On Mon, Jun 23, 2025 at 8:13 PM Kumar Kartikeya Dwivedi
<memxor@xxxxxxxxx> wrote:
>
> Add a convenience macro to print data to the BPF streams. BPF_STDOUT and
> BPF_STDERR stream IDs in the vmlinux.h can be passed to the macro to
> print to the respective streams.
>
> Acked-by: Eduard Zingerman <eddyz87@xxxxxxxxx>
> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx>
> ---
> tools/lib/bpf/bpf_helpers.h | 16 ++++++++++++++++
> 1 file changed, 16 insertions(+)
>
Acked-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
> diff --git a/tools/lib/bpf/bpf_helpers.h b/tools/lib/bpf/bpf_helpers.h
> index a50773d4616e..76b127a9f24d 100644
> --- a/tools/lib/bpf/bpf_helpers.h
> +++ b/tools/lib/bpf/bpf_helpers.h
> @@ -314,6 +314,22 @@ enum libbpf_tristate {
> ___param, sizeof(___param)); \
> })
>
> +extern int bpf_stream_vprintk(int stream_id, const char *fmt__str, const void *args,
> + __u32 len__sz, void *aux__prog) __weak __ksym;
> +
> +#define bpf_stream_printk(stream_id, fmt, args...) \
> +({ \
> + static const char ___fmt[] = fmt; \
> + unsigned long long ___param[___bpf_narg(args)]; \
> + \
> + _Pragma("GCC diagnostic push") \
> + _Pragma("GCC diagnostic ignored \"-Wint-conversion\"") \
> + ___bpf_fill(___param, args); \
> + _Pragma("GCC diagnostic pop") \
> + \
> + bpf_stream_vprintk(stream_id, ___fmt, ___param, sizeof(___param), NULL);\
> +})
> +
> /* Use __bpf_printk when bpf_printk call has 3 or fewer fmt args
> * Otherwise use __bpf_vprintk
> */
> --
> 2.47.1
>
