Re: [XEN PATCH][for-4.19] domain: add ASSERT to help static analysis tools

[Nicola Vetrini <nicola.vetrini@xxxxxxxxxxx>]

On 2023-11-08 14:37, Andrew Cooper wrote:
> On 03/11/2023 5:58 pm, Nicola Vetrini wrote:
> > Static analysis tools may detect a possible null
> > pointer dereference at line 760 (the memcpy call)
> > of xen/common/domain.c. This ASSERT helps them in
> > detecting that such a condition is not possible
> > and also provides a basic sanity check.
> >
> > Signed-off-by: Nicola Vetrini <nicola.vetrini@xxxxxxxxxxx>
> > ---
> > The check may be later improved by proper error checking
> > instead of relying on the semantics explained here:
> > https://lore.kernel.org/xen-devel/61f04d4b-34d9-4fd1-a989-56b042b4f3d8@xxxxxxxxxx/
> >
> > This addresses the caution reported by ECLAIR for MISRA C:2012 D4.11
> > ---
> >  xen/common/domain.c | 2 ++
> >  1 file changed, 2 insertions(+)
> >
> > diff --git a/xen/common/domain.c b/xen/common/domain.c
> > index 8f9ab01c0cb7..9378c0417645 100644
> > --- a/xen/common/domain.c
> > +++ b/xen/common/domain.c
> > @@ -700,6 +700,8 @@ struct domain *domain_create(domid_t domid,
> >
> >      if ( !is_idle_domain(d) )
> >      {
> > +        ASSERT(config);
> > +
> >          watchdog_domain_init(d);
> >          init_status |= INIT_watchdog;
> I have an idea that might resolve this differently and in an easier 
> way.
> Would you be happy waiting for a couple of days for me to experiment? 
> Absolutely no guarantees of it turning into a workable solution.
Sure, no problem.

--
Nicola Vetrini, BSc
Software Engineer, BUGSENG srl (https://bugseng.com)