Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754695AbbG3BoP (ORCPT ); Wed, 29 Jul 2015 21:44:15 -0400 Received: from mail-pa0-f51.google.com ([209.85.220.51]:33156 "EHLO mail-pa0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754508AbbG3BoO (ORCPT ); Wed, 29 Jul 2015 21:44:14 -0400 Subject: Re: [PATCH v4 1/4] bpf: Make the bpf_prog_array_map more generic To: Daniel Borkmann , Kaixu Xia , davem@davemloft.net, acme@kernel.org, mingo@redhat.com, a.p.zijlstra@chello.nl, masami.hiramatsu.pt@hitachi.com, jolsa@kernel.org References: <1438082255-60683-1-git-send-email-xiakaixu@huawei.com> <1438082255-60683-2-git-send-email-xiakaixu@huawei.com> <55B95F06.4040800@iogearbox.net> Cc: wangnan0@huawei.com, linux-kernel@vger.kernel.org, pi3orama@163.com, hekuang@huawei.com From: Alexei Starovoitov Message-ID: <55B9816B.5020801@plumgrid.com> Date: Wed, 29 Jul 2015 18:44:11 -0700 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.10; rv:38.0) Gecko/20100101 Thunderbird/38.1.0 MIME-Version: 1.0 In-Reply-To: <55B95F06.4040800@iogearbox.net> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1130 Lines: 26 On 7/29/15 4:17 PM, Daniel Borkmann wrote: >> - if (map->map_type == BPF_MAP_TYPE_PROG_ARRAY) >> + if (map->map_type >= BPF_MAP_TYPE_PROG_ARRAY) >> /* prog_array stores refcnt-ed bpf_prog pointers >> * release them all when user space closes prog_array_fd >> */ >> - bpf_prog_array_map_clear(map); >> + bpf_fd_array_map_clear(map); > > When we are going to add a new map type to the eBPF framework that is not > an fd_array_map thing, this assumption of map->map_type >= > BPF_MAP_TYPE_PROG_ARRAY > might not hold then ... Also I think here changing == to >= is probably unnecessary. prog_array needs to do it because of circular dependency whereas perf_event_array cannot have it. Even when we attach bpf prog to perf_event and then add it to perf_event_array used by the same prog, right? Please test such scenario just in case. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/