1 /* SPDX-License-Identifier: GPL-2.0 */
2
3 /*
4 * Copyright (c) 2025, Google LLC.
5 * Pasha Tatashin <pasha.tatashin@soleen.com>
6 */
7
8 #ifndef _LINUX_LUO_INTERNAL_H
9 #define _LINUX_LUO_INTERNAL_H
10
11 #include <linux/liveupdate.h>
12 #include <linux/uaccess.h>
13
14 struct luo_ucmd {
15 void __user *ubuffer;
16 u32 user_size;
17 void *cmd;
18 };
19
luo_ucmd_respond(struct luo_ucmd * ucmd,size_t kernel_cmd_size)20 static inline int luo_ucmd_respond(struct luo_ucmd *ucmd,
21 size_t kernel_cmd_size)
22 {
23 /*
24 * Copy the minimum of what the user provided and what we actually
25 * have.
26 */
27 if (copy_to_user(ucmd->ubuffer, ucmd->cmd,
28 min_t(size_t, ucmd->user_size, kernel_cmd_size))) {
29 return -EFAULT;
30 }
31 return 0;
32 }
33
34 /*
35 * Handles a deserialization failure: devices and memory is in unpredictable
36 * state.
37 *
38 * Continuing the boot process after a failure is dangerous because it could
39 * lead to leaks of private data.
40 */
41 #define luo_restore_fail(__fmt, ...) panic(__fmt, ##__VA_ARGS__)
42
43 /**
44 * struct luo_file_set - A set of files that belong to the same sessions.
45 * @files_list: An ordered list of files associated with this session, it is
46 * ordered by preservation time.
47 * @files: The physically contiguous memory block that holds the serialized
48 * state of files.
49 * @count: A counter tracking the number of files currently stored in the
50 * @files_list for this session.
51 */
52 struct luo_file_set {
53 struct list_head files_list;
54 struct luo_file_ser *files;
55 long count;
56 };
57
58 /**
59 * struct luo_session - Represents an active or incoming Live Update session.
60 * @name: A unique name for this session, used for identification and
61 * retrieval.
62 * @ser: Pointer to the serialized data for this session.
63 * @list: A list_head member used to link this session into a global list
64 * of either outgoing (to be preserved) or incoming (restored from
65 * previous kernel) sessions.
66 * @retrieved: A boolean flag indicating whether this session has been
67 * retrieved by a consumer in the new kernel.
68 * @file_set: A set of files that belong to this session.
69 * @mutex: protects fields in the luo_session.
70 */
71 struct luo_session {
72 char name[LIVEUPDATE_SESSION_NAME_LENGTH];
73 struct luo_session_ser *ser;
74 struct list_head list;
75 bool retrieved;
76 struct luo_file_set file_set;
77 struct mutex mutex;
78 };
79
80 int luo_session_create(const char *name, struct file **filep);
81 int luo_session_retrieve(const char *name, struct file **filep);
82 int __init luo_session_setup_outgoing(void *fdt);
83 int __init luo_session_setup_incoming(void *fdt);
84 int luo_session_serialize(void);
85 int luo_session_deserialize(void);
86 bool luo_session_quiesce(void);
87 void luo_session_resume(void);
88
89 int luo_preserve_file(struct luo_file_set *file_set, u64 token, int fd);
90 void luo_file_unpreserve_files(struct luo_file_set *file_set);
91 int luo_file_freeze(struct luo_file_set *file_set,
92 struct luo_file_set_ser *file_set_ser);
93 void luo_file_unfreeze(struct luo_file_set *file_set,
94 struct luo_file_set_ser *file_set_ser);
95 int luo_retrieve_file(struct luo_file_set *file_set, u64 token,
96 struct file **filep);
97 int luo_file_finish(struct luo_file_set *file_set);
98 int luo_file_deserialize(struct luo_file_set *file_set,
99 struct luo_file_set_ser *file_set_ser);
100 void luo_file_set_init(struct luo_file_set *file_set);
101 void luo_file_set_destroy(struct luo_file_set *file_set);
102
103 int luo_flb_file_preserve(struct liveupdate_file_handler *fh);
104 void luo_flb_file_unpreserve(struct liveupdate_file_handler *fh);
105 void luo_flb_file_finish(struct liveupdate_file_handler *fh);
106 int __init luo_flb_setup_outgoing(void *fdt);
107 int __init luo_flb_setup_incoming(void *fdt);
108 void luo_flb_serialize(void);
109
110 #ifdef CONFIG_LIVEUPDATE_TEST
111 void liveupdate_test_register(struct liveupdate_file_handler *fh);
112 void liveupdate_test_unregister(struct liveupdate_file_handler *fh);
113 #else
liveupdate_test_register(struct liveupdate_file_handler * fh)114 static inline void liveupdate_test_register(struct liveupdate_file_handler *fh) { }
liveupdate_test_unregister(struct liveupdate_file_handler * fh)115 static inline void liveupdate_test_unregister(struct liveupdate_file_handler *fh) { }
116 #endif
117
118 #endif /* _LINUX_LUO_INTERNAL_H */
119