/* Helper functions for manipulating memory protection keys.

   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/>.  */

#ifndef _ARCH_PKEY_H

#define _ARCH_PKEY_H

/* Return the value of the PKRU register.  */

static inline unsigned int

pkey_read (void)

{

  unsigned int result;

  __asm__ volatile (".byte 0x0f, 0x01, 0xee"

                    : "=a" (result) : "c" (0) : "rdx");

  return result;

}

/* Overwrite the PKRU register with VALUE.  */

static inline void

pkey_write (unsigned int value)

{

  __asm__ volatile (".byte 0x0f, 0x01, 0xef"

                    : : "a" (value), "c" (0), "d" (0));

}

#endif /* _ARCH_PKEY_H */