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Commit 0478c3bf authored by Benjamin Poirier's avatar Benjamin Poirier Committed by Daniel Borkmann
Browse files

bpftool: Use print_entry_error() in case of ENOENT when dumping 



Commit bf598a8f ("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: default avatarBenjamin Poirier <bpoirier@suse.com>
Reviewed-by: default avatarQuentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: default avatarJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
parent 25df480d

tools/bpf/bpftool/map.c

+14 −19
Original line number Diff line number Diff line
@@ -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>");

				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

			msg = "<no entry>";



		print_entry_error(map_info, key,

					  strerror(lookup_errno));

				  msg ? : strerror(lookup_errno));

	}



	return 0;