[PATCH 5.15 156/207] drm/msm: Fix wait_fence submitqueue leak

Greg Kroah-Hartman
2021-12-06T15:59:55Z

From: Rob Clark <robdclark@chromium.org>

[ Upstream commit ea0006d390a28012f8187717aea61498b2b341e5 ]

We weren't dropping the submitqueue reference in all paths. In
particular, when the fence has already been signalled. Split out
a helper to simplify handling this in the various different return
paths.

Fixes: a61acbbe9cf8 ("drm/msm: Track "seqno" fences by idr")
Signed-off-by: Rob Clark <robdclark@chromium.org>
Link: https://lore.kernel.org/r/20211111192457.747899-2-robdclark@gmail.com
Signed-off-by: Rob Clark <robdclark@chromium.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/msm/msm_drv.c | 49 +++++++++++++++++++++--------------
1 file changed, 29 insertions(+), 20 deletions(-)

diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index d4e09703a87db..4c5661f38dd26 100644
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -938,29 +938,12 @@ static int msm_ioctl_gem_info(struct drm_device *dev, void *data,
return ret;
}

-static int msm_ioctl_wait_fence(struct drm_device *dev, void *data,
- struct drm_file *file)
+static int wait_fence(struct msm_gpu_submitqueue *queue, uint32_t fence_id,
+ ktime_t timeout)
{
- struct msm_drm_private *priv = dev->dev_private;
- struct drm_msm_wait_fence *args = data;
- ktime_t timeout = to_ktime(args->timeout);
- struct msm_gpu_submitqueue *queue;
- struct msm_gpu *gpu = priv->gpu;
struct dma_fence *fence;
int ret;

- if (args->pad) {
- DRM_ERROR("invalid pad: %08x\n", args->pad);
- return -EINVAL;
- }
-
- if (!gpu)
- return 0;
-
- queue = msm_submitqueue_get(file->driver_priv, args->queueid);
- if (!queue)
- return -ENOENT;
-
/*
* Map submitqueue scoped "seqno" (which is actually an idr key)
* back to underlying dma-fence
@@ -972,7 +955,7 @@ static int msm_ioctl_wait_fence(struct drm_device *dev, void *data,
ret = mutex_lock_interruptible(&queue->lock);
if (ret)
return ret;
- fence = idr_find(&queue->fence_idr, args->fence);
+ fence = idr_find(&queue->fence_idr, fence_id);
if (fence)
fence = dma_fence_get_rcu(fence);
mutex_unlock(&queue->lock);
@@ -988,6 +971,32 @@ static int msm_ioctl_wait_fence(struct drm_device *dev, void *data,
}

dma_fence_put(fence);
+
+ return ret;
+}
+
+static int msm_ioctl_wait_fence(struct drm_device *dev, void *data,
+ struct drm_file *file)
+{
+ struct msm_drm_private *priv = dev->dev_private;
+ struct drm_msm_wait_fence *args = data;
+ struct msm_gpu_submitqueue *queue;
+ int ret;
+
+ if (args->pad) {
+ DRM_ERROR("invalid pad: %08x\n", args->pad);
+ return -EINVAL;
+ }
+
+ if (!priv->gpu)
+ return 0;
+
+ queue = msm_submitqueue_get(file->driver_priv, args->queueid);
+ if (!queue)
+ return -ENOENT;
+
+ ret = wait_fence(queue, args->fence, to_ktime(args->timeout));
+
msm_submitqueue_put(queue);

return ret;
--
2.33.0