From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0ACC1C10F03 for ; Thu, 25 Apr 2019 09:37:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CD4E5214C6 for ; Thu, 25 Apr 2019 09:37:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="cXkUOQ2T" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728260AbfDYJhU (ORCPT ); Thu, 25 Apr 2019 05:37:20 -0400 Received: from mail-pf1-f195.google.com ([209.85.210.195]:34582 "EHLO mail-pf1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726304AbfDYJhU (ORCPT ); Thu, 25 Apr 2019 05:37:20 -0400 Received: by mail-pf1-f195.google.com with SMTP id b3so10878871pfd.1 for ; Thu, 25 Apr 2019 02:37:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=buZzVWfXn2UAyIgat8bZPbs15h+TmI1CAcI3bSwwJtg=; b=cXkUOQ2T9Nk4b/IevDkFKIhH0zDUw1cPgd5c3oj4NvNrE2YDkdjXu4Z14/KQBS+MwJ jM/kx0m/4PwsD46t7PHGtXeqSOwvBzcxN1hgvKL5X9IXGXY6i9ds0n+aOrXL8iUnDkW7 rKipi2b/IAuYhO//aR2f0yNlVTA3QcCTaNtiTdelmqhbdPiHtFI0dHv/KutuIGij0DFO 3HiLP/14x/3BNLa7sDqF4bNtyTDZ/whZ2FODS+sgLli+eQi5AB0OeRpi0oy9aBpUKmiE 6Q7fXrxFvveQy2oCD8+f+ng0le9XFNlGVTuJ4VclG3yUe9eRdKVyAPp5ljvQGDJkWtp7 WoLA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=buZzVWfXn2UAyIgat8bZPbs15h+TmI1CAcI3bSwwJtg=; b=g3pMVyJyUUSCOeiyLcRmE6Orn4a7YoYvaLfQTwvPJWTLaQR9KZaLFADWj3OUnGeacK 4VY2SC3Qypl+x9wiiPVOYxSOM2ZTb/PwmwSWtx7Ik9ykXdYdhpEg9u62vL+jtxseomz6 m1qc9I0HTlq8M8h3Ly+2CkubTQx44X8flH4619CvK4DH3/VPIIQILOXW3js3AtSI6yLr YjYLeONQ9CMnnAix5KTWlEYlGpoHYz5uYLQOOt+WsNaqGuHgnu/Zjl18+EvZiQfOUrOj 1vTBNXvJ9uQjYGrw32ZvurSN0keZc8zsNwm64oi8Yv3NP3t5e4uWsjCVPwSXp+uy5SF+ 8KyQ== X-Gm-Message-State: APjAAAVaXxEF/L23w6aDrPl3BVq/3F/ygkQ0bgYc4ixXGPzDUufUWF3h PmOiFK0HK4nr8XUsRsheLOs= X-Google-Smtp-Source: APXvYqwXR6O9Z7Qa48bVq+/xAIV/UGUhCK5hM9h2b3kJ6cJQS9fPFqQ6w9mxmt+vkjlGMfQPhTCs9w== X-Received: by 2002:a63:da51:: with SMTP id l17mr12710599pgj.115.1556185039260; Thu, 25 Apr 2019 02:37:19 -0700 (PDT) Received: from localhost ([175.223.37.83]) by smtp.gmail.com with ESMTPSA id d11sm23461859pgq.6.2019.04.25.02.37.16 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Thu, 25 Apr 2019 02:37:18 -0700 (PDT) Date: Thu, 25 Apr 2019 18:37:12 +0900 From: Sergey Senozhatsky To: Sergey Senozhatsky Cc: Petr Mladek , Steven Rostedt , Andrew Morton , linux-kernel@vger.kernel.org, Sergey Senozhatsky Subject: Re: [RFC][PATCH 1/2] printk: lock console_sem before we unregister boot consoles Message-ID: <20190425093712.GA11375@jagdpanzerIV> References: <20190423062511.1118-1-sergey.senozhatsky@gmail.com> <20190423062511.1118-2-sergey.senozhatsky@gmail.com> <20190424144924.lw5sgl7qa2yrpxsj@pathway.suse.cz> <20190425035233.GA8532@jagdpanzerIV> <20190425075002.r4g325fyh5jmabzs@pathway.suse.cz> <20190425075606.GA16917@jagdpanzerIV> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190425075606.GA16917@jagdpanzerIV> User-Agent: Mutt/1.11.4 (2019-03-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On (04/25/19 16:56), Sergey Senozhatsky wrote: > > Great idea! > > > > It would deserve a separate patch that moves the pr_info() > > and removes the invalid comment. > > > > Actually, the pr_info() would deserve a comment explaining > > why it should be called before console_unlock(). > > Good. So I think I'll drop patch #1 from the series, add > two more patches - invalid comment + pr_info() - and rework > locking in patch #3 (this should take care of a race which > patch #1 was intended to fix). D'oh, I can't drop patch #1, we still need to factor out __unregister_console(). Calling unregister_console(bcon) under console_sem will deadlock us. So I'll just end up having __registed_console() and __unregister_console(), both should be called under console_sem: register_console() { console_lock() __register_console() { ... for_each_console(bcon) if (bcon->flags & CON_BOOT) __unregister_console(bcon); } console_unlock() } -ss