Received: by 2002:a05:6a10:22f:0:0:0:0 with SMTP id 15csp3288266pxk; Tue, 15 Sep 2020 15:27:53 -0700 (PDT) X-Google-Smtp-Source: ABdhPJx63+2vMJpLZbwLIf0I9G6ykKZw43W6w7xpkJZwQ2AQQtIDhaR+MizEEL/cl+ivDYAmQYt2 X-Received: by 2002:aa7:d6c4:: with SMTP id x4mr24208788edr.98.1600208872946; Tue, 15 Sep 2020 15:27:52 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1600208872; cv=none; d=google.com; s=arc-20160816; b=OgYa0eEcoaN1aDrcRMySC8cFfKxTlXHuKgpTfv5/nZFFGfuVFGO1My2mMqHkXW6N5j E0ZBOJIC4e96U4/5AgV6Hi55DCpswpRLsk+rwqNEXUJYlGa9/JFPqN4KwqTELhb+a+dl gc4ZYQw8iu+X9lSA/Crv36Z8HR5a9ou2rIdcOmaKNNgE4xU04FgOYd6g/f8Usd7TY2iF MNd0VEk/Vomazw27kaS9P14+o0zyco+yOQEuYK41pA/Wu032k4j3l9Csx2QYiJMHge5J STT/W2PzPmqPDHJiZlZx6UIh95UFEjTlez3O1AATydMfCEJN06cUYbprySV9zNJWCabY 1/4A== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:in-reply-to:content-disposition :mime-version:references:message-id:subject:cc:to:from:date; bh=PaY2r+7/muyhAuHYWYFHiIsedBSbp2PRs96RxJ3uSms=; b=jJpa75ZQBEGfjmZRIKmqtfFS+NXL0vJ9qYvhBoJ+uGjmaw3/dS0fdqiWqIwvfm+RB+ KZwZ0RvL9P89RfM2OeP3diAmK5APwDATMETlpuiJcFqkgmWiM8iKbldLqA4jbbncqFyf 8NYvuNL0HC1fHa+uxVOHJv0PajTmqXPxPd2UnvRz8KOqxP7L1PMu6oPNmjE+THpMiiCY pj4oZmgzOkx9iz9xbAA1QeAPkBzM481P+PfBVSEl4ka+gfL5x8F5zfGWH3rDh4FGhJ8T RhM/BeQ/Ohuu1zGAY8sDRypQfbBPFSPBfz6hlJG/48GZv2r4px4BCDDVnc3PsXmRQLEj AaHA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id n25si10563423edt.464.2020.09.15.15.27.30; Tue, 15 Sep 2020 15:27:52 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727547AbgIOW0v (ORCPT + 99 others); Tue, 15 Sep 2020 18:26:51 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:49509 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727643AbgIOQV2 (ORCPT ); Tue, 15 Sep 2020 12:21:28 -0400 Received: from ip5f5af089.dynamic.kabel-deutschland.de ([95.90.240.137] helo=wittgenstein) by youngberry.canonical.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1kIDVY-0006rA-V3; Tue, 15 Sep 2020 16:08:41 +0000 Date: Tue, 15 Sep 2020 18:08:40 +0200 From: Christian Brauner To: Kees Cook Cc: linux-kernel@vger.kernel.org, Thadeu Lima de Souza Cascardo , Max Filippov , Michael Ellerman , Christian Brauner , Andy Lutomirski , Will Drewry , linux-kselftest@vger.kernel.org, linux-mips@vger.kernel.org, linux-xtensa@linux-xtensa.org, linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH 10/15] selftests/seccomp: Avoid redundant register flushes Message-ID: <20200915160840.6ybm67gowqeqyms2@wittgenstein> References: <20200912110820.597135-1-keescook@chromium.org> <20200912110820.597135-11-keescook@chromium.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20200912110820.597135-11-keescook@chromium.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Sep 12, 2020 at 04:08:15AM -0700, Kees Cook wrote: > When none of the registers have changed, don't flush them back. This can > happen if the architecture uses a non-register way to change the syscall > (e.g. arm64) , and a return value hasn't been written. > > Signed-off-by: Kees Cook > --- Looks good! Acked-by: Christian Brauner