Re: linux-next: build warning after merge of the net-next tree

From: Stephen Rothwell
Date: Wed Dec 19 2018 - 00:37:21 EST


Hi Gustavo,

On Tue, 18 Dec 2018 21:07:06 -0600 "Gustavo A. R. Silva" <gustavo@xxxxxxxxxxxxxx> wrote:
>
> On 12/18/18 8:42 PM, Stephen Rothwell wrote:
> > Hi all,
> >
> > On Thu, 29 Nov 2018 11:24:28 +1100 Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> wrote:
> >>
> >> After merging the net-next tree, today's linux-next build
> >> (x86_64_allmodconfig) produced this warning:
> >>
> >> drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c: In function 'run_xdp':
> >> drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c:324:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
> >> bpf_warn_invalid_xdp_action(xdp_act);
> >> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> >> drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c:325:2: note: here
> >> case XDP_ABORTED:
> >> ^~~~
> >> drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c:326:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
> >> trace_xdp_exception(priv->net_dev, xdp_prog, xdp_act);
> >> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> >> drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c:327:2: note: here
> >> case XDP_DROP:
> >> ^~~~
> >>
> >> Introduced by commit
> >>
> >> 7e273a8ebdd3 ("dpaa2-eth: Add basic XDP support")
> >>
> >> This due to my use of -Wimplicit-fallthrough. This is new code. The
> >> warning can be suppressed by adding a comment like /* fall through */
> >> at the appropriate places to indicate that the fallthrough is intended.
> >
> > I am still seeing these warnings.
> >
>
> That's weird. I don't see them anymore in next-20181218.
>
> They were fixed by this commit: c1cb11bcbd09f5f027cbc7fadddab169714948df

My mistake (patter mismatch :-)), there are very similar warnings in
drivers/net/veth.c which are older. Someone could fix those if they
wanted to :-)

drivers/net/veth.c: In function 'veth_xdp_rcv_one':
drivers/net/veth.c:542:4: warning: this statement may fall through [-Wimplicit-fallthrough=]
bpf_warn_invalid_xdp_action(act);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/net/veth.c:543:3: note: here
case XDP_ABORTED:
^~~~
drivers/net/veth.c: In function 'veth_xdp_rcv_skb':
drivers/net/veth.c:663:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
bpf_warn_invalid_xdp_action(act);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/net/veth.c:664:2: note: here
case XDP_ABORTED:
^~~~

--
Cheers,
Stephen Rothwell

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