From: Jiri Pirko <jiri@mellanox.com>
Date: Thu, 18 Jan 2018 16:14:49 +0100
Subject: net: sched: silence uninitialized parent variable warning in
 tc_dump_tfilter
Patch-mainline: v4.16-rc1
Git-commit: d680b3524cd2b9c4f1dc2ba1823c538988bb85e2
References: bsc#1109837

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>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 net/sched/cls_api.c |    7 +++++++
 1 file changed, 7 insertions(+)

--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -1317,6 +1317,13 @@ static int tc_dump_tfilter(struct sk_buf
 		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;