[RFC PATCH 06/12] debug: NULL pointer check in ip_output

[Patrick Ohly <patrick.ohly@intel.com>]

Signed-off-by: Patrick Ohly <patrick.ohly@intel.com>
---
 net/ipv4/ip_output.c |   10 ++++++++--
 1 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index ed92f0b..03a6706 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -950,8 +950,14 @@ alloc_new_skb:
 			skb->ip_summed = csummode;
 			skb->csum = 0;
 			skb_reserve(skb, hh_len);
-			if (ipc->shtx.flags)
-				*skb_tx(skb) = ipc->shtx;
+			if (ipc->shtx.flags) {
+				if (skb_tx(skb)) 
+					*skb_tx(skb) = ipc->shtx;
+				else
+					printk(KERN_DEBUG
+						"ERROR: skb with flags %x and no tx ptr\n",
+						ipc->shtx.flags);
+			}
 
 			/*
 			 *	Find where to start putting bytes.
-- 
1.5.5.3