From: Dexuan Cui decui@microsoft.com
[ Upstream commit ddc9d357b991838c2d975e8d7e4e9db26f37a7ff ]
When a Linux hv_sock app tries to connect to a Service GUID on which no host app is listening, a recent host (RS3+) sends a CHANNELMSG_TL_CONNECT_RESULT (23) message to Linux and this triggers such a warning:
unknown msgtype=23 WARNING: CPU: 2 PID: 0 at drivers/hv/vmbus_drv.c:1031 vmbus_on_msg_dpc
Actually Linux can safely ignore the message because the Linux app's connect() will time out in 2 seconds: see VSOCK_DEFAULT_CONNECT_TIMEOUT and vsock_stream_connect(). We don't bother to make use of the message because: 1) it's only supported on recent hosts; 2) a non-trivial effort is required to use the message in Linux, but the benefit is small.
So, let's not see the warning by silently ignoring the message.
Signed-off-by: Dexuan Cui decui@microsoft.com Reviewed-by: Michael Kelley mikelley@microsoft.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/hv/channel_mgmt.c | 21 +++++++-------------- drivers/hv/vmbus_drv.c | 4 ++++ include/linux/hyperv.h | 2 ++ 3 files changed, 13 insertions(+), 14 deletions(-)
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c index 43eaf54736f4e..462f7f363faab 100644 --- a/drivers/hv/channel_mgmt.c +++ b/drivers/hv/channel_mgmt.c @@ -1228,6 +1228,8 @@ channel_message_table[CHANNELMSG_COUNT] = { { CHANNELMSG_19, 0, NULL }, { CHANNELMSG_20, 0, NULL }, { CHANNELMSG_TL_CONNECT_REQUEST, 0, NULL }, + { CHANNELMSG_22, 0, NULL }, + { CHANNELMSG_TL_CONNECT_RESULT, 0, NULL }, };
/* @@ -1239,23 +1241,14 @@ void vmbus_onmessage(void *context) { struct hv_message *msg = context; struct vmbus_channel_message_header *hdr; - int size;
hdr = (struct vmbus_channel_message_header *)msg->u.payload; - size = msg->header.payload_size;
- if (hdr->msgtype >= CHANNELMSG_COUNT) { - pr_err("Received invalid channel message type %d size %d\n", - hdr->msgtype, size); - print_hex_dump_bytes("", DUMP_PREFIX_NONE, - (unsigned char *)msg->u.payload, size); - return; - } - - if (channel_message_table[hdr->msgtype].message_handler) - channel_message_table[hdr->msgtype].message_handler(hdr); - else - pr_err("Unhandled channel message type %d\n", hdr->msgtype); + /* + * vmbus_on_msg_dpc() makes sure the hdr->msgtype here can not go + * out of bound and the message_handler pointer can not be NULL. + */ + channel_message_table[hdr->msgtype].message_handler(hdr); }
/* diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c index 1fd812ed679b4..45b8ccdfb0852 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -890,6 +890,10 @@ void vmbus_on_msg_dpc(unsigned long data) }
entry = &channel_message_table[hdr->msgtype]; + + if (!entry->message_handler) + goto msg_handled; + if (entry->handler_type == VMHT_BLOCKING) { ctx = kmalloc(sizeof(*ctx), GFP_ATOMIC); if (ctx == NULL) diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h index 8d3ca6da33421..63cd81e5610d1 100644 --- a/include/linux/hyperv.h +++ b/include/linux/hyperv.h @@ -422,6 +422,8 @@ enum vmbus_channel_message_type { CHANNELMSG_19 = 19, CHANNELMSG_20 = 20, CHANNELMSG_TL_CONNECT_REQUEST = 21, + CHANNELMSG_22 = 22, + CHANNELMSG_TL_CONNECT_RESULT = 23, CHANNELMSG_COUNT };