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=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 2ACD3C43381 for ; Thu, 7 Mar 2019 18:01:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0132E20851 for ; Thu, 7 Mar 2019 18:01:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1551981693; bh=O+bRqHthnwvyPcuC0Q+KKKGemMBCFF9fEIk1FchSqbI=; h=References:In-Reply-To:From:Date:Subject:To:Cc:List-ID:From; b=tUKfBUg7vK+mLEzRAxku5VJyC+vHVtvKLdki73jhOKXhDZhP+j8FNMHT1BH6ZIBKu nLGyeIhFB7esAQFHWJYsMkmjyFylFvdzUIgfwEWfk/QG6CmVBni2rZhoULRqtFGG7a P0SSFn/heuUuCmweRqdO7hMopw5wPkleA5NSC0IQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726689AbfCGSBb (ORCPT ); Thu, 7 Mar 2019 13:01:31 -0500 Received: from mail-lj1-f195.google.com ([209.85.208.195]:42304 "EHLO mail-lj1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726166AbfCGSBb (ORCPT ); Thu, 7 Mar 2019 13:01:31 -0500 Received: by mail-lj1-f195.google.com with SMTP id d14so15062999ljl.9 for ; Thu, 07 Mar 2019 10:01:29 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=36kE0MkjNErUKnrp0BPqSQ3I9YheVL32EsxlaB1Zqaw=; b=FhHNRP++Rj3t91SJAsxCUhLZm4eFqEeYml1UPR53Ma/g+zafmKyQmDN65Ti9LF/3Qy TSxxWQ4K/u6Wt94HMWR6D9o12999pFmVRMwXgVNmJ998JblJrwL4nUhrBgwNQ6pFzFuS DwgwVWKQWA7y4n9Y2fF8yvWvafIW3g9otyucA= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=36kE0MkjNErUKnrp0BPqSQ3I9YheVL32EsxlaB1Zqaw=; b=LCOoWUb7/BLNyb03Noxndnh+u0exA7iAqnGcDDV7kDMFVDlm/lqvVm91izfEP7RQFH 3su6lQ2YVu8u33OygUpbXvR+otim+dw4hcvQuxMBfFuuL3a1HdwOmvu3nUWgKJaB9wc6 Eeh+xySNWP8XffCEELovXFJweTj/Zob3AxvVntKJNztc7ThCYcHlfWSHgMjsrekl7cgC 3U2dIV2/tsBtzIKlJMZq+JfAhBf5o2FBawO8KXLUzQyD5gs4nbw/w0XuWcYzrFq5Wbjc 9pvvO++jMFxItF7ARw9KSHR3yUtvyFheg98pJN3173zOn/xdmS5Sw7Iro5uQbEa1z6mn kgfw== X-Gm-Message-State: APjAAAU2v3navmjJ5opFNdVHV6XQbhcXM+6jUoqj9iDjwAnWKSL7kBVw GTs4FZRvtS2+JfHSLCf5zkIV2ECy+74= X-Google-Smtp-Source: APXvYqwtsRO/h51dyTPiEPu1jH6+p7wzX6v5dlu6NEVp4fpCl61eB56HC467P0aQ5OytsVVp0T8a9A== X-Received: by 2002:a2e:9607:: with SMTP id v7mr6720271ljh.154.1551981688503; Thu, 07 Mar 2019 10:01:28 -0800 (PST) Received: from mail-lj1-f176.google.com (mail-lj1-f176.google.com. [209.85.208.176]) by smtp.gmail.com with ESMTPSA id s73sm515055lfe.3.2019.03.07.10.01.28 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 07 Mar 2019 10:01:28 -0800 (PST) Received: by mail-lj1-f176.google.com with SMTP id z25so15070447ljk.8 for ; Thu, 07 Mar 2019 10:01:28 -0800 (PST) X-Received: by 2002:a2e:208a:: with SMTP id g10mr6579542lji.135.1551981269940; Thu, 07 Mar 2019 09:54:29 -0800 (PST) MIME-Version: 1.0 References: <20190307114511.870090179@infradead.org> <20190307115200.697533978@infradead.org> <20190307174135.GJ32477@hirez.programming.kicks-ass.net> In-Reply-To: <20190307174135.GJ32477@hirez.programming.kicks-ass.net> From: Linus Torvalds Date: Thu, 7 Mar 2019 09:54:14 -0800 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH 18/20] objtool: Add UACCESS validation To: Peter Zijlstra Cc: 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 Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. Again, maybe we could avoid the static checking entirely for the complex configs, and just make preempt_schedule() not do it for AC regions. Because AC vs KASAN in general ends up smelling like "not a fight worth fighting" to me. You've done a herculean job, but.. Linus