[v3,1/5] tracepoint: Support iterating over tracepoints on modules

Commit Message

Masami Hiramatsu (Google) Aug. 18, 2024, 10:42 a.m. UTC

From: Masami Hiramatsu (Google) <[e-mail]>

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).

Signed-off-by: Masami Hiramatsu (Google) <[e-mail]>
---
 Changes in v3:
  - Add kerneldoc for for_each_module_tracepoint.
---
 include/linux/tracepoint.h |    7 +++++++
 kernel/tracepoint.c        |   21 +++++++++++++++++++++
 2 files changed, 28 insertions(+)

Patch

diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index 6be396bb4297..837fcf8ec0d5 100644
--- a/include/linux/tracepoint.h
+++ b/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 */
 
 /*
diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c
index 8d1507dd0724..bed4aad36d92 100644
--- a/kernel/tracepoint.c
+++ b/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 */
 
 /**