From b349a5a2b6e236b25095c6ff886b3451de5ea041 Mon Sep 17 00:00:00 2001 From: Yicong Yang Date: Sat, 2 Nov 2024 18:42:35 +0800 Subject: [PATCH] arm64: pgtable: Warn unexpected pmdp_test_and_clear_young() Young bit operation on PMD table entry is only supported if FEAT_HAFT enabled system wide. Add a warning for notifying the misbehaviour. Signed-off-by: Yicong Yang Reviewed-by: Catalin Marinas Link: https://lore.kernel.org/r/20241102104235.62560-6-yangyicong@huawei.com Signed-off-by: Catalin Marinas --- arch/arm64/include/asm/pgtable.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 5182feabd943..160ca503c99f 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -1265,6 +1265,8 @@ static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma, unsigned long address, pmd_t *pmdp) { + /* Operation applies to PMD table entry only if FEAT_HAFT is enabled */ + VM_WARN_ON(pmd_table(READ_ONCE(*pmdp)) && !system_supports_haft()); return __ptep_test_and_clear_young(vma, address, (pte_t *)pmdp); } #endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG */ -- 2.25.1