Subject: Re: [PATCH] rt2x00: reset reg earlier in rt2500usb_register_read

From: Greg KH <[email-masked]>
Date: Thu, 21 Jan 2021 12:21:24 +0100

On Thu, Jan 21, 2021 at 06:59:08PM +0800, 慕冬亮 wrote:
> > >       rt2x00usb_vendor_request_buff(rt2x00dev, USB_MULTI_READ,
> > >                                     USB_VENDOR_REQUEST_IN, offset,
> > >                                     &reg, sizeof(reg));
> >
> > Are you sure this is valid to call this function with a variable on the
> > stack like this?  How did you test this change?
> 
> First, I did not do any changes to this call. Second, the programming
> style to pass the pointer of stack variable as arguments is not really
> good. Third, I check this same code file, there are many code snippets
> with such programming style. :(

I know you did not change it, what I am asking is how did you test this
change works?  I think the kernel will warn you in huge ways that using
this pointer on the stack is incorrect, which implies you did not test
this change :(

thanks,

greg k-h