Commit a080e7bd authored by Alexander Duyck's avatar Alexander Duyck Committed by David S. Miller
Browse files

net: Reserve skb headroom and set skb->dev even if using __alloc_skb 



When I had inlined __alloc_rx_skb into __netdev_alloc_skb and
__napi_alloc_skb I had overlooked the fact that there was a return in the
__alloc_rx_skb.  As a result we weren't reserving headroom or setting the
skb->dev in certain cases.  This change corrects that by adding a couple of
jump labels to jump to depending on __alloc_skb either succeeding or failing.

Fixes: 9451980a ("net: Use cached copy of pfmemalloc to avoid accessing page")
Reported-by: default avatarFelipe Balbi <balbi@ti.com>
Signed-off-by: default avatarAlexander Duyck <alexander.h.duyck@redhat.com>
Tested-by: default avatarKevin Hilman <khilman@linaro.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 59af132b

net/core/skbuff.c

+16 −4
Original line number Diff line number Diff line
@@ -414,8 +414,12 @@ struct sk_buff *__netdev_alloc_skb(struct net_device *dev, unsigned int len, 
	len += NET_SKB_PAD;



	if ((len > SKB_WITH_OVERHEAD(PAGE_SIZE)) ||

	    (gfp_mask & (__GFP_WAIT | GFP_DMA)))

		return __alloc_skb(len, gfp_mask, SKB_ALLOC_RX, NUMA_NO_NODE);

	    (gfp_mask & (__GFP_WAIT | GFP_DMA))) {

		skb = __alloc_skb(len, gfp_mask, SKB_ALLOC_RX, NUMA_NO_NODE);

		if (!skb)

			goto skb_fail;

		goto skb_success;

	}



	len += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));

	len = SKB_DATA_ALIGN(len);
@@ -445,9 +449,11 @@ struct sk_buff *__netdev_alloc_skb(struct net_device *dev, unsigned int len, 
		skb->pfmemalloc = 1;

	skb->head_frag = 1;



skb_success:

	skb_reserve(skb, NET_SKB_PAD);

	skb->dev = dev;



skb_fail:

	return skb;

}

EXPORT_SYMBOL(__netdev_alloc_skb);
@@ -475,8 +481,12 @@ struct sk_buff *__napi_alloc_skb(struct napi_struct *napi, unsigned int len, 
	len += NET_SKB_PAD + NET_IP_ALIGN;



	if ((len > SKB_WITH_OVERHEAD(PAGE_SIZE)) ||

	    (gfp_mask & (__GFP_WAIT | GFP_DMA)))

		return __alloc_skb(len, gfp_mask, SKB_ALLOC_RX, NUMA_NO_NODE);

	    (gfp_mask & (__GFP_WAIT | GFP_DMA))) {

		skb = __alloc_skb(len, gfp_mask, SKB_ALLOC_RX, NUMA_NO_NODE);

		if (!skb)

			goto skb_fail;

		goto skb_success;

	}



	len += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));

	len = SKB_DATA_ALIGN(len);
@@ -499,9 +509,11 @@ struct sk_buff *__napi_alloc_skb(struct napi_struct *napi, unsigned int len, 
		skb->pfmemalloc = 1;

	skb->head_frag = 1;



skb_success:

	skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN);

	skb->dev = napi->dev;



skb_fail:

	return skb;

}

EXPORT_SYMBOL(__napi_alloc_skb);

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