From c11d34fa139e4b0fb4249a30f37b178353533fa1 Mon Sep 17 00:00:00 2001 From: Ryan Roberts Date: Fri, 2 Jun 2023 10:29:47 +0100 Subject: mm/damon/ops-common: atomically test and clear young on ptes and pmds It is racy to non-atomically read a pte, then clear the young bit, then write it back as this could discard dirty information. Further, it is bad practice to directly set a pte entry within a table. Instead clearing young must go through the arch-provided helper, ptep_test_and_clear_young() to ensure it is modified atomically and to give the arch code visibility and allow it to check (and potentially modify) the operation. Link: https://lkml.kernel.org/r/20230602092949.545577-3-ryan.roberts@arm.com Fixes: 3f49584b262c ("mm/damon: implement primitives for the virtual memory address spaces"). Signed-off-by: Ryan Roberts Reviewed-by: Zi Yan Reviewed-by: SeongJae Park Reviewed-by: Mike Rapoport (IBM) Cc: Christoph Hellwig Cc: Kirill A. Shutemov Cc: Lorenzo Stoakes Cc: Matthew Wilcox (Oracle) Cc: Uladzislau Rezki (Sony) Cc: Yu Zhao Cc: Signed-off-by: Andrew Morton --- mm/damon/ops-common.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'mm/damon/ops-common.h') diff --git a/mm/damon/ops-common.h b/mm/damon/ops-common.h index 14f4bc69f29b..18d837d11bce 100644 --- a/mm/damon/ops-common.h +++ b/mm/damon/ops-common.h @@ -9,8 +9,8 @@ struct folio *damon_get_folio(unsigned long pfn); -void damon_ptep_mkold(pte_t *pte, struct mm_struct *mm, unsigned long addr); -void damon_pmdp_mkold(pmd_t *pmd, struct mm_struct *mm, unsigned long addr); +void damon_ptep_mkold(pte_t *pte, struct vm_area_struct *vma, unsigned long addr); +void damon_pmdp_mkold(pmd_t *pmd, struct vm_area_struct *vma, unsigned long addr); int damon_cold_score(struct damon_ctx *c, struct damon_region *r, struct damos *s); -- cgit v1.2.3