On Tue, Feb 21, 2023 at 5:47 PM Yafang Shao <laoar.shao@xxxxxxxxx> wrote:
>
> We have implemented memory usage callback for all maps, and we enforce
> any newly added map having a callback as well. Show a warning if it
> doesn't have.
>
> Signed-off-by: Yafang Shao <laoar.shao@xxxxxxxxx>
> ---
> kernel/bpf/syscall.c | 10 +++-------
> 1 file changed, 3 insertions(+), 7 deletions(-)
>
> diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
> index e12b03e..d814d4e 100644
> --- a/kernel/bpf/syscall.c
> +++ b/kernel/bpf/syscall.c
> @@ -775,13 +775,9 @@ static fmode_t map_get_sys_perms(struct bpf_map *map, struct fd f)
> /* Show the memory usage of a bpf map */
> static u64 bpf_map_memory_usage(const struct bpf_map *map)
> {
> - unsigned long size;
> -
> - if (map->ops->map_mem_usage)
> - return map->ops->map_mem_usage(map);
> -
> - size = round_up(map->key_size + bpf_map_value_size(map), 8);
> - return round_up(map->max_entries * size, PAGE_SIZE);
> + if (WARN_ON_ONCE(!map->ops->map_mem_usage))
> + return 0;
Since all maps are converted, let's do this check earlier.
Like during find_and_alloc_map.
And without WARN.
