From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alan Cox Subject: Re: [PATCH 2/2] Perform check in iov_iter_fault_in_readable() by check_readable_bytes() Date: Mon, 18 May 2009 09:31:36 +0100 Message-ID: <20090518093136.152a1bb7@lxorguk.ukuu.org.uk> References: <1242317939-15392-1-git-send-email-v.mayatskih@gmail.com> <1242317939-15392-3-git-send-email-v.mayatskih@gmail.com> <87k54iq2gv.fsf@basil.nowhere.org> <871vqqkdf0.wl%vmayatsk@redhat.com> <20090515093838.GB16682@one.firstfloor.org> <20090515134315.GB8235@shareable.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: Andi Kleen , Vitaly Mayatskikh , Josef Bacik , sandeen@redhat.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org To: Jamie Lokier Return-path: Received: from earthlight.etchedpixels.co.uk ([81.2.110.250]:55165 "EHLO www.etchedpixels.co.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751962AbZERIax (ORCPT ); Mon, 18 May 2009 04:30:53 -0400 In-Reply-To: <20090515134315.GB8235@shareable.org> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: > System calls don't trigger SIGSEGVs so they can't rely on that when > calling read(). I'm not sure how they handle that. Usually by touching the pages before the syscall. (You can't rely on -EFAULT either in POSIX, its optional that it bothers to tell you and for example on MMUless it may well not)