linux/arch/x86/mm/pkeys.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Intel Memory Protection Keys management
 * Copyright (c) 2015, Intel Corporation.
 */
#include <linux/debugfs.h>		/* debugfs_create_u32()		*/
#include <linux/mm_types.h>             /* mm_struct, vma, etc...       */
#include <linux/pkeys.h>                /* PKEY_*                       */
#include <uapi/asm-generic/mman-common.h>

#include <asm/cpufeature.h>             /* boot_cpu_has, ...            */
#include <asm/mmu_context.h>            /* vma_pkey()                   */

int __execute_only_pkey(struct mm_struct *mm)
{ … }

static inline bool vma_is_pkey_exec_only(struct vm_area_struct *vma)
{ … }

/*
 * This is only called for *plain* mprotect calls.
 */
int __arch_override_mprotect_pkey(struct vm_area_struct *vma, int prot, int pkey)
{ … }

#define PKRU_AD_MASK(pkey) …

/*
 * Make the default PKRU value (at execve() time) as restrictive
 * as possible.  This ensures that any threads clone()'d early
 * in the process's lifetime will not accidentally get access
 * to data which is pkey-protected later on.
 */
u32 init_pkru_value = …;

static ssize_t init_pkru_read_file(struct file *file, char __user *user_buf,
			     size_t count, loff_t *ppos)
{ … }

static ssize_t init_pkru_write_file(struct file *file,
		 const char __user *user_buf, size_t count, loff_t *ppos)
{ … }

static const struct file_operations fops_init_pkru = …;

static int __init create_init_pkru_value(void)
{ … }
late_initcall(create_init_pkru_value);

static __init int setup_init_pkru(char *opt)
{ … }
__setup(…);