From: Yonghong Song <yonghong.song@linux.dev>
To: Anton Protopopov <a.s.protopopov@gmail.com>,
bpf@vger.kernel.org, Alexei Starovoitov <ast@kernel.org>,
Andrii Nakryiko <andrii@kernel.org>,
Anton Protopopov <aspsk@isovalent.com>,
Daniel Borkmann <daniel@iogearbox.net>,
Eduard Zingerman <eddyz87@gmail.com>,
Quentin Monnet <qmo@kernel.org>
Subject: Re: [PATCH v5 bpf-next 13/15] libbpf: support llvm-generated indirect jumps
Date: Wed, 15 Oct 2025 08:32:32 -0700 [thread overview]
Message-ID: <4a536cda-0ba5-437f-82ae-60468a75a62c@linux.dev> (raw)
In-Reply-To: <20250930125111.1269861-14-a.s.protopopov@gmail.com>
On 9/30/25 5:51 AM, Anton Protopopov wrote:
> For v5 instruction set LLVM is allowed to generate indirect jumps for
FYI. The llvm jump table support is still cpu v4.
> switch statements and for 'goto *rX' assembly. Every such a jump will
> be accompanied by necessary metadata, e.g. (`llvm-objdump -Sr ...`):
>
> 0: r2 = 0x0 ll
> 0000000000000030: R_BPF_64_64 BPF.JT.0.0
>
> Here BPF.JT.1.0 is a symbol residing in the .jumptables section:
>
> Symbol table:
> 4: 0000000000000000 240 OBJECT GLOBAL DEFAULT 4 BPF.JT.0.0
>
> The -bpf-min-jump-table-entries llvm option may be used to control the
> minimal size of a switch which will be converted to an indirect jumps.
>
> Signed-off-by: Anton Protopopov <a.s.protopopov@gmail.com>
[...]
next prev parent reply other threads:[~2025-10-15 15:32 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-09-30 12:50 [PATCH v5 bpf-next 00/15] BPF indirect jumps Anton Protopopov
2025-09-30 12:50 ` [PATCH v5 bpf-next 01/15] bpf: fix the return value of push_stack Anton Protopopov
2025-09-30 12:50 ` [PATCH v5 bpf-next 02/15] bpf: save the start of functions in bpf_prog_aux Anton Protopopov
2025-10-01 21:53 ` Eduard Zingerman
2025-09-30 12:50 ` [PATCH v5 bpf-next 03/15] bpf: generalize and export map_get_next_key for arrays Anton Protopopov
2025-10-01 21:56 ` Eduard Zingerman
2025-09-30 12:51 ` [PATCH v5 bpf-next 04/15] bpf, x86: add new map type: instructions array Anton Protopopov
2025-10-03 0:50 ` Eduard Zingerman
2025-10-03 7:39 ` Anton Protopopov
2025-10-03 8:48 ` Eduard Zingerman
2025-10-03 9:13 ` Anton Protopopov
2025-10-03 17:22 ` Eduard Zingerman
2025-09-30 12:51 ` [PATCH v5 bpf-next 05/15] selftests/bpf: add selftests for new insn_array map Anton Protopopov
2025-10-03 1:16 ` Eduard Zingerman
2025-10-03 7:46 ` Anton Protopopov
2025-10-03 8:15 ` Eduard Zingerman
2025-09-30 12:51 ` [PATCH v5 bpf-next 06/15] bpf: support instructions arrays with constants blinding Anton Protopopov
2025-10-03 17:38 ` Eduard Zingerman
2025-09-30 12:51 ` [PATCH v5 bpf-next 07/15] selftests/bpf: test instructions arrays with blinding Anton Protopopov
2025-10-03 9:00 ` Eduard Zingerman
2025-09-30 12:51 ` [PATCH v5 bpf-next 08/15] bpf, x86: allow indirect jumps to r8...r15 Anton Protopopov
2025-10-01 22:03 ` Eduard Zingerman
2025-09-30 12:51 ` [PATCH v5 bpf-next 09/15] bpf: make bpf_insn_successors to return a pointer Anton Protopopov
2025-10-01 22:39 ` Eduard Zingerman
2025-10-01 23:49 ` Alexei Starovoitov
2025-10-02 8:19 ` Anton Protopopov
2025-10-02 16:07 ` Alexei Starovoitov
2025-10-02 8:16 ` Anton Protopopov
2025-10-02 19:35 ` Eduard Zingerman
2025-09-30 12:51 ` [PATCH v5 bpf-next 10/15] bpf, x86: add support for indirect jumps Anton Protopopov
2025-10-02 0:15 ` Eduard Zingerman
2025-10-02 9:27 ` Anton Protopopov
2025-10-02 19:52 ` Eduard Zingerman
2025-10-03 7:04 ` Anton Protopopov
2025-09-30 12:51 ` [PATCH v5 bpf-next 11/15] bpf: disasm: add support for BPF_JMP|BPF_JA|BPF_X Anton Protopopov
2025-10-02 0:18 ` Eduard Zingerman
2025-10-02 7:49 ` Anton Protopopov
2025-09-30 12:51 ` [PATCH v5 bpf-next 12/15] libbpf: fix formatting of bpf_object__append_subprog_code Anton Protopopov
2025-09-30 12:51 ` [PATCH v5 bpf-next 13/15] libbpf: support llvm-generated indirect jumps Anton Protopopov
2025-10-02 21:01 ` Eduard Zingerman
2025-10-03 7:19 ` Anton Protopopov
2025-10-15 15:32 ` Yonghong Song [this message]
2025-10-15 17:35 ` Anton Protopopov
2025-09-30 12:51 ` [PATCH v5 bpf-next 14/15] bpftool: Recognize insn_array map type Anton Protopopov
2025-09-30 12:51 ` [PATCH v5 bpf-next 15/15] selftests/bpf: add selftests for indirect jumps Anton Protopopov
2025-10-02 21:07 ` Eduard Zingerman
2025-10-03 7:22 ` Anton Protopopov
2025-10-03 7:29 ` Eduard Zingerman
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