From: Martynas Pumputis m@lambda.lt
[ Upstream commit a21ab4c59e09c2a9994a6e393b7484e3b3f78a99 ]
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@kernel.org Signed-off-by: Martynas Pumputis m@lambda.lt Signed-off-by: Andrii Nakryiko andrii@kernel.org Acked-by: John Fastabend john.fastabend@gmail.com Link: https://lore.kernel.org/bpf/20210719173838.423148-2-m@lambda.lt Signed-off-by: Sasha Levin sashal@kernel.org --- tools/lib/bpf/libbpf.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 2af2d0e4a231..f6ebda75b030 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -4409,6 +4409,7 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map) { struct bpf_create_map_attr create_attr; struct bpf_map_def *def = &map->def; + int err = 0;
memset(&create_attr, 0, sizeof(create_attr));
@@ -4451,8 +4452,6 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map)
if (bpf_map_type__is_map_in_map(def->type)) { if (map->inner_map) { - int err; - err = bpf_object__create_map(obj, map->inner_map); if (err) { pr_warn("map '%s': failed to create inner map: %d\n", @@ -4469,8 +4468,8 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map) if (map->fd < 0 && (create_attr.btf_key_type_id || create_attr.btf_value_type_id)) { char *cp, errmsg[STRERR_BUFSIZE]; - int err = -errno;
+ err = -errno; cp = libbpf_strerror_r(err, errmsg, sizeof(errmsg)); pr_warn("Error in bpf_create_map_xattr(%s):%s(%d). Retrying without BTF.\n", map->name, cp, err); @@ -4482,15 +4481,14 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map) map->fd = bpf_create_map_xattr(&create_attr); }
- if (map->fd < 0) - return -errno; + err = map->fd < 0 ? -errno : 0;
if (bpf_map_type__is_map_in_map(def->type) && map->inner_map) { bpf_map__destroy(map->inner_map); zfree(&map->inner_map); }
- return 0; + return err; }
static int init_map_slots(struct bpf_map *map)