From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f48.google.com (mail-pa0-f48.google.com [209.85.220.48]) by kanga.kvack.org (Postfix) with ESMTP id DCF146B0026 for ; Tue, 22 Dec 2015 09:57:58 -0500 (EST) Received: by mail-pa0-f48.google.com with SMTP id q3so97773771pav.3 for ; Tue, 22 Dec 2015 06:57:58 -0800 (PST) Received: from mga02.intel.com (mga02.intel.com. [134.134.136.20]) by mx.google.com with ESMTP id m74si25283737pfi.92.2015.12.22.06.57.57 for ; Tue, 22 Dec 2015 06:57:57 -0800 (PST) Subject: Re: [kernel-hardening] [RFC][PATCH 6/7] mm: Add Kconfig option for slab sanitization References: <1450755641-7856-1-git-send-email-laura@labbott.name> <1450755641-7856-7-git-send-email-laura@labbott.name> From: Dave Hansen Message-ID: <567964F3.2020402@intel.com> Date: Tue, 22 Dec 2015 06:57:55 -0800 MIME-Version: 1.0 In-Reply-To: <1450755641-7856-7-git-send-email-laura@labbott.name> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: kernel-hardening@lists.openwall.com, Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton Cc: Laura Abbott , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Kees Cook On 12/21/2015 07:40 PM, Laura Abbott wrote: > + The tradeoff is performance impact. The noticible impact can vary > + and you are advised to test this feature on your expected workload > + before deploying it What if instead of writing SLAB_MEMORY_SANITIZE_VALUE, we wrote 0's? That still destroys the information, but it has the positive effect of allowing a kzalloc() call to avoid zeroing the slab object. It might mitigate some of the performance impact. If this is on at compile time, but booted with sanitize_slab=off, is there a performance impact? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org