/* Changing the per-thread memory protection key, x86_64 version.

   Copyright (C) 2017-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.  */

#include <arch-pkey.h>

#include <errno.h>

int

pkey_set (int key, unsigned int rights)

{

  if (key < 0 || key > 15 || rights > 3)

    {

      __set_errno (EINVAL);

      return -1;

    }

  unsigned int mask = 3 << (2 * key);

  unsigned int pkru = pkey_read ();

  pkru = (pkru & ~mask) | (rights << (2 * key));

  pkey_write (pkru);

  return 0;

}