[PATCH 5.1 83/85] drm/cma-helper: Fix drm_gem_cma_free_object()

From: Greg Kroah-Hartman
Date: Fri Jun 07 2019 - 11:54:54 EST


From: Noralf TrÃnnes <noralf@xxxxxxxxxxx>

commit 23e35c0eb81a23d40c079a7eb187fc321fa1deb7 upstream.

The logic for freeing an imported buffer with a virtual address is
broken. It will free the buffer instead of unmapping the dma buf.
Fix by reversing the if ladder and first check if the buffer is imported.

Fixes: b9068cde51ee ("drm/cma-helper: Add DRM_GEM_CMA_VMAP_DRIVER_OPS")
Cc: stable@xxxxxxxxxxxxxxx
Reported-by: "Li, Tingqian" <tingqian.li@xxxxxxxxx>
Signed-off-by: Noralf TrÃnnes <noralf@xxxxxxxxxxx>
Reviewed-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20190426124753.53722-1-noralf@xxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/gpu/drm/drm_gem_cma_helper.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

--- a/drivers/gpu/drm/drm_gem_cma_helper.c
+++ b/drivers/gpu/drm/drm_gem_cma_helper.c
@@ -186,13 +186,13 @@ void drm_gem_cma_free_object(struct drm_

cma_obj = to_drm_gem_cma_obj(gem_obj);

- if (cma_obj->vaddr) {
- dma_free_wc(gem_obj->dev->dev, cma_obj->base.size,
- cma_obj->vaddr, cma_obj->paddr);
- } else if (gem_obj->import_attach) {
+ if (gem_obj->import_attach) {
if (cma_obj->vaddr)
dma_buf_vunmap(gem_obj->import_attach->dmabuf, cma_obj->vaddr);
drm_prime_gem_destroy(gem_obj, cma_obj->sgt);
+ } else if (cma_obj->vaddr) {
+ dma_free_wc(gem_obj->dev->dev, cma_obj->base.size,
+ cma_obj->vaddr, cma_obj->paddr);
}

drm_gem_object_release(gem_obj);