From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sog-mx-1.v43.ch3.sourceforge.com ([172.29.43.191] helo=mx.sourceforge.net) by sfs-ml-2.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1agxmX-00084I-I5 for user-mode-linux-devel@lists.sourceforge.net; Fri, 18 Mar 2016 17:01:49 +0000 Received: from u16576595.onlinehome-server.com ([74.208.238.6] helo=euler.addtoit.com) by sog-mx-1.v43.ch3.sourceforge.com with esmtp (Exim 4.76) id 1agxmW-0001pl-IV for user-mode-linux-devel@lists.sourceforge.net; Fri, 18 Mar 2016 17:01:49 +0000 Date: Fri, 18 Mar 2016 12:42:43 -0400 From: Jeff Dike Message-ID: <20160318164243.GA979@parts.user-mode-linux.org> References: <1458091505-967-1-git-send-email-elicooper@gmx.com> <56EB2DF8.8030102@nod.at> <56EB5CC9.1030601@gmx.com> <56EBBA61.4090405@nod.at> <56EC293B.8020407@gmx.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <56EC293B.8020407@gmx.com> Subject: Re: [uml-devel] [PATCH] um: fix FPU register double-restore after sigreturn List-Id: The user-mode Linux development list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: user-mode-linux-devel-bounces@lists.sourceforge.net To: Eli Cooper Cc: Richard Weinberger , user-mode-linux-devel@lists.sourceforge.net On Sat, Mar 19, 2016 at 12:13:47AM +0800, Eli Cooper wrote: > I agree that we should keep userspace() minimal. So what in the first > place is the FPU state save/restore code for? Or, what (except for > sigreturn) could possibly mess the FPU state of the ptrace'd process > without it? My (vague) recollection was that with libc in there, I couldn't be confident that it wouldn't unexpectedly use FP for something. So, saving and restoring FP state was a hedge against that happening. Jeff -- Jeff Dike AddToIt 978-254-0789 (o) 978-394-8986 (c) ------------------------------------------------------------------------------ Transform Data into Opportunity. Accelerate data analysis in your applications with Intel Data Analytics Acceleration Library. Click to learn more. http://pubads.g.doubleclick.net/gampad/clk?id=278785231&iu=/4140 _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel