sigaction_args
{ .sy_narg = AS(sigaction_args), .sy_call = (sy_call_t *)sys_sigaction, .sy_auevent = AUE_SIGACTION, .sy_flags = SYF_CAPENABLED, .sy_thrcnt = SY_THR_STATIC }, /* 416 = sigaction */
sys_sigaction(struct thread *td, struct sigaction_args *uap)
struct sigaction_args *p = params;
int sys_sigaction(struct thread *, struct sigaction_args *);