From: "Steven Rostedt (Google)" <rostedt@xxxxxxxxxxx>
The callbacks path can possibly be called when the next record is NULL. Do
not call the callbacks in this case, as they are not expecting a NULL
record, nor should they have to.
Move the code that calls the callbacks in tracecmd_iterate_events() and
tracecmd_iterate_events_multi() into a single helper function to alleviate
fixing one and not the other.
Reported-by: Ian Rogers <irogers@xxxxxxxxxx>
Fixes: 3cd1b55f3 ("trace-cmd library: Add tracecmd_follow_event()")
Fixes: 82ed4a937 ("trace-cmd library: Add filtering logic for iterating events")
Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
---
lib/trace-cmd/trace-input.c | 42 ++++++++++++++++++++++++-------------
1 file changed, 28 insertions(+), 14 deletions(-)
diff --git a/lib/trace-cmd/trace-input.c b/lib/trace-cmd/trace-input.c
index d81918249871..6a8ca2e8a6b8 100644
--- a/lib/trace-cmd/trace-input.c
+++ b/lib/trace-cmd/trace-input.c
@@ -2648,6 +2648,29 @@ static int call_followers(struct tracecmd_input *handle,
return ret;
}
+static int call_callbacks(struct tracecmd_input *handle, struct tep_record *record,
+ int next_cpu,
+ int (*callback)(struct tracecmd_input *handle,
+ struct tep_record *,
+ int, void *),
+ void *callback_data)
+{
+ int ret = 0;
+
+ if (!record)
+ return 0;
+
+ if (!handle->filter ||
+ tracecmd_filter_match(handle->filter, record) == TRACECMD_FILTER_MATCH) {
+ if (handle->nr_followers)
+ ret = call_followers(handle, record, next_cpu);
+ if (!ret && callback)
+ ret = callback(handle, record, next_cpu, callback_data);
+ }
+
+ return ret;
+}
+
/**
* tracecmd_iterate_events - iterate events over a given handle
* @handle: The handle to iterate over
@@ -2709,13 +2732,9 @@ int tracecmd_iterate_events(struct tracecmd_input *handle,
record = tracecmd_read_data(handle, next_cpu);
records[next_cpu] = tracecmd_peek_data(handle, next_cpu);
- if (!handle->filter ||
- tracecmd_filter_match(handle->filter, record) == TRACECMD_FILTER_MATCH) {
- if (handle->nr_followers)
- ret = call_followers(handle, record, next_cpu);
- if (!ret && callback)
- ret = callback(handle, record, next_cpu, callback_data);
- }
+ ret = call_callbacks(handle, record, next_cpu,
+ callback, callback_data);
+
tracecmd_free_record(record);
}
} while (next_cpu >= 0 && ret >= 0);
@@ -2803,14 +2822,9 @@ int tracecmd_iterate_events_multi(struct tracecmd_input **handles,
record = tracecmd_read_data(handle, cpu);
records[next_cpu].record = tracecmd_peek_data(handle, cpu);
- if (!handle->filter ||
- tracecmd_filter_match(handle->filter, record) == TRACECMD_FILTER_MATCH) {
- if (handle->nr_followers)
- ret = call_followers(handle, record, next_cpu);
+ ret = call_callbacks(handle, record, next_cpu,
+ callback, callback_data);
- if (!ret && callback)
- ret = callback(handle, record, next_cpu, callback_data);
- }
tracecmd_free_record(record);
}
--
2.35.1
|