From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753432AbaDMDAc (ORCPT ); Sat, 12 Apr 2014 23:00:32 -0400 Received: from mga01.intel.com ([192.55.52.88]:54099 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751359AbaDMDAb (ORCPT ); Sat, 12 Apr 2014 23:00:31 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.97,849,1389772800"; d="scan'208";a="512115199" From: Andi Kleen To: Alexander.Kleinsorge@gmx.de Cc: linux-kernel@vger.kernel.org Subject: Re: new module to check constant memory for corruption References: Date: Sat, 12 Apr 2014 20:00:30 -0700 In-Reply-To: (Alexander Kleinsorge's message of "Sun, 13 Apr 2014 03:33:10 +0200") Message-ID: <87eh12hr1t.fsf@tassilo.jf.intel.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Alexander.Kleinsorge@gmx.de writes: > ramcheck kernel module > new module to check constant memory for corruption > > detect corruption of constant kernel memory (text and data) periodically. > runtime costs about 1..2 ms per sec (about 10 mb with 5 mb/ms), > which is distributed over 8 (BLOCKS) time partitions (less than half > ms per sec). > in case of checksum (xor) error, an kernel log is posted. > manual trigger via /proc/ramcheck is possible. > range: kallsyms_lookup_name("_text") .. kallsyms_lookup_name("__end_rodata") Can you explain how this works? How does it handle legal writes? If it just checks its own memory it could be done in user space. -Andi -- ak@linux.intel.com -- Speaking for myself only