1 files changed, 10 insertions, 1 deletions

diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c
index 0d4ef26574ff..0058f33d05c1 100644
--- a/kernel/tracepoint.c
+++ b/kernel/tracepoint.c
@@ -62,6 +62,7 @@ struct tracepoint_entry {
         struct hlist_node hlist;
         struct tracepoint_func *funcs;
         int refcount;   /* Number of times armed. 0 if disarmed. */
+        int enabled;    /* Tracepoint enabled */
         char name[0];
 };
 
@@ -237,6 +238,7 @@ static struct tracepoint_entry *add_tracepoint(const char *name)
         memcpy(&e->name[0], name, name_len);
         e->funcs = NULL;
         e->refcount = 0;
+        e->enabled = 0;
         hlist_add_head(&e->hlist, head);
         return e;
 }
@@ -316,6 +318,7 @@ static void tracepoint_update_probe_range(struct tracepoint * const *begin,
                 if (mark_entry) {
                         set_tracepoint(&mark_entry, *iter,
                                         !!mark_entry->refcount);
+                        mark_entry->enabled = !!mark_entry->refcount;
                 } else {
                         disable_tracepoint(*iter);
                 }
@@ -380,6 +383,8 @@ tracepoint_add_probe(const char *name, void *probe, void *data)
 int tracepoint_probe_register(const char *name, void *probe, void *data)
 {
         struct tracepoint_func *old;
+        struct tracepoint_entry *entry;
+        int ret = 0;
 
         mutex_lock(&tracepoints_mutex);
         old = tracepoint_add_probe(name, probe, data);
@@ -388,9 +393,13 @@ int tracepoint_probe_register(const char *name, void *probe, void *data)
                 return PTR_ERR(old);
         }
         tracepoint_update_probes();             /* may update entry */
+        entry = get_tracepoint(name);
+        /* Make sure the entry was enabled */
+        if (!entry || !entry->enabled)
+                ret = -ENODEV;
         mutex_unlock(&tracepoints_mutex);
         release_probes(old);
-        return 0;
+        return ret;
 }
 EXPORT_SYMBOL_GPL(tracepoint_probe_register);