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 [170.10.129.124]) by sourceware.org (Postfix) with ESMTPS id 95B4A3858405 for ; Mon, 15 Nov 2021 19:01:50 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 95B4A3858405 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-273-y4jcy1WlMaGCPm5jVbf4tA-1; Mon, 15 Nov 2021 14:01:49 -0500 X-MC-Unique: y4jcy1WlMaGCPm5jVbf4tA-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 0C91E1006AA1; Mon, 15 Nov 2021 19:01:48 +0000 (UTC) Received: from oldenburg.str.redhat.com (unknown [10.39.194.81]) by smtp.corp.redhat.com (Postfix) with ESMTPS id C64B919E7E; Mon, 15 Nov 2021 19:01:46 +0000 (UTC) From: Florian Weimer To: Adhemerval Zanella Cc: libc-alpha@sourceware.org, John Mellor-Crummey , Ben Woodard Subject: Re: [PATCH v6 01/20] elf: Suppress audit calls when a (new) namespace is empty (BZ #28062) References: <20211115183734.531155-1-adhemerval.zanella@linaro.org> <20211115183734.531155-2-adhemerval.zanella@linaro.org> Date: Mon, 15 Nov 2021 20:01:44 +0100 In-Reply-To: <20211115183734.531155-2-adhemerval.zanella@linaro.org> (Adhemerval Zanella's message of "Mon, 15 Nov 2021 15:37:15 -0300") Message-ID: <87ee7hfdk7.fsf@oldenburg.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.2 (gnu/linux) MIME-Version: 1.0 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=utf-8 Content-Transfer-Encoding: quoted-printable X-Spam-Status: No, score=-12.6 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_NONE, 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: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 15 Nov 2021 19:01:51 -0000 * Adhemerval Zanella: > For a new Lmid_t the namespace link_map list are empty, so it requires > to check if before using it. This can happen for when audit module > is used along with dlmopen. Looks like you forgot to update the commit message. My patch linter also flags these: + pid_t (*s)(void) =3D xdlsym (h, "getpid"); + int (*foo)(void) =3D xdlsym (h, "foo"); Missing space before =E2=80=9C(void)=E2=80=9D. > diff --git a/elf/dl-load.c b/elf/dl-load.c > index 9f4fa9617d..9538bcb7dc 100644 > --- a/elf/dl-load.c > +++ b/elf/dl-load.c > @@ -1515,6 +1479,42 @@ cannot enable executable stack as shared object re= quires"); > /* Now that the object is fully initialized add it to the object list.= */ > _dl_add_to_namespace_list (l, nsid); > =20 > + /* Signal that we are going to add new objects. */ > + if (r->r_state =3D=3D RT_CONSISTENT) > + { > +#ifdef SHARED > + /* Auditing checkpoint: we are going to add new objects. */ > + if ((mode & __RTLD_AUDIT) =3D=3D 0 > +=09 && __glibc_unlikely (GLRO(dl_naudit) > 0)) > +=09{ > +=09 struct link_map *head =3D GL(dl_ns)[nsid]._ns_loaded; > +=09 /* Do not call the functions for any auditing object. */ > +=09 if (head->l_auditing =3D=3D 0) > +=09 { > +=09 struct audit_ifaces *afct =3D GLRO(dl_audit); > +=09 for (unsigned int cnt =3D 0; cnt < GLRO(dl_naudit); ++cnt) > +=09=09{ > +=09=09 if (afct->activity !=3D NULL) > +=09=09 afct->activity (&link_map_audit_state (head, cnt)->cookie, > +=09=09=09=09 LA_ACT_ADD); > + > +=09=09 afct =3D afct->next; > +=09=09} > +=09 } > +=09} > +#endif Please add a comment that this happens after _dl_add_to_namespace_list, so that the namespace is guaranteed not to be empty. Thanks, Florian