On Jun 26, 2013 4:13 PM, "Maarten Lankhorst" <<a href="mailto:maarten.lankhorst@canonical.com">maarten.lankhorst@canonical.com</a>> wrote: > > Op 26-06-13 04:14, Seung-Woo Kim schreef: > > From: YoungJun Cho <<a href="mailto:yj44.cho@samsung.com">yj44.cho@samsung.com</a>> > > > > The drm_gem_mmap_obj() has to be protected with dev->struct_mutex, > > but some caller functions do not. So it adds mutex lock to missing > > callers and adds WARN_ON assertion whether drm_gem_mmap_obj() is > > called with mutex lock or not. > > > > Signed-off-by: YoungJun Cho <<a href="mailto:yj44.cho@samsung.com">yj44.cho@samsung.com</a>> > > Signed-off-by: Seung-Woo Kim <<a href="mailto:sw0312.kim@samsung.com">sw0312.kim@samsung.com</a>> > > Signed-off-by: Kyungmin Park <<a href="mailto:kyungmin.park@samsung.com">kyungmin.park@samsung.com</a>> > > CC: Laurent Pinchart <<a href="mailto:laurent.pinchart%2Brenesas@ideasonboard.com">laurent.pinchart+renesas@ideasonboard.com</a>> > > CC: Rob Clark <<a href="mailto:robdclark@gmail.com">robdclark@gmail.com</a>> > > --- > > This patch is based on drm-next branch. > > > > drivers/gpu/drm/drm_gem.c | 4 ++++ > > drivers/gpu/drm/drm_gem_cma_helper.c | 3 +++ > > drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c | 3 +++ > > 3 files changed, 10 insertions(+), 0 deletions(-) > > > > diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c > > index 4321713..b19bba0 100644 > > --- a/drivers/gpu/drm/drm_gem.c > > +++ b/drivers/gpu/drm/drm_gem.c > > @@ -661,6 +661,8 @@ EXPORT_SYMBOL(drm_gem_vm_close); > > * the GEM object is not looked up based on its fake offset. To implement the > > * DRM mmap operation, drivers should use the drm_gem_mmap() function. > > * > > + * NOTE: This function has to be protected with dev->struct_mutex > > + * > > * Return 0 or success or -EINVAL if the object size is smaller than the VMA > > * size, or if no gem_vm_ops are provided. > > */ > > @@ -669,6 +671,8 @@ int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size, > > { > > struct drm_device *dev = obj->dev; > > > > + WARN_ON(!mutex_is_locked(&dev->struct_mutex)); > > > Please don't use mutex_is_locked, use lockdep_assert_held, so the cost only exists when PROVE_LOCKING is used.. > > I know some current code does it wrong, but that is the correct function to use. > > ~Maarten > Thank you for nice comments! I will update it again. Best regards YJ _______________________________________________ > dri-devel mailing list > <a href="mailto:dri-devel@lists.freedesktop.org">dri-devel@lists.freedesktop.org</a> > <a href="http://lists.freedesktop.org/mailman/listinfo/dri-devel">http://lists.freedesktop.org/mailman/listinfo/dri-devel</a>