net: remove unsafe skb_insert()

I do not see how one can effectively use skb_insert() without holding
some kind of lock. Otherwise other cpus could have changed the list
right before we have a chance of acquiring list->lock.

Only existing user is in drivers/infiniband/hw/nes/nes_mgt.c and this
one probably meant to use __skb_insert() since it appears nesqp->pau_list
is protected by nesqp->pau_lock. This looks like nesqp->pau_lock
could be removed, since nesqp->pau_list.lock could be used instead.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Faisal Latif <faisal.latif@intel.com>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: linux-rdma <linux-rdma@vger.kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 0 insertions, 22 deletions

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 9a8a72cefe9b..02cd7ae3d0fb 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -2990,28 +2990,6 @@ void skb_append(struct sk_buff *old, struct sk_buff *newsk, struct sk_buff_head
 }
 EXPORT_SYMBOL(skb_append);
 
-/**
- *	skb_insert	-	insert a buffer
- *	@old: buffer to insert before
- *	@newsk: buffer to insert
- *	@list: list to use
- *
- *	Place a packet before a given packet in a list. The list locks are
- * 	taken and this function is atomic with respect to other list locked
- *	calls.
- *
- *	A buffer cannot be placed on two lists at the same time.
- */
-void skb_insert(struct sk_buff *old, struct sk_buff *newsk, struct sk_buff_head *list)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(&list->lock, flags);
-	__skb_insert(newsk, old->prev, old, list);
-	spin_unlock_irqrestore(&list->lock, flags);
-}
-EXPORT_SYMBOL(skb_insert);
-
 static inline void skb_split_inside_header(struct sk_buff *skb,
 					   struct sk_buff* skb1,
 					   const u32 len, const int pos)