From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932138AbbDPSPA (ORCPT ); Thu, 16 Apr 2015 14:15:00 -0400 Received: from mx1.redhat.com ([209.132.183.28]:39857 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751723AbbDPSOv (ORCPT ); Thu, 16 Apr 2015 14:14:51 -0400 Message-ID: <552FFC19.8030007@redhat.com> Date: Thu, 16 Apr 2015 14:14:49 -0400 From: Rik van Riel User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.3.0 MIME-Version: 1.0 To: Borislav Petkov , Ingo Molnar CC: LKML , Oleg Nesterov , Andy Lutomirski , "H. Peter Anvin" , Linus Torvalds , Tavis Ormandy , Thomas Gleixner Subject: Re: [PATCH] x86/fpu: Load xsave pointer *after* initialization References: <1429207509-1717-1-git-send-email-bp@alien8.de> In-Reply-To: <1429207509-1717-1-git-send-email-bp@alien8.de> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/16/2015 02:05 PM, Borislav Petkov wrote: > From: Borislav Petkov > > So I was playing with gdb today and did this simple thing: > > gdb /bin/ls > > ... > > (gdb) run > > Box exploded with the splat at the end because we do cache > &target->thread.fpu.state->xsave into the local variable xsave but > that pointer is NULL at that time and it gets initialized later, in > init_fpu(), see > Signed-off-by: Borislav Petkov > Cc: Oleg Nesterov > Cc: Rik van Riel > Cc: Andy Lutomirski > Cc: H. Peter Anvin > Cc: Linus Torvalds > Cc: Tavis Ormandy > Cc: Thomas Gleixner Reviewed-by: Rik van Riel