr = relro_addr;
 466         app_tpnt->relro_size = relro_size;
 467
 468 #ifdef __SUPPORT_LD_DEBUG__
 469         _dl_debug = _dl_getenv("LD_DEBUG", envp);
 470         if (_dl_debug) {
 471                 if (_dl_strstr(_dl_debug, "all")) {
 472                         _dl_debug_detail = _dl_debug_move = _dl_debug_symbols
 473                                 = _dl_debug_reloc = _dl_debug_bindings = _dl_debug_nofixups = (void*)1;
 474                 } else {
 475                         _dl_debug_detail   = _dl_strstr(_dl_debug, "detail");
 476                         _dl_debug_move     = _dl_strstr(_dl_debug, "move");
 477                         _dl_debug_symbols  = _dl_strstr(_dl_debug, "sym");
 478                         _dl_debug_reloc    = _dl_strstr(_dl_debug, "reloc");
 479                         _dl_debug_nofixups = _dl_strstr(_dl_debug, "nofix");
 480                         _dl_debug_bindings = _dl_strstr(_dl_debug, "bind");
 481                 }
 482         }
 483
 484         {
 485                 const char *dl_debug_output;
 486
 487                 dl_debug_output = _dl_getenv("LD_DEBUG_OUTPUT", envp);
 488
 489                 if (dl_debug_output) {
 490                         char tmp[22], *tmp1, *filename;
 491                         int len1, len2;
 492
 493                         _dl_memset(tmp, 0, sizeof(tmp));
 494                         tmp1 = _dl_simple_ltoa( tmp, (unsigned long)_dl_getpid());
 495
 496                         len1 = _dl_strlen(dl_debug_output);
 497                         len2 = _dl_strlen(tmp1);
 498
 499                         filename = _dl_malloc(len1 + len2 + 2);
 500
 501                         if (filename) {
 502                                 _dl_strcpy (filename, dl_debug_output);
 503                                 filename[len1] = '.';
 504                                 _dl_strcpy (&filename[len1+1], tmp1);
 505
 506                                 _dl_debug_file = _dl_open(filename, O_WRONLY|O_CREAT, 0644);
 507                                 if (_dl_debug_file < 0) {
 508                                         _dl_debug_file = 2;
 509                                         _dl_dprintf(_dl_debug_file, "can't open file: '%s'\n",filename);
 510                                 }
 511                         }
 512                 }
 513         }
 514 #endif
 515
 516         if (_dl_getenv("LD_TRACE_LOADED_OBJECTS", envp) != NULL) {
 517                 trace_loaded_objects++;
 518         }
 519
 520 #ifndef __LDSO_LDD_SUPPORT__
 521         if (trace_loaded_objects) {
 522                 _dl_dprintf(_dl_debug_file, "Use the ldd provided by uClibc\n");
 523                 _dl_exit(1);
 524         }
 525 #endif
 526
 527         /*
 528          * OK, fix one more thing - set up debug_addr so it will point
 529          * to our chain.  Later we may need to fill in more fields, but this
 530          * should be enough for now.
 531          */
 532         debug_addr->r_map = (struct link_map *) _dl_loaded_modules;
 533         debug_addr->r_version = 1;
 534         debug_addr->r_ldbase = DL_LOADADDR_BASE(load_addr);
 535         debug_addr->r_brk = (unsigned long) &_dl_debug_state;
 536         _dl_debug_addr = debug_addr;
 537
 538         /* Do not notify the debugger until the interpreter is in the list */
 539
 540         /* OK, we now have the application in the list, and we have some
 541          * basic stuff in place.  Now search through the list for other shared
 542          * libraries that should be loaded, and insert them on the list in the
 543          * correct order.
 544          */
 545
 546         _dl_map_cache();
 547
 548         if (_dl_preload) {
 549                 char c, *str, *str2;
 550
 551                 str = _dl_preload;
 552                 while (*str == ':' || *str == ' ' || *str == '\t')
 553                         str++;
 554
 555                 while (*str) {
 556                         str2 = str;
 557                         while (*str2 && *str2 != ':' && *str2 != ' ' && *str2 != '\t')
 558                                 str2++;
 559                         c = *str2;
 560                         *str2 = '\0';
 561
 562                         if (!_dl_secure || _dl_strchr(str, '/') == NULL) {
 563                                 _dl_if_debug_dprint("\tfile='%s';  needed by '%s'\n", str, _dl_progname);
 564
 565                                 tpnt1 = _dl_load_shared_library(_dl_secure, &rpnt, NULL, str, trace_loaded_objects);
 566                                 if (!tpnt1) {
 567 #ifdef __LDSO_LDD_SUPPORT__
 568                                         if (trace_loaded_objects)
 569                                                 _dl_dprintf(1, "\t%s => not found\n", str);
 570                                         else
 571 #endif
 572                                         {
 573                                                 _dl_dprintf(_dl_debug_file, "%s: can't load " "library '%s'\n", _dl_progname, str);
 574                                                 _dl_exit(15);
 575                                         }
 576                                 } else {
 577                                         tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
 578
 579                                         _dl_debug_early("Loading: (%x) %s\n", DL_LOADADDR_BASE(tpnt1->loadaddr), tpnt1->libname);
 580
 581 #ifdef __LDSO_LDD_SUPPORT__
 582                                         if (trace_loaded_objects &&
 583                                             tpnt1->usage_count == 1) {
 584                                                 /* This is a real hack to make
 585                                                  * ldd not print the library
 586                                                  * itself when run on a
 587                                                  * library.
 588                                                  */
 589                                                 if (_dl_strcmp(_dl_progname, str) != 0)
 590                                                         _dl_dprintf(1, "\t%s => %s (%x)\n", str, tpnt1->libname,
 591                                                                     DL_LOADADDR_BASE(tpnt1->loadaddr));
 592                                         }
 593 #endif
 594                                 }
 595                         }
 596
 597                         *str2 = c;
 598                         str = str2;
 599                         while (*str == ':' || *str == ' ' || *str == '\t')
 600                                 str++;
 601                 }
 602         }
 603
 604 #ifdef __LDSO_PRELOAD_FILE_SUPPORT__
 605         do {
 606                 char *preload;
 607                 int fd;
 608                 char c, *cp, *cp2;
 609
 610                 if (_dl_stat(LDSO_PRELOAD, &st) || st.st_size == 0) {
 611                         break;
 612                 }
 613
 614                 if ((fd = _dl_open(LDSO_PRELOAD, O_RDONLY, 0)) < 0) {
 615                         _dl_dprintf(_dl_debug_file, "%s: can't open file '%s'\n",
 616                                     _dl_progname, LDSO_PRELOAD);
 617                         break;
 618                 }
 619
 620                 preload = (caddr_t) _dl_mmap(0, st.st_size + 1,
 621                                              PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
 622                 _dl_close(fd);
 623                 if (preload == (caddr_t) -1) {
 624                         _dl_dprintf(_dl_debug_file, "%s:%i: can't map '%s'\n",
 625                                     _dl_progname, __LINE__, LDSO_PRELOAD);
 626                         break;
 627                 }
 628
 629                 /* convert all separators and comments to spaces */
 630                 for (cp = preload; *cp; /*nada */ ) {
 631                         if (*cp == ':' || *cp == '\t' || *cp == '\n') {
 632                                 *cp++ = ' ';
 633                         } else if (*cp == '#') {
 634                                 do {
 635                                         *cp++ = ' ';
 636                                 } while (*cp != '\n' && *cp != '\0');
 637                         } else {
 638                                 cp++;
 639                         }
 640                 }
 641
 642                 /* find start of first library */
 643                 for (cp = preload; *cp && *cp == ' '; cp++)
 644                         /*nada */ ;
 645
 646                 while (*cp) {
 647                         /* find end of library */
 648                         for (cp2 = cp; *cp && *cp != ' '; cp++)
 649                                 /*nada */ ;
 650                         c = *cp;
 651                         *cp = '\0';
 652
 653                         _dl_if_debug_dprint("\tfile='%s';  needed by '%s'\n", cp2, _dl_progname);
 654
 655                         tpnt1 = _dl_load_shared_library(0, &rpnt, NULL, cp2, trace_loaded_objects);
 656                         if (!tpnt1) {
 657 #ifdef __LDSO_LDD_SUPPORT__
 658                                 if (trace_loaded_objects)
 659                                         _dl_dprintf(1, "\t%s => not found\n", cp2);
 660                                 else
 661 #endif
 662                                 {
 663                                         _dl_dprintf(_dl_debug_file, "%s: can't load library '%s'\n", _dl_progname, cp2);
 664                                         _dl_exit(15);
 665                                 }
 666                         } else {
 667                                 tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
 668
 669                                 _dl_debug_early("Loading: (%x) %s\n", DL_LOADADDR_BASE(tpnt1->loadaddr), tpnt1->libname);
 670
 671 #ifdef __LDSO_LDD_SUPPORT__
 672                                 if (trace_loaded_objects &&
 673                                     tpnt1->usage_count == 1) {
 674                                         _dl_dprintf(1, "\t%s => %s (%x)\n",
 675                                                     cp2, tpnt1->libname,
 676                                                     DL_LOADADDR_BASE(tpnt1->loadaddr));
 677                                 }
 678 #endif
 679                         }
 680
 681                         /* find start of next library */
 682                         *cp = c;
 683                         for ( /*nada */ ; *cp && *cp == ' '; cp++)
 684                                 /*nada */ ;
 685                 }
 686
 687                 _dl_munmap(preload, st.st_size + 1);
 688         } while (0);
 689 #endif /* __LDSO_PRELOAD_FILE_SUPPORT__ */
 690
 691         nlist = 0;
 692         for (tcurr = _dl_loaded_modules; tcurr; tcurr = tcurr->next) {
 693                 ElfW(Dyn) *this_dpnt;
 694
 695                 nlist++;
 696                 for (this_dpnt = (ElfW(Dyn) *) tcurr->dynamic_addr; this_dpnt->d_tag; this_dpnt++) {
 697                         if (this_dpnt->d_tag == DT_NEEDED) {
 698                                 char *name;
 699                                 struct init_fini_list *tmp;
 700
 701                                 lpntstr = (char*) (tcurr->dynamic_info[DT_STRTAB] + this_dpnt->d_un.d_val);
 702                                 name = _dl_get_last_path_component(lpntstr);
 703                                 if (_dl_strcmp(name, UCLIBC_LDSO) == 0)
 704                                         continue;
 705
 706                                 _dl_if_debug_dprint("\tfile='%s';  needed by '%s'\n", lpntstr, _dl_progname);
 707
 708                                 if (!(tpnt1 = _dl_load_shared_library(0, &rpnt, tcurr, lpntstr, trace_loaded_objects))) {
 709 #ifdef __LDSO_LDD_SUPPORT__
 710                                         if (trace_loaded_objects) {
 711                                                 _dl_dprintf(1, "\t%s => not found\n", lpntstr);
 712                                                 continue;
 713                                         } else
 714 #endif
 715                                         {
 716                                                 _dl_dprintf(_dl_debug_file, "%s: can't load library '%s'\n", _dl_progname, lpntstr);
 717                                                 _dl_exit(16);
 718                                         }
 719                                 }
 720
 721                                 tmp = alloca(sizeof(struct init_fini_list)); /* Allocates on stack, no need to free this memory */
 722                                 tmp->tpnt = tpnt1;
 723                                 tmp->next = tcurr->init_fini;
 724                                 tcurr->init_fini = tmp;
 725
 726                                 tpnt1->rtld_flags = unlazy | RTLD_GLOBAL;
 727
 728                                 _dl_debug_early("Loading: (%x) %s\n", DL_LOADADDR_BASE(tpnt1->loadaddr), tpnt1->libname);
 729
 730 #ifdef __LDSO_LDD_SUPPORT__
 731                                 if (trace_loaded_objects &&
 732                                     tpnt1->usage_count == 1) {
 733                                         _dl_dprintf(1, "\t%s => %s (%x)\n",
 734                                                     lpntstr, tpnt1->libname,
 735                                                     DL_LOADADDR_BASE(tpnt1->loadaddr));
 736                                 }
 737 #endif
 738                         }
 739                 }
 740         }
 741         _dl_unmap_cache();
 742
 743         --nlist; /* Exclude the application. */
 744         init_fini_list = _dl_malloc(nlist * sizeof(struct elf_resolve *));
 745         i = 0;
 746         for (tcurr = _dl_loaded_modules->next; tcurr; tcurr = tcurr->next) {
 747                 init_fini_list[i++] = tcurr;
 748         }
 749
 750         /* Sort the INIT/FINI list in dependency order. */
 751         for (tcurr = _dl_loaded_modules->next; tcurr; tcurr = tcurr->next) {
 752                 unsigned int j, k;
 753
 754                 for (j = 0; init_fini_list[j] != tcurr; ++j)
 755                         /* Empty */;
 756                 for (k = j + 1; k < nlist; ++k) {
 757                         struct init_fini_list *runp = init_fini_list[k]->init_fini;
 758
 759                         for (; runp; runp = runp->next) {
 760                                 if (runp->tpnt == tcurr) {
 761                                         struct elf_resolve *here = init_fini_list[k];
 762                                         _dl_if_debug_dprint("Move %s from pos %d to %d in INIT/FINI list\n", here->libname, k, j);
 763                                         for (i = (k - j); i; --i)
 764                                                 init_fini_list[i+j] = init_fini_list[i+j-1];
 765                                         init_fini_list[j] = here;
 766                                         ++j;
 767                                         break;
 768                                 }
 769                         }
 770                 }
 771         }
 772 #ifdef __SUPPORT_LD_DEBUG__
 773         if (_dl_debug) {
 774                 _dl_dprintf(_dl_debug_file, "\nINIT/FINI order and dependencies:\n");
 775                 for (i = 0; i < nlist; i++) {
 776                         struct init_fini_list *tmp;
 777
 778                         _dl_dprintf(_dl_debug_file, "lib: %s has deps:\n",
 779                                     init_fini_list[i]->libname);
 780                         tmp = init_fini_list[i]->init_fini;
 781                         for (; tmp; tmp = tmp->next)
 782                                 _dl_dprintf(_dl_debug_file, " %s ", tmp->tpnt->libname);
 783                         _dl_dprintf(_dl_debug_file, "\n");
 784                 }
 785         }
 786 #endif
 787
 788         /*
 789          * If the program interpreter is not in the module chain, add it.
 790          * This will be required for dlopen to be able to access the internal
 791          * functions in the dynamic linker and to relocate the interpreter
 792          * again once all libs are loaded.
 793          */
 794         if (tpnt) {
 795                 ElfW(Ehdr) *epnt = (ElfW(Ehdr) *) auxvt[AT_BASE].a_un.a_val;
 796                 ElfW(Phdr) *myppnt = (ElfW(Phdr) *) DL_RELOC_ADDR(load_addr, epnt->e_phoff);
 797                 int j;
 798
 799                 tpnt = _dl_add_elf_hash_table(tpnt->libname, load_addr,
 800                                               tpnt->dynamic_info,
 801                                               (unsigned long)tpnt->dynamic_addr,
 802                                               0);
 803
 804                 if (_dl_stat(tpnt->libname, &st) >= 0) {
 805                         tpnt->st_dev = st.st_dev;
 806                         tpnt->st_ino = st.st_ino;
 807                 }
 808                 tpnt->n_phent = epnt->e_phnum;
 809                 tpnt->ppnt = myppnt;
 810                 for (j = 0; j < epnt->e_phnum; j++, myppnt++) {
 811                         if (myppnt->p_type ==  PT_GNU_RELRO) {
 812                                 tpnt->relro_addr = myppnt->p_vaddr;
 813                                 tpnt->relro_size = myppnt->p_memsz;
 814                                 break;
 815                         }
 816                 }
 817                 tpnt->libtype = program_interpreter;
 818                 tpnt->usage_count++;
 819                 tpnt->symbol_scope = _dl_symbol_tables;
 820                 if (rpnt) {
 821                         rpnt->next = _dl_zalloc(sizeof(struct dyn_elf));
 822                         rpnt->next->prev = rpnt;
 823                         rpnt = rpnt->next;
 824                 } else {
 825                         rpnt = _dl_zalloc(sizeof(struct dyn_elf));
 826                 }
 827                 rpnt->dyn = tpnt;
 828                 tpnt->rtld_flags = RTLD_NOW | RTLD_GLOBAL; /* Must not be LAZY */
 829 #ifdef RERELOCATE_LDSO
 830                 /* Only rerelocate functions for now. */
 831                 tpnt->init_flag = RELOCS_DONE;
 832                 lpnt = (unsigned long *) (tpnt->dynamic_info[DT_PLTGOT]);
 833 # ifdef ALLOW_ZERO_PLTGOT
 834                 if (tpnt->dynamic_info[DT_PLTGOT])
 835 # endif
 836                         INIT_GOT(lpnt, tpnt);
 837 #else
 838                 tpnt->init_flag = RELOCS_DONE | JMP_RELOCS_DONE;
 839 #endif
 840                 tpnt = NULL;
 841         }
 842
 843 #ifdef __LDSO_LDD_SUPPORT__
 844         /* End of the line for ldd.... */
 845         if (trace_loaded_objects) {
 846                 _dl_dprintf(1, "\t%s => %s (%x)\n",
 847                             rpnt->dyn->libname + _dl_strlen(_dl_ldsopath) + 1,
 848                             rpnt->dyn->libname, DL_LOADADDR_BASE(rpnt->dyn->loadaddr));
 849                 _dl_exit(0);
 850         }
 851 #endif
 852
 853         _dl_debug_early("Beginning relocation fixups\n");
 854
 855 #ifdef __mips__
 856         /*
 857          * Relocation of the GOT entries for MIPS have to be done
 858          * after all the libraries have been loaded.
 859          */
 860         _dl_perform_mips_global_got_relocations(_dl_loaded_modules, !unlazy);
 861 #endif
 862
 863         /*
 864          * OK, now all of the kids are tucked into bed in their proper
 865          * addresses.  Now we go through and look for REL and RELA records that
 866          * indicate fixups to the GOT tables.  We need to do this in reverse
 867          * order so that COPY directives work correctly.
 868          */
 869         if (_dl_symbol_tables)
 870                 if (_dl_fixup(_dl_symbol_tables, unlazy))
 871                         _dl_exit(-1);
 872
 873         for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
 874                 if (tpnt->relro_size)
 875                         _dl_protect_relro (tpnt);
 876         }
 877
 878         /* OK, at this point things are pretty much ready to run.  Now we need
 879          * to touch up a few items that are required, and then we can let the
 880          * user application have at it.  Note that the dynamic linker itself
 881          * is not guaranteed to be fully dynamicly linked if we are using
 882          * ld.so.1, so we have to look up each symbol individually.
 883          */
 884
 885         _dl_envp = (unsigned long *) (intptr_t) _dl_find_hash(__C_SYMBOL_PREFIX__ "__environ", _dl_symbol_tables, NULL, 0);
 886         if (_dl_envp)
 887                 *_dl_envp = (unsigned long) envp;
 888
 889 #ifndef __FORCE_SHAREABLE_TEXT_SEGMENTS__
 890         {
 891                 unsigned int j;
 892                 ElfW(Phdr) *myppnt;
 893
 894                 /* We had to set the protections of all pages to R/W for
 895                  * dynamic linking.  Set text pages back to R/O.
 896                  */
 897                 for (tpnt = _dl_loaded_modules; tpnt; tpnt = tpnt->next) {
 898                         for (myppnt = tpnt->ppnt, j = 0; j < tpnt->n_phent; j++, myppnt++) {
 899                                 if (myppnt->p_type == PT_LOAD && !(myppnt->p_flags & PF_W) && tpnt->dynamic_info[DT_TEXTREL]) {
 900                                         _dl_mprotect((void *) (DL_RELOC_ADDR(tpnt->loadaddr, myppnt->p_vaddr) & PAGE_ALIGN),
 901                                                         (myppnt->p_vaddr & ADDR_ALIGN) + (unsigned long) myppnt->p_filesz, LXFLAGS(myppnt->p_flags));
 902                                 }
 903                         }
 904                 }
 905
 906         }
 907 #endif
 908         /* Notify the debugger we have added some objects. */
 909         _dl_debug_addr->r_state = RT_ADD;
 910         _dl_debug_state();
 911
 912         /* Run pre-initialization functions for the executable.  */
 913         _dl_run_array_forward(_dl_loaded_modules->dynamic_info[DT_PREINIT_ARRAY],
 914                               _dl_loaded_modules->dynamic_info[DT_PREINIT_ARRAYSZ],
 915                               _dl_loaded_modules->loadaddr);
 916
 917         /* Run initialization functions for loaded objects.  For the
 918            main executable, they will be run from __uClibc_main.  */
 919         for (i = nlist; i; --i) {
 920                 tpnt = init_fini_list[i-1];
 921                 tpnt->init_fini = NULL; /* Clear, since alloca was used */
 922                 if (tpnt->init_flag & INIT_FUNCS_CALLED)
 923                         continue;
 924                 tpnt->init_flag |= INIT_FUNCS_CALLED;
 925
 926                 if (tpnt->dynamic_info[DT_INIT]) {
 927                         void (*dl_elf_func) (void);
 928
 929                         dl_elf_func = (void (*)(void)) DL_RELOC_ADDR(tpnt->loadaddr, tpnt->dynamic_info[DT_INIT]);
 930
 931                         _dl_if_debug_dprint("calling INIT: %s\n\n", tpnt->libname);
 932
 933                         DL_CALL_FUNC_AT_ADDR (dl_elf_func, tpnt->loadaddr, (void(*)(void)));
 934                 }
 935
 936                 _dl_run_init_array(tpnt);
 937         }
 938
 939         /* Find the real malloc function and make ldso functions use that from now on */
 940         _dl_malloc_function = (void* (*)(size_t)) (intptr_t) _dl_find_hash(__C_SYMBOL_PREFIX__ "malloc",
 941                         _dl_symbol_tables, NULL, ELF_RTYPE_CLASS_PLT);
 942
 943         /* Notify the debugger that all objects are now mapped in.  */
 944         _dl_debug_addr->r_state = RT_CONSISTENT;
 945         _dl_debug_state();
 946 }
 947
 948 #include "dl-hash.c"
 949 #include "dl-elf.c"