3 files changed, 35 insertions, 10 deletions

diff --git a/net/dccp/ccid.c b/net/dccp/ccid.c
index 330372a1a0b6..e3fb52b4f5c6 100644
--- a/net/dccp/ccid.c
+++ b/net/dccp/ccid.c
@@ -196,22 +196,41 @@ int ccid_unregister(struct ccid_operations *ccid_ops)
 
 EXPORT_SYMBOL_GPL(ccid_unregister);
 
+/**
+ * ccid_request_module  -  Pre-load CCID module for later use
+ * This should be called only from process context (e.g. during connection
+ * setup) and is necessary for later calls to ccid_new (typically in software
+ * interrupt), so that it has the modules available when they are needed.
+ */
+static int ccid_request_module(u8 id)
+{
+        if (!in_atomic()) {
+                ccids_read_lock();
+                if (ccids[id] == NULL) {
+                        ccids_read_unlock();
+                        return request_module("net-dccp-ccid-%d", id);
+                }
+                ccids_read_unlock();
+        }
+        return 0;
+}
+
+int ccid_request_modules(u8 const *ccid_array, u8 array_len)
+{
+#ifdef CONFIG_KMOD
+        while (array_len--)
+                if (ccid_request_module(ccid_array[array_len]))
+                        return -1;
+#endif
+        return 0;
+}
+
 struct ccid *ccid_new(unsigned char id, struct sock *sk, int rx, gfp_t gfp)
 {
         struct ccid_operations *ccid_ops;
         struct ccid *ccid = NULL;
 
         ccids_read_lock();
-#ifdef CONFIG_KMOD
-        if (ccids[id] == NULL) {
-                /* We only try to load if in process context */
-                ccids_read_unlock();
-                if (gfp & GFP_ATOMIC)
-                        goto out;
-                request_module("net-dccp-ccid-%d", id);
-                ccids_read_lock();
-        }
-#endif
         ccid_ops = ccids[id];
         if (ccid_ops == NULL)
                 goto out_unlock;
diff --git a/net/dccp/ccid.h b/net/dccp/ccid.h
index 18f69423a708..20ba066b2775 100644
--- a/net/dccp/ccid.h
+++ b/net/dccp/ccid.h
@@ -108,6 +108,7 @@ extern int  ccid_get_builtin_ccids(u8 **ccid_array, u8 *array_len);
 extern int  ccid_getsockopt_builtin_ccids(struct sock *sk, int len,
                                           char __user *, int __user *);
 
+extern int    ccid_request_modules(u8 const *ccid_array, u8 array_len);
 extern struct ccid *ccid_new(unsigned char id, struct sock *sk, int rx,
                              gfp_t gfp);
 
diff --git a/net/dccp/feat.c b/net/dccp/feat.c
index a687740e4420..9a4938092783 100644
--- a/net/dccp/feat.c
+++ b/net/dccp/feat.c
@@ -1158,6 +1158,11 @@ int dccp_feat_init(struct sock *sk)
             ccid_get_builtin_ccids(&rx.val, &rx.len))
                 return -ENOBUFS;
 
+        /* Pre-load all CCID modules that are going to be advertised */
+        rc = -EUNATCH;
+        if (ccid_request_modules(tx.val, tx.len))
+                goto free_ccid_lists;
+
         if (!dccp_feat_prefer(sysctl_dccp_feat_tx_ccid, tx.val, tx.len) ||
             !dccp_feat_prefer(sysctl_dccp_feat_rx_ccid, rx.val, rx.len))
                 goto free_ccid_lists;