[PATCH] bpf_trace: Make dependent on PERF_EVENTS

[PATCH] bpf_trace: Make dependent on PERF_EVENTS

[Steven Rostedt]

Arnd Bergmann reported:

  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.

Looking at this further, it's really that UPROBE_EVENT enables PERF_EVENTS.
By just having BPF_EVENTS depend on PERF_EVENTS, then all is fine.

Link: http://lkml.kernel.org/r/4525348.Aq9YoXkChv at wuerfel
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/trace/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 8d6363f42169..e45db6b0d878 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) && PERF_EVENTS
 	bool
 	default y
 	help
-- 
1.8.3.1

[PATCH] bpf_trace: Make dependent on PERF_EVENTS

[Arnd Bergmann]

On Tuesday 10 November 2015 15:28:17 Steven Rostedt wrote:
> Arnd Bergmann reported:
> 
>   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.
> 
> Looking at this further, it's really that UPROBE_EVENT enables PERF_EVENTS.
> By just having BPF_EVENTS depend on PERF_EVENTS, then all is fine.
> 
> Link: http://lkml.kernel.org/r/4525348.Aq9YoXkChv at wuerfel
> Reported-by: Arnd Bergmann <arnd@arndb.de>
> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
> 

Ok, sounds good.

Acked-by: Arnd Bergmann <arnd@arndb.de>

[PATCH] bpf_trace: Make dependent on PERF_EVENTS

[David Miller]

From: Steven Rostedt <rostedt@goodmis.org>
Date: Tue, 10 Nov 2015 15:28:17 -0500

> 
> Arnd Bergmann reported:
> 
>   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.
> 
> Looking at this further, it's really that UPROBE_EVENT enables PERF_EVENTS.
> By just having BPF_EVENTS depend on PERF_EVENTS, then all is fine.
> 
> Link: http://lkml.kernel.org/r/4525348.Aq9YoXkChv at wuerfel
> Reported-by: Arnd Bergmann <arnd@arndb.de>
> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

I'll apply this, thanks Steven et al.

[PATCH] bpf_trace: Make dependent on PERF_EVENTS

[Steven Rostedt]

On Tue, 10 Nov 2015 15:40:35 -0500 (EST)
David Miller <davem@davemloft.net> wrote:


> I'll apply this, thanks Steven et al.

Thanks David.

-- Steve