On 11/23/21 11:28 AM, Andrii Nakryiko wrote:
> On Sun, Nov 21, 2021 at 5:55 AM Hengqi Chen <hengqi.chen@xxxxxxxxx> wrote:
>>
>> Add testcase for BPF_MAP_TYPE_PROG_ARRAY static initialization.
>>
>> Signed-off-by: Hengqi Chen <hengqi.chen@xxxxxxxxx>
>> ---
>
> It's a bit too minimal, let's actually trigger the program and make
> sure that tail call program gets executed. Please also make sure that
> you filter by pid like other tracing progs do (I suggest using
> usleep(1) and raw_tracepoint program for sys_enter, as the simplest
> set up).
>
Will implement what you suggest here. Thanks.
>> .../bpf/prog_tests/prog_array_init.c | 27 +++++++++++++++++
>> .../bpf/progs/test_prog_array_init.c | 30 +++++++++++++++++++
>> 2 files changed, 57 insertions(+)
>> create mode 100644 tools/testing/selftests/bpf/prog_tests/prog_array_init.c
>> create mode 100644 tools/testing/selftests/bpf/progs/test_prog_array_init.c
>>
>> diff --git a/tools/testing/selftests/bpf/prog_tests/prog_array_init.c b/tools/testing/selftests/bpf/prog_tests/prog_array_init.c
>> new file mode 100644
>> index 000000000000..2fbf6946a0b6
>> --- /dev/null
>> +++ b/tools/testing/selftests/bpf/prog_tests/prog_array_init.c
>> @@ -0,0 +1,27 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>> +/* Copyright (c) 2021 Hengqi Chen */
>> +
>> +#include <test_progs.h>
>> +#include <sys/un.h>
>> +#include "test_prog_array_init.skel.h"
>> +
>> +void test_prog_array_init(void)
>> +{
>> + struct test_prog_array_init *skel;
>> + int err;
>> +
>> + skel = test_prog_array_init__open();
>> + if (!ASSERT_OK_PTR(skel, "could not open BPF object"))
>> + return;
>> +
>> + err = test_prog_array_init__load(skel);
>> + if (!ASSERT_OK(err, "could not load BPF object"))
>> + goto cleanup;
>> +
>> + err = test_prog_array_init__attach(skel);
>> + if (!ASSERT_OK(err, "could not attach BPF object"))
>> + goto cleanup;
>> +
>> +cleanup:
>> + test_prog_array_init__destroy(skel);
>> +}
>> diff --git a/tools/testing/selftests/bpf/progs/test_prog_array_init.c b/tools/testing/selftests/bpf/progs/test_prog_array_init.c
>> new file mode 100644
>> index 000000000000..e97204dd5443
>> --- /dev/null
>> +++ b/tools/testing/selftests/bpf/progs/test_prog_array_init.c
>> @@ -0,0 +1,30 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>> +/* Copyright (c) 2021 Hengqi Chen */
>> +
>> +#include "vmlinux.h"
>> +#include <bpf/bpf_helpers.h>
>> +#include <bpf/bpf_tracing.h>
>> +
>> +SEC("socket")
>> +int tailcall_1(void *ctx)
>> +{
>
> let's add some global variable that will be set by the tail call
> program, so that we know that correct slot and correct program was set
>
Will do.
>> + return 0;
>> +}
>> +
>> +struct {
>> + __uint(type, BPF_MAP_TYPE_PROG_ARRAY);
>> + __uint(max_entries, 2);
>> + __uint(key_size, sizeof(__u32));
>> + __array(values, int (void *));
>> +} prog_array_init SEC(".maps") = {
>> + .values = {
>> + [1] = (void *)&tailcall_1,
>> + },
>> +};
>> +
>> +SEC("socket")
>> +int BPF_PROG(entry)
>> +{
>
> BPF_PROG doesn't really help, it just hides ctx which you are actually
> using below, so let's just stick to `int entry(void *ctx)` here.
>
Ack.
>> + bpf_tail_call(ctx, &prog_array_init, 1);
>> + return 0;
>> +}
>> --
>> 2.30.2
---Hengqi
