diff options
| -rw-r--r-- | kernel/trace/ring_buffer.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 9ed509a015d8..bd1c35a4fbcc 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -3853,6 +3853,13 @@ int ring_buffer_read_page(struct ring_buffer *buffer, /* Need to copy one event at a time */ do { + /* We need the size of one event, because + * rb_advance_reader only advances by one event, + * whereas rb_event_ts_length may include the size of + * one or two events. + * We have already ensured there's enough space if this + * is a time extend. */ + size = rb_event_length(event); memcpy(bpage->data + pos, rpage->data + rpos, size); len -= size; @@ -3867,7 +3874,7 @@ int ring_buffer_read_page(struct ring_buffer *buffer, event = rb_reader_event(cpu_buffer); /* Always keep the time extend and data together */ size = rb_event_ts_length(event); - } while (len > size); + } while (len >= size); /* update bpage */ local_set(&bpage->commit, pos); |