On Tue, Oct 11, 2022 at 03:11:28PM +0800, Hou Tao wrote:
> From: Hou Tao <houtao1@xxxxxxxxxx>
>
> To support sleepable uprobe bpf program, the freeing of trace program
> array chains a RCU-tasks-trace grace period with a normal RCU grace
> period. But considering in the current implementation of RCU-tasks-trace
> that one RCU-tasks-trace grace period implies one normal RCU grace
> period, so it is not need for such chaining and it is safe to free the
> array in the callback of call_rcu_tasks_trace().
And the same here. ;-)
Thanx, Paul
> Signed-off-by: Hou Tao <houtao1@xxxxxxxxxx>
> ---
> kernel/bpf/core.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
> index 711fd293b6de..f943620b55b0 100644
> --- a/kernel/bpf/core.c
> +++ b/kernel/bpf/core.c
> @@ -2247,12 +2247,15 @@ void bpf_prog_array_free(struct bpf_prog_array *progs)
> kfree_rcu(progs, rcu);
> }
>
> +/* Now RCU Tasks grace period implies RCU grace period, so no need to call
> + * kfree_rcu(), just call kfree() directly.
> + */
> static void __bpf_prog_array_free_sleepable_cb(struct rcu_head *rcu)
> {
> struct bpf_prog_array *progs;
>
> progs = container_of(rcu, struct bpf_prog_array, rcu);
> - kfree_rcu(progs, rcu);
> + kfree(progs);
> }
>
> void bpf_prog_array_free_sleepable(struct bpf_prog_array *progs)
> --
> 2.29.2
>
