From 1f4adc0a9a01b72eea5bf38fe9f6a934b2f90ce4 Mon Sep 17 00:00:00 2001
From: Claudiu Manoil <claudiu.manoil@freescale.com>
Date: Wed, 17 Jul 2013 13:40:54 +0300
Subject: gianfar: Fix illegal access when skb recycling disabled

When the skb recycling feature is disabled via module param
(gfar_skb_recycling_en), rec->local is being accessed while
not initialized.

Signed-off-by: Claudiu Manoil <claudiu.manoil@freescale.com>
Change-Id: I0f9d355302e694860cc3d46c296409126887b4a9
Reviewed-on: http://git.am.freescale.net:8181/3369
Tested-by: Review Code-CDREVIEW <CDREVIEW@freescale.com>
Reviewed-by: Fleming Andrew-AFLEMING <AFLEMING@freescale.com>

diff --git a/drivers/net/ethernet/freescale/gianfar.c b/drivers/net/ethernet/freescale/gianfar.c
index a53231c..eb60e10 100644
--- a/drivers/net/ethernet/freescale/gianfar.c
+++ b/drivers/net/ethernet/freescale/gianfar.c
@@ -1153,6 +1153,7 @@ static void gfar_init_recycle(struct gfar_private *priv)
 
 	rec->buff_size = priv->rx_buffer_size + RXBUF_ALIGNMENT;
 	skb_queue_head_init(&rec->recycle_q);
+	rec->local = NULL;
 
 	if (!gfar_skb_recycling_en)
 		goto disable_rec;
@@ -2141,6 +2142,9 @@ static void free_skb_recycle_q(struct gfar_priv_recycle *rec)
 	while ((skb = skb_dequeue(&rec->recycle_q)) != NULL)
 		dev_kfree_skb_any(skb);
 
+	if (!rec->local)
+		return;
+
 	for_each_possible_cpu(cpu) {
 		struct gfar_priv_recycle_local *local;
 
@@ -3490,6 +3494,9 @@ static struct sk_buff *gfar_new_skb(struct gfar_private *priv)
 	struct sk_buff_head *recycle_q;
 	int cpu;
 
+	if (unlikely(!rec->local))
+		goto alloc;
+
 	cpu = get_cpu();
 	local = per_cpu_ptr(rec->local, cpu);
 	skb = __skb_dequeue(&local->recycle_q);
diff --git a/drivers/net/ethernet/freescale/gianfar_sysfs.c b/drivers/net/ethernet/freescale/gianfar_sysfs.c
index 83d725b..b9c1641 100644
--- a/drivers/net/ethernet/freescale/gianfar_sysfs.c
+++ b/drivers/net/ethernet/freescale/gianfar_sysfs.c
@@ -375,6 +375,9 @@ static ssize_t gfar_show_recycle(struct device *dev,
 	for_each_possible_cpu(cpu) {
 		struct gfar_priv_recycle_local *local;
 
+		if (!rec->local)
+			break;
+
 		local = per_cpu_ptr(rec->local, cpu);
 		pr_info("local: CPU#%d: recycled skbs %d, reused skbs %d\n",
 			cpu, local->recycle_cnt, local->reuse_cnt);
-- 
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