> On Sep 24, 2020, at 6:01 PM, John Fastabend <john.fastab...@gmail.com> wrote:
>
> Song Liu wrote:
>> This test runs test_run for raw_tracepoint program. The test covers ctx
>> input, retval output, and running on correct cpu.
>>
>> Signed-off-by: Song Liu <songliubrav...@fb.com>
>> ---
>
> [...]
>
>> +void test_raw_tp_test_run(void)
>> +{
>> + struct bpf_prog_test_run_attr test_attr = {};
>> + int comm_fd = -1, err, nr_online, i, prog_fd;
>> + __u64 args[2] = {0x1234ULL, 0x5678ULL};
>> + 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"))
>> + goto cleanup;
>> +
>> + 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");
>> +
>> + prog_fd = bpf_program__fd(skel->progs.rename);
>> + test_attr.prog_fd = prog_fd;
>> + 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_test_run_opts, opts,
>> + .ctx_in = args,
>> + .ctx_size_in = sizeof(args),
>> + .flags = BPF_F_TEST_RUN_ON_CPU,
>> + .retval = 0,
>> + .cpu = i,
>> + );
>> +
>> + err = bpf_prog_test_run_opts(prog_fd, &opts);
>> + CHECK(err < 0, "test_run_opts", "err %d\n", errno);
>> + CHECK(skel->data->on_cpu != i, "check_on_cpu",
>> + "expect %d got %d\n", i, skel->data->on_cpu);
>> + CHECK(opts.retval != expected_retval,
>> + "check_retval", "expect 0x%x, got 0x%x\n",
>> + expected_retval, opts.retval);
>> +
>> + if (i == 0) {
>> + /* invalid cpu ID should fail with ENXIO */
>> + opts.cpu = 0xffffffff;
>> + err = bpf_prog_test_run_opts(prog_fd, &opts);
>> + CHECK(err != -1 || errno != ENXIO,
>> + "test_run_opts_fail",
>> + "should failed with ENXIO\n");
>> + } else {
>
> One more request...
>
> How about pull this if/else branch out of the for loop here? It feels a bit
> clumsy as-is imo. Also is it worthwhile to bang on the else branch for evey
> cpu I would think testing for any non-zero value should be sufficient.
I thought about both these two directions. The biggest benefit of current
version is that we can reuse the DECLARE_LIBBPF_OPTS() in this loop. Moving
it to the beginning of the function bothers me a little bit..
Thanks,
Song
