On Wed, Apr 22, 2020 at 03:25:29PM +0100, Steven Price wrote:
> diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
> index 39a372bf8afc..a4ad1b75a1a7 100644
> --- a/arch/arm64/include/asm/pgtable.h
> +++ b/arch/arm64/include/asm/pgtable.h
> @@ -80,6 +80,8 @@ extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
> #define pte_user_exec(pte) (!(pte_val(pte) & PTE_UXN))
> #define pte_cont(pte) (!!(pte_val(pte) & PTE_CONT))
> #define pte_devmap(pte) (!!(pte_val(pte) & PTE_DEVMAP))
> +#define pte_tagged(pte) (!!((pte_val(pte) & PTE_ATTRINDX_MASK) == \
> + PTE_ATTRINDX(MT_NORMAL_TAGGED)))
>
> #define pte_cont_addr_end(addr, end) \
> ({ unsigned long __boundary = ((addr) + CONT_PTE_SIZE) & CONT_PTE_MASK; \
> @@ -268,12 +270,17 @@ static inline void __check_racy_pte_update(struct mm_struct *mm, pte_t *ptep,
> __func__, pte_val(old_pte), pte_val(pte));
> }
>
> +void mte_sync_tags(pte_t *ptep, pte_t pte);
> +
> static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
> pte_t *ptep, pte_t pte)
> {
> if (pte_present(pte) && pte_user_exec(pte) && !pte_special(pte))
> __sync_icache_dcache(pte);
>
> + if (system_supports_mte() && pte_tagged(pte))
> + mte_sync_tags(ptep, pte);
I think this needs a pte_present() check as well, otherwise pte_tagged()
could match some random swap entry.
--
Catalin
