Re: net: vrf: Handle ipv6 multicast and link-local addresses

On Wed, Aug 3, 2016 at 10:36 PM, David Ahern [off-list ref] wrote:

On 8/3/16 2:27 PM, Geert Uytterhoeven wrote:

quoted

On Wed, Aug 3, 2016 at 10:11 PM, David Ahern [off-list ref] wrote:

quoted

On 8/3/16 1:57 PM, Geert Uytterhoeven wrote:

quoted

quoted

+static void vrf_ip6_input_dst(struct sk_buff *skb, struct net_device *vrf_dev,

quoted

+                             int ifindex)
+{
+       const struct ipv6hdr *iph = ipv6_hdr(skb);
+       struct flowi6 fl6 = {
+               .daddr          = iph->daddr,
+               .saddr          = iph->saddr,
+               .flowlabel      = ip6_flowinfo(iph),

The above assignment causes the following compiler warning with
m68k-linux-gnu-gcc-4.1:

    drivers/net/vrf.c: In function ‘vrf_ip6_input_dst’:
    drivers/net/vrf.c:870: warning: initialized field with
side-effects overwritten
    drivers/net/vrf.c:870: warning: (near initialization for ‘fl6’)

Unfortunately I have no idea what it means, nor do I see what's wrong
with the code.

no idea. Fields are initialized once and left and right data types are the same.

Can you remove one line at a time? Line 870 is ".flowi6_proto   = iph->nexthdr," but all of the flowi6 macros are unique references to unique fields in flowi_common. The flowlabel line you point out is a unique field as well.

The only thing that seems to matter is assigning the result of the call to
ip6_flowinfo() to .flowlabel. Assigning a constant makes the warning go away.

No complaints for the same initialization style at line 151?

No.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds