futex: Consolidate duplicated timer setup code

Add a new futex_setup_timer() helper function to consolidate all the
hrtimer_sleeper setup code.

Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Darren Hart <dvhart@infradead.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Link: https://lkml.kernel.org/r/20190528160345.24017-1-longman@redhat.com

1 files changed, 39 insertions, 30 deletions

diff --git a/kernel/futex.c b/kernel/futex.c
index 2268b97d5439..49bf20a8c512 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -484,6 +484,37 @@ enum futex_access {
 };
 
 /**
+ * futex_setup_timer - set up the sleeping hrtimer.
+ * @time:       ptr to the given timeout value
+ * @timeout:    the hrtimer_sleeper structure to be set up
+ * @flags:      futex flags
+ * @range_ns:   optional range in ns
+ *
+ * Return: Initialized hrtimer_sleeper structure or NULL if no timeout
+ *         value given
+ */
+static inline struct hrtimer_sleeper *
+futex_setup_timer(ktime_t *time, struct hrtimer_sleeper *timeout,
+                  int flags, u64 range_ns)
+{
+        if (!time)
+                return NULL;
+
+        hrtimer_init_on_stack(&timeout->timer, (flags & FLAGS_CLOCKRT) ?
+                              CLOCK_REALTIME : CLOCK_MONOTONIC,
+                              HRTIMER_MODE_ABS);
+        hrtimer_init_sleeper(timeout, current);
+
+        /*
+         * If range_ns is 0, calling hrtimer_set_expires_range_ns() is
+         * effectively the same as calling hrtimer_set_expires().
+         */
+        hrtimer_set_expires_range_ns(&timeout->timer, *time, range_ns);
+
+        return timeout;
+}
+
+/**
  * get_futex_key() - Get parameters which are the keys for a futex
  * @uaddr:      virtual address of the futex
  * @fshared:    0 for a PROCESS_PRIVATE futex, 1 for PROCESS_SHARED
@@ -2692,7 +2723,7 @@ out:
 static int futex_wait(u32 __user *uaddr, unsigned int flags, u32 val,
                       ktime_t *abs_time, u32 bitset)
 {
-        struct hrtimer_sleeper timeout, *to = NULL;
+        struct hrtimer_sleeper timeout, *to;
         struct restart_block *restart;
         struct futex_hash_bucket *hb;
         struct futex_q q = futex_q_init;
@@ -2702,17 +2733,8 @@ static int futex_wait(u32 __user *uaddr, unsigned int flags, u32 val,
                 return -EINVAL;
         q.bitset = bitset;
 
-        if (abs_time) {
-                to = &timeout;
-
-                hrtimer_init_on_stack(&to->timer, (flags & FLAGS_CLOCKRT) ?
-                                      CLOCK_REALTIME : CLOCK_MONOTONIC,
-                                      HRTIMER_MODE_ABS);
-                hrtimer_init_sleeper(to, current);
-                hrtimer_set_expires_range_ns(&to->timer, *abs_time,
-                                             current->timer_slack_ns);
-        }
-
+        to = futex_setup_timer(abs_time, &timeout, flags,
+                               current->timer_slack_ns);
 retry:
         /*
          * Prepare to wait on uaddr. On success, holds hb lock and increments
@@ -2792,7 +2814,7 @@ static long futex_wait_restart(struct restart_block *restart)
 static int futex_lock_pi(u32 __user *uaddr, unsigned int flags,
                          ktime_t *time, int trylock)
 {
-        struct hrtimer_sleeper timeout, *to = NULL;
+        struct hrtimer_sleeper timeout, *to;
         struct futex_pi_state *pi_state = NULL;
         struct rt_mutex_waiter rt_waiter;
         struct futex_hash_bucket *hb;
@@ -2805,13 +2827,7 @@ static int futex_lock_pi(u32 __user *uaddr, unsigned int flags,
         if (refill_pi_state_cache())
                 return -ENOMEM;
 
-        if (time) {
-                to = &timeout;
-                hrtimer_init_on_stack(&to->timer, CLOCK_REALTIME,
-                                      HRTIMER_MODE_ABS);
-                hrtimer_init_sleeper(to, current);
-                hrtimer_set_expires(&to->timer, *time);
-        }
+        to = futex_setup_timer(time, &timeout, FLAGS_CLOCKRT, 0);
 
 retry:
         ret = get_futex_key(uaddr, flags & FLAGS_SHARED, &q.key, FUTEX_WRITE);
@@ -3208,7 +3224,7 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags,
                                  u32 val, ktime_t *abs_time, u32 bitset,
                                  u32 __user *uaddr2)
 {
-        struct hrtimer_sleeper timeout, *to = NULL;
+        struct hrtimer_sleeper timeout, *to;
         struct futex_pi_state *pi_state = NULL;
         struct rt_mutex_waiter rt_waiter;
         struct futex_hash_bucket *hb;
@@ -3225,15 +3241,8 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags,
         if (!bitset)
                 return -EINVAL;
 
-        if (abs_time) {
-                to = &timeout;
-                hrtimer_init_on_stack(&to->timer, (flags & FLAGS_CLOCKRT) ?
-                                      CLOCK_REALTIME : CLOCK_MONOTONIC,
-                                      HRTIMER_MODE_ABS);
-                hrtimer_init_sleeper(to, current);
-                hrtimer_set_expires_range_ns(&to->timer, *abs_time,
-                                             current->timer_slack_ns);
-        }
+        to = futex_setup_timer(abs_time, &timeout, flags,
+                               current->timer_slack_ns);
 
         /*
          * The waiter is allocated on our stack, manipulated by the requeue