tipc: tipc clang warning

When checking the code with clang -Wsometimes-uninitialized we get the
following warning:

if (!tipc_link_is_establishing(l)) {
    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
net/tipc/node.c:847:46: note: uninitialized use occurs here
      tipc_bearer_xmit(n->net, bearer_id, &xmitq, maddr);

net/tipc/node.c:831:2: note: remove the 'if' if its condition is always
true
if (!tipc_link_is_establishing(l)) {
    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
net/tipc/node.c:821:31: note: initialize the variable 'maddr' to silence
this warning
struct tipc_media_addr *maddr;

We fix this by initializing 'maddr' to NULL. For the matter of clarity,
we also test if 'xmitq' is non-empty before we use it and 'maddr'
further down in the  function. It will never happen that 'xmitq' is non-
empty at the same time as 'maddr' is NULL, so this is a sufficient test.

Fixes: 598411d70f85 ("tipc: make resetting of links non-atomic")
Reported-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 3 deletions

diff --git a/net/tipc/node.c b/net/tipc/node.c
index 2dc4919ab23c..dd3b6dc17662 100644
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -817,10 +817,10 @@ static void __tipc_node_link_down(struct tipc_node *n, int *bearer_id,
 static void tipc_node_link_down(struct tipc_node *n, int bearer_id, bool delete)
 {
         struct tipc_link_entry *le = &n->links[bearer_id];
+        struct tipc_media_addr *maddr = NULL;
         struct tipc_link *l = le->link;
-        struct tipc_media_addr *maddr;
-        struct sk_buff_head xmitq;
         int old_bearer_id = bearer_id;
+        struct sk_buff_head xmitq;
 
         if (!l)
                 return;
@@ -844,7 +844,8 @@ static void tipc_node_link_down(struct tipc_node *n, int bearer_id, bool delete)
         tipc_node_write_unlock(n);
         if (delete)
                 tipc_mon_remove_peer(n->net, n->addr, old_bearer_id);
-        tipc_bearer_xmit(n->net, bearer_id, &xmitq, maddr);
+        if (!skb_queue_empty(&xmitq))
+                tipc_bearer_xmit(n->net, bearer_id, &xmitq, maddr);
         tipc_sk_rcv(n->net, &le->inputq);
 }