SS_ONSTACK
if (lp->lwp_sigstk.ss_flags & SS_ONSTACK)
lp->lwp_sigstk.ss_flags |= SS_ONSTACK;
lp->lwp_sigstk.ss_flags &= ~SS_ONSTACK;
oonstack = (lp->lwp_sigstk.ss_flags & SS_ONSTACK) ? 1 : 0;
lp->lwp_sigstk.ss_flags |= SS_ONSTACK;
oonstack = (lp->lwp_sigstk.ss_flags & SS_ONSTACK) ? 1 : 0;
lp->lwp_sigstk.ss_flags |= SS_ONSTACK;
lp->lwp_sigstk.ss_flags |= SS_ONSTACK;
lp->lwp_sigstk.ss_flags &= ~SS_ONSTACK;