[PATCH 5.15 756/917] dmaengine: idxd: fix resource leak on dmaengine driver disable

From: Greg Kroah-Hartman
Date: Mon Nov 15 2021 - 19:46:46 EST


From: Dave Jiang <dave.jiang@xxxxxxxxx>

[ Upstream commit a3e340c1574b6679f5b333221284d0959095da52 ]

The wq resources needs to be released before the kernel type is reset by
__drv_disable_wq(). With dma channels unregistered and wq quiesced, all the
wq resources for dmaengine can be freed. There is no need to wait until wq
is disabled. With the wq->type being reset to "unknown", the driver is
skipping the freeing of the resources.

Fixes: 0cda4f6986a3 ("dmaengine: idxd: create dmaengine driver for wq 'device'")
Reported-by: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
Tested-by: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx>
Link: https://lore.kernel.org/r/163517405099.3484556.12521975053711345244.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/dma/idxd/dma.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/dma/idxd/dma.c b/drivers/dma/idxd/dma.c
index b90b085d18cff..c39e9483206ad 100644
--- a/drivers/dma/idxd/dma.c
+++ b/drivers/dma/idxd/dma.c
@@ -329,10 +329,9 @@ static void idxd_dmaengine_drv_remove(struct idxd_dev *idxd_dev)
mutex_lock(&wq->wq_lock);
idxd_wq_quiesce(wq);
idxd_unregister_dma_channel(wq);
+ idxd_wq_free_resources(wq);
__drv_disable_wq(wq);
percpu_ref_exit(&wq->wq_active);
- idxd_wq_free_resources(wq);
- wq->type = IDXD_WQT_NONE;
mutex_unlock(&wq->wq_lock);
}

--
2.33.0