From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753126Ab2GIKcE (ORCPT ); Mon, 9 Jul 2012 06:32:04 -0400 Received: from e6.ny.us.ibm.com ([32.97.182.146]:59613 "EHLO e6.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752975Ab2GIKcB (ORCPT ); Mon, 9 Jul 2012 06:32:01 -0400 Date: Mon, 9 Jul 2012 16:00:35 +0530 From: Srikar Dronamraju To: Oleg Nesterov Cc: Ingo Molnar , Peter Zijlstra , Ananth N Mavinakayanahalli , Anton Arapov , Hugh Dickins , linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 1/5] uprobes: don't recheck vma/f_mapping in write_opcode() Message-ID: <20120709103032.GF32393@linux.vnet.ibm.com> Reply-To: Srikar Dronamraju References: <20120624145936.GA23269@redhat.com> <20120624150002.GA23277@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20120624150002.GA23277@redhat.com> User-Agent: Mutt/1.5.20 (2009-06-14) X-Content-Scanned: Fidelis XPS MAILER x-cbid: 12070910-1976-0000-0000-00000EFFAC9B Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Oleg Nesterov [2012-06-24 17:00:02]: > write_opcode() rechecks valid_vma() and ->f_mapping, this is pointless. > The caller, register_for_each_vma() or uprobe_mmap(), has already done > these checks under mmap_sem. > > To clarify, uprobe_mmap() checks valid_vma() only, but we can rely on > build_probe_list(vm_file->f_mapping->host). > > Signed-off-by: Oleg Nesterov Acked-by: Srikar Dronamraju