From 506f0e09ce36477ac610b6e9b52cbd4d5ead0c01 Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Sat, 11 May 2019 23:14:46 +0300 Subject: [PATCH] net: dsa: Remove dangerous DSA_SKB_CLONE() macro This does not cause any bug now because it has no users, but its body contains two pointer definitions within a code block: struct sk_buff *clone = _clone; \ struct sk_buff *skb = _skb; \ When calling the macro as DSA_SKB_CLONE(clone, skb), these variables would obscure the arguments that the macro was called with, and the initializers would be a no-op instead of doing their job (undefined behavior, by the way, but GCC nicely puts NULL pointers instead). So simply remove this broken macro and leave users to simply call "DSA_SKB_CB(skb)->clone = clone" by hand when needed. There is one functional difference when doing what I just suggested above: the control block won't be transferred from the original skb into the clone. Since there's no foreseen need for the control block in the clone ATM, this is ok. Fixes: b68b0dd0fb2d ("net: dsa: Keep private info in the skb->cb") Signed-off-by: Vladimir Oltean Reviewed-by: Andrew Lunn Signed-off-by: David S. Miller --- include/net/dsa.h | 9 --------- 1 file changed, 9 deletions(-) diff --git a/include/net/dsa.h b/include/net/dsa.h index 35ca1f2c6e28..1f6b8608b0b7 100644 --- a/include/net/dsa.h +++ b/include/net/dsa.h @@ -105,15 +105,6 @@ struct __dsa_skb_cb { #define DSA_SKB_CB_PRIV(skb) \ ((void *)(skb)->cb + offsetof(struct __dsa_skb_cb, priv)) -#define DSA_SKB_CB_CLONE(_clone, _skb) \ - { \ - struct sk_buff *clone = _clone; \ - struct sk_buff *skb = _skb; \ - \ - DSA_SKB_CB_COPY(clone, skb); \ - DSA_SKB_CB(skb)->clone = clone; \ - } - struct dsa_switch_tree { struct list_head list;