On 7/16/21 7:27 AM, Andrii Nakryiko wrote:
On Wed, Jul 14, 2021 at 9:52 AM Martynas Pumputis <m@xxxxxxxxx> wrote:If creating an outer map of a BTF-defined map-in-map fails (via bpf_object__create_map()), then the previously created its inner map won't be destroyed. Fix this by ensuring that the destroy routines are not bypassed in the case of a failure. Fixes: 646f02ffdd49c ("libbpf: Add BTF-defined map-in-map support") Reported-by: Andrii Nakryiko <andrii@xxxxxxxxxx> Signed-off-by: Martynas Pumputis <m@xxxxxxxxx> --- tools/lib/bpf/libbpf.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 6f5e2757bb3c..1a840e81ea0a 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -4479,6 +4479,7 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, b { struct bpf_create_map_attr create_attr; struct bpf_map_def *def = &map->def; + int ret = 0; memset(&create_attr, 0, sizeof(create_attr)); @@ -4561,7 +4562,7 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, b } if (map->fd < 0) - return -errno; + ret = -errno;Oh, isn't this a complicated function, eh? I stared at the code for a while until I understood the whole idea with map->inner_map handling there. I think your change is correct, I'd just love you to consolidate all those "int err" definitions, and use just one throughout this function. It will clean up two other if() blocks, and in this case "err" name is more appropriate, because it always is <= 0.
Good idea. I will send v2 once we have agreed on the selftesting issue.
if (bpf_map_type__is_map_in_map(def->type) && map->inner_map) { if (obj->gen_loader) @@ -4570,7 +4571,7 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, b zfree(&map->inner_map); } - return 0; + return ret; } static int init_map_slots(struct bpf_object *obj, struct bpf_map *map) -- 2.32.0
