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_RESTART,
  29         KMSG_DUMP_HALT,
  30         KMSG_DUMP_POWEROFF,
  31 };
  32
  33 /**
  34  * struct kmsg_dumper - kernel crash message dumper structure
  35  * @list:       Entry in the dumper list (private)
  36  * @dump:       Call into dumping code which will retrieve the data with
  37  *              through the record iterator
  38  * @max_reason: filter for highest reason number that should be dumped
  39  * @registered: Flag that specifies if this is already registered
  40  */
  41 struct kmsg_dumper {
  42         struct list_head list;
  43         void (*dump)(struct kmsg_dumper *dumper, enum kmsg_dump_reason reason);
  44         enum kmsg_dump_reason max_reason;
  45         bool active;
  46         bool registered;
  47
  48         /* private state of the kmsg iterator */
  49         u32 cur_idx;
  50         u32 next_idx;
  51         u64 cur_seq;
  52         u64 next_seq;
  53 };
  54
  55 #ifdef CONFIG_PRINTK
  56 void kmsg_dump(enum kmsg_dump_reason reason);
  57
  58 bool kmsg_dump_get_line_nolock(struct kmsg_dumper *dumper, bool syslog,
  59                                char *line, size_t size, size_t *len);
  60
  61 bool kmsg_dump_get_line(struct kmsg_dumper *dumper, bool syslog,
  62                         char *line, size_t size, size_t *len);
  63
  64 bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog,
  65                           char *buf, size_t size, size_t *len);
  66
  67 void kmsg_dump_rewind_nolock(struct kmsg_dumper *dumper);
  68
  69 void kmsg_dump_rewind(struct kmsg_dumper *dumper);
  70
  71 int kmsg_dump_register(struct kmsg_dumper *dumper);
  72
  73 int kmsg_dump_unregister(struct kmsg_dumper *dumper);
  74 #else
  75 static inline void kmsg_dump(enum kmsg_dump_reason reason)
  76 {
  77 }
  78
  79 static inline bool kmsg_dump_get_line_nolock(struct kmsg_dumper *dumper,
  80                                              bool syslog, const char *line,
  81                                              size_t size, size_t *len)
  82 {
  83         return false;
  84 }
  85
  86 static inline bool kmsg_dump_get_line(struct kmsg_dumper *dumper, bool syslog,
  87                                 const char *line, size_t size, size_t *len)
  88 {
  89         return false;
  90 }
  91
  92 static inline bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog,
  93                                         char *buf, size_t size, size_t *len)
  94 {
  95         return false;
  96 }
  97
  98 static inline void kmsg_dump_rewind_nolock(struct kmsg_dumper *dumper)
  99 {
 100 }
 101
 102 static inline void kmsg_dump_rewind(struct kmsg_dumper *dumper)
 103 {
 104 }
 105
 106 static inline int kmsg_dump_register(struct kmsg_dumper *dumper)
 107 {
 108         return -EINVAL;
 109 }
 110
 111 static inline int kmsg_dump_unregister(struct kmsg_dumper *dumper)
 112 {
 113         return -EINVAL;
 114 }
 115 #endif
 116
 117 #endif /* _LINUX_KMSG_DUMP_H */