Messages in this thread | | | Date | Tue, 10 Nov 2015 14:31:38 +0100 | From | Daniel Borkmann <> | Subject | Re: [PATCH, REPORT] bpf_trace: build error without PERF_EVENTS |
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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.
> Simply hiding the broken code inside #ifdef CONFIG_PERF_EVENTS > as this patch does seems to reliably fix the error as well, > I have built thousands of randconfig kernels since I started > seeing this and added the workaround. > > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > Fixes: 62544ce8e01c ("bpf: fix bpf_perf_event_read() helper") > Fixes: a43eec304259 ("bpf: introduce bpf_perf_event_output() helper")
Thanks, Daniel
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