From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Cooper Subject: Re: [PATCH v2 24/30] tools/libxc: Modify bitmap operations to take void pointers Date: Wed, 10 Feb 2016 10:07:12 +0000 Message-ID: <56BB0BD0.6020009@citrix.com> References: <1454679743-18133-1-git-send-email-andrew.cooper3@citrix.com> <1454679743-18133-25-git-send-email-andrew.cooper3@citrix.com> <20160208162304.GA99992@deinos.phlegethon.org> <1454949407.17191.17.camel@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1454949407.17191.17.camel@citrix.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 , Tim Deegan Cc: Wei Liu , Ian Jackson , Xen-devel List-Id: xen-devel@lists.xenproject.org On 08/02/16 16:36, Ian Campbell wrote: > On Mon, 2016-02-08 at 16:23 +0000, Tim Deegan wrote: >> At 13:42 +0000 on 05 Feb (1454679737), Andrew Cooper wrote: >>> The type of the pointer to a bitmap is not interesting; it does not >>> affect the >>> representation of the block of bits being pointed to. >> It does affect the alignment, though. Is this safe on ARM? > Good point. These constructs in the patch: > > + const unsigned long *addr = _addr; > > Would be broken if _addr were not suitably aligned for an unsigned long. > > That probably rules out this approach unfortunately. What about reworking libxc bitops in terms of unsigned char? That should cover all alignment issues. ~Andrew