Re: dumpcap: weird failure with six IPv6 hosts in the filter

[Isaac Boukris <iboukris@gmail.com>]

On Mon, Jun 17, 2024 at 10:37 PM Isaac Boukris <iboukris@gmail.com> wrote:
>
> > Just a quick update that I still see the issue in my env with the
> > master branch (24.07.0-rc0), I'm now testing by adding the filter to
> > 'sample_filters' in test_bpf.c and running:
> > time sudo build/app/dpdk-test bpf_convert_autotest
> >
> > With 5 hosts it takes less than 2 secs, with 6 it takes about 25 secs,
> > i'll try to strace it maybe.
>
> strace was useless, no syscalls for ~18 secs, not sure how to debug it
> further, valgrind / callgrind don't work on dpdk..
>
> It doesn't seem to be about the size though, I was able to produce
> larger bpf code with ipv4 addresses and it worked fine too.

Debugged a bit further with gdb, it looks like it is stuck in a while
loop in lib/bpf/bpf_validate.c:evaluate(), there is a comment saying
"make sure we evaluate each node only once" but it seem to go back and
forth on the same idx's afaict.