From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel De Graaf Subject: Re: [PATCH] libxc: fix xc_gntshr_munmap semantic Date: Tue, 30 Apr 2013 09:21:37 -0400 Message-ID: <517FC561.1050309@tycho.nsa.gov> References: <517A840F.7060105@invisiblethingslab.com> <20130426134535.5BA912AE@duch.mimuw.edu.pl> <1366987441.3142.128.camel@zakaz.uk.xensource.com> <517A9A06.8010004@tycho.nsa.gov> <1366990016.3142.145.camel@zakaz.uk.xensource.com> <517AA8AA.9060206@tycho.nsa.gov> <1367318396.3142.499.camel@zakaz.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1367318396.3142.499.camel@zakaz.uk.xensource.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Ian Campbell Cc: Marek Marczykowski , "xen-devel@lists.xen.org" List-Id: xen-devel@lists.xenproject.org On 04/30/2013 06:39 AM, Ian Campbell wrote: > On Fri, 2013-04-26 at 17:17 +0100, Daniel De Graaf wrote: >> On 04/26/2013 11:26 AM, Ian Campbell wrote: >>> On Fri, 2013-04-26 at 16:15 +0100, Daniel De Graaf wrote: >>>> On 04/26/2013 10:44 AM, Ian Campbell wrote: >>>>> On Fri, 2013-04-26 at 13:40 +0100, Marek Marczykowski wrote: >>>>>> "count" parameter should be pages count (as stated in comment in >>>>>> xenctrl.h), not bytes count. >>>>>> This patch fixes also the only user of this function (in xen sources) - >>>>>> libvchan. >>>>> >>>>> Looks ok to me but Daniel De Graaf wrote all this stuff, Ccing him. >>>> >>>> This also looks good to me. >>> >>> May I take that as an Ack (or a Reviewed-by if you prefer)? >> >> Yes, either one is fine. >> >> Acked-by: Daniel De Graaf > > Is the change from munmap to xc_gntshr_munmap, which wasn't mentioned in > the changelog description (tut tut), correct? It seems like these > mappings can either be establish with xc_gntshr_share_pages or with "= > ((void*)ctrl->ring) + LARGE_RING_OFFSET", with the second one being the > case I'm concerned about... Should it not duplicate the switch used at > mapping time? > > Ian. > The unmap is only done if (ctrl->read.order >= PAGE_SHIFT), which is a functional duplicate of the switch statement. However, this does bring up a different issue: the munmap() should be replaced with the correct one of xc_gntshr_munmap and xc_gnttab_munmap depending on ctrl->is_server, in the same way as ctrl->ring is unmapped. -- Daniel De Graaf National Security Agency