82596: do not panic on out of memory

If dev_alloc_skb() failed then free already allocated skbs.
remove_rx_bufs() can be called multiple times, so set rbd->skb to NULL
to avoid double free. remove_rx_bufs() was moved upwards to be seen by
init_rx_bufs().

Signed-off-by: Kulikov Vasiliy <segooon@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 26 insertions, 16 deletions

diff --git a/drivers/net/82596.c b/drivers/net/82596.c
index dd8dc15556cb..73073d0b6894 100644
--- a/drivers/net/82596.c
+++ b/drivers/net/82596.c
@@ -525,7 +525,21 @@ static irqreturn_t i596_error(int irq, void *dev_id)
 }
 #endif
 
-static inline void init_rx_bufs(struct net_device *dev)
+static inline void remove_rx_bufs(struct net_device *dev)
+{
+        struct i596_private *lp = dev->ml_priv;
+        struct i596_rbd *rbd;
+        int i;
+
+        for (i = 0, rbd = lp->rbds; i < rx_ring_size; i++, rbd++) {
+                if (rbd->skb == NULL)
+                        break;
+                dev_kfree_skb(rbd->skb);
+                rbd->skb = NULL;
+        }
+}
+
+static inline int init_rx_bufs(struct net_device *dev)
 {
         struct i596_private *lp = dev->ml_priv;
         int i;
@@ -537,8 +551,11 @@ static inline void init_rx_bufs(struct net_device *dev)
         for (i = 0, rbd = lp->rbds; i < rx_ring_size; i++, rbd++) {
                 struct sk_buff *skb = dev_alloc_skb(PKT_BUF_SZ);
 
-                if (skb == NULL)
-                        panic("82596: alloc_skb() failed");
+                if (skb == NULL) {
+                        remove_rx_bufs(dev);
+                        return -ENOMEM;
+                }
+
                 skb->dev = dev;
                 rbd->v_next = rbd+1;
                 rbd->b_next = WSWAPrbd(virt_to_bus(rbd+1));
@@ -574,19 +591,8 @@ static inline void init_rx_bufs(struct net_device *dev)
         rfd->v_next = lp->rfds;
         rfd->b_next = WSWAPrfd(virt_to_bus(lp->rfds));
         rfd->cmd = CMD_EOL|CMD_FLEX;
-}
-
-static inline void remove_rx_bufs(struct net_device *dev)
-{
-        struct i596_private *lp = dev->ml_priv;
-        struct i596_rbd *rbd;
-        int i;
 
-        for (i = 0, rbd = lp->rbds; i < rx_ring_size; i++, rbd++) {
-                if (rbd->skb == NULL)
-                        break;
-                dev_kfree_skb(rbd->skb);
-        }
+        return 0;
 }
 
 
@@ -1013,7 +1019,11 @@ static int i596_open(struct net_device *dev)
                         return -EAGAIN;
         }
 #endif
-        init_rx_bufs(dev);
+        res = init_rx_bufs(dev);
+        if (res) {
+                free_irq(dev->irq, dev);
+                return res;
+        }
 
         netif_start_queue(dev);