timex: change syscalls to use struct __kernel_timex

struct timex is not y2038 safe.
Switch all the syscall apis to use y2038 safe __kernel_timex.

Note that sys_adjtimex() does not have a y2038 safe solution.  C libraries
can implement it by calling clock_adjtime(CLOCK_REALTIME, ...).
Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

include/linux/syscalls.h

@@ -54,7 +54,7 @@ struct __sysctl_args;
 struct sysinfo;
 struct timespec;
 struct timeval;
-struct timex;
+struct __kernel_timex;
 struct timezone;
 struct tms;
 struct utimbuf;
@@ -695,7 +695,7 @@ asmlinkage long sys_gettimeofday(struct timeval __user *tv,
 				struct timezone __user *tz);
 asmlinkage long sys_settimeofday(struct timeval __user *tv,
 				struct timezone __user *tz);
-asmlinkage long sys_adjtimex(struct timex __user *txc_p);
+asmlinkage long sys_adjtimex(struct __kernel_timex __user *txc_p);
 
 /* kernel/timer.c */
 asmlinkage long sys_getpid(void);
@@ -870,7 +870,7 @@ asmlinkage long sys_open_by_handle_at(int mountdirfd,
 				      struct file_handle __user *handle,
 				      int flags);
 asmlinkage long sys_clock_adjtime(clockid_t which_clock,
-				struct timex __user *tx);
+				struct __kernel_timex __user *tx);
 asmlinkage long sys_syncfs(int fd);
 asmlinkage long sys_setns(int fd, int nstype);
 asmlinkage long sys_sendmmsg(int fd, struct mmsghdr __user *msg,

kernel/time/posix-timers.c

@@ -1060,7 +1060,7 @@ int do_clock_adjtime(const clockid_t which_clock, struct __kernel_timex * ktx)
 }
 
 SYSCALL_DEFINE2(clock_adjtime, const clockid_t, which_clock,
-		struct timex __user *, utx)
+		struct __kernel_timex __user *, utx)
 {
 	struct __kernel_timex ktx;
 	int err;

kernel/time/time.c

@@ -263,7 +263,8 @@ COMPAT_SYSCALL_DEFINE2(settimeofday, struct old_timeval32 __user *, tv,
 }
 #endif
 
-SYSCALL_DEFINE1(adjtimex, struct timex __user *, txc_p)
+#if !defined(CONFIG_64BIT_TIME) || defined(CONFIG_64BIT)
+SYSCALL_DEFINE1(adjtimex, struct __kernel_timex __user *, txc_p)
 {
 	struct __kernel_timex txc;		/* Local copy of parameter */
 	int ret;
@@ -277,6 +278,7 @@ SYSCALL_DEFINE1(adjtimex, struct timex __user *, txc_p)
 	ret = do_adjtimex(&txc);
 	return copy_to_user(txc_p, &txc, sizeof(struct __kernel_timex)) ? -EFAULT : ret;
 }
+#endif
 
 #ifdef CONFIG_COMPAT_32BIT_TIME
 int get_old_timex32(struct __kernel_timex *txc, const struct old_timex32 __user *utp)