ia32_osigframe
struct ia32_osigframe sf, *fp;
fp = (struct ia32_osigframe *)((uintptr_t)td->td_sigstk.ss_sp +
fp = (struct ia32_osigframe *)regs->tf_rsp - 1;
ASSYM(IA32_SIGF_SC, offsetof(struct ia32_osigframe, sf_siginfo.si_sc));