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

From: Paul E. McKenney
Date: Mon Jan 06 2020 - 16:43:35 EST


On Mon, Jan 06, 2020 at 01:08:37PM -0800, Olof Johansson wrote:
> On Mon, Jan 6, 2020 at 10:10 AM Paul E. McKenney <paulmck@xxxxxxxxxx> wrote:
> >
> > On Mon, Jan 06, 2020 at 09:51:47AM -0800, Olof Johansson wrote:
> > > Hi,
> > >
> > > On Wed, Dec 11, 2019 at 9:06 PM Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> wrote:
> > > >
> > > > Hi all,
> > > >
> > > > After merging the rcu (I think) tree, today's linux-next build (x86_64
> > > > allnoconfig) produced this warning:
> > > >
> > > > kernel/time/timer.c: In function 'schedule_timeout':
> > > > kernel/time/timer.c:969:20: warning: 'timer.expires' may be used uninitialized in this function [-Wmaybe-uninitialized]
> > > > 969 | long diff = timer->expires - expires;
> > > > | ~~~~~^~~~~~~~~
> > > >
> > > > Introduced by (bisected to) commit
> > > >
> > > > c4127fce1d02 ("timer: Use hlist_unhashed_lockless() in timer_pending()")
> > > >
> > > > x86_64-linux-gnu-gcc (Debian 9.2.1-21) 9.2.1 20191130
> > >
> > > This is still there as of last night's -next. Any update on getting a
> > > fix queued together with the offending patch?
> >
> > Hello, Olof,
> >
> > Thank you, I had indeed lost track of this one. :-/
> >
> > Does Eric's patch fix things for you?
> >
> > https://lore.kernel.org/lkml/CANn89i+xomdo4HFqewrfNf_Z4Q5ayXuW6A4SjSkE46JXP9KuFw@xxxxxxxxxxxxxx/
>
> It does, but it's not a proper patch (whitespace damage, no S-o-b, etc).

Understood, and thank you for checking!

Eric, would you be willing to turn this into a something that can be
sent upstream?

Thanx, Paul