On Thu, Aug 06, 2026 at 09:38:44AM +0100, Muhammad Usama Anjum wrote:
> The non-MMU stub receives hw_pte_t but returns a logical pte_t
> value. Convert the stored entry through __pte_from_hw() before
> returning.
>
> Signed-off-by: Muhammad Usama Anjum <[email protected]>
> ---
> include/linux/hugetlb.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
> index bc0b9c65aa1d0..9e8b391aa4bc9 100644
> --- a/include/linux/hugetlb.h
> +++ b/include/linux/hugetlb.h
> @@ -1283,7 +1283,7 @@ static inline pte_t huge_ptep_clear_flush(struct
> vm_area_struct *vma,
> #ifdef CONFIG_MMU
> return ptep_get(ptep);
> #else
> - return *ptep;
> + return __pte_from_hw(*ptep);
But this is a direct dereferencing, which breaks the whole point, isn't it?
What about introducing something like pte_t ptep_get_sw(hw_pte_t *ptep)
to be used in exactly situations like this? With that the semantics of
hw_pte_t pointers becomes straightforward and closes the still ongoing
"storage vs lifetime" discussion:
hw_pte_t* points to HW-formatted page table entries
ptep_get() is used to obtain HW-linked/attached entries, and may wire
extra code like [1] or [2]
ptep_get_sw() is used to obtain HW-unlinked/unattached entries and in
most cases is just a direct dereference
The caller should always know whether the entry is attached or not, so
confusions like [3] are avoided.
1. https://lore.kernel.org/linux-mm/[email protected]/
2.
https://lore.kernel.org/linux-s390/[email protected]/
3.
https://lore.kernel.org/linux-s390/[email protected]/
> #endif
> }
>
> --
> 2.47.3
>
