include/rdma/ib.h

/*
 * Copyright (c) 2010 Intel Corporation.  All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - 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.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#if !defined(_RDMA_IB_H)
#define _RDMA_IB_H

#include <linux/types.h>
#include <linux/sched.h>

/*
 * The IB interfaces that use write() as bi-directional ioctl() are
 * fundamentally unsafe, since there are lots of ways to trigger "write()"
 * calls from various contexts with elevated privileges. That includes the
 * traditional suid executable error message writes, but also various kernel
 * interfaces that can write to file descriptors.
 *
 * This function provides protection for the legacy API by restricting the
 * calling context.
 */
static inline bool ib_safe_file_access(struct file *filp)
{
	return filp->f_cred == current_cred() && segment_eq(get_fs(), USER_DS);
}

#endif /* _RDMA_IB_H */