the bpf_map_update_elem in xdpdump_user.c crashes when key is more than 127

[souradeep100]

The the number of cpus are more than 127, then it hits assert, and upon checking we can see it is hitting following error:
If the key is 128 or more then the bpf syscall is failing.
bpf(BPF_MAP_UPDATE_ELEM, {map_fd=3, key=0x7fffae9f9478, value=0x7fffae9f9474, flags=BPF_ANY}, 72) = -1 E2BIG (Argument list too long)

I have verified the same key value works using linux bpf self test test_maps.

test_hashmap(unsigned int task, void *data)
  38 {
  39         long long key, next_key, first_key, value;
  40         int fd;
  41
  42         fd = bpf_create_map(BPF_MAP_TYPE_HASH, sizeof(key), sizeof(value),
  43                             2, map_flags);
  44         if (fd < 0) {
  45                 printf("Failed to create hashmap '%s'!\n", strerror(errno));
  46                 exit(1);
  47         }
  48
  49         key = 128;
  50         value = 1234;
  51         /* Insert key=1 element. */
  52         printf("insert key 128 and value 1234\n");
  53         assert(bpf_map_update_elem(fd, &key, &value, BPF_ANY) == 0);
  54         printf("no assert\n");