Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 248e7357 authored by Davidlohr Bueso's avatar Davidlohr Bueso Committed by Linus Torvalds
Browse files

ipc/sem: do not call wake_sem_queue_do() prematurely ... as this call should... 

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: default avatarDavidlohr Bueso <dbueso@suse.de>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 7a5c8b57

ipc/sem.c

+12 −7
Original line number Diff line number Diff line
@@ -1887,16 +1887,22 @@ SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsops, 
	}



	error = -EFBIG;

	if (max >= sma->sem_nsems)

		goto out_rcu_wakeup;

	if (max >= sma->sem_nsems) {

		rcu_read_unlock();

		goto out_free;

	}



	error = -EACCES;

	if (ipcperms(ns, &sma->sem_perm, alter ? S_IWUGO : S_IRUGO))

		goto out_rcu_wakeup;

	if (ipcperms(ns, &sma->sem_perm, alter ? S_IWUGO : S_IRUGO)) {

		rcu_read_unlock();

		goto out_free;

	}



	error = security_sem_semop(sma, sops, nsops, alter);

	if (error)

		goto out_rcu_wakeup;

	if (error) {

		rcu_read_unlock();

		goto out_free;

	}



	error = -EIDRM;

	locknum = sem_lock(sma, sops, nsops);
@@ -2039,7 +2045,6 @@ SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsops, 


out_unlock_free:

	sem_unlock(sma, locknum);

out_rcu_wakeup:

	rcu_read_unlock();

	wake_up_sem_queue_do(&tasks);

out_free: