Re: [PATCH net-next v4 3/4] bpf: add helper bpf_perf_prog_read_value

  #ifdef CONFIG_CGROUP_PERF

diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 2c68b9e..ba77022 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h

@@ -590,6 +590,13 @@ union bpf_attr {
   *     @buf: buf to fill
   *     @buf_size: size of the buf
   *     Return: 0 on success or negative error code
+ *
+ * int bpf_perf_prog_read_value(ctx, buf, buf_size)
+ *     read perf prog attached perf event counter and enabled/running time
+ *     @ctx: pointer to ctx
+ *     @buf: buf to fill
+ *     @buf_size: size of the buf
+ *     Return : 0 on success or negative error code
   */
  #define __BPF_FUNC_MAPPER(FN)		\
  	FN(unspec),			\

@@ -647,6 +654,7 @@ union bpf_attr {
  	FN(sk_redirect_map),		\
  	FN(sock_map_update),		\
  	FN(perf_event_read_value),		\
+	FN(perf_prog_read_value),		\

  /* integer value in 'imm' field of BPF_CALL instruction selects which helper
   * function eBPF program intends to call

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 2d5bbe5..d039086 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c

@@ -8081,6 +8081,7 @@ static void bpf_overflow_handler(struct perf_event *event,
  	struct bpf_perf_event_data_kern ctx = {
  		.data = data,
  		.regs = regs,
+		.event = event,
  	};
  	int ret = 0;

diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 39ce5d9..596b5c9 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c

@@ -603,6 +603,18 @@ BPF_CALL_3(bpf_get_stackid_tp, void *, tp_buff, struct bpf_map *, map,
  			       flags, 0, 0);
  }

+BPF_CALL_3(bpf_perf_prog_read_value_tp, void *, ctx, struct bpf_perf_event_value *,
+	buf, u32, size)

  static const struct bpf_func_proto bpf_get_stackid_proto_tp = {
  	.func		= bpf_get_stackid_tp,
  	.gpl_only	= true,

@@ -612,6 +624,15 @@ static const struct bpf_func_proto bpf_get_stackid_proto_tp = {
  	.arg3_type	= ARG_ANYTHING,
  };

+static const struct bpf_func_proto bpf_perf_prog_read_value_proto_tp = {
+         .func           = bpf_perf_prog_read_value_tp,
+         .gpl_only       = true,
+         .ret_type       = RET_INTEGER,
+         .arg1_type      = ARG_PTR_TO_CTX,
+         .arg2_type      = ARG_PTR_TO_UNINIT_MEM,

+         .arg3_type      = ARG_CONST_SIZE,
+};
+
  static const struct bpf_func_proto *tp_prog_func_proto(enum bpf_func_id func_id)
  {
  	switch (func_id) {

@@ -619,6 +640,8 @@ static const struct bpf_func_proto *tp_prog_func_proto(enum bpf_func_id func_id)
  		return &bpf_perf_event_output_proto_tp;
  	case BPF_FUNC_get_stackid:
  		return &bpf_get_stackid_proto_tp;
+	case BPF_FUNC_perf_prog_read_value:
+		return &bpf_perf_prog_read_value_proto_tp;
  	default:
  		return tracing_func_proto(func_id);
  	}