samples/bpf: make map creation more verbose

map creation is typically the first one to fail when rlimits are
too low, not enough memory, etc
Make this failure scenario more verbose

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 1 deletions

diff --git a/samples/bpf/bpf_load.c b/samples/bpf/bpf_load.c
index da86a8e0a95a..816bca5760a0 100644
--- a/samples/bpf/bpf_load.c
+++ b/samples/bpf/bpf_load.c
@@ -158,8 +158,11 @@ static int load_maps(struct bpf_map_def *maps, int len)
                                            maps[i].key_size,
                                            maps[i].value_size,
                                            maps[i].max_entries);
-                if (map_fd[i] < 0)
+                if (map_fd[i] < 0) {
+                        printf("failed to create a map: %d %s\n",
+                               errno, strerror(errno));
                         return 1;
+                }
 
                 if (maps[i].type == BPF_MAP_TYPE_PROG_ARRAY)
                         prog_array_fd = map_fd[i];