ipv6: prepare inet6_fill_ifinfo() for RCU protection

We want to use RCU protection instead of RTNL
for inet6_fill_ifinfo().

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index f07c8374f29cb936fe11236fc63e06e741b1c965..09023e44db4e2c3a2133afc52ba5a335d6030646 100644 (file)
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -4354,8 +4354,10 @@ static inline bool netif_testing(const struct net_device *dev)
  */
 static inline bool netif_oper_up(const struct net_device *dev)
 {
-       return (dev->operstate == IF_OPER_UP ||
-               dev->operstate == IF_OPER_UNKNOWN /* backward compat */);
+       unsigned int operstate = READ_ONCE(dev->operstate);
+
+       return  operstate == IF_OPER_UP ||
+               operstate == IF_OPER_UNKNOWN /* backward compat */;
 }
 
 /**

diff --git a/net/core/dev.c b/net/core/dev.c
index 0628d8ff1ed932efdd45ab7b79599dcfcca6c4eb..275fd5259a4a92d0bd2e145d66a716248b6c2804 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -8632,12 +8632,12 @@ unsigned int dev_get_flags(const struct net_device *dev)
 {
        unsigned int flags;
 
-       flags = (dev->flags & ~(IFF_PROMISC |
+       flags = (READ_ONCE(dev->flags) & ~(IFF_PROMISC |
                                IFF_ALLMULTI |
                                IFF_RUNNING |
                                IFF_LOWER_UP |
                                IFF_DORMANT)) |
-               (dev->gflags & (IFF_PROMISC |
+               (READ_ONCE(dev->gflags) & (IFF_PROMISC |
                                IFF_ALLMULTI));
 
        if (netif_running(dev)) {

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index a56dad307fe31c4779617277f2bc4a6b691c47b7..daa81556d1180b8bfd51d9b259c069b549883901 100644 (file)
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -6062,6 +6062,7 @@ static int inet6_fill_ifinfo(struct sk_buff *skb, struct inet6_dev *idev,
        struct net_device *dev = idev->dev;
        struct ifinfomsg *hdr;
        struct nlmsghdr *nlh;
+       int ifindex, iflink;
        void *protoinfo;
 
        nlh = nlmsg_put(skb, portid, seq, event, sizeof(*hdr), flags);
@@ -6072,16 +6073,18 @@ static int inet6_fill_ifinfo(struct sk_buff *skb, struct inet6_dev *idev,
        hdr->ifi_family = AF_INET6;
        hdr->__ifi_pad = 0;
        hdr->ifi_type = dev->type;
-       hdr->ifi_index = dev->ifindex;
+       ifindex = READ_ONCE(dev->ifindex);
+       hdr->ifi_index = ifindex;
        hdr->ifi_flags = dev_get_flags(dev);
        hdr->ifi_change = 0;
 
+       iflink = dev_get_iflink(dev);
        if (nla_put_string(skb, IFLA_IFNAME, dev->name) ||
            (dev->addr_len &&
             nla_put(skb, IFLA_ADDRESS, dev->addr_len, dev->dev_addr)) ||
-           nla_put_u32(skb, IFLA_MTU, dev->mtu) ||
-           (dev->ifindex != dev_get_iflink(dev) &&
-            nla_put_u32(skb, IFLA_LINK, dev_get_iflink(dev))) ||
+           nla_put_u32(skb, IFLA_MTU, READ_ONCE(dev->mtu)) ||
+           (ifindex != iflink &&
+            nla_put_u32(skb, IFLA_LINK, iflink)) ||
            nla_put_u8(skb, IFLA_OPERSTATE,
                       netif_running(dev) ? READ_ONCE(dev->operstate) : IF_OPER_DOWN))
                goto nla_put_failure;