netdev - Re: [PATCH 1/3] net: macb: Fix PTP one step sync support

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Tue, 17 May 2022 22:06:03 -0700
From:   Jakub Kicinski <kuba@...nel.org>
To:     Harini Katakam <harinik@...inx.com>
Cc:     Harini Katakam <harini.katakam@...inx.com>,
        Nicolas Ferre <nicolas.ferre@...rochip.com>,
        David Miller <davem@...emloft.net>,
        Richard Cochran <richardcochran@...il.com>,
        Claudiu Beznea <claudiu.beznea@...rochip.com>,
        Paolo Abeni <pabeni@...hat.com>,
        netdev <netdev@...r.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        Michal Simek <michal.simek@...inx.com>,
        Radhey Shyam Pandey <radhey.shyam.pandey@...inx.com>
Subject: Re: [PATCH 1/3] net: macb: Fix PTP one step sync support

On Wed, 18 May 2022 09:53:29 +0530 Harini Katakam wrote:
> On Wed, May 18, 2022 at 8:12 AM Jakub Kicinski <kuba@...nel.org> wrote:
> >
> > On Tue, 17 May 2022 13:02:57 +0530 Harini Katakam wrote:  
> > > PTP one step sync packets cannot have CSUM padding and insertion in
> > > SW since time stamp is inserted on the fly by HW.
> > > In addition, ptp4l version 3.0 and above report an error when skb
> > > timestamps are reported for packets that not processed for TX TS
> > > after transmission.
> > > Add a helper to identify PTP one step sync and fix the above two
> > > errors.
> > > Also reset ptp OSS bit when one step is not selected.
> > >
> > > Fixes: ab91f0a9b5f4 ("net: macb: Add hardware PTP support")
> > > Fixes: 653e92a9175e ("net: macb: add support for padding and fcs computation")  
> >
> > Please make sure to CC authors of the patches under fixes.
> > ./scripts/get_maintainer should point them out.  
> 
> Thanks for the review.
> Rafal Ozieblo <rafalo@...ence.com> is the author of the first Fixes
> patch but that
> address hasn't worked in the last ~4 yrs.
> I have cced Claudiu and everyone else from the maintainers
> (Eric Dumazet <edumazet@...gle.com> also doesn't work)

I see, thanks, added Rafal's email to the ignore list, 
I'm quite sure Eric's email address works.

> > > @@ -1158,13 +1192,14 @@ static int macb_tx_complete(struct macb_queue *queue, int budget)
> > >
> > >                       /* First, update TX stats if needed */
> > >                       if (skb) {
> > > -                             if (unlikely(skb_shinfo(skb)->tx_flags &
> > > -                                          SKBTX_HW_TSTAMP) &&
> > > -                                 gem_ptp_do_txstamp(queue, skb, desc) == 0) {
> > > -                                     /* skb now belongs to timestamp buffer
> > > -                                      * and will be removed later
> > > -                                      */
> > > -                                     tx_skb->skb = NULL;
> > > +                             if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP) &&  
> >
> > ptp_oss already checks if HW_TSTAMP is set.  
> 
> The check for SKBTX_HW_TSTAMP is required here universally and not
> just inside ptp_oss.
> I will remove the redundant check in ptp_oss instead. Please see the
> reply below.

But then you need to add this check in the padding/fcs call site and
the place where NOCRC is set. If you wrap the check for SKBTX_HW_TSTAMP
in the helper with likely() and remove the inline - will the compiler
not split the function and inline just that check? And leave the rest
as a functionname.part... thing?