xref: /openbmc/linux/lib/livepatch/test_klp_atomic_replace.c (revision 597473720f4dc69749542bfcfed4a927a43d935e)
1*a2818ee4SJoe Lawrence // SPDX-License-Identifier: GPL-2.0
2*a2818ee4SJoe Lawrence // Copyright (C) 2018 Joe Lawrence <joe.lawrence@redhat.com>
3*a2818ee4SJoe Lawrence 
4*a2818ee4SJoe Lawrence #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
5*a2818ee4SJoe Lawrence 
6*a2818ee4SJoe Lawrence #include <linux/module.h>
7*a2818ee4SJoe Lawrence #include <linux/kernel.h>
8*a2818ee4SJoe Lawrence #include <linux/livepatch.h>
9*a2818ee4SJoe Lawrence 
10*a2818ee4SJoe Lawrence static int replace;
11*a2818ee4SJoe Lawrence module_param(replace, int, 0644);
12*a2818ee4SJoe Lawrence MODULE_PARM_DESC(replace, "replace (default=0)");
13*a2818ee4SJoe Lawrence 
14*a2818ee4SJoe Lawrence #include <linux/seq_file.h>
livepatch_meminfo_proc_show(struct seq_file * m,void * v)15*a2818ee4SJoe Lawrence static int livepatch_meminfo_proc_show(struct seq_file *m, void *v)
16*a2818ee4SJoe Lawrence {
17*a2818ee4SJoe Lawrence 	seq_printf(m, "%s: %s\n", THIS_MODULE->name,
18*a2818ee4SJoe Lawrence 		   "this has been live patched");
19*a2818ee4SJoe Lawrence 	return 0;
20*a2818ee4SJoe Lawrence }
21*a2818ee4SJoe Lawrence 
22*a2818ee4SJoe Lawrence static struct klp_func funcs[] = {
23*a2818ee4SJoe Lawrence 	{
24*a2818ee4SJoe Lawrence 		.old_name = "meminfo_proc_show",
25*a2818ee4SJoe Lawrence 		.new_func = livepatch_meminfo_proc_show,
26*a2818ee4SJoe Lawrence 	}, {}
27*a2818ee4SJoe Lawrence };
28*a2818ee4SJoe Lawrence 
29*a2818ee4SJoe Lawrence static struct klp_object objs[] = {
30*a2818ee4SJoe Lawrence 	{
31*a2818ee4SJoe Lawrence 		/* name being NULL means vmlinux */
32*a2818ee4SJoe Lawrence 		.funcs = funcs,
33*a2818ee4SJoe Lawrence 	}, {}
34*a2818ee4SJoe Lawrence };
35*a2818ee4SJoe Lawrence 
36*a2818ee4SJoe Lawrence static struct klp_patch patch = {
37*a2818ee4SJoe Lawrence 	.mod = THIS_MODULE,
38*a2818ee4SJoe Lawrence 	.objs = objs,
39*a2818ee4SJoe Lawrence 	/* set .replace in the init function below for demo purposes */
40*a2818ee4SJoe Lawrence };
41*a2818ee4SJoe Lawrence 
test_klp_atomic_replace_init(void)42*a2818ee4SJoe Lawrence static int test_klp_atomic_replace_init(void)
43*a2818ee4SJoe Lawrence {
44*a2818ee4SJoe Lawrence 	patch.replace = replace;
45*a2818ee4SJoe Lawrence 	return klp_enable_patch(&patch);
46*a2818ee4SJoe Lawrence }
47*a2818ee4SJoe Lawrence 
test_klp_atomic_replace_exit(void)48*a2818ee4SJoe Lawrence static void test_klp_atomic_replace_exit(void)
49*a2818ee4SJoe Lawrence {
50*a2818ee4SJoe Lawrence }
51*a2818ee4SJoe Lawrence 
52*a2818ee4SJoe Lawrence module_init(test_klp_atomic_replace_init);
53*a2818ee4SJoe Lawrence module_exit(test_klp_atomic_replace_exit);
54*a2818ee4SJoe Lawrence MODULE_LICENSE("GPL");
55*a2818ee4SJoe Lawrence MODULE_INFO(livepatch, "Y");
56*a2818ee4SJoe Lawrence MODULE_AUTHOR("Joe Lawrence <joe.lawrence@redhat.com>");
57*a2818ee4SJoe Lawrence MODULE_DESCRIPTION("Livepatch test: atomic replace");
58