Merge tag 'y2038-cleanups-5.5' of git://git.kernel.org:/pub/scm/linux/kernel/git/arnd/playground

Pull y2038 cleanups from Arnd Bergmann:
 "y2038 syscall implementation cleanups

  This is a series of cleanups for the y2038 work, mostly intended for
  namespace cleaning: the kernel defines the traditional time_t, timeval
  and timespec types that often lead to y2038-unsafe code. Even though
  the unsafe usage is mostly gone from the kernel, having the types and
  associated functions around means that we can still grow new users,
  and that we may be missing conversions to safe types that actually
  matter.

  There are still a number of driver specific patches needed to get the
  last users of these types removed, those have been submitted to the
  respective maintainers"

Link: https://lore.kernel.org/lkml/20191108210236.1296047-1-arnd@arndb.de/

* tag 'y2038-cleanups-5.5' of git://git.kernel.org:/pub/scm/linux/kernel/git/arnd/playground: (26 commits)
  y2038: alarm: fix half-second cut-off
  y2038: ipc: fix x32 ABI breakage
  y2038: fix typo in powerpc vdso "LOPART"
  y2038: allow disabling time32 system calls
  y2038: itimer: change implementation to timespec64
  y2038: move itimer reset into itimer.c
  y2038: use compat_{get,set}_itimer on alpha
  y2038: itimer: compat handling to itimer.c
  y2038: time: avoid timespec usage in settimeofday()
  y2038: timerfd: Use timespec64 internally
  y2038: elfcore: Use __kernel_old_timeval for process times
  y2038: make ns_to_compat_timeval use __kernel_old_timeval
  y2038: socket: use __kernel_old_timespec instead of timespec
  y2038: socket: remove timespec reference in timestamping
  y2038: syscalls: change remaining timeval to __kernel_old_timeval
  y2038: rusage: use __kernel_old_timeval
  y2038: uapi: change __kernel_time_t to __kernel_old_time_t
  y2038: stat: avoid 'time_t' in 'struct stat'
  y2038: ipc: remove __kernel_time_t reference from headers
  y2038: vdso: powerpc: avoid timespec references
  ...

3 files changed, 147 insertions, 76 deletions

diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
index 65605530ee34..9e20873148c6 100644
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -1940,7 +1940,7 @@ out:
 	return ret;
 }
 
-#if !defined(CONFIG_64BIT_TIME) || defined(CONFIG_64BIT)
+#ifdef CONFIG_64BIT
 
 SYSCALL_DEFINE2(nanosleep, struct __kernel_timespec __user *, rqtp,
 		struct __kernel_timespec __user *, rmtp)
diff --git a/kernel/time/itimer.c b/kernel/time/itimer.c
index 77f1e5635cc1..9e59c9ea92aa 100644
--- a/kernel/time/itimer.c
+++ b/kernel/time/itimer.c
@@ -26,7 +26,7 @@
  * Returns the delta between the expiry time and now, which can be
  * less than zero or 1usec for an pending expired timer
  */
-static struct timeval itimer_get_remtime(struct hrtimer *timer)
+static struct timespec64 itimer_get_remtime(struct hrtimer *timer)
 {
 	ktime_t rem = __hrtimer_get_remaining(timer, true);
 
@@ -41,11 +41,11 @@ static struct timeval itimer_get_remtime(struct hrtimer *timer)
 	} else
 		rem = 0;
 
-	return ktime_to_timeval(rem);
+	return ktime_to_timespec64(rem);
 }
 
 static void get_cpu_itimer(struct task_struct *tsk, unsigned int clock_id,
-			   struct itimerval *const value)
+			   struct itimerspec64 *const value)
 {
 	u64 val, interval;
 	struct cpu_itimer *it = &tsk->signal->it[clock_id];
@@ -69,11 +69,11 @@ static void get_cpu_itimer(struct task_struct *tsk, unsigned int clock_id,
 
 	spin_unlock_irq(&tsk->sighand->siglock);
 
-	value->it_value = ns_to_timeval(val);
-	value->it_interval = ns_to_timeval(interval);
+	value->it_value = ns_to_timespec64(val);
+	value->it_interval = ns_to_timespec64(interval);
 }
 
-int do_getitimer(int which, struct itimerval *value)
+static int do_getitimer(int which, struct itimerspec64 *value)
 {
 	struct task_struct *tsk = current;
 
@@ -82,7 +82,7 @@ int do_getitimer(int which, struct itimerval *value)
 		spin_lock_irq(&tsk->sighand->siglock);
 		value->it_value = itimer_get_remtime(&tsk->signal->real_timer);
 		value->it_interval =
-			ktime_to_timeval(tsk->signal->it_real_incr);
+			ktime_to_timespec64(tsk->signal->it_real_incr);
 		spin_unlock_irq(&tsk->sighand->siglock);
 		break;
 	case ITIMER_VIRTUAL:
@@ -97,34 +97,59 @@ int do_getitimer(int which, struct itimerval *value)
 	return 0;
 }
 
+static int put_itimerval(struct itimerval __user *o,
+			 const struct itimerspec64 *i)
+{
+	struct itimerval v;
+
+	v.it_interval.tv_sec = i->it_interval.tv_sec;
+	v.it_interval.tv_usec = i->it_interval.tv_nsec / NSEC_PER_USEC;
+	v.it_value.tv_sec = i->it_value.tv_sec;
+	v.it_value.tv_usec = i->it_value.tv_nsec / NSEC_PER_USEC;
+	return copy_to_user(o, &v, sizeof(struct itimerval)) ? -EFAULT : 0;
+}
+
+
 SYSCALL_DEFINE2(getitimer, int, which, struct itimerval __user *, value)
 {
-	int error = -EFAULT;
-	struct itimerval get_buffer;
+	struct itimerspec64 get_buffer;
+	int error = do_getitimer(which, &get_buffer);
 
-	if (value) {
-		error = do_getitimer(which, &get_buffer);
-		if (!error &&
-		    copy_to_user(value, &get_buffer, sizeof(get_buffer)))
-			error = -EFAULT;
-	}
+	if (!error && put_itimerval(value, &get_buffer))
+		error = -EFAULT;
 	return error;
 }
 
-#ifdef CONFIG_COMPAT
+#if defined(CONFIG_COMPAT) || defined(CONFIG_ALPHA)
+struct old_itimerval32 {
+	struct old_timeval32	it_interval;
+	struct old_timeval32	it_value;
+};
+
+static int put_old_itimerval32(struct old_itimerval32 __user *o,
+			       const struct itimerspec64 *i)
+{
+	struct old_itimerval32 v32;
+
+	v32.it_interval.tv_sec = i->it_interval.tv_sec;
+	v32.it_interval.tv_usec = i->it_interval.tv_nsec / NSEC_PER_USEC;
+	v32.it_value.tv_sec = i->it_value.tv_sec;
+	v32.it_value.tv_usec = i->it_value.tv_nsec / NSEC_PER_USEC;
+	return copy_to_user(o, &v32, sizeof(struct old_itimerval32)) ? -EFAULT : 0;
+}
+
 COMPAT_SYSCALL_DEFINE2(getitimer, int, which,
-		       struct compat_itimerval __user *, it)
+		       struct old_itimerval32 __user *, value)
 {
-	struct itimerval kit;
-	int error = do_getitimer(which, &kit);
+	struct itimerspec64 get_buffer;
+	int error = do_getitimer(which, &get_buffer);
 
-	if (!error && put_compat_itimerval(it, &kit))
+	if (!error && put_old_itimerval32(value, &get_buffer))
 		error = -EFAULT;
 	return error;
 }
 #endif
 
-
 /*
  * The timer is automagically restarted, when interval != 0
  */
@@ -141,8 +166,8 @@ enum hrtimer_restart it_real_fn(struct hrtimer *timer)
 }
 
 static void set_cpu_itimer(struct task_struct *tsk, unsigned int clock_id,
-			   const struct itimerval *const value,
-			   struct itimerval *const ovalue)
+			   const struct itimerspec64 *const value,
+			   struct itimerspec64 *const ovalue)
 {
 	u64 oval, nval, ointerval, ninterval;
 	struct cpu_itimer *it = &tsk->signal->it[clock_id];
@@ -151,8 +176,8 @@ static void set_cpu_itimer(struct task_struct *tsk, unsigned int clock_id,
 	 * Use the to_ktime conversion because that clamps the maximum
 	 * value to KTIME_MAX and avoid multiplication overflows.
 	 */
-	nval = ktime_to_ns(timeval_to_ktime(value->it_value));
-	ninterval = ktime_to_ns(timeval_to_ktime(value->it_interval));
+	nval = timespec64_to_ns(&value->it_value);
+	ninterval = timespec64_to_ns(&value->it_interval);
 
 	spin_lock_irq(&tsk->sighand->siglock);
 
@@ -171,8 +196,8 @@ static void set_cpu_itimer(struct task_struct *tsk, unsigned int clock_id,
 	spin_unlock_irq(&tsk->sighand->siglock);
 
 	if (ovalue) {
-		ovalue->it_value = ns_to_timeval(oval);
-		ovalue->it_interval = ns_to_timeval(ointerval);
+		ovalue->it_value = ns_to_timespec64(oval);
+		ovalue->it_interval = ns_to_timespec64(ointerval);
 	}
 }
 
@@ -182,19 +207,13 @@ static void set_cpu_itimer(struct task_struct *tsk, unsigned int clock_id,
 #define timeval_valid(t) \
 	(((t)->tv_sec >= 0) && (((unsigned long) (t)->tv_usec) < USEC_PER_SEC))
 
-int do_setitimer(int which, struct itimerval *value, struct itimerval *ovalue)
+static int do_setitimer(int which, struct itimerspec64 *value,
+			struct itimerspec64 *ovalue)
 {
 	struct task_struct *tsk = current;
 	struct hrtimer *timer;
 	ktime_t expires;
 
-	/*
-	 * Validate the timevals in value.
-	 */
-	if (!timeval_valid(&value->it_value) ||
-	    !timeval_valid(&value->it_interval))
-		return -EINVAL;
-
 	switch (which) {
 	case ITIMER_REAL:
 again:
@@ -203,7 +222,7 @@ again:
 		if (ovalue) {
 			ovalue->it_value = itimer_get_remtime(timer);
 			ovalue->it_interval
-				= ktime_to_timeval(tsk->signal->it_real_incr);
+				= ktime_to_timespec64(tsk->signal->it_real_incr);
 		}
 		/* We are sharing ->siglock with it_real_fn() */
 		if (hrtimer_try_to_cancel(timer) < 0) {
@@ -211,10 +230,10 @@ again:
 			hrtimer_cancel_wait_running(timer);
 			goto again;
 		}
-		expires = timeval_to_ktime(value->it_value);
+		expires = timespec64_to_ktime(value->it_value);
 		if (expires != 0) {
 			tsk->signal->it_real_incr =
-				timeval_to_ktime(value->it_interval);
+				timespec64_to_ktime(value->it_interval);
 			hrtimer_start(timer, expires, HRTIMER_MODE_REL);
 		} else
 			tsk->signal->it_real_incr = 0;
@@ -234,6 +253,17 @@ again:
 	return 0;
 }
 
+#ifdef CONFIG_SECURITY_SELINUX
+void clear_itimer(void)
+{
+	struct itimerspec64 v = {};
+	int i;
+
+	for (i = 0; i < 3; i++)
+		do_setitimer(i, &v, NULL);
+}
+#endif
+
 #ifdef __ARCH_WANT_SYS_ALARM
 
 /**
@@ -250,15 +280,15 @@ again:
  */
 static unsigned int alarm_setitimer(unsigned int seconds)
 {
-	struct itimerval it_new, it_old;
+	struct itimerspec64 it_new, it_old;
 
 #if BITS_PER_LONG < 64
 	if (seconds > INT_MAX)
 		seconds = INT_MAX;
 #endif
 	it_new.it_value.tv_sec = seconds;
-	it_new.it_value.tv_usec = 0;
-	it_new.it_interval.tv_sec = it_new.it_interval.tv_usec = 0;
+	it_new.it_value.tv_nsec = 0;
+	it_new.it_interval.tv_sec = it_new.it_interval.tv_nsec = 0;
 
 	do_setitimer(ITIMER_REAL, &it_new, &it_old);
 
@@ -266,8 +296,8 @@ static unsigned int alarm_setitimer(unsigned int seconds)
 	 * We can't return 0 if we have an alarm pending ...  And we'd
 	 * better return too much than too little anyway
 	 */
-	if ((!it_old.it_value.tv_sec && it_old.it_value.tv_usec) ||
-	      it_old.it_value.tv_usec >= 500000)
+	if ((!it_old.it_value.tv_sec && it_old.it_value.tv_nsec) ||
+	      it_old.it_value.tv_nsec >= (NSEC_PER_SEC / 2))
 		it_old.it_value.tv_sec++;
 
 	return it_old.it_value.tv_sec;
@@ -284,15 +314,35 @@ SYSCALL_DEFINE1(alarm, unsigned int, seconds)
 
 #endif
 
+static int get_itimerval(struct itimerspec64 *o, const struct itimerval __user *i)
+{
+	struct itimerval v;
+
+	if (copy_from_user(&v, i, sizeof(struct itimerval)))
+		return -EFAULT;
+
+	/* Validate the timevals in value. */
+	if (!timeval_valid(&v.it_value) ||
+	    !timeval_valid(&v.it_interval))
+		return -EINVAL;
+
+	o->it_interval.tv_sec = v.it_interval.tv_sec;
+	o->it_interval.tv_nsec = v.it_interval.tv_usec * NSEC_PER_USEC;
+	o->it_value.tv_sec = v.it_value.tv_sec;
+	o->it_value.tv_nsec = v.it_value.tv_usec * NSEC_PER_USEC;
+	return 0;
+}
+
 SYSCALL_DEFINE3(setitimer, int, which, struct itimerval __user *, value,
 		struct itimerval __user *, ovalue)
 {
-	struct itimerval set_buffer, get_buffer;
+	struct itimerspec64 set_buffer, get_buffer;
 	int error;
 
 	if (value) {
-		if(copy_from_user(&set_buffer, value, sizeof(set_buffer)))
-			return -EFAULT;
+		error = get_itimerval(&set_buffer, value);
+		if (error)
+			return error;
 	} else {
 		memset(&set_buffer, 0, sizeof(set_buffer));
 		printk_once(KERN_WARNING "%s calls setitimer() with new_value NULL pointer."
@@ -304,30 +354,53 @@ SYSCALL_DEFINE3(setitimer, int, which, struct itimerval __user *, value,
 	if (error || !ovalue)
 		return error;
 
-	if (copy_to_user(ovalue, &get_buffer, sizeof(get_buffer)))
+	if (put_itimerval(ovalue, &get_buffer))
+		return -EFAULT;
+	return 0;
+}
+
+#if defined(CONFIG_COMPAT) || defined(CONFIG_ALPHA)
+static int get_old_itimerval32(struct itimerspec64 *o, const struct old_itimerval32 __user *i)
+{
+	struct old_itimerval32 v32;
+
+	if (copy_from_user(&v32, i, sizeof(struct old_itimerval32)))
 		return -EFAULT;
+
+	/* Validate the timevals in value.  */
+	if (!timeval_valid(&v32.it_value) ||
+	    !timeval_valid(&v32.it_interval))
+		return -EINVAL;
+
+	o->it_interval.tv_sec = v32.it_interval.tv_sec;
+	o->it_interval.tv_nsec = v32.it_interval.tv_usec * NSEC_PER_USEC;
+	o->it_value.tv_sec = v32.it_value.tv_sec;
+	o->it_value.tv_nsec = v32.it_value.tv_usec * NSEC_PER_USEC;
 	return 0;
 }
 
-#ifdef CONFIG_COMPAT
 COMPAT_SYSCALL_DEFINE3(setitimer, int, which,
-		       struct compat_itimerval __user *, in,
-		       struct compat_itimerval __user *, out)
+		       struct old_itimerval32 __user *, value,
+		       struct old_itimerval32 __user *, ovalue)
 {
-	struct itimerval kin, kout;
+	struct itimerspec64 set_buffer, get_buffer;
 	int error;
 
-	if (in) {
-		if (get_compat_itimerval(&kin, in))
-			return -EFAULT;
+	if (value) {
+		error = get_old_itimerval32(&set_buffer, value);
+		if (error)
+			return error;
 	} else {
-		memset(&kin, 0, sizeof(kin));
+		memset(&set_buffer, 0, sizeof(set_buffer));
+		printk_once(KERN_WARNING "%s calls setitimer() with new_value NULL pointer."
+			    " Misfeature support will be removed\n",
+			    current->comm);
 	}
 
-	error = do_setitimer(which, &kin, out ? &kout : NULL);
-	if (error || !out)
+	error = do_setitimer(which, &set_buffer, ovalue ? &get_buffer : NULL);
+	if (error || !ovalue)
 		return error;
-	if (put_compat_itimerval(out, &kout))
+	if (put_old_itimerval32(ovalue, &get_buffer))
 		return -EFAULT;
 	return 0;
 }
diff --git a/kernel/time/time.c b/kernel/time/time.c
index 5c54ca632d08..58e312e7380f 100644
--- a/kernel/time/time.c
+++ b/kernel/time/time.c
@@ -59,9 +59,9 @@ EXPORT_SYMBOL(sys_tz);
  * why not move it into the appropriate arch directory (for those
  * architectures that need it).
  */
-SYSCALL_DEFINE1(time, time_t __user *, tloc)
+SYSCALL_DEFINE1(time, __kernel_old_time_t __user *, tloc)
 {
-	time_t i = (time_t)ktime_get_real_seconds();
+	__kernel_old_time_t i = (__kernel_old_time_t)ktime_get_real_seconds();
 
 	if (tloc) {
 		if (put_user(i,tloc))
@@ -78,7 +78,7 @@ SYSCALL_DEFINE1(time, time_t __user *, tloc)
  * architectures that need it).
  */
 
-SYSCALL_DEFINE1(stime, time_t __user *, tptr)
+SYSCALL_DEFINE1(stime, __kernel_old_time_t __user *, tptr)
 {
 	struct timespec64 tv;
 	int err;
@@ -137,7 +137,7 @@ SYSCALL_DEFINE1(stime32, old_time32_t __user *, tptr)
 #endif /* __ARCH_WANT_SYS_TIME32 */
 #endif
 
-SYSCALL_DEFINE2(gettimeofday, struct timeval __user *, tv,
+SYSCALL_DEFINE2(gettimeofday, struct __kernel_old_timeval __user *, tv,
 		struct timezone __user *, tz)
 {
 	if (likely(tv != NULL)) {
@@ -196,22 +196,21 @@ int do_sys_settimeofday64(const struct timespec64 *tv, const struct timezone *tz
 	return 0;
 }
 
-SYSCALL_DEFINE2(settimeofday, struct timeval __user *, tv,
+SYSCALL_DEFINE2(settimeofday, struct __kernel_old_timeval __user *, tv,
 		struct timezone __user *, tz)
 {
 	struct timespec64 new_ts;
-	struct timeval user_tv;
 	struct timezone new_tz;
 
 	if (tv) {
-		if (copy_from_user(&user_tv, tv, sizeof(*tv)))
+		if (get_user(new_ts.tv_sec, &tv->tv_sec) ||
+		    get_user(new_ts.tv_nsec, &tv->tv_usec))
 			return -EFAULT;
 
-		if (!timeval_valid(&user_tv))
+		if (new_ts.tv_nsec > USEC_PER_SEC || new_ts.tv_nsec < 0)
 			return -EINVAL;
 
-		new_ts.tv_sec = user_tv.tv_sec;
-		new_ts.tv_nsec = user_tv.tv_usec * NSEC_PER_USEC;
+		new_ts.tv_nsec *= NSEC_PER_USEC;
 	}
 	if (tz) {
 		if (copy_from_user(&new_tz, tz, sizeof(*tz)))
@@ -245,18 +244,17 @@ COMPAT_SYSCALL_DEFINE2(settimeofday, struct old_timeval32 __user *, tv,
 		       struct timezone __user *, tz)
 {
 	struct timespec64 new_ts;
-	struct timeval user_tv;
 	struct timezone new_tz;
 
 	if (tv) {
-		if (compat_get_timeval(&user_tv, tv))
+		if (get_user(new_ts.tv_sec, &tv->tv_sec) ||
+		    get_user(new_ts.tv_nsec, &tv->tv_usec))
 			return -EFAULT;
 
-		if (!timeval_valid(&user_tv))
+		if (new_ts.tv_nsec > USEC_PER_SEC || new_ts.tv_nsec < 0)
 			return -EINVAL;
 
-		new_ts.tv_sec = user_tv.tv_sec;
-		new_ts.tv_nsec = user_tv.tv_usec * NSEC_PER_USEC;
+		new_ts.tv_nsec *= NSEC_PER_USEC;
 	}
 	if (tz) {
 		if (copy_from_user(&new_tz, tz, sizeof(*tz)))
@@ -267,7 +265,7 @@ COMPAT_SYSCALL_DEFINE2(settimeofday, struct old_timeval32 __user *, tv,
 }
 #endif
 
-#if !defined(CONFIG_64BIT_TIME) || defined(CONFIG_64BIT)
+#ifdef CONFIG_64BIT
 SYSCALL_DEFINE1(adjtimex, struct __kernel_timex __user *, txc_p)
 {
 	struct __kernel_timex txc;		/* Local copy of parameter */
@@ -881,7 +879,7 @@ int get_timespec64(struct timespec64 *ts,
 	ts->tv_sec = kts.tv_sec;
 
 	/* Zero out the padding for 32 bit systems or in compat mode */
-	if (IS_ENABLED(CONFIG_64BIT_TIME) && in_compat_syscall())
+	if (in_compat_syscall())
 		kts.tv_nsec &= 0xFFFFFFFFUL;
 
 	ts->tv_nsec = kts.tv_nsec;