1 /* Reading the per-thread memory protection key, powerpc64 version.
2    Copyright (C) 2017-2022 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    <http://www.gnu.org/licenses/>.  */
18 
19 #include <arch-pkey.h>
20 #include <errno.h>
21 #include <sys/mman.h>
22 
23 int
pkey_get(int key)24 pkey_get (int key)
25 {
26   if (key < 0 || key > PKEY_MAX)
27     {
28       __set_errno (EINVAL);
29       return -1;
30     }
31   unsigned int index = pkey_index (key);
32   unsigned long int amr = pkey_read ();
33   unsigned int bits = (amr >> index) & 3;
34 
35   /* Translate from AMR values.  PKEY_AMR_READ standing alone is not
36      currently representable.  */
37   if (bits & PKEY_AMR_READ)
38     return PKEY_DISABLE_ACCESS;
39   else if (bits == PKEY_AMR_WRITE)
40     return PKEY_DISABLE_WRITE;
41   return 0;
42 }
43