On Fri, Oct 11, 2019 at 9:21 AM Stanislav Fomichev <sdf@xxxxxxxxxx> wrote:
>
> Even though we have the pointer to user_struct and can recover
> uid of the user who has created the program, it usually contains
> 0 (root) which is not very informative. Let's store the comm of the
> calling process and export it via bpf_prog_info. This should help
> answer the question "which process loaded this particular program".
>
> Signed-off-by: Stanislav Fomichev <sdf@xxxxxxxxxx>
> ---
> include/linux/bpf.h | 1 +
> include/uapi/linux/bpf.h | 2 ++
> kernel/bpf/syscall.c | 4 ++++
> 3 files changed, 7 insertions(+)
>
> diff --git a/include/linux/bpf.h b/include/linux/bpf.h
> index 5b9d22338606..b03ea396afe5 100644
> --- a/include/linux/bpf.h
> +++ b/include/linux/bpf.h
> @@ -421,6 +421,7 @@ struct bpf_prog_aux {
> struct work_struct work;
> struct rcu_head rcu;
> };
> + char created_by_comm[BPF_CREATED_COMM_LEN];
> };
>
> struct bpf_array {
> diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
> index a65c3b0c6935..4e883ecbba1e 100644
> --- a/include/uapi/linux/bpf.h
> +++ b/include/uapi/linux/bpf.h
> @@ -326,6 +326,7 @@ enum bpf_attach_type {
> #define BPF_F_NUMA_NODE (1U << 2)
>
> #define BPF_OBJ_NAME_LEN 16U
> +#define BPF_CREATED_COMM_LEN 16U
Nack.
16 bytes is going to be useless.
We found it the hard way with prog_name.
If you want to embed additional debug information
please use BTF for that.
