From 0fa375e6bc9023211eead30a6a79963c45a563da Mon Sep 17 00:00:00 2001 From: Jeffy Chen Date: Wed, 9 Aug 2017 18:41:03 +0800 Subject: drm/rockchip: Fix suspend crash when drm is not bound 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 Signed-off-by: Sean Paul Link: https://patchwork.kernel.org/patch/9890297/ --- drivers/gpu/drm/rockchip/rockchip_drm_drv.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) (limited to 'drivers/gpu/drm/rockchip') diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_drv.c b/drivers/gpu/drm/rockchip/rockchip_drm_drv.c index c6b1b7f3a2a3..c16bc0a7115b 100644 --- a/drivers/gpu/drm/rockchip/rockchip_drm_drv.c +++ b/drivers/gpu/drm/rockchip/rockchip_drm_drv.c @@ -275,11 +275,15 @@ 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); @@ -293,8 +297,12 @@ 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); -- cgit v1.2.3-55-g7522