> >access_ok() always returns 1. > > Thanks for pointing it out. And, I didn't notice that gup is just built for > SPARC64. I though it is built by both 64 bit and 32 bit. > > A follow-up question, is there any reason to just have sparc specific fast > gup for 64 bit not for 32 bit? I do not know - sorry. > >>@@ -203,6 +206,8 @@ int get_user_pages_fast(unsigned long start, int nr_pages, int write, > >> addr = start; > >> len = (unsigned long) nr_pages << PAGE_SHIFT; > >> end = start + len; > >>+ if (end < start) > >>+ goto slow_irqon; > > > >end can only be smaller than start if there is some overflow. > >See how end is calculated just the line above. > > > >This looks like a highly suspicious change. > > I'm supposed this is used to protect the overflow. I copied the code from > other arch. Actually, every arch has this except sparc. The the other archs are likely confused as well - there is most likely some history behind that can be found if digging a little. The code is not present in the generic version. Sam -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
