From 28172739f0a276eb8d6ca917b3974c2edb036da3 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 7 Jul 2010 14:58:56 -0700 Subject: 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 Signed-off-by: David S. Miller --- net/8021q/vlan_dev.c | 6 ++---- net/8021q/vlanproc.c | 3 ++- net/bridge/br_device.c | 4 ++-- net/core/dev.c | 25 ++++++++++++++++--------- net/core/net-sysfs.c | 4 +++- net/core/rtnetlink.c | 3 ++- 6 files changed, 27 insertions(+), 18 deletions(-) (limited to 'net') diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c index c6456cb842f..7865a4ce525 100644 --- 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 df56f5ce887..80e280f5668 100644 --- 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 edf639e9628..075c435ad22 100644 --- 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 93b8929fa21..92482d7a87a 100644 --- 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 ea3bb4c3b87..914f42b0f03 100644 --- 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 e645778e9b7..5e773ea2201 100644 --- 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, -- cgit v1.2.3