sysdeps/generic/libc-start.c

   1 /* Copyright (C) 1998, 1999, 2000 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 /* Prototype for local function.  */
  37 extern void __libc_check_standard_fds (void);
  38
  39 int
  40 /* GKM FIXME: GCC: this should get __BP_ prefix by virtue of the
  41    BPs in the arglist of startup_info.main and startup_info.init. */
  42 BP_SYM (__libc_start_main) (int (*main) (int, char **, char **),
  43                    int argc, char *__unbounded *__unbounded ubp_av,
  44                    void (*init) (void), void (*fini) (void),
  45                    void (*rtld_fini) (void), void *__unbounded stack_end)
  46 {
  47   char *__unbounded *__unbounded ubp_ev = &ubp_av[argc + 1];
  48 #if __BOUNDED_POINTERS__
  49   char **argv;
  50 #else
  51 # define argv ubp_av
  52 #endif
  53
  54 #ifndef SHARED
  55   /* The next variable is only here to work around a bug in gcc <= 2.7.2.2.
  56      If the address would be taken inside the expression the optimizer
  57      would try to be too smart and throws it away.  Grrr.  */
  58   int *dummy_addr = &_dl_starting_up;
  59
  60   __libc_multiple_libcs = dummy_addr && !_dl_starting_up;
  61 #endif
  62
  63   INIT_ARGV_and_ENVIRON;
  64
  65   /* Store the lowest stack address.  */
  66   __libc_stack_end = stack_end;
  67
  68 #ifndef SHARED
  69   /* Initialize the thread library at least a bit since the libgcc
  70      functions are using thread functions if these are available and
  71      we need to setup errno.  */
  72   if (__pthread_initialize_minimal)
  73     __pthread_initialize_minimal ();
  74
  75   /* Some security at this point.  Prevent starting a SUID binary where
  76      the standard file descriptors are not opened.  We have to do this
  77      only for statically linked applications since otherwise the dynamic
  78      loader did the work already.  */
  79   if (__builtin_expect (__libc_enable_secure, 0))
  80     __libc_check_standard_fds ();
  81 #endif
  82
  83   /* Register the destructor of the dynamic linker if there is any.  */
  84   if (__builtin_expect (rtld_fini != NULL, 1))
  85     atexit (rtld_fini);
  86
  87   /* Call the initializer of the libc.  This is only needed here if we
  88      are compiling for the static library in which case we haven't
  89      run the constructors in `_dl_start_user'.  */
  90 #ifndef SHARED
  91   __libc_init_first (argc, argv, __environ);
  92 #endif
  93
  94   /* Register the destructor of the program, if any.  */
  95   if (fini)
  96     atexit (fini);
  97
  98   /* Call the initializer of the program, if any.  */
  99 #ifdef SHARED
 100   if (__builtin_expect (_dl_debug_impcalls, 0))
 101     _dl_debug_message (1, "\ninitialize program: ", argv[0], "\n\n", NULL);
 102 #endif
 103   if (init)
 104     (*init) ();
 105
 106 #ifdef SHARED
 107   if (__builtin_expect (_dl_debug_impcalls, 0))
 108     _dl_debug_message (1, "\ntransferring control: ", argv[0], "\n\n", NULL);
 109 #endif
 110
 111   exit ((*main) (argc, argv, __environ));
 112 }