[PATCH V2] mm/ptdump: Replace READ_ONCE() with standard page table accessors
From: Anshuman Khandual
Date: Wed Oct 01 2025 - 00:25:26 EST
Replace READ_ONCE() with standard page table accessors i.e pxdp_get() which
anyways default into READ_ONCE() in cases where platform does not override.
Also convert ptep_get_lockless() into ptep_get() as well.
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: linux-mm@xxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Reviewed-by: Dev Jain <dev.jain@xxxxxxx>
Acked-by: Lance Yang <lance.yang@xxxxxxxxx>
Acked-by: SeongJae Park <sj@xxxxxxxxxx>
Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
---
Changes in V2:
- Replaced ptep_get_lockless() with ptep_get() per David
Changes in V1:
https://lore.kernel.org/all/20250930025246.1143340-1-anshuman.khandual@xxxxxxx/
mm/ptdump.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/mm/ptdump.c b/mm/ptdump.c
index b600c7f864b8..973020000096 100644
--- a/mm/ptdump.c
+++ b/mm/ptdump.c
@@ -31,7 +31,7 @@ static int ptdump_pgd_entry(pgd_t *pgd, unsigned long addr,
unsigned long next, struct mm_walk *walk)
{
struct ptdump_state *st = walk->private;
- pgd_t val = READ_ONCE(*pgd);
+ pgd_t val = pgdp_get(pgd);
#if CONFIG_PGTABLE_LEVELS > 4 && \
(defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS))
@@ -54,7 +54,7 @@ static int ptdump_p4d_entry(p4d_t *p4d, unsigned long addr,
unsigned long next, struct mm_walk *walk)
{
struct ptdump_state *st = walk->private;
- p4d_t val = READ_ONCE(*p4d);
+ p4d_t val = p4dp_get(p4d);
#if CONFIG_PGTABLE_LEVELS > 3 && \
(defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS))
@@ -77,7 +77,7 @@ static int ptdump_pud_entry(pud_t *pud, unsigned long addr,
unsigned long next, struct mm_walk *walk)
{
struct ptdump_state *st = walk->private;
- pud_t val = READ_ONCE(*pud);
+ pud_t val = pudp_get(pud);
#if CONFIG_PGTABLE_LEVELS > 2 && \
(defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS))
@@ -100,7 +100,7 @@ static int ptdump_pmd_entry(pmd_t *pmd, unsigned long addr,
unsigned long next, struct mm_walk *walk)
{
struct ptdump_state *st = walk->private;
- pmd_t val = READ_ONCE(*pmd);
+ pmd_t val = pmdp_get(pmd);
#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
if (pmd_page(val) == virt_to_page(lm_alias(kasan_early_shadow_pte)))
@@ -121,7 +121,7 @@ static int ptdump_pte_entry(pte_t *pte, unsigned long addr,
unsigned long next, struct mm_walk *walk)
{
struct ptdump_state *st = walk->private;
- pte_t val = ptep_get_lockless(pte);
+ pte_t val = ptep_get(pte);
if (st->effective_prot_pte)
st->effective_prot_pte(st, val);
--
2.30.2