From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f196.google.com ([209.85.192.196]:39398 "EHLO mail-pf0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965341AbeF0OQQ (ORCPT ); Wed, 27 Jun 2018 10:16:16 -0400 Date: Wed, 27 Jun 2018 23:16:12 +0900 From: Sergey Senozhatsky To: Petr Mladek Cc: Sergey Senozhatsky , Steven Rostedt , Peter Zijlstra , Tetsuo Handa , Sergey Senozhatsky , linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH v2 0/3] printk: Deadlock in NMI regression Message-ID: <20180627141612.GA477@tigerII.localdomain> References: <20180627140817.27764-1-pmladek@suse.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180627140817.27764-1-pmladek@suse.com> Sender: stable-owner@vger.kernel.org List-ID: On (06/27/18 16:08), Petr Mladek wrote: > The commit 719f6a7040f1bdaf96 ("printk: Use the main logbuf in NMI > when logbuf_lock is available") brought back the possible deadlocks > in printk() and NMI. > > This is rework of the proposed fix, see > https://lkml.kernel.org/r/20180606111557.xzs6l3lkvg7lq3ts@pathway.suse.cz > > I realized that we could rather easily move the check to vprintk_func() > and still avoid any race. I believe that this is a win-win solution. > > > Changes against v1: > > + Move the check from vprintk_emit() to vprintk_func() > + More straightforward commit message > + Fix build with CONFIG_PRINTK_NMI disabled Did I miss out V1? > Petr Mladek (3): > printk: Split the code for storing a message into the log buffer > printk: Create helper function to queue deferred console handling > printk/nmi: Prevent deadlock when accessing the main log buffer in NMI Patch 3/3 is not in my mailbox, somehow [I checked the spam folder]. I'm not Cc-ed or the message got lost somewhere before it reached my gmail? -ss