From 86233ce35e4b886dc5998c72ec6158ed72150782 Mon Sep 17 00:00:00 2001 From: Quentin Monnet Date: Thu, 10 Sep 2020 11:26:51 +0100 Subject: [PATCH] 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 Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20200910102652.10509-3-quentin@isovalent.com --- tools/bpf/bpftool/map.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c index c8159cb4fb1e..d8581d5e98a1 100644 --- a/tools/bpf/bpftool/map.c +++ b/tools/bpf/bpftool/map.c @@ -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) {