Commit bf598a8f0f77 ("bpftool: Improve handling of ENOENT on map dumps")
used print_entry_plain() in case of ENOENT because that function provided
the desired formatting. However, that commit actually introduces dead code.
Per-cpu maps are zero-filled. When reading them, it's all or nothing. There
will never be a case where some cpus have an entry and others don't.
The truth is that ENOENT is an error case. So rework print_entry_error() to
provide the desired formatting.
Note that this commit changes the output format in case of errors other
than ENOENT.
example before:
key:
00 00 00 00
value:
No space left on device
[...]
example after:
key: 00 00 00 00
value:
No space left on device
[...]
The ENOENT case is unchanged:
key: 00 00 00 00 value: 14 5b 00 00 00 00 00 00
key: 01 00 00 00 value: <no entry>
[...]
Signed-off-by: Benjamin Poirier <bpoir...@suse.com>
---
tools/bpf/bpftool/map.c | 34 ++++++++++++++--------------------
1 file changed, 14 insertions(+), 20 deletions(-)
diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c
index e96903078991..71840faaeab5 100644
--- a/tools/bpf/bpftool/map.c
+++ b/tools/bpf/bpftool/map.c
@@ -261,20 +261,19 @@ static void print_entry_json(struct bpf_map_info *info,
unsigned char *key,
}
static void print_entry_error(struct bpf_map_info *info, unsigned char *key,
- const char *value)
+ const char *value, bool single_line)
{
- int value_size = strlen(value);
- bool single_line, break_names;
+ bool break_names;
- break_names = info->key_size > 16 || value_size > 16;
- single_line = info->key_size + value_size <= 24 && !break_names;
+ break_names = info->key_size > 16;
+ single_line = single_line && !break_names;
printf("key:%c", break_names ? '\n' : ' ');
fprint_hex(stdout, key, info->key_size, " ");
printf(single_line ? " " : "\n");
- printf("value:%c%s", break_names ? '\n' : ' ', value);
+ printf("value:%c%s", single_line ? ' ' : '\n', value);
printf("\n");
}
@@ -298,11 +297,7 @@ static void print_entry_plain(struct bpf_map_info *info,
unsigned char *key,
if (info->value_size) {
printf("value:%c", break_names ? '\n' : ' ');
- if (value)
- fprint_hex(stdout, value, info->value_size,
- " ");
- else
- printf("<no entry>");
+ fprint_hex(stdout, value, info->value_size, " ");
}
printf("\n");
@@ -321,11 +316,8 @@ 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' : ' ');
- if (value)
- fprint_hex(stdout, value + i * step,
- info->value_size, " ");
- else
- printf("<no entry>");
+ fprint_hex(stdout, value + i * step,
+ info->value_size, " ");
printf("\n");
}
}
@@ -722,11 +714,13 @@ 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 {
+ const char *msg = NULL;
+
if (errno == ENOENT)
- print_entry_plain(map_info, key, NULL);
- else
- print_entry_error(map_info, key,
- strerror(lookup_errno));
+ msg = "<no entry>";
+
+ print_entry_error(map_info, key,
+ msg ? : strerror(lookup_errno), !!msg);
}
return 0;
--
2.21.0
