Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
livepatch/klp-build: Add stub init code for livepatch modules
Add a module initialization stub which can be linked with binary diff
objects to produce a livepatch module.
Acked-by: Petr Mladek <pmladek@suse.com>
Tested-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
+108
+108
scripts/livepatch/init.c
+108
scripts/livepatch/init.c
···
1
+
// SPDX-License-Identifier: GPL-2.0
2
+
/*
3
+
* Init code for a livepatch kernel module
4
+
*/
5
+
6
+
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
7
+
8
+
#include <linux/kernel.h>
9
+
#include <linux/slab.h>
10
+
#include <linux/livepatch.h>
11
+
12
+
extern struct klp_object_ext __start_klp_objects[];
13
+
extern struct klp_object_ext __stop_klp_objects[];
14
+
15
+
static struct klp_patch *patch;
16
+
17
+
static int __init livepatch_mod_init(void)
18
+
{
19
+
struct klp_object *objs;
20
+
unsigned int nr_objs;
21
+
int ret;
22
+
23
+
nr_objs = __stop_klp_objects - __start_klp_objects;
24
+
25
+
if (!nr_objs) {
26
+
pr_err("nothing to patch!\n");
27
+
ret = -EINVAL;
28
+
goto err;
29
+
}
30
+
31
+
patch = kzalloc(sizeof(*patch), GFP_KERNEL);
32
+
if (!patch) {
33
+
ret = -ENOMEM;
34
+
goto err;
35
+
}
36
+
37
+
objs = kzalloc(sizeof(struct klp_object) * (nr_objs + 1), GFP_KERNEL);
38
+
if (!objs) {
39
+
ret = -ENOMEM;
40
+
goto err_free_patch;
41
+
}
42
+
43
+
for (int i = 0; i < nr_objs; i++) {
44
+
struct klp_object_ext *obj_ext = __start_klp_objects + i;
45
+
struct klp_func_ext *funcs_ext = obj_ext->funcs;
46
+
unsigned int nr_funcs = obj_ext->nr_funcs;
47
+
struct klp_func *funcs = objs[i].funcs;
48
+
struct klp_object *obj = objs + i;
49
+
50
+
funcs = kzalloc(sizeof(struct klp_func) * (nr_funcs + 1), GFP_KERNEL);
51
+
if (!funcs) {
52
+
ret = -ENOMEM;
53
+
for (int j = 0; j < i; j++)
54
+
kfree(objs[i].funcs);
55
+
goto err_free_objs;
56
+
}
57
+
58
+
for (int j = 0; j < nr_funcs; j++) {
59
+
funcs[j].old_name = funcs_ext[j].old_name;
60
+
funcs[j].new_func = funcs_ext[j].new_func;
61
+
funcs[j].old_sympos = funcs_ext[j].sympos;
62
+
}
63
+
64
+
obj->name = obj_ext->name;
65
+
obj->funcs = funcs;
66
+
67
+
memcpy(&obj->callbacks, &obj_ext->callbacks, sizeof(struct klp_callbacks));
68
+
}
69
+
70
+
patch->mod = THIS_MODULE;
71
+
patch->objs = objs;
72
+
73
+
/* TODO patch->states */
74
+
75
+
#ifdef KLP_NO_REPLACE
76
+
patch->replace = false;
77
+
#else
78
+
patch->replace = true;
79
+
#endif
80
+
81
+
return klp_enable_patch(patch);
82
+
83
+
err_free_objs:
84
+
kfree(objs);
85
+
err_free_patch:
86
+
kfree(patch);
87
+
err:
88
+
return ret;
89
+
}
90
+
91
+
static void __exit livepatch_mod_exit(void)
92
+
{
93
+
unsigned int nr_objs;
94
+
95
+
nr_objs = __stop_klp_objects - __start_klp_objects;
96
+
97
+
for (int i = 0; i < nr_objs; i++)
98
+
kfree(patch->objs[i].funcs);
99
+
100
+
kfree(patch->objs);
101
+
kfree(patch);
102
+
}
103
+
104
+
module_init(livepatch_mod_init);
105
+
module_exit(livepatch_mod_exit);
106
+
MODULE_LICENSE("GPL");
107
+
MODULE_INFO(livepatch, "Y");
108
+
MODULE_DESCRIPTION("Livepatch module");