diff mbox series

[v4,5/5] arm64: pgtable: Warn unexpected pmdp_test_and_clear_young()

Message ID 20241102104235.62560-6-yangyicong@huawei.com (mailing list archive)
State New
Headers show
Series Support Armv8.9/v9.4 FEAT_HAFT | expand

Commit Message

Yicong Yang Nov. 2, 2024, 10:42 a.m. UTC 
From: Yicong Yang <yangyicong@hisilicon.com>

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>
---
 arch/arm64/include/asm/pgtable.h | 2 ++
 1 file changed, 2 insertions(+)

Comments

Catalin Marinas Nov. 4, 2024, 5:29 p.m. UTC | #1 
On Sat, Nov 02, 2024 at 06:42:35PM +0800, Yicong Yang wrote:
> From: Yicong Yang <yangyicong@hisilicon.com>
> 
> 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>
diff mbox series

Patch

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 */