Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752047AbdHIKlU (ORCPT ); Wed, 9 Aug 2017 06:41:20 -0400 Received: from regular1.263xmail.com ([211.150.99.141]:33270 "EHLO regular1.263xmail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751722AbdHIKlT (ORCPT ); Wed, 9 Aug 2017 06:41:19 -0400 X-263anti-spam: KSV:0; X-MAIL-GRAY: 0 X-MAIL-DELIVERY: 1 X-KSVirus-check: 0 X-ABS-CHECKED: 4 X-RL-SENDER: jeffy.chen@rock-chips.com X-FST-TO: linux-kernel@vger.kernel.org X-SENDER-IP: 103.29.142.67 X-LOGIN-NAME: jeffy.chen@rock-chips.com X-UNIQUE-TAG: X-ATTACHMENT-NUM: 0 X-DNS-TYPE: 0 From: Jeffy Chen To: linux-kernel@vger.kernel.org, seanpaul@chromium.org, mark.yao@rock-chips.com Cc: briannorris@chromium.org, dianders@chromium.org, Jeffy Chen Subject: [PATCH] drm/rockchip: Fix suspend crash when drm is not bound Date: Wed, 9 Aug 2017 18:41:03 +0800 Message-Id: <1502275263-7081-1-git-send-email-jeffy.chen@rock-chips.com> X-Mailer: git-send-email 2.1.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2304 Lines: 62 Currently we are allocating drm_device in rockchip_drm_bind, so if the suspend/resume code access it when drm is not bound, we would hit this crash: [ 253.402836] Unable to handle kernel NULL pointer dereference at virtual address 00000028 [ 253.402837] pgd = ffffffc06c9b0000 [ 253.402841] [00000028] *pgd=0000000000000000, *pud=0000000000000000 [ 253.402844] Internal error: Oops: 96000005 [#1] PREEMPT SMP [ 253.402859] Modules linked in: btusb btrtl btbcm btintel bluetooth ath10k_pci ath10k_core ar10k_ath ar10k_mac80211 cfg80211 ip6table_filter asix usbnet mii [ 253.402864] CPU: 4 PID: 1331 Comm: cat Not tainted 4.4.70 #15 [ 253.402865] Hardware name: Google Scarlet (DT) [ 253.402867] task: ffffffc076c0ce00 ti: ffffffc06c2c8000 task.ti: ffffffc06c2c8000 [ 253.402871] PC is at rockchip_drm_sys_suspend+0x20/0x5c Add sanity checks to prevent that. Reported-by: Brian Norris Signed-off-by: Jeffy Chen --- drivers/gpu/drm/rockchip/rockchip_drm_drv.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_drv.c b/drivers/gpu/drm/rockchip/rockchip_drm_drv.c index c41f48a..ff3d0f5 100644 --- a/drivers/gpu/drm/rockchip/rockchip_drm_drv.c +++ b/drivers/gpu/drm/rockchip/rockchip_drm_drv.c @@ -270,11 +270,15 @@ static void rockchip_drm_fb_resume(struct drm_device *drm) static int rockchip_drm_sys_suspend(struct device *dev) { struct drm_device *drm = dev_get_drvdata(dev); - struct rockchip_drm_private *priv = drm->dev_private; + struct rockchip_drm_private *priv; + + if (!drm) + return 0; drm_kms_helper_poll_disable(drm); rockchip_drm_fb_suspend(drm); + priv = drm->dev_private; priv->state = drm_atomic_helper_suspend(drm); if (IS_ERR(priv->state)) { rockchip_drm_fb_resume(drm); @@ -288,8 +292,12 @@ static int rockchip_drm_sys_suspend(struct device *dev) static int rockchip_drm_sys_resume(struct device *dev) { struct drm_device *drm = dev_get_drvdata(dev); - struct rockchip_drm_private *priv = drm->dev_private; + struct rockchip_drm_private *priv; + + if (!drm) + return 0; + priv = drm->dev_private; drm_atomic_helper_resume(drm, priv->state); rockchip_drm_fb_resume(drm); drm_kms_helper_poll_enable(drm); -- 2.1.4