Commit 86233ce3 authored Sep 10, 2020 by Quentin Monnet Committed by Alexei Starovoitov Sep 10, 2020

tools: bpftool: Keep errors for map-of-map dumps if distinct from ENOENT



When dumping outer maps or prog_array maps, and on lookup failure,
bpftool simply skips the entry with no error message. This is because
the kernel returns non-zero when no value is found for the provided key,
which frequently happen for those maps if they have not been filled.

When such a case occurs, errno is set to ENOENT. It seems unlikely we
could receive other error codes at this stage (we successfully retrieved
map info just before), but to be on the safe side, let's skip the entry
only if errno was ENOENT, and not for the other errors.

v3: New patch

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200910102652.10509-3-quentin@isovalent.com

parent a20693b6

tools/bpf/bpftool/map.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -240,8 +240,8 @@ print_entry_error(struct bpf_map_info map_info, void key, int lookup_errno)
		* means there is no entry for that key. Do not print an error message
		* in that case.
		*/
		if (map_is_map_of_maps(map_info->type) \|\|
		map_is_map_of_progs(map_info->type))
		if ((map_is_map_of_maps(map_info->type) \|\|
		map_is_map_of_progs(map_info->type)) && lookup_errno == ENOENT)
		return;

		if (json_output) {

Admin message