Re: [PATCH 8/8] xen/hvc: replace BUG_ON() with negative return value

[Juergen Gross <jgross@xxxxxxxx>]

On 13.05.21 12:16, Christophe Leroy wrote:
> Le 13/05/2021 à 12:03, Juergen Gross a écrit :
> > Xen frontends shouldn't BUG() in case of illegal data received from
> > their backends. So replace the BUG_ON()s when reading illegal data from
> > the ring page with negative return values.
> >
> > Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
> > ---
> >   drivers/tty/hvc/hvc_xen.c | 15 +++++++++++++--
> >   1 file changed, 13 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c
> > index 92c9a476defc..30d7ffb1e04c 100644
> > --- a/drivers/tty/hvc/hvc_xen.c
> > +++ b/drivers/tty/hvc/hvc_xen.c
> > @@ -86,6 +86,11 @@ static int __write_console(struct xencons_info 
> > *xencons,
> >       cons = intf->out_cons;
> >       prod = intf->out_prod;
> >       mb();            /* update queue values before going on */
> > +
> > +    if (WARN_ONCE((prod - cons) > sizeof(intf->out),
> > +              "Illegal ring page indices"))
> > +        return -EINVAL;
> > +
> >       BUG_ON((prod - cons) > sizeof(intf->out));
> Why keep the BUG_ON() ?
Oh, failed to delete it. Thanks for noticing.


Juergen

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