1 // SPDX-License-Identifier: GPL-2.0-only
2 #include <linux/module.h>
4 #include <linux/sched.h> /* for wake_up_process() */
5 #include <linux/ftrace.h>
7 void my_direct_func(struct task_struct *p)
9 trace_printk("waking up %s-%d\n", p->comm, p->pid);
12 extern void my_tramp(void *);
15 " .pushsection .text, \"ax\", @progbits\n"
16 " .type my_tramp, @function\n"
22 " call my_direct_func\n"
26 " .size my_tramp, .-my_tramp\n"
31 static int __init ftrace_direct_init(void)
33 return register_ftrace_direct((unsigned long)wake_up_process,
34 (unsigned long)my_tramp);
37 static void __exit ftrace_direct_exit(void)
39 unregister_ftrace_direct((unsigned long)wake_up_process,
40 (unsigned long)my_tramp);
43 module_init(ftrace_direct_init);
44 module_exit(ftrace_direct_exit);
46 MODULE_AUTHOR("Steven Rostedt");
47 MODULE_DESCRIPTION("Example use case of using register_ftrace_direct()");
48 MODULE_LICENSE("GPL");