/* Called from syscall */ static struct bpf_map *stack_map_alloc(union bpf_attr *attr) { u32 value_size = attr->value_size; struct bpf_stack_map *smap; u64 cost, n_buckets; int err; if (!capable(CAP_SYS_ADMIN)) return ERR_PTR(-EPERM); if (attr->map_flags & ~STACK_CREATE_FLAG_MASK) return ERR_PTR(-EINVAL); /* check sanity of attributes */ if (attr->max_entries == 0 || attr->key_size != 4 || value_size < 8 || value_size % 8 || value_size / 8 > sysctl_perf_event_max_stack) return ERR_PTR(-EINVAL); /* hash table size must be power of 2 */ n_buckets = roundup_pow_of_two(attr->max_entries); cost = n_buckets * sizeof(struct stack_map_bucket *) + sizeof(*smap); if (cost >= U32_MAX - PAGE_SIZE) return ERR_PTR(-E2BIG); smap = bpf_map_area_alloc(cost, bpf_map_attr_numa_node(attr)); if (!smap) return ERR_PTR(-ENOMEM); err = -E2BIG; cost += n_buckets * (value_size + sizeof(struct stack_map_bucket)); if (cost >= U32_MAX - PAGE_SIZE) goto free_smap; bpf_map_init_from_attr(&smap->map, attr); smap->map.value_size = value_size; smap->n_buckets = n_buckets; smap->map.pages = round_up(cost, PAGE_SIZE) >> PAGE_SHIFT; err = bpf_map_precharge_memlock(smap->map.pages); if (err) goto free_smap; err = get_callchain_buffers(sysctl_perf_event_max_stack); if (err) goto free_smap; err = prealloc_elems_and_freelist(smap); if (err) goto put_buffers; return &smap->map; put_buffers: put_callchain_buffers(); free_smap: bpf_map_area_free(smap); return ERR_PTR(err); }
struct bpf_map *bpf_map_offload_map_alloc(union bpf_attr *attr) { struct net *net = current->nsproxy->net_ns; struct bpf_offloaded_map *offmap; int err; if (!capable(CAP_SYS_ADMIN)) return ERR_PTR(-EPERM); if (attr->map_type != BPF_MAP_TYPE_ARRAY && attr->map_type != BPF_MAP_TYPE_HASH) return ERR_PTR(-EINVAL); offmap = kzalloc(sizeof(*offmap), GFP_USER); if (!offmap) return ERR_PTR(-ENOMEM); bpf_map_init_from_attr(&offmap->map, attr); rtnl_lock(); down_write(&bpf_devs_lock); offmap->netdev = __dev_get_by_index(net, attr->map_ifindex); err = bpf_dev_offload_check(offmap->netdev); if (err) goto err_unlock; err = bpf_map_offload_ndo(offmap, BPF_OFFLOAD_MAP_ALLOC); if (err) goto err_unlock; list_add_tail(&offmap->offloads, &bpf_map_offload_devs); up_write(&bpf_devs_lock); rtnl_unlock(); return &offmap->map; err_unlock: up_write(&bpf_devs_lock); rtnl_unlock(); kfree(offmap); return ERR_PTR(err); }