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.)
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Muhammad Usama Anjum <usama.anjum@arm.com>
---
Changes since v1:
- Update description to mention SLUB-backed page tables are unchanged
---
include/asm-generic/pgalloc.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/asm-generic/pgalloc.h b/include/asm-generic/pgalloc.h
index 57137d3ac1592..051aa1331051c 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)
/**
--
2.47.3