Re: [PATCH] hw breakpoint: Fix possible memory leak

Namhyung Kim
2012-02-27T12:45:52Z

2012-02-27 (Mon), 12:04 +0100, Peter Zijlstra wrote:
> On Mon, 2012-02-27 at 11:44 +0100, Ingo Molnar wrote:
> > I edited that code earlier today - is the form below OK, or can
> > you see a simpler method? It's not yet pushed out so can still
> > edit it.
>
> I think something like the below should do, but then I didn't really
> think much about it, my thoughts went like:
>
> ... *shees* that's ugly
> ... that error path already does a loop
> ... what the problem is!? -- reread changelog
> ... err_cpu == cpu is placed wrong!
>
>
> So I replied and marked read.. waiting to either hear if there's a good
> reason to do ugly or find a new (tested) patch in my inbox.. :-)
>
> ---
> kernel/events/hw_breakpoint.c | 4 ++--
> 1 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/events/hw_breakpoint.c b/kernel/events/hw_breakpoint.c
> index b0309f7..3330022 100644
> --- a/kernel/events/hw_breakpoint.c
> +++ b/kernel/events/hw_breakpoint.c
> @@ -658,10 +658,10 @@ int __init init_hw_breakpoint(void)
>
> err_alloc:
> for_each_possible_cpu(err_cpu) {
> - if (err_cpu == cpu)
> - break;
> for (i = 0; i < TYPE_MAX; i++)
> kfree(per_cpu(nr_task_bp_pinned[i], cpu));
> + if (err_cpu == cpu)
> + break;
> }
>
> return -ENOMEM;
>

This would depend on the initial value of the percpu memory, and thus
have no problem in this case. It looks better to me, too :)

--
Regards,
Namhyung Kim