y2038: globally rename compat_time to old_time32

Christoph Hellwig suggested a slightly different path for handling
backwards compatibility with the 32-bit time_t based system calls:

Rather than simply reusing the compat_sys_* entry points on 32-bit
architectures unchanged, we get rid of those entry points and the
compat_time types by renaming them to something that makes more sense
on 32-bit architectures (which don't have a compat mode otherwise),
and then share the entry points under the new name with the 64-bit
architectures that use them for implementing the compatibility.

The following types and interfaces are renamed here, and moved
from linux/compat_time.h to linux/time32.h:

old				new
---				---
compat_time_t			old_time32_t
struct compat_timeval		struct old_timeval32
struct compat_timespec		struct old_timespec32
struct compat_itimerspec	struct old_itimerspec32
ns_to_compat_timeval()		ns_to_old_timeval32()
get_compat_itimerspec64()	get_old_itimerspec32()
put_compat_itimerspec64()	put_old_itimerspec32()
compat_get_timespec64()		get_old_timespec32()
compat_put_timespec64()		put_old_timespec32()

As we already have aliases in place, this patch addresses only the
instances that are relevant to the system call interface in particular,
not those that occur in device drivers and other modules. Those
will get handled separately, while providing the 64-bit version
of the respective interfaces.

I'm not renaming the timex, rusage and itimerval structures, as we are
still debating what the new interface will look like, and whether we
will need a replacement at all.

This also doesn't change the names of the syscall entry points, which can
be done more easily when we actually switch over the 32-bit architectures
to use them, at that point we need to change COMPAT_SYSCALL_DEFINEx to
SYSCALL_DEFINEx with a new name, e.g. with a _time32 suffix.

Suggested-by: Christoph Hellwig <hch@infradead.org>
Link: https://lore.kernel.org/lkml/20180705222110.GA5698@infradead.org/
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

8 files changed, 65 insertions, 65 deletions

diff --git a/kernel/compat.c b/kernel/compat.c
index 8e40efc2928a..089d00d0da9c 100644
--- a/kernel/compat.c
+++ b/kernel/compat.c
@@ -93,28 +93,28 @@ int compat_put_timex(struct compat_timex __user *utp, const struct timex *txc)
 	return 0;
 }
 
-static int __compat_get_timeval(struct timeval *tv, const struct compat_timeval __user *ctv)
+static int __compat_get_timeval(struct timeval *tv, const struct old_timeval32 __user *ctv)
 {
 	return (!access_ok(VERIFY_READ, ctv, sizeof(*ctv)) ||
 			__get_user(tv->tv_sec, &ctv->tv_sec) ||
 			__get_user(tv->tv_usec, &ctv->tv_usec)) ? -EFAULT : 0;
 }
 
-static int __compat_put_timeval(const struct timeval *tv, struct compat_timeval __user *ctv)
+static int __compat_put_timeval(const struct timeval *tv, struct old_timeval32 __user *ctv)
 {
 	return (!access_ok(VERIFY_WRITE, ctv, sizeof(*ctv)) ||
 			__put_user(tv->tv_sec, &ctv->tv_sec) ||
 			__put_user(tv->tv_usec, &ctv->tv_usec)) ? -EFAULT : 0;
 }
 
-static int __compat_get_timespec(struct timespec *ts, const struct compat_timespec __user *cts)
+static int __compat_get_timespec(struct timespec *ts, const struct old_timespec32 __user *cts)
 {
 	return (!access_ok(VERIFY_READ, cts, sizeof(*cts)) ||
 			__get_user(ts->tv_sec, &cts->tv_sec) ||
 			__get_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0;
 }
 
-static int __compat_put_timespec(const struct timespec *ts, struct compat_timespec __user *cts)
+static int __compat_put_timespec(const struct timespec *ts, struct old_timespec32 __user *cts)
 {
 	return (!access_ok(VERIFY_WRITE, cts, sizeof(*cts)) ||
 			__put_user(ts->tv_sec, &cts->tv_sec) ||
diff --git a/kernel/futex_compat.c b/kernel/futex_compat.c
index 83f830acbb5f..410a77a8f6e2 100644
--- a/kernel/futex_compat.c
+++ b/kernel/futex_compat.c
@@ -173,7 +173,7 @@ err_unlock:
 }
 
 COMPAT_SYSCALL_DEFINE6(futex, u32 __user *, uaddr, int, op, u32, val,
-		struct compat_timespec __user *, utime, u32 __user *, uaddr2,
+		struct old_timespec32 __user *, utime, u32 __user *, uaddr2,
 		u32, val3)
 {
 	struct timespec ts;
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 625bc9897f62..8287b75ed961 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -5257,13 +5257,13 @@ SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid,
 #ifdef CONFIG_COMPAT
 COMPAT_SYSCALL_DEFINE2(sched_rr_get_interval,
 		       compat_pid_t, pid,
-		       struct compat_timespec __user *, interval)
+		       struct old_timespec32 __user *, interval)
 {
 	struct timespec64 t;
 	int retval = sched_rr_get_interval(pid, &t);
 
 	if (retval == 0)
-		retval = compat_put_timespec64(&t, interval);
+		retval = put_old_timespec32(&t, interval);
 	return retval;
 }
 #endif
diff --git a/kernel/signal.c b/kernel/signal.c
index 5843c541fda9..a4db724e14c1 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -3173,7 +3173,7 @@ SYSCALL_DEFINE4(rt_sigtimedwait, const sigset_t __user *, uthese,
 #ifdef CONFIG_COMPAT
 COMPAT_SYSCALL_DEFINE4(rt_sigtimedwait, compat_sigset_t __user *, uthese,
 		struct compat_siginfo __user *, uinfo,
-		struct compat_timespec __user *, uts, compat_size_t, sigsetsize)
+		struct old_timespec32 __user *, uts, compat_size_t, sigsetsize)
 {
 	sigset_t s;
 	struct timespec t;
diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
index e1a549c9e399..9cdd74bd2d27 100644
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -1660,7 +1660,7 @@ int nanosleep_copyout(struct restart_block *restart, struct timespec64 *ts)
 	switch(restart->nanosleep.type) {
 #ifdef CONFIG_COMPAT_32BIT_TIME
 	case TT_COMPAT:
-		if (compat_put_timespec64(ts, restart->nanosleep.compat_rmtp))
+		if (put_old_timespec32(ts, restart->nanosleep.compat_rmtp))
 			return -EFAULT;
 		break;
 #endif
@@ -1780,12 +1780,12 @@ SYSCALL_DEFINE2(nanosleep, struct __kernel_timespec __user *, rqtp,
 
 #ifdef CONFIG_COMPAT_32BIT_TIME
 
-COMPAT_SYSCALL_DEFINE2(nanosleep, struct compat_timespec __user *, rqtp,
-		       struct compat_timespec __user *, rmtp)
+COMPAT_SYSCALL_DEFINE2(nanosleep, struct old_timespec32 __user *, rqtp,
+		       struct old_timespec32 __user *, rmtp)
 {
 	struct timespec64 tu;
 
-	if (compat_get_timespec64(&tu, rqtp))
+	if (get_old_timespec32(&tu, rqtp))
 		return -EFAULT;
 
 	if (!timespec64_valid(&tu))
diff --git a/kernel/time/posix-stubs.c b/kernel/time/posix-stubs.c
index 2c6847d5d69b..989ccf028bde 100644
--- a/kernel/time/posix-stubs.c
+++ b/kernel/time/posix-stubs.c
@@ -162,20 +162,20 @@ COMPAT_SYS_NI(setitimer);
 
 #ifdef CONFIG_COMPAT_32BIT_TIME
 COMPAT_SYSCALL_DEFINE2(clock_settime, const clockid_t, which_clock,
-		       struct compat_timespec __user *, tp)
+		       struct old_timespec32 __user *, tp)
 {
 	struct timespec64 new_tp;
 
 	if (which_clock != CLOCK_REALTIME)
 		return -EINVAL;
-	if (compat_get_timespec64(&new_tp, tp))
+	if (get_old_timespec32(&new_tp, tp))
 		return -EFAULT;
 
 	return do_sys_settimeofday64(&new_tp, NULL);
 }
 
 COMPAT_SYSCALL_DEFINE2(clock_gettime, clockid_t, which_clock,
-		       struct compat_timespec __user *, tp)
+		       struct old_timespec32 __user *, tp)
 {
 	int ret;
 	struct timespec64 kernel_tp;
@@ -184,13 +184,13 @@ COMPAT_SYSCALL_DEFINE2(clock_gettime, clockid_t, which_clock,
 	if (ret)
 		return ret;
 
-	if (compat_put_timespec64(&kernel_tp, tp))
+	if (put_old_timespec32(&kernel_tp, tp))
 		return -EFAULT;
 	return 0;
 }
 
 COMPAT_SYSCALL_DEFINE2(clock_getres, clockid_t, which_clock,
-		       struct compat_timespec __user *, tp)
+		       struct old_timespec32 __user *, tp)
 {
 	struct timespec64 rtn_tp = {
 		.tv_sec = 0,
@@ -201,7 +201,7 @@ COMPAT_SYSCALL_DEFINE2(clock_getres, clockid_t, which_clock,
 	case CLOCK_REALTIME:
 	case CLOCK_MONOTONIC:
 	case CLOCK_BOOTTIME:
-		if (compat_put_timespec64(&rtn_tp, tp))
+		if (put_old_timespec32(&rtn_tp, tp))
 			return -EFAULT;
 		return 0;
 	default:
@@ -210,8 +210,8 @@ COMPAT_SYSCALL_DEFINE2(clock_getres, clockid_t, which_clock,
 }
 
 COMPAT_SYSCALL_DEFINE4(clock_nanosleep, clockid_t, which_clock, int, flags,
-		       struct compat_timespec __user *, rqtp,
-		       struct compat_timespec __user *, rmtp)
+		       struct old_timespec32 __user *, rqtp,
+		       struct old_timespec32 __user *, rmtp)
 {
 	struct timespec64 t;
 
@@ -224,7 +224,7 @@ COMPAT_SYSCALL_DEFINE4(clock_nanosleep, clockid_t, which_clock, int, flags,
 		return -EINVAL;
 	}
 
-	if (compat_get_timespec64(&t, rqtp))
+	if (get_old_timespec32(&t, rqtp))
 		return -EFAULT;
 	if (!timespec64_valid(&t))
 		return -EINVAL;
diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c
index 4b9127e95430..3e71921668ba 100644
--- a/kernel/time/posix-timers.c
+++ b/kernel/time/posix-timers.c
@@ -755,13 +755,13 @@ SYSCALL_DEFINE2(timer_gettime, timer_t, timer_id,
 #ifdef CONFIG_COMPAT_32BIT_TIME
 
 COMPAT_SYSCALL_DEFINE2(timer_gettime, timer_t, timer_id,
-		       struct compat_itimerspec __user *, setting)
+		       struct old_itimerspec32 __user *, setting)
 {
 	struct itimerspec64 cur_setting;
 
 	int ret = do_timer_gettime(timer_id, &cur_setting);
 	if (!ret) {
-		if (put_compat_itimerspec64(&cur_setting, setting))
+		if (put_old_itimerspec32(&cur_setting, setting))
 			ret = -EFAULT;
 	}
 	return ret;
@@ -928,8 +928,8 @@ SYSCALL_DEFINE4(timer_settime, timer_t, timer_id, int, flags,
 
 #ifdef CONFIG_COMPAT_32BIT_TIME
 COMPAT_SYSCALL_DEFINE4(timer_settime, timer_t, timer_id, int, flags,
-		       struct compat_itimerspec __user *, new,
-		       struct compat_itimerspec __user *, old)
+		       struct old_itimerspec32 __user *, new,
+		       struct old_itimerspec32 __user *, old)
 {
 	struct itimerspec64 new_spec, old_spec;
 	struct itimerspec64 *rtn = old ? &old_spec : NULL;
@@ -937,12 +937,12 @@ COMPAT_SYSCALL_DEFINE4(timer_settime, timer_t, timer_id, int, flags,
 
 	if (!new)
 		return -EINVAL;
-	if (get_compat_itimerspec64(&new_spec, new))
+	if (get_old_itimerspec32(&new_spec, new))
 		return -EFAULT;
 
 	error = do_timer_settime(timer_id, flags, &new_spec, rtn);
 	if (!error && old) {
-		if (put_compat_itimerspec64(&old_spec, old))
+		if (put_old_itimerspec32(&old_spec, old))
 			error = -EFAULT;
 	}
 	return error;
@@ -1115,7 +1115,7 @@ SYSCALL_DEFINE2(clock_getres, const clockid_t, which_clock,
 #ifdef CONFIG_COMPAT_32BIT_TIME
 
 COMPAT_SYSCALL_DEFINE2(clock_settime, clockid_t, which_clock,
-		       struct compat_timespec __user *, tp)
+		       struct old_timespec32 __user *, tp)
 {
 	const struct k_clock *kc = clockid_to_kclock(which_clock);
 	struct timespec64 ts;
@@ -1123,14 +1123,14 @@ COMPAT_SYSCALL_DEFINE2(clock_settime, clockid_t, which_clock,
 	if (!kc || !kc->clock_set)
 		return -EINVAL;
 
-	if (compat_get_timespec64(&ts, tp))
+	if (get_old_timespec32(&ts, tp))
 		return -EFAULT;
 
 	return kc->clock_set(which_clock, &ts);
 }
 
 COMPAT_SYSCALL_DEFINE2(clock_gettime, clockid_t, which_clock,
-		       struct compat_timespec __user *, tp)
+		       struct old_timespec32 __user *, tp)
 {
 	const struct k_clock *kc = clockid_to_kclock(which_clock);
 	struct timespec64 ts;
@@ -1141,7 +1141,7 @@ COMPAT_SYSCALL_DEFINE2(clock_gettime, clockid_t, which_clock,
 
 	err = kc->clock_get(which_clock, &ts);
 
-	if (!err && compat_put_timespec64(&ts, tp))
+	if (!err && put_old_timespec32(&ts, tp))
 		err = -EFAULT;
 
 	return err;
@@ -1180,7 +1180,7 @@ COMPAT_SYSCALL_DEFINE2(clock_adjtime, clockid_t, which_clock,
 #ifdef CONFIG_COMPAT_32BIT_TIME
 
 COMPAT_SYSCALL_DEFINE2(clock_getres, clockid_t, which_clock,
-		       struct compat_timespec __user *, tp)
+		       struct old_timespec32 __user *, tp)
 {
 	const struct k_clock *kc = clockid_to_kclock(which_clock);
 	struct timespec64 ts;
@@ -1190,7 +1190,7 @@ COMPAT_SYSCALL_DEFINE2(clock_getres, clockid_t, which_clock,
 		return -EINVAL;
 
 	err = kc->clock_getres(which_clock, &ts);
-	if (!err && tp && compat_put_timespec64(&ts, tp))
+	if (!err && tp && put_old_timespec32(&ts, tp))
 		return -EFAULT;
 
 	return err;
@@ -1237,8 +1237,8 @@ SYSCALL_DEFINE4(clock_nanosleep, const clockid_t, which_clock, int, flags,
 #ifdef CONFIG_COMPAT_32BIT_TIME
 
 COMPAT_SYSCALL_DEFINE4(clock_nanosleep, clockid_t, which_clock, int, flags,
-		       struct compat_timespec __user *, rqtp,
-		       struct compat_timespec __user *, rmtp)
+		       struct old_timespec32 __user *, rqtp,
+		       struct old_timespec32 __user *, rmtp)
 {
 	const struct k_clock *kc = clockid_to_kclock(which_clock);
 	struct timespec64 t;
@@ -1248,7 +1248,7 @@ COMPAT_SYSCALL_DEFINE4(clock_nanosleep, clockid_t, which_clock, int, flags,
 	if (!kc->nsleep)
 		return -EOPNOTSUPP;
 
-	if (compat_get_timespec64(&t, rqtp))
+	if (get_old_timespec32(&t, rqtp))
 		return -EFAULT;
 
 	if (!timespec64_valid(&t))
diff --git a/kernel/time/time.c b/kernel/time/time.c
index de332250d6fa..f1983f468fe3 100644
--- a/kernel/time/time.c
+++ b/kernel/time/time.c
@@ -104,12 +104,12 @@ SYSCALL_DEFINE1(stime, time_t __user *, tptr)
 #ifdef CONFIG_COMPAT
 #ifdef __ARCH_WANT_COMPAT_SYS_TIME
 
-/* compat_time_t is a 32 bit "long" and needs to get converted. */
-COMPAT_SYSCALL_DEFINE1(time, compat_time_t __user *, tloc)
+/* old_time32_t is a 32 bit "long" and needs to get converted. */
+COMPAT_SYSCALL_DEFINE1(time, old_time32_t __user *, tloc)
 {
-	compat_time_t i;
+	old_time32_t i;
 
-	i = (compat_time_t)ktime_get_real_seconds();
+	i = (old_time32_t)ktime_get_real_seconds();
 
 	if (tloc) {
 		if (put_user(i,tloc))
@@ -119,7 +119,7 @@ COMPAT_SYSCALL_DEFINE1(time, compat_time_t __user *, tloc)
 	return i;
 }
 
-COMPAT_SYSCALL_DEFINE1(stime, compat_time_t __user *, tptr)
+COMPAT_SYSCALL_DEFINE1(stime, old_time32_t __user *, tptr)
 {
 	struct timespec64 tv;
 	int err;
@@ -225,7 +225,7 @@ SYSCALL_DEFINE2(settimeofday, struct timeval __user *, tv,
 }
 
 #ifdef CONFIG_COMPAT
-COMPAT_SYSCALL_DEFINE2(gettimeofday, struct compat_timeval __user *, tv,
+COMPAT_SYSCALL_DEFINE2(gettimeofday, struct old_timeval32 __user *, tv,
 		       struct timezone __user *, tz)
 {
 	if (tv) {
@@ -244,7 +244,7 @@ COMPAT_SYSCALL_DEFINE2(gettimeofday, struct compat_timeval __user *, tv,
 	return 0;
 }
 
-COMPAT_SYSCALL_DEFINE2(settimeofday, struct compat_timeval __user *, tv,
+COMPAT_SYSCALL_DEFINE2(settimeofday, struct old_timeval32 __user *, tv,
 		       struct timezone __user *, tz)
 {
 	struct timespec64 new_ts;
@@ -863,10 +863,10 @@ int put_timespec64(const struct timespec64 *ts,
 }
 EXPORT_SYMBOL_GPL(put_timespec64);
 
-int __compat_get_timespec64(struct timespec64 *ts64,
-				   const struct compat_timespec __user *cts)
+int __get_old_timespec32(struct timespec64 *ts64,
+				   const struct old_timespec32 __user *cts)
 {
-	struct compat_timespec ts;
+	struct old_timespec32 ts;
 	int ret;
 
 	ret = copy_from_user(&ts, cts, sizeof(ts));
@@ -879,33 +879,33 @@ int __compat_get_timespec64(struct timespec64 *ts64,
 	return 0;
 }
 
-int __compat_put_timespec64(const struct timespec64 *ts64,
-				   struct compat_timespec __user *cts)
+int __put_old_timespec32(const struct timespec64 *ts64,
+				   struct old_timespec32 __user *cts)
 {
-	struct compat_timespec ts = {
+	struct old_timespec32 ts = {
 		.tv_sec = ts64->tv_sec,
 		.tv_nsec = ts64->tv_nsec
 	};
 	return copy_to_user(cts, &ts, sizeof(ts)) ? -EFAULT : 0;
 }
 
-int compat_get_timespec64(struct timespec64 *ts, const void __user *uts)
+int get_old_timespec32(struct timespec64 *ts, const void __user *uts)
 {
 	if (COMPAT_USE_64BIT_TIME)
 		return copy_from_user(ts, uts, sizeof(*ts)) ? -EFAULT : 0;
 	else
-		return __compat_get_timespec64(ts, uts);
+		return __get_old_timespec32(ts, uts);
 }
-EXPORT_SYMBOL_GPL(compat_get_timespec64);
+EXPORT_SYMBOL_GPL(get_old_timespec32);
 
-int compat_put_timespec64(const struct timespec64 *ts, void __user *uts)
+int put_old_timespec32(const struct timespec64 *ts, void __user *uts)
 {
 	if (COMPAT_USE_64BIT_TIME)
 		return copy_to_user(uts, ts, sizeof(*ts)) ? -EFAULT : 0;
 	else
-		return __compat_put_timespec64(ts, uts);
+		return __put_old_timespec32(ts, uts);
 }
-EXPORT_SYMBOL_GPL(compat_put_timespec64);
+EXPORT_SYMBOL_GPL(put_old_timespec32);
 
 int get_itimerspec64(struct itimerspec64 *it,
 			const struct __kernel_itimerspec __user *uit)
@@ -937,23 +937,23 @@ int put_itimerspec64(const struct itimerspec64 *it,
 }
 EXPORT_SYMBOL_GPL(put_itimerspec64);
 
-int get_compat_itimerspec64(struct itimerspec64 *its,
-			const struct compat_itimerspec __user *uits)
+int get_old_itimerspec32(struct itimerspec64 *its,
+			const struct old_itimerspec32 __user *uits)
 {
 
-	if (__compat_get_timespec64(&its->it_interval, &uits->it_interval) ||
-	    __compat_get_timespec64(&its->it_value, &uits->it_value))
+	if (__get_old_timespec32(&its->it_interval, &uits->it_interval) ||
+	    __get_old_timespec32(&its->it_value, &uits->it_value))
 		return -EFAULT;
 	return 0;
 }
-EXPORT_SYMBOL_GPL(get_compat_itimerspec64);
+EXPORT_SYMBOL_GPL(get_old_itimerspec32);
 
-int put_compat_itimerspec64(const struct itimerspec64 *its,
-			struct compat_itimerspec __user *uits)
+int put_old_itimerspec32(const struct itimerspec64 *its,
+			struct old_itimerspec32 __user *uits)
 {
-	if (__compat_put_timespec64(&its->it_interval, &uits->it_interval) ||
-	    __compat_put_timespec64(&its->it_value, &uits->it_value))
+	if (__put_old_timespec32(&its->it_interval, &uits->it_interval) ||
+	    __put_old_timespec32(&its->it_value, &uits->it_value))
 		return -EFAULT;
 	return 0;
 }
-EXPORT_SYMBOL_GPL(put_compat_itimerspec64);
+EXPORT_SYMBOL_GPL(put_old_itimerspec32);