Re: [PATCH bpf-next 1/3] bpf: Add cookie to raw_tp bpf_link_info

[Jiri Olsa <olsajiri@gmail.com>]

On Fri, May 30, 2025 at 12:57:57AM +0800, Tao Chen wrote:
> After commit 68ca5d4eebb8 ("bpf: support BPF cookie in raw tracepoint
> (raw_tp, tp_btf) programs"), we can show the cookie in bpf_link_info
> like kprobe etc.
> 
> Signed-off-by: Tao Chen <chen.dylane@linux.dev>
> ---
>  include/uapi/linux/bpf.h       | 1 +
>  kernel/bpf/syscall.c           | 1 +
>  tools/include/uapi/linux/bpf.h | 1 +
>  3 files changed, 3 insertions(+)
> 
> diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
> index 07ee73cdf9..7d0ad5c2b6 100644
> --- a/include/uapi/linux/bpf.h
> +++ b/include/uapi/linux/bpf.h
> @@ -6644,6 +6644,7 @@ struct bpf_link_info {
>  		struct {
>  			__aligned_u64 tp_name; /* in/out: tp_name buffer ptr */
>  			__u32 tp_name_len;     /* in/out: tp_name buffer len */

there's hole now in here, let's add something like

  __u32 reserved;

jirka


> +			__u64 cookie;
>  		} raw_tracepoint;
>  		struct {
>  			__u32 attach_type;
> diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
> index 9794446bc8..1c3dbe44ac 100644
> --- a/kernel/bpf/syscall.c
> +++ b/kernel/bpf/syscall.c
> @@ -3687,6 +3687,7 @@ static int bpf_raw_tp_link_fill_link_info(const struct bpf_link *link,
>  		return -EINVAL;
>  
>  	info->raw_tracepoint.tp_name_len = tp_len + 1;
> +	info->raw_tracepoint.cookie = raw_tp_link->cookie;
>  
>  	if (!ubuf)
>  		return 0;
> diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
> index 07ee73cdf9..7d0ad5c2b6 100644
> --- a/tools/include/uapi/linux/bpf.h
> +++ b/tools/include/uapi/linux/bpf.h
> @@ -6644,6 +6644,7 @@ struct bpf_link_info {
>  		struct {
>  			__aligned_u64 tp_name; /* in/out: tp_name buffer ptr */
>  			__u32 tp_name_len;     /* in/out: tp_name buffer len */
> +			__u64 cookie;
>  		} raw_tracepoint;
>  		struct {
>  			__u32 attach_type;
> -- 
> 2.43.0
>