From patchwork Mon Jul 20 06:17:41 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ian Rogers X-Patchwork-Id: 1332046 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: incoming-bpf@patchwork.ozlabs.org Delivered-To: patchwork-incoming-bpf@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=bpf-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=google.com header.i=@google.com header.a=rsa-sha256 header.s=20161025 header.b=jCza9kOb; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4B9BNW4C4sz9sRW for ; Mon, 20 Jul 2020 16:17:47 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726611AbgGTGRq (ORCPT ); Mon, 20 Jul 2020 02:17:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36178 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726015AbgGTGRp (ORCPT ); Mon, 20 Jul 2020 02:17:45 -0400 Received: from mail-pj1-x1049.google.com (mail-pj1-x1049.google.com [IPv6:2607:f8b0:4864:20::1049]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8ED71C0619D4 for ; Sun, 19 Jul 2020 23:17:45 -0700 (PDT) Received: by mail-pj1-x1049.google.com with SMTP id bf1so12840684pjb.6 for ; Sun, 19 Jul 2020 23:17:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc; bh=hrTZ3ILM0xAvfuFOaXWaqEFvmBYS4j5nhBs2MogC2d4=; b=jCza9kObWWd7hRrzAmTOlTIznNK5au/+obW9N2t3FEDENVbFaIuGNwvI+czZfkkjfj yz5Acv84a48iP3jdHNxPq9oYAQ3JsaCd43nn72tDwiAb0KzKjz0D1eRaxZPmSvNI3v5p 14yBIbxUS2mz1cy/VgcYLfGAwLfyPgaeo6KCWa24lFD8fcp2A8oN/a5lernNHq87QTsg uJDXeoEKZy1wotyY285VjM6pvyZt7ZdO0ouJqrQBQpT/blmMz44W6ZUa2RD3iVc6yJ3b 7Xl+rFZB34WWL6EpieqghLEjm+gNI2iCaVcFn7br2mXNH9ssLJR3SbfkLhib6q4xprWM isOg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=hrTZ3ILM0xAvfuFOaXWaqEFvmBYS4j5nhBs2MogC2d4=; b=THx2LCo6q8t3ZF3dpfda7VfumtbFSgA+TBrBC4oKu19fK9qgXi2jBZOEJodLS3sMji bTnmA24R0/uFCyQlUsJn2OOUctXaPuEK+wArdH/ocUa/CXS+xPDnoZGPKptzDPPjUII2 UNTmQhTQj6GJ+f+GkrdZpYMPP6ZVBUUO+pD18zcHojC9z9PcmU2xfg22xIwwCH++qZP+ FJCaErj3vKTIW0hv4oZGQFyqfC2NDd1Gi+NWW0z3xVkuJ0C+np2Z2IUE3Czm3d/R8Twc DyozdlPtJoTTIQTFK4kEAIcY3hecfbGDO/sgzajhi/67m3hrqpqtA1lCsv9CNLMKey3+ IoaQ== X-Gm-Message-State: AOAM531wTXO+lVq9HRppoctKA9QhIrzmnDjjub+e6WktQuiV1Scr89Rc 4EVys/tpYcB9ZA3XVvPdvDjsYnpB3/kA X-Google-Smtp-Source: ABdhPJxZ8KghvpQ17ZJUvd8FHOaqBfl50iarL4t96zD8AY8mjE1sgffczbDNvDrTORIDxuIPH0nKQjc6wtWJ X-Received: by 2002:a17:902:b78b:: with SMTP id e11mr16332011pls.204.1595225864907; Sun, 19 Jul 2020 23:17:44 -0700 (PDT) Date: Sun, 19 Jul 2020 23:17:41 -0700 Message-Id: <20200720061741.1514673-1-irogers@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.28.0.rc0.105.gf9edc3c819-goog Subject: [PATCH v2] libbpf bpf_helpers: Use __builtin_offsetof for offsetof From: Ian Rogers To: Alexei Starovoitov , Daniel Borkmann , Martin KaFai Lau , Song Liu , Yonghong Song , Andrii Nakryiko , John Fastabend , KP Singh , netdev@vger.kernel.org, bpf@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Stanislav Fomichev , Ian Rogers Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org The non-builtin route for offsetof has a dependency on size_t from stdlib.h/stdint.h that is undeclared and may break targets. The offsetof macro in bpf_helpers may disable the same macro in other headers that have a #ifdef offsetof guard. Rather than add additional dependencies improve the offsetof macro declared here to use the builtin that is available since llvm 3.7 (the first with a BPF backend). Signed-off-by: Ian Rogers Acked-by: Andrii Nakryiko --- tools/lib/bpf/bpf_helpers.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/lib/bpf/bpf_helpers.h b/tools/lib/bpf/bpf_helpers.h index a510d8ed716f..bc14db706b88 100644 --- a/tools/lib/bpf/bpf_helpers.h +++ b/tools/lib/bpf/bpf_helpers.h @@ -40,7 +40,7 @@ * Helper macro to manipulate data structures */ #ifndef offsetof -#define offsetof(TYPE, MEMBER) ((size_t)&((TYPE *)0)->MEMBER) +#define offsetof(TYPE, MEMBER) __builtin_offsetof(TYPE, MEMBER) #endif #ifndef container_of #define container_of(ptr, type, member) \