| Message ID | 20201003085505.3388332-3-liuhangbin@gmail.com |
|---|---|
| State | Changes Requested |
| Delegated to: | BPF Maintainers |
| Headers | show |
| Series | Fix pining maps after reuse map fd | expand |
On Sat, Oct 3, 2020 at 1:55 AM Hangbin Liu <liuhangbin@gmail.com> wrote: > > Say a user reuse map fd after creating a map manually and set the > pin_path, then load the object via libbpf. > > In libbpf bpf_object__create_maps(), bpf_object__reuse_map() will > return 0 if there is no pinned map in map->pin_path. Then after > checking if map fd exist, we should also check if pin_path was set > and do bpf_map__pin() instead of continue the loop. > > Fix it by creating map if fd not exist and continue checking pin_path > after that. > > v2: keep if condition with existing order > > Suggested-by: Andrii Nakryiko <andrii.nakryiko@gmail.com> > Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> > --- Acked-by: Andrii Nakryiko <andrii@kernel.org> > tools/lib/bpf/libbpf.c | 37 ++++++++++++++++++------------------- > 1 file changed, 18 insertions(+), 19 deletions(-) > [...]
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index c8b5fe45682d..1fb3fd733b23 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -4245,29 +4245,28 @@ bpf_object__create_maps(struct bpf_object *obj) if (map->fd >= 0) { pr_debug("map '%s': skipping creation (preset fd=%d)\n", map->name, map->fd); - continue; - } - - err = bpf_object__create_map(obj, map); - if (err) - goto err_out; + } else { + err = bpf_object__create_map(obj, map); + if (err) + goto err_out; - pr_debug("map '%s': created successfully, fd=%d\n", map->name, - map->fd); + pr_debug("map '%s': created successfully, fd=%d\n", + map->name, map->fd); - if (bpf_map__is_internal(map)) { - err = bpf_object__populate_internal_map(obj, map); - if (err < 0) { - zclose(map->fd); - goto err_out; + if (bpf_map__is_internal(map)) { + err = bpf_object__populate_internal_map(obj, map); + if (err < 0) { + zclose(map->fd); + goto err_out; + } } - } - if (map->init_slots_sz) { - err = init_map_slots(map); - if (err < 0) { - zclose(map->fd); - goto err_out; + if (map->init_slots_sz) { + err = init_map_slots(map); + if (err < 0) { + zclose(map->fd); + goto err_out; + } } }
Say a user reuse map fd after creating a map manually and set the pin_path, then load the object via libbpf. In libbpf bpf_object__create_maps(), bpf_object__reuse_map() will return 0 if there is no pinned map in map->pin_path. Then after checking if map fd exist, we should also check if pin_path was set and do bpf_map__pin() instead of continue the loop. Fix it by creating map if fd not exist and continue checking pin_path after that. v2: keep if condition with existing order Suggested-by: Andrii Nakryiko <andrii.nakryiko@gmail.com> Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> --- tools/lib/bpf/libbpf.c | 37 ++++++++++++++++++------------------- 1 file changed, 18 insertions(+), 19 deletions(-)