time: make adjtime compat handling available for 32 bit

We want to reuse the compat_timex handling on 32-bit architectures the
same way we are using the compat handling for timespec when moving to
64-bit time_t.

Move all definitions related to compat_timex out of the compat code
into the normal timekeeping code, along with a rename to old_timex32,
corresponding to the timespec/timeval structures, and make it controlled
by CONFIG_COMPAT_32BIT_TIME, which 32-bit architectures will then select.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 66 insertions, 4 deletions

diff --git a/kernel/time/time.c b/kernel/time/time.c
index 2edb5088a70b..2d013bc2b271 100644
--- a/kernel/time/time.c
+++ b/kernel/time/time.c
@@ -278,20 +278,82 @@ SYSCALL_DEFINE1(adjtimex, struct timex __user *, txc_p)
 	return copy_to_user(txc_p, &txc, sizeof(struct timex)) ? -EFAULT : ret;
 }
 
-#ifdef CONFIG_COMPAT
+#ifdef CONFIG_COMPAT_32BIT_TIME
+int get_old_timex32(struct timex *txc, const struct old_timex32 __user *utp)
+{
+	struct old_timex32 tx32;
+
+	memset(txc, 0, sizeof(struct timex));
+	if (copy_from_user(&tx32, utp, sizeof(struct old_timex32)))
+		return -EFAULT;
+
+	txc->modes = tx32.modes;
+	txc->offset = tx32.offset;
+	txc->freq = tx32.freq;
+	txc->maxerror = tx32.maxerror;
+	txc->esterror = tx32.esterror;
+	txc->status = tx32.status;
+	txc->constant = tx32.constant;
+	txc->precision = tx32.precision;
+	txc->tolerance = tx32.tolerance;
+	txc->time.tv_sec = tx32.time.tv_sec;
+	txc->time.tv_usec = tx32.time.tv_usec;
+	txc->tick = tx32.tick;
+	txc->ppsfreq = tx32.ppsfreq;
+	txc->jitter = tx32.jitter;
+	txc->shift = tx32.shift;
+	txc->stabil = tx32.stabil;
+	txc->jitcnt = tx32.jitcnt;
+	txc->calcnt = tx32.calcnt;
+	txc->errcnt = tx32.errcnt;
+	txc->stbcnt = tx32.stbcnt;
+
+	return 0;
+}
+
+int put_old_timex32(struct old_timex32 __user *utp, const struct timex *txc)
+{
+	struct old_timex32 tx32;
+
+	memset(&tx32, 0, sizeof(struct old_timex32));
+	tx32.modes = txc->modes;
+	tx32.offset = txc->offset;
+	tx32.freq = txc->freq;
+	tx32.maxerror = txc->maxerror;
+	tx32.esterror = txc->esterror;
+	tx32.status = txc->status;
+	tx32.constant = txc->constant;
+	tx32.precision = txc->precision;
+	tx32.tolerance = txc->tolerance;
+	tx32.time.tv_sec = txc->time.tv_sec;
+	tx32.time.tv_usec = txc->time.tv_usec;
+	tx32.tick = txc->tick;
+	tx32.ppsfreq = txc->ppsfreq;
+	tx32.jitter = txc->jitter;
+	tx32.shift = txc->shift;
+	tx32.stabil = txc->stabil;
+	tx32.jitcnt = txc->jitcnt;
+	tx32.calcnt = txc->calcnt;
+	tx32.errcnt = txc->errcnt;
+	tx32.stbcnt = txc->stbcnt;
+	tx32.tai = txc->tai;
+	if (copy_to_user(utp, &tx32, sizeof(struct old_timex32)))
+		return -EFAULT;
+	return 0;
+}
 
-COMPAT_SYSCALL_DEFINE1(adjtimex, struct compat_timex __user *, utp)
+COMPAT_SYSCALL_DEFINE1(adjtimex, struct old_timex32 __user *, utp)
 {
 	struct timex txc;
 	int err, ret;
 
-	err = compat_get_timex(&txc, utp);
+	err = get_old_timex32(&txc, utp);
 	if (err)
 		return err;
 
 	ret = do_adjtimex(&txc);
 
-	err = compat_put_timex(utp, &txc);
+	err = put_old_timex32(utp, &txc);
 	if (err)
 		return err;