From mboxrd@z Thu Jan 1 00:00:00 1970 From: Grant Likely Subject: Re: [PATCH] spi: detect wrong transfer->len values Date: Fri, 23 Sep 2011 17:32:04 -0600 Message-ID: <20110923233204.GJ24631@ponder.secretlab.ca> References: <1316779158-12578-1-git-send-email-michael.thalmeier@hale.at> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: spi-devel-general@lists.sourceforge.net, linux-kernel@vger.kernel.org To: Michael Thalmeier Return-path: Content-Disposition: inline In-Reply-To: <1316779158-12578-1-git-send-email-michael.thalmeier@hale.at> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-spi.vger.kernel.org On Fri, Sep 23, 2011 at 01:59:18PM +0200, Michael Thalmeier wrote: > From: Helmut Raiger > > > Signed-off-by: Michael Thalmeier > --- > drivers/spi/spi.c | 12 +++++++++++- > 1 files changed, 11 insertions(+), 1 deletions(-) > > diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c > index 4d1b9f5..70adac3 100644 > --- a/drivers/spi/spi.c > +++ b/drivers/spi/spi.c > @@ -760,6 +760,17 @@ EXPORT_SYMBOL_GPL(spi_setup); > static int __spi_async(struct spi_device *spi, struct spi_message *message) > { > struct spi_master *master = spi->master; > + struct spi_transfer *xfer; > + > + /* check if number of bytes relates to bits per word mode */ > + list_for_each_entry(xfer, &message->transfers, transfer_list) { > + u8 bpw = xfer->bits_per_word ? > + xfer->bits_per_word : spi->bits_per_word; > + > + if ((bpw == 16 && (xfer->len & 1)) || > + (bpw == 32 && (xfer->len & 3))) > + return -EINVAL; > + } Rather than turning this into a hard fail; you should make it a WARN_ONCE(). I wouldn't be surprised if a lot of drivers have the bad behaviour, and applying this patch could have far reaching consequences, including boards failing to boot. g. > > /* Half-duplex links include original MicroWire, and ones with > * only one data pin like SPI_3WIRE (switches direction) or where > @@ -768,7 +779,6 @@ static int __spi_async(struct spi_device *spi, struct spi_message *message) > */ > if ((master->flags & SPI_MASTER_HALF_DUPLEX) > || (spi->mode & SPI_3WIRE)) { > - struct spi_transfer *xfer; Unrelated change? > unsigned flags = master->flags; > > list_for_each_entry(xfer, &message->transfers, transfer_list) { > -- > 1.7.6.2 > > > > -- > Scanned by MailScanner. >