In function ring_buffer_iter_empty(), cpu_buffer->commit_page and curr_commit_page->page->time_stamp is read using READ_ONCE() in line 4354, 4355
4354 curr_commit_page = READ_ONCE(cpu_buffer->commit_page); 4355 curr_commit_ts = READ_ONCE(curr_commit_page->page->time_stamp); while they are read directly in line 4340, 4341 4340 commit_page = cpu_buffer->commit_page; 4341 commit_ts = commit_page->page->time_stamp; There is patch similar to this. commit c1c0ce31b242 ("r8169: fix the KCSAN reported data-race in rtl_tx() while reading tp->cur_tx") This patch find two read of same variable while one is protected, another is not. And READ_ONCE() is added to protect. 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..eb3fa629b837 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -4337,8 +4337,8 @@ int ring_buffer_iter_empty(struct ring_buffer_iter *iter) cpu_buffer = iter->cpu_buffer; reader = cpu_buffer->reader_page; head_page = cpu_buffer->head_page; - commit_page = cpu_buffer->commit_page; - commit_ts = commit_page->page->time_stamp; + commit_page = READ_ONCE(cpu_buffer->commit_page); + commit_ts = READ_ONCE(commit_page->page->time_stamp); /* * When the writer goes across pages, it issues a cmpxchg which -- 2.39.3 (Apple Git-145)