From 2bcd3800f2da1be13b972858f63c66d035b1ec6d Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Thu, 13 Nov 2025 00:09:15 +0000 Subject: slab: Reimplement page_slab() 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) Cc: Alexander Potapenko Cc: Marco Elver Cc: kasan-dev@googlegroups.com Link: https://patch.msgid.link/20251113000932.1589073-2-willy@infradead.org Acked-by: David Hildenbrand (Red Hat) Tested-by: Marco Elver Reviewed-by: Harry Yoo Signed-off-by: Vlastimil Babka --- include/linux/page-flags.h | 14 +------------- 1 file changed, 1 insertion(+), 13 deletions(-) (limited to 'include/linux') diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index 0091ad1986bf..6d5e44968eab 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -1048,19 +1048,7 @@ PAGE_TYPE_OPS(Table, table, pgtable) */ PAGE_TYPE_OPS(Guard, guard, guard) -FOLIO_TYPE_OPS(slab, slab) - -/** - * PageSlab - Determine if the page belongs to the slab allocator - * @page: The page to test. - * - * Context: Any context. - * Return: True for slab pages, false for any other kind of page. - */ -static inline bool PageSlab(const struct page *page) -{ - return folio_test_slab(page_folio(page)); -} +PAGE_TYPE_OPS(Slab, slab, slab) #ifdef CONFIG_HUGETLB_PAGE FOLIO_TYPE_OPS(hugetlb, hugetlb) -- cgit