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. But what if we race with the last schedule() ? "addr = *stack" can read the already vfree'ed memory, no? Looks like print_context_stack/etc need probe_kernel_address or I missed something. Oleg.
