include/linux/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  */
  23 enum 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  */
  37 struct 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
  48 struct 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  */
  61 struct 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
  69 void kmsg_dump_desc(enum kmsg_dump_reason reason, const char *desc);
  70
  71 bool kmsg_dump_get_line(struct kmsg_dump_iter *iter, bool syslog,
  72                         char *line, size_t size, size_t *len);
  73
  74 bool kmsg_dump_get_buffer(struct kmsg_dump_iter *iter, bool syslog,
  75                           char *buf, size_t size, size_t *len_out);
  76
  77 void kmsg_dump_rewind(struct kmsg_dump_iter *iter);
  78
  79 int kmsg_dump_register(struct kmsg_dumper *dumper);
  80
  81 int kmsg_dump_unregister(struct kmsg_dumper *dumper);
  82
  83 const char *kmsg_dump_reason_str(enum kmsg_dump_reason reason);
  84 #else
  85 static inline void kmsg_dump_desc(enum kmsg_dump_reason reason, const char *desc)
  86 {
  87 }
  88
  89 static 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
  95 static 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
 101 static inline void kmsg_dump_rewind(struct kmsg_dump_iter *iter)
 102 {
 103 }
 104
 105 static inline int kmsg_dump_register(struct kmsg_dumper *dumper)
 106 {
 107         return -EINVAL;
 108 }
 109
 110 static inline int kmsg_dump_unregister(struct kmsg_dumper *dumper)
 111 {
 112         return -EINVAL;
 113 }
 114
 115 static inline const char *kmsg_dump_reason_str(enum kmsg_dump_reason reason)
 116 {
 117         return "Disabled";
 118 }
 119 #endif
 120
 121 static inline void kmsg_dump(enum kmsg_dump_reason reason)
 122 {
 123         kmsg_dump_desc(reason, NULL);
 124 }
 125
 126 #endif /* _LINUX_KMSG_DUMP_H */