From: Eduard Zingerman <eddyz87@gmail.com>
To: Yonghong Song <yonghong.song@linux.dev>, bpf@vger.kernel.org
Cc: Alexei Starovoitov <ast@kernel.org>,
Andrii Nakryiko <andrii@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
"Jose E . Marchesi" <jose.marchesi@oracle.com>,
kernel-team@fb.com, Martin KaFai Lau <martin.lau@kernel.org>
Subject: Re: [PATCH bpf-next 07/18] bpf: Enable r11 based insns
Date: Wed, 29 Apr 2026 05:48:04 -0700 [thread overview]
Message-ID: <006c46ba8ea2a37d0fa75f82645e2c011c72cc8a.camel@gmail.com> (raw)
In-Reply-To: <20260424171509.2041667-1-yonghong.song@linux.dev>
On Fri, 2026-04-24 at 10:15 -0700, Yonghong Song wrote:
> BPF_REG_PARAMS (r11) is used for stack argument accesses and
> the following are the only insns with r11 presence:
> - BPF_LDX | BPF_MEM | BPF_DW (load incoming stack arg)
> - BPF_STX | BPF_MEM | BPF_DW (store register to outgoing stack arg)
> - BPF_ST | BPF_MEM | BPF_DW (store immediate to outgoing stack arg)
>
> Additionally, validate offsets: loads must use positive 8-byte aligned
> offsets (8, 16, ...) since they access incoming args. Stores must use
> negative 8-byte aligned offsets (-8, -16, ...) since they write
> outgoing args.
>
> The LLVM compiler [1] implemented the above BPF_REG_PARAMS insns.
>
> [1] https://github.com/llvm/llvm-project/pull/189060
>
> Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
> ---
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Nit: the is_stack_arg_{st,stx,ldx} accessors I talked about earlier
would have been useful here.
[...]
next prev parent reply other threads:[~2026-04-29 12:48 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-04-24 17:14 [PATCH bpf-next 00/18] bpf: Support stack arguments for BPF functions and kfuncs Yonghong Song
2026-04-24 17:14 ` [PATCH bpf-next 01/18] bpf: Support stack arguments for bpf functions Yonghong Song
2026-04-24 18:13 ` bot+bpf-ci
2026-04-25 5:09 ` Yonghong Song
2026-04-27 20:40 ` Yonghong Song
2026-04-28 14:29 ` Eduard Zingerman
2026-04-28 16:47 ` Yonghong Song
2026-04-28 23:50 ` Yonghong Song
2026-04-29 0:28 ` Eduard Zingerman
2026-04-24 17:14 ` [PATCH bpf-next 02/18] bpf: Add precision marking and backtracking for stack argument slots Yonghong Song
2026-04-24 18:00 ` bot+bpf-ci
2026-04-25 5:10 ` Yonghong Song
2026-04-28 16:46 ` Eduard Zingerman
2026-04-28 20:54 ` Yonghong Song
2026-04-24 17:14 ` [PATCH bpf-next 03/18] bpf: Refactor record_call_access() to extract per-arg logic Yonghong Song
2026-04-29 0:51 ` Eduard Zingerman
2026-04-24 17:14 ` [PATCH bpf-next 04/18] bpf: Extend liveness analysis to track stack argument slots Yonghong Song
2026-04-24 18:00 ` bot+bpf-ci
2026-04-25 5:11 ` Yonghong Song
2026-04-29 12:22 ` Eduard Zingerman
2026-04-24 17:14 ` [PATCH bpf-next 05/18] bpf: Reject stack arguments in non-JITed programs Yonghong Song
2026-04-24 18:00 ` bot+bpf-ci
2026-04-29 12:27 ` Eduard Zingerman
2026-04-24 17:15 ` [PATCH bpf-next 06/18] bpf: Prepare architecture JIT support for stack arguments Yonghong Song
2026-04-24 17:48 ` bot+bpf-ci
2026-04-25 5:17 ` Yonghong Song
2026-04-29 12:37 ` Eduard Zingerman
2026-04-24 17:15 ` [PATCH bpf-next 07/18] bpf: Enable r11 based insns Yonghong Song
2026-04-29 12:48 ` Eduard Zingerman [this message]
2026-04-24 17:15 ` [PATCH bpf-next 08/18] bpf: Support stack arguments for kfunc calls Yonghong Song
2026-04-24 18:00 ` bot+bpf-ci
2026-04-25 5:19 ` Yonghong Song
2026-04-24 17:15 ` [PATCH bpf-next 09/18] bpf: Reject stack arguments if tail call reachable Yonghong Song
2026-04-24 18:00 ` bot+bpf-ci
2026-04-24 17:15 ` [PATCH bpf-next 10/18] bpf,x86: Implement JIT support for stack arguments Yonghong Song
2026-04-24 18:00 ` bot+bpf-ci
2026-04-25 5:29 ` Yonghong Song
2026-04-24 17:16 ` [PATCH bpf-next 11/18] selftests/bpf: Add tests for BPF function " Yonghong Song
2026-04-24 17:16 ` [PATCH bpf-next 12/18] selftests/bpf: Add tests for stack argument validation Yonghong Song
2026-04-24 17:17 ` [PATCH bpf-next 13/18] selftests/bpf: Add verifier " Yonghong Song
2026-04-24 17:48 ` bot+bpf-ci
2026-04-25 5:33 ` Yonghong Song
2026-04-24 17:17 ` [PATCH bpf-next 14/18] selftests/bpf: Add BTF fixup for __naked subprog parameter names Yonghong Song
2026-04-24 17:17 ` [PATCH bpf-next 15/18] selftests/bpf: Add precision backtracking test for stack arguments Yonghong Song
2026-04-24 17:17 ` [PATCH bpf-next 16/18] bpf, arm64: Map BPF_REG_0 to x8 instead of x7 Yonghong Song
2026-04-24 17:17 ` [PATCH bpf-next 17/18] bpf, arm64: Add JIT support for stack arguments Yonghong Song
2026-04-24 18:00 ` bot+bpf-ci
2026-04-27 9:06 ` Puranjay Mohan
2026-04-27 20:42 ` Yonghong Song
2026-04-24 17:17 ` [PATCH bpf-next 18/18] selftests/bpf: Enable stack argument tests for arm64 Yonghong Song
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