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authorVitaly Kuznetsov <vkuznets@redhat.com>2020-04-06 13:41:51 +0300
committerWei Liu <wei.liu@kernel.org>2020-04-23 16:17:10 +0300
commita276463b7aeb6186e7e4315cccb032773fb31b5d (patch)
tree146a66a72e15b62f8f48a6c71fb8f62ca2c50521 /drivers
parentac0f7d42584125dab8039e60ab4ade48cc2db61c (diff)
downloadlinux-a276463b7aeb6186e7e4315cccb032773fb31b5d.tar.xz
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: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20200406104154.45010-3-vkuznets@redhat.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/hv/vmbus_drv.c15
1 files changed, 10 insertions, 5 deletions
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 183a5b07c3ad..e356ea4752c0 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -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;