glibc/sysdeps/unix/sysv/linux/x86/arch-pkey.h

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/* Helper functions for manipulating memory protection keys.
Copyright (C) 2017-2019 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 */