net: sched: silence uninitialized parent variable warning in tc_dump_tfilter

When tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK, parent is still passed
down but the value is never used. Compiler does not recognize it and
issues a warning. Silence it down initializing parent to 0.

Fixes: 7960d1daf278 ("net: sched: use block index as a handle instead of qdisc when block is shared")
Reported-by: David Miller <davem@davemloft.net>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index e500d11da9cd5a84d89ab8f6c2b1d0d593651448..86d6e9d2cf004bb0097139093208bbba5ed361a9 100644 (file)
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -1317,6 +1317,13 @@ static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
                block = tcf_block_lookup(net, tcm->tcm_block_index);
                if (!block)
                        goto out;
+               /* If we work with block index, q is NULL and parent value
+                * will never be used in the following code. The check
+                * in tcf_fill_node prevents it. However, compiler does not
+                * see that far, so set parent to zero to silence the warning
+                * about parent being uninitialized.
+                */
+               parent = 0;
        } else {
                const struct Qdisc_class_ops *cops;
                struct net_device *dev;