net: ipv4: provide __rcu annotation for ifa_list

[linux-2.6-microblaze.git] / net / ipv4 / devinet.c

diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index b45421b..ebaea05 100644 (file)
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -194,7 +194,8 @@ static void rtmsg_ifa(int event, struct in_ifaddr *, struct nlmsghdr *, u32);
 
 static BLOCKING_NOTIFIER_HEAD(inetaddr_chain);
 static BLOCKING_NOTIFIER_HEAD(inetaddr_validator_chain);
-static void inet_del_ifa(struct in_device *in_dev, struct in_ifaddr **ifap,
+static void inet_del_ifa(struct in_device *in_dev,
+                        struct in_ifaddr __rcu **ifap,
                         int destroy);
 #ifdef CONFIG_SYSCTL
 static int devinet_sysctl_register(struct in_device *idev);
@@ -300,8 +301,8 @@ static void in_dev_rcu_put(struct rcu_head *head)
 
 static void inetdev_destroy(struct in_device *in_dev)
 {
-       struct in_ifaddr *ifa;
        struct net_device *dev;
+       struct in_ifaddr *ifa;
 
        ASSERT_RTNL();
 
@@ -311,7 +312,7 @@ static void inetdev_destroy(struct in_device *in_dev)
 
        ip_mc_destroy_dev(in_dev);
 
-       while ((ifa = in_dev->ifa_list) != NULL) {
+       while ((ifa = rtnl_dereference(in_dev->ifa_list)) != NULL) {
                inet_del_ifa(in_dev, &in_dev->ifa_list, 0);
                inet_free_ifa(ifa);
        }
@@ -342,17 +343,20 @@ int inet_addr_onlink(struct in_device *in_dev, __be32 a, __be32 b)
        return 0;
 }
 
-static void __inet_del_ifa(struct in_device *in_dev, struct in_ifaddr **ifap,
-                        int destroy, struct nlmsghdr *nlh, u32 portid)
+static void __inet_del_ifa(struct in_device *in_dev,
+                          struct in_ifaddr __rcu **ifap,
+                          int destroy, struct nlmsghdr *nlh, u32 portid)
 {
        struct in_ifaddr *promote = NULL;
-       struct in_ifaddr *ifa, *ifa1 = *ifap;
-       struct in_ifaddr *last_prim = in_dev->ifa_list;
+       struct in_ifaddr *ifa, *ifa1;
+       struct in_ifaddr *last_prim;
        struct in_ifaddr *prev_prom = NULL;
        int do_promote = IN_DEV_PROMOTE_SECONDARIES(in_dev);
 
        ASSERT_RTNL();
 
+       ifa1 = rtnl_dereference(*ifap);
+       last_prim = rtnl_dereference(in_dev->ifa_list);
        if (in_dev->dead)
                goto no_promotions;
 
@@ -361,9 +365,9 @@ static void __inet_del_ifa(struct in_device *in_dev, struct in_ifaddr **ifap,
         **/
 
        if (!(ifa1->ifa_flags & IFA_F_SECONDARY)) {
-               struct in_ifaddr **ifap1 = &ifa1->ifa_next;
+               struct in_ifaddr __rcu **ifap1 = &ifa1->ifa_next;
 
-               while ((ifa = *ifap1) != NULL) {
+               while ((ifa = rtnl_dereference(*ifap1)) != NULL) {
                        if (!(ifa->ifa_flags & IFA_F_SECONDARY) &&
                            ifa1->ifa_scope <= ifa->ifa_scope)
                                last_prim = ifa;
@@ -396,7 +400,7 @@ static void __inet_del_ifa(struct in_device *in_dev, struct in_ifaddr **ifap,
         * and later to add them back with new prefsrc. Do this
         * while all addresses are on the device list.
         */
-       for (ifa = promote; ifa; ifa = ifa->ifa_next) {
+       for (ifa = promote; ifa; ifa = rtnl_dereference(ifa->ifa_next)) {
                if (ifa1->ifa_mask == ifa->ifa_mask &&
                    inet_ifa_match(ifa1->ifa_address, ifa))
                        fib_del_ifaddr(ifa, ifa1);
@@ -422,19 +426,24 @@ no_promotions:
        blocking_notifier_call_chain(&inetaddr_chain, NETDEV_DOWN, ifa1);
 
        if (promote) {
-               struct in_ifaddr *next_sec = promote->ifa_next;
+               struct in_ifaddr *next_sec;
 
+               next_sec = rtnl_dereference(promote->ifa_next);
                if (prev_prom) {
-                       prev_prom->ifa_next = promote->ifa_next;
-                       promote->ifa_next = last_prim->ifa_next;
-                       last_prim->ifa_next = promote;
+                       struct in_ifaddr *last_sec;
+
+                       last_sec = rtnl_dereference(last_prim->ifa_next);
+                       rcu_assign_pointer(prev_prom->ifa_next, next_sec);
+                       rcu_assign_pointer(promote->ifa_next, last_sec);
+                       rcu_assign_pointer(last_prim->ifa_next, promote);
                }
 
                promote->ifa_flags &= ~IFA_F_SECONDARY;
                rtmsg_ifa(RTM_NEWADDR, promote, nlh, portid);
                blocking_notifier_call_chain(&inetaddr_chain,
                                NETDEV_UP, promote);
-               for (ifa = next_sec; ifa; ifa = ifa->ifa_next) {
+               for (ifa = next_sec; ifa;
+                    ifa = rtnl_dereference(ifa->ifa_next)) {
                        if (ifa1->ifa_mask != ifa->ifa_mask ||
                            !inet_ifa_match(ifa1->ifa_address, ifa))
                                        continue;
@@ -446,7 +455,8 @@ no_promotions:
                inet_free_ifa(ifa1);
 }
 
-static void inet_del_ifa(struct in_device *in_dev, struct in_ifaddr **ifap,
+static void inet_del_ifa(struct in_device *in_dev,
+                        struct in_ifaddr __rcu **ifap,
                         int destroy)
 {
        __inet_del_ifa(in_dev, ifap, destroy, NULL, 0);
@@ -459,9 +469,10 @@ static DECLARE_DELAYED_WORK(check_lifetime_work, check_lifetime);
 static int __inet_insert_ifa(struct in_ifaddr *ifa, struct nlmsghdr *nlh,
                             u32 portid, struct netlink_ext_ack *extack)
 {
+       struct in_ifaddr __rcu **last_primary, **ifap;
        struct in_device *in_dev = ifa->ifa_dev;
-       struct in_ifaddr *ifa1, **ifap, **last_primary;
        struct in_validator_info ivi;
+       struct in_ifaddr *ifa1;
        int ret;
 
        ASSERT_RTNL();
@@ -474,8 +485,10 @@ static int __inet_insert_ifa(struct in_ifaddr *ifa, struct nlmsghdr *nlh,
        ifa->ifa_flags &= ~IFA_F_SECONDARY;
        last_primary = &in_dev->ifa_list;
 
-       for (ifap = &in_dev->ifa_list; (ifa1 = *ifap) != NULL;
-            ifap = &ifa1->ifa_next) {
+       ifap = &in_dev->ifa_list;
+       ifa1 = rtnl_dereference(*ifap);
+
+       while (ifa1) {
                if (!(ifa1->ifa_flags & IFA_F_SECONDARY) &&
                    ifa->ifa_scope <= ifa1->ifa_scope)
                        last_primary = &ifa1->ifa_next;
@@ -491,6 +504,9 @@ static int __inet_insert_ifa(struct in_ifaddr *ifa, struct nlmsghdr *nlh,
                        }
                        ifa->ifa_flags |= IFA_F_SECONDARY;
                }
+
+               ifap = &ifa1->ifa_next;
+               ifa1 = rtnl_dereference(*ifap);
        }
 
        /* Allow any devices that wish to register ifaddr validtors to weigh
@@ -516,8 +532,8 @@ static int __inet_insert_ifa(struct in_ifaddr *ifa, struct nlmsghdr *nlh,
                ifap = last_primary;
        }
 
-       ifa->ifa_next = *ifap;
-       *ifap = ifa;
+       rcu_assign_pointer(ifa->ifa_next, *ifap);
+       rcu_assign_pointer(*ifap, ifa);
 
        inet_hash_insert(dev_net(in_dev->dev), ifa);
 
@@ -617,10 +633,12 @@ static int inet_rtm_deladdr(struct sk_buff *skb, struct nlmsghdr *nlh,
                            struct netlink_ext_ack *extack)
 {
        struct net *net = sock_net(skb->sk);
+       struct in_ifaddr __rcu **ifap;
        struct nlattr *tb[IFA_MAX+1];
        struct in_device *in_dev;
        struct ifaddrmsg *ifm;
-       struct in_ifaddr *ifa, **ifap;
+       struct in_ifaddr *ifa;
+
        int err = -EINVAL;
 
        ASSERT_RTNL();
@@ -637,7 +655,7 @@ static int inet_rtm_deladdr(struct sk_buff *skb, struct nlmsghdr *nlh,
                goto errout;
        }
 
-       for (ifap = &in_dev->ifa_list; (ifa = *ifap) != NULL;
+       for (ifap = &in_dev->ifa_list; (ifa = rtnl_dereference(*ifap)) != NULL;
             ifap = &ifa->ifa_next) {
                if (tb[IFA_LOCAL] &&
                    ifa->ifa_local != nla_get_in_addr(tb[IFA_LOCAL]))
@@ -725,15 +743,20 @@ static void check_lifetime(struct work_struct *work)
 
                        if (ifa->ifa_valid_lft != INFINITY_LIFE_TIME &&
                            age >= ifa->ifa_valid_lft) {
-                               struct in_ifaddr **ifap;
-
-                               for (ifap = &ifa->ifa_dev->ifa_list;
-                                    *ifap != NULL; ifap = &(*ifap)->ifa_next) {
-                                       if (*ifap == ifa) {
+                               struct in_ifaddr __rcu **ifap;
+                               struct in_ifaddr *tmp;
+
+                               ifap = &ifa->ifa_dev->ifa_list;
+                               tmp = rtnl_dereference(*ifap);
+                               while (tmp) {
+                                       tmp = rtnl_dereference(tmp->ifa_next);
+                                       if (rtnl_dereference(*ifap) == ifa) {
                                                inet_del_ifa(ifa->ifa_dev,
                                                             ifap, 1);
                                                break;
                                        }
+                                       ifap = &tmp->ifa_next;
+                                       tmp = rtnl_dereference(*ifap);
                                }
                        } else if (ifa->ifa_preferred_lft !=
                                   INFINITY_LIFE_TIME &&
@@ -977,8 +1000,8 @@ int devinet_ioctl(struct net *net, unsigned int cmd, struct ifreq *ifr)
 {
        struct sockaddr_in sin_orig;
        struct sockaddr_in *sin = (struct sockaddr_in *)&ifr->ifr_addr;
+       struct in_ifaddr __rcu **ifap = NULL;
        struct in_device *in_dev;
-       struct in_ifaddr **ifap = NULL;
        struct in_ifaddr *ifa = NULL;
        struct net_device *dev;
        char *colon;
@@ -1049,7 +1072,9 @@ int devinet_ioctl(struct net *net, unsigned int cmd, struct ifreq *ifr)
                        /* note: we only do this for a limited set of ioctls
                           and only if the original address family was AF_INET.
                           This is checked above. */
-                       for (ifap = &in_dev->ifa_list; (ifa = *ifap) != NULL;
+
+                       for (ifap = &in_dev->ifa_list;
+                            (ifa = rtnl_dereference(*ifap)) != NULL;
                             ifap = &ifa->ifa_next) {
                                if (!strcmp(ifr->ifr_name, ifa->ifa_label) &&
                                    sin_orig.sin_addr.s_addr ==
@@ -1062,7 +1087,8 @@ int devinet_ioctl(struct net *net, unsigned int cmd, struct ifreq *ifr)
                   4.3BSD-style and passed in junk so we fall back to
                   comparing just the label */
                if (!ifa) {
-                       for (ifap = &in_dev->ifa_list; (ifa = *ifap) != NULL;
+                       for (ifap = &in_dev->ifa_list;
+                            (ifa = rtnl_dereference(*ifap)) != NULL;
                             ifap = &ifa->ifa_next)
                                if (!strcmp(ifr->ifr_name, ifa->ifa_label))
                                        break;