Message-ID: <3025b62f-fbaa-cda3-8ab4-73e86b942450@linaro.org>
Date:   Tue, 21 Mar 2023 17:17:26 +0200
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Subject: Re: [PATCH 04/10] drm/msm: fix NULL-deref on irq uninstall
Content-Language: en-GB
To:     Johan Hovold <johan+linaro@kernel.org>,
        Rob Clark <robdclark@gmail.com>,
        Abhinav Kumar <quic_abhinavk@quicinc.com>
Cc:     Sean Paul <sean@poorly.run>, David Airlie <airlied@gmail.com>,
        Daniel Vetter <daniel@ffwll.ch>, linux-arm-msm@vger.kernel.org,
        dri-devel@lists.freedesktop.org, freedreno@lists.freedesktop.org,
        linux-kernel@vger.kernel.org, stable@vger.kernel.org,
        Thomas Zimmermann <tzimmermann@suse.de>
References: <20230306100722.28485-1-johan+linaro@kernel.org>
 <20230306100722.28485-5-johan+linaro@kernel.org>
From:   Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
In-Reply-To: <20230306100722.28485-5-johan+linaro@kernel.org>
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Precedence: bulk

On 06/03/2023 12:07, Johan Hovold wrote:
> In case of early initialisation errors and on platforms that do not use
> the DPU controller, the deinitilisation code can be called with the kms
> pointer set to NULL.
> 
> Fixes: f026e431cf86 ("drm/msm: Convert to Linux IRQ interfaces")
> Cc: stable@vger.kernel.org	# 5.14
> Cc: Thomas Zimmermann <tzimmermann@suse.de>
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

> ---
>   drivers/gpu/drm/msm/msm_drv.c | 8 +++++---
>   1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
> index 17a59d73fe01..2f2bcdb671d2 100644
> --- a/drivers/gpu/drm/msm/msm_drv.c
> +++ b/drivers/gpu/drm/msm/msm_drv.c
> @@ -251,9 +251,11 @@ static int msm_drm_uninit(struct device *dev)
>   		drm_bridge_remove(priv->bridges[i]);
>   	priv->num_bridges = 0;
>   
> -	pm_runtime_get_sync(dev);
> -	msm_irq_uninstall(ddev);
> -	pm_runtime_put_sync(dev);
> +	if (kms) {
> +		pm_runtime_get_sync(dev);
> +		msm_irq_uninstall(ddev);
> +		pm_runtime_put_sync(dev);
> +	}
>   
>   	if (kms && kms->funcs)
>   		kms->funcs->destroy(kms);

-- 
With best wishes
Dmitry