libtraceevent: Improve error handling of tep_plugin_add_option() API

In case of memory error, ensure all allocated resources are freed.
Do not append broken option in trace_plugin_options list.

Link: https://lore.kernel.org/r/CAM9d7cizjF+fbK7YzmsBDgrx__4YAOsmEq67D3sWET8FF+YdFA@mail.gmail.com
Link: https://lore.kernel.org/linux-trace-devel/20200714103027.2477584-5-tz.stoyanov@gmail.com
Link: https://lore.kernel.org/linux-trace-devel/20200716092014.2613403-5-tz.stoyanov@gmail.com
Suggested-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: linux-trace-devel@vger.kernel.org
Link: http://lore.kernel.org/lkml/20200722011755.158091410@goodmis.org
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/lib/traceevent/event-plugin.c b/tools/lib/traceevent/event-plugin.c
index f8d253a619706fb3feed67afc97bfa18c34c3410..6b84b9c4e6ba5184d6560d2f4def77260bb2ca2f 100644 (file)
--- a/tools/lib/traceevent/event-plugin.c
+++ b/tools/lib/traceevent/event-plugin.c
@@ -361,23 +361,25 @@ int tep_plugin_add_option(const char *name, const char *val)
        if (!op) {
                op = malloc(sizeof(*op));
                if (!op)
-                       return -ENOMEM;
+                       goto out_free;
                memset(op, 0, sizeof(*op));
-               op->next = trace_plugin_options;
-               trace_plugin_options = op;
-
                op->plugin = plugin;
                op->option = option_str;
-
                if (val) {
                        op->value = strdup(val);
-                       if (!op->value)
+                       if (!op->value) {
+                               free(op);
                                goto out_free;
+                       }
                }
+               op->next = trace_plugin_options;
+               trace_plugin_options = op;
        }
 
        return process_option(plugin, option_str, val);
- out_free:
+
+out_free:
+       free(plugin);
        free(option_str);
        return -ENOMEM;
 }