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| author | Manfred Spraul <manfred@colorfullife.com> | 2014-06-06 14:37:47 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-06-06 16:08:15 -0700 |
| commit | 1994862dc9c16f360a9169a4d27200d15ba29713 (patch) | |
| tree | 32bce71a3486a217a3b87b86ac55f9b69e75eff6 /ipc/sem.c | |
| parent | 4bb6657dd3a55ab507502d82dbee9db276602669 (diff) | |
| download | lwn-1994862dc9c16f360a9169a4d27200d15ba29713.tar.gz lwn-1994862dc9c16f360a9169a4d27200d15ba29713.zip | |
ipc/sem.c: bugfix for semctl(,,GETZCNT)
GETZCNT is supposed to return the number of threads that wait until a
semaphore value becomes 0.
The current implementation overlooks complex operations that contain
both wait-for-zero operation and operations that alter at least one
semaphore.
The patch fixes that. It's intentionally copy&paste, this will be
cleaned up in the next patch.
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Davidlohr Bueso <davidlohr.bueso@hp.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'ipc/sem.c')
| -rw-r--r-- | ipc/sem.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/ipc/sem.c b/ipc/sem.c index fe0928a3d08b..4321fa420fe1 100644 --- a/ipc/sem.c +++ b/ipc/sem.c @@ -1047,6 +1047,16 @@ static int count_semzcnt(struct sem_array *sma, ushort semnum) && !(sops[i].sem_flg & IPC_NOWAIT)) semzcnt++; } + list_for_each_entry(q, &sma->pending_alter, list) { + struct sembuf *sops = q->sops; + int nsops = q->nsops; + int i; + for (i = 0; i < nsops; i++) + if (sops[i].sem_num == semnum + && (sops[i].sem_op == 0) + && !(sops[i].sem_flg & IPC_NOWAIT)) + semzcnt++; + } return semzcnt; } |