Commit bf598a8f0f77 ("bpftool: Improve handling of ENOENT on map dumps")
used print_entry_plain() in case of ENOENT. However, that commit 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. Use print_entry_error() to
output the desired message. That function's "value" parameter is also
renamed to indicate that we never use it for an actual map value.
The output format is unchanged.
Signed-off-by: Benjamin Poirier <bpoirier@xxxxxxxx>
---
tools/bpf/bpftool/map.c | 33 ++++++++++++++-------------------
1 file changed, 14 insertions(+), 19 deletions(-)
diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c
index e96903078991..df958af56b6c 100644
--- a/tools/bpf/bpftool/map.c
+++ b/tools/bpf/bpftool/map.c
@@ -261,20 +261,20 @@ 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 *error_msg)
{
- int value_size = strlen(value);
+ int msg_size = strlen(error_msg);
bool single_line, 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 || msg_size > 16;
+ single_line = info->key_size + msg_size <= 24 && !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", break_names ? '\n' : ' ', error_msg);
printf("\n");
}
@@ -298,11 +298,7 @@ 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 +317,8 @@ 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 +715,13 @@ 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));
