[PATCH] drm/imagination: Move dereference after NULL check in pvr_mmu_backing_page_init()

From: Dan Carpenter
Date: Wed Dec 06 2023 - 09:37:34 EST


This code dereferences "page->pvr_dev" and then checked for NULL on the
next line. Re-order it to avoid a potential NULL pointer dereference.

Fixes: ff5f643de0bf ("drm/imagination: Add GEM and VM related code")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
---
drivers/gpu/drm/imagination/pvr_mmu.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/imagination/pvr_mmu.c b/drivers/gpu/drm/imagination/pvr_mmu.c
index c8562bfc0dcd..4fe70610ed94 100644
--- a/drivers/gpu/drm/imagination/pvr_mmu.c
+++ b/drivers/gpu/drm/imagination/pvr_mmu.c
@@ -316,12 +316,14 @@ pvr_mmu_backing_page_init(struct pvr_mmu_backing_page *page,
static void
pvr_mmu_backing_page_fini(struct pvr_mmu_backing_page *page)
{
- struct device *dev = from_pvr_device(page->pvr_dev)->dev;
+ struct device *dev;

/* Do nothing if no allocation is present. */
if (!page->pvr_dev)
return;

+ dev = from_pvr_device(page->pvr_dev)->dev;
+
dma_unmap_page(dev, page->dma_addr, PVR_MMU_BACKING_PAGE_SIZE,
DMA_TO_DEVICE);

--
2.42.0