Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752228Ab1BAHjF (ORCPT ); Tue, 1 Feb 2011 02:39:05 -0500 Received: from mail-vw0-f46.google.com ([209.85.212.46]:34069 "EHLO mail-vw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751450Ab1BAHjD (ORCPT ); Tue, 1 Feb 2011 02:39:03 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:content-transfer-encoding :in-reply-to:user-agent; b=fYcnDCs/Ch1JJCv35j5wm8Z7dsPHSkImA0GalGbQ9G3CUI+AV4rI5/D4v7V8JaXaUB s7gHt5irWM255W4gNgtzmvyNsz9P0b45T7Vt6FBp+LOBWAuWKcdCmKDU9eGCuEeMbjV/ HM1uGjhWOHFdXf+9B4Z5OOpD8O63FMOvd8Qxk= Date: Tue, 1 Feb 2011 15:38:53 +0800 From: =?utf-8?Q?Am=C3=A9rico?= Wang To: "Eric W. Biederman" Cc: =?utf-8?Q?Am=C3=A9rico?= Wang , Vivek Goyal , kosaki.motohiro@jp.fujitsu.com, linux kernel mailing list , Jarod Wilson Subject: Re: Query about kdump_msg hook into crash_kexec() Message-ID: <20110201073853.GB21239@cr0.nay.redhat.com> References: <20110131225939.GH11974@redhat.com> <20110201071933.GA21239@cr0.nay.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1481 Lines: 34 On Mon, Jan 31, 2011 at 11:33:15PM -0800, Eric W. Biederman wrote: >Américo Wang writes: > >> On Mon, Jan 31, 2011 at 05:59:39PM -0500, Vivek Goyal wrote: >>> >>>Anyway, if an image is loaded and we have setup to capture dump also >>>why do we need to save kmsg with the help of an helper. I am assuming >>>this is more of a debugging aid if we have no other way to capture the >>>kernel log buffer. So if somebody has setup kdump to capture the >>>vmcore, why to call another handler which tries to save part of the >>>vmcore (kmsg) separately. >>> >> >> Well, kmsg dumper is not only for panic/oops, it can also save kernel >> messages when the system is reboot/halt. >> >> Yeah, it is true that vmcore contains log_buf, but I think the users >> of ramoops/mtdoops are mainly those who don't have kdump configured >> in their kernels, they are cheaper than kdump, but less powerful > >The issue is the inane call inside crash_kexec. > >It requires both a kexec kernel to be loaded and it requires you to be >crashing. Given that when I audited the kmsg_dump handlers they really >weren't safe in a crash dump scenario we should just remove it. > Probably, I think we need to get rid of KMSG_DUMP_KEXEC. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/