On Tue, Jun 28, 2016 at 11:58 AM, Oleg Nesterov <[email protected]> wrote: > On 06/27, Oleg Nesterov wrote: >> >> On 06/27, Andy Lutomirski wrote: >> > >> > Want to send a patch? I could do it, but you understand this code >> > much better than I do. >> >> Well, I'll try to do this tomorrow unless you do it. > > I have cloned luto/linux.git to see if kthread_stop() can pin ->stack > somehow, but it seems this is not possible, finish_task_switch() does > free_thread_stack() unconditionally. > > Then how (say) proc_pid_stack() can work? If it hits the task which is > alreay dead we are (probably) fine, valid_stack_ptr() should fail iiuc. >
I changed save_stack_trace_tsk() to use try_get_task_stack(). I think that's sufficient to fix this. --Andy
