trace-cmd: Unload plugins on tracecmd_close()

When the handle is freed, we need to unload the plugins, otherwise
we will keep loading them if an app closes and opens a new handle.

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

1 files changed, 37 insertions, 10 deletions

diff --git a/trace-util.c b/trace-util.c
index 7a75056..7d168f9 100644
--- a/trace-util.c
+++ b/trace-util.c
@@ -22,6 +22,11 @@
 # define MAX_PATH 1024
 #endif
 
+struct plugin_list {
+        struct plugin_list      *next;
+        void                    *handle;
+};
+
 void __weak die(char *fmt, ...)
 {
         va_list ap;
@@ -148,12 +153,14 @@ void parse_ftrace_printk(char *file, unsigned int size __unused)
         }
 }
 
-static int load_plugin(struct pevent *pevent,
-                       const char *path, const char *file)
+static struct plugin_list *
+load_plugin(struct pevent *pevent, struct plugin_list *plugin_list,
+            const char *path, const char *file)
 {
+        pevent_plugin_load_func func;
+        struct plugin_list *list;
         char *plugin;
         void *handle;
-        pevent_plugin_load_func func;
         int ret = -1;
 
         plugin = malloc_or_die(strlen(path) + strlen(file) + 2);
@@ -169,6 +176,11 @@ static int load_plugin(struct pevent *pevent,
                 goto out;
         }
 
+        list = malloc_or_die(sizeof(*list));
+        list->next = plugin_list;
+        list->handle = handle;
+        plugin_list = list;
+
         func = dlsym(handle, PEVENT_PLUGIN_LOADER_NAME);
         if (!func) {
                 warning("cound not find func '%s' in plugin '%s'\n%s\n",
@@ -182,8 +194,7 @@ static int load_plugin(struct pevent *pevent,
  out:
         free(plugin);
 
-        /* dlclose ?? */
-        return ret;
+        return plugin_list;
 }
 
 char *tracecmd_find_tracing_dir(void)
@@ -221,8 +232,9 @@ char *tracecmd_find_tracing_dir(void)
         return tracing_dir;
 }
 
-int trace_load_plugins(struct pevent *pevent)
+struct plugin_list *tracecmd_load_plugins(struct pevent *pevent)
 {
+        struct plugin_list *list = NULL;
         struct dirent *dent;
         struct stat st;
         DIR *dir;
@@ -230,11 +242,10 @@ int trace_load_plugins(struct pevent *pevent)
         char *path;
         int ret;
 
-
         home = getenv("HOME");
 
         if (!home)
-                return -1;
+                return NULL;
 
         path = malloc_or_die(strlen(home) + strlen(PLUGIN_DIR) + 2);
 
@@ -260,12 +271,28 @@ int trace_load_plugins(struct pevent *pevent)
                     strcmp(name, "..") == 0)
                         continue;
 
-                load_plugin(pevent, path, name);
+                list = load_plugin(pevent, list, path, name);
         }
 
         closedir(dir);
  fail:
         free(path);
 
-        return -1;
+        return list;
+}
+
+void tracecmd_unload_plugins(struct plugin_list *plugin_list)
+{
+        pevent_plugin_unload_func func;
+        struct plugin_list *list;
+
+        while (plugin_list) {
+                list = plugin_list;
+                plugin_list = list->next;
+                func = dlsym(list->handle, PEVENT_PLUGIN_UNLOADER_NAME);
+                if (func)
+                        func();
+                dlclose(list->handle);
+                free(list);
+        }
 }