1 files changed, 21 insertions, 2 deletions

diff --git a/net/socket.c b/net/socket.c
index 4ca1526db756..45afa648364a 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -104,6 +104,12 @@
 #include <linux/route.h>
 #include <linux/sockios.h>
 #include <linux/atalk.h>
+#include <net/ll_poll.h>
+
+#ifdef CONFIG_NET_LL_RX_POLL
+unsigned int sysctl_net_ll_read __read_mostly;
+unsigned int sysctl_net_ll_poll __read_mostly;
+#endif
 
 static int sock_no_open(struct inode *irrelevant, struct file *dontcare);
 static ssize_t sock_aio_read(struct kiocb *iocb, const struct iovec *iov,
@@ -1142,13 +1148,24 @@ EXPORT_SYMBOL(sock_create_lite);
 /* No kernel lock held - perfect */
 static unsigned int sock_poll(struct file *file, poll_table *wait)
 {
+        unsigned int busy_flag = 0;
         struct socket *sock;
 
         /*
          *      We can't return errors to poll, so it's either yes or no.
          */
         sock = file->private_data;
-        return sock->ops->poll(file, sock, wait);
+
+        if (sk_can_busy_loop(sock->sk)) {
+                /* this socket can poll_ll so tell the system call */
+                busy_flag = POLL_BUSY_LOOP;
+
+                /* once, only if requested by syscall */
+                if (wait && (wait->_key & POLL_BUSY_LOOP))
+                        sk_busy_loop(sock->sk, 1);
+        }
+
+        return busy_flag | sock->ops->poll(file, sock, wait);
 }
 
 static int sock_mmap(struct file *file, struct vm_area_struct *vma)
@@ -2635,7 +2652,9 @@ static int __init sock_init(void)
          */
 
 #ifdef CONFIG_NETFILTER
-        netfilter_init();
+        err = netfilter_init();
+        if (err)
+                goto out;
 #endif
 
 #ifdef CONFIG_NETWORK_PHY_TIMESTAMPING