1e656b349d
as living processes before they are cleaned up (fixes wait()/waitpid() hanging forever on previously-ZOMBIE processes) . stop processes from running using sys_nice() with PRIO_STOP when a handled signal is delivered, before computing stack locations for sys_sigsend(). (fixes race condition when runnable processes get signals, and e.g. get scheduled before FS sends a reply to unpause(), which can make the signal stack location wrong.)