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=-11.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 E3D15C433E2 for ; Tue, 8 Sep 2020 00:08:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AA8FB2193E for ; Tue, 8 Sep 2020 00:08:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="YHGL1MCJ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728188AbgIHAH6 (ORCPT ); Mon, 7 Sep 2020 20:07:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49450 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727058AbgIHAH4 (ORCPT ); Mon, 7 Sep 2020 20:07:56 -0400 Received: from mail-oi1-x241.google.com (mail-oi1-x241.google.com [IPv6:2607:f8b0:4864:20::241]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D5BA6C061573 for ; Mon, 7 Sep 2020 17:07:56 -0700 (PDT) Received: by mail-oi1-x241.google.com with SMTP id 11so6543839oiq.6 for ; Mon, 07 Sep 2020 17:07:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:reply-to:references :mime-version:content-disposition:in-reply-to:user-agent; bh=0MQIFD0wSalUsY9jIwWCsu5F2vysByo4q9dNLulJ/BE=; b=YHGL1MCJ0qBeAdroqQwPzNeRgphRAZwvlt1bZQSqOdTCKQIOo1NCczfWD7rrkfEC76 wUlyVWhTmY+o6YX9wr2V9H9ZmmXDdZXr8ofNtZKLBhbXSIuCHNUixPdDBu+qCP6lkLl4 HlAW/r/upZQVvGXyI3DutyYz91ognzMFDJ68ukDPqZk81ZYdJfBKUIJj5GYeFKraFpRX sk+J0dmHR9eeWGLbdXchWHVIWSlvr7aCj8sQjD8wGCAt8wgxGnj8uQ1oTD6oIhCkB6QQ 7LbuPmbfFp6t3OTXaPyl7Cl2gEYDOdJdmsZo9fFW3MoGIB056fUgEUfYdQPmTwv6p1MJ y6lA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :reply-to:references:mime-version:content-disposition:in-reply-to :user-agent; bh=0MQIFD0wSalUsY9jIwWCsu5F2vysByo4q9dNLulJ/BE=; b=kevnSfw1XQHY3k0Vj0kFfkHdhRUvVJZBgWauhNGQan9/QyliYJ+4uoiYJvk59sDx0J K0X6FyifcKMLOlaz+TErBG+YvoRdFSYADmCijqZDkRVJUF8GV1rmlVC6rZhAA9/47nPc mA3zYTyfc7fzx0cY14HZexdbymDeJCpmyQ6Cv8/xkiDPM8OLllDOA4B4wn71tg49SYEF E7sH7HUneVVTILCIvJC6EnZVsUj8Tply28dpSSJbMlBdfy7MPdjlNL8IUCA6NakfAiSD K6LUWQaXmrC9xsBkRsHLEDYT64oqQg7DFBdAUoVkgTErsIalkHYGbr+aJIETBC1e6IsJ kYGg== X-Gm-Message-State: AOAM531z1LoQdmEviQNbS/pYeil48WGSr6rl7pXkjqDttWP/s+Ubl2AW Do5t0Ln5SoWqnzk2RxITSA== X-Google-Smtp-Source: ABdhPJylqM+6LzCyyHHbYv5f+3+wRyhKMMat4iC74kHjMarIVyRYEWMM2QveN4Qjm7uF5280ucheSQ== X-Received: by 2002:aca:fc07:: with SMTP id a7mr1085851oii.106.1599523676274; Mon, 07 Sep 2020 17:07:56 -0700 (PDT) Received: from serve.minyard.net ([47.184.170.156]) by smtp.gmail.com with ESMTPSA id h24sm2764562otj.33.2020.09.07.17.07.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 07 Sep 2020 17:07:55 -0700 (PDT) Received: from minyard.net (unknown [IPv6:2001:470:b8f6:1b:84ed:77c1:d49f:5e6b]) by serve.minyard.net (Postfix) with ESMTPSA id C503B18003B; Tue, 8 Sep 2020 00:07:54 +0000 (UTC) Date: Mon, 7 Sep 2020 19:07:53 -0500 From: Corey Minyard To: Markus Boehme Cc: openipmi-developer@lists.sourceforge.net, Arnd Bergmann , Greg Kroah-Hartman , linux-kernel@vger.kernel.org, Stefan Nuernberger , SeongJae Park , Amit Shah Subject: Re: [PATCH 2/3] ipmi: Add timeout waiting for device GUID Message-ID: <20200908000753.GC15602@minyard.net> Reply-To: minyard@acm.org References: <1599495937-10654-1-git-send-email-markubo@amazon.com> <1599495937-10654-2-git-send-email-markubo@amazon.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1599495937-10654-2-git-send-email-markubo@amazon.com> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Sep 07, 2020 at 06:25:36PM +0200, Markus Boehme wrote: > We have observed hosts with misbehaving BMCs that receive a Get Device > GUID command but don't respond. This leads to an indefinite wait in the > ipmi_msghandler's __get_guid function, showing up as hung task messages > for modprobe. > > According to IPMI 2.0 specification chapter 20, the implementation of > the Get Device GUID command is optional. Therefore, add a timeout to > waiting for its response and treat the lack of one the same as missing a > device GUID. This patch looks good. It's a little bit of a rewrite, but the reasons are obvious. -corey > > Signed-off-by: Stefan Nuernberger > Signed-off-by: Markus Boehme > --- > drivers/char/ipmi/ipmi_msghandler.c | 16 ++++++++++++---- > 1 file changed, 12 insertions(+), 4 deletions(-) > > diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c > index 2b213c9..2a2e8b2 100644 > --- a/drivers/char/ipmi/ipmi_msghandler.c > +++ b/drivers/char/ipmi/ipmi_msghandler.c > @@ -3184,18 +3184,26 @@ static void guid_handler(struct ipmi_smi *intf, struct ipmi_recv_msg *msg) > > static void __get_guid(struct ipmi_smi *intf) > { > - int rv; > + long rv; > struct bmc_device *bmc = intf->bmc; > > bmc->dyn_guid_set = 2; > intf->null_user_handler = guid_handler; > rv = send_guid_cmd(intf, 0); > - if (rv) > + if (rv) { > /* Send failed, no GUID available. */ > bmc->dyn_guid_set = 0; > - else > - wait_event(intf->waitq, bmc->dyn_guid_set != 2); > + goto out; > + } > > + rv = wait_event_timeout(intf->waitq, bmc->dyn_guid_set != 2, 5 * HZ); > + if (rv == 0) { > + dev_warn_once(intf->si_dev, > + "Timed out waiting for GUID. Assuming GUID is not available.\n"); > + bmc->dyn_guid_set = 0; > + } > + > +out: > /* dyn_guid_set makes the guid data available. */ > smp_rmb(); > > -- > 2.7.4 >