From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752388AbaERIAL (ORCPT ); Sun, 18 May 2014 04:00:11 -0400 Received: from mail-ee0-f47.google.com ([74.125.83.47]:48566 "EHLO mail-ee0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751697AbaERH6w (ORCPT ); Sun, 18 May 2014 03:58:52 -0400 From: Manfred Spraul To: Andrew Morton Cc: LKML , Davidlohr Bueso , Michael Kerrisk , 1vier1@web.de, Manfred Spraul Subject: [PATCH 2/6] ipc/sem.c: Bugfix for semctl(,,GETZCNT) Date: Sun, 18 May 2014 09:58:33 +0200 Message-Id: <1400399917-17583-3-git-send-email-manfred@colorfullife.com> X-Mailer: git-send-email 1.9.0 In-Reply-To: <1400399917-17583-2-git-send-email-manfred@colorfullife.com> References: <1400399917-17583-1-git-send-email-manfred@colorfullife.com> <1400399917-17583-2-git-send-email-manfred@colorfullife.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- ipc/sem.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/ipc/sem.c b/ipc/sem.c index 5749b9c..dc648f8 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; } -- 1.9.0