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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, 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 690BAC5DF61 for ; Tue, 5 Nov 2019 20:50:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3459F214B2 for ; Tue, 5 Nov 2019 20:50:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729809AbfKEUt6 (ORCPT ); Tue, 5 Nov 2019 15:49:58 -0500 Received: from foss.arm.com ([217.140.110.172]:32788 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727888AbfKEUt5 (ORCPT ); Tue, 5 Nov 2019 15:49:57 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id DEAD111B3; Tue, 5 Nov 2019 12:49:56 -0800 (PST) Received: from lakrids.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 9AD203FB7F; Tue, 5 Nov 2019 01:04:38 -0800 (PST) Date: Tue, 5 Nov 2019 09:04:26 +0000 From: Mark Rutland To: Sami Tolvanen Cc: Will Deacon , Catalin Marinas , Steven Rostedt , Masami Hiramatsu , Ard Biesheuvel , Dave Martin , Kees Cook , Laura Abbott , Marc Zyngier , Nick Desaulniers , Jann Horn , Miguel Ojeda , Masahiro Yamada , clang-built-linux , Kernel Hardening , linux-arm-kernel , LKML Subject: Re: [PATCH v4 10/17] arm64: disable kretprobes with SCS Message-ID: <20191105090426.GA4743@lakrids.cambridge.arm.com> References: <20191018161033.261971-1-samitolvanen@google.com> <20191101221150.116536-1-samitolvanen@google.com> <20191101221150.116536-11-samitolvanen@google.com> <20191104170454.GA2024@lakrids.cambridge.arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.11.1+11 (2f07cb52) (2018-12-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 04, 2019 at 03:42:09PM -0800, Sami Tolvanen wrote: > On Mon, Nov 4, 2019 at 9:05 AM Mark Rutland wrote: > > I'm a bit confused as to why that's the case -- could you please > > elaborate on how this is incompatible? > > > > IIUC kretrobes works by patching the function entry point with a BRK, so > > that it can modify the LR _before_ it is saved to the stack. I don't see > > how SCS affects that. > > You're correct. While this may not be optimal for reducing attack > surface, I just tested this to confirm that there's no functional > conflict. I'll drop this and related patches from v5. Great; thanks for confirming! Mark. 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=-2.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,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 A188AC5DF60 for ; Tue, 5 Nov 2019 20:50:03 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 4544121D6C for ; Tue, 5 Nov 2019 20:50:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="kK07xQ9h" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4544121D6C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=V0YoW8gMpBs6Me2HMM5Y+ihpATnszg3TVr/5WhzWa8M=; b=kK07xQ9hvklwtk 3nE6ZK5ujn693F9gfWvk4mDTMBhZVK6hgRhLSodUpWTSaC93NErU0xmau9UNO2mqurtDu9wo6Gg5J BuuC+0u01l1JWI7TRLlfNgax2CVzrtMzex0X4Drq1uPn5az8V7PohN5WzhxMF1y3cTUelZ5WD7G8X mVP9aX6GrcrBvBwtxQ/P+jcBR5F+RENmFRk5CPHQpTgG9fyDw1k4jkfQB5che8alOQmlcMWvxGg/4 orct8Z6l1hLIb7Ugfhw9ej4xi1OQ4LaJzMxpUY2mliyITFfeE9ie4ava9+g2D/xhBOHr91SYPWP+H nW6IEVS1DOCoGHEZaRSA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1iS5m5-0008II-EM; Tue, 05 Nov 2019 20:50:01 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1iS5m1-0008HM-Pk for linux-arm-kernel@lists.infradead.org; Tue, 05 Nov 2019 20:49:59 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id DEAD111B3; Tue, 5 Nov 2019 12:49:56 -0800 (PST) Received: from lakrids.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 9AD203FB7F; Tue, 5 Nov 2019 01:04:38 -0800 (PST) Date: Tue, 5 Nov 2019 09:04:26 +0000 From: Mark Rutland To: Sami Tolvanen Subject: Re: [PATCH v4 10/17] arm64: disable kretprobes with SCS Message-ID: <20191105090426.GA4743@lakrids.cambridge.arm.com> References: <20191018161033.261971-1-samitolvanen@google.com> <20191101221150.116536-1-samitolvanen@google.com> <20191101221150.116536-11-samitolvanen@google.com> <20191104170454.GA2024@lakrids.cambridge.arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.11.1+11 (2f07cb52) (2018-12-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191105_124957_878541_FAE273A2 X-CRM114-Status: GOOD ( 12.84 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kees Cook , Ard Biesheuvel , Masahiro Yamada , Catalin Marinas , Jann Horn , Nick Desaulniers , LKML , Steven Rostedt , Miguel Ojeda , clang-built-linux , Masami Hiramatsu , Marc Zyngier , Kernel Hardening , Laura Abbott , Will Deacon , Dave Martin , linux-arm-kernel Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, Nov 04, 2019 at 03:42:09PM -0800, Sami Tolvanen wrote: > On Mon, Nov 4, 2019 at 9:05 AM Mark Rutland wrote: > > I'm a bit confused as to why that's the case -- could you please > > elaborate on how this is incompatible? > > > > IIUC kretrobes works by patching the function entry point with a BRK, so > > that it can modify the LR _before_ it is saved to the stack. I don't see > > how SCS affects that. > > You're correct. While this may not be optimal for reducing attack > surface, I just tested this to confirm that there's no functional > conflict. I'll drop this and related patches from v5. Great; thanks for confirming! Mark. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel