1 // SPDX-License-Identifier: GPL-2.0-only
2 #include <linux/module.h>
4 #include <linux/mm.h> /* for handle_mm_fault() */
5 #include <linux/ftrace.h>
7 void my_direct_func(struct vm_area_struct *vma,
8 unsigned long address, unsigned int flags)
10 trace_printk("handle mm fault vma=%p address=%lx flags=%x\n",
14 extern void my_tramp(void *);
17 " .pushsection .text, \"ax\", @progbits\n"
18 " .type my_tramp, @function\n"
25 " call my_direct_func\n"
31 " .size my_tramp, .-my_tramp\n"
36 static int __init ftrace_direct_init(void)
38 return register_ftrace_direct((unsigned long)handle_mm_fault,
39 (unsigned long)my_tramp);
42 static void __exit ftrace_direct_exit(void)
44 unregister_ftrace_direct((unsigned long)handle_mm_fault,
45 (unsigned long)my_tramp);
48 module_init(ftrace_direct_init);
49 module_exit(ftrace_direct_exit);
51 MODULE_AUTHOR("Steven Rostedt");
52 MODULE_DESCRIPTION("Another example use case of using register_ftrace_direct()");
53 MODULE_LICENSE("GPL");