diff options
Diffstat (limited to 'kernel/bpf/cgroup.c')
-rw-r--r-- | kernel/bpf/cgroup.c | 162 |
1 files changed, 92 insertions, 70 deletions
diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c index 3d83ee7df381..6a7d931bbc55 100644 --- a/kernel/bpf/cgroup.c +++ b/kernel/bpf/cgroup.c @@ -34,6 +34,8 @@ void cgroup_bpf_put(struct cgroup *cgrp) list_for_each_entry_safe(pl, tmp, progs, node) { list_del(&pl->node); bpf_prog_put(pl->prog); + bpf_cgroup_storage_unlink(pl->storage); + bpf_cgroup_storage_free(pl->storage); kfree(pl); static_branch_dec(&cgroup_bpf_enabled_key); } @@ -95,7 +97,7 @@ static int compute_effective_progs(struct cgroup *cgrp, enum bpf_attach_type type, struct bpf_prog_array __rcu **array) { - struct bpf_prog_array __rcu *progs; + struct bpf_prog_array *progs; struct bpf_prog_list *pl; struct cgroup *p = cgrp; int cnt = 0; @@ -115,18 +117,20 @@ static int compute_effective_progs(struct cgroup *cgrp, cnt = 0; p = cgrp; do { - if (cnt == 0 || (p->bpf.flags[type] & BPF_F_ALLOW_MULTI)) - list_for_each_entry(pl, - &p->bpf.progs[type], node) { - if (!pl->prog) - continue; - rcu_dereference_protected(progs, 1)-> - progs[cnt++] = pl->prog; - } - p = cgroup_parent(p); - } while (p); + if (cnt > 0 && !(p->bpf.flags[type] & BPF_F_ALLOW_MULTI)) + continue; + + list_for_each_entry(pl, &p->bpf.progs[type], node) { + if (!pl->prog) + continue; - *array = progs; + progs->items[cnt].prog = pl->prog; + progs->items[cnt].cgroup_storage = pl->storage; + cnt++; + } + } while ((p = cgroup_parent(p))); + + rcu_assign_pointer(*array, progs); return 0; } @@ -173,6 +177,45 @@ cleanup: return -ENOMEM; } +static int update_effective_progs(struct cgroup *cgrp, + enum bpf_attach_type type) +{ + struct cgroup_subsys_state *css; + int err; + + /* allocate and recompute effective prog arrays */ + css_for_each_descendant_pre(css, &cgrp->self) { + struct cgroup *desc = container_of(css, struct cgroup, self); + + err = compute_effective_progs(desc, type, &desc->bpf.inactive); + if (err) + goto cleanup; + } + + /* all allocations were successful. Activate all prog arrays */ + css_for_each_descendant_pre(css, &cgrp->self) { + struct cgroup *desc = container_of(css, struct cgroup, self); + + activate_effective_progs(desc, type, desc->bpf.inactive); + desc->bpf.inactive = NULL; + } + + return 0; + +cleanup: + /* oom while computing effective. Free all computed effective arrays + * since they were not activated + */ + css_for_each_descendant_pre(css, &cgrp->self) { + struct cgroup *desc = container_of(css, struct cgroup, self); + + bpf_prog_array_free(desc->bpf.inactive); + desc->bpf.inactive = NULL; + } + + return err; +} + #define BPF_CGROUP_MAX_PROGS 64 /** @@ -189,7 +232,7 @@ int __cgroup_bpf_attach(struct cgroup *cgrp, struct bpf_prog *prog, { struct list_head *progs = &cgrp->bpf.progs[type]; struct bpf_prog *old_prog = NULL; - struct cgroup_subsys_state *css; + struct bpf_cgroup_storage *storage, *old_storage = NULL; struct bpf_prog_list *pl; bool pl_was_allocated; int err; @@ -211,72 +254,71 @@ int __cgroup_bpf_attach(struct cgroup *cgrp, struct bpf_prog *prog, if (prog_list_length(progs) >= BPF_CGROUP_MAX_PROGS) return -E2BIG; + storage = bpf_cgroup_storage_alloc(prog); + if (IS_ERR(storage)) + return -ENOMEM; + if (flags & BPF_F_ALLOW_MULTI) { - list_for_each_entry(pl, progs, node) - if (pl->prog == prog) + list_for_each_entry(pl, progs, node) { + if (pl->prog == prog) { /* disallow attaching the same prog twice */ + bpf_cgroup_storage_free(storage); return -EINVAL; + } + } pl = kmalloc(sizeof(*pl), GFP_KERNEL); - if (!pl) + if (!pl) { + bpf_cgroup_storage_free(storage); return -ENOMEM; + } + pl_was_allocated = true; pl->prog = prog; + pl->storage = storage; list_add_tail(&pl->node, progs); } else { if (list_empty(progs)) { pl = kmalloc(sizeof(*pl), GFP_KERNEL); - if (!pl) + if (!pl) { + bpf_cgroup_storage_free(storage); return -ENOMEM; + } pl_was_allocated = true; list_add_tail(&pl->node, progs); } else { pl = list_first_entry(progs, typeof(*pl), node); old_prog = pl->prog; + old_storage = pl->storage; + bpf_cgroup_storage_unlink(old_storage); pl_was_allocated = false; } pl->prog = prog; + pl->storage = storage; } cgrp->bpf.flags[type] = flags; - /* allocate and recompute effective prog arrays */ - css_for_each_descendant_pre(css, &cgrp->self) { - struct cgroup *desc = container_of(css, struct cgroup, self); - - err = compute_effective_progs(desc, type, &desc->bpf.inactive); - if (err) - goto cleanup; - } - - /* all allocations were successful. Activate all prog arrays */ - css_for_each_descendant_pre(css, &cgrp->self) { - struct cgroup *desc = container_of(css, struct cgroup, self); - - activate_effective_progs(desc, type, desc->bpf.inactive); - desc->bpf.inactive = NULL; - } + err = update_effective_progs(cgrp, type); + if (err) + goto cleanup; static_branch_inc(&cgroup_bpf_enabled_key); + if (old_storage) + bpf_cgroup_storage_free(old_storage); if (old_prog) { bpf_prog_put(old_prog); static_branch_dec(&cgroup_bpf_enabled_key); } + bpf_cgroup_storage_link(storage, cgrp, type); return 0; cleanup: - /* oom while computing effective. Free all computed effective arrays - * since they were not activated - */ - css_for_each_descendant_pre(css, &cgrp->self) { - struct cgroup *desc = container_of(css, struct cgroup, self); - - bpf_prog_array_free(desc->bpf.inactive); - desc->bpf.inactive = NULL; - } - /* and cleanup the prog list */ pl->prog = old_prog; + bpf_cgroup_storage_free(pl->storage); + pl->storage = old_storage; + bpf_cgroup_storage_link(old_storage, cgrp, type); if (pl_was_allocated) { list_del(&pl->node); kfree(pl); @@ -299,7 +341,6 @@ int __cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog, struct list_head *progs = &cgrp->bpf.progs[type]; u32 flags = cgrp->bpf.flags[type]; struct bpf_prog *old_prog = NULL; - struct cgroup_subsys_state *css; struct bpf_prog_list *pl; int err; @@ -338,25 +379,14 @@ int __cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog, pl->prog = NULL; } - /* allocate and recompute effective prog arrays */ - css_for_each_descendant_pre(css, &cgrp->self) { - struct cgroup *desc = container_of(css, struct cgroup, self); - - err = compute_effective_progs(desc, type, &desc->bpf.inactive); - if (err) - goto cleanup; - } - - /* all allocations were successful. Activate all prog arrays */ - css_for_each_descendant_pre(css, &cgrp->self) { - struct cgroup *desc = container_of(css, struct cgroup, self); - - activate_effective_progs(desc, type, desc->bpf.inactive); - desc->bpf.inactive = NULL; - } + err = update_effective_progs(cgrp, type); + if (err) + goto cleanup; /* now can actually delete it from this cgroup list */ list_del(&pl->node); + bpf_cgroup_storage_unlink(pl->storage); + bpf_cgroup_storage_free(pl->storage); kfree(pl); if (list_empty(progs)) /* last program was detached, reset flags to zero */ @@ -367,16 +397,6 @@ int __cgroup_bpf_detach(struct cgroup *cgrp, struct bpf_prog *prog, return 0; cleanup: - /* oom while computing effective. Free all computed effective arrays - * since they were not activated - */ - css_for_each_descendant_pre(css, &cgrp->self) { - struct cgroup *desc = container_of(css, struct cgroup, self); - - bpf_prog_array_free(desc->bpf.inactive); - desc->bpf.inactive = NULL; - } - /* and restore back old_prog */ pl->prog = old_prog; return err; @@ -655,6 +675,8 @@ cgroup_dev_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_map_delete_elem_proto; case BPF_FUNC_get_current_uid_gid: return &bpf_get_current_uid_gid_proto; + case BPF_FUNC_get_local_storage: + return &bpf_get_local_storage_proto; case BPF_FUNC_trace_printk: if (capable(CAP_SYS_ADMIN)) return bpf_get_trace_printk_proto(); |