Re: [PATCH v3 1/1] kprobes: retry blocked optprobe in do_free_cleaned_kprobes

From: Google

Date: Tue Jan 20 2026 - 00:50:38 EST


On Thu, 15 Jan 2026 10:38:03 +0800
hongao <hongao@xxxxxxxxxxxxx> wrote:

> Once the aggrprobe is fully reverted in do_free_cleaned_kprobes(), retry
> optimize_kprobe() on that sibling so it can return to OPTIMIZED.
>
> Also remove the stale comment in __disarm_kprobe().
>

Thanks, let me pick it.

> Signed-off-by: hongao <hongao@xxxxxxxxxxxxx>
> ---
> kernel/kprobes.c | 18 ++++++++++++------
> 1 file changed, 12 insertions(+), 6 deletions(-)
>
> diff --git a/kernel/kprobes.c b/kernel/kprobes.c
> index ab8f9fc1f0d1..1bd84d3b4817 100644
> --- a/kernel/kprobes.c
> +++ b/kernel/kprobes.c
> @@ -516,6 +516,7 @@ static LIST_HEAD(freeing_list);
>
> static void kprobe_optimizer(struct work_struct *work);
> static DECLARE_DELAYED_WORK(optimizing_work, kprobe_optimizer);
> +static void optimize_kprobe(struct kprobe *p);
> #define OPTIMIZE_DELAY 5
>
> /*
> @@ -593,6 +594,17 @@ static void do_free_cleaned_kprobes(void)
> */
> continue;
> }
> +
> + /*
> + * The aggregator was holding back another probe while it sat on the
> + * unoptimizing/freeing lists. Now that the aggregator has been fully
> + * reverted we can safely retry the optimization of that sibling.
> + */
> +
> + struct kprobe *_p = get_optimized_kprobe(op->kp.addr);
> + if (unlikely(_p))
> + optimize_kprobe(_p);
> +
> free_aggr_kprobe(&op->kp);
> }
> }
> @@ -1002,12 +1014,6 @@ static void __disarm_kprobe(struct kprobe *p, bool reopt)
> if (unlikely(_p) && reopt)
> optimize_kprobe(_p);
> }
> - /*
> - * TODO: Since unoptimization and real disarming will be done by
> - * the worker thread, we can not check whether another probe are
> - * unoptimized because of this probe here. It should be re-optimized
> - * by the worker thread.
> - */
> }
>
> #else /* !CONFIG_OPTPROBES */
> --
> 2.50.1
>


--
Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>