Re: [PATCH v4 1/4] bpf: Export bpf_dynptr_get_size()

From: Joanne Koong
Date: Tue Jun 14 2022 - 13:51:02 EST


On Tue, Jun 14, 2022 at 4:54 AM Roberto Sassu <roberto.sassu@xxxxxxxxxx> wrote:
>
> Export bpf_dynptr_get_size(), so that kernel code dealing with eBPF dynamic
> pointers can obtain the real size of data carried by this data structure.
>
> Cc: Joanne Koong <joannelkoong@xxxxxxxxx>
> Signed-off-by: Roberto Sassu <roberto.sassu@xxxxxxxxxx>

LGTM

Acked-by: Joanne Koong <joannelkoong@xxxxxxxxx>

> ---
> include/linux/bpf.h | 1 +
> kernel/bpf/helpers.c | 2 +-
> 2 files changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/include/linux/bpf.h b/include/linux/bpf.h
> index 8e6092d0ea95..6eb03a0c9687 100644
> --- a/include/linux/bpf.h
> +++ b/include/linux/bpf.h
> @@ -2420,5 +2420,6 @@ void bpf_dynptr_init(struct bpf_dynptr_kern *ptr, void *data,
> enum bpf_dynptr_type type, u32 offset, u32 size);
> void bpf_dynptr_set_null(struct bpf_dynptr_kern *ptr);
> int bpf_dynptr_check_size(u32 size);
> +u32 bpf_dynptr_get_size(struct bpf_dynptr_kern *ptr);
>
> #endif /* _LINUX_BPF_H */
> diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
> index 225806a02efb..29e1810afaf6 100644
> --- a/kernel/bpf/helpers.c
> +++ b/kernel/bpf/helpers.c
> @@ -1430,7 +1430,7 @@ static void bpf_dynptr_set_type(struct bpf_dynptr_kern *ptr, enum bpf_dynptr_typ
> ptr->size |= type << DYNPTR_TYPE_SHIFT;
> }
>
> -static u32 bpf_dynptr_get_size(struct bpf_dynptr_kern *ptr)
> +u32 bpf_dynptr_get_size(struct bpf_dynptr_kern *ptr)
> {
> return ptr->size & DYNPTR_SIZE_MASK;
> }
> --
> 2.25.1
>