2 files changed, 55 insertions, 1 deletions

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index a4664cc68e2b..09d262415769 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1066,6 +1066,7 @@ struct net_device {
 #define NETIF_F_NTUPLE          (1 << 27) /* N-tuple filters supported */
 #define NETIF_F_RXHASH          (1 << 28) /* Receive hashing offload */
 #define NETIF_F_RXCSUM          (1 << 29) /* Receive checksumming offload */
+#define NETIF_F_NOCACHE_COPY    (1 << 30) /* Use no-cache copyfromuser */
 
         /* Segmentation offload features */
 #define NETIF_F_GSO_SHIFT       16
@@ -1081,7 +1082,7 @@ struct net_device {
         /* = all defined minus driver/device-class-related */
 #define NETIF_F_NEVER_CHANGE    (NETIF_F_HIGHDMA | NETIF_F_VLAN_CHALLENGED | \
                                   NETIF_F_LLTX | NETIF_F_NETNS_LOCAL)
-#define NETIF_F_ETHTOOL_BITS    (0x3f3fffff & ~NETIF_F_NEVER_CHANGE)
+#define NETIF_F_ETHTOOL_BITS    (0x7f3fffff & ~NETIF_F_NEVER_CHANGE)
 
         /* List of features with software fallbacks. */
 #define NETIF_F_GSO_SOFTWARE    (NETIF_F_TSO | NETIF_F_TSO_ECN | \
diff --git a/include/net/sock.h b/include/net/sock.h
index da0534d3401c..43bd515e92fd 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -52,6 +52,7 @@
 #include <linux/mm.h>
 #include <linux/security.h>
 #include <linux/slab.h>
+#include <linux/uaccess.h>
 
 #include <linux/filter.h>
 #include <linux/rculist_nulls.h>
@@ -1389,6 +1390,58 @@ static inline void sk_nocaps_add(struct sock *sk, int flags)
         sk->sk_route_caps &= ~flags;
 }
 
+static inline int skb_do_copy_data_nocache(struct sock *sk, struct sk_buff *skb,
+                                           char __user *from, char *to,
+                                           int copy)
+{
+        if (skb->ip_summed == CHECKSUM_NONE) {
+                int err = 0;
+                __wsum csum = csum_and_copy_from_user(from, to, copy, 0, &err);
+                if (err)
+                        return err;
+                skb->csum = csum_block_add(skb->csum, csum, skb->len);
+        } else if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) {
+                if (!access_ok(VERIFY_READ, from, copy) ||
+                    __copy_from_user_nocache(to, from, copy))
+                        return -EFAULT;
+        } else if (copy_from_user(to, from, copy))
+                return -EFAULT;
+
+        return 0;
+}
+
+static inline int skb_add_data_nocache(struct sock *sk, struct sk_buff *skb,
+                                       char __user *from, int copy)
+{
+        int err;
+
+        err = skb_do_copy_data_nocache(sk, skb, from, skb_put(skb, copy), copy);
+        if (err)
+                __skb_trim(skb, skb->len);
+
+        return err;
+}
+
+static inline int skb_copy_to_page_nocache(struct sock *sk, char __user *from,
+                                           struct sk_buff *skb,
+                                           struct page *page,
+                                           int off, int copy)
+{
+        int err;
+
+        err = skb_do_copy_data_nocache(sk, skb, from,
+                                       page_address(page) + off, copy);
+        if (err)
+                return err;
+
+        skb->len             += copy;
+        skb->data_len        += copy;
+        skb->truesize        += copy;
+        sk->sk_wmem_queued   += copy;
+        sk_mem_charge(sk, copy);
+        return 0;
+}
+
 static inline int skb_copy_to_page(struct sock *sk, char __user *from,
                                    struct sk_buff *skb, struct page *page,
                                    int off, int copy)