Messages in this thread | | | From | "Zeh, Werner" <> | Subject | RE: [PATCH 1/1] x86/kernel/rtc: add sanity check for RTC date and time | Date | Thu, 9 Dec 2021 09:07:46 +0000 |
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> 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.
Werner
> -----Original Message----- > From: Alexandre Belloni <alexandre.belloni@bootlin.com> > Sent: Thursday, December 9, 2021 9:50 AM > To: Zeh, Werner (DI MC MTS SP HW 1) <werner.zeh@siemens.com> > 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 <alexandre.belloni@bootlin.com> > > > Sent: Friday, July 2, 2021 4:11 PM > > > To: Zeh, Werner (DI MC MTS SP HW 1) <werner.zeh@siemens.com> > > > 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 <werner.zeh@siemens.com> > > > > > > --- > > > > > > [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 <linux/export.h> > > > > > > #include <linux/pnp.h> > > > > > > #include <linux/of.h> > > > > > > +#include <linux/rtc.h> > > > > > > > > > > > > #include <asm/vsyscall.h> > > > > > > #include <asm/x86_init.h> > > > > > > @@ -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
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