Cleanup non-arch xtime uses, use get_seconds() or current_kernel_time().

This avoids use of the kernel-internal "xtime" variable directly outside
of the actual time-related functions.  Instead, use the helper functions
that we already have available to us.

This doesn't actually change any behaviour, but this will allow us to
fix the fact that "xtime" isn't updated very often with CONFIG_NO_HZ
(because much of the realtime information is maintained as separate
offsets to 'xtime'), which has caused interfaces that use xtime directly
to get a time that is out of sync with the real-time clock by up to a
third of a second or so.

Signed-off-by: John Stultz <johnstul@us.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

13 files changed, 34 insertions, 33 deletions

diff --git a/drivers/rtc/class.c b/drivers/rtc/class.c
index 8b3cd31d6a61..10ab3b71ffc6 100644
--- a/drivers/rtc/class.c
+++ b/drivers/rtc/class.c
@@ -46,6 +46,7 @@ static int rtc_suspend(struct device *dev, pm_message_t mesg)
 {
         struct rtc_device       *rtc = to_rtc_device(dev);
         struct rtc_time         tm;
+        struct timespec         ts = current_kernel_time();
 
         if (strncmp(rtc->dev.bus_id,
                                 CONFIG_RTC_HCTOSYS_DEVICE,
@@ -57,8 +58,8 @@ static int rtc_suspend(struct device *dev, pm_message_t mesg)
 
         /* RTC precision is 1 second; adjust delta for avg 1/2 sec err */
         set_normalized_timespec(&delta,
-                                xtime.tv_sec - oldtime,
-                                xtime.tv_nsec - (NSEC_PER_SEC >> 1));
+                                ts.tv_sec - oldtime,
+                                ts.tv_nsec - (NSEC_PER_SEC >> 1));
 
         return 0;
 }
diff --git a/drivers/s390/net/ctcmain.c b/drivers/s390/net/ctcmain.c
index b20fd0681733..92e8a37b5022 100644
--- a/drivers/s390/net/ctcmain.c
+++ b/drivers/s390/net/ctcmain.c
@@ -674,7 +674,7 @@ ch_action_txdone(fsm_instance * fi, int event, void *arg)
         int first = 1;
         int i;
         unsigned long duration;
-        struct timespec done_stamp = xtime;
+        struct timespec done_stamp = current_kernel_time();
 
         DBF_TEXT(trace, 4, __FUNCTION__);
 
@@ -730,7 +730,7 @@ ch_action_txdone(fsm_instance * fi, int event, void *arg)
                 spin_unlock(&ch->collect_lock);
                 ch->ccw[1].count = ch->trans_skb->len;
                 fsm_addtimer(&ch->timer, CTC_TIMEOUT_5SEC, CH_EVENT_TIMER, ch);
-                ch->prof.send_stamp = xtime;
+                ch->prof.send_stamp = current_kernel_time();
                 rc = ccw_device_start(ch->cdev, &ch->ccw[0],
                                       (unsigned long) ch, 0xff, 0);
                 ch->prof.doios_multi++;
@@ -2281,7 +2281,7 @@ transmit_skb(struct channel *ch, struct sk_buff *skb)
                 fsm_newstate(ch->fsm, CH_STATE_TX);
                 fsm_addtimer(&ch->timer, CTC_TIMEOUT_5SEC, CH_EVENT_TIMER, ch);
                 spin_lock_irqsave(get_ccwdev_lock(ch->cdev), saveflags);
-                ch->prof.send_stamp = xtime;
+                ch->prof.send_stamp = current_kernel_time();
                 rc = ccw_device_start(ch->cdev, &ch->ccw[ccw_idx],
                                       (unsigned long) ch, 0xff, 0);
                 spin_unlock_irqrestore(get_ccwdev_lock(ch->cdev), saveflags);
diff --git a/drivers/s390/net/netiucv.c b/drivers/s390/net/netiucv.c
index 3d28e1a5bf79..268889474339 100644
--- a/drivers/s390/net/netiucv.c
+++ b/drivers/s390/net/netiucv.c
@@ -753,7 +753,7 @@ static void conn_action_txdone(fsm_instance *fi, int event, void *arg)
 
         header.next = 0;
         memcpy(skb_put(conn->tx_buff, NETIUCV_HDRLEN), &header, NETIUCV_HDRLEN);
-        conn->prof.send_stamp = xtime;
+        conn->prof.send_stamp = current_kernel_time();
         txmsg.class = 0;
         txmsg.tag = 0;
         rc = iucv_message_send(conn->path, &txmsg, 0, 0,
@@ -1185,7 +1185,7 @@ static int netiucv_transmit_skb(struct iucv_connection *conn,
                 memcpy(skb_put(nskb, NETIUCV_HDRLEN), &header,  NETIUCV_HDRLEN);
 
                 fsm_newstate(conn->fsm, CONN_STATE_TX);
-                conn->prof.send_stamp = xtime;
+                conn->prof.send_stamp = current_kernel_time();
 
                 msg.tag = 1;
                 msg.class = 0;
diff --git a/include/linux/time.h b/include/linux/time.h
index e6aea5146e5d..71181df8b744 100644
--- a/include/linux/time.h
+++ b/include/linux/time.h
@@ -107,7 +107,7 @@ static inline unsigned long get_seconds(void)
 struct timespec current_kernel_time(void);
 
 #define CURRENT_TIME            (current_kernel_time())
-#define CURRENT_TIME_SEC        ((struct timespec) { xtime.tv_sec, 0 })
+#define CURRENT_TIME_SEC        ((struct timespec) { get_seconds(), 0 })
 
 extern void do_gettimeofday(struct timeval *tv);
 extern int do_settimeofday(struct timespec *tv);
diff --git a/kernel/acct.c b/kernel/acct.c
index 70d0d88e5554..24f0f8b2ba72 100644
--- a/kernel/acct.c
+++ b/kernel/acct.c
@@ -468,7 +468,7 @@ static void do_acct_process(struct file *file)
         }
 #endif
         do_div(elapsed, AHZ);
-        ac.ac_btime = xtime.tv_sec - elapsed;
+        ac.ac_btime = get_seconds() - elapsed;
         /* we really need to bite the bullet and change layout */
         ac.ac_uid = current->uid;
         ac.ac_gid = current->gid;
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index eb1ddebd2c04..a7bb05e6cb63 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -144,7 +144,7 @@ static void hrtimer_get_softirq_time(struct hrtimer_cpu_base *base)
 #ifdef CONFIG_NO_HZ
                 getnstimeofday(&xts);
 #else
-                xts = xtime;
+                xts = current_kernel_time();
 #endif
                 tom = wall_to_monotonic;
         } while (read_seqretry(&xtime_lock, seq));
diff --git a/kernel/time.c b/kernel/time.c
index 5b81da08bbdb..2289a8d68314 100644
--- a/kernel/time.c
+++ b/kernel/time.c
@@ -215,22 +215,6 @@ asmlinkage long sys_adjtimex(struct timex __user *txc_p)
         return copy_to_user(txc_p, &txc, sizeof(struct timex)) ? -EFAULT : ret;
 }
 
-inline struct timespec current_kernel_time(void)
-{
-        struct timespec now;
-        unsigned long seq;
-
-        do {
-                seq = read_seqbegin(&xtime_lock);
-                
-                now = xtime;
-        } while (read_seqretry(&xtime_lock, seq));
-
-        return now; 
-}
-
-EXPORT_SYMBOL(current_kernel_time);
-
 /**
  * current_fs_time - Return FS time
  * @sb: Superblock.
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 88c81026e003..07a3f1420c27 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -509,3 +509,19 @@ void monotonic_to_bootbased(struct timespec *ts)
 {
         ts->tv_sec += total_sleep_time;
 }
+
+struct timespec current_kernel_time(void)
+{
+        struct timespec now;
+        unsigned long seq;
+
+        do {
+                seq = read_seqbegin(&xtime_lock);
+
+                now = xtime;
+        } while (read_seqretry(&xtime_lock, seq));
+
+        return now;
+}
+
+EXPORT_SYMBOL(current_kernel_time);
diff --git a/kernel/tsacct.c b/kernel/tsacct.c
index 658f638c402c..c122131a122f 100644
--- a/kernel/tsacct.c
+++ b/kernel/tsacct.c
@@ -39,7 +39,7 @@ void bacct_add_tsk(struct taskstats *stats, struct task_struct *tsk)
         ac_etime = timespec_to_ns(&ts);
         do_div(ac_etime, NSEC_PER_USEC);
         stats->ac_etime = ac_etime;
-        stats->ac_btime = xtime.tv_sec - ts.tv_sec;
+        stats->ac_btime = get_seconds() - ts.tv_sec;
         if (thread_group_leader(tsk)) {
                 stats->ac_exitcode = tsk->exit_code;
                 if (tsk->flags & PF_FORKNOEXEC)
diff --git a/net/rxrpc/af_rxrpc.c b/net/rxrpc/af_rxrpc.c
index 16a68df4e36b..c58fa0d1be26 100644
--- a/net/rxrpc/af_rxrpc.c
+++ b/net/rxrpc/af_rxrpc.c
@@ -787,7 +787,7 @@ static int __init af_rxrpc_init(void)
 
         BUILD_BUG_ON(sizeof(struct rxrpc_skb_priv) > sizeof(dummy_skb->cb));
 
-        rxrpc_epoch = htonl(xtime.tv_sec);
+        rxrpc_epoch = htonl(get_seconds());
 
         ret = -ENOMEM;
         rxrpc_call_jar = kmem_cache_create(
diff --git a/net/rxrpc/ar-connection.c b/net/rxrpc/ar-connection.c
index 482750efc235..372b24466dc7 100644
--- a/net/rxrpc/ar-connection.c
+++ b/net/rxrpc/ar-connection.c
@@ -791,7 +791,7 @@ void rxrpc_put_connection(struct rxrpc_connection *conn)
 
         ASSERTCMP(atomic_read(&conn->usage), >, 0);
 
-        conn->put_time = xtime.tv_sec;
+        conn->put_time = get_seconds();
         if (atomic_dec_and_test(&conn->usage)) {
                 _debug("zombie");
                 rxrpc_queue_delayed_work(&rxrpc_connection_reap, 0);
@@ -835,7 +835,7 @@ void rxrpc_connection_reaper(struct work_struct *work)
 
         _enter("");
 
-        now = xtime.tv_sec;
+        now = get_seconds();
         earliest = ULONG_MAX;
 
         write_lock_bh(&rxrpc_connection_lock);
diff --git a/net/rxrpc/ar-transport.c b/net/rxrpc/ar-transport.c
index d43d78f19302..bb282a6a19f0 100644
--- a/net/rxrpc/ar-transport.c
+++ b/net/rxrpc/ar-transport.c
@@ -183,7 +183,7 @@ void rxrpc_put_transport(struct rxrpc_transport *trans)
 
         ASSERTCMP(atomic_read(&trans->usage), >, 0);
 
-        trans->put_time = xtime.tv_sec;
+        trans->put_time = get_seconds();
         if (unlikely(atomic_dec_and_test(&trans->usage)))
                 _debug("zombie");
                 /* let the reaper determine the timeout to avoid a race with
@@ -219,7 +219,7 @@ static void rxrpc_transport_reaper(struct work_struct *work)
 
         _enter("");
 
-        now = xtime.tv_sec;
+        now = get_seconds();
         earliest = ULONG_MAX;
 
         /* extract all the transports that have been dead too long */
diff --git a/net/rxrpc/rxkad.c b/net/rxrpc/rxkad.c
index 5ec705144e10..ac3cabdca78c 100644
--- a/net/rxrpc/rxkad.c
+++ b/net/rxrpc/rxkad.c
@@ -916,7 +916,7 @@ static int rxkad_decrypt_ticket(struct rxrpc_connection *conn,
                 issue = be32_to_cpu(stamp);
         }
         p += 4;
-        now = xtime.tv_sec;
+        now = get_seconds();
         _debug("KIV ISSUE: %lx [%lx]", issue, now);
 
         /* check the ticket is in date */