1 files changed, 41 insertions, 9 deletions

diff --git a/net/socket.c b/net/socket.c
index 3ca2fd9e3720..ccc576a6a508 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -156,7 +156,7 @@ static const struct file_operations socket_file_ops = {
  */
 
 static DEFINE_SPINLOCK(net_family_lock);
-static const struct net_proto_family *net_families[NPROTO] __read_mostly;
+static const struct net_proto_family __rcu *net_families[NPROTO] __read_mostly;
 
 /*
  *      Statistics counters of the socket lists
@@ -262,6 +262,7 @@ static struct inode *sock_alloc_inode(struct super_block *sb)
 }
 
 
+
 static void wq_free_rcu(struct rcu_head *head)
 {
         struct socket_wq *wq = container_of(head, struct socket_wq, rcu);
@@ -360,14 +361,14 @@ static int sock_alloc_file(struct socket *sock, struct file **f, int flags)
         if (unlikely(fd < 0))
                 return fd;
 
-        path.dentry = d_alloc(sock_mnt->mnt_sb->s_root, &name);
+        path.dentry = d_alloc_pseudo(sock_mnt->mnt_sb, &name);
         if (unlikely(!path.dentry)) {
                 put_unused_fd(fd);
                 return -ENOMEM;
         }
         path.mnt = mntget(sock_mnt);
 
-        path.dentry->d_op = &sockfs_dentry_operations;
+        d_set_d_op(path.dentry, &sockfs_dentry_operations);
         d_instantiate(path.dentry, SOCK_INODE(sock));
         SOCK_INODE(sock)->i_fop = &socket_file_ops;
 
@@ -732,6 +733,21 @@ static int sock_recvmsg_nosec(struct socket *sock, struct msghdr *msg,
         return ret;
 }
 
+/**
+ * kernel_recvmsg - Receive a message from a socket (kernel space)
+ * @sock:       The socket to receive the message from
+ * @msg:        Received message
+ * @vec:        Input s/g array for message data
+ * @num:        Size of input s/g array
+ * @size:       Number of bytes to read
+ * @flags:      Message flags (MSG_DONTWAIT, etc...)
+ *
+ * On return the msg structure contains the scatter/gather array passed in the
+ * vec argument. The array is modified so that it consists of the unfilled
+ * portion of the original array.
+ *
+ * The returned value is the total number of bytes received, or an error.
+ */
 int kernel_recvmsg(struct socket *sock, struct msghdr *msg,
                    struct kvec *vec, size_t num, size_t size, int flags)
 {
@@ -1200,7 +1216,7 @@ int __sock_create(struct net *net, int family, int type, int protocol,
          * requested real, full-featured networking support upon configuration.
          * Otherwise module support will break!
          */
-        if (net_families[family] == NULL)
+        if (rcu_access_pointer(net_families[family]) == NULL)
                 request_module("net-pf-%d", family);
 #endif
 
@@ -2332,10 +2348,11 @@ int sock_register(const struct net_proto_family *ops)
         }
 
         spin_lock(&net_family_lock);
-        if (net_families[ops->family])
+        if (rcu_dereference_protected(net_families[ops->family],
+                                      lockdep_is_held(&net_family_lock)))
                 err = -EEXIST;
         else {
-                net_families[ops->family] = ops;
+                rcu_assign_pointer(net_families[ops->family], ops);
                 err = 0;
         }
         spin_unlock(&net_family_lock);
@@ -2363,7 +2380,7 @@ void sock_unregister(int family)
         BUG_ON(family < 0 || family >= NPROTO);
 
         spin_lock(&net_family_lock);
-        net_families[family] = NULL;
+        rcu_assign_pointer(net_families[family], NULL);
         spin_unlock(&net_family_lock);
 
         synchronize_rcu();
@@ -2374,6 +2391,8 @@ EXPORT_SYMBOL(sock_unregister);
 
 static int __init sock_init(void)
 {
+        int err;
+
         /*
          *      Initialize sock SLAB cache.
          */
@@ -2390,8 +2409,15 @@ static int __init sock_init(void)
          */
 
         init_inodecache();
-        register_filesystem(&sock_fs_type);
+
+        err = register_filesystem(&sock_fs_type);
+        if (err)
+                goto out_fs;
         sock_mnt = kern_mount(&sock_fs_type);
+        if (IS_ERR(sock_mnt)) {
+                err = PTR_ERR(sock_mnt);
+                goto out_mount;
+        }
 
         /* The real protocol initialization is performed in later initcalls.
          */
@@ -2404,7 +2430,13 @@ static int __init sock_init(void)
         skb_timestamping_init();
 #endif
 
-        return 0;
+out:
+        return err;
+
+out_mount:
+        unregister_filesystem(&sock_fs_type);
+out_fs:
+        goto out;
 }
 
 core_initcall(sock_init);       /* early initcall */