On Tue, Nov 21, 2017 at 2:31 PM, Alexei Starovoitov
<alexei.starovoi...@gmail.com> wrote:
>
> yeah sorry about this hack. Gianluca reported this issue as well.
> Yonghong fixed it for bpf_probe_read only. We will extend
> the fix to bpf_probe_read_str() and bpf_perf_event_output() asap.
> The above workaround gets too much into llvm and verifier details
> we should strive to make bpf program writing as easy as possible.
>
Hi Arnaldo
With the help of Alexei, Daniel and Yonghong I just submitted a new
series ("bpf: fix semantics issues with helpers receiving NULL
arguments") that includes a fix in bpf_perf_event_output. This should
simplify the way you write your bpf programs, so you shouldn't be
required to write those convoluted branches anymore (there are a few
usage examples in the commit log).
In my case it made writing the code much easier, after applying it I
haven't been surprised by the compiler output in a while, and I hope
your experience will be improved as well.
Thanks
