diff options
| author | Yang Shen <shenyang39@huawei.com> | 2021-12-11 16:56:55 +0800 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2021-12-17 16:59:48 +1100 |
| commit | fc6c01f0cd10b89c4b01dd2940e0b0cda1bd82fb (patch) | |
| tree | 9d870be6ee65ec56e6a7ddb09efdc570f16baf0f /drivers/crypto | |
| parent | 808957baf3aa42b71453c8accc71cf5e52665982 (diff) | |
| download | lwn-fc6c01f0cd10b89c4b01dd2940e0b0cda1bd82fb.tar.gz lwn-fc6c01f0cd10b89c4b01dd2940e0b0cda1bd82fb.zip | |
crypto: hisilicon/qm - fix deadlock for remove driver
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>
Diffstat (limited to 'drivers/crypto')
| -rw-r--r-- | drivers/crypto/hisilicon/qm.c | 3 |
1 files changed, 1 insertions, 2 deletions
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); |