elf/dl-misc.c

   1 /* Miscellaneous support functions for dynamic linker
   2    Copyright (C) 1997, 1998 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Library General Public License as
   7    published by the Free Software Foundation; either version 2 of the
   8    License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Library General Public License for more details.
  14
  15    You should have received a copy of the GNU Library General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  17    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18    Boston, MA 02111-1307, USA.  */
  19
  20 #include <assert.h>
  21 #include <fcntl.h>
  22 #include <unistd.h>
  23 #include <stdarg.h>
  24 #include <string.h>
  25 #include <sys/mman.h>
  26 #include <sys/stat.h>
  27
  28 #ifndef MAP_ANON
  29 /* This is the only dl-sysdep.c function that is actually needed at run-time
  30    by _dl_map_object.  */
  31
  32 int
  33 _dl_sysdep_open_zero_fill (void)
  34 {
  35   return __open ("/dev/zero", O_RDONLY);
  36 }
  37 #endif
  38
  39 /* Read the whole contents of FILE into new mmap'd space with given
  40    protections.  *SIZEP gets the size of the file.  */
  41
  42 void *
  43 _dl_sysdep_read_whole_file (const char *file, size_t *sizep, int prot)
  44 {
  45   void *result;
  46   struct stat st;
  47   int fd = __open (file, O_RDONLY);
  48   if (fd < 0)
  49     return NULL;
  50   if (__fxstat (_STAT_VER, fd, &st) < 0
  51       /* No need to map the file if it is empty.  */
  52       || st.st_size == 0)
  53     result = NULL;
  54   else
  55     {
  56       /* Map a copy of the file contents.  */
  57       result = __mmap (0, st.st_size, prot,
  58 #ifdef MAP_COPY
  59                        MAP_COPY
  60 #else
  61                        MAP_PRIVATE
  62 #endif
  63 #ifdef MAP_FILE
  64                        | MAP_FILE
  65 #endif
  66                        , fd, 0);
  67       if (result == MAP_FAILED)
  68         result = NULL;
  69       else
  70         *sizep = st.st_size;
  71     }
  72   __close (fd);
  73   return result;
  74 }
  75
  76
  77 /* Descriptor to write debug messages to.  */
  78 int _dl_debug_fd;
  79
  80
  81 void
  82 _dl_sysdep_output (int fd, const char *msg, ...)
  83 {
  84   va_list ap;
  85
  86   va_start (ap, msg);
  87   do
  88     {
  89       size_t len = strlen (msg);
  90       __write (fd, msg, len);
  91       msg = va_arg (ap, const char *);
  92     } while (msg);
  93   va_end (ap);
  94 }