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Seth Jenningsb700e7f2014-12-16 11:58:19 -06001/*
2 * livepatch.h - Kernel Live Patching Core
3 *
4 * Copyright (C) 2014 Seth Jennings <sjenning@redhat.com>
5 * Copyright (C) 2014 SUSE
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version 2
10 * of the License, or (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, see <http://www.gnu.org/licenses/>.
19 */
20
21#ifndef _LINUX_LIVEPATCH_H_
22#define _LINUX_LIVEPATCH_H_
23
24#include <linux/module.h>
25#include <linux/ftrace.h>
26
Jessica Yu7e545d62016-03-16 20:55:39 -040027#if IS_ENABLED(CONFIG_LIVEPATCH)
28
Seth Jenningsb700e7f2014-12-16 11:58:19 -060029#include <asm/livepatch.h>
30
Seth Jenningsb700e7f2014-12-16 11:58:19 -060031/**
32 * struct klp_func - function structure for live patching
33 * @old_name: name of the function to be patched
34 * @new_func: pointer to the patched function code
Chris J Argesb2b018e2015-12-01 20:40:54 -060035 * @old_sympos: a hint indicating which symbol position the old function
36 * can be found (optional)
37 * @old_addr: the address of the function being patched
Seth Jenningsb700e7f2014-12-16 11:58:19 -060038 * @kobj: kobject for sysfs resources
Josh Poimboeuf3c33f5b2015-01-20 09:26:19 -060039 * @stack_node: list node for klp_ops func_stack list
Josh Poimboeuff5e547f2017-02-13 19:42:39 -060040 * @old_size: size of the old function
41 * @new_size: size of the new function
Josh Poimboeuf0dade9f2017-02-13 19:42:35 -060042 * @patched: the func has been added to the klp_ops list
Seth Jenningsb700e7f2014-12-16 11:58:19 -060043 */
44struct klp_func {
45 /* external */
46 const char *old_name;
47 void *new_func;
48 /*
Chris J Argesb2b018e2015-12-01 20:40:54 -060049 * The old_sympos field is optional and can be used to resolve
50 * duplicate symbol names in livepatch objects. If this field is zero,
51 * it is expected the symbol is unique, otherwise patching fails. If
52 * this value is greater than zero then that occurrence of the symbol
53 * in kallsyms for the given object is used.
Seth Jenningsb700e7f2014-12-16 11:58:19 -060054 */
Chris J Argesb2b018e2015-12-01 20:40:54 -060055 unsigned long old_sympos;
Seth Jenningsb700e7f2014-12-16 11:58:19 -060056
57 /* internal */
Chris J Argesb2b018e2015-12-01 20:40:54 -060058 unsigned long old_addr;
Seth Jenningsb700e7f2014-12-16 11:58:19 -060059 struct kobject kobj;
Josh Poimboeuf3c33f5b2015-01-20 09:26:19 -060060 struct list_head stack_node;
Josh Poimboeuff5e547f2017-02-13 19:42:39 -060061 unsigned long old_size, new_size;
Josh Poimboeuf0dade9f2017-02-13 19:42:35 -060062 bool patched;
Seth Jenningsb700e7f2014-12-16 11:58:19 -060063};
64
65/**
Seth Jenningsb700e7f2014-12-16 11:58:19 -060066 * struct klp_object - kernel object structure for live patching
67 * @name: module name (or NULL for vmlinux)
Seth Jenningsb700e7f2014-12-16 11:58:19 -060068 * @funcs: function entries for functions to be patched in the object
69 * @kobj: kobject for sysfs resources
70 * @mod: kernel module associated with the patched object
71 * (NULL for vmlinux)
Josh Poimboeuf0dade9f2017-02-13 19:42:35 -060072 * @patched: the object's funcs have been added to the klp_ops list
Seth Jenningsb700e7f2014-12-16 11:58:19 -060073 */
74struct klp_object {
75 /* external */
76 const char *name;
Seth Jenningsb700e7f2014-12-16 11:58:19 -060077 struct klp_func *funcs;
78
79 /* internal */
Miroslav Benescad706d2015-05-19 12:01:18 +020080 struct kobject kobj;
Seth Jenningsb700e7f2014-12-16 11:58:19 -060081 struct module *mod;
Josh Poimboeuf0dade9f2017-02-13 19:42:35 -060082 bool patched;
Seth Jenningsb700e7f2014-12-16 11:58:19 -060083};
84
85/**
86 * struct klp_patch - patch structure for live patching
87 * @mod: reference to the live patch module
88 * @objs: object entries for kernel objects to be patched
89 * @list: list node for global list of registered patches
90 * @kobj: kobject for sysfs resources
Josh Poimboeuf0dade9f2017-02-13 19:42:35 -060091 * @enabled: the patch is enabled (but operation may be incomplete)
Seth Jenningsb700e7f2014-12-16 11:58:19 -060092 */
93struct klp_patch {
94 /* external */
95 struct module *mod;
96 struct klp_object *objs;
97
98 /* internal */
99 struct list_head list;
100 struct kobject kobj;
Josh Poimboeuf0dade9f2017-02-13 19:42:35 -0600101 bool enabled;
Seth Jenningsb700e7f2014-12-16 11:58:19 -0600102};
103
Jiri Slaby8cdd0432015-05-19 12:01:19 +0200104#define klp_for_each_object(patch, obj) \
Miroslav Benesf09d9082016-04-28 16:34:08 +0200105 for (obj = patch->objs; obj->funcs || obj->name; obj++)
Jiri Slaby8cdd0432015-05-19 12:01:19 +0200106
107#define klp_for_each_func(obj, func) \
Miroslav Benesf09d9082016-04-28 16:34:08 +0200108 for (func = obj->funcs; \
109 func->old_name || func->new_func || func->old_sympos; \
110 func++)
Jiri Slaby8cdd0432015-05-19 12:01:19 +0200111
Miroslav Benes4421f8f2015-02-18 15:21:07 +0100112int klp_register_patch(struct klp_patch *);
113int klp_unregister_patch(struct klp_patch *);
114int klp_enable_patch(struct klp_patch *);
115int klp_disable_patch(struct klp_patch *);
Seth Jenningsb700e7f2014-12-16 11:58:19 -0600116
Jessica Yu255e7322016-08-17 20:58:28 -0400117void arch_klp_init_object_loaded(struct klp_patch *patch,
118 struct klp_object *obj);
119
Jessica Yu7e545d62016-03-16 20:55:39 -0400120/* Called from the module loader during module coming/going states */
121int klp_module_coming(struct module *mod);
122void klp_module_going(struct module *mod);
123
Josh Poimboeuf46c5a012017-02-13 19:42:30 -0600124void klp_update_patch_state(struct task_struct *task);
125
Jessica Yu7e545d62016-03-16 20:55:39 -0400126#else /* !CONFIG_LIVEPATCH */
127
128static inline int klp_module_coming(struct module *mod) { return 0; }
Josh Poimboeuf46c5a012017-02-13 19:42:30 -0600129static inline void klp_module_going(struct module *mod) {}
130static inline void klp_update_patch_state(struct task_struct *task) {}
Jessica Yu7e545d62016-03-16 20:55:39 -0400131
132#endif /* CONFIG_LIVEPATCH */
133
Seth Jenningsb700e7f2014-12-16 11:58:19 -0600134#endif /* _LINUX_LIVEPATCH_H_ */