diff options
| -rw-r--r-- | net/netlink/af_netlink.c | 28 |
1 files changed, 16 insertions, 12 deletions
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index 7965ca7c461d..50889be1517d 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -594,16 +594,6 @@ netlink_current_frame(const struct netlink_ring *ring, return netlink_lookup_frame(ring, ring->head, status); } -static struct nl_mmap_hdr * -netlink_previous_frame(const struct netlink_ring *ring, - enum nl_mmap_status status) -{ - unsigned int prev; - - prev = ring->head ? ring->head - 1 : ring->frame_max; - return netlink_lookup_frame(ring, prev, status); -} - static void netlink_increment_head(struct netlink_ring *ring) { ring->head = ring->head != ring->frame_max ? ring->head + 1 : 0; @@ -624,6 +614,21 @@ static void netlink_forward_ring(struct netlink_ring *ring) } while (ring->head != head); } +static bool netlink_has_valid_frame(struct netlink_ring *ring) +{ + unsigned int head = ring->head, pos = head; + const struct nl_mmap_hdr *hdr; + + do { + hdr = __netlink_lookup_frame(ring, pos); + if (hdr->nm_status == NL_MMAP_STATUS_VALID) + return true; + pos = pos != 0 ? pos - 1 : ring->frame_max; + } while (pos != head); + + return false; +} + static bool netlink_dump_space(struct netlink_sock *nlk) { struct netlink_ring *ring = &nlk->rx_ring; @@ -671,8 +676,7 @@ static unsigned int netlink_poll(struct file *file, struct socket *sock, spin_lock_bh(&sk->sk_receive_queue.lock); if (nlk->rx_ring.pg_vec) { - netlink_forward_ring(&nlk->rx_ring); - if (!netlink_previous_frame(&nlk->rx_ring, NL_MMAP_STATUS_UNUSED)) + if (netlink_has_valid_frame(&nlk->rx_ring)) mask |= POLLIN | POLLRDNORM; } spin_unlock_bh(&sk->sk_receive_queue.lock); |