ASoC: SOF: Refactor rx function for fuzzing

Refactor the function so reading the data is done outside the work
function so fuzzing can pass data directly into the work callbacks.

Also expose the inner function outside the module so we can call it from
the injector.
Signed-off-by: Curtis Malainey <cujomalainey@chromium.org>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Péter Ujfalusi <peter.ujfalusi@linux.intel.com>
Link: https://lore.kernel.org/r/20230608221822.2825786-1-cujomalainey@chromium.orgSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/sof/ipc3-priv.h

@@ -28,6 +28,8 @@ int sof_ipc3_validate_fw_version(struct snd_sof_dev *sdev);
 /* dtrace position update */
 int ipc3_dtrace_posn_update(struct snd_sof_dev *sdev,
 			    struct sof_ipc_dma_trace_posn *posn);
+/* RX handler backend */
+void sof_ipc3_do_rx_work(struct snd_sof_dev *sdev, struct sof_ipc_cmd_hdr *hdr, void *msg_buf);
 
 /* dtrace platform callback wrappers */
 static inline int sof_dtrace_host_init(struct snd_sof_dev *sdev,

sound/soc/sof/ipc3.c

@@ -954,31 +954,21 @@ static void ipc3_trace_message(struct snd_sof_dev *sdev, void *msg_buf)
 	}
 }
 
-/* DSP firmware has sent host a message  */
-static void sof_ipc3_rx_msg(struct snd_sof_dev *sdev)
+void sof_ipc3_do_rx_work(struct snd_sof_dev *sdev, struct sof_ipc_cmd_hdr *hdr, void *msg_buf)
 {
 	ipc3_rx_callback rx_callback = NULL;
-	struct sof_ipc_cmd_hdr hdr;
-	void *msg_buf;
 	u32 cmd;
 	int err;
 
-	/* read back header */
-	err = snd_sof_ipc_msg_data(sdev, NULL, &hdr, sizeof(hdr));
-	if (err < 0) {
-		dev_warn(sdev->dev, "failed to read IPC header: %d\n", err);
-		return;
-	}
+	ipc3_log_header(sdev->dev, "ipc rx", hdr->cmd);
 
-	if (hdr.size < sizeof(hdr) || hdr.size > SOF_IPC_MSG_MAX_SIZE) {
+	if (hdr->size < sizeof(hdr) || hdr->size > SOF_IPC_MSG_MAX_SIZE) {
 		dev_err(sdev->dev, "The received message size is invalid: %u\n",
-			hdr.size);
+			hdr->size);
 		return;
 	}
 
-	ipc3_log_header(sdev->dev, "ipc rx", hdr.cmd);
-
-	cmd = hdr.cmd & SOF_GLB_TYPE_MASK;
+	cmd = hdr->cmd & SOF_GLB_TYPE_MASK;
 
 	/* check message type */
 	switch (cmd) {
@@ -1016,6 +1006,36 @@ static void sof_ipc3_rx_msg(struct snd_sof_dev *sdev)
 		break;
 	}
 
+	/* Call local handler for the message */
+	if (rx_callback)
+		rx_callback(sdev, msg_buf);
+
+	/* Notify registered clients */
+	sof_client_ipc_rx_dispatcher(sdev, msg_buf);
+
+	ipc3_log_header(sdev->dev, "ipc rx done", hdr->cmd);
+}
+EXPORT_SYMBOL(sof_ipc3_do_rx_work);
+
+/* DSP firmware has sent host a message  */
+static void sof_ipc3_rx_msg(struct snd_sof_dev *sdev)
+{
+	struct sof_ipc_cmd_hdr hdr;
+	void *msg_buf;
+	int err;
+
+	/* read back header */
+	err = snd_sof_ipc_msg_data(sdev, NULL, &hdr, sizeof(hdr));
+	if (err < 0) {
+		dev_warn(sdev->dev, "failed to read IPC header: %d\n", err);
+		return;
+	}
+
+	if (hdr.size < sizeof(hdr)) {
+		dev_err(sdev->dev, "The received message size is invalid\n");
+		return;
+	}
+
 	/* read the full message */
 	msg_buf = kmalloc(hdr.size, GFP_KERNEL);
 	if (!msg_buf)
@@ -1024,18 +1044,13 @@ static void sof_ipc3_rx_msg(struct snd_sof_dev *sdev)
 	err = snd_sof_ipc_msg_data(sdev, NULL, msg_buf, hdr.size);
 	if (err < 0) {
 		dev_err(sdev->dev, "%s: Failed to read message: %d\n", __func__, err);
-	} else {
-		/* Call local handler for the message */
-		if (rx_callback)
-			rx_callback(sdev, msg_buf);
-
-		/* Notify registered clients */
-		sof_client_ipc_rx_dispatcher(sdev, msg_buf);
+		kfree(msg_buf);
+		return;
 	}
 
-	kfree(msg_buf);
+	sof_ipc3_do_rx_work(sdev, &hdr, msg_buf);
 
-	ipc3_log_header(sdev->dev, "ipc rx done", hdr.cmd);
+	kfree(msg_buf);
 }
 
 static int sof_ipc3_set_core_state(struct snd_sof_dev *sdev, int core_idx, bool on)