1 files changed, 12 insertions, 0 deletions

diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index bb6922a931b1..d03f4f44a823 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -838,6 +838,7 @@ rb_set_commit_to_write(struct ring_buffer_per_cpu *cpu_buffer)
          * back to us). This allows us to do a simple loop to
          * assign the commit to the tail.
          */
+ again:
         while (cpu_buffer->commit_page != cpu_buffer->tail_page) {
                 cpu_buffer->commit_page->page->commit =
                         cpu_buffer->commit_page->write;
@@ -853,6 +854,17 @@ rb_set_commit_to_write(struct ring_buffer_per_cpu *cpu_buffer)
                         cpu_buffer->commit_page->write;
                 barrier();
         }
+
+        /* again, keep gcc from optimizing */
+        barrier();
+
+        /*
+         * If an interrupt came in just after the first while loop
+         * and pushed the tail page forward, we will be left with
+         * a dangling commit that will never go forward.
+         */
+        if (unlikely(cpu_buffer->commit_page != cpu_buffer->tail_page))
+                goto again;
 }
 
 static void rb_reset_reader_page(struct ring_buffer_per_cpu *cpu_buffer)