From patchwork Mon Apr 17 08:07:48 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Feng Zhou X-Patchwork-Id: 675463 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 164D4C77B72 for ; Mon, 17 Apr 2023 08:08:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230330AbjDQIIg (ORCPT ); Mon, 17 Apr 2023 04:08:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53604 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230491AbjDQIIf (ORCPT ); Mon, 17 Apr 2023 04:08:35 -0400 Received: from mail-pj1-x102d.google.com (mail-pj1-x102d.google.com [IPv6:2607:f8b0:4864:20::102d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3882B44B8 for ; Mon, 17 Apr 2023 01:08:10 -0700 (PDT) Received: by mail-pj1-x102d.google.com with SMTP id z11-20020a17090abd8b00b0024721c47ceaso11397531pjr.3 for ; Mon, 17 Apr 2023 01:08:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance.com; s=google; t=1681718889; x=1684310889; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=hr7bhkX+Epn2YWYx/+oT337obKjgENzwcgRHzhBp9VI=; b=bJXY+7hDuLaSpYXxwM/yztjf06sBYybcq8xuD8cBmDItLAyd9PmLi0XpAUmOy6xHv+ dpbs4n5YrNyNLE6256NVjkOrdAV6ktoGBOmDZ9w7UHcKgAIC3bNX800RYlnF+U6pPF5d m21gfVGUIQGEEs5qowWSv8XTYGM8zmGWtv7OcI8aqDLWt1uQ5wboTfo0EHtda091FaMw 6iUnxdRbHa9aD3jdgBxyNYqLNz1cG0soqrHKFcaTf2LvRmOHyJ/96GhZ3Rzurl4r7P1p jipg6Ig8ym6ndYHYqs4TO55xszkUOh8WKQYAKfRyxwSrUHA7J+aT64DOXYKx+0vk10q/ DqBg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1681718889; x=1684310889; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=hr7bhkX+Epn2YWYx/+oT337obKjgENzwcgRHzhBp9VI=; b=haSSJxI3QFtt98+Qbyy5zAYzp/v/m1LMT4b+SCnkWayhN4/rkCDVVwEHv8h/g7qVa5 uHgym+Nuqp7fUSVRttTVrautuP3BSZxt4KNWTMCOtVkbnz5aWePPzayFkcl/Rn65HI60 br6RTaaYm9I+wXiDh04Qi2H5IUagAJRXiTfO2FJ9DVupZ0/KOEcYDRe9bp06lloUWI38 ep/QTq/6RkjzG7XNgLZNlMD2IQP0mF9tHFaEUAIN3WRk7IulT4A5yuIL8N+tRRT+1ZmI KxZX0ueHkAdMARD7AWXYT+cZfXk+mWeOhY05aia9Ami+OiuYwQseltgAhn1WS0aX/zG2 m4Wg== X-Gm-Message-State: AAQBX9d0ThPcwsqIDvEhPgj6IGKvChfOA0dgFK90lqwuMG76C/kHqaH4 4WIjavNnJKFcL1RVsSkYiGz0Kw== X-Google-Smtp-Source: AKy350Y3sXXM1tDYSIZfPXRNb03tgaugGTrcsfNudlJlHZ3NSLoFefzqTDUv758I0MgQ0K4KVNT24g== X-Received: by 2002:a17:902:db09:b0:19e:6cb9:4c8f with SMTP id m9-20020a170902db0900b0019e6cb94c8fmr15803413plx.41.1681718889687; Mon, 17 Apr 2023 01:08:09 -0700 (PDT) Received: from C02F52LSML85.bytedance.net ([139.177.225.238]) by smtp.gmail.com with ESMTPSA id jc3-20020a17090325c300b0019a97a4324dsm7114135plb.5.2023.04.17.01.08.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 17 Apr 2023 01:08:09 -0700 (PDT) From: Feng zhou To: martin.lau@linux.dev, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, song@kernel.org, yhs@fb.com, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@google.com, haoluo@google.com, jolsa@kernel.org, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, mykolal@fb.com, shuah@kernel.org Cc: bpf@vger.kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, linux-kselftest@vger.kernel.org, yangzhenze@bytedance.com, wangdongdong.6@bytedance.com, zhouchengming@bytedance.com, zhoufeng.zf@bytedance.com Subject: [PATCH 1/2] bpf: support access variable length array of integer type Date: Mon, 17 Apr 2023 16:07:48 +0800 Message-Id: <20230417080749.39074-2-zhoufeng.zf@bytedance.com> X-Mailer: git-send-email 2.39.2 (Apple Git-143) In-Reply-To: <20230417080749.39074-1-zhoufeng.zf@bytedance.com> References: <20230417080749.39074-1-zhoufeng.zf@bytedance.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org From: Feng Zhou After this commit: bpf: Support variable length array in tracing programs (9c5f8a1008a1) Trace programs can access variable length array, but for structure type. This patch adds support for integer type. Example: Hook load_balance struct sched_domain { ... unsigned long span[]; } The access: sd->span[0]. Co-developed-by: Chengming Zhou Signed-off-by: Chengming Zhou Signed-off-by: Feng Zhou --- kernel/bpf/btf.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 027f9f8a3551..a0887ee44e89 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -6157,11 +6157,13 @@ static int btf_struct_walk(struct bpf_verifier_log *log, const struct btf *btf, if (off < moff) goto error; - /* Only allow structure for now, can be relaxed for - * other types later. - */ + /* allow structure and integer */ t = btf_type_skip_modifiers(btf, array_elem->type, NULL); + + if (btf_type_is_int(t)) + return WALK_SCALAR; + if (!btf_type_is_struct(t)) goto error;