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=-9.6 required=3.0 tests=BAYES_00,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=unavailable 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 7659DC55179 for ; Wed, 21 Oct 2020 15:35:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BAF1D2177B for ; Wed, 21 Oct 2020 15:35:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="YpQWMZgc" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2502616AbgJUPfs (ORCPT ); Wed, 21 Oct 2020 11:35:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47288 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2502569AbgJUPfr (ORCPT ); Wed, 21 Oct 2020 11:35:47 -0400 Received: from mail-yb1-xb43.google.com (mail-yb1-xb43.google.com [IPv6:2607:f8b0:4864:20::b43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4979DC0613CE; Wed, 21 Oct 2020 08:35:46 -0700 (PDT) Received: by mail-yb1-xb43.google.com with SMTP id l15so2156267ybp.2; Wed, 21 Oct 2020 08:35:46 -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=D5/xCGnHx7slidVcpzEBSRP7yklPajwRiNS892kQv04=; b=YpQWMZgclARfg79AZH8x5LVSx//nNzx+8850kPMje6Trst53hiRgi92+WB/B0LGPW+ fpsa7d4KFQmwNNpoV17Uqma21rnuDcbBmiGXVJm+XglGXxVuiVt7ASPHvWlKH1wbdqkX w1171aC7KetdR1nnBIH49Y0qVLzHyFsOXpuqRsV2awl4c19AWtFJGM1CSZ8QeyjR1pt7 8ll4rxPPxWYfpCi66htOkgG24VugCmJYx8UEem2arWPBLoqMF7urjto4Yr/qHNxQ039i j/3+xYGB01vxooNkKs/08iEDbjqYBvSgSrpgwve7FMePeaO7JraeJ5W7gloBdGYTaB5V JBoA== 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=D5/xCGnHx7slidVcpzEBSRP7yklPajwRiNS892kQv04=; b=rh4SIMEoOanxBa4rjoZz3jhd1VXJeNwWn1SKgWS4qG+OoDzSDEAEF+sVYAXK8Uy1BW nFTp0hFtUUD3zINQFE6Xz1SrxCAMnQzLyJuh2stK+bowPd6Tm3Dmp5pvhEu6rQ+9J3uS RlpObpaK8fc0a3lRLrrnDC96PamCDRxhGV99EPP5WOu94fkhUu6C7C6qmMClnFN89TXm kvAvhEbDpokXJJl914hYFnwuSl6u7NFE7NVCWNUiXtE6GAG6sY/9X1xb+gdXk4pUMbcd +JXdlQ3t81cgYmqeLxAiJ4AhHK8UGG/R2zYdbVyxtsFFNUuKJr7TKDVbiFzr1kmDVn7j Unkw== X-Gm-Message-State: AOAM531+DNEBqgH2D9m0EcNSWJ3jK0cH2MANLiRV2lFOxPfnyBilQqun lM53RjFWD2OAqh/Z3Ov+2w/s9kOI88nFvso3O4Y= X-Google-Smtp-Source: ABdhPJyo+sR7bI5EENrfC2u9qIQ0dZr/cb77WxMoucEGZmSaHzxeEia1oD8Rh9xjeS9Lxpd3CfBIV4tN5v/A/+pmugw= X-Received: by 2002:a25:c001:: with SMTP id c1mr5773484ybf.27.1603294545464; Wed, 21 Oct 2020 08:35:45 -0700 (PDT) MIME-Version: 1.0 References: <20201009192607.699835-1-andrii@kernel.org> In-Reply-To: <20201009192607.699835-1-andrii@kernel.org> From: Andrii Nakryiko Date: Wed, 21 Oct 2020 08:35:34 -0700 Message-ID: Subject: Re: [PATCH dwarves] btf_loader: handle union forward declaration properly To: Andrii Nakryiko Cc: dwarves@vger.kernel.org, Arnaldo Carvalho de Melo , bpf , Kernel Team , Alexei Starovoitov Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Fri, Oct 9, 2020 at 12:26 PM Andrii Nakryiko wrote: > > Differentiate between struct and union forwards. For BTF_KIND_FWD this is > determined by kflag. So teach btf_loader to use that bit to decide whether > forward is for union or struct. > > Signed-off-by: Andrii Nakryiko > --- > N.B. This patch is based on top of tmp.libbtf_encoder branch. > > Also seems like non-forward declared union has a slightly different > representation from struct (class). Not sure why it is so, but this change > doesn't seem to break anything. > --- Ping on this one, let's include it with upcoming pahole 1.19 as well? > > btf_loader.c | 9 +++++---- > 1 file changed, 5 insertions(+), 4 deletions(-) > > diff --git a/btf_loader.c b/btf_loader.c > index 9b5da3a4997a..0cb23967fec3 100644 > --- a/btf_loader.c > +++ b/btf_loader.c > @@ -134,12 +134,13 @@ static struct type *type__new(uint16_t tag, strings_t name, size_t size) > return type; > } > > -static struct class *class__new(strings_t name, size_t size) > +static struct class *class__new(strings_t name, size_t size, bool is_union) > { > struct class *class = tag__alloc(sizeof(*class)); > + uint32_t tag = is_union ? DW_TAG_union_type : DW_TAG_structure_type; > > if (class != NULL) { > - type__init(&class->type, DW_TAG_structure_type, name, size); > + type__init(&class->type, tag, name, size); > INIT_LIST_HEAD(&class->vtable); > } > > @@ -228,7 +229,7 @@ static int create_members(struct btf_elf *btfe, const struct btf_type *tp, > > static int create_new_class(struct btf_elf *btfe, const struct btf_type *tp, uint32_t id) > { > - struct class *class = class__new(tp->name_off, tp->size); > + struct class *class = class__new(tp->name_off, tp->size, false); > int member_size = create_members(btfe, tp, &class->type); > > if (member_size < 0) > @@ -313,7 +314,7 @@ static int create_new_subroutine_type(struct btf_elf *btfe, const struct btf_typ > > static int create_new_forward_decl(struct btf_elf *btfe, const struct btf_type *tp, uint32_t id) > { > - struct class *fwd = class__new(tp->name_off, 0); > + struct class *fwd = class__new(tp->name_off, 0, btf_kind(tp)); > > if (fwd == NULL) > return -ENOMEM; > -- > 2.24.1 >