From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-1.8 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_LOW, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 3321 invoked from network); 26 May 2023 10:18:46 -0000 Received: from second.openwall.net (193.110.157.125) by inbox.vuxu.org with ESMTPUTF8; 26 May 2023 10:18:46 -0000 Received: (qmail 32710 invoked by uid 550); 26 May 2023 10:18:43 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Reply-To: musl@lists.openwall.com Received: (qmail 32675 invoked from network); 26 May 2023 10:18:42 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=inria.fr; s=dc; h=date:from:to:cc:subject:message-id:in-reply-to: references:mime-version; bh=6sB9vuSqARbKkxrcxvWzzsvhngWrCSSnYdwOgmv99R8=; b=alKoLZ/LPoI08NQ6sgl0XallLBT/UbtLQfgHJ9QSg/Kk1Ok+7M5rBJdG 5pNnXuHU9atcgvSa/Pu7JdDE6liN9HPF2ZKVyAOnBEpUUTOg0J1ehFUDB 3oDO4/sugxaa2/9cZOXasxcwO6ESW6+rytkKofCzmMTfxVlfV0Qalzo9v A=; Authentication-Results: mail3-relais-sop.national.inria.fr; dkim=none (message not signed) header.i=none; spf=SoftFail smtp.mailfrom=jens.gustedt@inria.fr; dmarc=fail (p=none dis=none) d=inria.fr X-IronPort-AV: E=Sophos;i="6.00,193,1681164000"; d="scan'208";a="57090915" Date: Fri, 26 May 2023 12:18:29 +0200 From: =?UTF-8?B?SuKCkeKCmeKCmw==?= Gustedt To: Joakim Sindholt Cc: musl@lists.openwall.com Message-ID: <20230526121829.4b9a9538@inria.fr> In-Reply-To: <20230526115236.b15f8bf97a529da07fba514f@zhasha.com> References: <20230526115236.b15f8bf97a529da07fba514f@zhasha.com> Organization: inria.fr X-Mailer: Claws Mail 4.0.0 (GTK+ 3.24.33; x86_64-pc-linux-gnu) X-Face: iVBORw0KGgoAAAANSUhEUgAAADAAAAAwBAMAAAClLOS0AAAAAXNSR0IArs4c6QAAACRQTFRFERslNjAsLTE9Ok9wUk9TaUs8iWhSrYZkj42Rz6aD3sGZ MIME-Version: 1.0 Content-Type: multipart/signed; boundary="Sig_/.N+fUQE4FWm_35maNR+loH0"; protocol="application/pgp-signature"; micalg=pgp-sha1 Subject: Re: [musl] [C23 string conversion 1/3] C23: add the new memset_explicit function --Sig_/.N+fUQE4FWm_35maNR+loH0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Joakim, on Fri, 26 May 2023 11:52:36 +0200 you (Joakim Sindholt ) wrote: > I don't see how this is in any way useful. It's certainly not part of > the standard, which only says: >=20 > > The intention is that the memory store is always performed (i.e., > > never elided), regardless of optimizations. This is in contrast to > > calls to the memset function (7.26.6.1) =20 There has been a long discussion in WG14 about this what is even possible to say here. The clear intent in all discussions was to have something that best inhibits all sorts of information leak. What you are citing is just a footnote. The normative text says: The purpose of this function is to make sensitive information stored in the object inaccessible So this is ist the expressed intent. This is clearly a QoI issue. I think that indeed a sequential reordering barrier is the minimal quality that implementations can provide. But since this is not time critical, we might be able to provide a bit more, with modest cost, such as synchronization with other threads, and such as deleting the information where even the object was located in the first place. Thanks J=E2=82=91=E2=82=99=E2=82=9B --=20 :: ICube :::::::::::::::::::::::::::::: deputy director :: :: Universit=C3=A9 de Strasbourg :::::::::::::::::::::: ICPS :: :: INRIA Nancy Grand Est :::::::::::::::::::::::: Camus :: :: :::::::::::::::::::::::::::::::::::: =E2=98=8E +33 368854536 :: :: https://icube-icps.unistra.fr/index.php/Jens_Gustedt :: --Sig_/.N+fUQE4FWm_35maNR+loH0 Content-Type: application/pgp-signature Content-Description: OpenPGP digital signature -----BEGIN PGP SIGNATURE----- iF0EARECAB0WIQSN9stI2OFN1pLljN0P0+hp2tU34gUCZHCHdgAKCRAP0+hp2tU3 4r98AJ9QZmQZ3SQl0J0f+pBYWcZkaEGIpQCeOnkf9SAIb0SIL3paENJVx3A8Lzk= =mlaZ -----END PGP SIGNATURE----- --Sig_/.N+fUQE4FWm_35maNR+loH0--