From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753162AbaDMDIN (ORCPT ); Sat, 12 Apr 2014 23:08:13 -0400 Received: from lennier.cc.vt.edu ([198.82.162.213]:37071 "EHLO lennier.cc.vt.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751158AbaDMDIL (ORCPT ); Sat, 12 Apr 2014 23:08:11 -0400 X-Mailer: exmh version 2.8.0 04/21/2012 with nmh-1.5+dev To: Alexander.Kleinsorge@gmx.de Cc: linux-kernel@vger.kernel.org Subject: Re: new module to check constant memory for corruption In-Reply-To: Your message of "Sun, 13 Apr 2014 03:33:10 +0200." From: Valdis.Kletnieks@vt.edu References: Mime-Version: 1.0 Content-Type: multipart/signed; boundary="==_Exmh_1397358483_25296P"; micalg=pgp-sha1; protocol="application/pgp-signature" Content-Transfer-Encoding: 7bit Date: Sat, 12 Apr 2014 23:08:03 -0400 Message-ID: <36478.1397358483@turing-police.cc.vt.edu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --==_Exmh_1397358483_25296P Content-Type: text/plain; charset=us-ascii On Sun, 13 Apr 2014 03:33:10 +0200, Alexander.Kleinsorge@gmx.de said: > printk(KERN_EMERG MODNAME "error: const kernel memory is broken (%08lx != 0), please reboot!", g_SumLast); Make a list of all the things that can dynamically modify kernel text while it's running, starting with the alternatives code, and adding in the various tracing and debugging tools, and ask yourself if KERN_EMERG is the right choice here... Also, that printk is in the wrong place - it only fires if somebody reads the /proc file, and it *should* trigger as soon as practical after a problem has been detected. Bonus points for computing what percent of single, double, triple, and other error syndromes your xor detects (hint - what is the behavior of a dead row or column of bits?). --==_Exmh_1397358483_25296P Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 Comment: Exmh version 2.5 07/13/2001 iQIVAwUBU0n/kwdmEQWDXROgAQJ7EQ//Rahr6YNor1K8raauU3OFUx142qIaeax8 dy4yZefQaLIfg8vW4fUlrux/tHeWEMOEW3xBlVHOOaL9V9rE2Gvsy2U6Jolht6XB o0A3QKE8XnMIJMTnPg9eClOObT+XZdauzDJgAOfdFmTCE/TN/dAuVBezA3jxBfU+ uqbC9F1qu3ozyVtYWfQjk4fo/CiveOFJ+KK+tRUia7IuEAdLeU9ns8aA9c9pjudZ rwomJzuNd6cwKIzQ3qZFI93Kfqb5Iy1+xUsoqU3azow0YRL5nCvF49sB8eSW/xc6 YQWt5Qn1udu9id3UqWjq669SmNOxegDZBySL8ffsjaC5WlIMhTJxtMWZb2SqPOqE yQJ2bknJrwGLAmOtgkcDhZ+Y6+KI8ItrHf36ssTlF93eOk4NTmX/DHmcH37ziTpX ZxNqh+Jku95yAPGy43ZGCkqADWreYmTDcV+jSl30cE7lj1civsuLvmeOPnJmLl3t V1LATb+TyBBkVqelRrr38GlizhrvBGDhK5E35vFFuC7/P2ZYIvE3X0X+0lS7bO/T Mvffi/qU+rGPEby8K19rslAJGKZP4hSmU2++/WDCNiB61E4h/gajFuFeYyU3SHAF ZqlShwzz+AiM6LkZMULgDK6omGn+oB6CFJWyzk2Oo6CF1UUkzW5VpJHOvryYBwoA /eKAcWuCBWw= =oJKe -----END PGP SIGNATURE----- --==_Exmh_1397358483_25296P--