strace/readlink.c

51 lines
1.3 KiB
C

/*
* Copyright (c) 1991, 1992 Paul Kranenburg <pk@cs.few.eur.nl>
* Copyright (c) 1993 Branko Lankester <branko@hacktic.nl>
* Copyright (c) 1993-1996 Rick Sladkey <jrs@world.std.com>
* Copyright (c) 1996-1999 Wichert Akkerman <wichert@cistron.nl>
* Copyright (c) 2006 Ulrich Drepper <drepper@redhat.com>
* Copyright (c) 2006 Bernhard Kaindl <bk@suse.de>
* Copyright (c) 2006-2015 Dmitry V. Levin <ldv@altlinux.org>
* Copyright (c) 2014-2018 The strace developers.
* All rights reserved.
*
* SPDX-License-Identifier: LGPL-2.1-or-later
*/
#include "defs.h"
static int
decode_readlink(struct tcb *tcp, int offset)
{
if (entering(tcp)) {
printpath(tcp, tcp->u_arg[offset]);
tprints(", ");
} else {
if (syserror(tcp))
printaddr(tcp->u_arg[offset + 1]);
else
/* Used to use printpathn(), but readlink
* neither includes NUL in the returned count,
* nor actually writes it into memory.
* printpathn() would decide on printing
* "..." continuation based on garbage
* past return buffer's end.
*/
printstrn(tcp, tcp->u_arg[offset + 1], tcp->u_rval);
tprintf(", %" PRI_klu, tcp->u_arg[offset + 2]);
}
return 0;
}
SYS_FUNC(readlink)
{
return decode_readlink(tcp, 0);
}
SYS_FUNC(readlinkat)
{
if (entering(tcp))
print_dirfd(tcp, tcp->u_arg[0]);
return decode_readlink(tcp, 1);
}