From 0150539f7780d599ea73c9d897628b5b8fee7e58 Mon Sep 17 00:00:00 2001
From: Ioana Radulescu <ruxandra.radulescu@freescale.com>
Date: Wed, 28 Aug 2013 18:24:34 +0300
Subject: dpaa_eth: Fix kernel crash with timestamp support on

Recent changes in the driver moved the allocation of the skb on Rx
past the point where the timestamp/1588 code used the skb.
Reorder a bit the code to avoid NULL pointer dereferencing.

Signed-off-by: Ioana Radulescu <ruxandra.radulescu@freescale.com>
Change-Id: I09929c13bc88048be77c8678c1fb9956fec41039
Reviewed-on: http://git.am.freescale.net:8181/4443
Tested-by: Review Code-CDREVIEW <CDREVIEW@freescale.com>
Reviewed-by: Bucur Madalin-Cristian-B32716 <madalin.bucur@freescale.com>
Reviewed-by: Sovaiala Cristian-Constantin-B39531 <Cristian.Sovaiala@freescale.com>
Reviewed-by: Rivera Jose-B46482 <German.Rivera@freescale.com>

diff --git a/drivers/net/ethernet/freescale/dpa/dpaa_eth_sg.c b/drivers/net/ethernet/freescale/dpa/dpaa_eth_sg.c
index f93c346..af5a08b 100644
--- a/drivers/net/ethernet/freescale/dpa/dpaa_eth_sg.c
+++ b/drivers/net/ethernet/freescale/dpa/dpaa_eth_sg.c
@@ -265,17 +265,17 @@ static struct sk_buff *__hot contig_fd_to_skb(const struct dpa_priv_s *priv,
 
 	vaddr = phys_to_virt(addr);
 
+	/* Build the skb and adjust data and tail pointers */
+	skb = build_skb(vaddr, dpa_bp->size + DPA_SKB_TAILROOM);
+	if (unlikely(!skb))
+		return NULL;
+
 	/* do we need the timestamp for bad frames? */
 #ifdef CONFIG_FSL_DPAA_1588
 	if (priv->tsu && priv->tsu->valid && priv->tsu->hwts_rx_en_ioctl)
 		dpa_ptp_store_rxstamp(priv, skb, vaddr);
 #endif
 
-	/* Build the skb and adjust data and tail pointers */
-	skb = build_skb(vaddr, dpa_bp->size + DPA_SKB_TAILROOM);
-	if (unlikely(!skb))
-		return NULL;
-
 	/* Make sure forwarded skbs will have enough space on Tx,
 	 * if extra headers are added.
 	 */
@@ -318,15 +318,6 @@ static struct sk_buff *__hot sg_fd_to_skb(const struct dpa_priv_s *priv,
 	int *count_ptr;
 
 	vaddr = phys_to_virt(addr);
-#ifdef CONFIG_FSL_DPAA_1588
-	if (priv->tsu && priv->tsu->valid && priv->tsu->hwts_rx_en_ioctl)
-		dpa_ptp_store_rxstamp(priv, skb, vaddr);
-#endif
-
-#ifdef CONFIG_FSL_DPAA_TS
-	if (priv->ts_rx_en)
-		dpa_get_ts(priv, RX, skb_hwtstamps(skb), vaddr);
-#endif /* CONFIG_FSL_DPAA_TS */
 
 	/* Iterate through the SGT entries and add data buffers to the skb */
 	sgt = vaddr + dpa_fd_offset(fd);
@@ -360,6 +351,17 @@ static struct sk_buff *__hot sg_fd_to_skb(const struct dpa_priv_s *priv,
 				 */
 				return NULL;
 
+#ifdef CONFIG_FSL_DPAA_1588
+			if (priv->tsu && priv->tsu->valid &&
+			    priv->tsu->hwts_rx_en_ioctl)
+				dpa_ptp_store_rxstamp(priv, skb, vaddr);
+#endif
+
+#ifdef CONFIG_FSL_DPAA_TS
+			if (priv->ts_rx_en)
+				dpa_get_ts(priv, RX, skb_hwtstamps(skb), vaddr);
+#endif /* CONFIG_FSL_DPAA_TS */
+
 			dma_unmap_single(dpa_bp->dev, sg_addr, dpa_bp->size,
 				DMA_BIDIRECTIONAL);
 
-- 
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