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Date:   Wed, 24 Apr 2019 15:20:20 +0200
From:   Daniel Vetter <daniel@ffwll.ch>
To:     Tomeu Vizoso <tomeu.vizoso@collabora.com>
Cc:     linux-kernel@vger.kernel.org, Rob Herring <robh@kernel.org>,
        David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        dri-devel@lists.freedesktop.org
Subject: Re: [PATCH] drm/panfrost: Add sanity checks to submit IOCTL
Message-ID: <20190424132019.GS9857@phenom.ffwll.local>
Mail-Followup-To: Tomeu Vizoso <tomeu.vizoso@collabora.com>,
        linux-kernel@vger.kernel.org, Rob Herring <robh@kernel.org>,
        David Airlie <airlied@linux.ie>, dri-devel@lists.freedesktop.org
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On Wed, Apr 24, 2019 at 03:13:53PM +0200, Tomeu Vizoso wrote:
> So userspace can get feedback on any error conditions, instead of going
> ahead and things breaking later.
> 
> Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>

Bonus: some igts to exercise these corner cases. It helps a lot with uapi
review and testing.
-Daniel

> ---
>  drivers/gpu/drm/panfrost/panfrost_drv.c | 35 +++++++++++++++++--------
>  1 file changed, 24 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c b/drivers/gpu/drm/panfrost/panfrost_drv.c
> index c06af78ab833..0f2863cb8077 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_drv.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_drv.c
> @@ -172,13 +172,27 @@ static int panfrost_ioctl_submit(struct drm_device *dev, void *data,
>  {
>  	struct panfrost_device *pfdev = dev->dev_private;
>  	struct drm_panfrost_submit *args = data;
> -	struct drm_syncobj *sync_out;
> +	struct drm_syncobj *sync_out = NULL;
>  	struct panfrost_job *job;
>  	int ret = 0;
>  
> +	if (!args->jc)
> +		return -EINVAL;
> +
> +	if (args->requirements && args->requirements != PANFROST_JD_REQ_FS)
> +		return -EINVAL;
> +
> +	if (args->out_sync > 0) {
> +		sync_out = drm_syncobj_find(file, args->out_sync);
> +		if (!sync_out)
> +			return -ENODEV;
> +	}
> +
>  	job = kzalloc(sizeof(*job), GFP_KERNEL);
> -	if (!job)
> -		return -ENOMEM;
> +	if (!job) {
> +		ret = -ENOMEM;
> +		goto fail_out_sync;
> +	}
>  
>  	kref_init(&job->refcount);
>  
> @@ -190,25 +204,24 @@ static int panfrost_ioctl_submit(struct drm_device *dev, void *data,
>  
>  	ret = panfrost_copy_in_sync(dev, file, args, job);
>  	if (ret)
> -		goto fail;
> +		goto fail_job;
>  
>  	ret = panfrost_lookup_bos(dev, file, args, job);
>  	if (ret)
> -		goto fail;
> +		goto fail_job;
>  
>  	ret = panfrost_job_push(job);
>  	if (ret)
> -		goto fail;
> +		goto fail_job;
>  
>  	/* Update the return sync object for the job */
> -	sync_out = drm_syncobj_find(file, args->out_sync);
> -	if (sync_out) {
> +	if (sync_out)
>  		drm_syncobj_replace_fence(sync_out, job->render_done_fence);
> -		drm_syncobj_put(sync_out);
> -	}
>  
> -fail:
> +fail_job:
>  	panfrost_job_put(job);
> +fail_out_sync:
> +	drm_syncobj_put(sync_out);
>  
>  	return ret;
>  }
> -- 
> 2.20.1
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch