gro: Fix legacy path napi_complete crash

On the legacy netif_rx path, I incorrectly tried to optimise
the napi_complete call by using __napi_complete before we reenable
IRQs.  This simply doesn't work since we need to flush the held
GRO packets first.

This patch fixes it by doing the obvious thing of reenabling
IRQs first and then calling napi_complete.

Reported-by: Frank Blaschka <blaschka@linux.vnet.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/core/dev.c b/net/core/dev.c
index f1129706ce7b3589bec1a2cbacb63fa80bdceb29..2565f6d1d66198abff8a73c7097f19b09e908cc8 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2588,9 +2588,9 @@ static int process_backlog(struct napi_struct *napi, int quota)
                local_irq_disable();
                skb = __skb_dequeue(&queue->input_pkt_queue);
                if (!skb) {
-                       __napi_complete(napi);
                        local_irq_enable();
-                       break;
+                       napi_complete(napi);
+                       goto out;
                }
                local_irq_enable();
 
@@ -2599,6 +2599,7 @@ static int process_backlog(struct napi_struct *napi, int quota)
 
        napi_gro_flush(napi);
 
+out:
        return work;
 }