Failure to update a bpf_link because it has been auto-detached by a dying
cgroup currently results in EINVAL error, even though the arguments passed
to bpf() syscall are not wrong.
bpf_links attaching to netns in this case will return ENOLINK, which
carries the message that the link is no longer attached to anything.
Change cgroup bpf_links to do the same to keep the uAPI errors consistent.
Fixes: 0c991ebc8c69 ("bpf: Implement bpf_prog replacement for an active bpf_cgroup_link")
Suggested-by: Lorenz Bauer <lmb@xxxxxxxxxxxxxx>
Signed-off-by: Jakub Sitnicki <jakub@xxxxxxxxxxxxxx>
---
kernel/bpf/cgroup.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
index 5c0e964105ac..fdf7836750a3 100644
--- a/kernel/bpf/cgroup.c
+++ b/kernel/bpf/cgroup.c
@@ -595,7 +595,7 @@ static int cgroup_bpf_replace(struct bpf_link *link, struct bpf_prog *new_prog,
mutex_lock(&cgroup_mutex);
/* link might have been auto-released by dying cgroup, so fail */
if (!cg_link->cgroup) {
- ret = -EINVAL;
+ ret = -ENOLINK;
goto out_unlock;
}
if (old_prog && link->prog != old_prog) {
--
2.25.4
