Re: [PATCH 78/89] sched/core: Remove the tsk_cpus_allowed() wrapper

Peter Zijlstra
2017-02-07T08:06:57Z

On Mon, Feb 06, 2017 at 11:03:08PM +0100, Ingo Molnar wrote:
>
> * Peter Zijlstra <peterz@infradead.org> wrote:
>
> > > +++ b/arch/powerpc/kernel/smp.c
> > > +++ b/arch/sparc/kernel/sysfs.c
> > > +++ b/drivers/cpufreq/sparc-us2e-cpufreq.c
> > > +++ b/drivers/cpufreq/sparc-us3-cpufreq.c
>
> > > - cpumask_copy(&cpus_allowed, tsk_cpus_allowed(current));
> > > + cpumask_copy(&cpus_allowed, &current->cpus_allowed);
> >
> > Note that all those, and this is where I stopped looking, appear broken vs
> > userspace changing the mask right after.
>
> But these are pre-existing bugs in code twidding ->cpus_allowed, not caused by my
> patch, right?

Yes..

> I.e. my changes made you notice pre-existing bugs.

I think I spotted them when I made the tsk_cpus_allowed() thing as well.
Just wanted to call them out again.