lib/vsprintf: Print time64_t in human readable format

There are users which print time and date represented by content of
time64_t type in human readable format.

Instead of open coding that each time introduce %ptT[dt][r] specifier.

Few test cases for %ptT specifier has been added as well.

Link: https://lore.kernel.org/r/20200415170046.33374-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Rewieved-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>

1 files changed, 29 insertions, 2 deletions

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 7c488a1ce318..adbcca9c9cba 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -34,6 +34,7 @@
 #include <linux/dcache.h>
 #include <linux/cred.h>
 #include <linux/rtc.h>
+#include <linux/time.h>
 #include <linux/uuid.h>
 #include <linux/of.h>
 #include <net/addrconf.h>
@@ -1820,14 +1821,39 @@ char *rtc_str(char *buf, char *end, const struct rtc_time *tm,
 }
 
 static noinline_for_stack
+char *time64_str(char *buf, char *end, const time64_t time,
+		 struct printf_spec spec, const char *fmt)
+{
+	struct rtc_time rtc_time;
+	struct tm tm;
+
+	time64_to_tm(time, 0, &tm);
+
+	rtc_time.tm_sec = tm.tm_sec;
+	rtc_time.tm_min = tm.tm_min;
+	rtc_time.tm_hour = tm.tm_hour;
+	rtc_time.tm_mday = tm.tm_mday;
+	rtc_time.tm_mon = tm.tm_mon;
+	rtc_time.tm_year = tm.tm_year;
+	rtc_time.tm_wday = tm.tm_wday;
+	rtc_time.tm_yday = tm.tm_yday;
+
+	rtc_time.tm_isdst = 0;
+
+	return rtc_str(buf, end, &rtc_time, spec, fmt);
+}
+
+static noinline_for_stack
 char *time_and_date(char *buf, char *end, void *ptr, struct printf_spec spec,
 		    const char *fmt)
 {
 	switch (fmt[1]) {
 	case 'R':
 		return rtc_str(buf, end, (const struct rtc_time *)ptr, spec, fmt);
+	case 'T':
+		return time64_str(buf, end, *(const time64_t *)ptr, spec, fmt);
 	default:
-		return error_string(buf, end, "(%ptR?)", spec);
+		return error_string(buf, end, "(%pt?)", spec);
 	}
 }
 
@@ -2143,8 +2169,9 @@ char *fwnode_string(char *buf, char *end, struct fwnode_handle *fwnode,
  * - 'd[234]' For a dentry name (optionally 2-4 last components)
  * - 'D[234]' Same as 'd' but for a struct file
  * - 'g' For block_device name (gendisk + partition number)
- * - 't[R][dt][r]' For time and date as represented:
+ * - 't[RT][dt][r]' For time and date as represented by:
  *      R    struct rtc_time
+ *      T    time64_t
  * - 'C' For a clock, it prints the name (Common Clock Framework) or address
  *       (legacy clock framework) of the clock
  * - 'Cn' For a clock, it prints the name (Common Clock Framework) or address