From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756016AbcIGTK4 (ORCPT ); Wed, 7 Sep 2016 15:10:56 -0400 Received: from saturn.retrosnub.co.uk ([178.18.118.26]:41997 "EHLO saturn.retrosnub.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752970AbcIGTKy (ORCPT ); Wed, 7 Sep 2016 15:10:54 -0400 Subject: Re: [PATCH] iio: ensure ret is initialized to zero before entering do loop To: Brian Norris References: <20160905143906.13579-1-colin.king@canonical.com> <59ac3528-2245-ea61-f7e7-847bc5fe90b9@kernel.org> <20160906171008.GA1264@localhost> Cc: Colin King , Hartmut Knaack , Lars-Peter Clausen , Peter Meerwald-Stadler , linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org From: Jonathan Cameron Message-ID: Date: Wed, 7 Sep 2016 20:10:51 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.3.0 MIME-Version: 1.0 In-Reply-To: <20160906171008.GA1264@localhost> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/09/16 18:10, Brian Norris wrote: > Hi, > > On Mon, Sep 05, 2016 at 09:03:26PM +0100, Jonathan Cameron wrote: >> On 05/09/16 15:39, Colin King wrote: >>> From: Colin Ian King >>> >>> A recent fix to iio_buffer_read_first_n_outer removed ret from being set by >>> a return from wait_event_interruptible and also added a continue in a loop >>> which causes the variable ret to not be set when it reaches the end of the >>> loop. Fix this by initializing ret to zero. >>> >>> Also remove extraneous white space at the end of the loop. >>> >>> Fixes: fcf68f3c0bb2a5 ("fix sched WARNING "do not call blocking ops when !TASK_RUNNING") > > Not that it really matters, but if the commit is still going to be > amended at all, the subject was "iio: fix ...", not just "fix ...". > Definitely not important though. > >>> Signed-off-by: Colin Ian King >> Good find. Strange that got through 0-day without a warning... >> >> Cc'd Brian as author of the fix this is fixing. >> Brian can you sanity check this patch as well. > > Indeed, looks fine, and works fine: > > Tested-by: Brian Norris > Reviewed-by: Brian Norris Hi Brian, Thanks for checking this out. Unfortunately I've already applied it to fixes-togreg branch of iio.git which is strictly non rebasing so we'll have to rely on the email trace rather than git history to pick up on your tested by /reviewed by! Made me more comfortable sending the pull request to Greg though so thanks! Jonathan > > Thanks for the fix Colin, and sorry for not noticing that error :( > >> Applied to the fixes-togreg branch of iio.git and marked for stable. >> Ah well, another one for the statistics on stable patches that introduce bugs while >> fixing other bugs. >> >> Pretty unlikely this will be hit I think, but in theory you never know. >> >> Jonathan >>> --- >>> drivers/iio/industrialio-buffer.c | 4 ++-- >>> 1 file changed, 2 insertions(+), 2 deletions(-) >>> >>> diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c >>> index 49bf9c5..158aaf4 100644 >>> --- a/drivers/iio/industrialio-buffer.c >>> +++ b/drivers/iio/industrialio-buffer.c >>> @@ -110,7 +110,7 @@ ssize_t iio_buffer_read_first_n_outer(struct file *filp, char __user *buf, >>> DEFINE_WAIT_FUNC(wait, woken_wake_function); >>> size_t datum_size; >>> size_t to_wait; >>> - int ret; >>> + int ret = 0; >>> >>> if (!indio_dev->info) >>> return -ENODEV; >>> @@ -153,7 +153,7 @@ ssize_t iio_buffer_read_first_n_outer(struct file *filp, char __user *buf, >>> ret = rb->access->read_first_n(rb, n, buf); >>> if (ret == 0 && (filp->f_flags & O_NONBLOCK)) >>> ret = -EAGAIN; >>> - } while (ret == 0); >>> + } while (ret == 0); > > Personally, I avoided the temptation to fix the whitespace error in a > bugfix patch. But this does scratch my itch :) > > Brian > >>> remove_wait_queue(&rb->pollq, &wait); >>> >>> return ret; >>> >> > -- > To unsubscribe from this list: send the line "unsubscribe linux-iio" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >