sysdeps/generic/libc-start.c

   1 /* Copyright (C) 1998, 1999, 2000, 2001, 2002 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 Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the 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    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    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 # include <tls.h>
  34 extern void __pthread_initialize_minimal (void)
  35 # if !(USE_TLS - 0)
  36      __attribute__ ((weak))
  37 # endif
  38      ;
  39 #endif
  40
  41
  42 extern int BP_SYM (__libc_start_main) (int (*main) (int, char **, char **),
  43                                        int argc,
  44                                        char *__unbounded *__unbounded ubp_av,
  45                                        void (*init) (void),
  46                                        void (*fini) (void),
  47                                        void (*rtld_fini) (void),
  48                                        void *__unbounded stack_end)
  49      __attribute__ ((noreturn));
  50
  51 int
  52 /* GKM FIXME: GCC: this should get __BP_ prefix by virtue of the
  53    BPs in the arglist of startup_info.main and startup_info.init. */
  54 BP_SYM (__libc_start_main) (int (*main) (int, char **, char **),
  55                    int argc, char *__unbounded *__unbounded ubp_av,
  56                    void (*init) (void), void (*fini) (void),
  57                    void (*rtld_fini) (void), void *__unbounded stack_end)
  58 {
  59   char *__unbounded *__unbounded ubp_ev = &ubp_av[argc + 1];
  60 #if __BOUNDED_POINTERS__
  61   char **argv;
  62 #else
  63 # define argv ubp_av
  64 #endif
  65
  66 #ifndef SHARED
  67 # ifdef HAVE_AUX_VECTOR
  68   void *__unbounded *__unbounded auxvec;
  69 # endif
  70
  71   /* The next variable is only here to work around a bug in gcc <= 2.7.2.2.
  72      If the address would be taken inside the expression the optimizer
  73      would try to be too smart and throws it away.  Grrr.  */
  74   int *dummy_addr = &_dl_starting_up;
  75
  76   __libc_multiple_libcs = dummy_addr && !_dl_starting_up;
  77 #endif
  78
  79   INIT_ARGV_and_ENVIRON;
  80
  81   /* Store the lowest stack address.  */
  82   __libc_stack_end = stack_end;
  83
  84 #ifndef SHARED
  85 # ifdef HAVE_AUX_VECTOR
  86   /* First process the auxiliary vector since we need to find the
  87      program header to locate an eventually present PT_TLS entry.  */
  88   for (auxvec = (void *__unbounded *__unbounded) ubp_ev;
  89        *auxvec != NULL; ++auxvec);
  90   ++auxvec;
  91   _dl_aux_init ((ElfW(auxv_t) *) auxvec);
  92 # endif
  93
  94   /* Initialize the thread library at least a bit since the libgcc
  95      functions are using thread functions if these are available and
  96      we need to setup errno.  If there is no thread library and we
  97      handle TLS the function is defined in the libc to initialized the
  98      TLS handling.  */
  99 # if !(USE_TLS - 0)
 100   if (__pthread_initialize_minimal)
 101 # endif
 102     __pthread_initialize_minimal ();
 103
 104   /* Some security at this point.  Prevent starting a SUID binary where
 105      the standard file descriptors are not opened.  We have to do this
 106      only for statically linked applications since otherwise the dynamic
 107      loader did the work already.  */
 108   if (__builtin_expect (__libc_enable_secure, 0))
 109     __libc_check_standard_fds ();
 110 #endif
 111
 112   /* Register the destructor of the dynamic linker if there is any.  */
 113   if (__builtin_expect (rtld_fini != NULL, 1))
 114     __cxa_atexit ((void (*) (void *)) rtld_fini, NULL, NULL);
 115
 116   /* Call the initializer of the libc.  This is only needed here if we
 117      are compiling for the static library in which case we haven't
 118      run the constructors in `_dl_start_user'.  */
 119 #ifndef SHARED
 120   __libc_init_first (argc, argv, __environ);
 121 #endif
 122
 123   /* Register the destructor of the program, if any.  */
 124   if (fini)
 125     __cxa_atexit ((void (*) (void *)) fini, NULL, NULL);
 126
 127   /* Call the initializer of the program, if any.  */
 128 #ifdef SHARED
 129   if (__builtin_expect (GL(dl_debug_mask) & DL_DEBUG_IMPCALLS, 0))
 130     _dl_debug_printf ("\ninitialize program: %s\n\n", argv[0]);
 131 #endif
 132   if (init)
 133     (*init) ();
 134
 135 #ifdef SHARED
 136   if (__builtin_expect (GL(dl_debug_mask) & DL_DEBUG_IMPCALLS, 0))
 137     _dl_debug_printf ("\ntransferring control: %s\n\n", argv[0]);
 138 #endif
 139
 140   exit ((*main) (argc, argv, __environ));
 141 }