From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AG47ELunzyjFUAWddkZ+sXUCWVRmDZPpWEep+o0i9IfwqMEYJjBa7H4jxbQB2La+SWHN6/0LRYVX ARC-Seal: i=1; a=rsa-sha256; t=1520285752; cv=none; d=google.com; s=arc-20160816; b=eDwZ5A3qD1623Wsuvxz+NqVizbq51vlm7zINJYuiratgrslN1zPy3jZ+2kUvNdTJAF 1SsLQQLKIHLlDocgKF9QYHVNUMLyjLqdrNr9CRBkHaVMPCupKT6me9x8ULJ43RLoNIGs S/wchzgKW8phMxktcdQb7d7c7JFlmY9ppb/tHFByS26wtldRKS6PNryXKRFvKZO5OuNT MipDmvGEeBPhsATSD9XKntO3cZvjvDi/V/9A6laqKZlYyyJIZWV4iuvDvfRr5OQKntQe o8jnD1mD+4+rsW0/eJ3UKOcDka6s3TTklyKurb0iWsjzAh7EcL07ukXWp80RKPNGSYxT JY7g== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=user-agent:in-reply-to:content-disposition:mime-version:references :message-id:subject:cc:to:from:date:dkim-signature :arc-authentication-results; bh=YkG5o87QVFAv4DcoNh0ORrjGhd/zFyVM+rEWX6BE5v8=; b=TKh3f7OKpFk7ghBfAlLu5r/gqJtaL7IlnnC12D/M6NYY4NaAAPNWXzixV7vZtyK4H/ 8bDmUZrZK4DVHy/Eg98/jCuBz+qGRFBhAanjwf/vcr6tA0jIXYAP0Hy88m0s3JyV+xNL TL9hvb7M3VHOX/pLwKeGQ3Aa640Bk3q9yCMWxD7+lz+ldMEApu/kwMxDrpbng4eUxMjb gO1ml6+NjejZSdUb5ueFp3PHWeWePrYu6xYE2jW2mxhV9rTu2eHU+XCfDZHlp0xalUm7 JFWOaRGfgWNUQD/edxmY8mnGXJbAwi9/VljCbwRqGlpxEuXlxgzXYXy7WjfWKZL9e9Uz 78kA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass (test mode) header.i=@8bytes.org header.s=mail-1 header.b=AXamb/K9; spf=pass (google.com: domain of joro@8bytes.org designates 2a01:238:4383:600:38bc:a715:4b6d:a889 as permitted sender) smtp.mailfrom=joro@8bytes.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=8bytes.org Authentication-Results: mx.google.com; dkim=pass (test mode) header.i=@8bytes.org header.s=mail-1 header.b=AXamb/K9; spf=pass (google.com: domain of joro@8bytes.org designates 2a01:238:4383:600:38bc:a715:4b6d:a889 as permitted sender) smtp.mailfrom=joro@8bytes.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=8bytes.org Date: Mon, 5 Mar 2018 22:35:50 +0100 From: Joerg Roedel To: Linus Torvalds Cc: Brian Gerst , Thomas Gleixner , Ingo Molnar , Peter Anvin , the arch/x86 maintainers , Linux Kernel Mailing List , linux-mm , Andrew Lutomirski , Dave Hansen , Josh Poimboeuf , =?iso-8859-1?Q?J=FCrgen_Gro=DF?= , Peter Zijlstra , Borislav Petkov , Jiri Kosina , Boris Ostrovsky , David Laight , Denys Vlasenko , Eduardo Valentin , Greg Kroah-Hartman , Will Deacon , "Liguori, Anthony" , Daniel Gruss , Hugh Dickins , Kees Cook , Andrea Arcangeli , Waiman Long , Pavel Machek , Joerg Roedel Subject: Re: [PATCH 07/34] x86/entry/32: Restore segments before int registers Message-ID: <20180305213550.GV16484@8bytes.org> References: <1520245563-8444-1-git-send-email-joro@8bytes.org> <1520245563-8444-8-git-send-email-joro@8bytes.org> <20180305131231.GR16484@8bytes.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1594093021030252223?= X-GMAIL-MSGID: =?utf-8?q?1594135152408786415?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On Mon, Mar 05, 2018 at 12:50:33PM -0800, Linus Torvalds wrote: > On Mon, Mar 5, 2018 at 12:38 PM, Brian Gerst wrote: > > > > There already is a test: single_step_syscall.c > > Ahh, good. So presumably Joerg actually did check it, just didn't even notice ;) Yeah, sort of. I ran the test, but it didn't catch the failure case in previous versions which was return to user with kernel-cr3 :) I could probably add some debug instrumentation to check for that in my future testing, as there is no NX protection in the user address-range for the kernel-cr3. Joerg