1 files changed, 5 insertions, 1 deletions

diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index c87766c1c204..e06cde093f76 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -280,6 +280,8 @@ EXPORT_SYMBOL_GPL(ring_buffer_event_data);
 /* Missed count stored at end */
 #define RB_MISSED_STORED        (1 << 30)
 
+#define RB_MISSED_FLAGS         (RB_MISSED_EVENTS|RB_MISSED_STORED)
+
 struct buffer_data_page {
         u64              time_stamp;    /* page time stamp */
         local_t          commit;        /* write committed index */
@@ -331,7 +333,9 @@ static void rb_init_page(struct buffer_data_page *bpage)
  */
 size_t ring_buffer_page_len(void *page)
 {
-        return local_read(&((struct buffer_data_page *)page)->commit)
+        struct buffer_data_page *bpage = page;
+
+        return (local_read(&bpage->commit) & ~RB_MISSED_FLAGS)
                 + BUF_PAGE_HDR_SIZE;
 }