On 2019-10-17 16:53:58 [+0200], Daniel Borkmann wrote: > On Thu, Oct 17, 2019 at 11:05:01AM +0200, Sebastian Andrzej Siewior wrote: > > Disable BPF on PREEMPT_RT because > > - it allocates and frees memory in atomic context > > - it uses up_read_non_owner() > > - BPF_PROG_RUN() expects to be invoked in non-preemptible context > > For the latter you'd also need to disable seccomp-BPF and everything > cBPF related as they are /all/ invoked via BPF_PROG_RUN() ... I looked at tracing and it depended on BPF_SYSCALL so I assumed they all do… Now looking for BPF_PROG_RUN() there is PPP_FILTER, NET_TEAM_MODE_LOADBALANCE and probably more. I didn't find a symbol for seccomp-BPF. Would it make sense to override BPF_PROG_RUN() and make each caller fail instead? Other recommendations? Sebastian
