[PATCHv3 14/14] mailbox: call request_irq after mbox queues are allocated

[Suman Anna]

The mailbox startup code is enabling the interrupt even before
any of the associated mailbox queues are allocated. Any pending
received mailbox message could cause a kernel panic as soon as
the interrupt is enabled due to the dereferencing of non-existing
mailbox queues within the ISR.

Signed-off-by: Fernando Guzman Lugo <lugo.fernando at gmail.com>
Signed-off-by: Suman Anna <s-anna at ti.com>
---
 drivers/mailbox/mailbox.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/drivers/mailbox/mailbox.c b/drivers/mailbox/mailbox.c
index c38241a..5fea5c2 100644
--- a/drivers/mailbox/mailbox.c
+++ b/drivers/mailbox/mailbox.c
@@ -377,14 +377,6 @@ static int mailbox_startup(struct mailbox *mbox)
 	}
 
 	if (!mbox->use_count++) {
-		ret = request_irq(mbox->irq, mbox_interrupt,
-				IRQF_SHARED | IRQF_NO_SUSPEND,
-				mbox->name, mbox);
-		if (unlikely(ret)) {
-			pr_err("failed to register mailbox interrupt:%d\n",
-					ret);
-			goto fail_request_irq;
-		}
 		mq = mbox_queue_alloc(mbox, NULL, mbox_tx_tasklet);
 		if (!mq) {
 			ret = -ENOMEM;
@@ -399,17 +391,25 @@ static int mailbox_startup(struct mailbox *mbox)
 		}
 		mbox->rxq = mq;
 		mq->mbox = mbox;
+		ret = request_irq(mbox->irq, mbox_interrupt,
+				IRQF_SHARED | IRQF_NO_SUSPEND,
+				mbox->name, mbox);
+		if (unlikely(ret)) {
+			pr_err("failed to register mailbox interrupt:%d\n",
+					ret);
+			goto fail_request_irq;
+		}
 
 		mailbox_enable_irq(mbox, IRQ_RX);
 	}
 	mutex_unlock(&mbox_configured_lock);
 	return 0;
 
+fail_request_irq:
+	mbox_queue_free(mbox->rxq);
 fail_alloc_rxq:
 	mbox_queue_free(mbox->txq);
 fail_alloc_txq:
-	free_irq(mbox->irq, mbox);
-fail_request_irq:
 	if (mbox->ops->shutdown)
 		mbox->ops->shutdown(mbox);
 	mbox->use_count--;
-- 
1.8.1.2