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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 2474FC43381 for ; Thu, 7 Mar 2019 20:40:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ECE6420675 for ; Thu, 7 Mar 2019 20:40:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726275AbfCGUkX (ORCPT ); Thu, 7 Mar 2019 15:40:23 -0500 Received: from relay.sw.ru ([185.231.240.75]:58482 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726166AbfCGUkW (ORCPT ); Thu, 7 Mar 2019 15:40:22 -0500 Received: from [192.168.15.238] by relay.sw.ru with esmtp (Exim 4.91) (envelope-from ) id 1h1zoO-0003gj-Ee; Thu, 07 Mar 2019 23:40:16 +0300 Subject: Re: [PATCH 18/20] objtool: Add UACCESS validation To: Peter Zijlstra Cc: Linus Torvalds , Thomas Gleixner , Peter Anvin , Julien Thierry , Will Deacon , Andy Lutomirski , Ingo Molnar , Catalin Marinas , James Morse , valentin.schneider@arm.com, Brian Gerst , Josh Poimboeuf , Andrew Lutomirski , Borislav Petkov , Denys Vlasenko , Linux List Kernel Mailing , Dmitry Vyukov , Steven Rostedt References: <20190307114511.870090179@infradead.org> <20190307115200.697533978@infradead.org> <20190307174135.GJ32477@hirez.programming.kicks-ass.net> <6a4875bd-2b22-91e4-cbe2-b01c12786a1b@virtuozzo.com> <20190307203318.GM32477@hirez.programming.kicks-ass.net> From: Andrey Ryabinin Message-ID: Date: Thu, 7 Mar 2019 23:40:06 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.5.2 MIME-Version: 1.0 In-Reply-To: <20190307203318.GM32477@hirez.programming.kicks-ass.net> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 3/7/19 11:33 PM, Peter Zijlstra wrote: > On Thu, Mar 07, 2019 at 11:15:42PM +0300, Andrey Ryabinin wrote: >> >> >> On 3/7/19 8:41 PM, Peter Zijlstra wrote: >>> On Thu, Mar 07, 2019 at 08:33:26AM -0800, Linus Torvalds wrote: >>>> On Thu, Mar 7, 2019 at 3:52 AM Peter Zijlstra wrote: >>>>> >>>>> XXX: are we sure we want __memset marked AC-safe? >>>> >>>> It's certainly one of the safer functions to call with AC set, but it >>>> sounds wrong anyway. It's not like it's likely to leak kernel data >>>> (most memset's are with 0, and even the non-zero ones I can't imagine >>>> are sensitive - more like poison values etc). >>>> >>>> What's the call site that made you go "just add __memset() to the list"? >>> >>> __asan_{,un}poinson_stack_memory() >> >> These two can be called only with CONFIG_KASAN_EXTRA=y which >> was removed very recently, so it should be safe to delete these functions. > > Ooh shiny. Clearly my tree still has them; what commit do I need to look > for? > commit 7771bdbbfd3d6f204631b6fd9e1bbc30cd15918e