OK julia On Fri, 19 Dec 2008, Eric Anholt wrote: > On Sat, 2008-12-20 at 08:35 +1000, Dave Airlie wrote: > > On Sat, Dec 20, 2008 at 3:10 AM, Julia Lawall <julia@xxxxxxx> wrote: > > > From: Julia Lawall <julia@xxxxxxx> > > > > > > If the NULL test is necessary, then the dereference should be moved below > > > the NULL test. > > > > > > The semantic patch that makes this change is as follows: > > > (http://www.emn.fr/x-info/coccinelle/). The result has been modified to > > > move the initialization of driver down closer to where it is used. > > > > > > // <smpl> > > > @@ > > > type T; > > > expression E; > > > identifier i,fld; > > > statement S; > > > @@ > > > > > > - T i = E->fld; > > > + T i; > > > ... when != E > > > when != i > > > if (E == NULL) S > > > + i = E->fld; > > > // </smpl> > > > > > > Signed-off-by: Julia Lawall <julia@xxxxxxx> > > > > > > --- > > > drivers/gpu/drm/drm_drv.c | 7 ++++--- > > > 1 file changed, 4 insertions(+), 3 deletions(-) > > > > > > diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c > > > index 0b9f316..4bdfc98 100644 > > > --- a/drivers/gpu/drm/drm_drv.c > > > +++ b/drivers/gpu/drm/drm_drv.c > > > @@ -297,7 +297,7 @@ EXPORT_SYMBOL(drm_init); > > > */ > > > static void drm_cleanup(struct drm_device * dev) > > > { > > > - struct drm_driver *driver = dev->driver; > > > + struct drm_driver *driver; > > > > > > DRM_DEBUG("\n"); > > > > > > @@ -324,8 +324,9 @@ static void drm_cleanup(struct drm_device * dev) > > > dev->agp = NULL; > > > } > > > > > > - if (dev->driver->unload) > > > - dev->driver->unload(dev); > > > + driver = dev->driver; > > > + if (driver->unload) > > > + driver->unload(dev); > > > > Huh? > > > > The original test is to check it dev->driver->unload exists, not it > > dev->driver exists. > > > > I think your test parameters are wrong. > > No, it was valid, but I think the better patch is: > > From 1e0a24cfe75a328db5a50dbcdaaf0eb461638b6b Mon Sep 17 00:00:00 2001 > From: Eric Anholt <eric@xxxxxxxxxx> > Date: Fri, 19 Dec 2008 15:07:11 -0800 > Subject: [PATCH] drm: Avoid use-before-null-test on dev in drm_cleanup(). > > Signed-off-by: Eric Anholt <eric@xxxxxxxxxx> > > --- > drivers/gpu/drm/drm_drv.c | 4 +--- > 1 files changed, 1 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c > index 373e3de..febb517 100644 > --- a/drivers/gpu/drm/drm_drv.c > +++ b/drivers/gpu/drm/drm_drv.c > @@ -294,8 +294,6 @@ EXPORT_SYMBOL(drm_init); > */ > static void drm_cleanup(struct drm_device * dev) > { > - struct drm_driver *driver = dev->driver; > - > DRM_DEBUG("\n"); > > if (!dev) { > @@ -330,7 +328,7 @@ static void drm_cleanup(struct drm_device * dev) > if (drm_core_check_feature(dev, DRIVER_MODESET)) > drm_put_minor(&dev->control); > > - if (driver->driver_features & DRIVER_GEM) > + if (dev->driver->driver_features & DRIVER_GEM) > drm_gem_destroy(dev); > > drm_put_minor(&dev->primary); > -- > 1.5.6.5 > > > -- > Eric Anholt > eric@xxxxxxxxxx eric.anholt@xxxxxxxxx > > > -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
