Saeed Mahameed <sae...@mellanox.com> writes: > On Wed, 2018-10-03 at 11:30 +0200, Toke Høiland-Jørgensen wrote: >> Hi Saeed >> >> I can reliably oops the kernel with the mlx5 driver, by installing >> XDP_REDIRECT programs on two devices so they redirect to each other, >> and then remove them while there is traffic on the interface. >> >> Steps to reproduce: >> >> # cd ~/build/linux/samples/bpf >> # ./xdp_redirect_map $(</sys/class/net/ens1f1/ifindex) >> $(</sys/class/net/ens1f0/ifindex) >> # ./xdp_redirect_map $(</sys/class/net/ens1f0/ifindex) >> $(</sys/class/net/ens1f1/ifindex) >> >> Now, run some traffic (e.g., using pktgen) across the interfaces, and >> while the traffic is running, interrupt one of the xdp_redirect_map >> commands (thus unloading the eBPF program). This results in a kernel >> oops with the backtrace below. I get no crash if there's only a >> single >> XDP program. > > Hi Toke, > > What looks like happening is that while the traffic is being redirected > to the other device, the driver is trying to unload the program and > restarting the rings from below call trace we can see:
Yeah, thought it was something like that, since it only happens on the bidirectional redirect... > I think that the mlx5 driver doesn't know how to tell the other device > to stop transmitting to it while it is resetting.. Maybe tariq or > Jesper know more about this ? > I will look at this tomorrow after noon and will try to repro... Great, thanks! :) -Toke
