On Fri, Oct 21, 2016 at 10:22:04AM -0400, Alex Deucher wrote: > On Fri, Oct 21, 2016 at 10:15 AM, Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> wrote: > > We have reached the era where monitor bandwidths now exceed 31bits in > > frequency calculations, though as we stored them in kHz units we are > > safe from overflow in the modelines for some time. > > > > [ 48.723720] UBSAN: Undefined behaviour in ../drivers/gpu/drm/drm_modes.c:325:49 > > [ 48.726943] signed integer overflow: > > [ 48.728503] 2240 * 1000000 cannot be represented in type 'int' > > > > Reported-by: Martin Liška <marxin.liska@xxxxxxxxx> > > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=98372 > > Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > > Reviewed-by: Alex Deucher <alexander.deucher@xxxxxxx> Applied to drm-misc. -Daniel > > > --- > > drivers/gpu/drm/drm_modes.c | 8 ++++++-- > > 1 file changed, 6 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c > > index 173b7d335834..f64ac86deb84 100644 > > --- a/drivers/gpu/drm/drm_modes.c > > +++ b/drivers/gpu/drm/drm_modes.c > > @@ -165,6 +165,7 @@ struct drm_display_mode *drm_cvt_mode(struct drm_device *dev, int hdisplay, > > unsigned int vfieldrate, hperiod; > > int hdisplay_rnd, hmargin, vdisplay_rnd, vmargin, vsync; > > int interlace; > > + u64 tmp; > > > > /* allocate the drm_display_mode structure. If failure, we will > > * return directly > > @@ -322,8 +323,11 @@ struct drm_display_mode *drm_cvt_mode(struct drm_device *dev, int hdisplay, > > drm_mode->vsync_end = drm_mode->vsync_start + vsync; > > } > > /* 15/13. Find pixel clock frequency (kHz for xf86) */ > > - drm_mode->clock = drm_mode->htotal * HV_FACTOR * 1000 / hperiod; > > - drm_mode->clock -= drm_mode->clock % CVT_CLOCK_STEP; > > + tmp = drm_mode->htotal; /* perform intermediate calcs in u64 */ > > + tmp *= HV_FACTOR * 1000; > > + do_div(tmp, hperiod); > > + tmp -= drm_mode->clock % CVT_CLOCK_STEP; > > + drm_mode->clock = tmp; > > /* 18/16. Find actual vertical frame frequency */ > > /* ignore - just set the mode flag for interlaced */ > > if (interlaced) { > > -- > > 2.9.3 > > > > _______________________________________________ > > dri-devel mailing list > > dri-devel@xxxxxxxxxxxxxxxxxxxxx > > https://lists.freedesktop.org/mailman/listinfo/dri-devel > _______________________________________________ > dri-devel mailing list > dri-devel@xxxxxxxxxxxxxxxxxxxxx > https://lists.freedesktop.org/mailman/listinfo/dri-devel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
