openkylin
/
linux
mirror of https://gitee.com/openkylin/linux.git
9
0
Fork 0
Code Issues Projects Releases Wiki Activity

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
This commit is contained in:
Quentin Monnet 2020-09-10 11:26:51 +01:00 committed by Alexei Starovoitov
parent a20693b6e7
commit 86233ce35e
1 changed files with 2 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
tools/bpf/bpftool/map.c
View File

@ -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) {