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 E8268C43381 for ; Thu, 7 Mar 2019 18:52:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B998720840 for ; Thu, 7 Mar 2019 18:52:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726596AbfCGSw4 convert rfc822-to-8bit (ORCPT ); Thu, 7 Mar 2019 13:52:56 -0500 Received: from terminus.zytor.com ([198.137.202.136]:34325 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726161AbfCGSw4 (ORCPT ); Thu, 7 Mar 2019 13:52:56 -0500 Received: from [IPv6:2607:fb90:3224:d3ed:dc53:8bcb:85c6:5b5b] ([IPv6:2607:fb90:3224:d3ed:dc53:8bcb:85c6:5b5b]) (authenticated bits=0) by mail.zytor.com (8.15.2/8.15.2) with ESMTPSA id x27Iq2dH2300868 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NO); Thu, 7 Mar 2019 10:52:03 -0800 Date: Thu, 07 Mar 2019 10:51:59 -0800 User-Agent: K-9 Mail for Android In-Reply-To: <20190307184813.GL32477@hirez.programming.kicks-ass.net> References: <20190307114511.870090179@infradead.org> <20190307115200.697533978@infradead.org> <20190307174135.GJ32477@hirez.programming.kicks-ass.net> <20190307184813.GL32477@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT Subject: Re: [PATCH 18/20] objtool: Add UACCESS validation To: Peter Zijlstra , Linus Torvalds CC: Thomas Gleixner , 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 From: hpa@zytor.com Message-ID: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On March 7, 2019 10:48:13 AM PST, Peter Zijlstra wrote: >On Thu, Mar 07, 2019 at 09:54:14AM -0800, Linus Torvalds wrote: >> On Thu, Mar 7, 2019 at 9:41 AM Peter Zijlstra >wrote: >> > > >> > > What's the call site that made you go "just add __memset() to the >list"? >> > >> > __asan_{,un}poinson_stack_memory() >> > kasan_{,un}poison_shadow() >> > __memset() >> >> Ugh. I think I almost just agree with your decision to just let that >> memset go unchecked. >> >> I'm not saying it's right, but it doesn't seem to be a fight worth >fighting. > >One think I could do; is add a filter to each function and only allow >__memset from the kasan code, and not from anywhere else. > >Another thing I need to look at is why objtool only found memset_orig >(from __memset) but not memset_erms, which if I read the code right, is >a possible alternative there. > >> Because AC vs KASAN in general ends up smelling like "not a fight >> worth fighting" to me. You've done a herculean job, but.. > >I know,.. I've been so close to doing that so many times, but it >seems like defeat, esp. since I'm so close now :-) ___memset_kasan()? -- Sent from my Android device with K-9 Mail. Please excuse my brevity.