kmsg_dump.h

  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 */