blob: 3f0079c9bd6fa2bb99e303731d34911b4f8f035f (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
|
// SPDX-License-Identifier: GPL-2.0-only
#include <linux/module.h>
#include <linux/mm.h> /* for handle_mm_fault() */
#include <linux/ftrace.h>
void my_direct_func(struct vm_area_struct *vma,
unsigned long address, unsigned int flags)
{
trace_printk("handle mm fault vma=%p address=%lx flags=%x\n",
vma, address, flags);
}
extern void my_tramp(void *);
asm (
" .pushsection .text, \"ax\", @progbits\n"
" .type my_tramp, @function\n"
" .globl my_tramp\n"
" my_tramp:"
" pushq %rbp\n"
" movq %rsp, %rbp\n"
" pushq %rdi\n"
" pushq %rsi\n"
" pushq %rdx\n"
" call my_direct_func\n"
" popq %rdx\n"
" popq %rsi\n"
" popq %rdi\n"
" leave\n"
" ret\n"
" .size my_tramp, .-my_tramp\n"
" .popsection\n"
);
static int __init ftrace_direct_init(void)
{
return register_ftrace_direct((unsigned long)handle_mm_fault,
(unsigned long)my_tramp);
}
static void __exit ftrace_direct_exit(void)
{
unregister_ftrace_direct((unsigned long)handle_mm_fault,
(unsigned long)my_tramp);
}
module_init(ftrace_direct_init);
module_exit(ftrace_direct_exit);
MODULE_AUTHOR("Steven Rostedt");
MODULE_DESCRIPTION("Another example use case of using register_ftrace_direct()");
MODULE_LICENSE("GPL");
|
