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crypto: hisilicon/qm - fix deadlock for remove driver

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When remove the driver and executing the task occur at the same time,
the following deadlock will be triggered:

Chain exists of:
    sva_lock --> uacce_mutex --> &qm->qps_lock
    Possible unsafe locking scenario:
		CPU0                    CPU1
		----                    ----
	lock(&qm->qps_lock);
					lock(uacce_mutex);
					lock(&qm->qps_lock);
	lock(sva_lock);

And the lock 'qps_lock' is used to protect qp. Therefore, it's reasonable
cycle is to continue until the qp memory is released. So move the release
lock infront of 'uacce_remove'.

Signed-off-by: Yang Shen <shenyang39@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Yang Shen
2021-12-11 16:56:55 +08:00
committed by Herbert Xu
parent 808957baf3
commit fc6c01f0cd
1 changed files with 1 additions and 2 deletions
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3
drivers/crypto/hisilicon/qm.c
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@@ -3425,6 +3425,7 @@ void hisi_qm_uninit(struct hisi_qm *qm)
dma_free_coherent(dev, qm->qdma.size,
qm->qdma.va, qm->qdma.dma);
}
up_write(&qm->qps_lock);
qm_irq_unregister(qm);
hisi_qm_pci_uninit(qm);
@@ -3432,8 +3433,6 @@ void hisi_qm_uninit(struct hisi_qm *qm)
uacce_remove(qm->uacce);
qm->uacce = NULL;
}
up_write(&qm->qps_lock);
}
EXPORT_SYMBOL_GPL(hisi_qm_uninit);