mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-04 02:40:06 +00:00
a803367bab
The 32-bit protection key behavior is somewhat unclear on 32-bit powerpc, so this change is restricted to the 64-bit variants. Flag translation is needed because of hardware differences between the POWER implementation (read and write flags) and the Intel implementation (write and read+write flags).
56 lines
1.8 KiB
C
56 lines
1.8 KiB
C
/* Helper functions for manipulating memory protection keys, for powerpc64.
|
|
Copyright (C) 2017-2020 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
|
|
|
|
/* Read and write access bits in the AMR register. Needs to be
|
|
translated from and to PKEY_DISABLE_* flags. */
|
|
#define PKEY_AMR_READ 1UL
|
|
#define PKEY_AMR_WRITE 2UL
|
|
|
|
/* Return the value of the AMR register. */
|
|
static inline unsigned long int
|
|
pkey_read (void)
|
|
{
|
|
unsigned long int result;
|
|
__asm__ volatile ("mfspr %0, 13" : "=r" (result));
|
|
return result;
|
|
}
|
|
|
|
/* Overwrite the AMR register with VALUE. */
|
|
static inline void
|
|
pkey_write (unsigned long int value)
|
|
{
|
|
__asm__ volatile ("mtspr 13, %0" : : "r" (value));
|
|
}
|
|
|
|
/* Number of the largest supported key. This depends on the width of
|
|
the AMR register. */
|
|
#define PKEY_MAX (sizeof (unsigned long int) * 8 / 2 - 1)
|
|
_Static_assert (PKEY_MAX == 15 || PKEY_MAX == 31, "PKEY_MAX value");
|
|
|
|
/* Translate key number into AMR index position. */
|
|
static inline int
|
|
pkey_index (int key)
|
|
{
|
|
return 2 * (PKEY_MAX - key);
|
|
}
|
|
|
|
#endif /* _ARCH_PKEY_H */
|