Commit d80771c0 authored by Leonard Crestez's avatar Leonard Crestez Committed by Herbert Xu
Browse files

crypto: mxs-dcp - Fix wait logic on chan threads 



When compiling with CONFIG_DEBUG_ATOMIC_SLEEP=y the mxs-dcp driver
prints warnings such as:

WARNING: CPU: 0 PID: 120 at kernel/sched/core.c:7736 __might_sleep+0x98/0x9c
do not call blocking ops when !TASK_RUNNING; state=1 set at [<8081978c>] dcp_chan_thread_sha+0x3c/0x2ec

The problem is that blocking ops will manipulate current->state
themselves so it is not allowed to call them between
set_current_state(TASK_INTERRUPTIBLE) and schedule().

Fix this by converting the per-chan mutex to a spinlock (it only
protects tiny list ops anyway) and rearranging the wait logic so that
callbacks are called current->state as TASK_RUNNING. Those callbacks
will indeed call blocking ops themselves so this is required.

Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarLeonard Crestez <leonard.crestez@nxp.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent add92a81

drivers/crypto/mxs-dcp.c

+30 −23
Original line number Diff line number Diff line
@@ -63,7 +63,7 @@ struct dcp { 
	struct dcp_coherent_block	*coh;



	struct completion		completion[DCP_MAX_CHANS];

	struct mutex			mutex[DCP_MAX_CHANS];

	spinlock_t			lock[DCP_MAX_CHANS];

	struct task_struct		*thread[DCP_MAX_CHANS];

	struct crypto_queue		queue[DCP_MAX_CHANS];

};
@@ -349,13 +349,20 @@ static int dcp_chan_thread_aes(void *data) 


	int ret;



	do {

		__set_current_state(TASK_INTERRUPTIBLE);

	while (!kthread_should_stop()) {

		set_current_state(TASK_INTERRUPTIBLE);



		mutex_lock(&sdcp->mutex[chan]);

		spin_lock(&sdcp->lock[chan]);

		backlog = crypto_get_backlog(&sdcp->queue[chan]);

		arq = crypto_dequeue_request(&sdcp->queue[chan]);

		mutex_unlock(&sdcp->mutex[chan]);

		spin_unlock(&sdcp->lock[chan]);



		if (!backlog && !arq) {

			schedule();

			continue;

		}



		set_current_state(TASK_RUNNING);



		if (backlog)

			backlog->complete(backlog, -EINPROGRESS);
@@ -363,11 +370,8 @@ static int dcp_chan_thread_aes(void *data) 
		if (arq) {

			ret = mxs_dcp_aes_block_crypt(arq);

			arq->complete(arq, ret);

			continue;

		}



		schedule();

	} while (!kthread_should_stop());

	}



	return 0;

}
@@ -409,9 +413,9 @@ static int mxs_dcp_aes_enqueue(struct ablkcipher_request *req, int enc, int ecb) 
	rctx->ecb = ecb;

	actx->chan = DCP_CHAN_CRYPTO;



	mutex_lock(&sdcp->mutex[actx->chan]);

	spin_lock(&sdcp->lock[actx->chan]);

	ret = crypto_enqueue_request(&sdcp->queue[actx->chan], &req->base);

	mutex_unlock(&sdcp->mutex[actx->chan]);

	spin_unlock(&sdcp->lock[actx->chan]);



	wake_up_process(sdcp->thread[actx->chan]);
@@ -640,13 +644,20 @@ static int dcp_chan_thread_sha(void *data) 
	struct ahash_request *req;

	int ret, fini;



	do {

		__set_current_state(TASK_INTERRUPTIBLE);

	while (!kthread_should_stop()) {

		set_current_state(TASK_INTERRUPTIBLE);



		mutex_lock(&sdcp->mutex[chan]);

		spin_lock(&sdcp->lock[chan]);

		backlog = crypto_get_backlog(&sdcp->queue[chan]);

		arq = crypto_dequeue_request(&sdcp->queue[chan]);

		mutex_unlock(&sdcp->mutex[chan]);

		spin_unlock(&sdcp->lock[chan]);



		if (!backlog && !arq) {

			schedule();

			continue;

		}



		set_current_state(TASK_RUNNING);



		if (backlog)

			backlog->complete(backlog, -EINPROGRESS);
@@ -658,12 +669,8 @@ static int dcp_chan_thread_sha(void *data) 
			ret = dcp_sha_req_to_buf(arq);

			fini = rctx->fini;

			arq->complete(arq, ret);

			if (!fini)

				continue;

		}



		schedule();

	} while (!kthread_should_stop());

	}



	return 0;

}
@@ -721,9 +728,9 @@ static int dcp_sha_update_fx(struct ahash_request *req, int fini) 
		rctx->init = 1;

	}



	mutex_lock(&sdcp->mutex[actx->chan]);

	spin_lock(&sdcp->lock[actx->chan]);

	ret = crypto_enqueue_request(&sdcp->queue[actx->chan], &req->base);

	mutex_unlock(&sdcp->mutex[actx->chan]);

	spin_unlock(&sdcp->lock[actx->chan]);



	wake_up_process(sdcp->thread[actx->chan]);

	mutex_unlock(&actx->mutex);
@@ -997,7 +1004,7 @@ static int mxs_dcp_probe(struct platform_device *pdev) 
	platform_set_drvdata(pdev, sdcp);



	for (i = 0; i < DCP_MAX_CHANS; i++) {

		mutex_init(&sdcp->mutex[i]);

		spin_lock_init(&sdcp->lock[i]);

		init_completion(&sdcp->completion[i]);

		crypto_init_queue(&sdcp->queue[i], 50);

	}

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