selftests/bpf: Test for syscall program type

bpf_prog_type_syscall is a program that creates a bpf map,
updates it, and loads another bpf program using bpf_sys_bpf() helper.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210514003623.28033-6-alexei.starovoitov@gmail.com

1 files changed, 52 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/prog_tests/syscall.c b/tools/testing/selftests/bpf/prog_tests/syscall.c
new file mode 100644
index 000000000000..1badd37148a1
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/syscall.c
@@ -0,0 +1,52 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2021 Facebook */
+#include <test_progs.h>
+#include "syscall.skel.h"
+
+struct args {
+	__u64 log_buf;
+	__u32 log_size;
+	int max_entries;
+	int map_fd;
+	int prog_fd;
+};
+
+void test_syscall(void)
+{
+	static char verifier_log[8192];
+	struct args ctx = {
+		.max_entries = 1024,
+		.log_buf = (uintptr_t) verifier_log,
+		.log_size = sizeof(verifier_log),
+	};
+	struct bpf_prog_test_run_attr tattr = {
+		.ctx_in = &ctx,
+		.ctx_size_in = sizeof(ctx),
+	};
+	struct syscall *skel = NULL;
+	__u64 key = 12, value = 0;
+	int err;
+
+	skel = syscall__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "skel_load"))
+		goto cleanup;
+
+	tattr.prog_fd = bpf_program__fd(skel->progs.bpf_prog);
+	err = bpf_prog_test_run_xattr(&tattr);
+	ASSERT_EQ(err, 0, "err");
+	ASSERT_EQ(tattr.retval, 1, "retval");
+	ASSERT_GT(ctx.map_fd, 0, "ctx.map_fd");
+	ASSERT_GT(ctx.prog_fd, 0, "ctx.prog_fd");
+	ASSERT_OK(memcmp(verifier_log, "processed", sizeof("processed") - 1),
+		  "verifier_log");
+
+	err = bpf_map_lookup_elem(ctx.map_fd, &key, &value);
+	ASSERT_EQ(err, 0, "map_lookup");
+	ASSERT_EQ(value, 34, "map lookup value");
+cleanup:
+	syscall__destroy(skel);
+	if (ctx.prog_fd > 0)
+		close(ctx.prog_fd);
+	if (ctx.map_fd > 0)
+		close(ctx.map_fd);
+}