selftests/bpf: add raw_tp_test_run

This test runs test_run for raw_tracepoint program. The test covers ctx
input, retval output, and proper handling of cpu_plus field.

Signed-off-by: Song Liu <[email protected]>

Author: liu-song-6

tools/testing/selftests/bpf/prog_tests/raw_tp_test_run.c

@@ -0,0 +1,73 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2019 Facebook */
+#include <test_progs.h>
+#include "bpf/libbpf_internal.h"
+#include "test_raw_tp_test_run.skel.h"
+
+static int duration;
+
+void test_raw_tp_test_run(void)
+{
+	struct bpf_prog_test_run_attr test_attr = {};
+	__u64 args[2] = {0x1234ULL, 0x5678ULL};
+	int comm_fd = -1, err, nr_online, i;
+	int expected_retval = 0x1234 + 0x5678;
+	struct test_raw_tp_test_run *skel;
+	char buf[] = "new_name";
+	bool *online = NULL;
+
+	err = parse_cpu_mask_file("/sys/devices/system/cpu/online", &online,
+				  &nr_online);
+	if (CHECK(err, "parse_cpu_mask_file", "err %d\n", err))
+		return;
+
+	skel = test_raw_tp_test_run__open_and_load();
+	if (CHECK(!skel, "skel_open", "failed to open skeleton\n"))
+		return;
+	err = test_raw_tp_test_run__attach(skel);
+	if (CHECK(err, "skel_attach", "skeleton attach failed: %d\n", err))
+		goto cleanup;
+
+	comm_fd = open("/proc/self/comm", O_WRONLY|O_TRUNC);
+	if (CHECK(comm_fd < 0, "open /proc/self/comm", "err %d\n", errno))
+		goto cleanup;
+
+	err = write(comm_fd, buf, sizeof(buf));
+	CHECK(err < 0, "task rename", "err %d", errno);
+
+	CHECK(skel->bss->count == 0, "check_count", "didn't increase\n");
+	CHECK(skel->data->on_cpu != 0xffffffff, "check_on_cpu", "got wrong value\n");
+
+	test_attr.prog_fd = bpf_program__fd(skel->progs.rename);
+	test_attr.ctx_in = args;
+	test_attr.ctx_size_in = sizeof(__u64);
+
+	err = bpf_prog_test_run_xattr(&test_attr);
+	CHECK(err == 0, "test_run", "should fail for too small ctx\n");
+
+	test_attr.ctx_size_in = sizeof(args);
+	err = bpf_prog_test_run_xattr(&test_attr);
+	CHECK(err < 0, "test_run", "err %d\n", errno);
+	CHECK(test_attr.retval != expected_retval, "check_retval",
+	      "expect 0x%x, got 0x%x\n", expected_retval, test_attr.retval);
+
+	for (i = 0; i < nr_online; i++)
+		if (online[i]) {
+			DECLARE_LIBBPF_OPTS(bpf_prog_test_run_opts, opts,
+				.cpu_plus = i + 1,
+			);
+
+			test_attr.retval = 0;
+			err = bpf_prog_test_run_xattr_opts(&test_attr, &opts);
+			CHECK(err < 0, "test_run_with_opts", "err %d\n", errno);
+			CHECK(skel->data->on_cpu != i, "check_on_cpu",
+			      "got wrong value\n");
+			CHECK(test_attr.retval != expected_retval,
+			      "check_retval", "expect 0x%x, got 0x%x\n",
+			      expected_retval, test_attr.retval);
+		}
+cleanup:
+	close(comm_fd);
+	test_raw_tp_test_run__destroy(skel);
+	free(online);
+}

tools/testing/selftests/bpf/progs/test_raw_tp_test_run.c

@@ -0,0 +1,26 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2020 Facebook */
+
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_endian.h>
+#include <bpf/bpf_tracing.h>
+
+__u32 count = 0;
+__u32 on_cpu = 0xffffffff;
+
+SEC("raw_tp/task_rename")
+int BPF_PROG(rename, struct task_struct *task, char *comm)
+{
+
+	count++;
+	if ((unsigned long long) task == 0x1234 &&
+	    (unsigned long long) comm == 0x5678) {
+		on_cpu = bpf_get_smp_processor_id();
+		return (int)task + (int)comm;
+	}
+
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";