Re: [PATCH v4 01/16] slab: Reimplement page_slab()

[Harry Yoo <harry.yoo@oracle.com>]

On Thu, Nov 13, 2025 at 12:09:15AM +0000, Matthew Wilcox (Oracle) wrote:
> In order to separate slabs from folios, we need to convert from any page
> in a slab to the slab directly without going through a page to folio
> conversion first.
> 
> Up to this point, page_slab() has followed the example of other memdesc
> converters (page_folio(), page_ptdesc() etc) and just cast the pointer
> to the requested type, regardless of whether the pointer is actually a
> pointer to the correct type or not.
> 
> That changes with this commit; we check that the page actually belongs
> to a slab and return NULL if it does not.  Other memdesc converters will
> adopt this convention in future.
> 
> kfence was the only user of page_slab(), so adjust it to the new way
> of working.  It will need to be touched again when we separate slab
> from page.
> 
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
> Cc: Alexander Potapenko <glider@google.com>
> Cc: Marco Elver <elver@google.com>
> Cc: kasan-dev@googlegroups.com
> ---

Looks good to me,
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>

-- 
Cheers,
Harry / Hyeonggon