[PATCH v2 18/29] time: make adjtime compat handling available for 32 bit

Arnd Bergmann
2019-01-18T16:18:24Z

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 | 35 ++-----------------
include/linux/time32.h | 32 ++++++++++++++++-
kernel/compat.c | 64 ----------------------------------
kernel/time/posix-timers.c | 14 ++------
kernel/time/time.c | 70 +++++++++++++++++++++++++++++++++++---
5 files changed, 102 insertions(+), 113 deletions(-)

diff --git a/include/linux/compat.h b/include/linux/compat.h
index 056be0d03722..657ca6abd855 100644
--- a/include/linux/compat.h
+++ b/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,
diff --git a/include/linux/time32.h b/include/linux/time32.h
index 118b9977080c..820a22e2b98b 100644
--- a/include/linux/time32.h
+++ b/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

diff --git a/kernel/compat.c b/kernel/compat.c
index f01affa17e22..d8a36c6ad7c9 100644
--- a/kernel/compat.c
+++ b/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)) ||
diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c
index 0e84bb72a3da..8955f32f2a36 100644
--- a/kernel/time/posix-timers.c
+++ b/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)
{
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;

--
2.20.0