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From:   =?UTF-8?q?D=C4=81vis=20Mos=C4=81ns?= <davispuh@gmail.com>
To:     linux-kernel@vger.kernel.org
Cc:     Tom Lendacky <thomas.lendacky@amd.com>,
        John Allen <john.allen@amd.com>, linux-crypto@vger.kernel.org,
        dmaengine@vger.kernel.org,
        =?UTF-8?q?D=C4=81vis=20Mos=C4=81ns?= <davispuh@gmail.com>
Subject: [PATCH] ccp: ccp_dmaengine_unregister release dma channels
Date:   Mon, 28 Feb 2022 05:15:45 +0200
Message-Id: <20220228031545.11639-1-davispuh@gmail.com>
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Precedence: bulk

ccp_dmaengine_register adds dma_chan->device_node to dma_dev->channels list
but ccp_dmaengine_unregister didn't remove them.
That can cause crashes in various dmaengine methods that tries to use dma_dev->channels

Signed-off-by: Dāvis Mosāns <davispuh@gmail.com>
---
 drivers/crypto/ccp/ccp-dmaengine.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/crypto/ccp/ccp-dmaengine.c b/drivers/crypto/ccp/ccp-dmaengine.c
index d718db224be42..7d4b4ad1db1f3 100644
--- a/drivers/crypto/ccp/ccp-dmaengine.c
+++ b/drivers/crypto/ccp/ccp-dmaengine.c
@@ -632,6 +632,20 @@ static int ccp_terminate_all(struct dma_chan *dma_chan)
 	return 0;
 }
 
+static void ccp_dma_release(struct ccp_device *ccp)
+{
+	struct ccp_dma_chan *chan;
+	struct dma_chan *dma_chan;
+	unsigned int i;
+
+	for (i = 0; i < ccp->cmd_q_count; i++) {
+		chan = ccp->ccp_dma_chan + i;
+		dma_chan = &chan->dma_chan;
+		tasklet_kill(&chan->cleanup_tasklet);
+		list_del_rcu(&dma_chan->device_node);
+	}
+}
+
 int ccp_dmaengine_register(struct ccp_device *ccp)
 {
 	struct ccp_dma_chan *chan;
@@ -736,6 +750,7 @@ int ccp_dmaengine_register(struct ccp_device *ccp)
 	return 0;
 
 err_reg:
+	ccp_dma_release(ccp);
 	kmem_cache_destroy(ccp->dma_desc_cache);
 
 err_cache:
@@ -752,6 +767,7 @@ void ccp_dmaengine_unregister(struct ccp_device *ccp)
 		return;
 
 	dma_async_device_unregister(dma_dev);
+	ccp_dma_release(ccp);
 
 	kmem_cache_destroy(ccp->dma_desc_cache);
 	kmem_cache_destroy(ccp->dma_cmd_cache);
-- 
2.35.1