From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752638AbYIVIkF (ORCPT ); Mon, 22 Sep 2008 04:40:05 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751877AbYIVIjz (ORCPT ); Mon, 22 Sep 2008 04:39:55 -0400 Received: from bombadil.infradead.org ([18.85.46.34]:58914 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751849AbYIVIjz (ORCPT ); Mon, 22 Sep 2008 04:39:55 -0400 Date: Mon, 22 Sep 2008 04:39:46 -0400 From: Christoph Hellwig To: Andrew Morton Cc: Krishna Kumar , linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm: do_generic_file_read() never gets a NULL 'filp' argument Message-ID: <20080922083945.GA12658@infradead.org> References: <20080922061610.20158.86022.sendpatchset@localhost.localdomain> <20080922013338.8e1c10ff.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080922013338.8e1c10ff.akpm@linux-foundation.org> User-Agent: Mutt/1.5.18 (2008-05-17) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Sep 22, 2008 at 01:33:38AM -0700, Andrew Morton wrote: > On Mon, 22 Sep 2008 11:46:10 +0530 Krishna Kumar wrote: > > > From: Krishna Kumar > > > > The 'filp' argument to do_generic_file_read() is never NULL. > > > > How did you verify this? > > NFS used to like passing NULL file*'s into VFS functions. I don't > recall whether it affected do_generic_file_read(). The only thing nfsd passed a NULL file pointer in is ->fsync on directories. If anyone did pass a NULL file pointer into do_generic_file_read it would oops in it's very first line of code.