From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 04BC1C2BA19 for ; Mon, 6 Apr 2020 13:02:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D230F22262 for ; Mon, 6 Apr 2020 13:02:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728299AbgDFNCz (ORCPT ); Mon, 6 Apr 2020 09:02:55 -0400 Received: from zeniv.linux.org.uk ([195.92.253.2]:53142 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728154AbgDFNCz (ORCPT ); Mon, 6 Apr 2020 09:02:55 -0400 Received: from viro by ZenIV.linux.org.uk with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jLROg-00CA1y-Gz; Mon, 06 Apr 2020 13:02:38 +0000 Date: Mon, 6 Apr 2020 14:02:38 +0100 From: Al Viro To: Christoph Hellwig Cc: Andrew Morton , Jeremy Kerr , Arnd Bergmann , linuxppc-dev@lists.ozlabs.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 3/6] binfmt_elf: remove the set_fs(KERNEL_DS) in elf_core_dump Message-ID: <20200406130238.GT23230@ZenIV.linux.org.uk> References: <20200406120312.1150405-1-hch@lst.de> <20200406120312.1150405-4-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200406120312.1150405-4-hch@lst.de> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Apr 06, 2020 at 02:03:09PM +0200, Christoph Hellwig wrote: > There is no logic in elf_core_dump itself that uses uaccess routines > on kernel pointers, the file writes are nicely encapsulated in dump_emit > which does its own set_fs. ... assuming you've checked the asm/elf.h to see that nobody is playing silly buggers in these forests of macros and the stuff called from those. Which is a feat that ought to be mentioned in commit message...