Merge branch 'linux-4.12' of git://github.com/skeggsb/linux into drm-next

[sfrench/cifs-2.6.git] / net / netfilter / nf_conntrack_helper.c

diff --git a/net/netfilter/nf_conntrack_helper.c b/net/netfilter/nf_conntrack_helper.c
index 6dc44d9b41900bea12f487e5a044259e92a47f7e..4eeb3418366ad5473945395346b6e4e5fc213fbc 100644 (file)
--- a/net/netfilter/nf_conntrack_helper.c
+++ b/net/netfilter/nf_conntrack_helper.c
@@ -158,16 +158,25 @@ nf_conntrack_helper_try_module_get(const char *name, u16 l3num, u8 protonum)
 {
        struct nf_conntrack_helper *h;
 
+       rcu_read_lock();
+
        h = __nf_conntrack_helper_find(name, l3num, protonum);
 #ifdef CONFIG_MODULES
        if (h == NULL) {
-               if (request_module("nfct-helper-%s", name) == 0)
+               rcu_read_unlock();
+               if (request_module("nfct-helper-%s", name) == 0) {
+                       rcu_read_lock();
                        h = __nf_conntrack_helper_find(name, l3num, protonum);
+               } else {
+                       return h;
+               }
        }
 #endif
        if (h != NULL && !try_module_get(h->me))
                h = NULL;
 
+       rcu_read_unlock();
+
        return h;
 }
 EXPORT_SYMBOL_GPL(nf_conntrack_helper_try_module_get);
@@ -311,38 +320,36 @@ void nf_ct_helper_expectfn_unregister(struct nf_ct_helper_expectfn *n)
 }
 EXPORT_SYMBOL_GPL(nf_ct_helper_expectfn_unregister);
 
+/* Caller should hold the rcu lock */
 struct nf_ct_helper_expectfn *
 nf_ct_helper_expectfn_find_by_name(const char *name)
 {
        struct nf_ct_helper_expectfn *cur;
        bool found = false;
 
-       rcu_read_lock();
        list_for_each_entry_rcu(cur, &nf_ct_helper_expectfn_list, head) {
                if (!strcmp(cur->name, name)) {
                        found = true;
                        break;
                }
        }
-       rcu_read_unlock();
        return found ? cur : NULL;
 }
 EXPORT_SYMBOL_GPL(nf_ct_helper_expectfn_find_by_name);
 
+/* Caller should hold the rcu lock */
 struct nf_ct_helper_expectfn *
 nf_ct_helper_expectfn_find_by_symbol(const void *symbol)
 {
        struct nf_ct_helper_expectfn *cur;
        bool found = false;
 
-       rcu_read_lock();
        list_for_each_entry_rcu(cur, &nf_ct_helper_expectfn_list, head) {
                if (cur->expectfn == symbol) {
                        found = true;
                        break;
                }
        }
-       rcu_read_unlock();
        return found ? cur : NULL;
 }
 EXPORT_SYMBOL_GPL(nf_ct_helper_expectfn_find_by_symbol);