Hi Eduard,
On Mon, Jul 21, 2025 at 03:38:59PM -0700, Eduard Zingerman wrote:
> On Fri, 2025-07-18 at 16:25 +0100, Leo Yan wrote:
>
> [...]
>
> > +__bpf_kfunc int bpf_perf_event_aux_pause(void *p__map, u64 flags, u32
> > pause)
> > +{
> > + struct bpf_map *map = p__map;
> > + struct bpf_array *array = container_of(map, struct bpf_array, map);
>
> Verifier makes sure that p__map is a not null pointer to an object of
> type bpf_map, but it does not guarantee that the object is an instance
> of bpf_array.
> You need to check map->type, same way bpf_arena_alloc_pages() does.
Makes sense. Will do.
> > + unsigned int cpu = smp_processor_id();
> > + u64 index = flags & BPF_F_INDEX_MASK;
> > + struct bpf_event_entry *ee;
> > + int ret = 0;
> > +
> > + /* Disabling IRQ avoids race condition with perf event flows. */
> > + guard(irqsave)();
> > +
> > + if (unlikely(flags & ~(BPF_F_INDEX_MASK))) {
> > + ret = -EINVAL;
> > + goto out;
> > + }
> > +
> > + if (index == BPF_F_CURRENT_CPU)
> > + index = cpu;
> > +
> > + if (unlikely(index >= array->map.max_entries)) {
> > + ret = -E2BIG;
> > + goto out;
> > + }
> > +
> > + ee = READ_ONCE(array->ptrs[index]);
> > + if (!ee) {
> > + ret = -ENOENT;
> > + goto out;
> > + }
> > +
> > + if (!has_aux(ee->event))
> > + ret = -EINVAL;
I should refactor a bit for removing "goto out" and directly return
error cases.
Thanks for review and your suggestion in another reply.
Leo
> > +
> > + perf_event_aux_pause(ee->event, pause);
> > +out:
> > + return ret;
> > +}
>
> [...]
