From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934194Ab0J2RSF (ORCPT ); Fri, 29 Oct 2010 13:18:05 -0400 Received: from claw.goop.org ([74.207.240.146]:37343 "EHLO claw.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932701Ab0J2RSD (ORCPT ); Fri, 29 Oct 2010 13:18:03 -0400 Message-ID: <4CCB01C9.4020007@goop.org> Date: Fri, 29 Oct 2010 10:18:01 -0700 From: Jeremy Fitzhardinge User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.9) Gecko/20100921 Fedora/3.1.4-1.fc13 Lightning/1.0b3pre Thunderbird/3.1.4 MIME-Version: 1.0 To: Vasiliy Kulikov CC: kernel-janitors@vger.kernel.org, Jeremy Fitzhardinge , Ian Campbell , Konrad Rzeszutek Wilk , linux-kernel@vger.kernel.org, xen-devel@lists.xen.org, virtualization@lists.osdl.org Subject: Re: [PATCH] xen: xenfs: privcmd: check put_user() return code References: <1288265942-12581-1-git-send-email-segooon@gmail.com> In-Reply-To: <1288265942-12581-1-git-send-email-segooon@gmail.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/28/2010 04:39 AM, Vasiliy Kulikov wrote: > put_user() may fail. In this case propagate error code from > privcmd_ioctl_mmap_batch(). Thanks for looking at this. I'm in two minds about this; the existing logic is such that these put_users can only fail if something else has already failed and its returning an error. I guess it would be useful to get an EFAULT if you've got a problem writing back the results. IanC, any opinion? Thanks, J > Signed-off-by: Vasiliy Kulikov > --- > Compile tested. > > drivers/xen/xenfs/privcmd.c | 8 ++------ > 1 files changed, 2 insertions(+), 6 deletions(-) > > diff --git a/drivers/xen/xenfs/privcmd.c b/drivers/xen/xenfs/privcmd.c > index f80be7f..2eb04c8 100644 > --- a/drivers/xen/xenfs/privcmd.c > +++ b/drivers/xen/xenfs/privcmd.c > @@ -266,9 +266,7 @@ static int mmap_return_errors(void *data, void *state) > xen_pfn_t *mfnp = data; > struct mmap_batch_state *st = state; > > - put_user(*mfnp, st->user++); > - > - return 0; > + return put_user(*mfnp, st->user++); > } > > static struct vm_operations_struct privcmd_vm_ops; > @@ -323,10 +321,8 @@ static long privcmd_ioctl_mmap_batch(void __user *udata) > up_write(&mm->mmap_sem); > > if (state.err > 0) { > - ret = 0; > - > state.user = m.arr; > - traverse_pages(m.num, sizeof(xen_pfn_t), > + ret = traverse_pages(m.num, sizeof(xen_pfn_t), > &pagelist, > mmap_return_errors, &state); > }