From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from esa1.mentor.iphmx.com (esa1.mentor.iphmx.com [68.232.129.153]) by sourceware.org (Postfix) with ESMTPS id F2F8A384B0C1 for ; Tue, 21 Apr 2020 21:27:31 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org F2F8A384B0C1 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=codesourcery.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=joseph_myers@mentor.com IronPort-SDR: Bxplb9vvZUrAf0NJ12RLJPApZAf75QfF2neEghnMEjL/KRjMq00bjaEvn850gy9CM3psmnE6Lf NHa9Zt8EJwceBY4wMW76Y4tZRMX8hPyk57Tvs9SIT2fnI4nbxfsM2ZCddHi5XTvvMykn3wgNc2 HC1Gg3S9K0nzX28e64+zn+ix/pX2fxRVGjT6Yh3kN3+W43HKP4FJ8HzpDOhBoeWjtbkCf2UrrV 1BmTDEIDbrx0kjJCHh5siQZGzlaIItaVMYbfStxuGmLvTCiNcKNVrlEigWcrO7GwoKj2XTspKb bj0= X-IronPort-AV: E=Sophos;i="5.72,411,1580803200"; d="scan'208";a="50101830" Received: from orw-gwy-01-in.mentorg.com ([192.94.38.165]) by esa1.mentor.iphmx.com with ESMTP; 21 Apr 2020 13:27:30 -0800 IronPort-SDR: C9d2Gty6d0AcDA/C4JGtgLhxEND1IqHSTSPtr9cCrQoB2zHvuHKB0q3MYoqiXUuCmx8TGt9X3U 6yP5hl3qe6hPRxsegpotUeY1dA/ZmMLFGu6iYwUuqc2sfcWUIGE+rOow0Jgll0pZuwEK2+4duo dpN/0UVQH95hBwAGz2go6JqlCj9rgQtJ75JD1AfQkTLtZKnKchj/G68QA0VKia4vEjfY6CwocQ jaFuYE9yDNDj7g0kiBELCKfaQ5gmJMB01x8MlOdll0szydb0l1AJa2+kKgyxij0c8no94rPFWS AfU= Date: Tue, 21 Apr 2020 21:27:25 +0000 From: Joseph Myers X-X-Sender: jsm28@digraph.polyomino.org.uk To: Florian Weimer CC: "zhuyan (M)" , "libc-alpha@sourceware.org" Subject: Re: [PATCH v2] memcpy: use bhs/bls instead of bge/blt [BZ #25620] In-Reply-To: <877dy8rjlq.fsf@mid.deneb.enyo.de> Message-ID: References: <95923e664fc9426c9c121efeaa69268c@huawei.com> <877dy8rjlq.fsf@mid.deneb.enyo.de> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" X-Originating-IP: [137.202.0.90] X-ClientProxiedBy: SVR-IES-MBX-08.mgc.mentorg.com (139.181.222.8) To svr-ies-mbx-01.mgc.mentorg.com (139.181.222.1) X-Spam-Status: No, score=-7.7 required=5.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS, KAM_DMARC_STATUS, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=no autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) 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 Apr 2020 21:27:33 -0000 On Tue, 21 Apr 2020, Florian Weimer wrote: > * Joseph Myers: > > > On Mon, 13 Apr 2020, zhuyan (M) wrote: > > > >> In ARMv7, the memcpy() implementation allows for program execution to > >> continue in scenarios where a segmentation fault or crash should have > >> occurred. The dangers occur in that subsequent execution and iterations > >> of this code will be executed with this corrupted data. > >> > >> Such as, we use 'memcpy' copy 0x80000000 byte to buffer(The buffer size > >> is 100 bytes), it didn't crash. > > > > This patch includes an architecture-specific test, specific to memcpy. > > My understanding of Wilco's request in bug 25620 was for an > > architecture-independent test or tests, covering all string functions with > > such large arguments, so we can ensure we're consistent across > > architectures. > > Sure, that would be great, but can we make this independent of this > fix, please? I think the minimum for this fix should be an architecture-independent test for memcpy (but not other string functions, and not necessarily testing all IFUNC variants of memcpy). -- Joseph S. Myers joseph@codesourcery.com