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| author | Steven Rostedt <srostedt@redhat.com> | 2010-06-10 14:53:16 -0400 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2010-06-10 20:56:54 -0400 |
| commit | a8fb2608053547bc3152ea61a5ec7cdfce5d942c (patch) | |
| tree | 08f5fd61dd3fce05a2472f457c48ec249966b372 /kernel | |
| parent | d11007703c31db534674ebeeb9eb047bbbe758bd (diff) | |
| download | blackbird-op-linux-a8fb2608053547bc3152ea61a5ec7cdfce5d942c.tar.gz blackbird-op-linux-a8fb2608053547bc3152ea61a5ec7cdfce5d942c.zip | |
perf/tracing: Fix regression of perf losing kprobe events
With the addition of the code to shrink the kernel tracepoint
infrastructure, we lost kprobes being traced by perf. The reason
is that I tested if the "tp_event->class->perf_probe" existed before
enabling it. This prevents "ftrace only" events (like the function
trace events) from being enabled by perf.
Unfortunately, kprobe events do not use perf_probe. This causes
kprobes to be missed by perf. To fix this, we add the test to
see if "tp_event->class->reg" exists as well as perf_probe.
Normal trace events have only "perf_probe" but no "reg" function,
and kprobes and syscalls have the "reg" but no "perf_probe".
The ftrace unique events do not have either, so this is a valid
test. If a kprobe or syscall is not to be probed by perf, the
"reg" function is called anyway, and will return a failure and
prevent perf from probing it.
Reported-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Tested-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/trace_event_perf.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c index e6f65887842c..8a2b73f7c068 100644 --- a/kernel/trace/trace_event_perf.c +++ b/kernel/trace/trace_event_perf.c @@ -96,7 +96,9 @@ int perf_trace_init(struct perf_event *p_event) mutex_lock(&event_mutex); list_for_each_entry(tp_event, &ftrace_events, list) { if (tp_event->event.type == event_id && - tp_event->class && tp_event->class->perf_probe && + tp_event->class && + (tp_event->class->perf_probe || + tp_event->class->reg) && try_module_get(tp_event->mod)) { ret = perf_trace_event_init(tp_event, p_event); break; |
