On Mon, Oct 25, 2021 at 2:18 PM Lorenzo Bianconi <lorenzo@xxxxxxxxxx> wrote:
>
> Introduce bpf_map_get_xdp_prog to load an eBPF program on
> CPUMAP/DEVMAP entries since both of them share the same code.
>
> Signed-off-by: Lorenzo Bianconi <lorenzo@xxxxxxxxxx>
> ---
> include/linux/bpf.h | 2 ++
> kernel/bpf/core.c | 17 +++++++++++++++++
> kernel/bpf/cpumap.c | 12 ++++--------
> kernel/bpf/devmap.c | 16 ++++++----------
> 4 files changed, 29 insertions(+), 18 deletions(-)
>
> diff --git a/include/linux/bpf.h b/include/linux/bpf.h
> index 26bf8c865103..891936b54b55 100644
> --- a/include/linux/bpf.h
> +++ b/include/linux/bpf.h
> @@ -1910,6 +1910,8 @@ static inline struct bpf_prog *bpf_prog_get_type(u32 ufd,
> return bpf_prog_get_type_dev(ufd, type, false);
> }
>
> +struct bpf_prog *bpf_map_get_xdp_prog(struct bpf_map *map, int fd,
> + enum bpf_attach_type attach_type);
> void __bpf_free_used_maps(struct bpf_prog_aux *aux,
> struct bpf_map **used_maps, u32 len);
>
> diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
> index dee91a2eea7b..7e72c21b6589 100644
> --- a/kernel/bpf/core.c
> +++ b/kernel/bpf/core.c
> @@ -2228,6 +2228,23 @@ void __bpf_free_used_maps(struct bpf_prog_aux *aux,
> }
> }
>
> +struct bpf_prog *bpf_map_get_xdp_prog(struct bpf_map *map, int fd,
> + enum bpf_attach_type attach_type)
> +{
> + struct bpf_prog *prog;
> +
> + prog = bpf_prog_get_type(fd, BPF_PROG_TYPE_XDP);
> + if (IS_ERR(prog))
> + return prog;
> +
> + if (prog->expected_attach_type != attach_type) {
> + bpf_prog_put(prog);
> + return ERR_PTR(-EINVAL);
> + }
> +
> + return prog;
> +}
It is supposed to be a cleanup... but...
1. it's tweaking __cpu_map_load_bpf_program()
to pass extra 'map' argument further into this helper,
but the 'map' is unused.
2. bpf_map_get_xdp_prog is a confusing name. what 'map' doing in there?
3. it's placed in core.c while it's really cpumap/devmap only.
I suggest leaving the code as-is.
