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ipc/sem: do not call wake_sem_queue_do() prematurely ... as this call should obviously be paired with its _prepare()
counterpart. At least whenever possible, as there is no harm in calling it bogusly as we do now in a few places. Immediate error semop(2) paths that are far from ever having the task block can be simplified and avoid a few unnecessary loads on their way out of the call as it is not deeply nested. Link: http://lkml.kernel.org/r/1474225896-10066-2-git-send-email-dave@stgolabs.net Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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parent
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19
ipc/sem.c
19
ipc/sem.c
@ -1887,16 +1887,22 @@ SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsops,
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}
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error = -EFBIG;
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if (max >= sma->sem_nsems)
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goto out_rcu_wakeup;
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if (max >= sma->sem_nsems) {
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rcu_read_unlock();
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goto out_free;
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}
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error = -EACCES;
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if (ipcperms(ns, &sma->sem_perm, alter ? S_IWUGO : S_IRUGO))
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goto out_rcu_wakeup;
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if (ipcperms(ns, &sma->sem_perm, alter ? S_IWUGO : S_IRUGO)) {
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rcu_read_unlock();
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goto out_free;
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}
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error = security_sem_semop(sma, sops, nsops, alter);
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if (error)
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goto out_rcu_wakeup;
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if (error) {
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rcu_read_unlock();
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goto out_free;
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}
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error = -EIDRM;
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locknum = sem_lock(sma, sops, nsops);
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@ -2039,7 +2045,6 @@ sleep_again:
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out_unlock_free:
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sem_unlock(sma, locknum);
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out_rcu_wakeup:
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rcu_read_unlock();
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wake_up_sem_queue_do(&tasks);
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out_free:
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