| Message ID | 20211211085655.30294-1-shenyang39@huawei.com (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Herbert Xu |
| Headers | show |
| Series | crypto: hisilicon/qm - fix deadlock for remove driver | expand |
On Sat, Dec 11, 2021 at 04:56:55PM +0800, Yang Shen wrote: > 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> > --- > drivers/crypto/hisilicon/qm.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) Patch applied. Thanks.
diff --git a/drivers/crypto/hisilicon/qm.c b/drivers/crypto/hisilicon/qm.c index 896255aec87f..bea8622d80e6 100644 --- a/drivers/crypto/hisilicon/qm.c +++ b/drivers/crypto/hisilicon/qm.c @@ -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);
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> --- drivers/crypto/hisilicon/qm.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) -- 2.33.0