Re: Fwd: [bug report] drm/msm/dsi: Split PHY drivers to separate files

[jesszhan@codeaurora.org]

Hey Dan,

On 2021-10-04 16:28, abhinavk@codeaurora.org wrote:
> -------- Original Message --------
> Subject: [bug report] drm/msm/dsi: Split PHY drivers to separate files
> Date: 2021-10-04 03:37
> From: Dan Carpenter <dan.carpenter@oracle.com>
> To: hali@codeaurora.org
> Cc: linux-arm-msm@vger.kernel.org
> 
> Hello Hai Li,
> 
> This is a semi-automatic email about new static checker warnings.
> 
> The patch 5c8290284402: "drm/msm/dsi: Split PHY drivers to separate
> files" from Aug 13, 2015, leads to the following Smatch complaint:
> 
>     drivers/gpu/drm/msm/dsi/phy/dsi_phy.c:812 msm_dsi_phy_enable()
>     warn: variable dereferenced before check 'phy' (see line 809)
> 
> drivers/gpu/drm/msm/dsi/phy/dsi_phy.c
>    805  int msm_dsi_phy_enable(struct msm_dsi_phy *phy,
>    806                          struct msm_dsi_phy_clk_request 
> *clk_req,
>    807                          struct msm_dsi_phy_shared_timings
> *shared_timings)
>    808	{
>    809		struct device *dev = &phy->pdev->dev;
>                                       ^^^^^^^^^^^^^^
> "phy" is deferenced without checking
> 
>    810		int ret;
>    811
>    812		if (!phy || !phy->cfg->ops.enable)
>                      ^^^
> Too late.  The fact that no one has complained in six years suggests
> that the NULL check can be removed but it wasn't 100% to obvious from
> reading the code.
> 
>    813			return -EINVAL;
>    814
> 
> regards,
> dan carpenter

Thanks for the report, will look into it.

Best,
Jessica Zhang