[PATCH] ring-buffer: mark racy accesses on work->wait_index

[linke li]

Mark data races to work->wait_index as benign using READ_ONCE and WRITE_ONCE. 
These accesses are expected to be racy.

Signed-off-by: linke li <lilink...@qq.com>
---
 kernel/trace/ring_buffer.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 0699027b4f4c..a47e9e9750cc 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -798,7 +798,7 @@ void ring_buffer_wake_waiters(struct trace_buffer *buffer, 
int cpu)
                rbwork = &cpu_buffer->irq_work;
        }
 
-       rbwork->wait_index++;
+       WRITE_ONCE(rbwork->wait_index, READ_ONCE(rbwork->wait_index) + 1);
        /* make sure the waiters see the new index */
        smp_wmb();
 
@@ -906,7 +906,7 @@ int ring_buffer_wait(struct trace_buffer *buffer, int cpu, 
int full)
 
                /* Make sure to see the new wait index */
                smp_rmb();
-               if (wait_index != work->wait_index)
+               if (wait_index != READ_ONCE(work->wait_index))
                        break;
        }
 
-- 
2.39.3 (Apple Git-145)