Re: [PATCH 30/31] x86, pkeys: create an x86 arch_calc_vm_prot_bits() for VMA flags

From: Thomas Gleixner
Date: Fri Jan 08 2016 - 14:41:29 EST


On Wed, 6 Jan 2016, Dave Hansen wrote:

>
> From: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
>
> calc_vm_prot_bits() takes PROT_{READ,WRITE,EXECUTE} bits and
> turns them in to the vma->vm_flags/VM_* bits. We need to do a
> similar thing for protection keys.
>
> We take a protection key (4 bits) and encode it in to the 4
> VM_PKEY_* bits.
>
> Note: this code is not new. It was simply a part of the
> mprotect_pkey() patch in the past. I broke it out for use
> in the execute-only support.
>
> Signed-off-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>

Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>