Commit 39ce2529 authored by Dmitry Osipenko's avatar Dmitry Osipenko
Browse files

drm: Assert held reservation lock for dma-buf mmapping 



When userspace mmaps dma-buf's fd, the dma-buf reservation lock must be
held. Add locking sanity checks to the dma-buf mmaping callbacks of DRM
drivers to ensure that the locking assumptions won't regress in future.

Suggested-by: default avatarDaniel Vetter <daniel@ffwll.ch>
Signed-off-by: default avatarDmitry Osipenko <dmitry.osipenko@collabora.com>
Acked-by: default avatarChristian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221110201349.351294-3-dmitry.osipenko@collabora.com
parent 8526e973

drivers/gpu/drm/drm_prime.c

+2 −0
Original line number Diff line number Diff line
@@ -781,6 +781,8 @@ int drm_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct *vma) 
	struct drm_gem_object *obj = dma_buf->priv;

	struct drm_device *dev = obj->dev;



	dma_resv_assert_held(dma_buf->resv);



	if (!dev->driver->gem_prime_mmap)

		return -ENOSYS;

drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c

+2 −0
Original line number Diff line number Diff line
@@ -97,6 +97,8 @@ static int i915_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct * 
	struct drm_i915_private *i915 = to_i915(obj->base.dev);

	int ret;



	dma_resv_assert_held(dma_buf->resv);



	if (obj->base.size < vma->vm_end - vma->vm_start)

		return -EINVAL;

drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c

+2 −0
Original line number Diff line number Diff line
@@ -66,6 +66,8 @@ static int omap_gem_dmabuf_mmap(struct dma_buf *buffer, 
	struct drm_gem_object *obj = buffer->priv;

	int ret = 0;



	dma_resv_assert_held(buffer->resv);



	ret = drm_gem_mmap_obj(obj, omap_gem_mmap_size(obj), vma);

	if (ret < 0)

		return ret;

drivers/gpu/drm/tegra/gem.c

+2 −0
Original line number Diff line number Diff line
@@ -694,6 +694,8 @@ static int tegra_gem_prime_mmap(struct dma_buf *buf, struct vm_area_struct *vma) 
	struct drm_gem_object *gem = buf->priv;

	int err;



	dma_resv_assert_held(buf->resv);



	err = drm_gem_mmap_obj(gem, gem->size, vma);

	if (err < 0)

		return err;