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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Brian Norris <briannorris@chromium.org>,
        Sean Paul <seanpaul@chromium.org>,
        Douglas Anderson <dianders@chromium.org>,
        Heiko Stuebner <heiko@sntech.de>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.19 079/287] drm/rockchip: vop: Dont crash for invalid duplicate_state()
Date:   Tue, 23 Aug 2022 10:24:08 +0200
Message-Id: <20220823080102.922291150@linuxfoundation.org>
In-Reply-To: <20220823080100.268827165@linuxfoundation.org>
References: <20220823080100.268827165@linuxfoundation.org>
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From: Brian Norris <briannorris@chromium.org>

[ Upstream commit 1449110b0dade8b638d2c17ab7c5b0ff696bfccb ]

It's possible for users to try to duplicate the CRTC state even when the
state doesn't exist. drm_atomic_helper_crtc_duplicate_state() (and other
users of __drm_atomic_helper_crtc_duplicate_state()) already guard this
with a WARN_ON() instead of crashing, so let's do that here too.

Fixes: 4e257d9eee23 ("drm/rockchip: get rid of rockchip_drm_crtc_mode_config")
Signed-off-by: Brian Norris <briannorris@chromium.org>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20220617172623.1.I62db228170b1559ada60b8d3e1637e1688424926@changeid
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/rockchip/rockchip_drm_vop.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
index c0b647435974..69eb0de9973f 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
@@ -1088,6 +1088,9 @@ static struct drm_crtc_state *vop_crtc_duplicate_state(struct drm_crtc *crtc)
 {
 	struct rockchip_crtc_state *rockchip_state;
 
+	if (WARN_ON(!crtc->state))
+		return NULL;
+
 	rockchip_state = kzalloc(sizeof(*rockchip_state), GFP_KERNEL);
 	if (!rockchip_state)
 		return NULL;
-- 
2.35.1