[PATCHv4 09/14] remoteproc/omap: Check for undefined mailbox messages

[Tero Kristo <t-kristo@xxxxxx>]

From: Suman Anna <s-anna@xxxxxx>

Add some checks in the mailbox callback function to limit
any processing in the mailbox callback function to only
certain currently valid messages, and drop all the remaining
messages. A debug message is added to print any such invalid
messages when the appropriate trace control is enabled.

Co-developed-by: Subramaniam Chanderashekarapuram <subramaniam.ca@xxxxxx>
Signed-off-by: Subramaniam Chanderashekarapuram <subramaniam.ca@xxxxxx>
Signed-off-by: Suman Anna <s-anna@xxxxxx>
Signed-off-by: Tero Kristo <t-kristo@xxxxxx>
Reviewed-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
---
 drivers/remoteproc/omap_remoteproc.c | 6 ++++++
 drivers/remoteproc/omap_remoteproc.h | 7 +++++++
 2 files changed, 13 insertions(+)

diff --git a/drivers/remoteproc/omap_remoteproc.c b/drivers/remoteproc/omap_remoteproc.c
index 9140c528c416..ebf979e71dfd 100644
--- a/drivers/remoteproc/omap_remoteproc.c
+++ b/drivers/remoteproc/omap_remoteproc.c
@@ -130,6 +130,12 @@ static void omap_rproc_mbox_callback(struct mbox_client *client, void *data)
 		dev_info(dev, "received echo reply from %s\n", name);
 		break;
 	default:
+		if (msg >= RP_MBOX_READY && msg < RP_MBOX_END_MSG)
+			return;
+		if (msg > oproc->rproc->max_notifyid) {
+			dev_dbg(dev, "dropping unknown message 0x%x", msg);
+			return;
+		}
 		/* msg contains the index of the triggered vring */
 		if (rproc_vq_interrupt(oproc->rproc, msg) == IRQ_NONE)
 			dev_dbg(dev, "no message was found in vqid %d\n", msg);
diff --git a/drivers/remoteproc/omap_remoteproc.h b/drivers/remoteproc/omap_remoteproc.h
index f6d2036d383d..72f656c93caa 100644
--- a/drivers/remoteproc/omap_remoteproc.h
+++ b/drivers/remoteproc/omap_remoteproc.h
@@ -56,6 +56,12 @@
  *
  * @RP_MBOX_ABORT_REQUEST: a "please crash" request, used for testing the
  * recovery mechanism (to some extent).
+ *
+ * Introduce new message definitions if any here.
+ *
+ * @RP_MBOX_END_MSG: Indicates end of known/defined messages from remote core
+ * This should be the last definition.
+ *
  */
 enum omap_rp_mbox_messages {
 	RP_MBOX_READY		= 0xFFFFFF00,
@@ -64,6 +70,7 @@ enum omap_rp_mbox_messages {
 	RP_MBOX_ECHO_REQUEST	= 0xFFFFFF03,
 	RP_MBOX_ECHO_REPLY	= 0xFFFFFF04,
 	RP_MBOX_ABORT_REQUEST	= 0xFFFFFF05,
+	RP_MBOX_END_MSG		= 0xFFFFFF06,
 };
 
 #endif /* _OMAP_RPMSG_H */
-- 
2.17.1

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