[PATCH] ftrace: fix perf-tracepoint OOPS

Peter Zijlstra
2009-08-05T18:41:13Z

Not all tracepoints are created equal, in specific the ftrace
tracepoints are created with TRACE_EVENT_FORMAT() which does not
generate the needed bits to tie them into perf counters.

For those events, don't create the 'id' file and fail ->profile_enable
when their ID is specified through other means.

Reported-by: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
---
kernel/trace/trace_event_profile.c | 2 +-
kernel/trace/trace_events.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/trace/trace_event_profile.c b/kernel/trace/trace_event_profile.c
index 5b5895a..11ba5bb 100644
--- a/kernel/trace/trace_event_profile.c
+++ b/kernel/trace/trace_event_profile.c
@@ -14,7 +14,7 @@ int ftrace_profile_enable(int event_id)

mutex_lock(&event_mutex);
list_for_each_entry(event, &ftrace_events, list) {
- if (event->id == event_id) {
+ if (event->id == event_id && event->profile_enable) {
ret = event->profile_enable(event);
break;
}
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 90cdec5..e2b301d 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -971,7 +971,7 @@ event_create_dir(struct ftrace_event_call *call, struct dentry *d_events,
entry = trace_create_file("enable", 0644, call->dir, call,
enable);

- if (call->id)
+ if (call->id && call->profile_enable)
entry = trace_create_file("id", 0444, call->dir, call,
id);