diff mbox series

[01/10] Revert "drm/msm: Add missing check and destroy for alloc_ordered_workqueue"

Message ID 20230306100722.28485-2-johan+linaro@kernel.org
State New
Headers
Series drm/msm: fix bind error handling |

Commit Message

Johan Hovold March 6, 2023, 10:07 a.m. UTC 
  This reverts commit 643b7d0869cc7f1f7a5ac7ca6bd25d88f54e31d0.

A recent patch that tried to fix up the msm_drm_init() paths with
respect to the workqueue but only ended up making things worse:

First, the newly added calls to msm_drm_uninit() on early errors would
trigger NULL-pointer dereferences, for example, as the kms pointer would
not have been initialised. (Note that these paths were also modified by
a second broken error handling patch which in effect cancelled out this
part when merged.)

Second, the newly added allocation sanity check would still leak the
previously allocated drm device.

Instead of trying to salvage what was badly broken (and clearly not
tested), let's revert the bad commit so that clean and backportable
fixes can be added in its place.

Fixes: 643b7d0869cc ("drm/msm: Add missing check and destroy for alloc_ordered_workqueue")
Cc: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
 drivers/gpu/drm/msm/msm_drv.c | 2 --
 1 file changed, 2 deletions(-)

Comments

Dmitry Baryshkov March 28, 2023, 12:49 p.m. UTC | #1 
On 06/03/2023 12:07, Johan Hovold wrote:
> This reverts commit 643b7d0869cc7f1f7a5ac7ca6bd25d88f54e31d0.
> 
> A recent patch that tried to fix up the msm_drm_init() paths with
> respect to the workqueue but only ended up making things worse:
> 
> First, the newly added calls to msm_drm_uninit() on early errors would
> trigger NULL-pointer dereferences, for example, as the kms pointer would
> not have been initialised. (Note that these paths were also modified by
> a second broken error handling patch which in effect cancelled out this
> part when merged.)
> 
> Second, the newly added allocation sanity check would still leak the
> previously allocated drm device.
> 
> Instead of trying to salvage what was badly broken (and clearly not
> tested), let's revert the bad commit so that clean and backportable
> fixes can be added in its place.
> 
> Fixes: 643b7d0869cc ("drm/msm: Add missing check and destroy for alloc_ordered_workqueue")
> Cc: Jiasheng Jiang <jiasheng@iscas.ac.cn>
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> ---
>   drivers/gpu/drm/msm/msm_drv.c | 2 --
>   1 file changed, 2 deletions(-)
> 

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
diff mbox series

Patch

diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index aca48c868c14..b7f5a78eadd4 100644
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -420,8 +420,6 @@  static int msm_drm_init(struct device *dev, const struct drm_driver *drv)
 	priv->dev = ddev;
 
 	priv->wq = alloc_ordered_workqueue("msm", 0);
-	if (!priv->wq)
-		return -ENOMEM;
 
 	INIT_LIST_HEAD(&priv->objects);
 	mutex_init(&priv->obj_lock);