From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757334AbcEDJah (ORCPT ); Wed, 4 May 2016 05:30:37 -0400 Received: from mail.skyhub.de ([78.46.96.112]:43623 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757206AbcEDJae (ORCPT ); Wed, 4 May 2016 05:30:34 -0400 Date: Wed, 4 May 2016 11:30:31 +0200 From: Borislav Petkov To: Matt Fleming Cc: linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org, Ard Biesheuvel , Kweh Hock Leong , "Bryan O'Donoghue" , joeyli Subject: Re: [PATCH] efi/capsule: Make efi_capsule_pending() lockless Message-ID: <20160504093031.GA4074@pd.tnic> References: <1462054407-9735-1-git-send-email-matt@codeblueprint.co.uk> <20160503090229.GC27540@pd.tnic> <20160503141201.GW2839@codeblueprint.co.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20160503141201.GW2839@codeblueprint.co.uk> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 03, 2016 at 03:12:01PM +0100, Matt Fleming wrote: > We can find ourselves in the reboot code even if the admin has not > executed the reboot command. The trace above shows we entered because > the kernel panic()'d and it was booted with panic=-1. I knew you were gonna say something like that... > Right. You could find yourself in this situation if you're in the > middle of a capsule update and the box panics and reboots. Like you > said, there's really not much you can do there to ensure the update > completes. Your best option is to just not block and hang the machine. Hmmm, so panic() does bust_spinlocks() and efi_capsule_pending() could look at oops_in_progress which is set by bust_spinlocks() and that would probably solve the panic case but maybe the normal reboot case would still hang... > Note that in the panic() -> emergency_restart() case the reboot > notifiers are not called at all. And then there's that. -- Regards/Gruss, Boris. ECO tip #101: Trim your mails when you reply.