From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Grall Subject: Re: [PATCH] xen/arm: Correctly handle non-page aligned pointer in raw_copy_* Date: Tue, 18 Feb 2014 15:05:58 +0000 Message-ID: <530376D6.9000704@linaro.org> References: <1392397809-13255-1-git-send-email-julien.grall@linaro.org> <1392735576.11080.87.camel@kazak.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta3.messagelabs.com ([195.245.230.39]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1WFmFI-0001o1-TP for xen-devel@lists.xenproject.org; Tue, 18 Feb 2014 15:06:05 +0000 Received: by mail-ea0-f169.google.com with SMTP id h10so8018537eak.14 for ; Tue, 18 Feb 2014 07:06:03 -0800 (PST) In-Reply-To: <1392735576.11080.87.camel@kazak.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: xen-devel@lists.xenproject.org, tim@xen.org, george.dunlap@citrix.com, stefano.stabellini@citrix.com List-Id: xen-devel@lists.xenproject.org On 02/18/2014 02:59 PM, Ian Campbell wrote: > On Fri, 2014-02-14 at 17:10 +0000, Julien Grall wrote: >> The current implementation of raw_copy_* helpers may lead to data corruption >> and sometimes Xen crash when the guest virtual address is not aligned to >> PAGE_SIZE. > > Isn't a non-aligned address the vast majority of the cases (hypercall > arguments on the guest stack)? How have we managed to get away with this > for so long? Because most of the time the size is smaller than 1 page. It not the case with flask policy. -- Julien Grall