tracing: Allow for modules to convert their enums to values
Update the infrastructure such that modules that declare TRACE_DEFINE_ENUM()
will have those enums converted into their values in the tracepoint
print fmt strings.
Link: http://lkml.kernel.org/r/87vbhjp74q.fsf@rustcorp.com.au
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/include/linux/module.h b/include/linux/module.h
index 42999fe..53dc41d 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -338,6 +338,8 @@
#ifdef CONFIG_EVENT_TRACING
struct ftrace_event_call **trace_events;
unsigned int num_trace_events;
+ struct trace_enum_map **trace_enums;
+ unsigned int num_trace_enums;
#endif
#ifdef CONFIG_FTRACE_MCOUNT_RECORD
unsigned int num_ftrace_callsites;
diff --git a/kernel/module.c b/kernel/module.c
index b3d634e..d8f8ab2 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -2753,6 +2753,9 @@
mod->trace_events = section_objs(info, "_ftrace_events",
sizeof(*mod->trace_events),
&mod->num_trace_events);
+ mod->trace_enums = section_objs(info, "_ftrace_enum_map",
+ sizeof(*mod->trace_enums),
+ &mod->num_trace_enums);
#endif
#ifdef CONFIG_TRACING
mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt",
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index ebf4964..28e6654 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -3908,11 +3908,9 @@
.write = tracing_saved_cmdlines_size_write,
};
-static void
-trace_insert_enum_map(struct trace_enum_map **start, struct trace_enum_map **stop)
+static void trace_insert_enum_map(struct trace_enum_map **start, int len)
{
struct trace_enum_map **map;
- int len = stop - start;
if (len <= 0)
return;
@@ -6561,9 +6559,48 @@
static void __init trace_enum_init(void)
{
- trace_insert_enum_map(__start_ftrace_enum_maps, __stop_ftrace_enum_maps);
+ int len;
+
+ len = __stop_ftrace_enum_maps - __start_ftrace_enum_maps;
+ trace_insert_enum_map(__start_ftrace_enum_maps, len);
}
+#ifdef CONFIG_MODULES
+static void trace_module_add_enums(struct module *mod)
+{
+ if (!mod->num_trace_enums)
+ return;
+
+ /*
+ * Modules with bad taint do not have events created, do
+ * not bother with enums either.
+ */
+ if (trace_module_has_bad_taint(mod))
+ return;
+
+ trace_insert_enum_map(mod->trace_enums, mod->num_trace_enums);
+}
+
+static int trace_module_notify(struct notifier_block *self,
+ unsigned long val, void *data)
+{
+ struct module *mod = data;
+
+ switch (val) {
+ case MODULE_STATE_COMING:
+ trace_module_add_enums(mod);
+ break;
+ }
+
+ return 0;
+}
+
+static struct notifier_block trace_module_nb = {
+ .notifier_call = trace_module_notify,
+ .priority = 0,
+};
+#endif
+
static __init int tracer_init_debugfs(void)
{
struct dentry *d_tracer;
@@ -6590,6 +6627,10 @@
trace_enum_init();
+#ifdef CONFIG_MODULES
+ register_module_notifier(&trace_module_nb);
+#endif
+
#ifdef CONFIG_DYNAMIC_FTRACE
trace_create_file("dyn_ftrace_total_info", 0444, d_tracer,
&ftrace_update_tot_cnt, &tracing_dyn_info_fops);
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index fc58c50..a576bbe 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -2034,7 +2034,7 @@
static struct notifier_block trace_module_nb = {
.notifier_call = trace_module_notify,
- .priority = 0,
+ .priority = 1, /* higher than trace.c module notify */
};
#endif /* CONFIG_MODULES */