On Mon, Jan 28, 2019 at 01:37:12PM -0800, Alexei Starovoitov wrote: > On Mon, Jan 28, 2019 at 09:43:10AM +0100, Peter Zijlstra wrote:
> > Isn't that still broken? AFAIU networking progs can happen in task > > context (TX) and SoftIRQ context (RX), which can nest. > > Sure. sendmsg side of networking can be interrupted by napi receive. > Both can have bpf progs attached at different points, but napi won't run > when bpf prog is running, because bpf prog disables preemption. Disabling preemption is not sufficient, it needs to have done local_bh_disable(), which isn't unlikely given this is all networking code. Anyway, if you're sure that's all good, I'll trust you on that. It's been a very _very_ long time since I looked at the networking code.
