From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755945AbaEOVb2 (ORCPT ); Thu, 15 May 2014 17:31:28 -0400 Received: from mail-lb0-f171.google.com ([209.85.217.171]:51885 "EHLO mail-lb0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753704AbaEOVb1 (ORCPT ); Thu, 15 May 2014 17:31:27 -0400 Date: Fri, 16 May 2014 01:31:24 +0400 From: Cyrill Gorcunov To: Andy Lutomirski Cc: Andrew Morton , Sasha Levin , "linux-mm@kvack.org" , Dave Jones , LKML , Pavel Emelyanov Subject: Re: mm: NULL ptr deref handling mmaping of special mappings Message-ID: <20140515213124.GT28328@moon> References: <5373DBE4.6030907@oracle.com> <20140514143124.52c598a2ba8e2539ee76558c@linux-foundation.org> <20140514221140.GF28328@moon> <20140515084558.GI28328@moon> <20140515195320.GR28328@moon> <20140515201914.GS28328@moon> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140515201914.GS28328@moon> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 16, 2014 at 12:19:14AM +0400, Cyrill Gorcunov wrote: > > I see what you mean. We're rather targeting on bare x86-64 at the moment > but compat mode is needed as well (not yet implemented though). I'll take > a precise look into this area. Thanks! Indeed, because we were not running 32bit tasks vdso32-setup.c::arch_setup_additional_pages has never been called. That's the mode we will have to implement one day. Looking forward the question appear -- will VDSO_PREV_PAGES and rest of variables be kind of immutable constants? If yes, we could calculate where the additional vma lives without requiring any kind of [vdso] mark in proc/pid/maps output.