From: Eduard Zingerman <eddyz87@gmail.com>
To: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Nick Zavaritsky <mejedi@gmail.com>, bpf <bpf@vger.kernel.org>,
Alexei Starovoitov <ast@kernel.org>,
Andrii Nakryiko <andrii@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Martin KaFai Lau <martin.lau@linux.dev>,
Kernel Team <kernel-team@fb.com>,
Yonghong Song <yonghong.song@linux.dev>
Subject: Re: [PATCH bpf v2 7/8] bpf: consider that tail calls invalidate packet pointers
Date: Tue, 10 Dec 2024 10:52:30 -0800 [thread overview]
Message-ID: <7bc3b90bc810df379f9463ebc62210c3819725bd.camel@gmail.com> (raw)
In-Reply-To: <CAADnVQ+hsXZirUYJ6Dshn+K6XNJB7LC=cS5ZzHXiMQbot+SJ3w@mail.gmail.com>
On Tue, 2024-12-10 at 10:31 -0800, Alexei Starovoitov wrote:
[...]
> > > > From an end-user perspective, the presented solution makes debugging
> > > > verifier errors harder. An error message doesn't tell which call
> > > > invalidated pointers. Whether verifier considers a particular sub
> > > > program as pointer-invalidating is not revealed. I foresee exciting
> > > > debugging sessions.
> > >
> > > There is such a risk.
> >
> > I can do a v4 and add a line in the log each time the packet pointers
> > are invalidated. Such lines would be presented in verification failure
> > logs. (Can also print every register/stack slot where packet pointer
> > is invalidated, but this may be too verbose).
>
> This is something to consider for bpf-next.
> For bpf we need a minimal fix. So I applied as-is.
I must admit, I'm not familiar with the way bpf/bpf-next interact.
Should I wait for certain merges to happen before posting a patch
to bpf-next?
next prev parent reply other threads:[~2024-12-10 18:52 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-12-10 4:10 [PATCH bpf v2 0/8] bpf: track changes_pkt_data property for global functions Eduard Zingerman
2024-12-10 4:10 ` [PATCH bpf v2 1/8] bpf: add find_containing_subprog() utility function Eduard Zingerman
2024-12-10 4:10 ` [PATCH bpf v2 2/8] bpf: refactor bpf_helper_changes_pkt_data to use helper number Eduard Zingerman
2024-12-10 4:10 ` [PATCH bpf v2 3/8] bpf: track changes_pkt_data property for global functions Eduard Zingerman
2024-12-10 4:10 ` [PATCH bpf v2 4/8] selftests/bpf: test for changing packet data from " Eduard Zingerman
2024-12-10 4:10 ` [PATCH bpf v2 5/8] bpf: check changes_pkt_data property for extension programs Eduard Zingerman
2024-12-10 4:10 ` [PATCH bpf v2 6/8] selftests/bpf: freplace tests for tracking of changes_packet_data Eduard Zingerman
2024-12-10 4:10 ` [PATCH bpf v2 7/8] bpf: consider that tail calls invalidate packet pointers Eduard Zingerman
2024-12-10 10:35 ` Nick Zavaritsky
2024-12-10 18:23 ` Alexei Starovoitov
2024-12-10 18:29 ` Eduard Zingerman
2024-12-10 18:31 ` Alexei Starovoitov
2024-12-10 18:52 ` Eduard Zingerman [this message]
2024-12-10 19:00 ` Alexei Starovoitov
2024-12-10 19:06 ` Eduard Zingerman
2024-12-10 4:11 ` [PATCH bpf v2 8/8] selftests/bpf: validate that tail call invalidates " Eduard Zingerman
2024-12-10 18:40 ` [PATCH bpf v2 0/8] bpf: track changes_pkt_data property for global functions patchwork-bot+netdevbpf
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