to extract the PC from that to send to addupc_task() so that it can be
called from MI code.
- Remove all traces of have_giant with extreme prejudice and use
mtx_owned(&Giant) instead where appropriate.
- Proc locking.
- P_FOO -> PS_FOO.
- Don't grab Giant just to look in curproc's p_addr during a trap since we
may choose to immediately exit. Instead, delay grabbing Giant a bit
until we actually need it.
- Don't reset 'p' to 'curproc' in syscall() to handle the case of a child
returning from fork1() since children don't return via syscall().
- Remove an XXX comment in ast() that questions the correctness of the
userland check. The code is correct.
eabcf31b82