tracing/kprobes: Reject new event if loc is NULL

Reject the new event which has NULL location for kprobes. For kprobes, user must specify at least the location. Link: http://lkml.kernel.org/r/158779376597.6082.1411212055469099461.stgit@devnote2 Cc: Tom Zanussi <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: [email protected] Fixes: 2a588dd ("tracing: Add kprobe event command generation functions") Signed-off-by: Masami Hiramatsu <[email protected]> Signed-off-by: Steven Rostedt (VMware) <[email protected]>
soumdtt · May 6, 2020 · 5b4dcd2 · 5b4dcd2
1 parent da0f1f4
commit 5b4dcd2
Showing 1 changed file with 6 additions and 0 deletions.
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
@@ -940,6 +940,9 @@ EXPORT_SYMBOL_GPL(kprobe_event_cmd_init);
  * complete command or only the first part of it; in the latter case,
  * kprobe_event_add_fields() can be used to add more fields following this.
  *
+ * Unlikely the synth_event_gen_cmd_start(), @loc must be specified. This
+ * returns -EINVAL if @loc == NULL.
+ *
  * Return: 0 if successful, error otherwise.
  */
 int __kprobe_event_gen_cmd_start(struct dynevent_cmd *cmd, bool kretprobe,
@@ -953,6 +956,9 @@ int __kprobe_event_gen_cmd_start(struct dynevent_cmd *cmd, bool kretprobe,
 	if (cmd->type != DYNEVENT_TYPE_KPROBE)
 		return -EINVAL;
 
+	if (!loc)
+		return -EINVAL;
+
 	if (kretprobe)
 		snprintf(buf, MAX_EVENT_NAME_LEN, "r:kprobes/%s", name);
 	else