Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751417AbbKJRXY (ORCPT ); Tue, 10 Nov 2015 12:23:24 -0500 Received: from www62.your-server.de ([213.133.104.62]:38684 "EHLO www62.your-server.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750765AbbKJRXW (ORCPT ); Tue, 10 Nov 2015 12:23:22 -0500 Message-ID: <56422802.5050901@iogearbox.net> Date: Tue, 10 Nov 2015 18:23:14 +0100 From: Daniel Borkmann User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 MIME-Version: 1.0 To: Alexei Starovoitov , Steven Rostedt CC: Arnd Bergmann , Ingo Molnar , linux-kernel@vger.kernel.org, Alexei Starovoitov , "David S. Miller" , Kaixu Xia , Hannes Frederic Sowa , Wang Nan , netdev@vger.kernel.org, Arnaldo Carvalho de Melo , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH, REPORT] bpf_trace: build error without PERF_EVENTS References: <4525348.Aq9YoXkChv@wuerfel> <5641F1BA.6040701@iogearbox.net> <20151110092501.0bc676c9@gandalf.local.home> <20151110171421.GA21650@ast-mbp.thefacebook.com> In-Reply-To: <20151110171421.GA21650@ast-mbp.thefacebook.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-Authenticated-Sender: daniel@iogearbox.net Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1973 Lines: 50 On 11/10/2015 06:14 PM, Alexei Starovoitov wrote: > On Tue, Nov 10, 2015 at 09:25:01AM -0500, Steven Rostedt wrote: >> On Tue, 10 Nov 2015 14:31:38 +0100 >> Daniel Borkmann wrote: >> >>> On 11/10/2015 01:55 PM, Arnd Bergmann wrote: >>>> In my ARM randconfig tests, I'm getting a build error for >>>> newly added code in bpf_perf_event_read and bpf_perf_event_output >>>> whenever CONFIG_PERF_EVENTS is disabled: >>>> >>>> kernel/trace/bpf_trace.c: In function 'bpf_perf_event_read': >>>> kernel/trace/bpf_trace.c:203:11: error: 'struct perf_event' has no member named 'oncpu' >>>> if (event->oncpu != smp_processor_id() || >>>> ^ >>>> kernel/trace/bpf_trace.c:204:11: error: 'struct perf_event' has no member named 'pmu' >>>> event->pmu->count) >>>> >>>> This can happen when UPROBE_EVENT is enabled but KPROBE_EVENT >>>> is disabled. I'm not sure if that is a configuration we care >>>> about, otherwise we could prevent this case from occuring by >>>> adding Kconfig dependencies. >>> >>> I think that seems better than spreading #if IS_ENABLEDs into the code. >>> Probably enough to add a 'depends on PERF_EVENTS' to config BPF_EVENTS, >>> so it's also explicitly documented. >>> >> >> So just do the following then? >> >> -- Steve >> >> diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig >> index 8d6363f42169..f5aecff2d243 100644 >> --- a/kernel/trace/Kconfig >> +++ b/kernel/trace/Kconfig >> @@ -434,7 +434,7 @@ config UPROBE_EVENT >> >> config BPF_EVENTS >> depends on BPF_SYSCALL >> - depends on KPROBE_EVENT || UPROBE_EVENT >> + depends on KPROBE_EVENT && UPROBE_EVENT > > yeah that's definitely cleaner and avoids ifdef creep in the future. Agreed, that's better. -- 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/