update from main archive 961127
[glibc.git] / elf / dl-support.c
blob35710a0a74d405ed91cec9001a9c8605cf901992
1 /* Support for dynamic linking code in static libc.
2 Copyright (C) 1996 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
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.
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.
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. */
20 #include <assert.h>
21 #include <fcntl.h>
22 #include <unistd.h>
23 #include <sys/mman.h>
24 #include <sys/stat.h>
26 /* This file defines some things that for the dynamic linker are defined in
27 rtld.c and dl-sysdep.c in ways appropriate to bootstrap dynamic linking. */
29 extern char *__progname;
30 char **_dl_argv = &__progname; /* This is checked for some error messages. */
32 /* This defines the default search path for libraries.
33 For the dynamic linker it is set by -rpath when linking. */
34 const char *_dl_rpath = DEFAULT_RPATH;
36 /* This is the only dl-sysdep.c function that is actually needed at run-time
37 by _dl_map_object. */
39 int
40 _dl_sysdep_open_zero_fill (void)
42 return __open ("/dev/zero", O_RDONLY);
45 /* This should never be called. */
46 void
47 _dl_sysdep_fatal (void)
49 assert (! "_dl_sysdep_fatal called");
52 /* Read the whole contents of FILE into new mmap'd space with given
53 protections. *SIZEP gets the size of the file. */
55 void *
56 _dl_sysdep_read_whole_file (const char *file, size_t *sizep, int prot)
58 void *result;
59 struct stat st;
60 int fd = __open (file, O_RDONLY);
61 if (fd < 0)
62 return NULL;
63 if (__fstat (fd, &st) < 0)
64 result = NULL;
65 else
67 /* Map a copy of the file contents. */
68 result = __mmap (0, st.st_size, prot,
69 #ifdef MAP_COPY
70 MAP_COPY
71 #else
72 MAP_PRIVATE
73 #endif
74 #ifdef MAP_FILE
75 | MAP_FILE
76 #endif
77 , fd, 0);
78 if (result == (void *) -1)
79 result = NULL;
80 else
81 *sizep = st.st_size;
83 __close (fd);
84 return result;