Re: [PATCH v2 1/3] rust: core abstractions for network PHY drivers

Greg KH
2023-10-07T11:30:57Z

On Sat, Oct 07, 2023 at 08:23:24PM +0900, FUJITA Tomonori wrote:
> On Sat, 7 Oct 2023 13:17:13 +0200
> Greg KH <gregkh@linuxfoundation.org> wrote:
>
> > On Sat, Oct 07, 2023 at 07:58:57PM +0900, FUJITA Tomonori wrote:
> >> > Since we're taking user input, it probably doesn't hurt to do some
> >> > sort of sanity check rather than casting. Maybe warn once then return
> >> > the biggest nowrapping value
> >> >
> >> > let speed_i32 = i32::try_from(speed).unwrap_or_else(|_| {
> >> > warn_once!("excessive speed {speed}");
> >
> > NEVER call WARN() on user input, as you now just rebooted the machine
> > and caused a DoS (and syzbot will start to spam you with reports.)
>
> Trevor uses `user` as the user of this function, which is a PHY driver.
>

Ok, same thing in a way, just do a dev_warn() and return an error, no
need to do a full traceback splat at all.

thanks,

greg k-h