diff options
| author | David Ahern <dsahern@gmail.com> | 2018-11-08 22:00:07 +0100 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2018-11-09 10:03:59 +0100 |
| commit | bf598a8f0f771302d4ecb0ef0003c54732221597 (patch) | |
| tree | 39da7a18141381033f339f182a7255814a161497 | |
| parent | selftests/bpf: add a test case for sock_ops perf-event notification (diff) | |
| download | linux-bf598a8f0f771302d4ecb0ef0003c54732221597.tar.xz linux-bf598a8f0f771302d4ecb0ef0003c54732221597.zip | |
bpftool: Improve handling of ENOENT on map dumps
bpftool output is not user friendly when dumping a map with only a few
populated entries:
$ bpftool map
1: devmap name tx_devmap flags 0x0
key 4B value 4B max_entries 64 memlock 4096B
2: array name tx_idxmap flags 0x0
key 4B value 4B max_entries 64 memlock 4096B
$ bpftool map dump id 1
key:
00 00 00 00
value:
No such file or directory
key:
01 00 00 00
value:
No such file or directory
key:
02 00 00 00
value:
No such file or directory
key: 03 00 00 00 value: 03 00 00 00
Handle ENOENT by keeping the line format sane and dumping
"<no entry>" for the value
$ bpftool map dump id 1
key: 00 00 00 00 value: <no entry>
key: 01 00 00 00 value: <no entry>
key: 02 00 00 00 value: <no entry>
key: 03 00 00 00 value: 03 00 00 00
...
Signed-off-by: David Ahern <dsahern@gmail.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| -rw-r--r-- | tools/bpf/bpftool/map.c | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c index 101b8a881225..dc9a8967ab8c 100644 --- a/tools/bpf/bpftool/map.c +++ b/tools/bpf/bpftool/map.c @@ -383,7 +383,10 @@ static void print_entry_plain(struct bpf_map_info *info, unsigned char *key, printf(single_line ? " " : "\n"); printf("value:%c", break_names ? '\n' : ' '); - fprint_hex(stdout, value, info->value_size, " "); + if (value) + fprint_hex(stdout, value, info->value_size, " "); + else + printf("<no entry>"); printf("\n"); } else { @@ -398,8 +401,11 @@ static void print_entry_plain(struct bpf_map_info *info, unsigned char *key, for (i = 0; i < n; i++) { printf("value (CPU %02d):%c", i, info->value_size > 16 ? '\n' : ' '); - fprint_hex(stdout, value + i * step, - info->value_size, " "); + if (value) + fprint_hex(stdout, value + i * step, + info->value_size, " "); + else + printf("<no entry>"); printf("\n"); } } @@ -731,7 +737,11 @@ static int dump_map_elem(int fd, void *key, void *value, jsonw_string_field(json_wtr, "error", strerror(lookup_errno)); jsonw_end_object(json_wtr); } else { - print_entry_error(map_info, key, strerror(lookup_errno)); + if (errno == ENOENT) + print_entry_plain(map_info, key, NULL); + else + print_entry_error(map_info, key, + strerror(lookup_errno)); } return 0; |