LKFT started testing KCSAN enabled kernel from the linux next tree. Here we have found BUG: KCSAN: data-race in __rpc_do_wake_up_task_on_wq / xprt_request_transmit This report is from an x86_64 machine clang-11 linux next 20201201. Since we are running for the first time we do not call this regression. [ 17.316725] BUG: KCSAN: data-race in __rpc_do_wake_up_task_on_wq / xprt_request_transmit [ 17.324821] [ 17.326322] write to 0xffff90a801de6a9c of 2 bytes by task 142 on cpu 1: [ 17.333022] __rpc_do_wake_up_task_on_wq+0x295/0x350 [ 17.337987] rpc_wake_up_queued_task+0x99/0xc0 [ 17.342432] xprt_complete_rqst+0xef/0x100 [ 17.346533] xs_read_stream+0x9c6/0xc40 [ 17.350370] xs_stream_data_receive+0x60/0x130 [ 17.354819] xs_stream_data_receive_workfn+0x5c/0x90 [ 17.359784] process_one_work+0x4a6/0x830 [ 17.363795] worker_thread+0x5f7/0xaa0 [ 17.367548] kthread+0x20b/0x220 [ 17.370780] ret_from_fork+0x22/0x30 [ 17.374359] [ 17.375858] read to 0xffff90a801de6a9c of 2 bytes by task 249 on cpu 3: [ 17.382473] xprt_request_transmit+0x389/0x7a0 [ 17.386919] xprt_transmit+0xfe/0x250 [ 17.390583] call_transmit+0x10d/0x120 [ 17.394337] __rpc_execute+0x12d/0x700 [ 17.398089] rpc_async_schedule+0x59/0x90 [ 17.402100] process_one_work+0x4a6/0x830 [ 17.406114] worker_thread+0x5f7/0xaa0 [ 17.409868] kthread+0x20b/0x220 [ 17.413099] ret_from_fork+0x22/0x30 [ 17.416675] [ 17.418167] Reported by Kernel Concurrency Sanitizer on: [ 17.423475] CPU: 3 PID: 249 Comm: kworker/u8:1 Not tainted 5.10.0-rc6-next-20201201 #2 [ 17.431385] Hardware name: Supermicro SYS-5019S-ML/X11SSH-F, BIOS 2.2 05/23/2018 [ 17.438778] Workqueue: rpciod rpc_async_schedule metadata: git_repo: https://gitlab.com/aroxell/lkft-linux-next target_arch: x86 toolchain: clang-11 git_describe: next-20201201 download_url: https://builds.tuxbuild.com/1l8eiWgGMi6W4aDobjAAlOleFVl/ Full test log link, https://lkft.validation.linaro.org/scheduler/job/2002643#L1005 -- Linaro LKFT https://lkft.linaro.org