From: Yicong Yang <yangyicong@hisilicon.com> commit b349a5a2b6e236b25095c6ff886b3451de5ea041 upstream. 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 <yangyicong@hisilicon.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20241102104235.62560-6-yangyicong@huawei.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: JiangShui Yang <yangjiangshui@h-partners.com> Signed-off-by: Qi Xi <xiqi2@huawei.com> --- 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 3c82bae2602e..1b176f23da09 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -858,6 +858,8 @@ 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 */ -- 2.33.0