[PATCH] arm: kasan: Use memblock_alloc_try_nid_raw for shadow page allocation

From: Mark-PK Tsai
Date: Mon Jul 31 2023 - 08:06:27 EST


kasan_pte_populate fill KASAN_SHADOW_INIT in the newly
allocated shadow page, so it's unnecessary to
use memblock_alloc_try_nid, which always zero the
new allocated memory.

Use memblock_alloc_try_nid_raw instead of
memblock_alloc_try_nid like arm64 does which
can make kasan init faster.

Signed-off-by: Mark-PK Tsai <mark-pk.tsai@xxxxxxxxxxxx>
---
arch/arm/mm/kasan_init.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mm/kasan_init.c b/arch/arm/mm/kasan_init.c
index 24d71b5db62d..111d4f703136 100644
--- a/arch/arm/mm/kasan_init.c
+++ b/arch/arm/mm/kasan_init.c
@@ -28,6 +28,12 @@ static pgd_t tmp_pgd_table[PTRS_PER_PGD] __initdata __aligned(PGD_SIZE);

pmd_t tmp_pmd_table[PTRS_PER_PMD] __page_aligned_bss;

+static __init void *kasan_alloc_block_raw(size_t size)
+{
+ return memblock_alloc_try_nid_raw(size, size, __pa(MAX_DMA_ADDRESS),
+ MEMBLOCK_ALLOC_NOLEAKTRACE, NUMA_NO_NODE);
+}
+
static __init void *kasan_alloc_block(size_t size)
{
return memblock_alloc_try_nid(size, size, __pa(MAX_DMA_ADDRESS),
@@ -50,7 +56,7 @@ static void __init kasan_pte_populate(pmd_t *pmdp, unsigned long addr,
if (!pte_none(READ_ONCE(*ptep)))
continue;

- p = kasan_alloc_block(PAGE_SIZE);
+ p = kasan_alloc_block_raw(PAGE_SIZE);
if (!p) {
panic("%s failed to allocate shadow page for address 0x%lx\n",
__func__, addr);
--
2.18.0