From 0478c3bf812451315da6eeb79f8cf151db094767 Mon Sep 17 00:00:00 2001 From: Benjamin Poirier Date: Mon, 15 Apr 2019 16:15:35 +0900 Subject: bpftool: Use print_entry_error() in case of ENOENT when dumping 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 Reviewed-by: Quentin Monnet Reviewed-by: Jakub Kicinski Signed-off-by: Daniel Borkmann --- tools/bpf/bpftool/map.c | 33 ++++++++++++++------------------- 1 file changed, 14 insertions(+), 19 deletions(-) (limited to 'tools/bpf') 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(""); + 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(""); + 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 = ""; + + print_entry_error(map_info, key, + msg ? : strerror(lookup_errno)); } return 0; -- cgit v1.2.3-59-g8ed1b