Re: [PATCH v2 1/6] mm: introduce vma->vm_flags modifier functions

Peter Zijlstra
2023-01-25T09:09:37Z

On Wed, Jan 25, 2023 at 12:38:46AM -0800, Suren Baghdasaryan wrote:

> diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
> index 2d6d790d9bed..6c7c70bf50dd 100644
> --- a/include/linux/mm_types.h
> +++ b/include/linux/mm_types.h
> @@ -491,7 +491,13 @@ struct vm_area_struct {
> * See vmf_insert_mixed_prot() for discussion.
> */
> pgprot_t vm_page_prot;
> - unsigned long vm_flags; /* Flags, see mm.h. */
> +
> + /*
> + * Flags, see mm.h.
> + * WARNING! Do not modify directly.
> + * Use {init|reset|set|clear|mod}_vm_flags() functions instead.
> + */
> + unsigned long vm_flags;

We have __private and ACCESS_PRIVATE() to help with enforcing this.