1 /* Changing the per-thread memory protection key, x86_64 version.
2 Copyright (C) 2017-2021 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19 #include <arch-pkey.h>
20 #include <errno.h>
21
22 int
pkey_set(int key,unsigned int rights)23 pkey_set (int key, unsigned int rights)
24 {
25 if (key < 0 || key > 15 || rights > 3)
26 {
27 __set_errno (EINVAL);
28 return -1;
29 }
30 unsigned int mask = 3 << (2 * key);
31 unsigned int pkru = pkey_read ();
32 pkru = (pkru & ~mask) | (rights << (2 * key));
33 pkey_write (pkru);
34 return 0;
35 }
36