Re: [v2 PATCH bpf-next 2/2] bpf/selftests: Check errno when percpu map value size exceeds

[Tao Chen]

在 2024/9/10 04:16, Andrii Nakryiko 写道:
> On Mon, Sep 9, 2024 at 12:14 AM Tao Chen <chen.dylane@xxxxxxxxx> wrote:
> > This test case checks the errno message when percpu map value size
> > exceeds PCPU_MIN_UNIT_SIZE.
> >
> > root@debian:~# ./test_progs -t map_init
> >   #160/1   map_init/pcpu_map_init:OK
> >   #160/2   map_init/pcpu_lru_map_init:OK
> >   #160/3   map_init/pcpu map value size:OK
> >   #160     map_init:OK
> > Summary: 1/3 PASSED, 0 SKIPPED, 0 FAILED
> >
> > Signed-off-by: Tao Chen <chen.dylane@xxxxxxxxx>
> > Signed-off-by: jinke han <jinkehan@xxxxxxxxxxxxxx>
> > ---
> >   .../selftests/bpf/prog_tests/map_init.c       | 32 +++++++++++++++++++
> >   .../selftests/bpf/progs/test_map_init.c       |  6 ++++
> >   2 files changed, 38 insertions(+)
> >
> > diff --git a/tools/testing/selftests/bpf/prog_tests/map_init.c b/tools/testing/selftests/bpf/prog_tests/map_init.c
> > index 14a31109dd0e..7f1a6fa3679f 100644
> > --- a/tools/testing/selftests/bpf/prog_tests/map_init.c
> > +++ b/tools/testing/selftests/bpf/prog_tests/map_init.c
> > @@ -6,6 +6,7 @@
> >
> >   #define TEST_VALUE 0x1234
> >   #define FILL_VALUE 0xdeadbeef
> > +#define PCPU_MIN_UNIT_SIZE 32768
> >
> >   static int nr_cpus;
> >   static int duration;
> > @@ -118,6 +119,35 @@ static int check_values_one_cpu(pcpu_map_value_t *value, map_value_t expected)
> >
> >          return 0;
> >   }
> > +/*
> > + * percpu map value size is bound by PCPU_MIN_UNIT_SIZE
> > + * check the errno when the value exceed PCPU_MIN_UNIT_SIZE
> > + */
> > +static void test_pcpu_map_value_size(void)
> > +{
> > +       struct test_map_init *skel;
> > +       int err;
> > +       int value_sz = PCPU_MIN_UNIT_SIZE + 1;
> > +       enum bpf_map_type map_types[] = { BPF_MAP_TYPE_PERCPU_ARRAY,
> > +                                         BPF_MAP_TYPE_PERCPU_HASH,
> > +                                         BPF_MAP_TYPE_LRU_PERCPU_HASH };
> > +       for (int i = 0; i < ARRAY_SIZE(map_types); i++) {
> > +               skel = test_map_init__open();
> > +               if (!ASSERT_OK_PTR(skel, "skel_open"))
> > +                       return;
> > +               err = bpf_map__set_type(skel->maps.hashmap2, map_types[i]);
> > +               if (!ASSERT_OK(err, "bpf_map__set_type"))
> > +                       goto error;
> > +               err = bpf_map__set_value_size(skel->maps.hashmap2, value_sz);
> > +               if (!ASSERT_OK(err, "bpf_map__set_value_size"))
> > +                       goto error;
> > +
> > +               err = test_map_init__load(skel);
> > +               ASSERT_EQ(err, -E2BIG, "skel_load");
>
> This is quite an overkill to test map creation. It will be much more
> straightforward to just use low-level bpf_map_create() API, can you
> please make use of that instead?
>
> pw-bot: cr

Ok, i will use the bpf_map_create API in v3.

> > +error:
> > +               test_map_init__destroy(skel);
> > +       }
> > +}
> >
> >   /* Add key=1 elem with values set for all CPUs
> >    * Delete elem key=1
> > @@ -211,4 +241,6 @@ void test_map_init(void)
> >                  test_pcpu_map_init();
> >          if (test__start_subtest("pcpu_lru_map_init"))
> >                  test_pcpu_lru_map_init();
> > +       if (test__start_subtest("pcpu map value size"))
> > +               test_pcpu_map_value_size();
> >   }
> > diff --git a/tools/testing/selftests/bpf/progs/test_map_init.c b/tools/testing/selftests/bpf/progs/test_map_init.c
> > index c89d28ead673..7a772cbf0570 100644
> > --- a/tools/testing/selftests/bpf/progs/test_map_init.c
> > +++ b/tools/testing/selftests/bpf/progs/test_map_init.c
> > @@ -15,6 +15,12 @@ struct {
> >          __type(value, __u64);
> >   } hashmap1 SEC(".maps");
> >
> > +struct {
> > +       __uint(type, BPF_MAP_TYPE_HASH);
> > +       __uint(max_entries, 1);
> > +       __type(key, __u32);
> > +       __type(value, __u64);
> > +} hashmap2 SEC(".maps");
> >
> >   SEC("tp/syscalls/sys_enter_getpgid")
> >   int sysenter_getpgid(const void *ctx)
> > --
> > 2.25.1


--
Best Regards
Dylane Chen