Re: [PATCH 1/4] mm: Add optional close() to struct vm_special_mapping

[David Hildenbrand <david@xxxxxxxxxx>]

On 07.08.24 14:41, Michael Ellerman wrote:
> Add an optional close() callback to struct vm_special_mapping. It will
> be used, by powerpc at least, to handle unmapping of the VDSO.
>
> Suggested-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
> ---
>   include/linux/mm_types.h | 2 ++
>   mm/mmap.c                | 3 +++
>   2 files changed, 5 insertions(+)
>
> diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
> index 485424979254..ef32d87a3adc 100644
> --- a/include/linux/mm_types.h
> +++ b/include/linux/mm_types.h
> @@ -1313,6 +1313,8 @@ struct vm_special_mapping {
>   
>   	int (*mremap)(const struct vm_special_mapping *sm,
>   		     struct vm_area_struct *new_vma);
> +	void (*close)(const struct vm_special_mapping *sm,
> +		      struct vm_area_struct *vma);
>   };
>   
>   enum tlb_flush_reason {
> diff --git a/mm/mmap.c b/mm/mmap.c
> index d0dfc85b209b..24bd6aa9155c 100644
> --- a/mm/mmap.c
> +++ b/mm/mmap.c
> @@ -3624,6 +3624,9 @@ static vm_fault_t special_mapping_fault(struct vm_fault *vmf);
>    */
>   static void special_mapping_close(struct vm_area_struct *vma)
>   {
> +	const struct vm_special_mapping *sm = vma->vm_private_data;

I'm old-fashioned, I enjoy an empty line here ;)

> +	if (sm->close)
> +		sm->close(sm, vma);

Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>

--
Cheers,

David / dhildenb