1 files changed, 41 insertions, 0 deletions

diff --git a/security/tomoyo/util.c b/security/tomoyo/util.c
index daf7a45f70f1..7ff54c95e1f2 100644
--- a/security/tomoyo/util.c
+++ b/security/tomoyo/util.c
@@ -47,6 +47,47 @@ const u8 tomoyo_index2category[TOMOYO_MAX_MAC_INDEX] = {
 };
 
 /**
+ * tomoyo_convert_time - Convert time_t to YYYY/MM/DD hh/mm/ss.
+ *
+ * @time:  Seconds since 1970/01/01 00:00:00.
+ * @stamp: Pointer to "struct tomoyo_time".
+ *
+ * Returns nothing.
+ *
+ * This function does not handle Y2038 problem.
+ */
+void tomoyo_convert_time(time_t time, struct tomoyo_time *stamp)
+{
+        static const u16 tomoyo_eom[2][12] = {
+                { 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 },
+                { 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 }
+        };
+        u16 y;
+        u8 m;
+        bool r;
+        stamp->sec = time % 60;
+        time /= 60;
+        stamp->min = time % 60;
+        time /= 60;
+        stamp->hour = time % 24;
+        time /= 24;
+        for (y = 1970; ; y++) {
+                const unsigned short days = (y & 3) ? 365 : 366;
+                if (time < days)
+                        break;
+                time -= days;
+        }
+        r = (y & 3) == 0;
+        for (m = 0; m < 11 && time >= tomoyo_eom[r][m]; m++)
+                ;
+        if (m)
+                time -= tomoyo_eom[r][m - 1];
+        stamp->year = y;
+        stamp->month = ++m;
+        stamp->day = ++time;
+}
+
+/**
  * tomoyo_permstr - Find permission keywords.
  *
  * @string: String representation for permissions in foo/bar/buz format.