On Sun, Mar 16, 2025 at 02:01:03PM -0400, Emil Tsalapatis wrote:
> The perf_event_read_event_output helper is currently only available to
> tracing protrams, but is useful for other BPF programs like sched_ext
> schedulers. When the helper is available, provide its bpf_func_proto
> directly from the bpf core.
please add bpf-next to the subject, otherwise lgtm
Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>
jirka
>
> Signed-off-by: Emil Tsalapatis (Meta) <emil@xxxxxxxxxxxxxxx>
> ---
> include/linux/bpf.h | 2 ++
> kernel/bpf/core.c | 5 +++++
> kernel/bpf/helpers.c | 2 ++
> kernel/trace/bpf_trace.c | 5 +++++
> 4 files changed, 14 insertions(+)
>
> diff --git a/include/linux/bpf.h b/include/linux/bpf.h
> index 0d7b70124d81..973a88d9b52b 100644
> --- a/include/linux/bpf.h
> +++ b/include/linux/bpf.h
> @@ -2059,6 +2059,8 @@ int bpf_prog_calc_tag(struct bpf_prog *fp);
> const struct bpf_func_proto *bpf_get_trace_printk_proto(void);
> const struct bpf_func_proto *bpf_get_trace_vprintk_proto(void);
>
> +const struct bpf_func_proto *bpf_get_perf_event_read_value_proto(void);
> +
> typedef unsigned long (*bpf_ctx_copy_t)(void *dst, const void *src,
> unsigned long off, unsigned long len);
> typedef u32 (*bpf_convert_ctx_access_t)(enum bpf_access_type type,
> diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
> index 62cb9557ad3b..ba6b6118cf50 100644
> --- a/kernel/bpf/core.c
> +++ b/kernel/bpf/core.c
> @@ -2972,6 +2972,11 @@ const struct bpf_func_proto * __weak bpf_get_trace_vprintk_proto(void)
> return NULL;
> }
>
> +const struct bpf_func_proto * __weak bpf_get_perf_event_read_value_proto(void)
> +{
> + return NULL;
> +}
> +
> u64 __weak
> bpf_event_output(struct bpf_map *map, u64 flags, void *meta, u64 meta_size,
> void *ctx, u64 ctx_size, bpf_ctx_copy_t ctx_copy)
> diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
> index 5449756ba102..ddaa41a70676 100644
> --- a/kernel/bpf/helpers.c
> +++ b/kernel/bpf/helpers.c
> @@ -2056,6 +2056,8 @@ bpf_base_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
> return &bpf_task_pt_regs_proto;
> case BPF_FUNC_trace_vprintk:
> return bpf_get_trace_vprintk_proto();
> + case BPF_FUNC_perf_event_read_value:
> + return bpf_get_perf_event_read_value_proto();
> default:
> return NULL;
> }
> diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
> index 13bef2462e94..6b07fa7081d9 100644
> --- a/kernel/trace/bpf_trace.c
> +++ b/kernel/trace/bpf_trace.c
> @@ -607,6 +607,11 @@ static const struct bpf_func_proto bpf_perf_event_read_value_proto = {
> .arg4_type = ARG_CONST_SIZE,
> };
>
> +const struct bpf_func_proto *bpf_get_perf_event_read_value_proto(void)
> +{
> + return &bpf_perf_event_read_value_proto;
> +}
> +
> static __always_inline u64
> __bpf_perf_event_output(struct pt_regs *regs, struct bpf_map *map,
> u64 flags, struct perf_raw_record *raw,
> --
> 2.47.1
>
>
