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=-13.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL autolearn=no 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 99555C433E0 for ; Thu, 14 Jan 2021 18:53:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 49E8D23B28 for ; Thu, 14 Jan 2021 18:53:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726869AbhANSx6 (ORCPT ); Thu, 14 Jan 2021 13:53:58 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37462 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725854AbhANSx6 (ORCPT ); Thu, 14 Jan 2021 13:53:58 -0500 Received: from mail-pf1-x429.google.com (mail-pf1-x429.google.com [IPv6:2607:f8b0:4864:20::429]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 500A9C0613C1 for ; Thu, 14 Jan 2021 10:53:18 -0800 (PST) Received: by mail-pf1-x429.google.com with SMTP id h10so3888097pfo.9 for ; Thu, 14 Jan 2021 10:53:18 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=etEJQyE4wI0xqWJz8agLY3zHi4W3c5fEnAfHXnXZRx4=; b=PkfoBY28Z0KZd+sJWOsFzHre7U+J5Q9Ahv42tts9JioNQsOe3PcXmNv+9C2ByJiSVS 22nAALAvEsCbETcdwhMQ3PVxhWR7R6/uD09fr/xz9+q5TdQfuDnUfpubORpm9VpkijpV gUVNVOxe1lb2kq8KQxokHVknP/g+oFDtdH4r3+LSJuxXybZBATZMh2NBmnQ22fcbzBKf YtwBSRAo3ULo2U8g1prwHLkaWKkW8qIs8IZGBxTOHA1hJwyCDzz8A/pztfAsRJXhBOsp QKaehCoC4s+sFVSyQhGcui5QhqVAtnQ8DdCQlxWAEKAo/1D3j/cbEeL/pSNlZLT3rBPQ IfXg== 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=etEJQyE4wI0xqWJz8agLY3zHi4W3c5fEnAfHXnXZRx4=; b=ZKi5nGKZQ78LAXagNPqCjhXVQ6AgKI5ou0rAmjC8GwCkHN4xLND4u0N+q5gcfZQq75 CF7qtMafOEKsT/vJzTcII2dHGMAiS5WlqzS8q5AXRGu0hAxtyWouKIEVJd4DieaiJDJY oafElVKFYRf4l+gw3aD6OmWZRGBZ6St+eQQdoFHCfI32fW7teILDiENoveq3KCDv5poY UhpoHrTQpaF8UPjigSkApWIfQII2jedKvA/HKKf/L/6yDcrRVxnhJZvXUx/IkHa0mGka GcdP6WvN52ST06172Mm2w8IM0tsBdaCQALcOWDIiBcaCEdHZ7K7Izya0TVVF5BvBqbMD sDtg== X-Gm-Message-State: AOAM531CCeGx7vsyPCl7fwYtFJaXRSpTaQgUPqjjL8WW02vtj9uHTjf8 y6A46tqschU719w3mJeDHMR1ULDPpINzL75P3tCxwg== X-Google-Smtp-Source: ABdhPJw38RHREm7Yzl2+YeiPnoudzHETWhrvYLvHmrWnfe86WnAr71gkSEfCUUdTGK65f4KE1GJr4g9I5gXheZcJEQw= X-Received: by 2002:a62:7c4a:0:b029:19d:b7bc:2c51 with SMTP id x71-20020a627c4a0000b029019db7bc2c51mr8801353pfc.30.1610650397614; Thu, 14 Jan 2021 10:53:17 -0800 (PST) MIME-Version: 1.0 References: <20201204011129.2493105-1-ndesaulniers@google.com> <20201204011129.2493105-3-ndesaulniers@google.com> In-Reply-To: From: Nick Desaulniers Date: Thu, 14 Jan 2021 10:53:06 -0800 Message-ID: Subject: Re: [PATCH v3 0/2] Kbuild: DWARF v5 support To: Sedat Dilek , Masahiro Yamada , Jiri Olsa , Andrii Nakryiko , Arnaldo Carvalho de Melo Cc: Caroline Tice , Arvind Sankar , Jakub Jelinek , Fangrui Song , Clang-Built-Linux ML , Nick Clifton , bpf Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Wed, Jan 13, 2021 at 10:18 PM Sedat Dilek wrote: > > On Wed, Jan 13, 2021 at 11:25 PM Caroline Tice wrote: > > > > On Tue, Jan 12, 2021 at 3:17 PM Sedat Dilek wrote: > >> > >> Unfortunately, I see with CONFIG_DEBUG_INFO_DWARF5=y and > >> CONFIG_DEBUG_INFO_BTF=y: > >> > >> die__process_inline_expansion: DW_TAG_INVALID (0x48) @ <0x3f0dd5a> not handled! > >> die__process_function: DW_TAG_INVALID (0x48) @ <0x3f0dd69> not handled! I can confirm that I see a stream of these warnings when building with this patch series applied, and those two configs enabled. rebuilding with `make ... V=1`, it looks like the call to: + pahole -J .tmp_vmlinux.btf is triggering these. Shall I send a v4 that adds a Kconfig dependency on !DEBUG_INFO_BTF? Does pahole have a bug tracker? > >> > >> In /usr/include/dwarf.h I found: > >> > >> 498: DW_OP_lit24 = 0x48, /* Literal 24. * > > > > > > There are multiple dwarf objects with the value 0x48, depending on which section of the dwarf.h file you search: > > > > DW_TAG_call_site = 0x48 > > DW_AT_static_link = 0x48 > > DW_OP_lit24 = 0x48. > > > > In this case, since the error message was about a DW_TAG, it would be complaining about DW_TAG_call_site, which is new to DWARF v5. > > > Example for "DW_TAG_INVALID (0x48)" from my build-log: > > die__process_inline_expansion: DW_TAG_INVALID (0x48) @ <0x1f671e7> not handled! > > $ llvm-dwarfdump-11 --debug-info=0x1f671e7 vmlinux > vmlinux: file format elf64-x86-64 > > .debug_info contents: > > 0x01f671e7: DW_TAG_call_site > DW_AT_call_return_pc (0xffffffff811b16f2) > DW_AT_call_origin (0x01f67f1d) > > Looking for "DW_AT_call_origin (0x01f67f1d)": > > $ llvm-dwarfdump-11 --debug-info=0x01f67f1d vmlinux > vmlinux: file format elf64-x86-64 > > .debug_info contents: > > 0x01f67f1d: DW_TAG_subprogram > DW_AT_external (true) > DW_AT_declaration (true) > DW_AT_linkage_name ("fput") > DW_AT_name ("fput") > DW_AT_decl_file > ("/home/dileks/src/linux-kernel/git/./include/linux/file.h") > DW_AT_decl_line (16) > DW_AT_decl_column (0x0d) That's a neat trick (using --debug-info=offset to print one element from the stream). -- Thanks, ~Nick Desaulniers