From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.6 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C74B0C433E7 for ; Mon, 31 Aug 2020 20:07:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A415E2078B for ; Mon, 31 Aug 2020 20:07:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729885AbgHaUHo (ORCPT ); Mon, 31 Aug 2020 16:07:44 -0400 Received: from www62.your-server.de ([213.133.104.62]:39058 "EHLO www62.your-server.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726939AbgHaUHm (ORCPT ); Mon, 31 Aug 2020 16:07:42 -0400 Received: from sslproxy01.your-server.de ([78.46.139.224]) by www62.your-server.de with esmtpsa (TLSv1.2:DHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89_1) (envelope-from ) id 1kCq5R-0002uJ-9g; Mon, 31 Aug 2020 22:07:29 +0200 Received: from [178.196.57.75] (helo=pc-9.home) by sslproxy01.your-server.de with esmtpsa (TLSv1.3:TLS_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1kCq5R-000KJE-33; Mon, 31 Aug 2020 22:07:29 +0200 Subject: Re: [PATCH v2 bpf-next] bpf: Fix build without BPF_SYSCALL, but with BPF_JIT. To: Alexei Starovoitov , davem@davemloft.net Cc: paulmck@kernel.org, netdev@vger.kernel.org, bpf@vger.kernel.org, kernel-team@fb.com References: <20200831155155.62754-1-alexei.starovoitov@gmail.com> From: Daniel Borkmann Message-ID: <48c87341-7ad0-6aee-3a11-ba85598b0330@iogearbox.net> Date: Mon, 31 Aug 2020 22:07:28 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.2 MIME-Version: 1.0 In-Reply-To: <20200831155155.62754-1-alexei.starovoitov@gmail.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-Authenticated-Sender: daniel@iogearbox.net X-Virus-Scanned: Clear (ClamAV 0.102.4/25916/Mon Aug 31 15:26:49 2020) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 8/31/20 5:51 PM, Alexei Starovoitov wrote: > From: Alexei Starovoitov > > When CONFIG_BPF_SYSCALL is not set, but CONFIG_BPF_JIT=y > the kernel build fails: > In file included from ../kernel/bpf/trampoline.c:11: > ../kernel/bpf/trampoline.c: In function ‘bpf_trampoline_update’: > ../kernel/bpf/trampoline.c:220:39: error: ‘call_rcu_tasks_trace’ undeclared > ../kernel/bpf/trampoline.c: In function ‘__bpf_prog_enter_sleepable’: > ../kernel/bpf/trampoline.c:411:2: error: implicit declaration of function ‘rcu_read_lock_trace’ > ../kernel/bpf/trampoline.c: In function ‘__bpf_prog_exit_sleepable’: > ../kernel/bpf/trampoline.c:416:2: error: implicit declaration of function ‘rcu_read_unlock_trace’ > > This is due to: > obj-$(CONFIG_BPF_JIT) += trampoline.o > obj-$(CONFIG_BPF_JIT) += dispatcher.o > There is a number of functions that arch/x86/net/bpf_jit_comp.c is > using from these two files, but none of them will be used when > only cBPF is on (which is the case for BPF_SYSCALL=n BPF_JIT=y). > > Add rcu_trace functions to rcupdate_trace.h. The JITed code won't execute them > and BPF trampoline logic won't be used without BPF_SYSCALL. > > Reported-by: kernel test robot > Fixes: 1e6c62a88215 ("bpf: Introduce sleepable BPF programs") > Acked-by: Paul E. McKenney > Signed-off-by: Alexei Starovoitov Applied, thanks!