diff options
Diffstat (limited to 'kernel/futex.c')
| -rw-r--r-- | kernel/futex.c | 56 |
1 files changed, 51 insertions, 5 deletions
diff --git a/kernel/futex.c b/kernel/futex.c index 7ae2f50641e..600bc9d801f 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -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; @@ -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); /* @@ -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 = ¤t_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); @@ -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: |