diff options
| -rw-r--r-- | include/linux/page-flags.h | 14 | ||||
| -rw-r--r-- | mm/kfence/core.c | 14 | ||||
| -rw-r--r-- | mm/slab.h | 28 |
3 files changed, 25 insertions, 31 deletions
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) diff --git a/mm/kfence/core.c b/mm/kfence/core.c index 727c20c94ac5..e62b5516bf48 100644 --- a/mm/kfence/core.c +++ b/mm/kfence/core.c @@ -612,14 +612,15 @@ static unsigned long kfence_init_pool(void) * enters __slab_free() slow-path. */ for (i = 0; i < KFENCE_POOL_SIZE / PAGE_SIZE; i++) { - struct slab *slab; + struct page *page; if (!i || (i % 2)) continue; - slab = page_slab(pfn_to_page(start_pfn + i)); - __folio_set_slab(slab_folio(slab)); + page = pfn_to_page(start_pfn + i); + __SetPageSlab(page); #ifdef CONFIG_MEMCG + struct slab *slab = page_slab(page); slab->obj_exts = (unsigned long)&kfence_metadata_init[i / 2 - 1].obj_exts | MEMCG_DATA_OBJEXTS; #endif @@ -665,16 +666,17 @@ static unsigned long kfence_init_pool(void) reset_slab: for (i = 0; i < KFENCE_POOL_SIZE / PAGE_SIZE; i++) { - struct slab *slab; + struct page *page; if (!i || (i % 2)) continue; - slab = page_slab(pfn_to_page(start_pfn + i)); + page = pfn_to_page(start_pfn + i); #ifdef CONFIG_MEMCG + struct slab *slab = page_slab(page); slab->obj_exts = 0; #endif - __folio_clear_slab(slab_folio(slab)); + __ClearPageSlab(page); } return addr; diff --git a/mm/slab.h b/mm/slab.h index 078daecc7cf5..a64b9b2c8731 100644 --- a/mm/slab.h +++ b/mm/slab.h @@ -146,20 +146,24 @@ static_assert(IS_ALIGNED(offsetof(struct slab, freelist), sizeof(freelist_aba_t) struct slab *: (struct folio *)s)) /** - * page_slab - Converts from first struct page to slab. - * @p: The first (either head of compound or single) page of slab. + * page_slab - Converts from struct page to its slab. + * @page: A page which may or may not belong to a slab. * - * A temporary wrapper to convert struct page to struct slab in situations where - * we know the page is the compound head, or single order-0 page. - * - * Long-term ideally everything would work with struct slab directly or go - * through folio to struct slab. - * - * Return: The slab which contains this page + * Return: The slab which contains this page or NULL if the page does + * not belong to a slab. This includes pages returned from large kmalloc. */ -#define page_slab(p) (_Generic((p), \ - const struct page *: (const struct slab *)(p), \ - struct page *: (struct slab *)(p))) +static inline struct slab *page_slab(const struct page *page) +{ + unsigned long head; + + head = READ_ONCE(page->compound_head); + if (head & 1) + page = (struct page *)(head - 1); + if (data_race(page->page_type >> 24) != PGTY_slab) + page = NULL; + + return (struct slab *)page; +} /** * slab_page - The first struct page allocated for a slab |