y2038: hide timeval/timespec/itimerval/itimerspec types

There are no in-kernel users remaining, but there may still be users that
include linux/time.h instead of sys/time.h from user space, so leave the
types available to user space while hiding them from kernel space.

Only the __kernel_old_* versions of these types remain now.

Link: http://lkml.kernel.org/r/20200110154232.4104492-4-arnd@arndb.de
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Deepa Dinamani <deepa.kernel@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/uapi/asm-generic/posix_types.h

@@ -87,7 +87,9 @@ typedef struct {
 typedef __kernel_long_t	__kernel_off_t;
 typedef long long	__kernel_loff_t;
 typedef __kernel_long_t	__kernel_old_time_t;
+#ifndef __KERNEL__
 typedef __kernel_long_t	__kernel_time_t;
+#endif
 typedef long long __kernel_time64_t;
 typedef __kernel_long_t	__kernel_clock_t;
 typedef int		__kernel_timer_t;

include/uapi/linux/time.h

@@ -5,6 +5,7 @@
 #include <linux/types.h>
 #include <linux/time_types.h>
 
+#ifndef __KERNEL__
 #ifndef _STRUCT_TIMESPEC
 #define _STRUCT_TIMESPEC
 struct timespec {
@@ -18,6 +19,17 @@ struct timeval {
 	__kernel_suseconds_t	tv_usec;	/* microseconds */
 };
 
+struct itimerspec {
+	struct timespec it_interval;/* timer period */
+	struct timespec it_value;	/* timer expiration */
+};
+
+struct itimerval {
+	struct timeval it_interval;/* timer interval */
+	struct timeval it_value;	/* current value */
+};
+#endif
+
 struct timezone {
 	int	tz_minuteswest;	/* minutes west of Greenwich */
 	int	tz_dsttime;	/* type of dst correction */
@@ -31,16 +43,6 @@ struct timezone {
 #define	ITIMER_VIRTUAL		1
 #define	ITIMER_PROF		2
 
-struct itimerspec {
-	struct timespec it_interval;	/* timer period */
-	struct timespec it_value;	/* timer expiration */
-};
-
-struct itimerval {
-	struct timeval it_interval;	/* timer interval */
-	struct timeval it_value;	/* current value */
-};
-
 /*
  * The IDs of the various system clocks (for POSIX.1b interval timers):
  */