linux-imx

// SPDX-License-Identifier: GPL-2.0

/*

 *  linux/mm/madvise.c

 *

 * Copyright (C) 1999  Linus Torvalds

 * Copyright (C) 2002  Christoph Hellwig

 */

​

#include <linux/mman.h>

#include <linux/pagemap.h>

#include <linux/syscalls.h>

#include <linux/mempolicy.h>

#include <linux/page-isolation.h>

#include <linux/userfaultfd_k.h>

#include <linux/hugetlb.h>

#include <linux/falloc.h>

#include <linux/sched.h>

#include <linux/ksm.h>

#include <linux/fs.h>

#include <linux/file.h>

#include <linux/blkdev.h>

#include <linux/backing-dev.h>

#include <linux/swap.h>

#include <linux/swapops.h>

#include <linux/shmem_fs.h>

#include <linux/mmu_notifier.h>

​

#include <asm/tlb.h>

​

#include "internal.h"

​

/*

 * Any behaviour which results in changes to the vma->vm_flags needs to

 * take mmap_sem for writing. Others, which simply traverse vmas, need

 * to only take it for reading.

 */

static int madvise_need_mmap_write(int behavior)

{

    switch (behavior) {

    case MADV_REMOVE:

    case MADV_WILLNEED:

    case MADV_DONTNEED:

    case MADV_FREE:

        return 0;

    default:

        /* be safe, default to 1. list exceptions explicitly */

        return 1;

    }

}

​

/*

 * We can potentially split a vm area into separate

 * areas, each area with its own behavior.

 */

static long madvise_behavior(struct vm_area_struct *vma,

             struct vm_area_struct **prev,

             unsigned long start, unsigned long end, int behavior)

{

    struct mm_struct *mm = vma->vm_mm;

    int error = 0;

    pgoff_t pgoff;

    unsigned long new_flags = vma->vm_flags;

​