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authorFelix Fietkau <nbd@openwrt.org>2006-10-31 00:57:13 +0000
committerFelix Fietkau <nbd@openwrt.org>2006-10-31 00:57:13 +0000
commit6d531dbf84fb891726a24b9067397b8a425ff418 (patch)
treedc25381c58ff91a02eb54fe9a6ef7372e30c8d1e /target/linux/generic-2.4
parentab9a7a900e1af3d0ed7777f792c3ce9c159bba1c (diff)
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add a fix for tun/tap related crashes (backported by Carlos Sobrinho)
SVN-Revision: 5352
Diffstat (limited to 'target/linux/generic-2.4')
-rw-r--r--target/linux/generic-2.4/patches/230-tun_get_user_backport.patch102
1 files changed, 102 insertions, 0 deletions
diff --git 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
new file mode 100644
index 0000000000..636ffec11d
--- /dev/null
+++ 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)