On 10/09/2020 17:42, Andrii Nakryiko wrote: > On Thu, Sep 10, 2020 at 3:27 AM Quentin Monnet <quentin@xxxxxxxxxxxxx> wrote: >> >> 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@xxxxxxxxxxxxx> >> --- >> 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; > > > Ah, ok, you decided to split it out into a separate patch. Ok. Yes, I chose to keep the first one with no functional change to keep the logs cleaner. > Acked-by: Andrii Nakryiko <andriin@xxxxxx> Thanks! Quentin
