net: fix 64 bit counters on 32 bit arches

There is a small possibility that a reader gets incorrect values on 32
bit arches. SNMP applications could catch incorrect counters when a
32bit high part is changed by another stats consumer/provider.

One way to solve this is to add a rtnl_link_stats64 param to all
ndo_get_stats64() methods, and also add such a parameter to
dev_get_stats().

Rule is that we are not allowed to use dev->stats64 as a temporary
storage for 64bit stats, but a caller provided area (usually on stack)

Old drivers (only providing get_stats() method) need no changes.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/arch/s390/appldata/appldata_net_sum.c b/arch/s390/appldata/appldata_net_sum.c
index 9a9586f..f02e89c 100644 (file)
--- a/arch/s390/appldata/appldata_net_sum.c
+++ b/arch/s390/appldata/appldata_net_sum.c
@@ -85,7 +85,8 @@ static void appldata_get_net_sum_data(void *data)
 
        rcu_read_lock();
        for_each_netdev_rcu(&init_net, dev) {
-               const struct net_device_stats *stats = dev_get_stats(dev);
+               struct rtnl_link_stats64 temp;
+               const struct net_device_stats *stats = dev_get_stats(dev, &temp);
 
                rx_packets += stats->rx_packets;
                tx_packets += stats->tx_packets;

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index a95a41b..9bb9bfa 100644 (file)
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -3804,51 +3804,49 @@ static int bond_close(struct net_device *bond_dev)
        return 0;
 }
 
-static struct rtnl_link_stats64 *bond_get_stats(struct net_device *bond_dev)
+static struct rtnl_link_stats64 *bond_get_stats(struct net_device *bond_dev,
+                                               struct rtnl_link_stats64 *stats)
 {
        struct bonding *bond = netdev_priv(bond_dev);
-       struct rtnl_link_stats64 *stats = &bond_dev->stats64;
-       struct rtnl_link_stats64 local_stats;
+       struct rtnl_link_stats64 temp;
        struct slave *slave;
        int i;
 
-       memset(&local_stats, 0, sizeof(local_stats));
+       memset(stats, 0, sizeof(*stats));
 
        read_lock_bh(&bond->lock);
 
        bond_for_each_slave(bond, slave, i) {
                const struct rtnl_link_stats64 *sstats =
-                       dev_get_stats(slave->dev);
-
-               local_stats.rx_packets += sstats->rx_packets;
-               local_stats.rx_bytes += sstats->rx_bytes;
-               local_stats.rx_errors += sstats->rx_errors;
-               local_stats.rx_dropped += sstats->rx_dropped;
-
-               local_stats.tx_packets += sstats->tx_packets;
-               local_stats.tx_bytes += sstats->tx_bytes;
-               local_stats.tx_errors += sstats->tx_errors;
-               local_stats.tx_dropped += sstats->tx_dropped;
-
-               local_stats.multicast += sstats->multicast;
-               local_stats.collisions += sstats->collisions;
-
-               local_stats.rx_length_errors += sstats->rx_length_errors;
-               local_stats.rx_over_errors += sstats->rx_over_errors;
-               local_stats.rx_crc_errors += sstats->rx_crc_errors;
-               local_stats.rx_frame_errors += sstats->rx_frame_errors;
-               local_stats.rx_fifo_errors += sstats->rx_fifo_errors;
-               local_stats.rx_missed_errors += sstats->rx_missed_errors;
-
-               local_stats.tx_aborted_errors += sstats->tx_aborted_errors;
-               local_stats.tx_carrier_errors += sstats->tx_carrier_errors;
-               local_stats.tx_fifo_errors += sstats->tx_fifo_errors;
-               local_stats.tx_heartbeat_errors += sstats->tx_heartbeat_errors;
-               local_stats.tx_window_errors += sstats->tx_window_errors;
+                       dev_get_stats(slave->dev, &temp);
+
+               stats->rx_packets += sstats->rx_packets;
+               stats->rx_bytes += sstats->rx_bytes;
+               stats->rx_errors += sstats->rx_errors;
+               stats->rx_dropped += sstats->rx_dropped;
+
+               stats->tx_packets += sstats->tx_packets;
+               stats->tx_bytes += sstats->tx_bytes;
+               stats->tx_errors += sstats->tx_errors;
+               stats->tx_dropped += sstats->tx_dropped;
+
+               stats->multicast += sstats->multicast;
+               stats->collisions += sstats->collisions;
+
+               stats->rx_length_errors += sstats->rx_length_errors;
+               stats->rx_over_errors += sstats->rx_over_errors;
+               stats->rx_crc_errors += sstats->rx_crc_errors;
+               stats->rx_frame_errors += sstats->rx_frame_errors;
+               stats->rx_fifo_errors += sstats->rx_fifo_errors;
+               stats->rx_missed_errors += sstats->rx_missed_errors;
+
+               stats->tx_aborted_errors += sstats->tx_aborted_errors;
+               stats->tx_carrier_errors += sstats->tx_carrier_errors;
+               stats->tx_fifo_errors += sstats->tx_fifo_errors;
+               stats->tx_heartbeat_errors += sstats->tx_heartbeat_errors;
+               stats->tx_window_errors += sstats->tx_window_errors;
        }
 
-       memcpy(stats, &local_stats, sizeof(struct net_device_stats));
-
        read_unlock_bh(&bond->lock);
 
        return stats;

diff --git a/drivers/net/ixgbe/ixgbe_ethtool.c b/drivers/net/ixgbe/ixgbe_ethtool.c
index b35ef36..da54b38 100644 (file)
--- a/drivers/net/ixgbe/ixgbe_ethtool.c
+++ b/drivers/net/ixgbe/ixgbe_ethtool.c
@@ -55,7 +55,7 @@ struct ixgbe_stats {
                                offsetof(struct ixgbe_adapter, m)
 #define IXGBE_NETDEV_STAT(m)   NETDEV_STATS, \
                                sizeof(((struct net_device *)0)->m), \
-                               offsetof(struct net_device, m)
+                               offsetof(struct net_device, m) - offsetof(struct net_device, stats)
 
 static struct ixgbe_stats ixgbe_gstrings_stats[] = {
        {"rx_packets", IXGBE_NETDEV_STAT(stats.rx_packets)},
@@ -998,16 +998,18 @@ static void ixgbe_get_ethtool_stats(struct net_device *netdev,
        struct ixgbe_adapter *adapter = netdev_priv(netdev);
        u64 *queue_stat;
        int stat_count = sizeof(struct ixgbe_queue_stats) / sizeof(u64);
+       struct rtnl_link_stats64 temp;
+       const struct rtnl_link_stats64 *net_stats;
        int j, k;
        int i;
        char *p = NULL;
 
        ixgbe_update_stats(adapter);
-       dev_get_stats(netdev);
+       net_stats = dev_get_stats(netdev, &temp);
        for (i = 0; i < IXGBE_GLOBAL_STATS_LEN; i++) {
                switch (ixgbe_gstrings_stats[i].type) {
                case NETDEV_STATS:
-                       p = (char *) netdev +
+                       p = (char *) net_stats +
                                        ixgbe_gstrings_stats[i].stat_offset;
                        break;
                case IXGBE_STATS:

diff --git a/drivers/net/loopback.c b/drivers/net/loopback.c
index 4dd0510..9a09967 100644 (file)
--- a/drivers/net/loopback.c
+++ b/drivers/net/loopback.c
@@ -98,10 +98,10 @@ static netdev_tx_t loopback_xmit(struct sk_buff *skb,
        return NETDEV_TX_OK;
 }
 
-static struct rtnl_link_stats64 *loopback_get_stats64(struct net_device *dev)
+static struct rtnl_link_stats64 *loopback_get_stats64(struct net_device *dev,
+                                                     struct rtnl_link_stats64 *stats)
 {
        const struct pcpu_lstats __percpu *pcpu_lstats;
-       struct rtnl_link_stats64 *stats = &dev->stats64;
        u64 bytes = 0;
        u64 packets = 0;
        u64 drops = 0;

diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index e6d626e..6112f14 100644 (file)
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -431,12 +431,12 @@ static void macvlan_uninit(struct net_device *dev)
        free_percpu(vlan->rx_stats);
 }
 
-static struct rtnl_link_stats64 *macvlan_dev_get_stats64(struct net_device *dev)
+static struct rtnl_link_stats64 *macvlan_dev_get_stats64(struct net_device *dev,
+                                                        struct rtnl_link_stats64 *stats)
 {
-       struct rtnl_link_stats64 *stats = &dev->stats64;
        struct macvlan_dev *vlan = netdev_priv(dev);
 
-       dev_txq_stats_fold(dev, &dev->stats);
+       dev_txq_stats_fold(dev, (struct net_device_stats *)stats);
 
        if (vlan->rx_stats) {
                struct macvlan_rx_stats *p, accum = {0};

diff --git a/drivers/net/sfc/efx.c b/drivers/net/sfc/efx.c
index 35b3f29..ba674c5 100644 (file)
--- a/drivers/net/sfc/efx.c
+++ b/drivers/net/sfc/efx.c
@@ -1533,11 +1533,10 @@ static int efx_net_stop(struct net_device *net_dev)
 }
 
 /* Context: process, dev_base_lock or RTNL held, non-blocking. */
-static struct rtnl_link_stats64 *efx_net_stats(struct net_device *net_dev)
+static struct rtnl_link_stats64 *efx_net_stats(struct net_device *net_dev, struct rtnl_link_stats64 *stats)
 {
        struct efx_nic *efx = netdev_priv(net_dev);
        struct efx_mac_stats *mac_stats = &efx->mac_stats;
-       struct rtnl_link_stats64 *stats = &net_dev->stats64;
 
        spin_lock_bh(&efx->stats_lock);
        efx->type->update_stats(efx);

diff --git a/drivers/net/sfc/ethtool.c b/drivers/net/sfc/ethtool.c
index 3b8b0a0..fd19d6a 100644 (file)
--- a/drivers/net/sfc/ethtool.c
+++ b/drivers/net/sfc/ethtool.c
@@ -469,12 +469,13 @@ static void efx_ethtool_get_stats(struct net_device *net_dev,
        struct efx_mac_stats *mac_stats = &efx->mac_stats;
        struct efx_ethtool_stat *stat;
        struct efx_channel *channel;
+       struct rtnl_link_stats64 temp;
        int i;
 
        EFX_BUG_ON_PARANOID(stats->n_stats != EFX_ETHTOOL_NUM_STATS);
 
        /* Update MAC and NIC statistics */
-       dev_get_stats(net_dev);
+       dev_get_stats(net_dev, &temp);
 
        /* Fill detailed statistics buffer */
        for (i = 0; i < EFX_ETHTOOL_NUM_STATS; i++) {

diff --git a/drivers/parisc/led.c b/drivers/parisc/led.c
index 188bc84..18dff43 100644 (file)
--- a/drivers/parisc/led.c
+++ b/drivers/parisc/led.c
@@ -355,12 +355,13 @@ static __inline__ int led_get_net_activity(void)
        rcu_read_lock();
        for_each_netdev_rcu(&init_net, dev) {
            const struct net_device_stats *stats;
+           struct rtnl_link_stats64 temp;
            struct in_device *in_dev = __in_dev_get_rcu(dev);
            if (!in_dev || !in_dev->ifa_list)
                continue;
            if (ipv4_is_loopback(in_dev->ifa_list->ifa_local))
                continue;
-           stats = dev_get_stats(dev);
+           stats = dev_get_stats(dev, &temp);
            rx_total += stats->rx_packets;
            tx_total += stats->tx_packets;
        }

diff --git a/drivers/scsi/fcoe/fcoe.c b/drivers/scsi/fcoe/fcoe.c
index 44a0759..1a429ed 100644 (file)
--- a/drivers/scsi/fcoe/fcoe.c
+++ b/drivers/scsi/fcoe/fcoe.c
@@ -2653,6 +2653,7 @@ static void fcoe_get_lesb(struct fc_lport *lport,
        u32 lfc, vlfc, mdac;
        struct fcoe_dev_stats *devst;
        struct fcoe_fc_els_lesb *lesb;
+       struct rtnl_link_stats64 temp;
        struct net_device *netdev = fcoe_netdev(lport);
 
        lfc = 0;
@@ -2669,7 +2670,7 @@ static void fcoe_get_lesb(struct fc_lport *lport,
        lesb->lesb_link_fail = htonl(lfc);
        lesb->lesb_vlink_fail = htonl(vlfc);
        lesb->lesb_miss_fka = htonl(mdac);
-       lesb->lesb_fcs_error = htonl(dev_get_stats(netdev)->rx_crc_errors);
+       lesb->lesb_fcs_error = htonl(dev_get_stats(netdev, &temp)->rx_crc_errors);
 }
 
 /**

diff --git a/drivers/staging/batman-adv/hard-interface.c b/drivers/staging/batman-adv/hard-interface.c
index 5ede9c2..96c86c8 100644 (file)
--- a/drivers/staging/batman-adv/hard-interface.c
+++ b/drivers/staging/batman-adv/hard-interface.c
@@ -440,6 +440,7 @@ int batman_skb_recv(struct sk_buff *skb, struct net_device *dev,
        struct batman_packet *batman_packet;
        struct batman_if *batman_if;
        struct net_device_stats *stats;
+       struct rtnl_link_stats64 temp;
        int ret;
 
        skb = skb_share_check(skb, GFP_ATOMIC);
@@ -468,7 +469,7 @@ int batman_skb_recv(struct sk_buff *skb, struct net_device *dev,
        if (batman_if->if_status != IF_ACTIVE)
                goto err_free;
 
-       stats = (struct net_device_stats *)dev_get_stats(skb->dev);
+       stats = (struct net_device_stats *)dev_get_stats(skb->dev, &temp);
        if (stats) {
                stats->rx_packets++;
                stats->rx_bytes += skb->len;

diff --git a/drivers/usb/gadget/rndis.c b/drivers/usb/gadget/rndis.c
index fb69b01..020fa5a 100644 (file)
--- a/drivers/usb/gadget/rndis.c
+++ b/drivers/usb/gadget/rndis.c
@@ -171,6 +171,7 @@ gen_ndis_query_resp (int configNr, u32 OID, u8 *buf, unsigned buf_len,
        int                     i, count;
        rndis_query_cmplt_type  *resp;
        struct net_device       *net;
+       struct rtnl_link_stats64 temp;
        const struct rtnl_link_stats64 *stats;
 
        if (!r) return -ENOMEM;
@@ -194,7 +195,7 @@ gen_ndis_query_resp (int configNr, u32 OID, u8 *buf, unsigned buf_len,
        resp->InformationBufferOffset = cpu_to_le32 (16);
 
        net = rndis_per_dev_params[configNr].dev;
-       stats = dev_get_stats(net);
+       stats = dev_get_stats(net, &temp);
 
        switch (OID) {
 

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 4d27368..60de653 100644 (file)
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -666,7 +666,8 @@ struct netdev_rx_queue {
  *     Callback uses when the transmitter has not made any progress
  *     for dev->watchdog ticks.
  *
- * struct rtnl_link_stats64* (*ndo_get_stats64)(struct net_device *dev);
+ * struct rtnl_link_stats64* (*ndo_get_stats64)(struct net_device *dev
+ *                      struct rtnl_link_stats64 *storage);
  * struct net_device_stats* (*ndo_get_stats)(struct net_device *dev);
  *     Called when a user wants to get the network device usage
  *     statistics. Drivers must do one of the following:
@@ -733,7 +734,8 @@ struct net_device_ops {
                                                   struct neigh_parms *);
        void                    (*ndo_tx_timeout) (struct net_device *dev);
 
-       struct rtnl_link_stats64* (*ndo_get_stats64)(struct net_device *dev);
+       struct rtnl_link_stats64* (*ndo_get_stats64)(struct net_device *dev,
+                                                    struct rtnl_link_stats64 *storage);
        struct net_device_stats* (*ndo_get_stats)(struct net_device *dev);
 
        void                    (*ndo_vlan_rx_register)(struct net_device *dev,
@@ -2139,8 +2141,10 @@ extern void              netdev_features_change(struct net_device *dev);
 /* Load a device via the kmod */
 extern void            dev_load(struct net *net, const char *name);
 extern void            dev_mcast_init(void);
-extern const struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev);
-extern void            dev_txq_stats_fold(const struct net_device *dev, struct net_device_stats *stats);
+extern const struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev,
+                                                    struct rtnl_link_stats64 *storage);
+extern void            dev_txq_stats_fold(const struct net_device *dev,
+                                          struct net_device_stats *stats);
 
 extern int             netdev_max_backlog;
 extern int             netdev_tstamp_prequeue;

diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c
index c6456cb..7865a4c 100644 (file)
--- a/net/8021q/vlan_dev.c
+++ b/net/8021q/vlan_dev.c
@@ -803,11 +803,9 @@ static u32 vlan_ethtool_get_flags(struct net_device *dev)
        return dev_ethtool_get_flags(vlan->real_dev);
 }
 
-static struct rtnl_link_stats64 *vlan_dev_get_stats64(struct net_device *dev)
+static struct rtnl_link_stats64 *vlan_dev_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats)
 {
-       struct rtnl_link_stats64 *stats = &dev->stats64;
-
-       dev_txq_stats_fold(dev, &dev->stats);
+       dev_txq_stats_fold(dev, (struct net_device_stats *)stats);
 
        if (vlan_dev_info(dev)->vlan_rx_stats) {
                struct vlan_rx_stats *p, accum = {0};

diff --git a/net/8021q/vlanproc.c b/net/8021q/vlanproc.c
index df56f5c..80e280f 100644 (file)
--- a/net/8021q/vlanproc.c
+++ b/net/8021q/vlanproc.c
@@ -278,6 +278,7 @@ static int vlandev_seq_show(struct seq_file *seq, void *offset)
 {
        struct net_device *vlandev = (struct net_device *) seq->private;
        const struct vlan_dev_info *dev_info = vlan_dev_info(vlandev);
+       struct rtnl_link_stats64 temp;
        const struct rtnl_link_stats64 *stats;
        static const char fmt[] = "%30s %12lu\n";
        static const char fmt64[] = "%30s %12llu\n";
@@ -286,7 +287,7 @@ static int vlandev_seq_show(struct seq_file *seq, void *offset)
        if (!is_vlan_dev(vlandev))
                return 0;
 
-       stats = dev_get_stats(vlandev);
+       stats = dev_get_stats(vlandev, &temp);
        seq_printf(seq,
                   "%s  VID: %d  REORDER_HDR: %i  dev->priv_flags: %hx\n",
                   vlandev->name, dev_info->vlan_id,

diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c
index edf639e..075c435 100644 (file)
--- a/net/bridge/br_device.c
+++ b/net/bridge/br_device.c
@@ -98,10 +98,10 @@ static int br_dev_stop(struct net_device *dev)
        return 0;
 }
 
-static struct rtnl_link_stats64 *br_get_stats64(struct net_device *dev)
+static struct rtnl_link_stats64 *br_get_stats64(struct net_device *dev,
+                                               struct rtnl_link_stats64 *stats)
 {
        struct net_bridge *br = netdev_priv(dev);
-       struct rtnl_link_stats64 *stats = &dev->stats64;
        struct br_cpu_netstats tmp, sum = { 0 };
        unsigned int cpu;
 

diff --git a/net/core/dev.c b/net/core/dev.c
index 93b8929..92482d7 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -3703,7 +3703,8 @@ void dev_seq_stop(struct seq_file *seq, void *v)
 
 static void dev_seq_printf_stats(struct seq_file *seq, struct net_device *dev)
 {
-       const struct rtnl_link_stats64 *stats = dev_get_stats(dev);
+       struct rtnl_link_stats64 temp;
+       const struct rtnl_link_stats64 *stats = dev_get_stats(dev, &temp);
 
        seq_printf(seq, "%6s: %7llu %7llu %4llu %4llu %4llu %5llu %10llu %9llu "
                   "%8llu %7llu %4llu %4llu %4llu %5llu %7llu %10llu\n",
@@ -5281,23 +5282,29 @@ EXPORT_SYMBOL(dev_txq_stats_fold);
 /**
  *     dev_get_stats   - get network device statistics
  *     @dev: device to get statistics from
+ *     @storage: place to store stats
  *
  *     Get network statistics from device. The device driver may provide
  *     its own method by setting dev->netdev_ops->get_stats64 or
  *     dev->netdev_ops->get_stats; otherwise the internal statistics
  *     structure is used.
  */
-const struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev)
+const struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev,
+                                             struct rtnl_link_stats64 *storage)
 {
        const struct net_device_ops *ops = dev->netdev_ops;
 
-       if (ops->ndo_get_stats64)
-               return ops->ndo_get_stats64(dev);
-       if (ops->ndo_get_stats)
-               return (struct rtnl_link_stats64 *)ops->ndo_get_stats(dev);
-
-       dev_txq_stats_fold(dev, &dev->stats);
-       return &dev->stats64;
+       if (ops->ndo_get_stats64) {
+               memset(storage, 0, sizeof(*storage));
+               return ops->ndo_get_stats64(dev, storage);
+       }
+       if (ops->ndo_get_stats) {
+               memcpy(storage, ops->ndo_get_stats(dev), sizeof(*storage));
+               return storage;
+       }
+       memcpy(storage, &dev->stats, sizeof(*storage));
+       dev_txq_stats_fold(dev, (struct net_device_stats *)storage);
+       return storage;
 }
 EXPORT_SYMBOL(dev_get_stats);
 

diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index ea3bb4c..914f42b 100644 (file)
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -330,7 +330,9 @@ static ssize_t netstat_show(const struct device *d,
 
        read_lock(&dev_base_lock);
        if (dev_isalive(dev)) {
-               const struct rtnl_link_stats64 *stats = dev_get_stats(dev);
+               struct rtnl_link_stats64 temp;
+               const struct rtnl_link_stats64 *stats = dev_get_stats(dev, &temp);
+
                ret = sprintf(buf, fmt_u64, *(u64 *)(((u8 *) stats) + offset));
        }
        read_unlock(&dev_base_lock);

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index e645778..5e773ea 100644 (file)
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -791,6 +791,7 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb, struct net_device *dev,
 {
        struct ifinfomsg *ifm;
        struct nlmsghdr *nlh;
+       struct rtnl_link_stats64 temp;
        const struct rtnl_link_stats64 *stats;
        struct nlattr *attr;
 
@@ -847,7 +848,7 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb, struct net_device *dev,
        if (attr == NULL)
                goto nla_put_failure;
 
-       stats = dev_get_stats(dev);
+       stats = dev_get_stats(dev, &temp);
        copy_rtnl_link_stats(nla_data(attr), stats);
 
        attr = nla_reserve(skb, IFLA_STATS64,