From mboxrd@z Thu Jan 1 00:00:00 1970 From: Inki Dae Subject: Re: [PATCH] drm/exynos: Avoid NULL pointer dereference in resume if bind failed Date: Wed, 30 Sep 2015 20:26:37 +0900 Message-ID: <560BC6ED.3090205@samsung.com> References: <1443370306-15429-1-git-send-email-ckeepax@opensource.wolfsonmicro.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mailout1.samsung.com ([203.254.224.24]:54391 "EHLO mailout1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932661AbbI3L0j (ORCPT ); Wed, 30 Sep 2015 07:26:39 -0400 Received: from epcpsbgr5.samsung.com (u145.gpu120.samsung.co.kr [203.254.230.145]) by mailout1.samsung.com (Oracle Communications Messaging Server 7.0.5.31.0 64bit (built May 5 2014)) with ESMTP id <0NVH02U4TMGD1UB0@mailout1.samsung.com> for linux-samsung-soc@vger.kernel.org; Wed, 30 Sep 2015 20:26:37 +0900 (KST) In-reply-to: <1443370306-15429-1-git-send-email-ckeepax@opensource.wolfsonmicro.com> Sender: linux-samsung-soc-owner@vger.kernel.org List-Id: linux-samsung-soc@vger.kernel.org To: Charles Keepax , jingoohan1@gmail.com Cc: jy0922.shim@samsung.com, sw0312.kim@samsung.com, kyungmin.park@samsung.com, airlied@linux.ie, kgene@kernel.org, k.kozlowski@samsung.com, dri-devel@lists.freedesktop.org, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org Hi, On 2015=EB=85=84 09=EC=9B=94 28=EC=9D=BC 01:11, Charles Keepax wrote: > If binding failed calling exynos_dp_enable in exynos_dp_resume will > result in several NULL pointer dereferences. It is much better to > simply skip suspend/resume handling if bind has failed, do so by > checking if a drm_dev exists. Thanks for your patch. However, the pm interfaces of KMS drivers aren't required because these are controlled by top of Exynos drm driver and connector dpms. So I posted a patch that it removes pm interfaces of dp driver. Thanks, Inki Dae >=20 > Signed-off-by: Charles Keepax > --- > drivers/gpu/drm/exynos/exynos_dp_core.c | 6 ++++++ > 1 files changed, 6 insertions(+), 0 deletions(-) >=20 > diff --git a/drivers/gpu/drm/exynos/exynos_dp_core.c b/drivers/gpu/dr= m/exynos/exynos_dp_core.c > index d66ade0..48baf07 100644 > --- a/drivers/gpu/drm/exynos/exynos_dp_core.c > +++ b/drivers/gpu/drm/exynos/exynos_dp_core.c > @@ -1388,6 +1388,9 @@ static int exynos_dp_suspend(struct device *dev= ) > { > struct exynos_dp_device *dp =3D dev_get_drvdata(dev); > =20 > + if (!dp->drm_dev) > + return 0; > + > exynos_dp_disable(&dp->encoder); > return 0; > } > @@ -1396,6 +1399,9 @@ static int exynos_dp_resume(struct device *dev) > { > struct exynos_dp_device *dp =3D dev_get_drvdata(dev); > =20 > + if (!dp->drm_dev) > + return 0; > + > exynos_dp_enable(&dp->encoder); > return 0; > } >=20 From mboxrd@z Thu Jan 1 00:00:00 1970 From: inki.dae@samsung.com (Inki Dae) Date: Wed, 30 Sep 2015 20:26:37 +0900 Subject: [PATCH] drm/exynos: Avoid NULL pointer dereference in resume if bind failed In-Reply-To: <1443370306-15429-1-git-send-email-ckeepax@opensource.wolfsonmicro.com> References: <1443370306-15429-1-git-send-email-ckeepax@opensource.wolfsonmicro.com> Message-ID: <560BC6ED.3090205@samsung.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi, On 2015? 09? 28? 01:11, Charles Keepax wrote: > If binding failed calling exynos_dp_enable in exynos_dp_resume will > result in several NULL pointer dereferences. It is much better to > simply skip suspend/resume handling if bind has failed, do so by > checking if a drm_dev exists. Thanks for your patch. However, the pm interfaces of KMS drivers aren't required because these are controlled by top of Exynos drm driver and connector dpms. So I posted a patch that it removes pm interfaces of dp driver. Thanks, Inki Dae > > Signed-off-by: Charles Keepax > --- > drivers/gpu/drm/exynos/exynos_dp_core.c | 6 ++++++ > 1 files changed, 6 insertions(+), 0 deletions(-) > > diff --git a/drivers/gpu/drm/exynos/exynos_dp_core.c b/drivers/gpu/drm/exynos/exynos_dp_core.c > index d66ade0..48baf07 100644 > --- a/drivers/gpu/drm/exynos/exynos_dp_core.c > +++ b/drivers/gpu/drm/exynos/exynos_dp_core.c > @@ -1388,6 +1388,9 @@ static int exynos_dp_suspend(struct device *dev) > { > struct exynos_dp_device *dp = dev_get_drvdata(dev); > > + if (!dp->drm_dev) > + return 0; > + > exynos_dp_disable(&dp->encoder); > return 0; > } > @@ -1396,6 +1399,9 @@ static int exynos_dp_resume(struct device *dev) > { > struct exynos_dp_device *dp = dev_get_drvdata(dev); > > + if (!dp->drm_dev) > + return 0; > + > exynos_dp_enable(&dp->encoder); > return 0; > } >