50 lines
		
	
	
		
			1.8 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
			
		
		
	
	
			50 lines
		
	
	
		
			1.8 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
From 54789a03adf9c924d0cf7b890323c9c1ca7ab042 Mon Sep 17 00:00:00 2001
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From: Daniel Hellstrom <daniel@gaisler.com>
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Date: Wed, 1 Dec 2010 10:26:09 +0100
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Subject: [PATCH] GRETH: fixed skb buffer memory leak on frame errors
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A new SKB buffer should not be allocated when the old SKB is reused.
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Signed-off-by: Daniel Hellstrom <daniel@gaisler.com>
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---
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 drivers/net/greth.c |   17 +++++++++++------
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 1 files changed, 11 insertions(+), 6 deletions(-)
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--- a/drivers/net/greth.c
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+++ b/drivers/net/greth.c
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@@ -879,10 +879,8 @@ static int greth_rx_gbit(struct net_devi
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 			}
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 		}
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-		/* Allocate new skb to replace current */
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-		newskb = netdev_alloc_skb(dev, MAX_FRAME_SIZE + NET_IP_ALIGN);
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-
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-		if (!bad && newskb) {
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+		/* Allocate new skb to replace current, not needed if the current skb can be reused */
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+		if (!bad && (newskb=netdev_alloc_skb(dev, MAX_FRAME_SIZE + NET_IP_ALIGN))) {
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 			skb_reserve(newskb, NET_IP_ALIGN);
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 			dma_addr = dma_map_single(greth->dev,
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@@ -919,12 +917,19 @@ static int greth_rx_gbit(struct net_devi
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 				if (net_ratelimit())
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 					dev_warn(greth->dev, "Could not create DMA mapping, dropping packet\n");
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 				dev_kfree_skb(newskb);
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-				dev->stats.rx_dropped++;
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+				dev->stats.rx_dropped++; /* reusing current skb, so it is a drop */
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 			}
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+		} else if ( bad ) {
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+			/* Bad Frame transfer, the skb is reused */
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+			dev->stats.rx_dropped++;
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 		} else {
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+			/* Failed Allocating a new skb. This is rather stupid but the current "filled" 
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+			 * skb is reused, as if transfer failure. One could argue that RX descriptor table
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+			 * handling should be divided into cleaning and filling as the TX part of the driver
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+			 */
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 			if (net_ratelimit())
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 				dev_warn(greth->dev, "Could not allocate SKB, dropping packet\n");
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-			dev->stats.rx_dropped++;
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+			dev->stats.rx_dropped++; /* reusing current skb, so it is a drop */
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 		}
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 		status = GRETH_BD_EN | GRETH_BD_IE;
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