lib/, src/: Call gmtime_r(3) instead of gmtime(3)

It's trivial to do the change, and it removes a CodeQL warning.
We don't need to be reentrant, but it doesn't hurt either.

Signed-off-by: Alejandro Colomar <alx@kernel.org>

2 files changed, 10 insertions, 11 deletions

diff --git a/lib/time/day_to_str.h b/lib/time/day_to_str.h
index 6aa855ac..96cec6e1 100644
--- a/lib/time/day_to_str.h
+++ b/lib/time/day_to_str.h
@@ -25,8 +25,8 @@ inline void day_to_str(size_t size, char buf[size], long day);
 inline void
 day_to_str(size_t size, char buf[size], long day)
 {
-	time_t           date;
-	const struct tm  *tm;
+	time_t     date;
+	struct tm  tm;
 
 	if (day < 0) {
 		strtcpy(buf, "never", size);
@@ -38,13 +38,12 @@ day_to_str(size_t size, char buf[size], long day)
 		return;
 	}
 
-	tm = gmtime(&date);
-	if (tm == NULL) {
+	if (gmtime_r(&date, &tm) == NULL) {
 		strtcpy(buf, "future", size);
 		return;
 	}
 
-	if (strftime(buf, size, "%Y-%m-%d", tm) == 0)
+	if (strftime(buf, size, "%Y-%m-%d", &tm) == 0)
 		strtcpy(buf, "future", size);
 }
 
diff --git a/src/chage.c b/src/chage.c
index 88e06cd3..ca61cffd 100644
--- a/src/chage.c
+++ b/src/chage.c
@@ -237,7 +237,7 @@ print_day_as_date(long day)
 {
 	char       buf[80];
 	time_t     date;
-	struct tm  *tp;
+	struct tm  tm;
 
 	if (day < 0) {
 		puts(_("never"));
@@ -248,13 +248,13 @@ print_day_as_date(long day)
 		return;
 	}
 
-	tp = gmtime (&date);
-	if (NULL == tp) {
+	if (gmtime_r(&date, &tm) == NULL) {
 		(void) printf ("time_t: %lu\n", (unsigned long)date);
-	} else {
-		(void) strftime (buf, sizeof buf, iflg ? "%Y-%m-%d" : "%b %d, %Y", tp);
-		(void) puts (buf);
+		return;
 	}
+
+	(void) strftime (buf, sizeof buf, iflg ? "%Y-%m-%d" : "%b %d, %Y", &tm);
+	(void) puts (buf);
 }