[PATCH v4 16/29] arm64: add pte_access_permitted_no_overlay()

[Anshuman Khandual]

On 5/3/24 18:31, Joey Gouly wrote:
> We do not want take POE into account when clearing the MTE tags.
> 
> Signed-off-by: Joey Gouly <joey.gouly at arm.com>
> Cc: Catalin Marinas <catalin.marinas at arm.com>
> Cc: Will Deacon <will at kernel.org>

Reviewed-by: Anshuman Khandual <anshuman.khandual at arm.com>

> ---
>  arch/arm64/include/asm/pgtable.h | 11 +++++++----
>  1 file changed, 7 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
> index 5c970a9cca67..2449e4e27ea6 100644
> --- a/arch/arm64/include/asm/pgtable.h
> +++ b/arch/arm64/include/asm/pgtable.h
> @@ -160,8 +160,10 @@ static inline pteval_t __phys_to_pte_val(phys_addr_t phys)
>   * not set) must return false. PROT_NONE mappings do not have the
>   * PTE_VALID bit set.
>   */
> -#define pte_access_permitted(pte, write) \
> +#define pte_access_permitted_no_overlay(pte, write) \
>  	(((pte_val(pte) & (PTE_VALID | PTE_USER)) == (PTE_VALID | PTE_USER)) && (!(write) || pte_write(pte)))
> +#define pte_access_permitted(pte, write) \
> +	pte_access_permitted_no_overlay(pte, write)
>  #define pmd_access_permitted(pmd, write) \
>  	(pte_access_permitted(pmd_pte(pmd), (write)))
>  #define pud_access_permitted(pud, write) \
> @@ -348,10 +350,11 @@ static inline void __sync_cache_and_tags(pte_t pte, unsigned int nr_pages)
>  	/*
>  	 * If the PTE would provide user space access to the tags associated
>  	 * with it then ensure that the MTE tags are synchronised.  Although
> -	 * pte_access_permitted() returns false for exec only mappings, they
> -	 * don't expose tags (instruction fetches don't check tags).
> +	 * pte_access_permitted_no_overlay() returns false for exec only
> +	 * mappings, they don't expose tags (instruction fetches don't check
> +	 * tags).
>  	 */
> -	if (system_supports_mte() && pte_access_permitted(pte, false) &&
> +	if (system_supports_mte() && pte_access_permitted_no_overlay(pte, false) &&
>  	    !pte_special(pte) && pte_tagged(pte))
>  		mte_sync_tags(pte, nr_pages);
>  }