On Sat, Oct 14, 2017 at 10:53:01AM +0200, Auger Eric wrote: > Hi Christoffer, > > On 13/10/2017 19:54, Christoffer Dall wrote: > > On Fri, Oct 13, 2017 at 01:54:34PM +0200, Auger Eric wrote: > >> Hi Christoffer, > >> On 13/10/2017 13:44, Christoffer Dall wrote: > >>> On Fri, Oct 06, 2017 at 05:29:02PM +0200, Auger Eric wrote: > >>>> Hi, > >>>> > >>>> On 06/10/2017 16:37, Andre Przywara wrote: > >>>>> Hi, > >>>>> > >>>>> On 27/09/17 14:28, Eric Auger wrote: > >>>>>> If the GITS_CBASER Size field is 0, which can correspond to a > >>>>>> reset value, the userspace fails to set the GITS_CREADR/CWRITER > >>>>>> offsets to 0. This failure is not justified. > >>>>>> > >>>>>> Let's allow this setting which can also correspond to a reset value. > >>>>> > >>>>> But the GITS_CBASER size field has a +1 encoding, so can never be 0, if > >>>>> I understand the manual (and ITS_CMD_BUFFER_SIZE) correctly. > >>>> Oh OK, you're. I missed that. I would have sworn I've seen that failure > >>>> but I must have misinterpreted it. > >>>> > >>> > >>> What is CWRITER is written to a brand new ITS before the CBASER is > >>> written? > >>> > >>> I don't see us initializing the cbaser field anywhere? > >> in vgic_its_create() its is allocated with kzalloc so its->cbaser is > >> initialized at this moment. > >> > > > > Right, so it can be 0, and we still need your patch, contrary to Andre's > > comment. Am I missing something? > > No Andre is right, cbaser = 0 but ITS_CMD_BUFFER_SIZE(its->cbaser) > returns 4kB. > > #define ITS_CMD_BUFFER_SIZE(baser) ((((baser) & 0xff) + 1) << 12) > > So the check doesn't fail. > Duh, I didn't check the macro and thought it just applied a mask and shift. Thanks, -Christoffer
