Commit 9c400d35 authored by Andrea Parri (Microsoft)'s avatar Andrea Parri (Microsoft) Committed by Wei Liu
Browse files

Drivers: hv: vmbus: Reduce number of references to message in vmbus_on_msg_dpc() 



Simplify the function by removing various references to the hv_message
'msg', introduce local variables 'msgtype' and 'payload_size'.

Suggested-by: default avatarJuan Vazquez <juvazq@microsoft.com>
Suggested-by: default avatarMichael Kelley <mikelley@microsoft.com>
Signed-off-by: default avatarAndrea Parri (Microsoft) <parri.andrea@gmail.com>
Reviewed-by: default avatarMichael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20201209070827.29335-3-parri.andrea@gmail.com


Signed-off-by: default avatarWei Liu <wei.liu@kernel.org>
parent e99c4afb

drivers/hv/vmbus_drv.c

+14 −14
Original line number Diff line number Diff line
@@ -1057,9 +1057,11 @@ void vmbus_on_msg_dpc(unsigned long data) 
	struct hv_message *msg = (struct hv_message *)page_addr +

				  VMBUS_MESSAGE_SINT;

	struct vmbus_channel_message_header *hdr;

	enum vmbus_channel_message_type msgtype;

	const struct vmbus_channel_message_table_entry *entry;

	struct onmessage_work_context *ctx;

	u32 message_type = msg->header.message_type;

	__u8 payload_size;



	/*

	 * 'enum vmbus_channel_message_type' is supposed to always be 'u32' as
@@ -1073,40 +1075,38 @@ void vmbus_on_msg_dpc(unsigned long data) 
		return;



	hdr = (struct vmbus_channel_message_header *)msg->u.payload;

	msgtype = hdr->msgtype;



	trace_vmbus_on_msg_dpc(hdr);



	if (hdr->msgtype >= CHANNELMSG_COUNT) {

		WARN_ONCE(1, "unknown msgtype=%d\n", hdr->msgtype);

	if (msgtype >= CHANNELMSG_COUNT) {

		WARN_ONCE(1, "unknown msgtype=%d\n", msgtype);

		goto msg_handled;

	}



	if (msg->header.payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT) {

		WARN_ONCE(1, "payload size is too large (%d)\n",

			  msg->header.payload_size);

	payload_size = msg->header.payload_size;

	if (payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT) {

		WARN_ONCE(1, "payload size is too large (%d)\n", payload_size);

		goto msg_handled;

	}



	entry = &channel_message_table[hdr->msgtype];

	entry = &channel_message_table[msgtype];



	if (!entry->message_handler)

		goto msg_handled;



	if (msg->header.payload_size < entry->min_payload_len) {

		WARN_ONCE(1, "message too short: msgtype=%d len=%d\n",

			  hdr->msgtype, msg->header.payload_size);

	if (payload_size < entry->min_payload_len) {

		WARN_ONCE(1, "message too short: msgtype=%d len=%d\n", msgtype, payload_size);

		goto msg_handled;

	}



	if (entry->handler_type	== VMHT_BLOCKING) {

		ctx = kmalloc(sizeof(*ctx) + msg->header.payload_size,

			      GFP_ATOMIC);

		ctx = kmalloc(sizeof(*ctx) + payload_size, GFP_ATOMIC);

		if (ctx == NULL)

			return;



		INIT_WORK(&ctx->work, vmbus_onmessage_work);

		memcpy(&ctx->msg, msg, sizeof(msg->header) +

		       msg->header.payload_size);

		memcpy(&ctx->msg, msg, sizeof(msg->header) + payload_size);



		/*

		 * The host can generate a rescind message while we
@@ -1115,7 +1115,7 @@ void vmbus_on_msg_dpc(unsigned long data) 
		 * by offer_in_progress and by channel_mutex.  See also the

		 * inline comments in vmbus_onoffer_rescind().

		 */

		switch (hdr->msgtype) {

		switch (msgtype) {

		case CHANNELMSG_RESCIND_CHANNELOFFER:

			/*

			 * If we are handling the rescind message;