Re: [PATCH 1/3] mm: add apply_to_existing_pages helper

Andrey Ryabinin
2019-12-06T16:24:55Z

On 12/5/19 5:04 PM, Daniel Axtens wrote:
> apply_to_page_range takes an address range, and if any parts of it
> are not covered by the existing page table hierarchy, it allocates
> memory to fill them in.
>
> In some use cases, this is not what we want - we want to be able to
> operate exclusively on PTEs that are already in the tables.
>
> Add apply_to_existing_pages for this. Adjust the walker functions
> for apply_to_page_range to take 'create', which switches them between
> the old and new modes.
>
> This will be used in KASAN vmalloc.
>
> Signed-off-by: Daniel Axtens <dja@axtens.net>

Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>