Hi Juntong,
On Wed, Feb 05, 2025 at 07:30:14PM +0000, Juntong Deng wrote:
> This patch adds filter for scx_kfunc_ids_select_cpu.
>
> The kfuncs in the scx_kfunc_ids_select_cpu set can be used in select_cpu
> and other rq-locked operations.
The only function in scx_kfunc_ids_select_cpu is scx_bpf_select_cpu_dfl(),
which should be called exclusively from ops.select_cpu() and not from any
rq-locked ops.
>
> Signed-off-by: Juntong Deng <juntong.deng@xxxxxxxxxxx>
> ---
> kernel/sched/ext.c | 42 ++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 42 insertions(+)
>
> diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c
> index 8857c0709bdd..c92949aa23f6 100644
> --- a/kernel/sched/ext.c
> +++ b/kernel/sched/ext.c
> @@ -6401,9 +6401,51 @@ BTF_KFUNCS_START(scx_kfunc_ids_select_cpu)
> BTF_ID_FLAGS(func, scx_bpf_select_cpu_dfl, KF_RCU)
> BTF_KFUNCS_END(scx_kfunc_ids_select_cpu)
>
> +static int scx_kfunc_ids_other_rqlocked_filter(const struct bpf_prog *prog, u32 kfunc_id)
> +{
> + u32 moff = prog->aux->attach_st_ops_member_off;
> +
> + if (moff == offsetof(struct sched_ext_ops, runnable) ||
> + moff == offsetof(struct sched_ext_ops, dequeue) ||
> + moff == offsetof(struct sched_ext_ops, stopping) ||
> + moff == offsetof(struct sched_ext_ops, quiescent) ||
> + moff == offsetof(struct sched_ext_ops, yield) ||
> + moff == offsetof(struct sched_ext_ops, cpu_acquire) ||
> + moff == offsetof(struct sched_ext_ops, running) ||
> + moff == offsetof(struct sched_ext_ops, core_sched_before) ||
> + moff == offsetof(struct sched_ext_ops, set_cpumask) ||
> + moff == offsetof(struct sched_ext_ops, update_idle) ||
> + moff == offsetof(struct sched_ext_ops, tick) ||
> + moff == offsetof(struct sched_ext_ops, enable) ||
> + moff == offsetof(struct sched_ext_ops, set_weight) ||
> + moff == offsetof(struct sched_ext_ops, disable) ||
> + moff == offsetof(struct sched_ext_ops, exit_task) ||
> + moff == offsetof(struct sched_ext_ops, dump_task) ||
> + moff == offsetof(struct sched_ext_ops, dump_cpu))
> + return 0;
> +
> + return -EACCES;
> +}
> +
> +static int scx_kfunc_ids_select_cpu_filter(const struct bpf_prog *prog, u32 kfunc_id)
> +{
> + u32 moff;
> +
> + if (!btf_id_set8_contains(&scx_kfunc_ids_select_cpu, kfunc_id) ||
> + prog->aux->st_ops != &bpf_sched_ext_ops)
> + return 0;
> +
> + moff = prog->aux->attach_st_ops_member_off;
> + if (moff == offsetof(struct sched_ext_ops, select_cpu))
> + return 0;
> +
> + return scx_kfunc_ids_other_rqlocked_filter(prog, kfunc_id);
So, I think we just need to return -EACCES here.
> +}
> +
> static const struct btf_kfunc_id_set scx_kfunc_set_select_cpu = {
> .owner = THIS_MODULE,
> .set = &scx_kfunc_ids_select_cpu,
> + .filter = scx_kfunc_ids_select_cpu_filter,
> };
>
> static bool scx_dsq_insert_preamble(struct task_struct *p, u64 enq_flags)
> --
> 2.39.5
>
Thanks,
-Andrea
