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=-3.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,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 91788C2D0A3 for ; Wed, 4 Nov 2020 00:33:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4DA9D22403 for ; Wed, 4 Nov 2020 00:33:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604449986; bh=PJ+R6XPlsYAvbfPPVfH/b36l9Qxf3mjjxVF2HSd4mPY=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=aneGsiF8U47firFHfe53pBU/jZWZBZ12K5R3/u96tN7tcqg+W1nQuskGjPNOMl6Wn Lr2HUzCEsk+66IK6cIHAs/11mpweUcCozrdhxt2MhZsMQNkxOzGar3cZeiwa1aIMnP 2oOm1xzo6u9nNzRskgLOnjD5fkQDmS1fFizZvFu8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730022AbgKDAbY (ORCPT ); Tue, 3 Nov 2020 19:31:24 -0500 Received: from mail.kernel.org ([198.145.29.99]:47680 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729890AbgKDAbJ (ORCPT ); Tue, 3 Nov 2020 19:31:09 -0500 Received: from X1 (unknown [208.106.6.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 42824223EA; Wed, 4 Nov 2020 00:31:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604449867; bh=PJ+R6XPlsYAvbfPPVfH/b36l9Qxf3mjjxVF2HSd4mPY=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=ER7zLL0fsJywguzjfs3PdQZTmOgVAwtAz5yE5+b1SdacnLAOa3OQtAGteR5rW7qCD Ywc7Z9rUQo9Vi+5FVv3vDhZ6WcR6fNJM16p3Tc2cdLZyMHI3nO70s8Q5UgVBzUwL0U RpnJUxRfACjNdutK4tXoVqBpsWdb3+kUMVEy2qI4= Date: Tue, 3 Nov 2020 16:31:03 -0800 From: Andrew Morton To: Marco Elver Cc: glider@google.com, hpa@zytor.com, paulmck@kernel.org, andreyknvl@google.com, aryabinin@virtuozzo.com, luto@kernel.org, bp@alien8.de, catalin.marinas@arm.com, cl@linux.com, dave.hansen@linux.intel.com, rientjes@google.com, dvyukov@google.com, edumazet@google.com, gregkh@linuxfoundation.org, hdanton@sina.com, mingo@redhat.com, jannh@google.com, Jonathan.Cameron@huawei.com, corbet@lwn.net, iamjoonsoo.kim@lge.com, joern@purestorage.com, keescook@chromium.org, mark.rutland@arm.com, penberg@kernel.org, peterz@infradead.org, sjpark@amazon.com, tglx@linutronix.de, vbabka@suse.cz, will@kernel.org, x86@kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org Subject: Re: [PATCH v7 0/9] KFENCE: A low-overhead sampling-based memory safety error detector Message-Id: <20201103163103.109deb9d49a140032d67434f@linux-foundation.org> In-Reply-To: <20201103175841.3495947-1-elver@google.com> References: <20201103175841.3495947-1-elver@google.com> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.32; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 3 Nov 2020 18:58:32 +0100 Marco Elver wrote: > This adds the Kernel Electric-Fence (KFENCE) infrastructure. KFENCE is a > low-overhead sampling-based memory safety error detector of heap > use-after-free, invalid-free, and out-of-bounds access errors. This > series enables KFENCE for the x86 and arm64 architectures, and adds > KFENCE hooks to the SLAB and SLUB allocators. > > KFENCE is designed to be enabled in production kernels, and has near > zero performance overhead. Compared to KASAN, KFENCE trades performance > for precision. The main motivation behind KFENCE's design, is that with > enough total uptime KFENCE will detect bugs in code paths not typically > exercised by non-production test workloads. One way to quickly achieve a > large enough total uptime is when the tool is deployed across a large > fleet of machines. Has kfence detected any kernel bugs yet? What is its track record? Will a kfence merge permit us to remove some other memory debugging subsystem? We seem to have rather a lot of them.