1/*
2 * Copyright (c) 1991, 1992 Paul Kranenburg <pk@cs.few.eur.nl>
3 * Copyright (c) 1993 Branko Lankester <branko@hacktic.nl>
4 * Copyright (c) 1993-1996 Rick Sladkey <jrs@world.std.com>
5 * Copyright (c) 1996-1999 Wichert Akkerman <wichert@cistron.nl>
6 * Copyright (c) 2006 Ulrich Drepper <drepper@redhat.com>
7 * Copyright (c) 2006 Bernhard Kaindl <bk@suse.de>
8 * Copyright (c) 2006-2015 Dmitry V. Levin <ldv@altlinux.org>
9 * Copyright (c) 2014-2017 The strace developers.
10 * All rights reserved.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 *    notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 *    notice, this list of conditions and the following disclaimer in the
19 *    documentation and/or other materials provided with the distribution.
20 * 3. The name of the author may not be used to endorse or promote products
21 *    derived from this software without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
24 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
25 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
26 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
27 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
28 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
29 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
30 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
32 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33 */
34
35#include "defs.h"
36
37static int
38decode_readlink(struct tcb *tcp, int offset)
39{
40	if (entering(tcp)) {
41		printpath(tcp, tcp->u_arg[offset]);
42		tprints(", ");
43	} else {
44		if (syserror(tcp))
45			printaddr(tcp->u_arg[offset + 1]);
46		else
47			/* Used to use printpathn(), but readlink
48			 * neither includes NUL in the returned count,
49			 * nor actually writes it into memory.
50			 * printpathn() would decide on printing
51			 * "..." continuation based on garbage
52			 * past return buffer's end.
53			 */
54			printstrn(tcp, tcp->u_arg[offset + 1], tcp->u_rval);
55		tprintf(", %" PRI_klu, tcp->u_arg[offset + 2]);
56	}
57	return 0;
58}
59
60SYS_FUNC(readlink)
61{
62	return decode_readlink(tcp, 0);
63}
64
65SYS_FUNC(readlinkat)
66{
67	if (entering(tcp))
68		print_dirfd(tcp, tcp->u_arg[0]);
69	return decode_readlink(tcp, 1);
70}
71