linux_getcwd.c

/* $OpenBSD: linux_getcwd.c,v 1.2 2001/05/16 12:50:21 ho Exp $ */
/* $NetBSD: vfs_getcwd.c,v 1.3.2.3 1999/07/11 10:24:09 sommerfeld Exp $ */
/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 1999 The NetBSD Foundation, Inc.
 * Copyright (c) 2015 The FreeBSD Foundation
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Bill Sommerfeld.
 *
 * Portions of this software were developed by Edward Tomasz Napierala
 * under sponsorship from the FreeBSD Foundation.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/param.h>
#include <sys/malloc.h>
#include <sys/proc.h>
#include <sys/vnode.h>

#ifdef COMPAT_LINUX32
#include <machine/../linux32/linux.h>
#include <machine/../linux32/linux32_proto.h>
#else
#include <machine/../linux/linux.h>
#include <machine/../linux/linux_proto.h>
#endif
#include <compat/linux/linux_misc.h>

/*
 * Find pathname of process's current directory.
 */
int
linux_getcwd(struct thread *td, struct linux_getcwd_args *uap)
{
	char *buf, *retbuf;
	size_t buflen;
	int error;

	buflen = uap->bufsize;
	if (__predict_false(buflen < 2))
		return (ERANGE);
	if (buflen > LINUX_PATH_MAX)
		buflen = LINUX_PATH_MAX;

	buf = malloc(buflen, M_TEMP, M_WAITOK);
	error = vn_getcwd(buf, &retbuf, &buflen);
	if (error == ENOMEM)
		error = ERANGE;
	if (error == 0) {
		error = copyout(retbuf, uap->buf, buflen);
		if (error == 0)
			td->td_retval[0] = buflen;
	}
	free(buf, M_TEMP);
	return (error);
}