cfork
return (cfork(1, 1, NULL, 0));
return (cfork(0, 1, NULL, flags)); /* forkx(flags) */
return (cfork(0, 0, NULL, flags)); /* forkallx(flags) */
return (cfork(1, 1, NULL, flags)); /* vforkx(flags) */
int64_t cfork(int, int, kspawn_param_t *, int);
ret = cfork(0, 0, ksp, spawn_forkflags(sp));
extern int64_t cfork(int, int, kspawn_param_t *, int);