[PATCH RFC v3 08/21] mm: vmscan: remove stack copy address of pud/pmd pass in walk_pud/pmd_range()

[Yeoreum Yun]

The behaviour of pXdp_get() will change with generic compile-time folded
page tables. To prepare for that, replace passing the address of a stack
copy of a pud/pmd to walk_pmd/pte_range() with passing the pud/pmd pointer
directly so that  makes allowing folded entries to be ignored and
check the concurrent access proeprly otherwise pXd_same() would return
always true.

There should be no functional change.

Reviewed-by: Muhammad Usama Anjum <usama.anjum@xxxxxxx>
Signed-off-by: Yeoreum Yun <yeoreum.yun@xxxxxxx>
---
 mm/vmscan.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 4d51b0d8e287..4e98088becab 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -3777,7 +3777,7 @@ static void walk_pmd_range(pud_t *pud, unsigned long start, unsigned long end,
 
 		walk->mm_stats[MM_NONLEAF_FOUND]++;
 
-		if (!walk_pte_range(&val, addr, next, args))
+		if (!walk_pte_range(pmd + i, addr, next, args))
 			continue;
 
 		walk->mm_stats[MM_NONLEAF_ADDED]++;
@@ -3813,7 +3813,7 @@ static int walk_pud_range(p4d_t *p4d, unsigned long start, unsigned long end,
 		if (!pud_present(val) || WARN_ON_ONCE(pud_leaf(val)))
 			continue;
 
-		walk_pmd_range(&val, addr, next, args);
+		walk_pmd_range(pud + i, addr, next, args);
 
 		if (need_resched() || walk->batched >= MAX_LRU_BATCH) {
 			end = (addr | ~PUD_MASK) + 1;

-- 
2.43.0