Commit b8676b81 authored by Yicong Yang's avatar Yicong Yang Committed by JangShui Yang
Browse files

arm64: pgtable: Warn unexpected pmdp_test_and_clear_young() 

mainline inclusion
from mainline-v6.13-rc1
commit b349a5a2b6e236b25095c6ff886b3451de5ea041
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/IB4YD4
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b349a5a2b6e236b25095c6ff886b3451de5ea041



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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: default avatarYicong Yang <yangyicong@hisilicon.com>
Reviewed-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20241102104235.62560-6-yangyicong@huawei.com


Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: default avatarJiangShui Yang <yangjiangshui@h-partners.com>
parent a09a9177

arch/arm64/include/asm/pgtable.h

+2 −0
Original line number Diff line number Diff line
@@ -945,6 +945,8 @@ 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 */