2 files changed, 35 insertions, 12 deletions

diff --git a/drivers/net/wireless/mwifiex/pcie.c b/drivers/net/wireless/mwifiex/pcie.c
index 574d4b59746..2cc9b6fca49 100644
--- a/drivers/net/wireless/mwifiex/pcie.c
+++ b/drivers/net/wireless/mwifiex/pcie.c
@@ -50,7 +50,7 @@ mwifiex_map_pci_memory(struct mwifiex_adapter *adapter, struct sk_buff *skb,
 		return -1;
 	}
 	mapping.len = size;
-	memcpy(skb->cb, &mapping, sizeof(mapping));
+	mwifiex_store_mapping(skb, &mapping);
 	return 0;
 }
 
@@ -60,7 +60,7 @@ static void mwifiex_unmap_pci_memory(struct mwifiex_adapter *adapter,
 	struct pcie_service_card *card = adapter->card;
 	struct mwifiex_dma_mapping mapping;
 
-	MWIFIEX_SKB_PACB(skb, &mapping);
+	mwifiex_get_mapping(skb, &mapping);
 	pci_unmap_single(card->dev, mapping.addr, mapping.len, flags);
 }
 
diff --git a/drivers/net/wireless/mwifiex/util.h b/drivers/net/wireless/mwifiex/util.h
index ddae5702139..caadb3737b9 100644
--- a/drivers/net/wireless/mwifiex/util.h
+++ b/drivers/net/wireless/mwifiex/util.h
@@ -20,32 +20,55 @@
 #ifndef _MWIFIEX_UTIL_H_
 #define _MWIFIEX_UTIL_H_
 
+struct mwifiex_dma_mapping {
+	dma_addr_t addr;
+	size_t len;
+};
+
+struct mwifiex_cb {
+	struct mwifiex_dma_mapping dma_mapping;
+	union {
+		struct mwifiex_rxinfo rx_info;
+		struct mwifiex_txinfo tx_info;
+	};
+};
+
 static inline struct mwifiex_rxinfo *MWIFIEX_SKB_RXCB(struct sk_buff *skb)
 {
-	return (struct mwifiex_rxinfo *)(skb->cb + sizeof(dma_addr_t));
+	struct mwifiex_cb *cb = (struct mwifiex_cb *)skb->cb;
+
+	BUILD_BUG_ON(sizeof(struct mwifiex_cb) > sizeof(skb->cb));
+	return &cb->rx_info;
 }
 
 static inline struct mwifiex_txinfo *MWIFIEX_SKB_TXCB(struct sk_buff *skb)
 {
-	return (struct mwifiex_txinfo *)(skb->cb + sizeof(dma_addr_t));
+	struct mwifiex_cb *cb = (struct mwifiex_cb *)skb->cb;
+
+	return &cb->tx_info;
 }
 
-struct mwifiex_dma_mapping {
-	dma_addr_t addr;
-	size_t len;
-};
+static inline void mwifiex_store_mapping(struct sk_buff *skb,
+					 struct mwifiex_dma_mapping *mapping)
+{
+	struct mwifiex_cb *cb = (struct mwifiex_cb *)skb->cb;
+
+	memcpy(&cb->dma_mapping, mapping, sizeof(*mapping));
+}
 
-static inline void MWIFIEX_SKB_PACB(struct sk_buff *skb,
-					struct mwifiex_dma_mapping *mapping)
+static inline void mwifiex_get_mapping(struct sk_buff *skb,
+				       struct mwifiex_dma_mapping *mapping)
 {
-	memcpy(mapping, skb->cb, sizeof(*mapping));
+	struct mwifiex_cb *cb = (struct mwifiex_cb *)skb->cb;
+
+	memcpy(mapping, &cb->dma_mapping, sizeof(*mapping));
 }
 
 static inline dma_addr_t MWIFIEX_SKB_DMA_ADDR(struct sk_buff *skb)
 {
 	struct mwifiex_dma_mapping mapping;
 
-	MWIFIEX_SKB_PACB(skb, &mapping);
+	mwifiex_get_mapping(skb, &mapping);
 
 	return mapping.addr;
 }