From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BF59EC77B7F for ; Thu, 11 May 2023 14:22:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238436AbjEKOWi (ORCPT ); Thu, 11 May 2023 10:22:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40842 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238421AbjEKOW2 (ORCPT ); Thu, 11 May 2023 10:22:28 -0400 Received: from dggsgout11.his.huawei.com (unknown [45.249.212.51]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 156E6106E6; Thu, 11 May 2023 07:22:15 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.30.67.153]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4QHDcK4bL0z4f3l8W; Thu, 11 May 2023 22:22:09 +0800 (CST) Received: from [10.67.111.192] (unknown [10.67.111.192]) by APP4 (Coremail) with SMTP id gCh0CgCneK8R+lxkCyLsJA--.46604S2; Thu, 11 May 2023 22:22:10 +0800 (CST) Message-ID: <7d5cc151-e6c3-73a9-59c0-c4e5821cec1c@huaweicloud.com> Date: Thu, 11 May 2023 22:22:09 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.9.0 Subject: Re: [PATCH bpf-next v2] arm64,bpf: Support struct arguments in the BPF trampoline Content-Language: en-US To: Florent Revest , bpf@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, kpsingh@kernel.org, mark.rutland@arm.com, zlim.lnx@gmail.com, yhs@meta.com, Yonghong Song References: <20230511140507.514888-1-revest@chromium.org> From: Xu Kuohai In-Reply-To: <20230511140507.514888-1-revest@chromium.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-CM-TRANSID: gCh0CgCneK8R+lxkCyLsJA--.46604S2 X-Coremail-Antispam: 1UD129KBjvdXoW7Jr13uFWxWr17CF1rWr4kJFb_yoW3WFbE9F ZrtF97G398t3W3tr129r43Zr93CFW7GF13KF4ftryIv34kZrWDCa4vk3sxtw48tFW2qFnx A3Z8tryIqrW3WjkaLaAFLSUrUUUUUb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUbIxYFVCjjxCrM7AC8VAFwI0_Gr0_Xr1l1xkIjI8I6I8E6xAIw20E Y4v20xvaj40_Wr0E3s1l1IIY67AEw4v_Jr0_Jr4l8cAvFVAK0II2c7xJM28CjxkF64kEwV A0rcxSw2x7M28EF7xvwVC0I7IYx2IY67AKxVW7JVWDJwA2z4x0Y4vE2Ix0cI8IcVCY1x02 67AKxVW8Jr0_Cr1UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I 0E14v26rxl6s0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40E x7xfMcIj6xIIjxv20xvE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x 0Yz7v_Jr0_Gr1lF7xvr2IY64vIr41lFIxGxcIEc7CjxVA2Y2ka0xkIwI1lc7I2V7IY0VAS 07AlzVAYIcxG8wCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c 02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_Jw0_ GFylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7 CjxVAFwI0_Gr0_Cr1lIxAIcVCF04k26cxKx2IYs7xG6rW3Jr0E3s1lIxAIcVC2z280aVAF wI0_Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa 7IU1zuWJUUUUU== X-CM-SenderInfo: 50xn30hkdlqx5xdzvxpfor3voofrz/ X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 5/11/2023 10:05 PM, Florent Revest wrote: > This extends the BPF trampoline JIT to support attachment to functions > that take small structures (up to 128bit) as argument. This is trivially > achieved by saving/restoring a number of "argument registers" rather > than a number of arguments. > > The AAPCS64 section 6.8.2 describes the parameter passing ABI. > "Composite types" (like C structs) below 16 bytes (as enforced by the > BPF verifier) are provided as part of the 8 argument registers as > explained in the section C.12. > > Signed-off-by: Florent Revest > Acked-by: Yonghong Song > --- > > Diff since v1: The stack layout comment now says "arg reg" instead of "arg". > LGTM. Thanks for updating the description.