Re: linux-next: build warning after merge of the drivers-x86 tree

[Darren Hart]

On Thu, Dec 15, 2016 at 11:02:19AM +1100, Stephen Rothwell wrote:
> Hi Darren,
> 
> On Wed, 14 Dec 2016 14:59:14 -0800 Darren Hart <dvhart@xxxxxxxxxxxxx> wrote:
> >
> > On Wed, Dec 14, 2016 at 02:21:38PM -0800, Darren Hart wrote:
> > > On Wed, Dec 14, 2016 at 01:50:44PM +1100, Stephen Rothwell wrote:  
> > > > 
> > > > After merging the drivers-x86 tree, today's linux-next build (x86_64
> > > > allmodconfig) produced this warning:
> > > > 
> > > > In file included from include/linux/kernel.h:13:0,
> > > >                  from drivers/platform/x86/thinkpad_acpi.c:52:
> > > > drivers/platform/x86/thinkpad_acpi.c: In function 'hotkey_init':
> > > > include/linux/printk.h:299:2: warning: 'type' may be used uninitialized in this function [-Wmaybe-uninitialized]
> > > >   printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
> > > >   ^
> > > > drivers/platform/x86/thinkpad_acpi.c:3147:8: note: 'type' was declared here
> > > >   char *type;
> > > >         ^
> > > > In file included from include/linux/kernel.h:13:0,
> > > >                  from drivers/platform/x86/thinkpad_acpi.c:52:
> > > > include/linux/printk.h:299:2: warning: 'in_tablet_mode' may be used uninitialized in this function [-Wmaybe-uninitialized]
> > > >   printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
> > > >   ^
> > > > drivers/platform/x86/thinkpad_acpi.c:3146:6: note: 'in_tablet_mode' was declared here
> > > >   int in_tablet_mode, res;
> > > >       ^
> > > > 
> > > > Introduced by commit
> > > > 
> > > >   b31800283868 ("platform/x86: thinkpad_acpi: Move tablet detection into separate function")
> > > > 
> > > > I can't tell if this is a false positive or not.  
> > > 
> > > That's an uninitialized local variable. Not sure how I missed that. I'll
> > > fix it up today. Thank you for the report.  
> > 
> > OK, no, it's a false positive because tp_features.hotkey_tablet is assigned in
> > both places where in_tablet_mode is assigned, and if the former is 0 (global
> > scope), the function returns without calling pr_info.
> 
> How about "type".

Ooops, indeed. Same exact issue. I'll update the patch.

-- 
Darren Hart
Intel Open Source Technology Center