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. Thanks Eric > > Thanks, > -Christoffer >
