On Fri, Mar 16, 2012 at 02:15:29PM +1100, matthew green wrote:
>
> > Module Name: src
> > Committed By: bouyer
> > Date: Thu Mar 15 18:38:37 UTC 2012
> >
> > Modified Files:
> > src/sys/dev/usb: ehci.c
> >
> > Log Message:
> > Do not read array before detecting array overflow, found by gcc -O3
>
> hmmmm.
>
> seems like this should move the DIAG code to just the printf(). this
> totally changes the behaviour of the failure mode as-is.
>
> we can detect an overflow here but let non-DIAG code fail.
You mean, something like that:
Index: ehci.c
===================================================================
RCS file: /cvsroot/src/sys/dev/usb/ehci.c,v
retrieving revision 1.188
diff -u -p -u -r1.188 ehci.c
--- ehci.c 15 Mar 2012 18:38:37 -0000 1.188
+++ ehci.c 16 Mar 2012 07:50:28 -0000
@@ -2712,12 +2712,12 @@ ehci_alloc_sqtd_chain(struct ehci_pipe *
ehci_physaddr_t a = dataphys + i * EHCI_PAGE_SIZE;
if (i != 0) /* use offset only in first buffer */
a = EHCI_PAGE(a);
-#ifdef DIAGNOSTIC
if (i >= EHCI_QTD_NBUFFERS) {
+#ifdef DIAGNOSTIC
printf("ehci_alloc_sqtd_chain: i=%d\n", i);
+#endif
goto nomem;
}
-#endif
cur->qtd.qtd_buffer[i] = htole32(a);
cur->qtd.qtd_buffer_hi[i] = 0;
}
I agree it would be better.
If you mean something else I don't understand :)
--
Manuel Bouyer <bou...@antioche.eu.org>
NetBSD: 26 ans d'experience feront toujours la difference
--
