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

From: Lukas Bulwahn
Date: Tue Oct 13 2020 - 01:41:52 EST




On Tue, 13 Oct 2020, Greg Kroah-Hartman wrote:

> 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, we have been warned by you now; so, we are well aware what could
await us just as numerous others before.

Lukas