netdev - Re: [PATCH net-next 2/2] dpaa2-eth: fix return codes used in ndo_setup

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]

Message-ID: <20200423123356.523264b4@hermes.lan>
Date:   Thu, 23 Apr 2020 12:33:56 -0700
From:   Stephen Hemminger <stephen@...workplumber.org>
To:     Jesper Dangaard Brouer <brouer@...hat.com>
Cc:     netdev@...r.kernel.org,
        Ilias Apalodimas <ilias.apalodimas@...aro.org>,
        Toke Høiland-Jørgensen <toke@...hat.com>,
        ruxandra.radulescu@....com, ioana.ciornei@....com,
        nipun.gupta@....com, shawnguo@...nel.org
Subject: Re: [PATCH net-next 2/2] dpaa2-eth: fix return codes used in
 ndo_setup_tc

On Thu, 23 Apr 2020 17:38:04 +0200
Jesper Dangaard Brouer <brouer@...hat.com> wrote:

> On Thu, 23 Apr 2020 08:28:58 -0700
> Stephen Hemminger <stephen@...workplumber.org> wrote:
> 
> > On Thu, 23 Apr 2020 16:57:50 +0200
> > Jesper Dangaard Brouer <brouer@...hat.com> wrote:
> >   
> > > Drivers ndo_setup_tc call should return -EOPNOTSUPP, when it cannot
> > > support the qdisc type. Other return values will result in failing the
> > > qdisc setup.  This lead to qdisc noop getting assigned, which will
> > > drop all TX packets on the interface.
> > > 
> > > Fixes: ab1e6de2bd49 ("dpaa2-eth: Add mqprio support")
> > > Signed-off-by: Jesper Dangaard Brouer <brouer@...hat.com>    
> > 
> > Would it be possible to use extack as well?  
> 
> That is what patch 1/2 already does.
> 
> > Putting errors in dmesg is unhelpful  
> 
> This patchset does not introduce any dmesg printk.
> 

I was thinking that this  
	if (num_tc  > dpaa2_eth_tc_count(priv)) {
 		netdev_err(net_dev, "Max %d traffic classes supported\n",
 			   dpaa2_eth_tc_count(priv));
-		return -EINVAL;
+		return -EOPNOTSUPP;
 	}

could be an extack message, but doing that would require a change
to the ndo_setup_tc hook to allow driver to return its own error message
as to why the setup failed.