tracepoints: use modules notifiers

Impact: cleanup

Use module notifiers for tracepoint updates rather than adding a hook in
module.c.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/kernel/module.c b/kernel/module.c
index 72c6ca5..fc1dff9 100644 (file)
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -2187,11 +2187,6 @@ static noinline struct module *load_module(void __user *umod,
                debug = section_objs(hdr, sechdrs, secstrings, "__verbose",
                                     sizeof(*debug), &num_debug);
                dynamic_printk_setup(debug, num_debug);
-
-#ifdef CONFIG_TRACEPOINTS
-               tracepoint_update_probe_range(mod->tracepoints,
-                       mod->tracepoints + mod->num_tracepoints);
-#endif
        }
 
        /* sechdrs[0].sh_size is always zero */

diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c
index 47a7303..94ac4e3 100644 (file)
--- a/kernel/tracepoint.c
+++ b/kernel/tracepoint.c
@@ -541,3 +541,32 @@ void tracepoint_iter_reset(struct tracepoint_iter *iter)
        iter->tracepoint = NULL;
 }
 EXPORT_SYMBOL_GPL(tracepoint_iter_reset);
+
+int tracepoint_module_notify(struct notifier_block *self,
+                            unsigned long val, void *data)
+{
+       struct module *mod = data;
+
+       switch (val) {
+       case MODULE_STATE_COMING:
+               tracepoint_update_probe_range(mod->tracepoints,
+                       mod->tracepoints + mod->num_tracepoints);
+               break;
+       case MODULE_STATE_GOING:
+               tracepoint_update_probe_range(mod->tracepoints,
+                       mod->tracepoints + mod->num_tracepoints);
+               break;
+       }
+       return 0;
+}
+
+struct notifier_block tracepoint_module_nb = {
+       .notifier_call = tracepoint_module_notify,
+       .priority = 0,
+};
+
+static int init_tracepoints(void)
+{
+       return register_module_notifier(&tracepoint_module_nb);
+}
+__initcall(init_tracepoints);