[TG3]: Handle tg3_init_rings() failures

Handle dev_alloc_skb() failures when initializing the RX rings.
Without proper handling, the driver will crash when using a partial
ring.

Thanks to Stephane Doyon <sdoyon@max-t.com> for reporting the bug and
providing the initial patch.

Howie Xu <howie@vmware.com> also reported the same issue.

Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 27 insertions, 5 deletions

diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c
index 1253cec6ebdc..d66b06f2b865 100644
--- a/drivers/net/tg3.c
+++ b/drivers/net/tg3.c
@@ -4258,7 +4258,7 @@ static void tg3_free_rings(struct tg3 *tp)
  * end up in the driver.  tp->{tx,}lock are held and thus
  * we may not sleep.
  */
-static void tg3_init_rings(struct tg3 *tp)
+static int tg3_init_rings(struct tg3 *tp)
 {
         u32 i;
 
@@ -4307,18 +4307,38 @@ static void tg3_init_rings(struct tg3 *tp)
 
         /* Now allocate fresh SKBs for each rx ring. */
         for (i = 0; i < tp->rx_pending; i++) {
-                if (tg3_alloc_rx_skb(tp, RXD_OPAQUE_RING_STD,
-                                     -1, i) < 0)
+                if (tg3_alloc_rx_skb(tp, RXD_OPAQUE_RING_STD, -1, i) < 0) {
+                        printk(KERN_WARNING PFX
+                               "%s: Using a smaller RX standard ring, "
+                               "only %d out of %d buffers were allocated "
+                               "successfully.\n",
+                               tp->dev->name, i, tp->rx_pending);
+                        if (i == 0)
+                                return -ENOMEM;
+                        tp->rx_pending = i;
                         break;
+                }
         }
 
         if (tp->tg3_flags & TG3_FLAG_JUMBO_RING_ENABLE) {
                 for (i = 0; i < tp->rx_jumbo_pending; i++) {
                         if (tg3_alloc_rx_skb(tp, RXD_OPAQUE_RING_JUMBO,
-                                             -1, i) < 0)
+                                             -1, i) < 0) {
+                                printk(KERN_WARNING PFX
+                                       "%s: Using a smaller RX jumbo ring, "
+                                       "only %d out of %d buffers were "
+                                       "allocated successfully.\n",
+                                       tp->dev->name, i, tp->rx_jumbo_pending);
+                                if (i == 0) {
+                                        tg3_free_rings(tp);
+                                        return -ENOMEM;
+                                }
+                                tp->rx_jumbo_pending = i;
                                 break;
+                        }
                 }
         }
+        return 0;
 }
 
 /*
@@ -5969,7 +5989,9 @@ static int tg3_reset_hw(struct tg3 *tp, int reset_phy)
          * can only do this after the hardware has been
          * successfully reset.
          */
-        tg3_init_rings(tp);
+        err = tg3_init_rings(tp);
+        if (err)
+                return err;
 
         /* This value is determined during the probe time DMA
          * engine test, tg3_test_dma.