From: K. Y. Srinivasan Date: Wed, 7 Dec 2016 09:16:28 +0000 (-0800) Subject: Drivers: hv: vmbus: Prevent sending data on a rescinded channel X-Git-Tag: v4.11-rc1~118^2~144 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=e7e97dd8b77ee7366f2f8c70a033bf5fa05ec2e0;p=karo-tx-linux.git Drivers: hv: vmbus: Prevent sending data on a rescinded channel After the channel is rescinded, the host does not read from the rescinded channel. Fail writes to a channel that has already been rescinded. If we permit writes on a rescinded channel, since the host will not respond we will have situations where we will be unable to unload vmbus drivers that cannot have any outstanding requests to the host at the point they are unoaded. Signed-off-by: K. Y. Srinivasan Cc: Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c index cd49cb17eb7f..2cd402986858 100644 --- a/drivers/hv/ring_buffer.c +++ b/drivers/hv/ring_buffer.c @@ -298,6 +298,9 @@ int hv_ringbuffer_write(struct vmbus_channel *channel, unsigned long flags = 0; struct hv_ring_buffer_info *outring_info = &channel->outbound; + if (channel->rescind) + return -ENODEV; + for (i = 0; i < kv_count; i++) totalbytes_towrite += kv_list[i].iov_len; @@ -350,6 +353,10 @@ int hv_ringbuffer_write(struct vmbus_channel *channel, spin_unlock_irqrestore(&outring_info->ring_lock, flags); hv_signal_on_write(old_write, channel, kick_q); + + if (channel->rescind) + return -ENODEV; + return 0; }