On Tue, Feb 02, 2021 at 10:05:39PM +0300, Dan Carpenter wrote:
> On Tue, Feb 02, 2021 at 07:53:17PM +0100, Pavel Machek wrote:
> > Hi!
> >
> > > From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> > >
> > > [ Upstream commit b552766c872f5b0d90323b24e4c9e8fa67486dd5 ]
> > >
> > > The "bec" struct isn't necessarily always initialized. For example, the
> > > mcp251xfd_get_berr_counter() function doesn't initialize anything if the
> > > interface is down.
> >
> > Well, yes... and = {} does not neccessarily initialize all of the
> > structure... for example padding.
> >
> > It is really simple
> >
> > struct can_berr_counter {
> > __u16 txerr;
> > __u16 rxerr;
> > };
> >
> > but maybe something like alpha uses padding in such case, and memset
> > would be better?
>
> I'm pretty sure nothing uses padding in this situation. If it does then
> we need to re-work a bunch of code.
Not necessarily related but in theory a "= {};" assignment is a GCC
extension and it is supposed to zero out struct holes. If the code
does "= {0};" then that's standard C, and will not necessarily fill
struct holes but I think GCC tries to. The other complication is that
some GCC versions have bugs related to this? We had a long thread about
this last August.
https://lore.kernel.org/lkml/20200801144030.GM24045@xxxxxxxx/
Anyway, this code has no holes so it's not affected.
regards,
dan carpenter
