Re: [PATCH] arm64: mm: add missing PTE_SPECIAL in pte_mkdevmap on arm64

[Will Deacon]

On Wed, Aug 07, 2019 at 12:58:51PM +0800, Jia He wrote:
> diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
> index 5fdcfe237338..e09760ece844 100644
> --- a/arch/arm64/include/asm/pgtable.h
> +++ b/arch/arm64/include/asm/pgtable.h
> @@ -209,7 +209,7 @@ static inline pmd_t pmd_mkcont(pmd_t pmd)
>  
>  static inline pte_t pte_mkdevmap(pte_t pte)
>  {
> -	return set_pte_bit(pte, __pgprot(PTE_DEVMAP));
> +	return set_pte_bit(pte, __pgprot(PTE_DEVMAP | PTE_SPECIAL));
>  }
>  
>  static inline void set_pte(pte_t *ptep, pte_t pte)
> @@ -396,7 +396,10 @@ static inline int pmd_protnone(pmd_t pmd)
>  #ifdef CONFIG_TRANSPARENT_HUGEPAGE
>  #define pmd_devmap(pmd)		pte_devmap(pmd_pte(pmd))
>  #endif
> -#define pmd_mkdevmap(pmd)	pte_pmd(pte_mkdevmap(pmd_pte(pmd)))
> +static inline pmd_t pmd_mkdevmap(pmd_t pmd)
> +{
> +	return pte_pmd(set_pte_bit(pmd_pte(pmd), __pgprot(PTE_DEVMAP)));
> +}
>  
>  #define __pmd_to_phys(pmd)	__pte_to_phys(pmd_pte(pmd))
>  #define __phys_to_pmd_val(phys)	__phys_to_pte_val(phys)

Acked-by: Will Deacon <will@xxxxxxxxxx>

I think Catalin can take this as a fix, although the commit message should
probably be trimmed down a bit to remove the two call traces etc.

Will