Re: [PATCH v2 06/16] watchdog: hpwdt: drop warning after calling watchdog_init_timeout

[Guenter Roeck]

On 4/24/19 1:38 AM, Geert Uytterhoeven wrote:
> Hi Wolfram,
>
> On Wed, Apr 17, 2019 at 9:46 PM Wolfram Sang <wsa@xxxxxxxxxxxxx> wrote:
> > > Yes, that works as well. Note that it will actually print something like
> > > "watchdog: <device>: ..." due to the pr_fmt() at the top of watchdog_core.c.
> > > I guess that should be ok.
> >
> > I have the following diff applied on top of patch 2. Works with and
> > without a parent device. I am not super happy casting 'identity' but
> > since its u8-type is exported to userspace, I think we can't avoid it.
> > Guenter, is this cast safe? Here is the diff:
> >
> > diff --git a/drivers/watchdog/watchdog_core.c b/drivers/watchdog/watchdog_core.c
> > index cd3ca6b366ef..62be9e52a4de 100644
> > --- a/drivers/watchdog/watchdog_core.c
> > +++ b/drivers/watchdog/watchdog_core.c
> > @@ -115,6 +115,8 @@ static void watchdog_check_min_max_timeout(struct watchdog_device *wdd)
> >   int watchdog_init_timeout(struct watchdog_device *wdd,
> >                                  unsigned int timeout_parm, struct device *dev)
> >   {
> > +       const char *dev_str = wdd->parent ? dev_name(wdd->parent) :
> > +                             (const char *)wdd->info->identity;
>
>      struct watchdog_info {
>              ...
>              __u8  identity[32];     /* Identity of the board */
>      };
>
> Is identity[] guaranteed to be NUL-terminated?

I would hope so, because we export its contents via sysfs to userspace
with
	return sprintf(buf, "%s\n", wdd->info->identity);

Also, there are already several pr_err() assuming that it is
a string,

Guenter