net: ipv4: provide __rcu annotation for ifa_list

ifa_list is protected by rcu, yet code doesn't reflect this.

Add the __rcu annotations and fix up all places that are now reported by
sparse.

I've done this in the same commit to not add intermediate patches that
result in new warnings.

Reported-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

9 files changed, 49 insertions, 23 deletions

diff --git a/drivers/infiniband/hw/i40iw/i40iw_utils.c b/drivers/infiniband/hw/i40iw/i40iw_utils.c
index 337410f40860..016524683e17 100644
--- a/drivers/infiniband/hw/i40iw/i40iw_utils.c
+++ b/drivers/infiniband/hw/i40iw/i40iw_utils.c
@@ -174,10 +174,14 @@ int i40iw_inetaddr_event(struct notifier_block *notifier,
 		rcu_read_lock();
 		in = __in_dev_get_rcu(upper_dev);
 
-		if (!in->ifa_list)
-			local_ipaddr = 0;
-		else
-			local_ipaddr = ntohl(in->ifa_list->ifa_address);
+		local_ipaddr = 0;
+		if (in) {
+			struct in_ifaddr *ifa;
+
+			ifa = rcu_dereference(in->ifa_list);
+			if (ifa)
+				local_ipaddr = ntohl(ifa->ifa_address);
+		}
 
 		rcu_read_unlock();
 	} else {
diff --git a/drivers/infiniband/hw/nes/nes.c b/drivers/infiniband/hw/nes/nes.c
index e00add6d78ec..29b324726ea6 100644
--- a/drivers/infiniband/hw/nes/nes.c
+++ b/drivers/infiniband/hw/nes/nes.c
@@ -183,7 +183,13 @@ static int nes_inetaddr_event(struct notifier_block *notifier,
 
 						rcu_read_lock();
 						in = __in_dev_get_rcu(upper_dev);
-						nesvnic->local_ipaddr = in->ifa_list->ifa_address;
+						if (in) {
+							struct in_ifaddr *ifa;
+
+							ifa = rcu_dereference(in->ifa_list);
+							if (ifa)
+								nesvnic->local_ipaddr = ifa->ifa_address;
+						}
 						rcu_read_unlock();
 					} else {
 						nesvnic->local_ipaddr = ifa->ifa_address;
diff --git a/drivers/infiniband/hw/usnic/usnic_ib_main.c b/drivers/infiniband/hw/usnic/usnic_ib_main.c
index d88d9f8a7f9a..34c1f9d6c915 100644
--- a/drivers/infiniband/hw/usnic/usnic_ib_main.c
+++ b/drivers/infiniband/hw/usnic/usnic_ib_main.c
@@ -427,11 +427,16 @@ static void *usnic_ib_device_add(struct pci_dev *dev)
 	if (netif_carrier_ok(us_ibdev->netdev))
 		usnic_fwd_carrier_up(us_ibdev->ufdev);
 
-	ind = in_dev_get(netdev);
-	if (ind->ifa_list)
-		usnic_fwd_add_ipaddr(us_ibdev->ufdev,
-				     ind->ifa_list->ifa_address);
-	in_dev_put(ind);
+	rcu_read_lock();
+	ind = __in_dev_get_rcu(netdev);
+	if (ind) {
+		const struct in_ifaddr *ifa;
+
+		ifa = rcu_dereference(ind->ifa_list);
+		if (ifa)
+			usnic_fwd_add_ipaddr(us_ibdev->ufdev, ifa->ifa_address);
+	}
+	rcu_read_unlock();
 
 	usnic_mac_ip_to_gid(us_ibdev->netdev->perm_addr,
 				us_ibdev->ufdev->inaddr, &gid.raw[0]);
diff --git a/drivers/net/ethernet/via/via-velocity.h b/drivers/net/ethernet/via/via-velocity.h
index c0ecc6c7b5e0..cdfe7809e3c1 100644
--- a/drivers/net/ethernet/via/via-velocity.h
+++ b/drivers/net/ethernet/via/via-velocity.h
@@ -1509,7 +1509,7 @@ static inline int velocity_get_ip(struct velocity_info *vptr)
 	rcu_read_lock();
 	in_dev = __in_dev_get_rcu(vptr->netdev);
 	if (in_dev != NULL) {
-		ifa = (struct in_ifaddr *) in_dev->ifa_list;
+		ifa = rcu_dereference(in_dev->ifa_list);
 		if (ifa != NULL) {
 			memcpy(vptr->ip_addr, &ifa->ifa_address, 4);
 			res = 0;
diff --git a/drivers/net/plip/plip.c b/drivers/net/plip/plip.c
index feb92ecd1880..3e3ac2e496a1 100644
--- a/drivers/net/plip/plip.c
+++ b/drivers/net/plip/plip.c
@@ -1012,7 +1012,7 @@ plip_rewrite_address(const struct net_device *dev, struct ethhdr *eth)
 	in_dev = __in_dev_get_rcu(dev);
 	if (in_dev) {
 		/* Any address will do - we take the first */
-		const struct in_ifaddr *ifa = in_dev->ifa_list;
+		const struct in_ifaddr *ifa = rcu_dereference(in_dev->ifa_list);
 		if (ifa) {
 			memcpy(eth->h_source, dev->dev_addr, ETH_ALEN);
 			memset(eth->h_dest, 0xfc, 2);
@@ -1107,7 +1107,7 @@ plip_open(struct net_device *dev)
 		/* Any address will do - we take the first. We already
 		   have the first two bytes filled with 0xfc, from
 		   plip_init_dev(). */
-		struct in_ifaddr *ifa=in_dev->ifa_list;
+		const struct in_ifaddr *ifa = rcu_dereference(in_dev->ifa_list);
 		if (ifa != NULL) {
 			memcpy(dev->dev_addr+2, &ifa->ifa_local, 4);
 		}
diff --git a/drivers/net/vmxnet3/vmxnet3_drv.c b/drivers/net/vmxnet3/vmxnet3_drv.c
index 89984fcab01e..1b2a18ea855c 100644
--- a/drivers/net/vmxnet3/vmxnet3_drv.c
+++ b/drivers/net/vmxnet3/vmxnet3_drv.c
@@ -3651,13 +3651,19 @@ vmxnet3_suspend(struct device *device)
 	}
 
 	if (adapter->wol & WAKE_ARP) {
-		in_dev = in_dev_get(netdev);
-		if (!in_dev)
+		rcu_read_lock();
+
+		in_dev = __in_dev_get_rcu(netdev);
+		if (!in_dev) {
+			rcu_read_unlock();
 			goto skip_arp;
+		}
 
-		ifa = (struct in_ifaddr *)in_dev->ifa_list;
-		if (!ifa)
+		ifa = rcu_dereference(in_dev->ifa_list);
+		if (!ifa) {
+			rcu_read_unlock();
 			goto skip_arp;
+		}
 
 		pmConf->filters[i].patternSize = ETH_HLEN + /* Ethernet header*/
 			sizeof(struct arphdr) +		/* ARP header */
@@ -3677,7 +3683,9 @@ vmxnet3_suspend(struct device *device)
 
 		/* The Unicast IPv4 address in 'tip' field. */
 		arpreq += 2 * ETH_ALEN + sizeof(u32);
-		*(u32 *)arpreq = ifa->ifa_address;
+		*(__be32 *)arpreq = ifa->ifa_address;
+
+		rcu_read_unlock();
 
 		/* The mask for the relevant bits. */
 		pmConf->filters[i].mask[0] = 0x00;
@@ -3686,7 +3694,6 @@ vmxnet3_suspend(struct device *device)
 		pmConf->filters[i].mask[3] = 0x00;
 		pmConf->filters[i].mask[4] = 0xC0; /* IPv4 TIP */
 		pmConf->filters[i].mask[5] = 0x03; /* IPv4 TIP */
-		in_dev_put(in_dev);
 
 		pmConf->wakeUpEvents |= VMXNET3_PM_WAKEUP_FILTER;
 		i++;
diff --git a/drivers/net/wireless/ath/ath6kl/cfg80211.c b/drivers/net/wireless/ath/ath6kl/cfg80211.c
index 5477a014e1fb..37cf602d8adf 100644
--- a/drivers/net/wireless/ath/ath6kl/cfg80211.c
+++ b/drivers/net/wireless/ath/ath6kl/cfg80211.c
@@ -2194,13 +2194,13 @@ static int ath6kl_wow_suspend_vif(struct ath6kl_vif *vif,
 	if (!in_dev)
 		return 0;
 
-	ifa = in_dev->ifa_list;
+	ifa = rtnl_dereference(in_dev->ifa_list);
 	memset(&ips, 0, sizeof(ips));
 
 	/* Configure IP addr only if IP address count < MAX_IP_ADDRS */
 	while (index < MAX_IP_ADDRS && ifa) {
 		ips[index] = ifa->ifa_local;
-		ifa = ifa->ifa_next;
+		ifa = rtnl_dereference(ifa->ifa_next);
 		index++;
 	}
 
diff --git a/drivers/net/wireless/marvell/mwifiex/cfg80211.c b/drivers/net/wireless/marvell/mwifiex/cfg80211.c
index e11a4bb67172..5a7cdb981789 100644
--- a/drivers/net/wireless/marvell/mwifiex/cfg80211.c
+++ b/drivers/net/wireless/marvell/mwifiex/cfg80211.c
@@ -3268,7 +3268,7 @@ static void mwifiex_set_auto_arp_mef_entry(struct mwifiex_private *priv,
 			in_dev = __in_dev_get_rtnl(adapter->priv[i]->netdev);
 			if (!in_dev)
 				continue;
-			ifa = in_dev->ifa_list;
+			ifa = rtnl_dereference(in_dev->ifa_list);
 			if (!ifa || !ifa->ifa_local)
 				continue;
 			ips[i] = ifa->ifa_local;
diff --git a/drivers/staging/isdn/hysdn/hysdn_net.c b/drivers/staging/isdn/hysdn/hysdn_net.c
index 8e9c34f33d86..bea37ae30ebb 100644
--- a/drivers/staging/isdn/hysdn/hysdn_net.c
+++ b/drivers/staging/isdn/hysdn/hysdn_net.c
@@ -70,9 +70,13 @@ net_open(struct net_device *dev)
 		for (i = 0; i < ETH_ALEN; i++)
 			dev->dev_addr[i] = 0xfc;
 		if ((in_dev = dev->ip_ptr) != NULL) {
-			struct in_ifaddr *ifa = in_dev->ifa_list;
+			const struct in_ifaddr *ifa;
+
+			rcu_read_lock();
+			ifa = rcu_dereference(in_dev->ifa_list);
 			if (ifa != NULL)
 				memcpy(dev->dev_addr + (ETH_ALEN - sizeof(ifa->ifa_local)), &ifa->ifa_local, sizeof(ifa->ifa_local));
+			rcu_read_unlock();
 		}
 	} else
 		memcpy(dev->dev_addr, card->mac_addr, ETH_ALEN);