sysdeps/generic/libc-start.c

   1 /* Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Library General Public License as
   6    published by the Free Software Foundation; either version 2 of the
   7    License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Library General Public License for more details.
  13
  14    You should have received a copy of the GNU Library General Public
  15    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  16    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17    Boston, MA 02111-1307, USA.  */
  18
  19 #include <stdlib.h>
  20 #include <unistd.h>
  21 #include <ldsodefs.h>
  22 #include <bp-start.h>
  23 #include <bp-sym.h>
  24
  25 extern void __libc_init_first (int argc, char **argv, char **envp);
  26
  27 extern int _dl_starting_up;
  28 weak_extern (_dl_starting_up)
  29 extern int __libc_multiple_libcs;
  30 extern void *__libc_stack_end;
  31
  32 #ifndef SHARED
  33 extern void __pthread_initialize_minimal (void) __attribute__ ((weak));
  34 #endif
  35
  36
  37 extern int BP_SYM (__libc_start_main) (int (*main) (int, char **, char **),
  38                                        int argc,
  39                                        char *__unbounded *__unbounded ubp_av,
  40                                        void (*init) (void),
  41                                        void (*fini) (void),
  42                                        void (*rtld_fini) (void),
  43                                        void *__unbounded stack_end)
  44      __attribute__ ((noreturn));
  45
  46 int
  47 /* GKM FIXME: GCC: this should get __BP_ prefix by virtue of the
  48    BPs in the arglist of startup_info.main and startup_info.init. */
  49 BP_SYM (__libc_start_main) (int (*main) (int, char **, char **),
  50                    int argc, char *__unbounded *__unbounded ubp_av,
  51                    void (*init) (void), void (*fini) (void),
  52                    void (*rtld_fini) (void), void *__unbounded stack_end)
  53 {
  54   char *__unbounded *__unbounded ubp_ev = &ubp_av[argc + 1];
  55 #if __BOUNDED_POINTERS__
  56   char **argv;
  57 #else
  58 # define argv ubp_av
  59 #endif
  60
  61 #ifndef SHARED
  62 # ifdef HAVE_AUX_VECTOR
  63   void *__unbounded *__unbounded auxvec;
  64 # endif
  65
  66   /* The next variable is only here to work around a bug in gcc <= 2.7.2.2.
  67      If the address would be taken inside the expression the optimizer
  68      would try to be too smart and throws it away.  Grrr.  */
  69   int *dummy_addr = &_dl_starting_up;
  70
  71   __libc_multiple_libcs = dummy_addr && !_dl_starting_up;
  72 #endif
  73
  74   INIT_ARGV_and_ENVIRON;
  75
  76   /* Store the lowest stack address.  */
  77   __libc_stack_end = stack_end;
  78
  79 #ifndef SHARED
  80   /* Initialize the thread library at least a bit since the libgcc
  81      functions are using thread functions if these are available and
  82      we need to setup errno.  */
  83   if (__pthread_initialize_minimal)
  84     __pthread_initialize_minimal ();
  85
  86   /* Some security at this point.  Prevent starting a SUID binary where
  87      the standard file descriptors are not opened.  We have to do this
  88      only for statically linked applications since otherwise the dynamic
  89      loader did the work already.  */
  90   if (__builtin_expect (__libc_enable_secure, 0))
  91     __libc_check_standard_fds ();
  92
  93 # ifdef HAVE_AUX_VECTOR
  94   for (auxvec = (void *__unbounded *__unbounded) ubp_ev;
  95        *auxvec != NULL; ++auxvec);
  96   ++auxvec;
  97   _dl_aux_init ((ElfW(auxv_t) *) auxvec);
  98 # endif
  99 #endif
 100
 101   /* Register the destructor of the dynamic linker if there is any.  */
 102   if (__builtin_expect (rtld_fini != NULL, 1))
 103     __cxa_atexit ((void (*) (void *)) rtld_fini, NULL, NULL);
 104
 105   /* Call the initializer of the libc.  This is only needed here if we
 106      are compiling for the static library in which case we haven't
 107      run the constructors in `_dl_start_user'.  */
 108 #ifndef SHARED
 109   __libc_init_first (argc, argv, __environ);
 110 #endif
 111
 112   /* Register the destructor of the program, if any.  */
 113   if (fini)
 114     __cxa_atexit ((void (*) (void *)) fini, NULL, NULL);
 115
 116   /* Call the initializer of the program, if any.  */
 117 #ifdef SHARED
 118   if (__builtin_expect (_dl_debug_mask & DL_DEBUG_IMPCALLS, 0))
 119     _dl_debug_printf ("\ninitialize program: %s\n\n", argv[0]);
 120 #endif
 121   if (init)
 122     (*init) ();
 123
 124 #ifdef SHARED
 125   if (__builtin_expect (_dl_debug_mask & DL_DEBUG_IMPCALLS, 0))
 126     _dl_debug_printf ("\ntransferring control: %s\n\n", argv[0]);
 127 #endif
 128
 129   exit ((*main) (argc, argv, __environ));
 130 }