From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:42266 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753209AbdFSPVs (ORCPT ); Mon, 19 Jun 2017 11:21:48 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Paolo Cretaro , Martin Blumenstingl , Jonathan Cameron Subject: [PATCH 4.11 67/78] iio: adc: meson-saradc: fix potential crash in meson_sar_adc_clear_fifo Date: Mon, 19 Jun 2017 23:16:07 +0800 Message-Id: <20170619151031.935394642@linuxfoundation.org> In-Reply-To: <20170619151029.408399976@linuxfoundation.org> References: <20170619151029.408399976@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.11-stable review patch. If anyone has any objections, please let me know. ------------------ From: Martin Blumenstingl commit 103a07d4278203d6299798cd74cdc4d209801cac upstream. meson_sar_adc_clear_fifo passes a 0 as value-pointer to regmap_read(). In case of the meson-saradc driver this ends up in regmap_mmio_read(), where the value-pointer is de-referenced unconditionally to assign the value which was read. Fix this by passing an actual pointer, even though all we want to do is to discard the value. As a side-effect this fixes a sparse warning ("Using plain integer as NULL pointer") as reported by Paolo Cretaro. Fixes: 3adbf3427330 ("iio: adc: add a driver for the SAR ADC found in Amlogic Meson SoCs") Reported-by: Paolo Cretaro Signed-off-by: Martin Blumenstingl Signed-off-by: Jonathan Cameron Signed-off-by: Greg Kroah-Hartman --- drivers/iio/adc/meson_saradc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/iio/adc/meson_saradc.c +++ b/drivers/iio/adc/meson_saradc.c @@ -440,13 +440,13 @@ static void meson_sar_adc_unlock(struct static void meson_sar_adc_clear_fifo(struct iio_dev *indio_dev) { struct meson_sar_adc_priv *priv = iio_priv(indio_dev); - int count; + unsigned int count, tmp; for (count = 0; count < MESON_SAR_ADC_MAX_FIFO_SIZE; count++) { if (!meson_sar_adc_get_fifo_count(indio_dev)) break; - regmap_read(priv->regmap, MESON_SAR_ADC_FIFO_RD, 0); + regmap_read(priv->regmap, MESON_SAR_ADC_FIFO_RD, &tmp); } }