4.20-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit bf598a8f0f771302d4ecb0ef0003c54732221597 ]
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 Signed-off-by: Sasha Levin sashal@kernel.org --- tools/bpf/bpftool/map.c | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-)
diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c index 7bf38f0e152e..9988d5c126b6 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;