On 10/25/22 04:07, Peter Zijlstra wrote: > I think the focus should be on finding the source sites, not protecting > the target sites. Where can an attacker control the register content and > have an indirect jump/call. How would this work with something like 'struct file_operations' which provide a rich set of indirect calls that frequently have fully user-controlled values in registers? It certainly wouldn't *hurt* to be zeroing out the registers that are unused at indirect call sites. But, the majority of gadgets in this case used rdi and rsi, which are the least likely to be able to be zapped at call sites.