Re: PR/45872 CVS commit: src/sys/dev/usb

[Pierre Pronchery <khorben%defora.org@localhost>]

                        Hi there,

working again on PR/45872, I would like to commit the patch below.

> 2. Division by zero
> -------------------

I have confirmed this issue to be correct, although not happening on a 
regular kernel because GCC optimizes away at -O2. I believe this patch 
would fix it for real.

Additionally, tpcalib_reset() does not fully (re-)initialize the relevant 
data, as uninitialized or outdated data can be returned through the 
WSMOUSEIO_GCALIBCOORDS ioctl; this patch should fix this too.

Let me know if I can commit this:

Index: sys/dev/wscons/tpcalib.c
===================================================================
RCS file: /cvsroot/src/sys/dev/wscons/tpcalib.c,v
retrieving revision 1.11
diff -p -u -r1.11 tpcalib.c
--- sys/dev/wscons/tpcalib.c    4 Mar 2007 06:02:51 -0000       1.11
+++ sys/dev/wscons/tpcalib.c    11 Oct 2012 23:54:24 -0000
@@ -65,7 +65,9 @@ tpcalib_init(struct tpcalib_softc *sc)
 void
 tpcalib_reset(struct tpcalib_softc *sc)
 {
-       /* This indicate 'raw mode'. No translation will be done. */
+       memset(&sc->sc_saved, 0, sizeof(sc->sc_saved));
+
+       /* This indicates 'raw mode'. No translation will be done. */
        sc->sc_saved.samplelen = WSMOUSE_CALIBCOORDS_RESET;
 }
 
Index: sys/dev/wscons/mra.c
===================================================================
RCS file: /cvsroot/src/sys/dev/wscons/mra.c,v
retrieving revision 1.4
diff -p -u -r1.4 mra.c
--- sys/dev/wscons/mra.c        9 Oct 2006 10:43:01 -0000       1.4
+++ sys/dev/wscons/mra.c        11 Oct 2012 23:54:24 -0000
@@ -59,8 +59,13 @@ mra_Y_AX1_BX2_C(const int *y, int ys,
 #define X2(i)          AA(x2, x2s, i)
 #define Y(i)           AA(y, ys, i)
 
+       /* avoid any division by zero later */
+       if (n == 0) {
+               return -1;
+       }
+
        /*
-        * get avarage and sum
+        * get average and sum
         */
        X1a = 0;        X2a = 0;        Ya = 0;
        X1X1s = 0;      X2X2s = 0;      X1X2s = 0;

Cheers,
-- 
khorben