From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933907Ab0JSJhq (ORCPT ); Tue, 19 Oct 2010 05:37:46 -0400 Received: from mgw2.diku.dk ([130.225.96.92]:56497 "EHLO mgw2.diku.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932167Ab0JSJhZ (ORCPT ); Tue, 19 Oct 2010 05:37:25 -0400 From: Julia Lawall To: James Smart Cc: kernel-janitors@vger.kernel.org, "James E.J. Bottomley" , linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 3/4] drivers/scsi/lpfc/lpfc_bsg.c: convert nested spin_lock_irqsave to spin_lock Date: Tue, 19 Oct 2010 11:43:55 +0200 Message-Id: <1287481436-26656-3-git-send-email-julia@diku.dk> X-Mailer: git-send-email 1.7.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Julia Lawall If spin_lock_irqsave is called twice in a row with the same second argument, the interrupt state at the point of the second call overwrites the value saved by the first call. Indeed, the second call does not need to save the interrupt state, so it is changed to a simple spin_lock. The semantic match that finds this problem is as follows: (http://coccinelle.lip6.fr/) // @@ expression lock1,lock2; expression flags; @@ *spin_lock_irqsave(lock1,flags) ... when != flags *spin_lock_irqsave(lock2,flags) // Signed-off-by: Julia Lawall --- drivers/scsi/lpfc/lpfc_bsg.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/lpfc/lpfc_bsg.c b/drivers/scsi/lpfc/lpfc_bsg.c index f5d60b5..7260c3a 100644 --- a/drivers/scsi/lpfc/lpfc_bsg.c +++ b/drivers/scsi/lpfc/lpfc_bsg.c @@ -3142,12 +3142,12 @@ lpfc_bsg_menlo_cmd_cmp(struct lpfc_hba *phba, job = menlo->set_job; job->dd_data = NULL; /* so timeout handler does not reply */ - spin_lock_irqsave(&phba->hbalock, flags); + spin_lock(&phba->hbalock); cmdiocbq->iocb_flag |= LPFC_IO_WAKE; if (cmdiocbq->context2 && rspiocbq) memcpy(&((struct lpfc_iocbq *)cmdiocbq->context2)->iocb, &rspiocbq->iocb, sizeof(IOCB_t)); - spin_unlock_irqrestore(&phba->hbalock, flags); + spin_unlock(&phba->hbalock); bmp = menlo->bmp; rspiocbq = menlo->rspiocbq;