On 06/18/2020 08:01 PM, Christophe Leroy wrote:
> Fix it by using the recently added ptep_get() helper.
>
> Fixes: 9e343b467c70 ("READ_ONCE: Enforce atomicity for {READ,WRITE}_ONCE() memory accesses")
> Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
> ---
> mm/debug_vm_pgtable.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
> index e45623016aea..61ab16fb2e36 100644
> --- a/mm/debug_vm_pgtable.c
> +++ b/mm/debug_vm_pgtable.c
> @@ -246,13 +246,13 @@ static void __init pgd_populate_tests(struct mm_struct *mm, pgd_t *pgdp,
> static void __init pte_clear_tests(struct mm_struct *mm, pte_t *ptep,
> unsigned long vaddr)
> {
> - pte_t pte = READ_ONCE(*ptep);
> + pte_t pte = ptep_get(ptep);
>
> pte = __pte(pte_val(pte) | RANDOM_ORVALUE);
> set_pte_at(mm, vaddr, ptep, pte);
> barrier();
> pte_clear(mm, vaddr, ptep);
> - pte = READ_ONCE(*ptep);
> + pte = ptep_get(ptep);
> WARN_ON(!pte_none(pte));
> }
Tested this on arm64 and x86 platforms after applying the previous
series which adds ptep_get() and a follow up patch.
https://patchwork.kernel.org/project/linux-mm/list/?series=302949
https://patchwork.kernel.org/patch/11611929/
Build tested on s390 and arc platforms as well.
Reviewed-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
