From d46644af7636c4cb876110c8ff7f1efbbb815bfe Mon Sep 17 00:00:00 2001 From: Muhammad Usama Anjum Date: Wed, 29 Apr 2026 15:57:04 +0530 Subject: mm: skip KASAN tagging for page-allocated page tables Page tables are always accessed via the linear mapping with a match-all tag, so HW-tag KASAN never checks them. For page-allocated tables (PTEs and PGDs etc), avoid the tag setup and poisoning overhead by using __GFP_SKIP_KASAN. SLUB-backed page tables are unchanged for now. (They aren't widely used and require more SLUB related skip logic. Leave it later.) Link: https://lore.kernel.org/20260429102704.680174-4-dev.jain@arm.com Signed-off-by: Muhammad Usama Anjum Signed-off-by: Dev Jain Reviewed-by: Ryan Roberts Reviewed-by: Catalin Marinas Acked-by: David Hildenbrand (Arm) Cc: Arnd Bergmann Cc: Ben Segall Cc: Dietmar Eggemann Cc: Ingo Molnar Cc: Juri Lelli Cc: Kees Cook Cc: K Prateek Nayak Cc: Liam Howlett Cc: Lorenzo Stoakes Cc: Mathieu Desnoyers Cc: Mel Gorman Cc: Michal Hocko Cc: Mike Rapoport Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Suren Baghdasaryan Cc: "Uladzislau Rezki (Sony)" Cc: Valentin Schneider Cc: Vincent Guittot Cc: Vlastimil Babka Signed-off-by: Andrew Morton --- include/asm-generic/pgalloc.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/asm-generic') diff --git a/include/asm-generic/pgalloc.h b/include/asm-generic/pgalloc.h index 57137d3ac159..051aa1331051 100644 --- a/include/asm-generic/pgalloc.h +++ b/include/asm-generic/pgalloc.h @@ -4,7 +4,7 @@ #ifdef CONFIG_MMU -#define GFP_PGTABLE_KERNEL (GFP_KERNEL | __GFP_ZERO) +#define GFP_PGTABLE_KERNEL (GFP_KERNEL | __GFP_ZERO | __GFP_SKIP_KASAN) #define GFP_PGTABLE_USER (GFP_PGTABLE_KERNEL | __GFP_ACCOUNT) /** -- cgit v1.2.3