Re: [PATCH V6 XRT Alveo 08/20] fpga: xrt: driver infrastructure

From: Lizhi Hou
Date: Wed May 19 2021 - 22:48:23 EST




On 05/13/2021 08:27 AM, Tom Rix wrote:

On 5/11/21 6:53 PM, Lizhi Hou wrote:
Infrastructure code providing APIs for managing leaf driver instance
groups, facilitating inter-leaf driver calls and root calls.

Signed-off-by: Sonal Santan <sonal.santan@xxxxxxxxxx>
Signed-off-by: Max Zhen <max.zhen@xxxxxxxxxx>
Signed-off-by: Lizhi Hou <lizhi.hou@xxxxxxxxxx>
Reviewed-by: Tom Rix <trix@xxxxxxxxxx>

+
+int xrt_subdev_root_request(struct xrt_device *self, u32 cmd, void *arg)
+{
+ struct device *dev = DEV(self);
+ struct xrt_subdev_platdata *pdata = DEV_PDATA(self);
+
+ WARN_ON(!pdata->xsp_root_cb);
+ return (*pdata->xsp_root_cb)(dev->parent, pdata->xsp_root_cb_arg, cmd, arg);

I am running v6 through clang's static analyzer.

It reports this problem

drivers/fpga/xrt/lib/subdev.c:72:9: warning: Called function pointer is
null (null dereference)
return (*pdata->xsp_root_cb)(dev->parent,
pdata->xsp_root_cb_arg, cmd, arg);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Though there is a warn_on, can you also add a

return -EINVAL;

To cover this case?
Sure. I will run through clang myself to check the fix.

Thanks,
Lizhi

Tom

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