Fix ftrace support

[lttng-modules.git] / wrapper / ftrace.h

diff --git a/wrapper/ftrace.h b/wrapper/ftrace.h
new file mode 100644 (file)
index 0000000..4401469
--- /dev/null
+++ b/wrapper/ftrace.h
@@ -0,0 +1,70 @@
+#ifndef _LTT_WRAPPER_FTRACE_H
+#define _LTT_WRAPPER_FTRACE_H
+
+/*
+ * Copyright (C) 2011 Mathieu Desnoyers (mathieu.desnoyers@efficios.com)
+ *
+ * wrapper around vmalloc_sync_all. Using KALLSYMS to get its address when
+ * available, else we need to have a kernel that exports this function to GPL
+ * modules.
+ *
+ * Dual LGPL v2.1/GPL v2 license.
+ */
+
+#include <linux/ftrace.h>
+
+#ifdef CONFIG_KALLSYMS
+
+#include <linux/kallsyms.h>
+
+static inline
+int wrapper_register_ftrace_function_probe(char *glob,
+               struct ftrace_probe_ops *ops, void *data)
+{
+       int (*register_ftrace_function_probe_sym)(char *glob,
+                       struct ftrace_probe_ops *ops, void *data);
+
+       register_ftrace_function_probe_sym = (void *) kallsyms_lookup_name("register_ftrace_function_probe_sym");
+       if (register_ftrace_function_probe_sym) {
+               return register_ftrace_function_probe_sym(glob, ops, data);
+       } else {
+               printk(KERN_WARNING "LTTng: register_ftrace_function_probe symbol lookup failed.\n");
+               return -EINVAL;
+       }
+}
+
+static inline
+void wrapper_unregister_ftrace_function_probe(char *glob,
+               struct ftrace_probe_ops *ops, void *data)
+{
+       void (*unregister_ftrace_function_probe_sym)(char *glob,
+                       struct ftrace_probe_ops *ops, void *data);
+
+       unregister_ftrace_function_probe_sym = (void *) kallsyms_lookup_name("unregister_ftrace_function_probe_sym");
+       if (unregister_ftrace_function_probe_sym) {
+               unregister_ftrace_function_probe_sym(glob, ops, data);
+       } else {
+               printk(KERN_WARNING "LTTng: unregister_ftrace_function_probe symbol lookup failed.\n");
+               WARN_ON(1);
+       }
+}
+
+#else
+
+static inline
+int wrapper_register_ftrace_function_probe(char *glob,
+               struct ftrace_probe_ops *ops, void *data);
+
+{
+       return unregister_ftrace_function_probe();
+}
+
+static inline
+void wrapper_unregister_ftrace_function_probe(char *glob,
+               struct ftrace_probe_ops *ops, void *data);
+{
+       return unregister_ftrace_function_probe();
+}
+#endif
+
+#endif /* _LTT_WRAPPER_FTRACE_H */