tracepoint: Support iterating over tracepoints on modules

Add for_each_module_tracepoint() for iterating over tracepoints
on modules. This is similar to the for_each_kernel_tracepoint()
but only for the tracepoints on modules (not including kernel
built-in tracepoints).

Link: https://lore.kernel.org/all/172397777800.286558.14554748203446214056.stgit@devnote2/Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>

include/linux/tracepoint.h

@@ -64,6 +64,8 @@ struct tp_module {
 bool trace_module_has_bad_taint(struct module *mod);
 extern int register_tracepoint_module_notifier(struct notifier_block *nb);
 extern int unregister_tracepoint_module_notifier(struct notifier_block *nb);
+void for_each_module_tracepoint(void (*fct)(struct tracepoint *, void *),
+				void *priv);
 #else
 static inline bool trace_module_has_bad_taint(struct module *mod)
 {
@@ -79,6 +81,11 @@ int unregister_tracepoint_module_notifier(struct notifier_block *nb)
 {
 	return 0;
 }
+static inline
+void for_each_module_tracepoint(void (*fct)(struct tracepoint *, void *),
+				void *priv)
+{
+}
 #endif /* CONFIG_MODULES */
 
 /*

kernel/tracepoint.c

@@ -735,6 +735,27 @@ static __init int init_tracepoints(void)
 	return ret;
 }
 __initcall(init_tracepoints);
+
+/**
+ * for_each_module_tracepoint - iteration on all tracepoints in all modules
+ * @fct: callback
+ * @priv: private data
+ */
+void for_each_module_tracepoint(void (*fct)(struct tracepoint *tp, void *priv),
+				void *priv)
+{
+	struct tp_module *tp_mod;
+	struct module *mod;
+
+	mutex_lock(&tracepoint_module_list_mutex);
+	list_for_each_entry(tp_mod, &tracepoint_module_list, list) {
+		mod = tp_mod->mod;
+		for_each_tracepoint_range(mod->tracepoints_ptrs,
+			mod->tracepoints_ptrs + mod->num_tracepoints,
+			fct, priv);
+	}
+	mutex_unlock(&tracepoint_module_list_mutex);
+}
 #endif /* CONFIG_MODULES */
 
 /**