On 04/10/2021 13:37, Dan Carpenter wrote:
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.
Yes, phy can not be NULL, since otherwise dsi_get_phy would make
dsi_init return -EPROBE_DEFER.
813 return -EINVAL;
814
regards,
dan carpenter
--
With best wishes
Dmitry
