Am 07.04.22 um 05:17 schrieb Zheyu Ma:
I found a bug when removing the adt7470 module. The following log can reveal it: [ 18.459479] ------------[ cut here ]------------ [ 18.459852] do not call blocking ops when !TASK_RUNNING; state=1 set at [<ffffffffa006052b>] adt7470_update_thread+0x7b/0x130 [adt7470] [ 18.460857] WARNING: CPU: 7 PID: 365 at kernel/sched/core.c:9660 __might_sleep+0x96/0xb0 [ 18.461523] Modules linked in: adt7470(-) [ 18.464568] RIP: 0010:__might_sleep+0x96/0xb0 [ 18.472577] Call Trace: [ 18.472778] <TASK> [ 18.472957] exit_signals+0x2f/0x3b0 [ 18.473251] do_exit+0xcd/0x18c0 [ 18.473534] ? __mutex_unlock_slowpath+0x1b8/0x740 [ 18.473927] kthread_exit+0x42/0x60 [ 18.474212] ? adt7470_detect+0x140/0x140 [adt7470] [ 18.474622] kthread+0x272/0x2e0 [ 18.474885] ? adt7470_detect+0x140/0x140 [adt7470] [ 18.475277] ? kthread_blkcg+0xa0/0xa0 [ 18.475601] ret_from_fork+0x22/0x30 [ 18.475901] </TASK> Regards, Zheyu Ma
Please correct me if i am wrong, but i think the issue lies in adt7470_update_thread() leaving the kthread in TASK_INTERRUPTIBLE state when the second check for kthread_should_stop() returns true and causes the kthread to exit. Since kthread_exit() might sleep in exit_signals(), we get this warning. Maybe moving set_current_state(TASK_INTERRUPTIBLE) below the second check for kthread_should_stop() would fix the issue? Armin Wolf
