Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932143AbcCCMRG (ORCPT ); Thu, 3 Mar 2016 07:17:06 -0500 Received: from bh-25.webhostbox.net ([208.91.199.152]:41381 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755934AbcCCMRD (ORCPT ); Thu, 3 Mar 2016 07:17:03 -0500 Subject: Re: [v3 PATCH 3/3] hpwdt: Use nmi_panic() when kernel panics in NMI handler To: Hidehiro Kawai , Andrew Morton , Thomas Mingarelli , Wim Van Sebroeck , Corey Minyard References: <20160303105741.4587.49047.stgit@softrs> <20160303105748.4587.70794.stgit@softrs> Cc: linux-watchdog@vger.kernel.org, linux-kernel@vger.kernel.org, Michal Hocko , Borislav Petkov , openipmi-developer@lists.sourceforge.net From: Guenter Roeck Message-ID: <56D82B3C.20209@roeck-us.net> Date: Thu, 3 Mar 2016 04:17:00 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.5.1 MIME-Version: 1.0 In-Reply-To: <20160303105748.4587.70794.stgit@softrs> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-Authenticated_sender: linux@roeck-us.net X-OutGoing-Spam-Status: No, score=-1.0 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - bh-25.webhostbox.net X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - roeck-us.net X-Get-Message-Sender-Via: bh-25.webhostbox.net: authenticated_id: linux@roeck-us.net X-Authenticated-Sender: bh-25.webhostbox.net: linux@roeck-us.net X-Source: X-Source-Args: X-Source-Dir: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2503 Lines: 74 On 03/03/2016 02:57 AM, Hidehiro Kawai wrote: > commit 1717f2096b54 ("panic, x86: Fix re-entrance problem due to > panic on NMI") introduced nmi_panic() which prevents concurrent and > recursive execution of panic(). It also saves registers for the > crash dump on x86 by later commit 58c5661f2144 ("panic, x86: Allow > CPUs to save registers even if looping in NMI context"). > > hpwdt driver can call panic() from NMI handler, so replace it with > nmi_panic(). Also, do some cleanups. > > Changes since V1: > - Use direct return instead of goto > - Combine the panic message string into a single line > > Signed-off-by: Hidehiro Kawai > Cc: Thomas Mingarelli > Cc: Wim Van Sebroeck > Cc: Guenter Roeck Acked-by: Guenter Roeck > Cc: linux-watchdog@vger.kernel.org In case you resend the series, please drop this Cc: from the commit logs. Please see usage of Cc: in Documentation/SubmittingPatches. Thanks, Guenter > --- > drivers/watchdog/hpwdt.c | 11 +++++------ > 1 file changed, 5 insertions(+), 6 deletions(-) > > diff --git a/drivers/watchdog/hpwdt.c b/drivers/watchdog/hpwdt.c > index 92443c3..a6c8797 100644 > --- a/drivers/watchdog/hpwdt.c > +++ b/drivers/watchdog/hpwdt.c > @@ -483,7 +483,7 @@ static int hpwdt_pretimeout(unsigned int ulReason, struct pt_regs *regs) > static int die_nmi_called; > > if (!hpwdt_nmi_decoding) > - goto out; > + return NMI_DONE; > > spin_lock_irqsave(&rom_lock, rom_pl); > if (!die_nmi_called && !is_icru && !is_uefi) > @@ -496,11 +496,11 @@ static int hpwdt_pretimeout(unsigned int ulReason, struct pt_regs *regs) > > if (!is_icru && !is_uefi) { > if (cmn_regs.u1.ral == 0) { > - panic("An NMI occurred, " > - "but unable to determine source.\n"); > + nmi_panic(regs, "An NMI occurred, but unable to determine source.\n"); > + return NMI_HANDLED; > } > } > - panic("An NMI occurred. Depending on your system the reason " > + nmi_panic(regs, "An NMI occurred. Depending on your system the reason " > "for the NMI is logged in any one of the following " > "resources:\n" > "1. Integrated Management Log (IML)\n" > @@ -508,8 +508,7 @@ static int hpwdt_pretimeout(unsigned int ulReason, struct pt_regs *regs) > "3. OA Forward Progress Log\n" > "4. iLO Event Log"); > > -out: > - return NMI_DONE; > + return NMI_HANDLED; > } > #endif /* CONFIG_HPWDT_NMI_DECODING */ > > > >