OZZ: Identifying Kernel Out-of-Order Concurrency Bugs with In-Vivo Memory Access Reordering

Kernel concurrency bugs are notoriously difficult to identify, while their consequences severely threaten the reliability and security of the entire system. Especially in the kernel, developers should consider not only locks but also memory barriers to prevent out-of-order execution from breaking the correctness of concurrent execution. Incorrect use of memory barriers may cause non-intuitive concurrency bugs that manifest due to out-of-order execution, which we refer to as OoO bugs.