Re: [PATCH] powerpc/spufs: Fix hash faults for kernel regions

["Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>]

Jeremy Kerr <jk@ozlabs.org> writes:

> Change ac29c64089b7 swapped _PAGE_USER for _PAGE_PRIVILEGED, and
> introduced check_pte_access() which denied kernel access to
> non-_PAGE_PRIVILEGED pages.
>
> However, it didn't add _PAGE_PRIVILEGED to the hash fault handler for
> spufs' kernel accesses, so the DMAs required to establish SPE memory
> no longer work.
>
> This change adds _PAGE_PRIVILEGED to the hash fault handler for
> kernel accesses.
>
> Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
> Reported-by: Sombat Tragolgosol <sombat3960@gmail.com>
> CC: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>

Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>

> ---
>  arch/powerpc/platforms/cell/spu_base.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/arch/powerpc/platforms/cell/spu_base.c b/arch/powerpc/platforms/cell/spu_base.c
> index 96c2b8a..0c45cdb 100644
> --- a/arch/powerpc/platforms/cell/spu_base.c
> +++ b/arch/powerpc/platforms/cell/spu_base.c
> @@ -197,7 +197,9 @@ static int __spu_trap_data_map(struct spu *spu, unsigned long ea, u64 dsisr)
>  	    (REGION_ID(ea) != USER_REGION_ID)) {
>
>  		spin_unlock(&spu->register_lock);
> -		ret = hash_page(ea, _PAGE_PRESENT | _PAGE_READ, 0x300, dsisr);
> +		ret = hash_page(ea,
> +				_PAGE_PRESENT | _PAGE_READ | _PAGE_PRIVILEGED,
> +				0x300, dsisr);
>  		spin_lock(&spu->register_lock);
>
>  		if (!ret) {
> -- 
> 2.7.4