process_sstep
process_sstep(p, 0);
# define FIX_SSTEP(p) process_sstep(p, 0)
int process_sstep(struct proc *, int);
process_sstep(p, 0);
error = process_sstep(t, req == PT_STEP);
error = process_sstep(t, 0);
int process_sstep(struct proc *_t, int _sstep);