Re: [PATCH] drivers/base/node: Handle error properly in register_one_node()

[Donet Tom]

On 7/4/25 5:59 PM, David Hildenbrand wrote:
> On 02.07.25 14:59, Donet Tom wrote:
> > On 7/2/25 6:16 PM, Oscar Salvador wrote:
> > > On Wed, Jul 02, 2025 at 06:28:56AM -0500, Donet Tom wrote:
> > > > If register_node() returns an error, it is not handled correctly.
> > > > The function will proceed further and try to register CPUs under the
> > > > node, which is not correct.
> > > >
> > > > So, in this patch, if register_node() returns an error, we return
> > > > immediately from the function.
> > > >
> > > > Signed-off-by: Donet Tom <donettom@xxxxxxxxxxxxx>
> > > > ---
> > > ...
> > > > diff --git a/drivers/base/node.c b/drivers/base/node.c
> > > > index bef84f01712f..aec991b4c0b2 100644
> > > > --- a/drivers/base/node.c
> > > > +++ b/drivers/base/node.c
> > > > @@ -885,6 +885,8 @@ int register_one_node(int nid)
> > > >        node_devices[nid] = node;
> > > >           error = register_node(node_devices[nid], nid);
> > > > +    if (error)
> > > > +        return error;
> > > Ok, all current callers (based on mm-unstable) panic or BUG() if 
> > > this fails,
> > > but powerpc, in init_phb_dynamic(), which keeps on going.
> > > Unless it panics somewhere down the road as well.
> > >
> > > So I think we need to:
> > >
> > >    node_devices[nid] = NULL
> > >    kfree(node)
> > >
> > >    ?
> >
> >
> > Yes, I will add this too.
> >
> > But one question: if register_node() fails, is it okay to continue, or
> > should we panic?
> >
> > What is the correct way to handle this?
>
> panic() or BUG() is not the answer :)
>
> Try to recover ...

Got it, thank you very much, David.