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>

2 files changed, 29 insertions, 5 deletions

diff --git a/kernel/module.c b/kernel/module.c
index 72c6ca574211..fc1dff9a178c 100644
--- 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 47a7303d6cd9..94ac4e35530d 100644
--- 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);