[NET]: allow 32 bit socket ioctl in 64 bit kernel

Since the register_ioctl32_conversion() patch in the kernel is now obsolete,
provide another method to allow 32 bit user space ioctls to reach the kernel.

Signed-off-by: Shaun Pereira <spereira@tusc.com.au>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 21 insertions, 0 deletions

diff --git a/net/socket.c b/net/socket.c
index e3c21d5ec288..e2d5bae994de 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -107,6 +107,10 @@ static unsigned int sock_poll(struct file *file,
                               struct poll_table_struct *wait);
 static long sock_ioctl(struct file *file,
                       unsigned int cmd, unsigned long arg);
+#ifdef CONFIG_COMPAT
+static long compat_sock_ioctl(struct file *file,
+                      unsigned int cmd, unsigned long arg);
+#endif
 static int sock_fasync(int fd, struct file *filp, int on);
 static ssize_t sock_readv(struct file *file, const struct iovec *vector,
                           unsigned long count, loff_t *ppos);
@@ -128,6 +132,9 @@ static struct file_operations socket_file_ops = {
         .aio_write =    sock_aio_write,
         .poll =         sock_poll,
         .unlocked_ioctl = sock_ioctl,
+#ifdef CONFIG_COMPAT
+        .compat_ioctl = compat_sock_ioctl,
+#endif
         .mmap =         sock_mmap,
         .open =         sock_no_open,   /* special open code to disallow open via /proc */
         .release =      sock_close,
@@ -2136,6 +2143,20 @@ void socket_seq_show(struct seq_file *seq)
 }
 #endif /* CONFIG_PROC_FS */
 
+#ifdef CONFIG_COMPAT
+static long compat_sock_ioctl(struct file *file, unsigned cmd,
+                                unsigned long arg)
+{
+        struct socket *sock = file->private_data;
+        int ret = -ENOIOCTLCMD;
+
+        if (sock->ops->compat_ioctl)
+                ret = sock->ops->compat_ioctl(sock, cmd, arg);
+
+        return ret;
+}
+#endif
+
 /* ABI emulation layers need these two */
 EXPORT_SYMBOL(move_addr_to_kernel);
 EXPORT_SYMBOL(move_addr_to_user);