From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <mark@klomp.org>
Received: from gnu.wildebeest.org (wildebeest.demon.nl [212.238.236.112])
 by sourceware.org (Postfix) with ESMTPS id 480F33857817
 for <elfutils-devel@sourceware.org>; Wed,  8 Sep 2021 21:29:35 +0000 (GMT)
DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 480F33857817
Authentication-Results: sourceware.org;
 dmarc=none (p=none dis=none) header.from=klomp.org
Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=klomp.org
Received: from reform (deer0x11.wildebeest.org [172.31.17.147])
 (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits))
 (No client certificate requested)
 by gnu.wildebeest.org (Postfix) with ESMTPSA id 3D7C8300BC88;
 Wed,  8 Sep 2021 23:29:33 +0200 (CEST)
Received: by reform (Postfix, from userid 1000)
 id C9A302E811C5; Wed,  8 Sep 2021 23:29:33 +0200 (CEST)
Date: Wed, 8 Sep 2021 23:29:33 +0200
From: Mark Wielaard <mark@klomp.org>
To: Alexander Egorenkov <egorenar-dev@posteo.net>
Cc: elfutils-devel@sourceware.org
Subject: Re: Adding a new section to an ELF file aborts with Assertion `shdr
 != NULL'
Message-ID: <YTkrPV/07Mqo9oEC@wildebeest.org>
References: <87tuj020ro.fsf@posteo.net>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <87tuj020ro.fsf@posteo.net>
X-Spam-Status: No, score=-5.1 required=5.0 tests=BAYES_00, KAM_DMARC_STATUS,
 SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.4
X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on
 server2.sourceware.org
X-BeenThere: elfutils-devel@sourceware.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Elfutils-devel mailing list <elfutils-devel.sourceware.org>
List-Unsubscribe: <https://sourceware.org/mailman/options/elfutils-devel>,
 <mailto:elfutils-devel-request@sourceware.org?subject=unsubscribe>
List-Archive: <https://sourceware.org/pipermail/elfutils-devel/>
List-Help: <mailto:elfutils-devel-request@sourceware.org?subject=help>
List-Subscribe: <https://sourceware.org/mailman/listinfo/elfutils-devel>,
 <mailto:elfutils-devel-request@sourceware.org?subject=subscribe>
X-List-Received-Date: Wed, 08 Sep 2021 21:29:36 -0000

Hi Alex,

On Sat, Sep 04, 2021 at 08:38:51AM +0000, Alexander Egorenkov via Elfutils-devel wrote:
> i'm facing an issue with libelf when i try to add a new section to an
> ELF file.
> 
> How to reproduce the issue:
> 1. Create a simple ELF file with libelf containing only 2 sections, NULL and
> a string table
> 2. Close ELF file
> 3. Reopen the new ELF file in RW mode with libelf
> 4. Add new section with elf_newscn()
> 5. Update ELF with elf_update()
> 6. Assertion appears
> 
> The weird thing is that if i add only a new program segment then
> everything goes well. But as soon as i add a new section, it fails.
> 
> Error message:
> 
> test: elf32_updatenull.c:214: __elf64_updatenull_wrlock: Assertion `shdr
> != NULL' failed.
> 
> Any hint what i'm doing wrong ? 

I don't immediately know. Could you post the code you are using and/or
the generated file after step 2? That might make it a bit easier to
see exactly what is going on.

Thanks,

Mark