[PATCH dwarves v6 4/6] bpf: Create fentry/fexit/fmod_ret links through BPF_LINK_CREATE

[Kui-Feng Lee <kuifeng@fb.com>]

Make fentry/fexit/fmod_ret as valid attach-types for BPF_LINK_CREATE.
Pass a cookie along with BPF_LINK_CREATE requests.

Signed-off-by: Kui-Feng Lee <kuifeng@fb.com>
---
 include/uapi/linux/bpf.h       | 7 +++++++
 kernel/bpf/syscall.c           | 9 +++++++++
 tools/include/uapi/linux/bpf.h | 7 +++++++
 3 files changed, 23 insertions(+)

diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index a4f557338af7..780be5a8ae39 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -1490,6 +1490,13 @@ union bpf_attr {
 				__aligned_u64	addrs;
 				__aligned_u64	cookies;
 			} kprobe_multi;
+			struct {
+				/* black box user-provided value passed through
+				 * to BPF program at the execution time and
+				 * accessible through bpf_get_attach_cookie() BPF helper
+				 */
+				__u64		cookie;
+			} tracing;
 		};
 	} link_create;
 
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 966f2d40ae55..ca14b0a2e222 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -3189,6 +3189,10 @@ attach_type_to_prog_type(enum bpf_attach_type attach_type)
 		return BPF_PROG_TYPE_SK_LOOKUP;
 	case BPF_XDP:
 		return BPF_PROG_TYPE_XDP;
+	case BPF_TRACE_FENTRY:
+	case BPF_TRACE_FEXIT:
+	case BPF_MODIFY_RETURN:
+		return BPF_PROG_TYPE_TRACING;
 	default:
 		return BPF_PROG_TYPE_UNSPEC;
 	}
@@ -4254,6 +4258,11 @@ static int tracing_bpf_link_attach(const union bpf_attr *attr, bpfptr_t uattr,
 					       attr->link_create.target_fd,
 					       attr->link_create.target_btf_id,
 					       0);
+	else if (prog->type == BPF_PROG_TYPE_TRACING)
+		return bpf_tracing_prog_attach(prog,
+					       0,
+					       0,
+					       attr->link_create.tracing.cookie);
 
 	return -EINVAL;
 }
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index a4f557338af7..780be5a8ae39 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -1490,6 +1490,13 @@ union bpf_attr {
 				__aligned_u64	addrs;
 				__aligned_u64	cookies;
 			} kprobe_multi;
+			struct {
+				/* black box user-provided value passed through
+				 * to BPF program at the execution time and
+				 * accessible through bpf_get_attach_cookie() BPF helper
+				 */
+				__u64		cookie;
+			} tracing;
 		};
 	} link_create;
 
-- 
2.30.2