Re: [PATCH v2 5/5] x86/kasan: Populate shadow for shared chunk of the CPU entry area

From: Peter Zijlstra
Date: Mon Nov 14 2022 - 12:39:14 EST


On Mon, Nov 14, 2022 at 05:44:00PM +0300, Andrey Ryabinin wrote:
> Going back kasan_populate_shadow() seems like safer and easier choice.
> The only disadvantage of it that we might waste 1 page, which is not
> much compared to the KASAN memory overhead.

So the below delta?

---
--- a/arch/x86/mm/kasan_init_64.c
+++ b/arch/x86/mm/kasan_init_64.c
@@ -388,7 +388,7 @@ void __init kasan_init(void)
shadow_cea_end = kasan_mem_to_shadow_align_up(CPU_ENTRY_AREA_BASE +
CPU_ENTRY_AREA_MAP_SIZE);

- kasan_populate_early_shadow(
+ kasan_populate_shadow(
kasan_mem_to_shadow((void *)PAGE_OFFSET + MAXMEM),
kasan_mem_to_shadow((void *)VMALLOC_START));