Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0AD40C433EF for ; Fri, 17 Dec 2021 21:53:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230254AbhLQVxX (ORCPT ); Fri, 17 Dec 2021 16:53:23 -0500 Received: from relay7-d.mail.gandi.net ([217.70.183.200]:58241 "EHLO relay7-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230242AbhLQVxV (ORCPT ); Fri, 17 Dec 2021 16:53:21 -0500 Received: (Authenticated sender: alexandre.belloni@bootlin.com) by relay7-d.mail.gandi.net (Postfix) with ESMTPSA id BBA1720004; Fri, 17 Dec 2021 21:53:17 +0000 (UTC) Date: Fri, 17 Dec 2021 22:53:17 +0100 From: Alexandre Belloni To: "Zeh, Werner" Cc: "x86@kernel.org" , "tglx@linutronix.de" , "mingo@redhat.com" , "bp@alien8.de" , "a.zummo@towertech.it" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH 1/1] x86/kernel/rtc: add sanity check for RTC date and time Message-ID: References: <20210614110946.15587-1-werner.zeh@siemens.com> <20210624081507.15602-1-werner.zeh@siemens.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/12/2021 09:07:46+0000, Zeh, Werner wrote: > > I'm not the maintainer for that part of the kernel, I expect this to go through > > the x86 tree. > > OK, understood. Thank you. > Any hint whom I can contact directly in this regard? > I had a hard time to debug this issue and it would be a pity if it will not make it in possibly causing issues for other users. > Well, tglx and mingo are in copy of the thread. You can probably resend with my: Acked-by: Alexandre Belloni to get their attention. > Werner > > > -----Original Message----- > > From: Alexandre Belloni > > Sent: Thursday, December 9, 2021 9:50 AM > > To: Zeh, Werner (DI MC MTS SP HW 1) > > Cc: tglx@linutronix.de; mingo@redhat.com; bp@alien8.de; x86@kernel.org; > > a.zummo@towertech.it; linux-kernel@vger.kernel.org > > Subject: Re: [PATCH 1/1] x86/kernel/rtc: add sanity check for RTC date and > > time > > > > Hello, > > > > On 09/12/2021 08:05:10+0000, Zeh, Werner wrote: > > > Hi Alexandre. > > > > > > Is there anything more I can do for that patch in order to get some process > > on it? > > > Or why is this patch stuck for a long time? > > > > > > > I'm not the maintainer for that part of the kernel, I expect this to go through > > the x86 tree. > > > > > Thanks > > > Werner > > > > > > > -----Original Message----- > > > > From: Alexandre Belloni > > > > Sent: Friday, July 2, 2021 4:11 PM > > > > To: Zeh, Werner (DI MC MTS SP HW 1) > > > > Cc: tglx@linutronix.de; mingo@redhat.com; bp@alien8.de; > > > > x86@kernel.org; a.zummo@towertech.it; linux-kernel@vger.kernel.org > > > > Subject: Re: [PATCH 1/1] x86/kernel/rtc: add sanity check for RTC > > > > date and time > > > > > > > > On 30/06/2021 06:25:44+0000, Zeh, Werner wrote: > > > > > Hi Alexandre > > > > > > > > > > > Hello, > > > > > > > > > > > > On 24/06/2021 10:15:07+0200, Werner Zeh wrote: > > > > > > > The timekeeper is synchronized with the CMOS RTC when it is > > > > initialized. > > > > > > > If the RTC buffering is bad (not buffered at all, empty > > > > > > > battery) the RTC registers can contain random data. In order > > > > > > > to avoid date and time being completely rubbish check the > > > > > > > sanity of the registers before calling mktime64. If the values > > > > > > > are not valid, set tv_sec to 0 so that at least the starting time is valid. > > > > > > > > > > > > > > Signed-off-by: Werner Zeh > > > > > > > --- > > > > > > > [resent due to wrong lkml address] [added RTC maintainers to > > > > > > > the recipients] This change introduces the same validity check > > > > > > > that is already done in drivers/rtc/interface.c. > > > > > > > If it is not done here, the timekeeper can be set up wrongly > > > > > > > in the first run and won't be corrected once the RTC driver is > > > > > > > started because the validity check in the RTC driver drops the > > > > > > > time and date due to invalid entries. > > > > > > > > > > > > > > arch/x86/kernel/rtc.c | 12 +++++++++++- > > > > > > > 1 file changed, 11 insertions(+), 1 deletion(-) > > > > > > > > > > > > > > diff --git a/arch/x86/kernel/rtc.c b/arch/x86/kernel/rtc.c > > > > > > > index > > > > > > > 586f718b8e95..f4af7b18c6c0 100644 > > > > > > > --- a/arch/x86/kernel/rtc.c > > > > > > > +++ b/arch/x86/kernel/rtc.c > > > > > > > @@ -9,6 +9,7 @@ > > > > > > > #include > > > > > > > #include > > > > > > > #include > > > > > > > +#include > > > > > > > > > > > > > > #include > > > > > > > #include > > > > > > > @@ -64,6 +65,7 @@ void mach_get_cmos_time(struct timespec64 > > > > *now) > > > > > > { > > > > > > > unsigned int status, year, mon, day, hour, min, sec, century = 0; > > > > > > > unsigned long flags; > > > > > > > + struct rtc_time tm = {0}; > > > > > > > > > > > > > > /* > > > > > > > * If pm_trace abused the RTC as storage, set the > > > > > > > timespec to 0, @@ > > > > > > > -118,7 +120,15 @@ void mach_get_cmos_time(struct timespec64 > > > > *now) > > > > > > > } else > > > > > > > year += CMOS_YEARS_OFFS; > > > > > > > > > > > > > > - now->tv_sec = mktime64(year, mon, day, hour, min, sec); > > > > > > > + tm.tm_sec = sec; > > > > > > > + tm.tm_min = min; > > > > > > > + tm.tm_hour = hour; > > > > > > > + tm.tm_mday = day; > > > > > > > + tm.tm_mon = mon; > > > > > > > + tm.tm_year = year; > > > > > > > + now->tv_sec = 0; > > > > > > > + if (rtc_valid_tm(&tm) == 0) > > > > > > > > > > > > Doesn't that make the x86 architecture depend on CONFIG_RTC_LIB? > > > > > > > > > > > CONFIG_RTC_LIB is already default enabled for x86, see > > arch/x86/Kconfig. > > > > > Do you have any other dependencies in mind I have overseen? > > > > > > > > > > > > > Nope, everything is fine, it would be better if we could get rid of > > > > mach_get_cmos_time but I don't have any clue as to why this is > > necessary. > > > > > > > > > > > > -- > > > > Alexandre Belloni, co-owner and COO, Bootlin Embedded Linux and > > > > Kernel engineering > > > > > > https://bootlin.com > > > > > > > -- > > Alexandre Belloni, co-owner and COO, Bootlin Embedded Linux and Kernel > > engineering > > https://bootlin.com -- Alexandre Belloni, co-owner and COO, Bootlin Embedded Linux and Kernel engineering https://bootlin.com