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Subject[PATCH] futex: Consolidate duplicated timer setup code
Date
A new futex_setup_timer() helper function is added to consolidate all
the hrtimer_sleeper setup code.

Signed-off-by: Waiman Long <longman@redhat.com>
---
kernel/futex.c | 67 ++++++++++++++++++++++++++++----------------------
1 file changed, 37 insertions(+), 30 deletions(-)

diff --git a/kernel/futex.c b/kernel/futex.c
index a0514e01c3eb..d24679d75270 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -486,6 +486,35 @@ enum futex_access {
FUTEX_WRITE
};

+/**
+ * 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)
+ hrtimer_set_expires_range_ns(&timeout->timer, *time, range_ns);
+ else
+ hrtimer_set_expires(&timeout->timer, *time);
+
+ return timeout;
+}
+
/**
* get_futex_key() - Get parameters which are the keys for a futex
* @uaddr: virtual address of the futex
@@ -2679,7 +2708,7 @@ static int futex_wait_setup(u32 __user *uaddr, u32 val, unsigned int flags,
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;
@@ -2689,17 +2718,8 @@ 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
@@ -2779,7 +2799,7 @@ 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;
@@ -2792,13 +2812,7 @@ 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);
@@ -3182,7 +3196,7 @@ 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;
@@ -3199,15 +3213,8 @@ 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
--
2.18.1
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