Message ID | 4525348.Aq9YoXkChv@wuerfel (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
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
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 4228fd3682c3..82e0bc9d002a 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -186,6 +186,7 @@ const struct bpf_func_proto *bpf_get_trace_printk_proto(void) return &bpf_trace_printk_proto; } +#if IS_ENABLED(CONFIG_PERF_EVENTS) static u64 bpf_perf_event_read(u64 r1, u64 index, u64 r3, u64 r4, u64 r5) { struct bpf_map *map = (struct bpf_map *) (unsigned long) r1; @@ -263,6 +264,7 @@ static const struct bpf_func_proto bpf_perf_event_output_proto = { .arg4_type = ARG_PTR_TO_STACK, .arg5_type = ARG_CONST_STACK_SIZE, }; +#endif static const struct bpf_func_proto *kprobe_prog_func_proto(enum bpf_func_id func_id) { @@ -289,10 +291,12 @@ static const struct bpf_func_proto *kprobe_prog_func_proto(enum bpf_func_id func return bpf_get_trace_printk_proto(); case BPF_FUNC_get_smp_processor_id: return &bpf_get_smp_processor_id_proto; +#if IS_ENABLED(CONFIG_PERF_EVENTS) case BPF_FUNC_perf_event_read: return &bpf_perf_event_read_proto; case BPF_FUNC_perf_event_output: return &bpf_perf_event_output_proto; +#endif default: return NULL; }
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. 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") --- I suspect my patch is not the right answer, but could someone please fix this?