From mboxrd@z Thu Jan 1 00:00:00 1970 From: Borislav Petkov Subject: Re: [PATCH v2 -mm 4/6] ide: avoid DMA on the stack for REQ_TYPE_ATA_PC Date: Mon, 2 Jun 2008 21:14:10 +0200 Message-ID: <20080602191410.GA15555@gollum.tnic> References: <1212389852-1277-1-git-send-email-fujita.tomonori@lab.ntt.co.jp> <1212389852-1277-2-git-send-email-fujita.tomonori@lab.ntt.co.jp> <1212389852-1277-3-git-send-email-fujita.tomonori@lab.ntt.co.jp> <1212389852-1277-4-git-send-email-fujita.tomonori@lab.ntt.co.jp> <1212389852-1277-5-git-send-email-fujita.tomonori@lab.ntt.co.jp> Reply-To: petkovbb@gmail.com Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Content-Disposition: inline In-Reply-To: <1212389852-1277-5-git-send-email-fujita.tomonori@lab.ntt.co.jp> Sender: linux-scsi-owner@vger.kernel.org To: FUJITA Tomonori Cc: linux-scsi@vger.kernel.org, linux-ide@vger.kernel.org, jens.axboe@oracle.com, tsbogend@alpha.franken.de, bzolnier@gmail.com, James.Bottomley@HansenPartnership.com, jeff@garzik.org, davem@davemloft.net, akpm@linux-foundation.org List-Id: linux-ide@vger.kernel.org On Mon, Jun 02, 2008 at 03:57:30PM +0900, FUJITA Tomonori wrote: > Some REQ_TYPE_ATA_PC commands uses the stack buffers for DMA, which > leads to memory corruption on a non-coherent platform. >=20 > With regard to alignment and padding, ide-cd has the the dma safe > check for sg requests and REQ_TYPE_ATA_PC. This adds the stack buffer > check to that check. >=20 > Signed-off-by: FUJITA Tomonori > Cc: Borislav Petkov > Cc: Bartlomiej Zolnierkiewicz > --- > drivers/ide/ide-cd.c | 5 +++++ > 1 files changed, 5 insertions(+), 0 deletions(-) >=20 > diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c > index e3f085c..e12d602 100644 > --- a/drivers/ide/ide-cd.c > +++ b/drivers/ide/ide-cd.c > @@ -1195,6 +1195,7 @@ static ide_startstop_t cdrom_do_block_pc(ide_dr= ive_t *drive, struct request *rq) > struct request_queue *q =3D drive->queue; > unsigned int alignment; > unsigned long addr; > + unsigned long stack_mask =3D ~(THREAD_SIZE - 1); > =20 > if (rq->bio) > addr =3D (unsigned long)bio_data(rq->bio); > @@ -1212,6 +1213,10 @@ static ide_startstop_t cdrom_do_block_pc(ide_d= rive_t *drive, struct request *rq) > alignment =3D queue_dma_alignment(q) | q->dma_pad_mask; > if (addr & alignment || rq->data_len & alignment) > info->dma =3D 0; > + > + if (!((addr & stack_mask) ^ > + ((unsigned long)current->stack & stack_mask))) > + info->dma =3D 0; > } > =20 > /* start sending the command to the drive */ > --=20 > 1.5.4.2 Looks good, thanks. Acked-by: Borislav Petkov --=20 Regards/Gru=DF, Boris. -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html