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yaml
---
r: 54605
b: refs/heads/master
c: 72c1bbf
h: refs/heads/master
i:
  54603: aa241c8
v: v3
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Nick Piggin authored and Linus Torvalds committed May 8, 2007
1 parent 4953882 commit 3095386
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Showing 2 changed files with 52 additions and 6 deletions.
2 changes: 1 addition & 1 deletion [refs]
Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: 9adef58b1d4fbb58d7daed931b6790c5a3b7543a
refs/heads/master: 72c1bbf308c75a136803d2d76d0e18258be14c7a
56 changes: 51 additions & 5 deletions trunk/kernel/futex.c
Original file line number Diff line number Diff line change
Expand Up @@ -980,12 +980,15 @@ static void unqueue_me_pi(struct futex_q *q, struct futex_hash_bucket *hb)
drop_futex_key_refs(&q->key);
}

static int futex_wait(u32 __user *uaddr, u32 val, unsigned long time)
static long futex_wait_restart(struct restart_block *restart);
static int futex_wait_abstime(u32 __user *uaddr, u32 val,
int timed, unsigned long abs_time)
{
struct task_struct *curr = current;
DECLARE_WAITQUEUE(wait, curr);
struct futex_hash_bucket *hb;
struct futex_q q;
unsigned long time_left = 0;
u32 uval;
int ret;

Expand Down Expand Up @@ -1065,8 +1068,21 @@ static int futex_wait(u32 __user *uaddr, u32 val, unsigned long time)
* !list_empty() is safe here without any lock.
* q.lock_ptr != 0 is not safe, because of ordering against wakeup.
*/
if (likely(!list_empty(&q.list)))
time = schedule_timeout(time);
time_left = 0;
if (likely(!list_empty(&q.list))) {
unsigned long rel_time;

if (timed) {
unsigned long now = jiffies;
if (time_after(now, abs_time))
rel_time = 0;
else
rel_time = abs_time - now;
} else
rel_time = MAX_SCHEDULE_TIMEOUT;

time_left = schedule_timeout(rel_time);
}
__set_current_state(TASK_RUNNING);

/*
Expand All @@ -1077,13 +1093,25 @@ static int futex_wait(u32 __user *uaddr, u32 val, unsigned long time)
/* If we were woken (and unqueued), we succeeded, whatever. */
if (!unqueue_me(&q))
return 0;
if (time == 0)
if (time_left == 0)
return -ETIMEDOUT;

/*
* We expect signal_pending(current), but another thread may
* have handled it for us already.
*/
return -EINTR;
if (time_left == MAX_SCHEDULE_TIMEOUT)
return -ERESTARTSYS;
else {
struct restart_block *restart;
restart = &current_thread_info()->restart_block;
restart->fn = futex_wait_restart;
restart->arg0 = (unsigned long)uaddr;
restart->arg1 = (unsigned long)val;
restart->arg2 = (unsigned long)timed;
restart->arg3 = abs_time;
return -ERESTART_RESTARTBLOCK;
}

out_unlock_release_sem:
queue_unlock(&q, hb);
Expand All @@ -1093,6 +1121,24 @@ static int futex_wait(u32 __user *uaddr, u32 val, unsigned long time)
return ret;
}

static int futex_wait(u32 __user *uaddr, u32 val, unsigned long rel_time)
{
int timed = (rel_time != MAX_SCHEDULE_TIMEOUT);
return futex_wait_abstime(uaddr, val, timed, jiffies+rel_time);
}

static long futex_wait_restart(struct restart_block *restart)
{
u32 __user *uaddr = (u32 __user *)restart->arg0;
u32 val = (u32)restart->arg1;
int timed = (int)restart->arg2;
unsigned long abs_time = restart->arg3;

restart->fn = do_no_restart_syscall;
return (long)futex_wait_abstime(uaddr, val, timed, abs_time);
}


/*
* Userspace tried a 0 -> TID atomic transition of the futex value
* and failed. The kernel side here does the whole locking operation:
Expand Down

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