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dmaengine: idxd: move out percpu_ref_exit() to ensure it's outside submission

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[ Upstream commit 85f604af9c83a4656b1d07bec73298c3ba7d7c1e ]

percpu_ref_tryget_live() is safe to call as long as ref is between init and
exit according to the function comment. Move percpu_ref_exit() so it is
called after the dma channel is no longer valid to ensure this holds true.

Fixes: 93a40a6d7428 ("dmaengine: idxd: add percpu_ref to descriptor submission path")
Suggested-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/163294293832.914350.10326422026738506152.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Dave Jiang 2021-09-29 12:15:38 -07:00 committed by Greg Kroah-Hartman
parent c31b0fe8e1
commit 46a2f79455
2 changed files with 2 additions and 1 deletions
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1
drivers/dma/idxd/device.c
View File

@ -427,7 +427,6 @@ void idxd_wq_quiesce(struct idxd_wq *wq)
{
percpu_ref_kill(&wq->wq_active);
wait_for_completion(&wq->wq_dead);
percpu_ref_exit(&wq->wq_active);
}
/* Device control bits */

2
drivers/dma/idxd/dma.c
View File

@ -311,6 +311,7 @@ static int idxd_dmaengine_drv_probe(struct idxd_dev *idxd_dev)
err_dma:
idxd_wq_quiesce(wq);
percpu_ref_exit(&wq->wq_active);
err_ref:
idxd_wq_free_resources(wq);
err_res_alloc:
@ -329,6 +330,7 @@ static void idxd_dmaengine_drv_remove(struct idxd_dev *idxd_dev)
idxd_wq_quiesce(wq);
idxd_unregister_dma_channel(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);