6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Eric Dumazet edumazet@google.com
[ Upstream commit 004d138364fd10dd5ff8ceb54cfdc2d792a7b338 ]
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 edumazet@google.com Signed-off-by: David S. Miller davem@davemloft.net Stable-dep-of: 4893b8b3ef8d ("hsr: Simplify code for announcing HSR nodes timer setup") Signed-off-by: Sasha Levin sashal@kernel.org --- 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 65e9ed3851425..4488faf059a36 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 c469d1c4db5d7..cb43f5aebfbcc 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 fccaa5bac0ed0..5a9487af44e00 100644 --- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -307,11 +307,9 @@ 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 89964270cf27f..7ea66de1442cc 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -880,9 +880,9 @@ 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 dd4b5f0aa1318..cd337385e8592 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 d1806eee1687d..01f4502916a12 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -6011,7 +6011,7 @@ 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)