From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751685AbaFBTYz (ORCPT ); Mon, 2 Jun 2014 15:24:55 -0400 Received: from mx1.redhat.com ([209.132.183.28]:17269 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750750AbaFBTYy (ORCPT ); Mon, 2 Jun 2014 15:24:54 -0400 Date: Mon, 2 Jun 2014 21:23:44 +0200 From: Oleg Nesterov To: Christoph Hellwig Cc: Ingo Molnar , Denys Vlasenko , Hugh Dickins , Jim Keniston , Masami Hiramatsu , Srikar Dronamraju , linux-kernel@vger.kernel.org Subject: Re: [GIT PULL] uprobes: tmpfs support Message-ID: <20140602192344.GA30792@redhat.com> References: <20140602141406.GA17863@redhat.com> <20140602183028.GA9372@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140602183028.GA9372@infradead.org> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/02, Christoph Hellwig wrote: > > On Mon, Jun 02, 2014 at 04:14:06PM +0200, Oleg Nesterov wrote: > > Ingo, please pull from > > > > git://git.kernel.org/pub/scm/linux/kernel/git/oleg/misc uprobes/core > > > > Based on tip:perf/uprobes > > Eww, adding tmpfs-specific code to uprobes screams layering violation. > > Hugh, what is the problem with implementing ->readpage for tmpfs again? I leave this to you and Hugh. But I hope you are not arguing with this patch, it is very simple and we do want to support tmpfs. If tmpfs has ->readpage again we can revert this patch. BTW. Is it safe to pass file == NULL to read_mapping_page() and ->readpage()? Last time I tried to check this looked safe but this is not documented. We need to call read_mapping_page() from uprobe_register() but it doesn't have "struct file *" and thus we need to delay arch_uprobe_analyze_insn() until we find the first mapping, too bad. And why read_mapping_page() has "void *data" but not "struct file *file"... Oleg.