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Miller" , Jakub Kicinski , Paolo Abeni Cc: netdev@vger.kernel.org, eric.dumazet@gmail.com, Eric Dumazet X-Patchwork-Delegate: kuba@kernel.org operstate_show() can omit dev_base_lock acquisition only to read dev->operstate. Annotate accesses to dev->operstate. Writers still acquire dev_base_lock for mutual exclusion. Signed-off-by: Eric Dumazet --- net/bridge/br_netlink.c | 3 ++- net/core/link_watch.c | 4 ++-- net/core/net-sysfs.c | 4 +--- net/core/rtnetlink.c | 4 ++-- net/hsr/hsr_device.c | 10 +++++----- net/ipv6/addrconf.c | 2 +- 6 files changed, 13 insertions(+), 14 deletions(-) diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c index 5ad4abfcb7ba3960bf69613ae7975180ae48854b..2cf4fc756263992eefe6a3580410766fea0c2c1f 100644 --- a/net/bridge/br_netlink.c +++ b/net/bridge/br_netlink.c @@ -455,7 +455,8 @@ static int br_fill_ifinfo(struct sk_buff *skb, u32 filter_mask, const struct net_device *dev, bool getlink) { - u8 operstate = netif_running(dev) ? dev->operstate : IF_OPER_DOWN; + u8 operstate = netif_running(dev) ? READ_ONCE(dev->operstate) : + IF_OPER_DOWN; struct nlattr *af = NULL; struct net_bridge *br; struct ifinfomsg *hdr; diff --git a/net/core/link_watch.c b/net/core/link_watch.c index 429571c258da7720baf387fef81081a56a655ef5..1b93e054c9a3cfcdd5d1251a9982d88a071abbaa 100644 --- a/net/core/link_watch.c +++ b/net/core/link_watch.c @@ -67,7 +67,7 @@ static void rfc2863_policy(struct net_device *dev) { unsigned char operstate = default_operstate(dev); - if (operstate == dev->operstate) + if (operstate == READ_ONCE(dev->operstate)) return; write_lock(&dev_base_lock); @@ -87,7 +87,7 @@ static void rfc2863_policy(struct net_device *dev) break; } - dev->operstate = operstate; + WRITE_ONCE(dev->operstate, operstate); write_unlock(&dev_base_lock); } diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c index 23ef2df549c3036a702f3be1dca1eda14ee5e76f..c5d164b8c6bfb53793f8422063c6281d6339b36e 100644 --- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -325,11 +325,9 @@ static ssize_t operstate_show(struct device *dev, const struct net_device *netdev = to_net_dev(dev); unsigned char operstate; - read_lock(&dev_base_lock); - operstate = netdev->operstate; + operstate = READ_ONCE(netdev->operstate); if (!netif_running(netdev)) operstate = IF_OPER_DOWN; - read_unlock(&dev_base_lock); if (operstate >= ARRAY_SIZE(operstates)) return -EINVAL; /* should not happen */ diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 8d95e0863534f80cecceb2dd4a7b2a16f7f4bca3..4e797326c88fe1e23ca66e82103176767fe5c32e 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -866,9 +866,9 @@ static void set_operstate(struct net_device *dev, unsigned char transition) break; } - if (dev->operstate != operstate) { + if (READ_ONCE(dev->operstate) != operstate) { write_lock(&dev_base_lock); - dev->operstate = operstate; + WRITE_ONCE(dev->operstate, operstate); write_unlock(&dev_base_lock); netdev_state_change(dev); } diff --git a/net/hsr/hsr_device.c b/net/hsr/hsr_device.c index 9d71b66183daf94e19945d75cfb5c33df6ce346c..be0e43f46556e028e675147e63c6b787aa72e894 100644 --- a/net/hsr/hsr_device.c +++ b/net/hsr/hsr_device.c @@ -31,8 +31,8 @@ static bool is_slave_up(struct net_device *dev) static void __hsr_set_operstate(struct net_device *dev, int transition) { write_lock(&dev_base_lock); - if (dev->operstate != transition) { - dev->operstate = transition; + if (READ_ONCE(dev->operstate) != transition) { + WRITE_ONCE(dev->operstate, transition); write_unlock(&dev_base_lock); netdev_state_change(dev); } else { @@ -78,14 +78,14 @@ static void hsr_check_announce(struct net_device *hsr_dev, hsr = netdev_priv(hsr_dev); - if (hsr_dev->operstate == IF_OPER_UP && old_operstate != IF_OPER_UP) { + if (READ_ONCE(hsr_dev->operstate) == IF_OPER_UP && old_operstate != IF_OPER_UP) { /* Went up */ hsr->announce_count = 0; mod_timer(&hsr->announce_timer, jiffies + msecs_to_jiffies(HSR_ANNOUNCE_INTERVAL)); } - if (hsr_dev->operstate != IF_OPER_UP && old_operstate == IF_OPER_UP) + if (READ_ONCE(hsr_dev->operstate) != IF_OPER_UP && old_operstate == IF_OPER_UP) /* Went down */ del_timer(&hsr->announce_timer); } @@ -100,7 +100,7 @@ void hsr_check_carrier_and_operstate(struct hsr_priv *hsr) /* netif_stacked_transfer_operstate() cannot be used here since * it doesn't set IF_OPER_LOWERLAYERDOWN (?) */ - old_operstate = master->dev->operstate; + old_operstate = READ_ONCE(master->dev->operstate); has_carrier = hsr_check_carrier(master); hsr_set_operstate(master, has_carrier); hsr_check_announce(master->dev, old_operstate); diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index d63f5d063f073cb53f52e187efdbd09b8f78d622..1122c9ef09f6210fc373d9678a9da1ec1a3e78fa 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -5998,7 +5998,7 @@ static int inet6_fill_ifinfo(struct sk_buff *skb, struct inet6_dev *idev, (dev->ifindex != dev_get_iflink(dev) && nla_put_u32(skb, IFLA_LINK, dev_get_iflink(dev))) || nla_put_u8(skb, IFLA_OPERSTATE, - netif_running(dev) ? dev->operstate : IF_OPER_DOWN)) + netif_running(dev) ? READ_ONCE(dev->operstate) : IF_OPER_DOWN)) goto nla_put_failure; protoinfo = nla_nest_start_noflag(skb, IFLA_PROTINFO); if (!protoinfo)