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 <unistd.h>
  26 #include <sys/mman.h>
  27 #include <sys/stat.h>
  28 #include <stdio-common/_itoa.h>
  29
  30 /* We have prototype anywhere.  */
  31 extern ssize_t __libc_write __P ((int __fd, __const __ptr_t __buf,
  32                                   size_t __n));
  33
  34 #ifndef MAP_ANON
  35 /* This is the only dl-sysdep.c function that is actually needed at run-time
  36    by _dl_map_object.  */
  37
  38 int
  39 _dl_sysdep_open_zero_fill (void)
  40 {
  41   return __open ("/dev/zero", O_RDONLY);
  42 }
  43 #endif
  44
  45 /* Read the whole contents of FILE into new mmap'd space with given
  46    protections.  *SIZEP gets the size of the file.  */
  47
  48 void *
  49 _dl_sysdep_read_whole_file (const char *file, size_t *sizep, int prot)
  50 {
  51   void *result;
  52   struct stat st;
  53   int fd = __open (file, O_RDONLY);
  54   if (fd < 0)
  55     return NULL;
  56   if (__fxstat (_STAT_VER, fd, &st) < 0
  57       /* No need to map the file if it is empty.  */
  58       || st.st_size == 0)
  59     result = NULL;
  60   else
  61     {
  62       /* Map a copy of the file contents.  */
  63       result = __mmap (0, st.st_size, prot,
  64 #ifdef MAP_COPY
  65                        MAP_COPY
  66 #else
  67                        MAP_PRIVATE
  68 #endif
  69 #ifdef MAP_FILE
  70                        | MAP_FILE
  71 #endif
  72                        , fd, 0);
  73       if (result == MAP_FAILED)
  74         result = NULL;
  75       else
  76         *sizep = st.st_size;
  77     }
  78   __close (fd);
  79   return result;
  80 }
  81
  82
  83 /* Descriptor to write debug messages to.  */
  84 int _dl_debug_fd = 2;
  85
  86
  87 void
  88 _dl_sysdep_output (int fd, const char *msg, ...)
  89 {
  90   va_list ap;
  91
  92   va_start (ap, msg);
  93   do
  94     {
  95       size_t len = strlen (msg);
  96       __libc_write (fd, msg, len);
  97       msg = va_arg (ap, const char *);
  98     }
  99   while (msg != NULL);
 100   va_end (ap);
 101 }
 102
 103
 104 void
 105 _dl_debug_message (int new_line, const char *msg, ...)
 106 {
 107   /* We print the strings we get passed one after the other but start all
 108      lines using the current PID.  */
 109   int pid = 0;
 110   va_list ap;
 111
 112   va_start (ap, msg);
 113   do
 114     if (msg[0] == '\0')
 115       /* Get the next argument.  */
 116       msg = va_arg (ap, const char *);
 117     else
 118       {
 119         const char *endp;
 120
 121         /* We actually will print something in this line.  So print the
 122            PID now if needed.  */
 123         if (new_line)
 124           {
 125             char buf[7];
 126             char *p;
 127             if (pid == 0)
 128               pid = __getpid ();
 129             assert (pid >= 0 && pid < 100000);
 130             p = _itoa_word (pid, &buf[5], 10, 0);
 131             while (p > buf)
 132               *--p = '0';
 133             buf[5] = ':';
 134             buf[6] = '\t';
 135             __libc_write (_dl_debug_fd, buf, 7);
 136             new_line = 0;
 137           }
 138
 139         endp = msg + strcspn (msg, "\n");
 140         if (*endp == '\0')
 141           {
 142             __libc_write (_dl_debug_fd, msg, endp - msg);
 143             msg = va_arg (ap, const char *);
 144           }
 145         else
 146           {
 147             __libc_write (_dl_debug_fd, msg, endp - msg + 1);
 148             msg = endp + 1;
 149             new_line = 1;
 150           }
 151       }
 152   while (msg != NULL);
 153   va_end (ap);
 154 }