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=-5.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 F1B5FC33CAF for ; Thu, 16 Jan 2020 17:38:06 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id 52B69246C0 for ; Thu, 16 Jan 2020 17:38:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="aoQqHHUe" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 52B69246C0 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kernel-hardening-return-17568-kernel-hardening=archiver.kernel.org@lists.openwall.com Received: (qmail 3092 invoked by uid 550); 16 Jan 2020 17:37:59 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Received: (qmail 2045 invoked from network); 16 Jan 2020 17:37:58 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579196266; bh=8SPtXhgDABdtkfo2azlbC9YC/FrYRauKdCnSEeS0iXM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=aoQqHHUeXgvXc3azh487blarI0nv3o9hiUY19N5hBxZdSanJP57l8QoyH8C3FOFjC fLQ8JocSkcenfCgyEQRD2Ifv3ibu/nrKUInfNAWFxvAldWYgdgJIldKkvBmgdKx2w0 hqYJXkIVAjhzdK2jGG3gP7p0i0lxRgVM6+nUpx58= Date: Thu, 16 Jan 2020 17:37:40 +0000 From: Will Deacon To: Sami Tolvanen Cc: Catalin Marinas , Steven Rostedt , Masami Hiramatsu , Ard Biesheuvel , Mark Rutland , Dave Martin , Kees Cook , Laura Abbott , Marc Zyngier , Nick Desaulniers , Jann Horn , Miguel Ojeda , Masahiro Yamada , clang-built-linux@googlegroups.com, kernel-hardening@lists.openwall.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v6 09/15] arm64: reserve x18 from general allocation with SCS Message-ID: <20200116173739.GA21396@willie-the-truck> References: <20191018161033.261971-1-samitolvanen@google.com> <20191206221351.38241-1-samitolvanen@google.com> <20191206221351.38241-10-samitolvanen@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191206221351.38241-10-samitolvanen@google.com> User-Agent: Mutt/1.10.1 (2018-07-13) On Fri, Dec 06, 2019 at 02:13:45PM -0800, Sami Tolvanen wrote: > Reserve the x18 register from general allocation when SCS is enabled, > because the compiler uses the register to store the current task's > shadow stack pointer. Note that all external kernel modules must also be > compiled with -ffixed-x18 if the kernel has SCS enabled. > > Signed-off-by: Sami Tolvanen > Reviewed-by: Nick Desaulniers > Reviewed-by: Kees Cook > --- > arch/arm64/Makefile | 4 ++++ > 1 file changed, 4 insertions(+) Acked-by: Will Deacon Will