diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c index e7113d700b87..025d7e2214ae 100644 --- a/kernel/bpf/cgroup.c +++ b/kernel/bpf/cgroup.c @@ -24,6 +24,23 @@ DEFINE_STATIC_KEY_ARRAY_FALSE(cgroup_bpf_enabled_key, MAX_CGROUP_BPF_ATTACH_TYPE); EXPORT_SYMBOL(cgroup_bpf_enabled_key); +/* + * cgroup bpf destruction makes heavy use of work items and there can be a lot + * of concurrent destructions. Use a separate workqueue so that cgroup bpf + * destruction work items don't end up filling up max_active of system_wq + * which may lead to deadlock. + */ +static struct workqueue_struct *cgroup_bpf_destroy_wq; + +static int __init cgroup_bpf_wq_init(void) +{ + cgroup_bpf_destroy_wq = alloc_workqueue("cgroup_bpf_destroy", 0, 1); + if (!cgroup_bpf_destroy_wq) + panic("Failed to alloc workqueue for cgroup bpf destroy.\n"); + return 0; +} +core_initcall(cgroup_bpf_wq_init); + /* __always_inline is necessary to prevent indirect call through run_prog * function pointer. */ @@ -334,7 +351,7 @@ static void cgroup_bpf_release_fn(struct percpu_ref *ref) struct cgroup *cgrp = container_of(ref, struct cgroup, bpf.refcnt); INIT_WORK(&cgrp->bpf.release_work, cgroup_bpf_release); - queue_work(system_wq, &cgrp->bpf.release_work); + queue_work(cgroup_bpf_destroy_wq, &cgrp->bpf.release_work); } /* Get underlying bpf_prog of bpf_prog_list entry, regardless if it's through diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 5886b95c6eae..044c7ba1cc48 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -5789,7 +5789,7 @@ static bool cgroup_check_hierarchy_limits(struct cgroup *parent) { struct cgroup *cgroup; int ret = false; - int level = 1; + int level = 0; lockdep_assert_held(&cgroup_mutex); @@ -5797,7 +5797,7 @@ static bool cgroup_check_hierarchy_limits(struct cgroup *parent) if (cgroup->nr_descendants >= cgroup->max_descendants) goto fail; - if (level > cgroup->max_depth) + if (level >= cgroup->max_depth) goto fail; level++;