diff options
| -rw-r--r-- | include/linux/bpf-cgroup.h | 2 | ||||
| -rw-r--r-- | kernel/bpf/cgroup.c | 28 |
2 files changed, 18 insertions, 12 deletions
diff --git a/include/linux/bpf-cgroup.h b/include/linux/bpf-cgroup.h index 9f100fc422c3..b631ee75762d 100644 --- a/include/linux/bpf-cgroup.h +++ b/include/linux/bpf-cgroup.h @@ -72,7 +72,7 @@ struct cgroup_bpf { u32 flags[MAX_BPF_ATTACH_TYPE]; /* temp storage for effective prog array used by prog_attach/detach */ - struct bpf_prog_array __rcu *inactive; + struct bpf_prog_array *inactive; /* reference counter used to detach bpf programs after cgroup removal */ struct percpu_ref refcnt; diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c index d995edbe816d..ff594eb86fd7 100644 --- a/kernel/bpf/cgroup.c +++ b/kernel/bpf/cgroup.c @@ -38,6 +38,7 @@ static void cgroup_bpf_release(struct work_struct *work) struct cgroup *cgrp = container_of(work, struct cgroup, bpf.release_work); enum bpf_cgroup_storage_type stype; + struct bpf_prog_array *old_array; unsigned int type; for (type = 0; type < ARRAY_SIZE(cgrp->bpf.progs); type++) { @@ -54,7 +55,10 @@ static void cgroup_bpf_release(struct work_struct *work) kfree(pl); static_branch_dec(&cgroup_bpf_enabled_key); } - bpf_prog_array_free(cgrp->bpf.effective[type]); + old_array = rcu_dereference_protected( + cgrp->bpf.effective[type], + percpu_ref_is_dying(&cgrp->bpf.refcnt)); + bpf_prog_array_free(old_array); } percpu_ref_exit(&cgrp->bpf.refcnt); @@ -126,7 +130,7 @@ static bool hierarchy_allows_attach(struct cgroup *cgrp, */ static int compute_effective_progs(struct cgroup *cgrp, enum bpf_attach_type type, - struct bpf_prog_array __rcu **array) + struct bpf_prog_array **array) { enum bpf_cgroup_storage_type stype; struct bpf_prog_array *progs; @@ -164,17 +168,16 @@ static int compute_effective_progs(struct cgroup *cgrp, } } while ((p = cgroup_parent(p))); - rcu_assign_pointer(*array, progs); + *array = progs; return 0; } static void activate_effective_progs(struct cgroup *cgrp, enum bpf_attach_type type, - struct bpf_prog_array __rcu *array) + struct bpf_prog_array *old_array) { - struct bpf_prog_array __rcu *old_array; - - old_array = xchg(&cgrp->bpf.effective[type], array); + rcu_swap_protected(cgrp->bpf.effective[type], old_array, + lockdep_is_held(&cgroup_mutex)); /* free prog array after grace period, since __cgroup_bpf_run_*() * might be still walking the array */ @@ -191,7 +194,7 @@ int cgroup_bpf_inherit(struct cgroup *cgrp) * that array below is variable length */ #define NR ARRAY_SIZE(cgrp->bpf.effective) - struct bpf_prog_array __rcu *arrays[NR] = {}; + struct bpf_prog_array *arrays[NR] = {}; int ret, i; ret = percpu_ref_init(&cgrp->bpf.refcnt, cgroup_bpf_release_fn, 0, @@ -477,10 +480,14 @@ int __cgroup_bpf_query(struct cgroup *cgrp, const union bpf_attr *attr, enum bpf_attach_type type = attr->query.attach_type; struct list_head *progs = &cgrp->bpf.progs[type]; u32 flags = cgrp->bpf.flags[type]; + struct bpf_prog_array *effective; int cnt, ret = 0, i; + effective = rcu_dereference_protected(cgrp->bpf.effective[type], + lockdep_is_held(&cgroup_mutex)); + if (attr->query.query_flags & BPF_F_QUERY_EFFECTIVE) - cnt = bpf_prog_array_length(cgrp->bpf.effective[type]); + cnt = bpf_prog_array_length(effective); else cnt = prog_list_length(progs); @@ -497,8 +504,7 @@ int __cgroup_bpf_query(struct cgroup *cgrp, const union bpf_attr *attr, } if (attr->query.query_flags & BPF_F_QUERY_EFFECTIVE) { - return bpf_prog_array_copy_to_user(cgrp->bpf.effective[type], - prog_ids, cnt); + return bpf_prog_array_copy_to_user(effective, prog_ids, cnt); } else { struct bpf_prog_list *pl; u32 id; |