taskdump -t 6 deadlocks VFS and taskdump

[Jakub Jermář]

When one does:

/ # taskdump -t 6

taskdump begins a udebug session with task 6 (usually vfs), reads its name over udebug and attempts to print a message:

        printf("Dumping task '%s' (task ID %" PRIu64 ").\n", app_name, task_id);

Now printf() needs to make a call to vfs, but since vfs is being debugged, there is no-one to process the request and answer it. So taskdump cannot proceed towards ending the udebug session with vfs and these two tasks hang.

Something similar happens when tracing vfs using trace. It is possible to kill the taskdump task, but for some reason vfs remains hung.