Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760791AbaJ3SHr (ORCPT ); Thu, 30 Oct 2014 14:07:47 -0400 Received: from p3plex2out04.prod.phx3.secureserver.net ([184.168.131.18]:36139 "EHLO p3plex2out04.prod.phx3.secureserver.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759765AbaJ3SHq convert rfc822-to-8bit (ORCPT ); Thu, 30 Oct 2014 14:07:46 -0400 From: Hartley Sweeten To: Ian Abbott , "driverdev-devel@linuxdriverproject.org" CC: Greg Kroah-Hartman , "linux-kernel@vger.kernel.org" Subject: RE: [PATCH 5/7] staging: comedi: don't allow write() on async command set up for "read" Thread-Topic: [PATCH 5/7] staging: comedi: don't allow write() on async command set up for "read" Thread-Index: AQHP9D8NeNklhsIE8UCM1SSPyB51qJxI750A Date: Thu, 30 Oct 2014 18:07:43 +0000 Message-ID: References: <1414672952-1587-1-git-send-email-abbotti@mev.co.uk> <1414672952-1587-6-git-send-email-abbotti@mev.co.uk> In-Reply-To: <1414672952-1587-6-git-send-email-abbotti@mev.co.uk> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [184.183.19.121] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thursday, October 30, 2014 5:43 AM, Ian Abbott wrote: > If a Comedi asynchronous command has been set up for data transfer in > the "read" direction on the current "write" subdevice (for those > subdevices that support both directions), don't allow the "write" file > operation as that would mess with the data in the comedi data buffer > that is written by the low-level comedi hardware driver. > > Signed-off-by: Ian Abbott > --- > drivers/staging/comedi/comedi_fops.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c > index 6805ec9..6328965 100644 > --- a/drivers/staging/comedi/comedi_fops.c > +++ b/drivers/staging/comedi/comedi_fops.c > @@ -2075,6 +2075,10 @@ static ssize_t comedi_write(struct file *file, const char __user *buf, > retval = -EACCES; > goto out; > } > + if (!(async->cmd.flags & CMDF_WRITE)) { > + retval = -EINVAL; > + goto out; > + } > > add_wait_queue(&async->wait_head, &wait); > on_wait_queue = true; > @@ -2146,6 +2150,10 @@ static ssize_t comedi_write(struct file *file, const char __user *buf, > retval = -EACCES; > break; > } > + if (!(async->cmd.flags & CMDF_WRITE)) { > + retval = -EINVAL; > + break; > + } Same question as with PATCH 4/7. Is this test needed in the while () loop. Also, are the s->busy tests needed here? > continue; > } Regards, Hartley -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/