ftrace: Allow for function tracing instance to filter functions
Create a "set_ftrace_filter" and "set_ftrace_notrace" files in the instance
directories to let users filter of functions to trace for the given instance.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 2b3e239..dcee546 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -436,6 +436,9 @@
static int __register_ftrace_function(struct ftrace_ops *ops)
{
+ if (ops->flags & FTRACE_OPS_FL_DELETED)
+ return -EINVAL;
+
if (FTRACE_WARN_ON(ops == &global_ops))
return -EINVAL;
@@ -4112,6 +4115,36 @@
};
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+void ftrace_create_filter_files(struct ftrace_ops *ops,
+ struct dentry *parent)
+{
+
+ trace_create_file("set_ftrace_filter", 0644, parent,
+ ops, &ftrace_filter_fops);
+
+ trace_create_file("set_ftrace_notrace", 0644, parent,
+ ops, &ftrace_notrace_fops);
+}
+
+/*
+ * The name "destroy_filter_files" is really a misnomer. Although
+ * in the future, it may actualy delete the files, but this is
+ * really intended to make sure the ops passed in are disabled
+ * and that when this function returns, the caller is free to
+ * free the ops.
+ *
+ * The "destroy" name is only to match the "create" name that this
+ * should be paired with.
+ */
+void ftrace_destroy_filter_files(struct ftrace_ops *ops)
+{
+ mutex_lock(&ftrace_lock);
+ if (ops->flags & FTRACE_OPS_FL_ENABLED)
+ ftrace_shutdown(ops, 0);
+ ops->flags |= FTRACE_OPS_FL_DELETED;
+ mutex_unlock(&ftrace_lock);
+}
+
static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer)
{
@@ -4121,11 +4154,7 @@
trace_create_file("enabled_functions", 0444,
d_tracer, NULL, &ftrace_enabled_fops);
- trace_create_file("set_ftrace_filter", 0644, d_tracer,
- &global_ops, &ftrace_filter_fops);
-
- trace_create_file("set_ftrace_notrace", 0644, d_tracer,
- &global_ops, &ftrace_notrace_fops);
+ ftrace_create_filter_files(&global_ops, d_tracer);
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
trace_create_file("set_graph_function", 0444, d_tracer,