From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx1.redhat.com ([209.132.183.28]:12343 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933954AbaFRLqQ (ORCPT ); Wed, 18 Jun 2014 07:46:16 -0400 Message-ID: <53A17C02.1080702@redhat.com> Date: Wed, 18 Jun 2014 13:46:10 +0200 From: Hans de Goede MIME-Version: 1.0 To: Antonio Ospite , linux-media@vger.kernel.org CC: Gregor Jasny Subject: Re: [PATCH RESEND] libv4lconvert: Fix a regression when converting from Y10B References: <20140603155930.f72e14f4aab39ec49bdb1b71@ao2.it> <1402930841-14755-1-git-send-email-ao2@ao2.it> <53A17B4C.3010005@redhat.com> In-Reply-To: <53A17B4C.3010005@redhat.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: Hi, On 06/18/2014 01:43 PM, Hans de Goede wrote: > Hi, > > On 06/16/2014 05:00 PM, Antonio Ospite wrote: >> Fix a regression introduced in commit >> efc29f1764a30808ebf7b3e1d9bfa27b909bf641 (libv4lconvert: Reject too >> short source buffer before accessing it). >> >> The old code: >> >> case V4L2_PIX_FMT_Y10BPACK: >> ... >> if (result == 0 && src_size < (width * height * 10 / 8)) { >> V4LCONVERT_ERR("short y10b data frame\n"); >> errno = EPIPE; >> result = -1; >> } >> ... >> >> meant to say "If the conversion was *successful* _but_ the frame size >> was invalid, then take the error path", but in >> efc29f1764a30808ebf7b3e1d9bfa27b909bf641 this (maybe weird) logic was >> misunderstood and v4lconvert_convert_pixfmt() was made to return an >> error even in the case of a successful conversion from Y10B. >> >> Fix the check, and now print only the message letting the errno and the >> result from the conversion routines to be propagated to the caller. >> >> Signed-off-by: Antonio Ospite >> Cc: Gregor Jasny > > Thanks for the patch, but: ... > >> --- >> lib/libv4lconvert/libv4lconvert.c | 5 +---- >> 1 file changed, 1 insertion(+), 4 deletions(-) >> >> diff --git a/lib/libv4lconvert/libv4lconvert.c b/lib/libv4lconvert/libv4lconvert.c >> index c49d30d..50d6906 100644 >> --- a/lib/libv4lconvert/libv4lconvert.c >> +++ b/lib/libv4lconvert/libv4lconvert.c >> @@ -1052,11 +1052,8 @@ static int v4lconvert_convert_pixfmt(struct v4lconvert_data *data, >> width, height); >> break; >> } >> - if (result == 0) { >> + if (result != 0) >> V4LCONVERT_ERR("y10b conversion failed\n"); >> - errno = EPIPE; >> - result = -1; >> - } >> break; >> >> case V4L2_PIX_FMT_RGB565: > > Why print a message here at all in the != 0 case? In the old code before commit > efc29f1764 you did not print an error when v4lconvert_y10b_to_... failed, so > I assume that that already does a V4LCONVERT_ERR in that case. So why do it a > second time with a less precise error message here? > > So I believe that the proper fix would be to just remove the entire block instead > of flipping the test and keeping the V4LCONVERT_ERR. Please send a new version > with this fixed, then I'll merge it asap. Scrap that, I decided I might just as well fix this bit myself, so I've just pushed an updated patch completely removing the second check from the V4L2_PIX_FMT_Y10BPACK case. Regards, Hans