Messages in this thread Patch in this message | | | From | Manfred Spraul <> | Subject | [PATCH 2/3] ipc/sem.c: handle spurious wakeups | Date | Sat, 24 Sep 2011 19:37:11 +0200 |
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semtimedop() does not handle spurious wakeups, it returns -EINTR to user space. Most other schedule() users would just loop and not return to user space. The patch adds such a loop to semtimedop()
Reported-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Manfred Spraul <manfred@colorfullife.com> --- ipc/sem.c | 9 +++++++++ 1 files changed, 9 insertions(+), 0 deletions(-)
diff --git a/ipc/sem.c b/ipc/sem.c index fb13be1..227948f 100644 --- a/ipc/sem.c +++ b/ipc/sem.c @@ -1426,6 +1426,8 @@ SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsops, queue.status = -EINTR; queue.sleeper = current; + +sleep_again: current->state = TASK_INTERRUPTIBLE; sem_unlock(sma); @@ -1478,6 +1480,13 @@ SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsops, */ if (timeout && jiffies_left == 0) error = -EAGAIN; + + /* + * If the wakeup was spurious, just retry + */ + if (error == -EINTR && !signal_pending(current)) + goto sleep_again; + unlink_queue(sma, &queue); out_unlock_free: -- 1.7.6
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