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-rw-r--r--include/net/ip6_fib.h30
-rw-r--r--net/ipv6/ip6_fib.c20
-rw-r--r--net/ipv6/route.c14
3 files changed, 56 insertions, 8 deletions
diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h
index 1a88008cc6f5..e9c59db92942 100644
--- a/include/net/ip6_fib.h
+++ b/include/net/ip6_fib.h
@@ -70,6 +70,7 @@ struct fib6_node {
__u16 fn_flags;
int fn_sernum;
struct rt6_info *rr_ptr;
+ struct rcu_head rcu;
};
#ifndef CONFIG_IPV6_SUBTREES
@@ -167,13 +168,40 @@ static inline void rt6_update_expires(struct rt6_info *rt0, int timeout)
rt0->rt6i_flags |= RTF_EXPIRES;
}
+/* Function to safely get fn->sernum for passed in rt
+ * and store result in passed in cookie.
+ * Return true if we can get cookie safely
+ * Return false if not
+ */
+static inline bool rt6_get_cookie_safe(const struct rt6_info *rt,
+ u32 *cookie)
+{
+ struct fib6_node *fn;
+ bool status = false;
+
+ rcu_read_lock();
+ fn = rcu_dereference(rt->rt6i_node);
+
+ if (fn) {
+ *cookie = fn->fn_sernum;
+ status = true;
+ }
+
+ rcu_read_unlock();
+ return status;
+}
+
static inline u32 rt6_get_cookie(const struct rt6_info *rt)
{
+ u32 cookie = 0;
+
if (rt->rt6i_flags & RTF_PCPU ||
(unlikely(!list_empty(&rt->rt6i_uncached)) && rt->dst.from))
rt = (struct rt6_info *)(rt->dst.from);
- return rt->rt6i_node ? rt->rt6i_node->fn_sernum : 0;
+ rt6_get_cookie_safe(rt, &cookie);
+
+ return cookie;
}
static inline void ip6_rt_put(struct rt6_info *rt)
diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index 5cc0ea038198..a5ebf86f6be8 100644
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c
@@ -148,11 +148,23 @@ static struct fib6_node *node_alloc(void)
return fn;
}
-static void node_free(struct fib6_node *fn)
+static void node_free_immediate(struct fib6_node *fn)
+{
+ kmem_cache_free(fib6_node_kmem, fn);
+}
+
+static void node_free_rcu(struct rcu_head *head)
{
+ struct fib6_node *fn = container_of(head, struct fib6_node, rcu);
+
kmem_cache_free(fib6_node_kmem, fn);
}
+static void node_free(struct fib6_node *fn)
+{
+ call_rcu(&fn->rcu, node_free_rcu);
+}
+
static void rt6_free_pcpu(struct rt6_info *non_pcpu_rt)
{
int cpu;
@@ -601,9 +613,9 @@ insert_above:
if (!in || !ln) {
if (in)
- node_free(in);
+ node_free_immediate(in);
if (ln)
- node_free(ln);
+ node_free_immediate(ln);
return ERR_PTR(-ENOMEM);
}
@@ -1038,7 +1050,7 @@ int fib6_add(struct fib6_node *root, struct rt6_info *rt,
root, and then (in failure) stale node
in main tree.
*/
- node_free(sfn);
+ node_free_immediate(sfn);
err = PTR_ERR(sn);
goto failure;
}
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 94d6a13d47f0..a9d3564caf49 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1289,7 +1289,9 @@ static void rt6_dst_from_metrics_check(struct rt6_info *rt)
static struct dst_entry *rt6_check(struct rt6_info *rt, u32 cookie)
{
- if (!rt->rt6i_node || (rt->rt6i_node->fn_sernum != cookie))
+ u32 rt_cookie;
+
+ if (!rt6_get_cookie_safe(rt, &rt_cookie) || rt_cookie != cookie)
return NULL;
if (rt6_check_expired(rt))
@@ -1357,8 +1359,14 @@ static void ip6_link_failure(struct sk_buff *skb)
if (rt->rt6i_flags & RTF_CACHE) {
if (dst_hold_safe(&rt->dst))
ip6_del_rt(rt);
- } else if (rt->rt6i_node && (rt->rt6i_flags & RTF_DEFAULT)) {
- rt->rt6i_node->fn_sernum = -1;
+ } else {
+ struct fib6_node *fn;
+
+ rcu_read_lock();
+ fn = rcu_dereference(rt->rt6i_node);
+ if (fn && (rt->rt6i_flags & RTF_DEFAULT))
+ fn->fn_sernum = -1;
+ rcu_read_unlock();
}
}
}