PT_F_ALLBITS
KASSERT((((uintptr_t)p) & PT_F_ALLBITS) == 0);
KASSERT((((uintptr_t)l) & PT_F_ALLBITS) == 0);
#define PT_GET_LWP(s) ((struct lwp *)((s) & ~PT_F_ALLBITS))
#define PT_GET_PROC(s) ((struct proc *)((s) & ~PT_F_ALLBITS))
#define MIN_PROC_ALIGNMENT (PT_F_ALLBITS + 1)