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 #include <tls.h>
  33 #ifndef SHARED
  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   /* Result of the 'main' function.  */
  67   int result;
  68
  69 #ifndef SHARED
  70 # ifdef HAVE_AUX_VECTOR
  71   void *__unbounded *__unbounded auxvec;
  72 # endif
  73
  74   __libc_multiple_libcs = &_dl_starting_up && !_dl_starting_up;
  75 #endif
  76
  77   INIT_ARGV_and_ENVIRON;
  78
  79   /* Store the lowest stack address.  */
  80   __libc_stack_end = stack_end;
  81
  82 #ifndef SHARED
  83 # ifdef HAVE_AUX_VECTOR
  84   /* First process the auxiliary vector since we need to find the
  85      program header to locate an eventually present PT_TLS entry.  */
  86   for (auxvec = (void *__unbounded *__unbounded) ubp_ev;
  87        *auxvec != NULL; ++auxvec);
  88   ++auxvec;
  89   _dl_aux_init ((ElfW(auxv_t) *) auxvec);
  90 # endif
  91
  92   /* Initialize the thread library at least a bit since the libgcc
  93      functions are using thread functions if these are available and
  94      we need to setup errno.  If there is no thread library and we
  95      handle TLS the function is defined in the libc to initialized the
  96      TLS handling.  */
  97 # if !(USE_TLS - 0)
  98   if (__pthread_initialize_minimal)
  99 # endif
 100     __pthread_initialize_minimal ();
 101
 102   /* Some security at this point.  Prevent starting a SUID binary where
 103      the standard file descriptors are not opened.  We have to do this
 104      only for statically linked applications since otherwise the dynamic
 105      loader did the work already.  */
 106   if (__builtin_expect (__libc_enable_secure, 0))
 107     __libc_check_standard_fds ();
 108 #endif
 109
 110   /* Register the destructor of the dynamic linker if there is any.  */
 111   if (__builtin_expect (rtld_fini != NULL, 1))
 112     __cxa_atexit ((void (*) (void *)) rtld_fini, NULL, NULL);
 113
 114   /* Call the initializer of the libc.  This is only needed here if we
 115      are compiling for the static library in which case we haven't
 116      run the constructors in `_dl_start_user'.  */
 117 #ifndef SHARED
 118   __libc_init_first (argc, argv, __environ);
 119 #endif
 120
 121   /* Register the destructor of the program, if any.  */
 122   if (fini)
 123     __cxa_atexit ((void (*) (void *)) fini, NULL, NULL);
 124
 125   /* Call the initializer of the program, if any.  */
 126 #ifdef SHARED
 127   if (__builtin_expect (GL(dl_debug_mask) & DL_DEBUG_IMPCALLS, 0))
 128     _dl_debug_printf ("\ninitialize program: %s\n\n", argv[0]);
 129 #endif
 130   if (init)
 131     (*init) ();
 132
 133 #ifdef SHARED
 134   if (__builtin_expect (GL(dl_debug_mask) & DL_DEBUG_IMPCALLS, 0))
 135     _dl_debug_printf ("\ntransferring control: %s\n\n", argv[0]);
 136 #endif
 137
 138 #ifdef HAVE_CANCELBUF
 139   if (setjmp (THREAD_SELF->cancelbuf) == 0)
 140 #endif
 141     {
 142       /* XXX This is where the try/finally handling must be used.  */
 143
 144       result = main (argc, argv, __environ);
 145     }
 146 #ifdef HAVE_CANCELBUF
 147   else
 148     /* Not much left to do but to exit the thread, not the process.  */
 149     __exit_thread (0);
 150 #endif
 151
 152   exit (result);
 153 }