The kbuffer_next_event() will return the next event on the sub buffer.
If we pass in the last_record to tracecmd_read_page_record(), it
initializes the sub buffer, and by calling kbuffer_next_event()
(instead of kbuffer_read_event()), the second event on the sub buffer
is returned. This causes the match of the last_record not to match if
the last_record happens to be the first event on the sub buffer.
Signed-off-by: Tzvetomir Stoyanov <tstoyanov@xxxxxxxxxx>
---
lib/trace-cmd/trace-input.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/lib/trace-cmd/trace-input.c b/lib/trace-cmd/trace-input.c
index 6624932..ea11d62 100644
--- a/lib/trace-cmd/trace-input.c
+++ b/lib/trace-cmd/trace-input.c
@@ -1695,18 +1695,22 @@ tracecmd_read_page_record(struct tep_handle *pevent, void *page, int size,
goto out_free;
}
- do {
+ ptr = kbuffer_read_event(kbuf, &ts);
+ while (ptr < last_record->data) {
ptr = kbuffer_next_event(kbuf, NULL);
if (!ptr)
break;
- } while (ptr < last_record->data);
+ if (ptr == last_record->data)
+ break;
+ }
if (ptr != last_record->data) {
warning("tracecmd_read_page_record: could not find last_record");
goto out_free;
}
- }
+ ptr = kbuffer_next_event(kbuf, &ts);
+ } else
+ ptr = kbuffer_read_event(kbuf, &ts);
- ptr = kbuffer_read_event(kbuf, &ts);
if (!ptr)
goto out_free;
--
2.20.1
|