ftrace: If the hash for a probe fails to update then free what was initialized

If the ftrace_hash_move_and_update_ops() fails, and an ops->free() function
exists, then it needs to be called on all the ops that were added by this
registration.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

1 files changed, 15 insertions, 1 deletions

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 493c7ff7e860..8394055e6793 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -4003,7 +4003,7 @@ register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
         ret = ftrace_hash_move_and_update_ops(&ops->ops, orig_hash,
                                                       hash, 1);
         if (ret < 0)
-                goto out_unlock;
+                goto err_unlock;
 
         if (list_empty(&ops->list))
                 list_add(&ops->list, &ftrace_func_probes);
@@ -4021,6 +4021,20 @@ register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
         free_ftrace_hash(hash);
 
         return ret;
+
+ err_unlock:
+        if (!ops->free)
+                goto out_unlock;
+
+        /* Failed to do the move, need to call the free functions */
+        for (i = 0; i < size; i++) {
+                hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
+                        if (ftrace_lookup_ip(old_hash, entry->ip))
+                                continue;
+                        ops->free(ops, entry->ip, NULL);
+                }
+        }
+        goto out_unlock;
 }
 
 int