kmsg_dump.h

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/*
 * linux/include/kmsg_dump.h
 *
 * Copyright (C) 2009 Net Insight AB
 *
 * Author: Simon Kagstrom <[email protected]>
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file COPYING in the main directory of this archive
 * for more details.
 */
#ifndef _LINUX_KMSG_DUMP_H
#define _LINUX_KMSG_DUMP_H

#include <linux/errno.h>
#include <linux/list.h>

/*
 * Keep this list arranged in rough order of priority. Anything listed after
 * KMSG_DUMP_OOPS will not be logged by default unless printk.always_kmsg_dump
 * is passed to the kernel.
 */
enum kmsg_dump_reason {
    KMSG_DUMP_UNDEF,
    KMSG_DUMP_PANIC,
    KMSG_DUMP_OOPS,
    KMSG_DUMP_EMERG,
    KMSG_DUMP_RESTART,
    KMSG_DUMP_HALT,
    KMSG_DUMP_POWEROFF,
};

struct kmsg_dumper {
    struct list_head list;
    void (*dump)(struct kmsg_dumper *dumper, enum kmsg_dump_reason reason);
    enum kmsg_dump_reason max_reason;
    bool active;
    bool registered;

    /* private state of the kmsg iterator */
    u32 cur_idx;
    u32 next_idx;
    u64 cur_seq;
    u64 next_seq;
};

#ifdef CONFIG_PRINTK
void kmsg_dump(enum kmsg_dump_reason reason);

bool kmsg_dump_get_line_nolock(struct kmsg_dumper *dumper, bool syslog,
                   char *line, size_t size, size_t *len);

bool kmsg_dump_get_line(struct kmsg_dumper *dumper, bool syslog,
            char *line, size_t size, size_t *len);

bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog,
              char *buf, size_t size, size_t *len);

void kmsg_dump_rewind_nolock(struct kmsg_dumper *dumper);

void kmsg_dump_rewind(struct kmsg_dumper *dumper);

int kmsg_dump_register(struct kmsg_dumper *dumper);

int kmsg_dump_unregister(struct kmsg_dumper *dumper);
#else
static inline void kmsg_dump(enum kmsg_dump_reason reason)
{
}

static inline bool kmsg_dump_get_line_nolock(struct kmsg_dumper *dumper,
                         bool syslog, const char *line,
                         size_t size, size_t *len)
{
    return false;
}

static inline bool kmsg_dump_get_line(struct kmsg_dumper *dumper, bool syslog,
                const char *line, size_t size, size_t *len)
{
    return false;
}

static inline bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog,
                    char *buf, size_t size, size_t *len)
{
    return false;
}

static inline void kmsg_dump_rewind_nolock(struct kmsg_dumper *dumper)
{
}

static inline void kmsg_dump_rewind(struct kmsg_dumper *dumper)
{
}

static inline int kmsg_dump_register(struct kmsg_dumper *dumper)
{
    return -EINVAL;
}

static inline int kmsg_dump_unregister(struct kmsg_dumper *dumper)
{
    return -EINVAL;
}
#endif

#endif /* _LINUX_KMSG_DUMP_H */