Commit a276463b authored by Vitaly Kuznetsov's avatar Vitaly Kuznetsov Committed by Wei Liu
Browse files

Drivers: hv: allocate the exact needed memory for messages 



When we need to pass a buffer with Hyper-V message we don't need to always
allocate 256 bytes for the message: the real message length is known from
the header. Change 'struct onmessage_work_context' to make it possible to
not over-allocate.

Signed-off-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: default avatarMichael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20200406104154.45010-3-vkuznets@redhat.com


Signed-off-by: default avatarWei Liu <wei.liu@kernel.org>
parent ac0f7d42

drivers/hv/vmbus_drv.c

+10 −5
Original line number Diff line number Diff line
@@ -1019,7 +1019,10 @@ static struct bus_type hv_bus = { 


struct onmessage_work_context {

	struct work_struct work;

	struct hv_message msg;

	struct {

		struct hv_message_header header;

		u8 payload[];

	} msg;

};



static void vmbus_onmessage_work(struct work_struct *work)
@@ -1072,7 +1075,8 @@ void vmbus_on_msg_dpc(unsigned long data) 
		goto msg_handled;



	if (entry->handler_type	== VMHT_BLOCKING) {

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

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

			      GFP_ATOMIC);

		if (ctx == NULL)

			return;
@@ -1126,10 +1130,11 @@ static void vmbus_force_channel_rescinded(struct vmbus_channel *channel) 
	WARN_ON(!is_hvsock_channel(channel));



	/*

	 * sizeof(*ctx) is small and the allocation should really not fail,

	 * Allocation size is small and the allocation should really not fail,

	 * otherwise the state of the hv_sock connections ends up in limbo.

	 */

	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL | __GFP_NOFAIL);

	ctx = kzalloc(sizeof(*ctx) + sizeof(*rescind),

		      GFP_KERNEL | __GFP_NOFAIL);



	/*

	 * So far, these are not really used by Linux. Just set them to the
@@ -1139,7 +1144,7 @@ static void vmbus_force_channel_rescinded(struct vmbus_channel *channel) 
	ctx->msg.header.payload_size = sizeof(*rescind);



	/* These values are actually used by Linux. */

	rescind = (struct vmbus_channel_rescind_offer *)ctx->msg.u.payload;

	rescind = (struct vmbus_channel_rescind_offer *)ctx->msg.payload;

	rescind->header.msgtype = CHANNELMSG_RESCIND_CHANNELOFFER;

	rescind->child_relid = channel->offermsg.child_relid;