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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 1D5B8C433F5 for ; Tue, 8 Mar 2022 18:41:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc: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=BI1Yja03S5t4p1pEY/7on1MFQgNxpByjc+RUXlVHtM8=; b=WiO92F9vDa+2YH 694vnUZxSxf1Z4H0W5bOJMIgZmnbYQ+iprpUgRz+65cZDmvf/OL6ilfR+YYyygA2Vb4zJx9keI1ii Aa/P/wQjjpeUgWGmiwadRO3iVe3d7bgxb8CTl82VFd9qJ+VIRvruo4UMW5TfnB4Za0GWSsS7PTWSv 26FFzgEDxqDjciOHou9kvUccPEjhJYKxAxUfrARaalMP4yOWZuXzx9aoiTCxJ7+MVaHqTyhsCk+iA 81MwDYpRQcVFzjIptMcARRhy8vidH1qBYn3H/85pbHf4bQqABBoQ2fsV48XgnI6CH5OnYgVMlsjxo EKzHnEYc+S2ofU8C2f6w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nRel1-005o2g-LW; Tue, 08 Mar 2022 18:40:27 +0000 Received: from ams.source.kernel.org ([2604:1380:4601:e00::1]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nReky-005o28-NP for linux-arm-kernel@lists.infradead.org; Tue, 08 Mar 2022 18:40:26 +0000 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 63D6BB81C6D; Tue, 8 Mar 2022 18:40:23 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A5309C340F5; Tue, 8 Mar 2022 18:40:20 +0000 (UTC) Date: Tue, 8 Mar 2022 18:40:17 +0000 From: Catalin Marinas To: Mark Brown Cc: Will Deacon , linux-arm-kernel@lists.infradead.org, Evgenii Stepanov , Peter Collingbourne , Joey Gouly , Branislav Rankov Subject: Re: [PATCH] arm64/mte: Remove asymmetric mode from the prctl() interface Message-ID: References: <20220308142230.3138843-1-broonie@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20220308142230.3138843-1-broonie@kernel.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220308_104024_928692_29C1A5CA X-CRM114-Status: GOOD ( 13.10 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, Mar 08, 2022 at 02:22:30PM +0000, Mark Brown wrote: > diff --git a/arch/arm64/kernel/mte.c b/arch/arm64/kernel/mte.c > index fb777d8fea32..2b35b706a7ba 100644 > --- a/arch/arm64/kernel/mte.c > +++ b/arch/arm64/kernel/mte.c > @@ -308,7 +308,16 @@ long set_mte_ctrl(struct task_struct *task, unsigned long arg) > mte_ctrl |= MTE_CTRL_TCF_ASYNC; > if (arg & PR_MTE_TCF_SYNC) > mte_ctrl |= MTE_CTRL_TCF_SYNC; > - if (arg & PR_MTE_TCF_ASYMM) > + > + /* > + * If the system supports it and both sync and async modes are > + * specified then implicitly enable asymmetric mode. > + * Userspace could see a mix of both sync and async anyway due > + * to differing or changing defaults on CPUs. > + */ Exactly, so it can't be confusing for an application. Reviewed-by: Catalin Marinas _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel