add a fix for tun/tap related crashes (backported by Carlos Sobrinho)

SVN-Revision: 5352
18 years ago · 6d531dbf84
parent ab9a7a900e
commit 6d531dbf84
1 changed files with 102 additions and 0 deletions
--- a/target/linux/generic-2.4/patches/230-tun_get_user_backport.patch
+++ b/target/linux/generic-2.4/patches/230-tun_get_user_backport.patch
@ -0,0 +1,102 @@
+--- linux-2.4.32/drivers/net/tun.c 2006-10-28 18:21:45.000000000 +0100
+++ new.linux-2.4.32/drivers/net/tun.c 2006-10-28 18:50:53.000000000 +0100
+@@ -185,22 +185,31 @@
+ {
+ 	struct tun_pi pi = { 0, __constant_htons(ETH_P_IP) };
+ 	struct sk_buff *skb;
+-	size_t len = count;
+	size_t len = count, align = 0;
+ 
+ 	if (!(tun->flags & TUN_NO_PI)) {
+ 		if ((len -= sizeof(pi)) > count)
+ 			return -EINVAL;
+ 
+-		memcpy_fromiovec((void *)&pi, iv, sizeof(pi));
+ 		if(memcpy_fromiovec((void *)&pi, iv, sizeof(pi)))
+ 			return -EFAULT;
+ 	}
+- 
+-	if (!(skb = alloc_skb(len + 2, GFP_KERNEL))) {
+
+	if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV)
+		align = NET_IP_ALIGN;
+  
+	if (!(skb = alloc_skb(len + align, GFP_KERNEL))) {
+ 		tun->stats.rx_dropped++;
+ 		return -ENOMEM;
+ 	}
+ 
+-	skb_reserve(skb, 2);
+-	memcpy_fromiovec(skb_put(skb, len), iv, len);
+	if (align)
+		skb_reserve(skb, align);
+ 	if (memcpy_fromiovec(skb_put(skb, len), iv, len)) {
+		tun->stats.rx_dropped++;
+		kfree_skb(skb);
+ 		return -EFAULT;
+	}
+ 
+ 	skb->dev = &tun->dev;
+ 	switch (tun->flags & TUN_TYPE_MASK) {
+@@ -271,7 +271,8 @@
+ 			pi.flags |= TUN_PKT_STRIP;
+ 		}
+  
+-		memcpy_toiovec(iv, (void *) &pi, sizeof(pi));
+		if(memcpy_toiovec(iv, (void *) &pi, sizeof(pi)))
+			return -EFAULT;
+ 		total += sizeof(pi);
+ 	}       
+ 
+--- linux-2.4.32/include/linux/skbuff.h	2006-10-28 19:31:31.000000000 +0100
+++ new.linux-2.4.32/include/linux/skbuff.h	2006-10-28 19:29:27.000000000 +0100
+@@ -918,6 +918,49 @@
+ 	skb->tail+=len;
+ }
+ 
+/*
+ * CPUs often take a performance hit when accessing unaligned memory
+ * locations. The actual performance hit varies, it can be small if the
+ * hardware handles it or large if we have to take an exception and fix it
+ * in software.
+ *
+ * Since an ethernet header is 14 bytes network drivers often end up with
+ * the IP header at an unaligned offset. The IP header can be aligned by
+ * shifting the start of the packet by 2 bytes. Drivers should do this
+ * with:
+ *
+ * skb_reserve(NET_IP_ALIGN);
+ *
+ * The downside to this alignment of the IP header is that the DMA is now
+ * unaligned. On some architectures the cost of an unaligned DMA is high
+ * and this cost outweighs the gains made by aligning the IP header.
+ * 
+ * Since this trade off varies between architectures, we allow NET_IP_ALIGN
+ * to be overridden.
+ */
+#ifndef NET_IP_ALIGN
+#define NET_IP_ALIGN    2
+#endif
+
+/*
+ * The networking layer reserves some headroom in skb data (via
+ * dev_alloc_skb). This is used to avoid having to reallocate skb data when
+ * the header has to grow. In the default case, if the header has to grow
+ * 16 bytes or less we avoid the reallocation.
+ *
+ * Unfortunately this headroom changes the DMA alignment of the resulting
+ * network packet. As for NET_IP_ALIGN, this unaligned DMA is expensive
+ * on some architectures. An architecture can override this value,
+ * perhaps setting it to a cacheline in size (since that will maintain
+ * cacheline alignment of the DMA). It must be a power of 2.
+ *
+ * Various parts of the networking layer expect at least 16 bytes of
+ * headroom, you should not reduce this.
+ */
+#ifndef NET_SKB_PAD
+#define NET_SKB_PAD     16
+#endif
+ 
+ extern int ___pskb_trim(struct sk_buff *skb, unsigned int len, int realloc);
+ 
+ static inline void __skb_trim(struct sk_buff *skb, unsigned int len)