The Parfait (version 2.1.0) static code analysis tool found the following NULL pointer derefernce problem.
- drivers/gpu/drm/drm_vblank.c Null pointer checks were added to return values from calls to drm_crtc_from_index(). There is a possibility, however minute, that crtc->index may not be found when trying to find the struct crtc from it's assigned index given in drm_crtc_init_with_planes(). 3 return checks for NULL where added with a call to WARN_ON(!crtc).
Signed-off-by: Joe Moriarty joe.moriarty@oracle.com Reviewed-by: Steven Sistare steven.sistare@oracle.com --- drivers/gpu/drm/drm_vblank.c | 9 +++++++++ 1 file changed, 9 insertions(+)
diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c index 32d9bcf5be7f..03b431eb47ae 100644 --- a/drivers/gpu/drm/drm_vblank.c +++ b/drivers/gpu/drm/drm_vblank.c @@ -120,6 +120,9 @@ static u32 __get_vblank_counter(struct drm_device *dev, unsigned int pipe) if (drm_core_check_feature(dev, DRIVER_MODESET)) { struct drm_crtc *crtc = drm_crtc_from_index(dev, pipe);
+ if (WARN_ON(!crtc)) + return 0; + if (crtc->funcs->get_vblank_counter) return crtc->funcs->get_vblank_counter(crtc); } @@ -318,6 +321,9 @@ static void __disable_vblank(struct drm_device *dev, unsigned int pipe) if (drm_core_check_feature(dev, DRIVER_MODESET)) { struct drm_crtc *crtc = drm_crtc_from_index(dev, pipe);
+ if (WARN_ON(!crtc)) + return; + if (crtc->funcs->disable_vblank) { crtc->funcs->disable_vblank(crtc); return; @@ -918,6 +924,9 @@ static int __enable_vblank(struct drm_device *dev, unsigned int pipe) if (drm_core_check_feature(dev, DRIVER_MODESET)) { struct drm_crtc *crtc = drm_crtc_from_index(dev, pipe);
+ if (WARN_ON(!crtc)) + return 0; + if (crtc->funcs->enable_vblank) return crtc->funcs->enable_vblank(crtc); }