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 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 /* Mimics list_for_each_entry() but for private list head entries */ 44 #define luo_list_for_each_private(pos, head, member) \ 45 for (struct list_head *__iter = (head)->next; \ 46 __iter != (head) && \ 47 ({ pos = container_of(__iter, typeof(*(pos)), member); 1; }); \ 48 __iter = __iter->next) 49 50 /** 51 * struct luo_file_set - A set of files that belong to the same sessions. 52 * @files_list: An ordered list of files associated with this session, it is 53 * ordered by preservation time. 54 * @files: The physically contiguous memory block that holds the serialized 55 * state of files. 56 * @count: A counter tracking the number of files currently stored in the 57 * @files_list for this session. 58 */ 59 struct luo_file_set { 60 struct list_head files_list; 61 struct luo_file_ser *files; 62 long count; 63 }; 64 65 /** 66 * struct luo_session - Represents an active or incoming Live Update session. 67 * @name: A unique name for this session, used for identification and 68 * retrieval. 69 * @ser: Pointer to the serialized data for this session. 70 * @list: A list_head member used to link this session into a global list 71 * of either outgoing (to be preserved) or incoming (restored from 72 * previous kernel) sessions. 73 * @retrieved: A boolean flag indicating whether this session has been 74 * retrieved by a consumer in the new kernel. 75 * @file_set: A set of files that belong to this session. 76 * @mutex: protects fields in the luo_session. 77 */ 78 struct luo_session { 79 char name[LIVEUPDATE_SESSION_NAME_LENGTH]; 80 struct luo_session_ser *ser; 81 struct list_head list; 82 bool retrieved; 83 struct luo_file_set file_set; 84 struct mutex mutex; 85 }; 86 87 int luo_session_create(const char *name, struct file **filep); 88 int luo_session_retrieve(const char *name, struct file **filep); 89 int __init luo_session_setup_outgoing(void *fdt); 90 int __init luo_session_setup_incoming(void *fdt); 91 int luo_session_serialize(void); 92 int luo_session_deserialize(void); 93 bool luo_session_quiesce(void); 94 void luo_session_resume(void); 95 96 int luo_preserve_file(struct luo_file_set *file_set, u64 token, int fd); 97 void luo_file_unpreserve_files(struct luo_file_set *file_set); 98 int luo_file_freeze(struct luo_file_set *file_set, 99 struct luo_file_set_ser *file_set_ser); 100 void luo_file_unfreeze(struct luo_file_set *file_set, 101 struct luo_file_set_ser *file_set_ser); 102 int luo_retrieve_file(struct luo_file_set *file_set, u64 token, 103 struct file **filep); 104 int luo_file_finish(struct luo_file_set *file_set); 105 int luo_file_deserialize(struct luo_file_set *file_set, 106 struct luo_file_set_ser *file_set_ser); 107 void luo_file_set_init(struct luo_file_set *file_set); 108 void luo_file_set_destroy(struct luo_file_set *file_set); 109 110 #endif /* _LINUX_LUO_INTERNAL_H */ 111