Re: [linux-safety] [PATCH] usb: host: ehci-sched: add comment about find_tt() not returning error

From: Greg Kroah-Hartman
Date: Tue Oct 13 2020 - 01:21:58 EST


On Mon, Oct 12, 2020 at 08:17:34PM +0200, Lukas Bulwahn wrote:
> > If you are suggesting some sort of special code annotation that the tool
> > would understand, I am open to that. But I'm not aware of any even
> > vaguely standard way of marking up a particular function call to
> > indicate it will not return an error.
>
> I cannot yet say if some annotation would work, we, Sudip and me, need to
> investigate. It could be that something like, assert(!IS_ERR(tt)), is
> sufficient to let the tools know that they can safely assume that the
> path they are complaining about is not possible.
>
> We could make the assert() a nop, so it would not effect the resulting
> object code in any way.

Things like assert() have been rejected numberous times in the past in
the kernel, good luck with that :)

greg k-h