2024-05-02 22:34:07

by Kees Cook

[permalink] [raw]
Subject: [PATCH 2/5] drm/vmwgfx: Do not directly manipulate file->f_count

The correct helper for taking an f_count reference is get_file().
Now that it checks for 0 counts, use it and check results.

Signed-off-by: Kees Cook <[email protected]>
---
Cc: Zack Rusin <[email protected]>
Cc: Broadcom internal kernel review list <[email protected]>
Cc: Maarten Lankhorst <[email protected]>
Cc: Maxime Ripard <[email protected]>
Cc: Thomas Zimmermann <[email protected]>
Cc: David Airlie <[email protected]>
Cc: Daniel Vetter <[email protected]>
Cc: [email protected]
---
drivers/gpu/drm/vmwgfx/ttm_object.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/vmwgfx/ttm_object.c b/drivers/gpu/drm/vmwgfx/ttm_object.c
index 6806c05e57f6..68d8ee3020b1 100644
--- a/drivers/gpu/drm/vmwgfx/ttm_object.c
+++ b/drivers/gpu/drm/vmwgfx/ttm_object.c
@@ -475,7 +475,7 @@ void ttm_object_device_release(struct ttm_object_device **p_tdev)
*/
static bool __must_check get_dma_buf_unless_doomed(struct dma_buf *dmabuf)
{
- return atomic_long_inc_not_zero(&dmabuf->file->f_count) != 0L;
+ return get_file(dmabuf->file) != NULL;
}

/**
--
2.34.1