On Mon, Oct 8, 2018 at 3:34 AM Lorenz Bauer <lmb@xxxxxxxxxxxxxx> wrote:
>
> Check that iterating two separate hash maps produces the same
> order of keys if BPF_F_ZERO_SEED is used.
>
> Signed-off-by: Lorenz Bauer <lmb@xxxxxxxxxxxxxx>
> ---
> tools/testing/selftests/bpf/test_maps.c | 68 +++++++++++++++++++++----
> 1 file changed, 57 insertions(+), 11 deletions(-)
>
> diff --git a/tools/testing/selftests/bpf/test_maps.c b/tools/testing/selftests/bpf/test_maps.c
> index 9b552c0fc47d..a8d6af27803a 100644
> --- a/tools/testing/selftests/bpf/test_maps.c
> +++ b/tools/testing/selftests/bpf/test_maps.c
> @@ -257,23 +257,35 @@ static void test_hashmap_percpu(int task, void *data)
> close(fd);
> }
>
> +static int helper_fill_hashmap(int max_entries)
How about we add map_flags as the second argument of this function?
This will help
avoid the old_flags hack.
Thanks,
Song
> +{
> + int i, fd, ret;
> + long long key, value;
> +
> + fd = bpf_create_map(BPF_MAP_TYPE_HASH, sizeof(key), sizeof(value),
> + max_entries, map_flags);
> + CHECK(fd < 0,
> + "failed to create hashmap",
> + "err: %s, flags: 0x%x\n", strerror(errno), map_flags);
> +
> + for (i = 0; i < max_entries; i++) {
> + key = i; value = key;
> + ret = bpf_map_update_elem(fd, &key, &value, BPF_NOEXIST);
> + CHECK(ret != 0,
> + "can't update hashmap",
> + "err: %s\n", strerror(ret));
> + }
> +
> + return fd;
> +}
> +
> static void test_hashmap_walk(int task, void *data)
> {
> int fd, i, max_entries = 1000;
> long long key, value, next_key;
> bool next_key_valid = true;
>
> - fd = bpf_create_map(BPF_MAP_TYPE_HASH, sizeof(key), sizeof(value),
> - max_entries, map_flags);
> - if (fd < 0) {
> - printf("Failed to create hashmap '%s'!\n", strerror(errno));
> - exit(1);
> - }
> -
> - for (i = 0; i < max_entries; i++) {
> - key = i; value = key;
> - assert(bpf_map_update_elem(fd, &key, &value, BPF_NOEXIST) == 0);
> - }
> + fd = helper_fill_hashmap(max_entries);
>
> for (i = 0; bpf_map_get_next_key(fd, !i ? NULL : &key,
> &next_key) == 0; i++) {
> @@ -305,6 +317,39 @@ static void test_hashmap_walk(int task, void *data)
> close(fd);
> }
>
> +static void test_hashmap_zero_seed(void)
> +{
> + int i, first, second, old_flags;
> + long long key, next_first, next_second;
> +
> + old_flags = map_flags;
> + map_flags |= BPF_F_ZERO_SEED;
> +
> + first = helper_fill_hashmap(3);
> + second = helper_fill_hashmap(3);
> +
> + for (i = 0; ; i++) {
> + void *key_ptr = !i ? NULL : &key;
> +
> + if (bpf_map_get_next_key(first, key_ptr, &next_first) != 0)
> + break;
> +
> + CHECK(bpf_map_get_next_key(second, key_ptr, &next_second) != 0,
> + "next_key for second map must succeed",
> + "key_ptr: %p", key_ptr);
> + CHECK(next_first != next_second,
> + "keys must match",
> + "i: %d first: %lld second: %lld\n", i,
> + next_first, next_second);
> +
> + key = next_first;
> + }
> +
> + map_flags = old_flags;
> + close(first);
> + close(second);
> +}
> +
> static void test_arraymap(int task, void *data)
> {
> int key, next_key, fd;
> @@ -1417,6 +1462,7 @@ static void run_all_tests(void)
> test_hashmap(0, NULL);
> test_hashmap_percpu(0, NULL);
> test_hashmap_walk(0, NULL);
> + test_hashmap_zero_seed();
>
> test_arraymap(0, NULL);
> test_arraymap_percpu(0, NULL);
> --
> 2.17.1
>
