[PATCH] arm64: mm: fix passing the incorrect 'CONT_PTES' for non-batched APIs

Baolin Wang baolin.wang at linux.alibaba.com
Wed Dec 24 02:54:07 PST 2025


Since contpte_test_and_clear_young_ptes() and contpte_clear_flush_young_ptes
have  already performed CONT_PTE_SIZE alignment and will clear the young flag
for the entire cont block, Their non-batched callers do not need to pass in
'CONT_PTES' to specify the cont block range. Otherwise, it may exceed the
range of a single cont block for the non-batched cases.

Signed-off-by: Baolin Wang <baolin.wang at linux.alibaba.com>
---
Hi Andrew,

As I conducted more tests, I found that the ptep_test_and_clear_young() operation
may clear the young flag beyond a single cont block range, causing issues.
Please fold this fixup into this patch to solve this issue. Thanks.
---
 arch/arm64/include/asm/pgtable.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index d5fbe72e820a..5e9ff16146c3 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -1823,7 +1823,7 @@ static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
 	if (likely(!pte_valid_cont(orig_pte)))
 		return __ptep_test_and_clear_young(vma, addr, ptep);
 
-	return contpte_test_and_clear_young_ptes(vma, addr, ptep, CONT_PTES);
+	return contpte_test_and_clear_young_ptes(vma, addr, ptep, 1);
 }
 
 #define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
@@ -1835,7 +1835,7 @@ static inline int ptep_clear_flush_young(struct vm_area_struct *vma,
 	if (likely(!pte_valid_cont(orig_pte)))
 		return __ptep_clear_flush_young(vma, addr, ptep);
 
-	return contpte_clear_flush_young_ptes(vma, addr, ptep, CONT_PTES);
+	return contpte_clear_flush_young_ptes(vma, addr, ptep, 1);
 }
 
 #define wrprotect_ptes wrprotect_ptes
-- 
2.47.3




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