mirror of
https://sourceware.org/git/glibc.git
synced 2025-07-30 22:43:12 +03:00
114 lines
3.9 KiB
C
114 lines
3.9 KiB
C
/* Changing the per-thread memory protection key, AArch64 version.
|
|
Copyright (C) 2024-2025 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
|
|
<https://www.gnu.org/licenses/>. */
|
|
|
|
#include <arch-pkey.h>
|
|
#include <errno.h>
|
|
#include <sys/mman.h>
|
|
|
|
#define MAX_PKEY_RIGHTS (PKEY_DISABLE_ACCESS | \
|
|
PKEY_DISABLE_WRITE | PKEY_DISABLE_EXECUTE | PKEY_DISABLE_READ)
|
|
|
|
int
|
|
pkey_set (int key, unsigned int restrictions)
|
|
{
|
|
if (key < 0 || key > 15 || restrictions > MAX_PKEY_RIGHTS)
|
|
{
|
|
__set_errno (EINVAL);
|
|
return -1;
|
|
}
|
|
unsigned long mask = S1POE_PERM_MASK << (S1POE_BITS_PER_POI * key);
|
|
unsigned long por_el0 = pkey_read ();
|
|
unsigned long perm;
|
|
|
|
/* POR ot PKEY mapping: -WXR
|
|
PKEY_UNRESTRICTED => 0111 (read-write-execute)
|
|
PKEY_DISABLE_ACCESS => removes R and W access
|
|
PKEY_DISABLE_READ => removes R access
|
|
PKEY_DISABLE_WRITE => removes W access
|
|
PKEY_DISABLE_EXECUTE => removes X access
|
|
|
|
Either of PKEY_DISABLE_ACCESS or PKEY_DISABLE_READ removes R access.
|
|
Either of PKEY_DISABLE_ACCESS or PKEY_DISABLE_WRITE removes W access.
|
|
Using PKEY_DISABLE_ACCESS along with only one of PKEY_DISABLE_READ or
|
|
PKEY_DISABLE_WRITE is considered to be in error.
|
|
|
|
Furthermore, for avoidance of doubt:
|
|
|
|
PKEY flags Permissions
|
|
rxwa -WXR
|
|
1111 => 0000 S1POE_PERM_NO_ACCESS
|
|
1110 => 0000 S1POE_PERM_NO_ACCESS
|
|
1101 => EINVAL
|
|
1100 => 0100 S1POE_PERM_W
|
|
1011 => 0010 S1POE_PERM_X
|
|
1010 => 0010 S1POE_PERM_X
|
|
1001 => EINVAL
|
|
1000 => 0110 S1POE_PERM_WX
|
|
0111 => EINVAL
|
|
0110 => 0001 S1POE_PERM_R
|
|
0101 => 0000 S1POE_PERM_NO_ACCESS
|
|
0100 => 0101 S1POE_PERM_RW
|
|
0011 => EINVAL
|
|
0010 => 0011 S1POE_PERM_RX
|
|
0001 => 0010 S1POE_PERM_X
|
|
0000 => 0111 S1POE_PERM_RWX */
|
|
switch (restrictions)
|
|
{
|
|
case PKEY_DISABLE_ACCESS | PKEY_DISABLE_READ | PKEY_DISABLE_WRITE
|
|
| PKEY_DISABLE_EXECUTE:
|
|
case PKEY_DISABLE_ACCESS | PKEY_DISABLE_EXECUTE:
|
|
case PKEY_DISABLE_ACCESS | PKEY_DISABLE_READ | PKEY_DISABLE_EXECUTE:
|
|
case PKEY_DISABLE_ACCESS | PKEY_DISABLE_WRITE | PKEY_DISABLE_EXECUTE:
|
|
case PKEY_DISABLE_READ | PKEY_DISABLE_WRITE | PKEY_DISABLE_EXECUTE:
|
|
perm = S1POE_PERM_NO_ACCESS;
|
|
break;
|
|
case PKEY_DISABLE_READ | PKEY_DISABLE_EXECUTE:
|
|
perm = S1POE_PERM_W;
|
|
break;
|
|
case PKEY_DISABLE_ACCESS | PKEY_DISABLE_READ:
|
|
case PKEY_DISABLE_ACCESS | PKEY_DISABLE_WRITE:
|
|
case PKEY_DISABLE_ACCESS | PKEY_DISABLE_READ | PKEY_DISABLE_WRITE:
|
|
case PKEY_DISABLE_READ | PKEY_DISABLE_WRITE:
|
|
case PKEY_DISABLE_ACCESS:
|
|
perm = S1POE_PERM_X;
|
|
break;
|
|
case PKEY_DISABLE_READ:
|
|
perm = S1POE_PERM_WX;
|
|
break;
|
|
case PKEY_DISABLE_WRITE | PKEY_DISABLE_EXECUTE:
|
|
perm = S1POE_PERM_R;
|
|
break;
|
|
case PKEY_DISABLE_EXECUTE:
|
|
perm = S1POE_PERM_RW;
|
|
break;
|
|
case PKEY_DISABLE_WRITE:
|
|
perm = S1POE_PERM_RX;
|
|
break;
|
|
case PKEY_UNRESTRICTED:
|
|
perm = S1POE_PERM_RWX;
|
|
break;
|
|
default:
|
|
__set_errno (EINVAL);
|
|
return -1;
|
|
}
|
|
|
|
por_el0 = (por_el0 & ~mask) | (perm << (S1POE_BITS_PER_POI * key));
|
|
pkey_write (por_el0);
|
|
return 0;
|
|
}
|