ia32_freebsd4_sigframe
struct ia32_freebsd4_sigframe sf, *sfp;
sfp = (struct ia32_freebsd4_sigframe *)((uintptr_t)td->td_sigstk.ss_sp +
sfp = (struct ia32_freebsd4_sigframe *)regs->tf_rsp - 1;
ASSYM(IA32_SIGF_UC4, offsetof(struct ia32_freebsd4_sigframe, sf_uc));
CTASSERT(sizeof(struct ia32_freebsd4_sigframe) == 408);