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

diff --git a/kernel/futex.c b/kernel/futex.c
index 2268b97..49bf20a 100644 (file)
--- 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