1/*
2 * linux/include/kmsg_dump.h
3 *
4 * Copyright (C) 2009 Net Insight AB
5 *
6 * Author: Simon Kagstrom <simon.kagstrom@netinsight.net>
7 *
8 * This file is subject to the terms and conditions of the GNU General Public
9 * License. See the file COPYING in the main directory of this archive
10 * for more details.
11 */
12#ifndef _LINUX_KMSG_DUMP_H
13#define _LINUX_KMSG_DUMP_H
14
15#include <linux/errno.h>
16#include <linux/list.h>
17
18/*
19 * Keep this list arranged in rough order of priority. Anything listed after
20 * KMSG_DUMP_OOPS will not be logged by default unless printk.always_kmsg_dump
21 * is passed to the kernel.
22 */
23enum kmsg_dump_reason {
24 KMSG_DUMP_UNDEF,
25 KMSG_DUMP_PANIC,
26 KMSG_DUMP_OOPS,
27 KMSG_DUMP_EMERG,
28 KMSG_DUMP_SHUTDOWN,
29 KMSG_DUMP_MAX
30};
31
32/**
33 * struct kmsg_dump_iter - iterator for retrieving kernel messages
34 * @cur_seq: Points to the oldest message to dump
35 * @next_seq: Points after the newest message to dump
36 */
37struct kmsg_dump_iter {
38 u64 cur_seq;
39 u64 next_seq;
40};
41
42/**
43 * struct kmsg_dump_detail - kernel crash detail
44 * @reason: reason for the crash, see kmsg_dump_reason.
45 * @description: optional short string, to provide additional information.
46 */
47
48struct kmsg_dump_detail {
49 enum kmsg_dump_reason reason;
50 const char *description;
51};
52
53/**
54 * struct kmsg_dumper - kernel crash message dumper structure
55 * @list: Entry in the dumper list (private)
56 * @dump: Call into dumping code which will retrieve the data with
57 * through the record iterator
58 * @max_reason: filter for highest reason number that should be dumped
59 * @registered: Flag that specifies if this is already registered
60 */
61struct kmsg_dumper {
62 struct list_head list;
63 void (*dump)(struct kmsg_dumper *dumper, struct kmsg_dump_detail *detail);
64 enum kmsg_dump_reason max_reason;
65 bool registered;
66};
67
68#ifdef CONFIG_PRINTK
69void kmsg_dump_desc(enum kmsg_dump_reason reason, const char *desc);
70
71bool kmsg_dump_get_line(struct kmsg_dump_iter *iter, bool syslog,
72 char *line, size_t size, size_t *len);
73
74bool kmsg_dump_get_buffer(struct kmsg_dump_iter *iter, bool syslog,
75 char *buf, size_t size, size_t *len_out);
76
77void kmsg_dump_rewind(struct kmsg_dump_iter *iter);
78
79int kmsg_dump_register(struct kmsg_dumper *dumper);
80
81int kmsg_dump_unregister(struct kmsg_dumper *dumper);
82
83const char *kmsg_dump_reason_str(enum kmsg_dump_reason reason);
84#else
85static inline void kmsg_dump_desc(enum kmsg_dump_reason reason, const char *desc)
86{
87}
88
89static inline bool kmsg_dump_get_line(struct kmsg_dump_iter *iter, bool syslog,
90 const char *line, size_t size, size_t *len)
91{
92 return false;
93}
94
95static inline bool kmsg_dump_get_buffer(struct kmsg_dump_iter *iter, bool syslog,
96 char *buf, size_t size, size_t *len)
97{
98 return false;
99}
100
101static inline void kmsg_dump_rewind(struct kmsg_dump_iter *iter)
102{
103}
104
105static inline int kmsg_dump_register(struct kmsg_dumper *dumper)
106{
107 return -EINVAL;
108}
109
110static inline int kmsg_dump_unregister(struct kmsg_dumper *dumper)
111{
112 return -EINVAL;
113}
114
115static inline const char *kmsg_dump_reason_str(enum kmsg_dump_reason reason)
116{
117 return "Disabled";
118}
119#endif
120
121static inline void kmsg_dump(enum kmsg_dump_reason reason)
122{
123 kmsg_dump_desc(reason, NULL);
124}
125
126#endif /* _LINUX_KMSG_DUMP_H */
127