net: Add some clarification to skb_tx_timestamp() comment.

We've seen so many instances of people invoking skb_tx_timestamp() after the device already has been given the packet, that it's worth being a little bit more verbose and explicit in this comment. Signed-off-by: David S. Miller <[email protected]>
cbmeeks · Dec 27, 2013 · 73409f3 · 73409f3
1 parent 37ec274
commit 73409f3
Showing 1 changed file with 4 additions and 0 deletions.
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
@@ -2531,6 +2531,10 @@ static inline void sw_tx_timestamp(struct sk_buff *skb)
  * Ethernet MAC Drivers should call this function in their hard_xmit()
  * function immediately before giving the sk_buff to the MAC hardware.
  *
+ * Specifically, one should make absolutely sure that this function is
+ * called before TX completion of this packet can trigger.  Otherwise
+ * the packet could potentially already be freed.
+ *
  * @skb: A socket buffer.
  */
 static inline void skb_tx_timestamp(struct sk_buff *skb)