bpf: Do not walk twice the map on free

If someone stores both a timer and a workqueue in a map, on free
we would walk it twice.

Add a check in array_map_free_timers_wq and free the timers and
workqueues if they are present.

Fixes: 246331e3f1 ("bpf: allow struct bpf_wq to be embedded in arraymaps and hashmaps")
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/bpf/20240430-bpf-next-v3-1-27afe7f3b17c@kernel.org
This commit is contained in:
Benjamin Tissoires 2024-04-30 12:43:24 +02:00 committed by Daniel Borkmann
parent 1bba3b3d37
commit b98a5c68cc

View File

@ -436,13 +436,14 @@ static void array_map_free_timers_wq(struct bpf_map *map)
/* We don't reset or free fields other than timer and workqueue
* on uref dropping to zero.
*/
if (btf_record_has_field(map->record, BPF_TIMER))
for (i = 0; i < array->map.max_entries; i++)
bpf_obj_free_timer(map->record, array_map_elem_ptr(array, i));
if (btf_record_has_field(map->record, BPF_WORKQUEUE))
for (i = 0; i < array->map.max_entries; i++)
bpf_obj_free_workqueue(map->record, array_map_elem_ptr(array, i));
if (btf_record_has_field(map->record, BPF_TIMER | BPF_WORKQUEUE)) {
for (i = 0; i < array->map.max_entries; i++) {
if (btf_record_has_field(map->record, BPF_TIMER))
bpf_obj_free_timer(map->record, array_map_elem_ptr(array, i));
if (btf_record_has_field(map->record, BPF_WORKQUEUE))
bpf_obj_free_workqueue(map->record, array_map_elem_ptr(array, i));
}
}
}
/* Called when map->refcnt goes to zero, either from workqueue or from syscall */