libbpf: add support for ctx_{size, }_{in, out} in BPF_PROG_TEST_RUN

Support recently introduced input/output context for test runs.
We extend only bpf_prog_test_run_xattr. bpf_prog_test_run is
unextendable and left as is.
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

tools/include/uapi/linux/bpf.h

@@ -412,6 +412,13 @@ union bpf_attr {
 		__aligned_u64	data_out;
 		__u32		repeat;
 		__u32		duration;
+		__u32		ctx_size_in;	/* input: len of ctx_in */
+		__u32		ctx_size_out;	/* input/output: len of ctx_out
+						 *   returns ENOSPC if ctx_out
+						 *   is too small.
+						 */
+		__aligned_u64	ctx_in;
+		__aligned_u64	ctx_out;
 	} test;
 
 	struct { /* anonymous struct used by BPF_*_GET_*_ID */

tools/lib/bpf/bpf.c

@@ -554,10 +554,15 @@ int bpf_prog_test_run_xattr(struct bpf_prog_test_run_attr *test_attr)
 	attr.test.data_out = ptr_to_u64(test_attr->data_out);
 	attr.test.data_size_in = test_attr->data_size_in;
 	attr.test.data_size_out = test_attr->data_size_out;
+	attr.test.ctx_in = ptr_to_u64(test_attr->ctx_in);
+	attr.test.ctx_out = ptr_to_u64(test_attr->ctx_out);
+	attr.test.ctx_size_in = test_attr->ctx_size_in;
+	attr.test.ctx_size_out = test_attr->ctx_size_out;
 	attr.test.repeat = test_attr->repeat;
 
 	ret = sys_bpf(BPF_PROG_TEST_RUN, &attr, sizeof(attr));
 	test_attr->data_size_out = attr.test.data_size_out;
+	test_attr->ctx_size_out = attr.test.ctx_size_out;
 	test_attr->retval = attr.test.retval;
 	test_attr->duration = attr.test.duration;
 	return ret;

tools/lib/bpf/bpf.h

@@ -136,6 +136,11 @@ struct bpf_prog_test_run_attr {
 			      * out: length of data_out */
 	__u32 retval;        /* out: return code of the BPF program */
 	__u32 duration;      /* out: average per repetition in ns */
+	const void *ctx_in; /* optional */
+	__u32 ctx_size_in;
+	void *ctx_out;      /* optional */
+	__u32 ctx_size_out; /* in: max length of ctx_out
+			     * out: length of cxt_out */
 };
 
 LIBBPF_API int bpf_prog_test_run_xattr(struct bpf_prog_test_run_attr *test_attr);