Re: [PATCH] drm/rockchip: vop: Don't crash for invalid duplicate_state()

From: Sean Paul <sean@poorly.run>
To: Brian Norris <briannorris@chromium.org>
Cc: "Daniel Vetter" <daniel@ffwll.ch>,
	"David Airlie" <airlied@linux.ie>,
	"Heiko Stübner" <heiko@sntech.de>,
	"Doug Anderson" <dianders@chromium.org>,
	dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org,
	linux-rockchip@lists.infradead.org,
	"Sandy Huang" <hjc@rock-chips.com>,
	"Sean Paul" <seanpaul@chromium.org>
Subject: Re: [PATCH] drm/rockchip: vop: Don't crash for invalid duplicate_state()
Date: Thu, 23 Jun 2022 16:46:56 +0000	[thread overview]
Message-ID: <YrSZAMYzEkXUExNG@art_vandelay> (raw)
In-Reply-To: <20220617172623.1.I62db228170b1559ada60b8d3e1637e1688424926@changeid>

On Fri, Jun 17, 2022 at 05:26:52PM -0700, Brian Norris wrote:
> 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.
> 
> Signed-off-by: Brian Norris <briannorris@chromium.org>

Thanks for this patch!

Reviewed-by: Sean Paul <seanpaul@chromium.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 74562d40f639..daf192881353 100644
> --- a/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
> +++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop.c
> @@ -1570,6 +1570,9 @@ 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;
> -- 
> 2.36.1.476.g0c4daa206d-goog
> 

-- 
Sean Paul, Software Engineer, Google / Chromium OS

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