>
> From: Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx>
>
> Check whether a VMA can be used with userfault in more compact way
>
> Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx>
> Signed-off-by: Andrea Arcangeli <aarcange@xxxxxxxxxx>
> ---
Acked-by: Hillf Danton <hillf.zj@xxxxxxxxxxxxxxx>
> fs/userfaultfd.c | 13 +++++++++----
> 1 file changed, 9 insertions(+), 4 deletions(-)
>
> diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
> index 9552734..387fe77 100644
> --- a/fs/userfaultfd.c
> +++ b/fs/userfaultfd.c
> @@ -1060,6 +1060,11 @@ static __always_inline int validate_range(struct mm_struct *mm,
> return 0;
> }
>
> +static inline bool vma_can_userfault(struct vm_area_struct *vma)
> +{
> + return vma_is_anonymous(vma) || is_vm_hugetlb_page(vma);
> +}
> +
> static int userfaultfd_register(struct userfaultfd_ctx *ctx,
> unsigned long arg)
> {
> @@ -1149,7 +1154,7 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx,
>
> /* check not compatible vmas */
> ret = -EINVAL;
> - if (!vma_is_anonymous(cur) && !is_vm_hugetlb_page(cur))
> + if (!vma_can_userfault(cur))
> goto out_unlock;
> /*
> * If this vma contains ending address, and huge pages
> @@ -1193,7 +1198,7 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx,
> do {
> cond_resched();
>
> - BUG_ON(!vma_is_anonymous(vma) && !is_vm_hugetlb_page(vma));
> + BUG_ON(!vma_can_userfault(vma));
> BUG_ON(vma->vm_userfaultfd_ctx.ctx &&
> vma->vm_userfaultfd_ctx.ctx != ctx);
>
> @@ -1331,7 +1336,7 @@ static int userfaultfd_unregister(struct userfaultfd_ctx *ctx,
> * provides for more strict behavior to notice
> * unregistration errors.
> */
> - if (!vma_is_anonymous(cur) && !is_vm_hugetlb_page(cur))
> + if (!vma_can_userfault(cur))
> goto out_unlock;
>
> found = true;
> @@ -1345,7 +1350,7 @@ static int userfaultfd_unregister(struct userfaultfd_ctx *ctx,
> do {
> cond_resched();
>
> - BUG_ON(!vma_is_anonymous(vma) && !is_vm_hugetlb_page(vma));
> + BUG_ON(!vma_can_userfault(vma));
>
> /*
> * Nothing to do: this vma is already registered into this
>
--
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