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 EEBEB3858C2C for ; Tue, 21 Dec 2021 14:45:21 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org EEBEB3858C2C Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-499-A4xmnenvO0OZdHWp2zwuNA-1; Tue, 21 Dec 2021 09:45:17 -0500 X-MC-Unique: A4xmnenvO0OZdHWp2zwuNA-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 17B6810199BE; Tue, 21 Dec 2021 14:45:16 +0000 (UTC) Received: from oldenburg.str.redhat.com (unknown [10.39.192.104]) by smtp.corp.redhat.com (Postfix) with ESMTPS id D130E6AB9A; Tue, 21 Dec 2021 14:44:56 +0000 (UTC) From: Florian Weimer To: Adhemerval Zanella Cc: libc-alpha@sourceware.org, John Mellor-Crummey , Ben Woodard Subject: Re: [PATCH v6 19/20] elf: Fix runtime linker auditing on aarch64 (BZ #26643) References: <20211115183734.531155-1-adhemerval.zanella@linaro.org> <20211115183734.531155-20-adhemerval.zanella@linaro.org> <87zgovc68b.fsf@oldenburg.str.redhat.com> Date: Tue, 21 Dec 2021 15:44:54 +0100 In-Reply-To: (Adhemerval Zanella's message of "Tue, 21 Dec 2021 11:33:52 -0300") Message-ID: <87mtku9fvd.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 10.5.11.16 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain 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_H3, 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: Tue, 21 Dec 2021 14:45:23 -0000 * Adhemerval Zanella: > On 20/12/2021 18:32, Florian Weimer wrote: >> * Adhemerval Zanella: >> >>> diff --git a/elf/rtld.c b/elf/rtld.c >>> index 29a37f51d3..1a13ae6314 100644 >>> --- a/elf/rtld.c >>> +++ b/elf/rtld.c >>> @@ -990,10 +990,10 @@ file=%s [%lu]; audit interface function la_version returned zero; ignored.\n", >>> return; >>> } >>> >>> - if (lav > LAV_CURRENT) >>> + if (lav != LAV_CURRENT) >>> { >>> _dl_debug_printf ("\ >>> -ERROR: audit interface '%s' requires version %d (maximum supported version %d); ignored.\n", >>> +ERROR: audit interface '%s' requires version %d (current supported version %d); ignored.\n", >>> name, lav, LAV_CURRENT); >>> unload_audit_module (dlmargs.map, original_tls_idx); >>> return; >> >> Sorry, this is not what I had in mind. I'd like to increase LAV_CURRENT >> and pretend that the old and new versions have the same behavior, at >> least as far as aarch64 is concerned. We need not write the >> compatibility code for the old at this time, only if there >> actual users out there that demand it. > > Do you mean to only check if lav >= LAV_CURRENT and allow old audit modules > as well? Yes. > At least for aarch64 old audit modules are error-prone and potentially adds > more subtle issues since they do not save/restore some return register that > I don't see any real gain to keep supporting them. I disagree. la_objsearch alone is a significant use case, and I don't see why it wouldn't work today. It does not need any architecture-specific code whatsoever. Thanks, Florian