Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1266658

Re: [PATCH, REPORT] bpf_trace: build error without PERF_EVENTS

From Alexei Starovoitov <alexei.starovoitov@gmail.com>
Newsgroups linux.kernel
Subject Re: [PATCH, REPORT] bpf_trace: build error without PERF_EVENTS
Date 2015-11-10 18:20 +0100
Message-ID <qtkKn-7Wr-23@gated-at.bofh.it> (permalink)
References <qtgQq-5uz-9@gated-at.bofh.it> <qthjr-5Fv-9@gated-at.bofh.it> <qti5Q-6bC-5@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw


On Tue, Nov 10, 2015 at 09:25:01AM -0500, Steven Rostedt wrote:
> On Tue, 10 Nov 2015 14:31:38 +0100
> Daniel Borkmann <daniel@iogearbox.net> 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.

--
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/

Back to linux.kernel | Previous | NextPrevious in thread | Next in thread | Find similar | Unroll thread


Thread

[PATCH, REPORT] bpf_trace: build error without PERF_EVENTS Arnd Bergmann <arnd@arndb.de> - 2015-11-10 14:10 +0100
  Re: [PATCH, REPORT] bpf_trace: build error without PERF_EVENTS Daniel Borkmann <daniel@iogearbox.net> - 2015-11-10 14:40 +0100
    Re: [PATCH, REPORT] bpf_trace: build error without PERF_EVENTS Steven Rostedt <rostedt@goodmis.org> - 2015-11-10 15:30 +0100
      Re: [PATCH, REPORT] bpf_trace: build error without PERF_EVENTS Alexei Starovoitov <alexei.starovoitov@gmail.com> - 2015-11-10 18:20 +0100
        Re: [PATCH, REPORT] bpf_trace: build error without PERF_EVENTS Daniel Borkmann <daniel@iogearbox.net> - 2015-11-10 18:30 +0100

csiph-web