From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id ED827C433ED for ; Wed, 28 Apr 2021 17:41:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A2D3C61621 for ; Wed, 28 Apr 2021 17:41:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242857AbhD1Rlw (ORCPT ); Wed, 28 Apr 2021 13:41:52 -0400 Received: from mail.kernel.org ([198.145.29.99]:54986 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242378AbhD1Rlp (ORCPT ); Wed, 28 Apr 2021 13:41:45 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id C513761446; Wed, 28 Apr 2021 17:40:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1619631641; bh=Il5tb9B4/yJVnn+I749OEcDsob5dIs8bK4SoPVj4oLM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Z2IX/RK89FpMhNMgmvKfk7GdGnPSsv1gmKMsmPe+tZgibli+eVm54a4Mkx2w4AtaJ SD9c6yFU0h/SRhPJYy87aQPyXr0QMapxuJgzngK+Xe2Czu6GccWyQpQ9TCOh/R8Szu RjIsvwk3D9EeAwnRgdHjmebckV1QKCcrMXalEuq8SYkrvv5uw1dHL5m7dpZedh5dnL xycuAafw9i5VW/N+K7s5GueJfhqZhxHVgqlG+vurBgfRiufOuR3414SdrOQMvlEOwv Rde+kZpM1ThzZPbr8rqmR3u4Z9KZMkcFPviltHogeUgwafwfc6l4s9hXkyeoone/iZ dW8sSfXqiUpHA== Date: Wed, 28 Apr 2021 18:40:10 +0100 From: Mark Brown To: Catalin Marinas Cc: Bill Wendling , Kees Cook , Ard Biesheuvel , Will Deacon , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Szabolcs Nagy , Daniel Kiss Subject: Re: [PATCH] arm64/vdso: Discard .note.gnu.property sections in vDSO Message-ID: <20210428174010.GA4593@sirena.org.uk> References: <20210423205159.830854-1-morbo@google.com> <20210428172847.GC4022@arm.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="HcAYCG3uE/tztfnV" Content-Disposition: inline In-Reply-To: <20210428172847.GC4022@arm.com> X-Cookie: System checkpoint complete. User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --HcAYCG3uE/tztfnV Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Wed, Apr 28, 2021 at 06:28:47PM +0100, Catalin Marinas wrote: > On Fri, Apr 23, 2021 at 01:51:59PM -0700, Bill Wendling wrote: > > Since the note.gnu.property section in the vDSO is not checked by the > > dynamic linker, discard the .note.gnu.property sections in the vDSO. > Can we not instead fix the linker script to preserve the > .note.gnu.property, correctly aligned? It doesn't take much space and > while we don't use it now, it has the BTI information about the binary. > Cc'ing a few others who were involved in the BTI support. Not just BTI, we also flag PAC usage in there too and could add other extensions going forwards. While the note isn't actively used by anything right now due to the kernel mapping the vDSO prior to userspace starting it is part of the ABI and something could end up wanting to use it and getting confused if it's not there. It would be much better to fix the alignment issue. --HcAYCG3uE/tztfnV Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAmCJnfkACgkQJNaLcl1U h9AMeQf+JjCPE1mknCrwwNnvPnXcUenU0DeOnChJJgTGhQGIe4ovug+jvSsiDRvp GKEOeeNYh3E2iABmqi46Ysc2bcVnzsivqsjXnlMGQP857+jnMgwh3lktKmQueL8P XgEHWN4fT2k6+tPbREAUVkYqBHWz3VhKXNt44qEw0Byn3WchMMBfuX7HkN6H6CzR 60nUXcfnyX4u51TMrefOlakdvAOV21g2Qy37DuLjSGS9A2M/ojsEKQzDbWqG88t7 ZU/FGiybkObxq0DPXJtzVXU5JxYVeRprwdHuyx6jHLGd5v9M/x6TAzMRx6i6KrhS kpuM+XkFWP1W7DlH2ECcQ9UY6E/qTg== =1KEY -----END PGP SIGNATURE----- --HcAYCG3uE/tztfnV--