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-rw-r--r--kernel/trace/trace_events.c144
1 files changed, 101 insertions, 43 deletions
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index d128f65778e6..f2f5064701e5 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -93,9 +93,7 @@ int trace_define_common_fields(struct ftrace_event_call *call)
}
EXPORT_SYMBOL_GPL(trace_define_common_fields);
-#ifdef CONFIG_MODULES
-
-static void trace_destroy_fields(struct ftrace_event_call *call)
+void trace_destroy_fields(struct ftrace_event_call *call)
{
struct ftrace_event_field *field, *next;
@@ -107,8 +105,6 @@ static void trace_destroy_fields(struct ftrace_event_call *call)
}
}
-#endif /* CONFIG_MODULES */
-
static void ftrace_event_enable_disable(struct ftrace_event_call *call,
int enable)
{
@@ -117,14 +113,14 @@ static void ftrace_event_enable_disable(struct ftrace_event_call *call,
if (call->enabled) {
call->enabled = 0;
tracing_stop_cmdline_record();
- call->unregfunc(call->data);
+ call->unregfunc(call);
}
break;
case 1:
if (!call->enabled) {
call->enabled = 1;
tracing_start_cmdline_record();
- call->regfunc(call->data);
+ call->regfunc(call);
}
break;
}
@@ -938,27 +934,46 @@ event_create_dir(struct ftrace_event_call *call, struct dentry *d_events,
return 0;
}
-#define for_each_event(event, start, end) \
- for (event = start; \
- (unsigned long)event < (unsigned long)end; \
- event++)
+static int __trace_add_event_call(struct ftrace_event_call *call)
+{
+ struct dentry *d_events;
+ int ret;
-#ifdef CONFIG_MODULES
+ if (!call->name)
+ return -EINVAL;
-static LIST_HEAD(ftrace_module_file_list);
+ if (call->raw_init) {
+ ret = call->raw_init(call);
+ if (ret < 0) {
+ if (ret != -ENOSYS)
+ pr_warning("Could not initialize trace "
+ "events/%s\n", call->name);
+ return ret;
+ }
+ }
-/*
- * Modules must own their file_operations to keep up with
- * reference counting.
- */
-struct ftrace_module_file_ops {
- struct list_head list;
- struct module *mod;
- struct file_operations id;
- struct file_operations enable;
- struct file_operations format;
- struct file_operations filter;
-};
+ d_events = event_trace_events_dir();
+ if (!d_events)
+ return -ENOENT;
+
+ ret = event_create_dir(call, d_events, &ftrace_event_id_fops,
+ &ftrace_enable_fops, &ftrace_event_filter_fops,
+ &ftrace_event_format_fops);
+ if (!ret)
+ list_add(&call->list, &ftrace_events);
+
+ return ret;
+}
+
+/* Add an additional event_call dynamically */
+int trace_add_event_call(struct ftrace_event_call *call)
+{
+ int ret;
+ mutex_lock(&event_mutex);
+ ret = __trace_add_event_call(call);
+ mutex_unlock(&event_mutex);
+ return ret;
+}
static void remove_subsystem_dir(const char *name)
{
@@ -986,6 +1001,53 @@ static void remove_subsystem_dir(const char *name)
}
}
+/*
+ * Must be called under locking both of event_mutex and trace_event_mutex.
+ */
+static void __trace_remove_event_call(struct ftrace_event_call *call)
+{
+ ftrace_event_enable_disable(call, 0);
+ if (call->event)
+ __unregister_ftrace_event(call->event);
+ debugfs_remove_recursive(call->dir);
+ list_del(&call->list);
+ trace_destroy_fields(call);
+ destroy_preds(call);
+ remove_subsystem_dir(call->system);
+}
+
+/* Remove an event_call */
+void trace_remove_event_call(struct ftrace_event_call *call)
+{
+ mutex_lock(&event_mutex);
+ down_write(&trace_event_mutex);
+ __trace_remove_event_call(call);
+ up_write(&trace_event_mutex);
+ mutex_unlock(&event_mutex);
+}
+
+#define for_each_event(event, start, end) \
+ for (event = start; \
+ (unsigned long)event < (unsigned long)end; \
+ event++)
+
+#ifdef CONFIG_MODULES
+
+static LIST_HEAD(ftrace_module_file_list);
+
+/*
+ * Modules must own their file_operations to keep up with
+ * reference counting.
+ */
+struct ftrace_module_file_ops {
+ struct list_head list;
+ struct module *mod;
+ struct file_operations id;
+ struct file_operations enable;
+ struct file_operations format;
+ struct file_operations filter;
+};
+
static struct ftrace_module_file_ops *
trace_create_file_ops(struct module *mod)
{
@@ -1043,7 +1105,7 @@ static void trace_module_add_events(struct module *mod)
if (!call->name)
continue;
if (call->raw_init) {
- ret = call->raw_init();
+ ret = call->raw_init(call);
if (ret < 0) {
if (ret != -ENOSYS)
pr_warning("Could not initialize trace "
@@ -1061,10 +1123,11 @@ static void trace_module_add_events(struct module *mod)
return;
}
call->mod = mod;
- list_add(&call->list, &ftrace_events);
- event_create_dir(call, d_events,
- &file_ops->id, &file_ops->enable,
- &file_ops->filter, &file_ops->format);
+ ret = event_create_dir(call, d_events,
+ &file_ops->id, &file_ops->enable,
+ &file_ops->filter, &file_ops->format);
+ if (!ret)
+ list_add(&call->list, &ftrace_events);
}
}
@@ -1078,14 +1141,7 @@ static void trace_module_remove_events(struct module *mod)
list_for_each_entry_safe(call, p, &ftrace_events, list) {
if (call->mod == mod) {
found = true;
- ftrace_event_enable_disable(call, 0);
- if (call->event)
- __unregister_ftrace_event(call->event);
- debugfs_remove_recursive(call->dir);
- list_del(&call->list);
- trace_destroy_fields(call);
- destroy_preds(call);
- remove_subsystem_dir(call->system);
+ __trace_remove_event_call(call);
}
}
@@ -1203,7 +1259,7 @@ static __init int event_trace_init(void)
if (!call->name)
continue;
if (call->raw_init) {
- ret = call->raw_init();
+ ret = call->raw_init(call);
if (ret < 0) {
if (ret != -ENOSYS)
pr_warning("Could not initialize trace "
@@ -1211,10 +1267,12 @@ static __init int event_trace_init(void)
continue;
}
}
- list_add(&call->list, &ftrace_events);
- event_create_dir(call, d_events, &ftrace_event_id_fops,
- &ftrace_enable_fops, &ftrace_event_filter_fops,
- &ftrace_event_format_fops);
+ ret = event_create_dir(call, d_events, &ftrace_event_id_fops,
+ &ftrace_enable_fops,
+ &ftrace_event_filter_fops,
+ &ftrace_event_format_fops);
+ if (!ret)
+ list_add(&call->list, &ftrace_events);
}
while (true) {

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