Re: [PATCH v2] platform/x86: thinkpad_acpi: Initialize local in_tablet_mode and type

From: Darren Hart
Date: Thu Dec 15 2016 - 16:17:40 EST


On Thu, Dec 15, 2016 at 08:15:02PM +0200, Andy Shevchenko wrote:
> On Wed, 2016-12-14 at 20:14 -0800, Darren Hart wrote:
> > linux-next reported in_tablet_mode and type may be used uninitialized
> > after:
> >
> > b31800283868 ("platform/x86: thinkpad_acpi: Move tablet detection into
> > separate function")
> >
> > This turns out to be a false positive as the pr_info call cannot be
> > reached if tp_features.hotkey_tablet (global scope) is 0, and
> > in_tablet_mode and type are assigned in both places
> > tp_features.hotkey_tablet is assigned.
> >
> > Regardless, to make it explicit and avoid further reports, initialize
> > in_tablet_mode to 0 and type to "".
> >
>
> @@ -3143,8 +3143,8 @@ typedef tpacpi_keymap_entry_t
> > tpacpi_keymap_t[TPACPI_HOTKEY_MAP_LEN];
> >  
> >  static int hotkey_init_tablet_mode(void)
> >  {
> > - int in_tablet_mode, res;
> > - char *type;
> > + int in_tablet_mode = 0, res;
> > + char *type = "";
>
> Subtle correction
> NULL will work either and takes less memory ;)
>
> P.S. Even pr_*() is NULL-aware

Agreed. Fixed, pushed, tagged. Thanks all.

--
Darren Hart
Intel Open Source Technology Center