A security fix briefly breaks DMA

Posted Apr 7, 2022 15:16 UTC (Thu) by kpfleming (subscriber, #23250)
In reply to: A security fix briefly breaks DMA by developer122
Parent article: A security fix briefly breaks DMA

I'm not sure that's fair.

You tell a NIC it can receive a packet directly into a buffer. It does so. You don't know how large the packet was until you look into the buffer to find out.

The NIC could conceivably communicate the 'bytes written' amount in some other location outside the buffer, but that significantly complicates the data handling.