Re: [PATCH v5 03/14] KVM: ARM: Initial skeleton to compile KVM support

Russell King - ARM Linux
2013-01-16T09:45:03Z

On Wed, Jan 16, 2013 at 01:26:01PM +1030, Rusty Russell wrote:
> Christoffer Dall <c.dall@virtualopensystems.com> writes:
>
> > On Mon, Jan 14, 2013 at 11:24 AM, Russell King - ARM Linux
> > <linux@arm.linux.org.uk> wrote:
> >> On Tue, Jan 08, 2013 at 01:38:55PM -0500, Christoffer Dall wrote:
> >>> + /* -ENOENT for unknown features, -EINVAL for invalid combinations. */
> >>> + for (i = 0; i < sizeof(init->features)*8; i++) {
> >>> + if (init->features[i / 32] & (1 << (i % 32))) {
> >>
> >> Isn't this an open-coded version of test_bit() ?
> >
> > indeed, nicely spotted:
>
> BTW, I wrote it that was out of excessive paranoia: it's a userspace
> API, and test_bit() won't be right on 64 bit BE systems.

So why is this a concern for 32-bit systems (which are, by definition,
only in arch/arm) ?