From: Eduard Zingerman <eddyz87@gmail.com>
To: Anton Protopopov <a.s.protopopov@gmail.com>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>,
bpf <bpf@vger.kernel.org>, Alexei Starovoitov <ast@kernel.org>,
Andrii Nakryiko <andrii@kernel.org>,
Anton Protopopov <aspsk@isovalent.com>,
Daniel Borkmann <daniel@iogearbox.net>,
Quentin Monnet <qmo@kernel.org>,
Yonghong Song <yonghong.song@linux.dev>
Subject: Re: [RFC bpf-next 8/9] libbpf: support llvm-generated indirect jumps
Date: Tue, 08 Jul 2025 22:58:35 -0700 [thread overview]
Message-ID: <f90ea7ec00265ab842e373a69f0ffdbb374f7614.camel@gmail.com> (raw)
In-Reply-To: <aG3/MWCOwdk5z0mp@mail.gmail.com>
On Wed, 2025-07-09 at 05:33 +0000, Anton Protopopov wrote:
[...]
> I think that this is exactly what I had proposed originally in [1],
> so yes, IMO this looks more elegant indeed. (Back then the feedback was
> that this is too esoteric, and instead the verifier should be taught
> to eat what LLVM generates (<<3 and load).) The instruction can be
> extended (SRC and OFF are unused) to support more formats later.
Well, we did a full circle. At-least everybody is on the same page now :)
>
> > 3: gotox r1
> > 0000000000000038: R_BPF_64_64 .BPF.JT.0.0
>
> How hard is to teach the LLVM to generate this?
>
> [1] https://lpc.events/event/18/contributions/1941/
This seems to work:
https://github.com/eddyz87/llvm-project/tree/separate-jumptables-section.1
Needs some tests and probably can be simplified a bit.
next prev parent reply other threads:[~2025-07-09 5:58 UTC|newest]
Thread overview: 63+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-06-15 8:59 [RFC bpf-next 0/9] BPF indirect jumps Anton Protopopov
2025-06-15 8:59 ` [RFC bpf-next 1/9] bpf: save the start of functions in bpf_prog_aux Anton Protopopov
2025-06-15 8:59 ` [RFC bpf-next 2/9] bpf, x86: add new map type: instructions set Anton Protopopov
2025-06-18 0:57 ` Eduard Zingerman
2025-06-18 2:16 ` Alexei Starovoitov
2025-06-19 18:57 ` Anton Protopopov
2025-06-19 18:55 ` Anton Protopopov
2025-06-19 18:55 ` Eduard Zingerman
2025-06-15 8:59 ` [RFC bpf-next 3/9] selftests/bpf: add selftests for new insn_set map Anton Protopopov
2025-06-18 11:04 ` Eduard Zingerman
2025-06-18 15:16 ` Anton Protopopov
2025-06-15 8:59 ` [RFC bpf-next 4/9] bpf, x86: allow indirect jumps to r8...r15 Anton Protopopov
2025-06-17 19:41 ` Alexei Starovoitov
2025-06-18 14:28 ` Anton Protopopov
2025-06-15 8:59 ` [RFC bpf-next 5/9] bpf, x86: add support for indirect jumps Anton Protopopov
2025-06-18 3:06 ` Alexei Starovoitov
2025-06-19 19:57 ` Anton Protopopov
2025-06-19 19:58 ` Anton Protopopov
2025-06-18 11:03 ` Eduard Zingerman
2025-06-19 20:13 ` Anton Protopopov
2025-06-15 8:59 ` [RFC bpf-next 6/9] bpf: workaround llvm behaviour with " Anton Protopopov
2025-06-18 11:04 ` Eduard Zingerman
2025-06-18 13:59 ` Alexei Starovoitov
2025-06-15 8:59 ` [RFC bpf-next 7/9] bpf: disasm: add support for BPF_JMP|BPF_JA|BPF_X Anton Protopopov
2025-06-15 8:59 ` [RFC bpf-next 8/9] libbpf: support llvm-generated indirect jumps Anton Protopopov
2025-06-18 3:22 ` Alexei Starovoitov
2025-06-18 15:08 ` Anton Protopopov
2025-07-07 23:45 ` Eduard Zingerman
2025-07-07 23:49 ` Alexei Starovoitov
2025-07-08 0:01 ` Eduard Zingerman
2025-07-08 0:12 ` Alexei Starovoitov
2025-07-08 0:18 ` Eduard Zingerman
2025-07-08 0:49 ` Alexei Starovoitov
2025-07-08 0:51 ` Eduard Zingerman
2025-07-08 20:59 ` Eduard Zingerman
2025-07-08 21:25 ` Alexei Starovoitov
2025-07-08 21:29 ` Eduard Zingerman
2025-07-09 5:33 ` Anton Protopopov
2025-07-09 5:58 ` Eduard Zingerman [this message]
2025-07-09 8:38 ` Eduard Zingerman
2025-07-10 5:11 ` Eduard Zingerman
2025-07-10 6:10 ` Anton Protopopov
2025-07-10 6:13 ` Eduard Zingerman
2025-06-18 19:49 ` Eduard Zingerman
2025-06-27 2:28 ` Eduard Zingerman
2025-06-27 10:18 ` Anton Protopopov
2025-07-03 18:21 ` Eduard Zingerman
2025-07-03 19:03 ` Anton Protopopov
2025-07-07 19:07 ` Eduard Zingerman
2025-07-07 19:34 ` Anton Protopopov
2025-07-07 21:44 ` Yonghong Song
2025-07-08 5:58 ` Yonghong Song
2025-07-08 8:30 ` Eduard Zingerman
2025-07-08 10:42 ` Eduard Zingerman
2025-06-15 8:59 ` [RFC bpf-next 9/9] selftests/bpf: add selftests for " Anton Protopopov
2025-06-18 3:24 ` Alexei Starovoitov
2025-06-18 14:49 ` Anton Protopopov
2025-06-18 16:01 ` Alexei Starovoitov
2025-06-18 16:36 ` Anton Protopopov
2025-06-18 16:43 ` Alexei Starovoitov
2025-06-18 20:25 ` Anton Protopopov
2025-06-18 21:59 ` Alexei Starovoitov
2025-06-19 5:05 ` Anton Protopopov
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