From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [63.128.21.124]) by sourceware.org (Postfix) with ESMTP id BCA9B389041C for ; Fri, 22 Jan 2021 12:42:03 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org BCA9B389041C Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-322-7-M_GnZ9MZC2ENQB-rWVcw-1; Fri, 22 Jan 2021 07:41:59 -0500 X-MC-Unique: 7-M_GnZ9MZC2ENQB-rWVcw-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id B30941572B; Fri, 22 Jan 2021 12:41:58 +0000 (UTC) Received: from tucnak.zalov.cz (ovpn-112-64.ams2.redhat.com [10.36.112.64]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 59F2B50B44; Fri, 22 Jan 2021 12:41:58 +0000 (UTC) Received: from tucnak.zalov.cz (localhost [127.0.0.1]) by tucnak.zalov.cz (8.16.1/8.16.1) with ESMTPS id 10MCfreR3895700 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Fri, 22 Jan 2021 13:41:53 +0100 Received: (from jakub@localhost) by tucnak.zalov.cz (8.16.1/8.16.1/Submit) id 10MCfqRf3895699; Fri, 22 Jan 2021 13:41:52 +0100 Date: Fri, 22 Jan 2021 13:41:52 +0100 From: Jakub Jelinek To: Mark Wielaard Cc: dwz@sourceware.org Subject: Re: [PATCH] Don't crash on DWARF5 .debug_line table with zero files. Message-ID: <20210122124152.GO4020736@tucnak> Reply-To: Jakub Jelinek References: <20210122124047.20503-1-mark@klomp.org> MIME-Version: 1.0 In-Reply-To: <20210122124047.20503-1-mark@klomp.org> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Spam-Status: No, score=-12.3 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, RCVD_IN_DNSWL_LOW, RCVD_IN_MSPIKE_H4, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: dwz@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Dwz mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 22 Jan 2021 12:42:05 -0000 On Fri, Jan 22, 2021 at 01:40:47PM +0100, Mark Wielaard wrote: > Not having any files in a DWARF5 .debug_line table is odd, but not > technically invalid. Normally there should be a zero file entry that > is equal to the compile unit main file (there is no such zero entry > for early DWARF versions and we handle no file entries fine in that > case). > > https://bugzilla.redhat.com/show_bug.cgi?id=1919243 Ok. > --- > dwz.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/dwz.c b/dwz.c > index 53b9548..28f0c4d 100644 > --- a/dwz.c > +++ b/dwz.c > @@ -1839,7 +1839,8 @@ read_debug_line (DSO *dso, dw_cu_ref cu, uint32_t off) > } > > nfiles = read_uleb128 (ptr); > - nfiles--; /* We will skip the first (zero) entry. */ > + if (nfiles > 0) > + nfiles--; /* We will skip the first (zero) entry. */ > } > > cu->cu_nfiles = nfiles; > -- > 2.18.4 Jakub