> > Then the patch will be like: > > > > @@ -883,10 +883,9 @@ static int kill_accessing_process(struct task_struct *p, unsigned long pfn, > > (void *)&priv); > > if (ret == 1 && priv.tk.addr) > > kill_proc(&priv.tk, pfn, flags); > > - else > > - ret = 0; > > mmap_read_unlock(p->mm); > > - return ret > 0 ? -EHWPOISON : -EFAULT; > > + > > + return ret > 0 ? -EHWPOISON : 0; > > > > Here, returning 0 indicates that memory_failure() successfully handled the > > error by dropping the clean page. > > I'm not sure whether there's another scene that can make walk_page_range() returns 0. But if the > only reason for walk_page_range() returning 0 is the poison page is a clean page and it's dropped, > then this modification should be appropriate. With this change, the callers never send SIGBUS now. > They might need to be changed too. Note there shouldn't be a SIGBUS when the action was "dropping a clean page". Full recovery is possible in this case (user process takes #PF, Linux allocates a new page and fills by reading from storage). -Tony
