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>

include/linux/compat.h

@@ -132,37 +132,6 @@ struct compat_tms {
 	compat_clock_t		tms_cstime;
 };
 
-struct compat_timex {
-	compat_uint_t modes;
-	compat_long_t offset;
-	compat_long_t freq;
-	compat_long_t maxerror;
-	compat_long_t esterror;
-	compat_int_t status;
-	compat_long_t constant;
-	compat_long_t precision;
-	compat_long_t tolerance;
-	struct old_timeval32 time;
-	compat_long_t tick;
-	compat_long_t ppsfreq;
-	compat_long_t jitter;
-	compat_int_t shift;
-	compat_long_t stabil;
-	compat_long_t jitcnt;
-	compat_long_t calcnt;
-	compat_long_t errcnt;
-	compat_long_t stbcnt;
-	compat_int_t tai;
-
-	compat_int_t:32; compat_int_t:32; compat_int_t:32; compat_int_t:32;
-	compat_int_t:32; compat_int_t:32; compat_int_t:32; compat_int_t:32;
-	compat_int_t:32; compat_int_t:32; compat_int_t:32;
-};
-
-struct timex;
-int compat_get_timex(struct timex *, const struct compat_timex __user *);
-int compat_put_timex(struct compat_timex __user *, const struct timex *);
-
 #define _COMPAT_NSIG_WORDS	(_COMPAT_NSIG / _COMPAT_NSIG_BPW)
 
 typedef struct {
@@ -808,7 +777,7 @@ asmlinkage long compat_sys_gettimeofday(struct old_timeval32 __user *tv,
 		struct timezone __user *tz);
 asmlinkage long compat_sys_settimeofday(struct old_timeval32 __user *tv,
 		struct timezone __user *tz);
-asmlinkage long compat_sys_adjtimex(struct compat_timex __user *utp);
+asmlinkage long compat_sys_adjtimex(struct old_timex32 __user *utp);
 
 /* kernel/timer.c */
 asmlinkage long compat_sys_sysinfo(struct compat_sysinfo __user *info);
@@ -911,7 +880,7 @@ asmlinkage long compat_sys_open_by_handle_at(int mountdirfd,
 					     struct file_handle __user *handle,
 					     int flags);
 asmlinkage long compat_sys_clock_adjtime(clockid_t which_clock,
-					 struct compat_timex __user *tp);
+					 struct old_timex32 __user *tp);
 asmlinkage long compat_sys_sendmmsg(int fd, struct compat_mmsghdr __user *mmsg,
 				    unsigned vlen, unsigned int flags);
 asmlinkage ssize_t compat_sys_process_vm_readv(compat_pid_t pid,

include/linux/time32.h

@@ -10,6 +10,7 @@
  */
 
 #include <linux/time64.h>
+#include <linux/timex.h>
 
 #define TIME_T_MAX	(time_t)((1UL << ((sizeof(time_t) << 3) - 1)) - 1)
 
@@ -35,13 +36,42 @@ struct old_utimbuf32 {
 	old_time32_t	modtime;
 };
 
+struct old_timex32 {
+	u32 modes;
+	s32 offset;
+	s32 freq;
+	s32 maxerror;
+	s32 esterror;
+	s32 status;
+	s32 constant;
+	s32 precision;
+	s32 tolerance;
+	struct old_timeval32 time;
+	s32 tick;
+	s32 ppsfreq;
+	s32 jitter;
+	s32 shift;
+	s32 stabil;
+	s32 jitcnt;
+	s32 calcnt;
+	s32 errcnt;
+	s32 stbcnt;
+	s32 tai;
+
+	s32:32; s32:32; s32:32; s32:32;
+	s32:32; s32:32; s32:32; s32:32;
+	s32:32; s32:32; s32:32;
+};
+
 extern int get_old_timespec32(struct timespec64 *, const void __user *);
 extern int put_old_timespec32(const struct timespec64 *, void __user *);
 extern int get_old_itimerspec32(struct itimerspec64 *its,
 			const struct old_itimerspec32 __user *uits);
 extern int put_old_itimerspec32(const struct itimerspec64 *its,
 			struct old_itimerspec32 __user *uits);
-
+struct timex;
+int get_old_timex32(struct timex *, const struct old_timex32 __user *);
+int put_old_timex32(struct old_timex32 __user *, const struct timex *);
 
 #if __BITS_PER_LONG == 64
 

kernel/compat.c

@@ -20,7 +20,6 @@
 #include <linux/syscalls.h>
 #include <linux/unistd.h>
 #include <linux/security.h>
-#include <linux/timex.h>
 #include <linux/export.h>
 #include <linux/migrate.h>
 #include <linux/posix-timers.h>
@@ -30,69 +29,6 @@
 
 #include <linux/uaccess.h>
 
-int compat_get_timex(struct timex *txc, const struct compat_timex __user *utp)
-{
-	struct compat_timex tx32;
-
-	memset(txc, 0, sizeof(struct timex));
-	if (copy_from_user(&tx32, utp, sizeof(struct compat_timex)))
-		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 compat_put_timex(struct compat_timex __user *utp, const struct timex *txc)
-{
-	struct compat_timex tx32;
-
-	memset(&tx32, 0, sizeof(struct compat_timex));
-	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 compat_timex)))
-		return -EFAULT;
-	return 0;
-}
-
 static int __compat_get_timeval(struct timeval *tv, const struct old_timeval32 __user *ctv)
 {
 	return (!access_ok(ctv, sizeof(*ctv)) ||

kernel/time/posix-timers.c

@@ -1123,12 +1123,8 @@ COMPAT_SYSCALL_DEFINE2(clock_gettime, clockid_t, which_clock,
 	return err;
 }
 
-#endif
-
-#ifdef CONFIG_COMPAT
-
 COMPAT_SYSCALL_DEFINE2(clock_adjtime, clockid_t, which_clock,
-		       struct compat_timex __user *, utp)
+		       struct old_timex32 __user *, utp)
 {
 	const struct k_clock *kc = clockid_to_kclock(which_clock);
 	struct timex ktx;
@@ -1139,22 +1135,18 @@ COMPAT_SYSCALL_DEFINE2(clock_adjtime, clockid_t, which_clock,
 	if (!kc->clock_adj)
 		return -EOPNOTSUPP;
 
-	err = compat_get_timex(&ktx, utp);
+	err = get_old_timex32(&ktx, utp);
 	if (err)
 		return err;
 
 	err = kc->clock_adj(which_clock, &ktx);
 
 	if (err >= 0)
-		err = compat_put_timex(utp, &ktx);
+		err = put_old_timex32(utp, &ktx);
 
 	return err;
 }
 
-#endif
-
-#ifdef CONFIG_COMPAT_32BIT_TIME
-
 COMPAT_SYSCALL_DEFINE2(clock_getres, clockid_t, which_clock,
 		       struct old_timespec32 __user *, tp)
 {

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;