From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753467Ab3KOO0c (ORCPT ); Fri, 15 Nov 2013 09:26:32 -0500 Received: from mail-ea0-f178.google.com ([209.85.215.178]:39846 "EHLO mail-ea0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752138Ab3KOO0Z (ORCPT ); Fri, 15 Nov 2013 09:26:25 -0500 From: Peter Wu To: Al Viro , linux-kernel@vger.kernel.org Subject: [REGRESSION] coredumps truncated after "new helper: dump_align()" Date: Fri, 15 Nov 2013 15:26:10 +0100 Message-ID: <11835033.kIc1RH0rS1@al> User-Agent: KMail/4.11.3 (Linux/3.12.0-1-custom; KDE/4.11.3; x86_64; ; ) MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Al, Somewhere in the merge window of 3.13, coredumps appear truncated. Instead of 319488 bytes, I get 868 bytes (tested with x86_64 only). The latest Linus' master (v3.12-9579-g049ffa8) is still affected. Bisection leads to: commit 22a8cb8248ba5d340307ba72432253b1dbdb5cf7 Author: Al Viro Date: Tue Oct 8 11:05:01 2013 -0400 new helper: dump_align() dump_skip to given alignment... Signed-off-by: Al Viro :040000 040000 880920de653955485453c8cc11045bb09e2934f7 f8b348d32b59ae7a16cbc3eb2a6319f4df0210eb M arch :040000 040000 eaeffe2378806e95d23b3f3a9dc0fa8f078d6052 88866abde93296a05b4adda869280bc05403936f M fs :040000 040000 218263e01dd7473998c54a5a68ed5ae072854d24 ff531dce919862b662fef19a9a049f0de3db38ce M include I first noticed this bug on my laptop (v3.12-7033-g42a2d92) and reproduced this bug in a QEMU virtual machine too. If you want, I can also provide the git bisect script that starts QEMU and tests the serial output. That allows a kernel to be verified in two seconds (minus build times). Regards, Peter