From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Grall Subject: Re: [PATCH v2] xen: arm: correctly handle continuations for 64-bit guests Date: Thu, 26 Mar 2015 11:58:20 +0000 Message-ID: <5513F45C.50609@linaro.org> References: <1427367244-419-1-git-send-email-ian.campbell@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1427367244-419-1-git-send-email-ian.campbell@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 , xen-devel@lists.xen.org Cc: tim@xen.org, stefano.stabellini@eu.citrix.com List-Id: xen-devel@lists.xenproject.org Hi Ian, On 26/03/2015 10:54, Ian Campbell wrote: > The 64-bit ABI is different to 32-bit: > > - uses x16 as the op register rather than r12. > - arguments in x0..x5 and not r0..r5. Using rN here potentially > truncates. > - return value goes in x0, not r0. > > Hypercalls can only be made directly from kernel space, so checking > the domain's size is sufficient. > > Spotted due to spurious -EFAULT when destroying a domain, due to the > hypercall's pointer argument being truncated. I'm unclear why I am > only seeing this now. > > Signed-off-by: Ian Campbell > Reviewed-by: Julien Grall > --- > I imagine this needs backporting everywhere... > > v2: Pull regs->pc update out of the conditional blocks, no need to > mess around with thumb. FWIW, with this change I confirm my Reviewed-by. Regards, -- Julien Grall