From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by sourceware.org (Postfix) with ESMTPS id F060A3858C53 for ; Wed, 20 Apr 2022 11:57:37 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org F060A3858C53 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id A6279B81D0B; Wed, 20 Apr 2022 11:57:36 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1E26CC385A0; Wed, 20 Apr 2022 11:57:32 +0000 (UTC) Date: Wed, 20 Apr 2022 12:57:29 +0100 From: Mark Brown To: Catalin Marinas Cc: Will Deacon , Kees Cook , linux-arm-kernel@lists.infradead.org, jeremy.linton@arm.com, hjl.tools@gmail.com, libc-alpha@sourceware.org, szabolcs.nagy@arm.com, yu-cheng.yu@intel.com, ebiederm@xmission.com, linux-arch@vger.kernel.org Subject: Re: [PATCH v13 0/2] arm64: Enable BTI for the executable as well as the interpreter Message-ID: References: <20220419105156.347168-1-broonie@kernel.org> <165043278356.1481705.13924459838445776007.b4-ty@chromium.org> <20220420093612.GB6954@willie-the-truck> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="zG9v52qNjk+n4FZO" Content-Disposition: inline In-Reply-To: X-Cookie: Will it improve my CASH FLOW? X-Spam-Status: No, score=-5.3 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, SPF_HELO_NONE, SPF_PASS, TXREP, T_SCC_BODY_TEXT_LINE 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: Wed, 20 Apr 2022 11:57:39 -0000 --zG9v52qNjk+n4FZO Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Wed, Apr 20, 2022 at 10:57:30AM +0100, Catalin Marinas wrote: > On Wed, Apr 20, 2022 at 10:36:13AM +0100, Will Deacon wrote: > > Kees, please can you drop this series while Catalin's alternative solution > > is under discussion (his Reviewed-by preceded the other patches)? > > https://lore.kernel.org/r/20220413134946.2732468-1-catalin.marinas@arm.com > > Both series expose new behaviours to userspace and we don't need both. > I agree. Even though the patches have my reviewed-by, I think we should > postpone them until we figure out a better W^X solution that does not > affect BTI (and if we can't, we revisit these patches). Indeed. I had been expecting this to follow the pattern of the previous nine months or so and be mostly ignored for the time being while Catalin's new series goes forward. Now that it's applied it might be worth keeping the first patch still in case someone else needs it but the second patch can probably wait. > Arguably, the two approaches are complementary but the way this series > turned out is for the BTI on main executable to be default off. I have a > worry that the feature won't get used, so we just carry unnecessary code > in the kernel. Jeremy also found this approach less than ideal: > https://lore.kernel.org/r/59fc8a58-5013-606b-f544-8277cda18e50@arm.com I'm not sure there was a fundamental concern with the approach there but rather some pushback on the instance on turning it off by default. --zG9v52qNjk+n4FZO Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAmJf9SgACgkQJNaLcl1U h9AKrwf/dbhZCV9DolWbMGrRvjZ6W88kCdrkBx+QKWt/qcCBTb1yGXjSRwHtT863 pxjPcYsckAsXSWJBV8CcdrHjhpCt+8QSVXP+YNbi7q1pCArXstG6OsmNdp7oN6Bk pmMnHaUl2sTn3NxLZGcJn4NktyDT2oC3eHFOrcIssITKrWOjwnQuXCGkAIIMs0p9 MbOT+ThUNDK04nUrtPpSAZLbmtEDtQIlNgRuXzwVYKV0vShsBzlSCbHF6dWSlTT6 Ma019h0yrN6tEyeBZGk1EhpOURYHaZQ8CtpHdD9ct4DcDUVaSVwbk3wBxwkcjro9 KcwtCYR6CMY5W/4cxs5F+H8MWFtt7w== =6YyW -----END PGP SIGNATURE----- --zG9v52qNjk+n4FZO--