内核中得到当前时间

在内核中得到当前时间，从vlogger中提取出来的
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/version.h>
#include <linux/module.h>
#include <linux/time.h>
#include <asm/uaccess.h>

MODULE_LICENSE("GPL");

/* Macros used to get local time */

#define SECS_PER_HOUR (60 * 60)
#define SECS_PER_DAY (SECS_PER_HOUR * 24)
#define isleap(year) \
        ((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0))
#define DIV(a, b) ((a) / (b) - ((a) % (b) < 0))
#define LEAPS_THRU_END_OF(y) (DIV (y, 4) - DIV (y, 100) + DIV (y, 400))

struct vtm
{
        int tm_sec;
        int tm_min;
        int tm_hour;
        int tm_mday;
        int tm_mon;
        int tm_year;
};

int timezone;

int epoch2time(const time_t * t, long int offset, struct vtm *tp)
{
        static const unsigned short int mon_yday[2][13] = {
                /* Normal years. */
                {0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365},
                /* Leap years. */
                {0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366}
        };

        long int days, rem, y;
        const unsigned short int *ip;

        days = *t / SECS_PER_DAY;
        rem = *t % SECS_PER_DAY;
        rem += offset;
        while (rem < 0) {
                rem += SECS_PER_DAY;
                --days;
        }
        while (rem >= SECS_PER_DAY) {
                rem -= SECS_PER_DAY;
                ++days;
        }
        tp->tm_hour = rem / SECS_PER_HOUR;
        rem %= SECS_PER_HOUR;
        tp->tm_min = rem / 60;
        tp->tm_sec = rem % 60;
        y = 1970;

        while (days < 0 || days >= (isleap(y) ? 366 : 365)) {
                long int yg = y + days / 365 - (days % 365 < 0);
                days -= ((yg - y) * 365 + LEAPS_THRU_END_OF(yg - 1)
                    - LEAPS_THRU_END_OF(y - 1));
                y = yg;
        }
        tp->tm_year = y - 1900;
        if (tp->tm_year != y - 1900)
                return 0;
        ip = mon_yday[isleap(y)];
        for (y = 11; days < (long int) ip[y]; --y)
                continue;
        days -= ip[y];
        tp->tm_mon = y;
        tp->tm_mday = days + 1;
        return 1;
}

/*
* Get current date & time
*/

void get_time(char *date_time)
{
        struct timeval tv;
        time_t t;
        struct vtm tm;

        do_gettimeofday(&tv);
        t = (time_t) tv.tv_sec;

        epoch2time(&t, timezone, &tm);

        sprintf(date_time, "%.2d/%.2d/%d-%.2d:%.2d:%.2d", tm.tm_mday,
            tm.tm_mon + 1, tm.tm_year + 1900, tm.tm_hour, tm.tm_min,
            tm.tm_sec);
}

int time_test_init(void)
{
        char data_time[24];

        get_time(data_time);

        printk("%s\n",data_time);

        return 0;
}

void time_test_exit(void)
{

}

module_init(time_test_init);
module_exit(time_test_exit);