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 X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B08B0C47404 for ; Sat, 5 Oct 2019 18:41:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8317C222CE for ; Sat, 5 Oct 2019 18:41:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="uTCTX9by" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387791AbfJESly (ORCPT ); Sat, 5 Oct 2019 14:41:54 -0400 Received: from mail-qt1-f194.google.com ([209.85.160.194]:44375 "EHLO mail-qt1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387862AbfJESlx (ORCPT ); Sat, 5 Oct 2019 14:41:53 -0400 Received: by mail-qt1-f194.google.com with SMTP id u40so13394206qth.11; Sat, 05 Oct 2019 11:41:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=9GAtLPAKcs7RSvLMy/hhZz5WPBQSBJn2oCBqOEurUPM=; b=uTCTX9bys1iU79t/ZCGPGhPoBiqolYJTjCqyNWizzRpiY0LnK48vDaD1mgagjiqxib cktQJ9qdgETog7qw8vfoGR0EO83x1F50ZMN8P+8q/8100IURU/cSDYtdKomXzpSQoX9e 8HOiN1Goj5eIL7S8HrVHFnNQvwRJJY0zrnA0VHvjCKG5Z5pnrob+aY+4nl1OWN9nCvqo YdwG2Diy0txbOQbHiI9/exMbtPN0fAkFgNkpiMwovvK97x3auFZ8VuFWCJqjngMOUvrV rVpUIhWcq+qzdlKzZMcJu8E+RtllhjDbS4WVCjF+RPeZHWYylaQv/KIoIDIaBSUOv7IT 0YeQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=9GAtLPAKcs7RSvLMy/hhZz5WPBQSBJn2oCBqOEurUPM=; b=cjEUT8WsIgzHbOMJ6D17XtELEUV0g5PsV80D7ScpS+fbZyJahyKD+dLvF2R9gXXODo kze04L4tumrYZwTKb9XsvL8qkCVjLLNbNwhhruZEWwjDPd0ecwfbexyh3rnwDKNaQVpC 5IKJmkgRV/vjnsgq1K0uhLp9YI3iP2mt3VmkbjWcka1CAbjcOH3ZDHhkyMNBcWXADSwy f16aRiPrr+YcBRyFpljIAwgBNFjIBfaAWd5m81IYTwPcY6jBAE2Jc5Fo9cOUppfxg5O/ 9ywttz3S6bdQ25KTKjnC84ZDI8uu+SxuoMhGGT3ZFTeJlAajMYh+XSgtLUL/4zhPrXzT tPxQ== X-Gm-Message-State: APjAAAU/c8fBhzYFQBuCjt6vt12vtewcUuGF8Lkp5z92Pn9Ac5O79You gPJmNkfqVmNIjW7eV8WFPCUQuKdZMR/uMcTOqxk= X-Google-Smtp-Source: APXvYqxQyyWre1ksPo/Wn9LQuSe1PyG2SoA4JnvEHQ+h5maAz1LfL2kJLQ57np694I2oH1sWOWJSVwscU9yPDKtyr0w= X-Received: by 2002:a05:6214:281:: with SMTP id l1mr19935061qvv.224.1570300912715; Sat, 05 Oct 2019 11:41:52 -0700 (PDT) MIME-Version: 1.0 References: <20191005050314.1114330-1-ast@kernel.org> <20191005050314.1114330-3-ast@kernel.org> In-Reply-To: <20191005050314.1114330-3-ast@kernel.org> From: Andrii Nakryiko Date: Sat, 5 Oct 2019 11:41:40 -0700 Message-ID: Subject: Re: [PATCH bpf-next 02/10] bpf: add typecast to bpf helpers to help BTF generation To: Alexei Starovoitov Cc: "David S. Miller" , Daniel Borkmann , x86@kernel.org, Networking , bpf , Kernel Team Content-Type: text/plain; charset="UTF-8" Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Fri, Oct 4, 2019 at 10:05 PM Alexei Starovoitov wrote: > > When pahole converts dwarf to btf it emits only used types. > Wrap existing bpf helper functions into typedef and use it in > typecast to make gcc emits this type into dwarf. > Then pahole will convert it to btf. > The "btf_#name_of_helper" types will be used to figure out > types of arguments of bpf helpers. > The generate code before and after is the same. > Only dwarf and btf are different. > > Signed-off-by: Alexei Starovoitov > --- It's amazing this works :) Acked-by: Andrii Nakryiko > include/linux/filter.h | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/include/linux/filter.h b/include/linux/filter.h > index 2ce57645f3cd..d3d51d7aff2c 100644 > --- a/include/linux/filter.h > +++ b/include/linux/filter.h > @@ -464,10 +464,11 @@ static inline bool insn_is_zext(const struct bpf_insn *insn) > #define BPF_CALL_x(x, name, ...) \ > static __always_inline \ > u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__)); \ > + typedef u64 (*btf_##name)(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__)); \ > u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__)); \ > u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__)) \ > { \ > - return ____##name(__BPF_MAP(x,__BPF_CAST,__BPF_N,__VA_ARGS__));\ > + return ((btf_##name)____##name)(__BPF_MAP(x,__BPF_CAST,__BPF_N,__VA_ARGS__));\ > } \ > static __always_inline \ > u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__)) > -- > 2.20.0 >