Re: [PATCH 1/5] mm: introduce vma_is_stack() and vma_is_heap()

From: Christian Göttsche
Date: Tue Jul 18 2023 - 11:10:31 EST


On Wed, 12 Jul 2023 at 16:25, Kefeng Wang <wangkefeng.wang@xxxxxxxxxx> wrote:
>
> Introduce the two helpers for general use.
>
> Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
> ---
> include/linux/mm.h | 12 ++++++++++++
> 1 file changed, 12 insertions(+)
>
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index 1462cf15badf..0bbeb31ac750 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -926,6 +926,18 @@ static inline bool vma_is_anonymous(struct vm_area_struct *vma)
> return !vma->vm_ops;
> }
>
> +static inline bool vma_is_heap(struct vm_area_struct *vma)

What about declaring the parameters const to document in code these
functions do not modify any state, and allow callers to pass pointers
to const?

> +{
> + return vma->vm_start <= vma->vm_mm->brk &&
> + vma->vm_end >= vma->vm_mm->start_brk;
> +}
> +
> +static inline bool vma_is_stack(struct vm_area_struct *vma)
> +{
> + return vma->vm_start <= vma->vm_mm->start_stack &&
> + vma->vm_end >= vma->vm_mm->start_stack;
> +}
> +
> static inline bool vma_is_temporary_stack(struct vm_area_struct *vma)
> {
> int maybe_stack = vma->vm_flags & (VM_GROWSDOWN | VM_GROWSUP);
> --
> 2.41.0
>