Re: [PATCH 2/6] x86,perf/cqm: Fix cqm memory leak and notifier leak

[Vikas Shivappa]

On Wed, 2 Mar 2016, Thomas Gleixner wrote:

> On Tue, 1 Mar 2016, Vikas Shivappa wrote:
>
> > Fixes the hotcpu notifier leak and a memory leak during cqm(cache
> > quality of service monitoring) initialization.
> >
> > Reviewed-by: Tony Luck <tony.luck@xxxxxxxxx>
> > Signed-off-by: Vikas Shivappa <vikas.shivappa@xxxxxxxxxxxxxxx>
> > ---
> >  arch/x86/kernel/cpu/perf_event_intel_cqm.c | 17 ++++++++++++-----
> >  1 file changed, 12 insertions(+), 5 deletions(-)
> >
> > diff --git a/arch/x86/kernel/cpu/perf_event_intel_cqm.c b/arch/x86/kernel/cpu/perf_event_intel_cqm.c
> > index e6be335..5666171 100644
> > --- a/arch/x86/kernel/cpu/perf_event_intel_cqm.c
> > +++ b/arch/x86/kernel/cpu/perf_event_intel_cqm.c
> > @@ -1322,7 +1322,7 @@ static const struct x86_cpu_id intel_cqm_match[] = {
> >
> >  static int __init intel_cqm_init(void)
> >  {
> > -	char *str, scale[20];
> > +	char *str = NULL, scale[20];
> >  	int i, cpu, ret;
> >
> >  	if (!x86_match_cpu(intel_cqm_match))
> > @@ -1382,16 +1382,23 @@ static int __init intel_cqm_init(void)
> >  		cqm_pick_event_reader(i);
> >  	}
> >
> > -	__perf_cpu_notifier(intel_cqm_cpu_notifier);
> > -
> >  	ret = perf_pmu_register(&intel_cqm_pmu, "intel_cqm", -1);
> > -	if (ret)
> > +	if (ret) {
> >  		pr_err("Intel CQM perf registration failed: %d\n", ret);
> > -	else
> > +		goto out;
> > +	} else {
> >  		pr_info("Intel CQM monitoring enabled\n");
> > +	}
> >
> > +	/*
> > +	 * Register the hot cpu notifier once we are sure cqm
> > +	 * is enabled to avoid notifier leak.
> > +	 */
> > +	__perf_cpu_notifier(intel_cqm_cpu_notifier);
> >  out:
> >  	cpu_notifier_register_done();
> > +	if (ret)
> > +		kfree(str);
>
> This still leaks cqm_rmid_ptrs ....

Thats right. Thought there must be something more than the str leak i fixed, 
but missed this. Will fix

Thanks,
Vikas