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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7E3FCC433F5 for ; Tue, 4 Oct 2022 12:17:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229700AbiJDMR6 (ORCPT ); Tue, 4 Oct 2022 08:17:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53034 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229758AbiJDMR4 (ORCPT ); Tue, 4 Oct 2022 08:17:56 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7486358DF5 for ; Tue, 4 Oct 2022 05:17:51 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 12A0D613FB for ; Tue, 4 Oct 2022 12:17:50 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4D561C433C1; Tue, 4 Oct 2022 12:17:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1664885869; bh=gj+lmGiQ6/eyQbz4IlLGjbfszcAc6g1PRbRVTIskYsU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=RguyANGEv93VT/O5pLLdgIyZRInBVC1QjvFRted0g3z4shFgEIsloYX+JPEWlGjAD 2AjUNqZdGHhqNYdyzo3oRivSKHdCFcqyFBq1Ltzr9BaKFIWZ9hnErcXpIUf+9n339u uDLF0qinwEDKBsRz7uCpD2o7NCvzMqvGX+hBvxyo9mJXUYNadkyZq1E9JsN3baI6BW +yIQ3FAX3ESqkoCXwZadkXDKAxApjeYwe5apCjEM1v/qVb9GQC0T5YOp62af7nJLz5 oTsspLATT7pBumfIRQz9dqfbhYfOTTT1P/aWXQdRk2dxMSdXxgEaoP4mAr83Uhim/L 6DdeCjcd0E6GA== Received: by quaco.ghostprotocols.net (Postfix, from userid 1000) id 9263A4062C; Tue, 4 Oct 2022 09:17:47 -0300 (-03) Date: Tue, 4 Oct 2022 09:17:47 -0300 From: Arnaldo Carvalho de Melo To: Martin =?utf-8?B?TGnFoWth?= , Yonghong Song , Andrii Nakryiko Cc: dwarves@vger.kernel.org, Nick Clifton Subject: Re: Encountered error while encoding BTF due to Unsupported DW_TAG_unspecified_type(0x3b) Message-ID: References: <878d0959-7f80-471e-69d5-5228822b4365@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <878d0959-7f80-471e-69d5-5228822b4365@suse.cz> X-Url: http://acmel.wordpress.com Precedence: bulk List-ID: X-Mailing-List: dwarves@vger.kernel.org Em Mon, Oct 03, 2022 at 10:56:36AM +0200, Martin Liška escreveu: > I noticed one can't build 5.19 with latest binutils master. > > One see the following error: > [ 1413s] BTF .btf.vmlinux.bin.o > [ 1413s] Unsupported DW_TAG_unspecified_type(0x3b) > [ 1413s] Encountered error while encoding BTF. > > It's caused by DWARF coming from .S files and the change is introduced since > the following binutils revision: > > commit 5578fbf672ee497ea19826edeb509f4cc3e825a8 > Author: Nick Clifton > Date: Thu Aug 25 11:48:00 2022 +0100 > > GAS: Add a return type tag to DWARF DIEs generated for function symbols. > > for entry.S the output changes to: > > $ as-new --gdwarf-5 --64 -o entry.o entry.S && readelf -wi entry.o > Contents of the .debug_info section: > > Compilation Unit @ offset 0x0: > Length: 0x35 (32-bit) > Version: 5 > Unit Type: DW_UT_compile (1) > Abbrev Offset: 0x0 > Pointer Size: 8 > <0>: Abbrev Number: 3 (DW_TAG_unspecified_type) <--- the problematic TAG > <0>: Abbrev Number: 1 (DW_TAG_compile_unit) > DW_AT_stmt_list : 0x0 > <12> DW_AT_low_pc : 0x0 > <1a> DW_AT_high_pc : 19 > <1b> DW_AT_name : (indirect string, offset: 0x0): ../arch/x86/entry/entry.S > <1f> DW_AT_comp_dir : (indirect string, offset: 0x1a): /tmp > <23> DW_AT_producer : (indirect string, offset: 0x1f): GNU AS 2.39.50 > <27> DW_AT_language : 32769 (MIPS assembler) > <1><29>: Abbrev Number: 2 (DW_TAG_subprogram) > <2a> DW_AT_name : (indirect string, offset: 0x2e): entry_ibpb > <2e> DW_AT_external : 1 > <2e> DW_AT_type : <0xc> Ok, it happens at the top level of a CU and there are users for it, now to try to figure out how to best support this in the pretty printer, DWARF loader and BTF encoder. - Arnaldo > <2f> DW_AT_low_pc : 0x0 > <37> DW_AT_high_pc : 19 > <1><38>: Abbrev Number: 0 > > Is it something pahole should handle? > > Thanks, > Martin -- - Arnaldo