On Wed, Sep 21, 2016 at 8:43 AM, Roman Pen <roman.peny...@profitbricks.com> wrote: > kthread uses stack and keeps completion structure on it to be woken up > on vfork_done completion. > > In commit 2deb4be28 Andy Lutomirski rewinds the stack unconditionally > and further completion of task->vfork_done for any kthread leads to stack > corruption (or infinite spin on attempt to spin lock on garbage memory).
This is sort of okay, but it will blow up pretty badly if a kthread overflows its stack. Would it make more sense to change rewind_stack_do_exit() to leave a big enough gap at the top of the stack to avoid clobbering the completion? --Andy
