From: Pavel Machek <pavel@ucw.cz>
To: David Brownell <david-b@pacbell.net>
Cc: rtc-linux@googlegroups.com,
kernel list <linux-kernel@vger.kernel.org>,
Alessandro Zummo <alessandro.zummo@towertech.it>
Subject: Re: RTC wakealarm write-only, still has 644 permissions
Date: Sun, 2 Dec 2007 12:36:09 +0100 [thread overview]
Message-ID: <20071202113609.GA1796@elf.ucw.cz> (raw)
In-Reply-To: <200711301310.40360.david-b@pacbell.net>
Hi!
> > > It's not an issue of accidental writes, it's an issue of there being
> > > no other synchronization for setting those alarms. Remember that both
> > > RTC_WKALM_SET and RTC_ALM_SET ioctls can set that same alarm, and so
> > > could a different userspace activity ...
> >
> > We have 3 interfaces to one hardware resource. I do not think kernel
> > should try to arbitrate it here. There's just one alarm clock with
> > three interfaces.
>
> Having three interfaces is bad enough ... ensuring that none of
> them can ever be used safely would be stupid.
They can be used safely. You just have to pick one and stay with
it. (And no, no-clobber hack does not help here. Or do you have
specific application where no-clobber hack helps?)
Anyway, with wildcarded dates, no-clobber is a problem -- because you
need to kill the alarm after you waken up, or it will repeat.
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
next prev parent reply other threads:[~2007-12-02 11:35 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-09-20 10:32 RTC wakealarm write-only, still has 644 permissions Pavel Machek
2007-09-20 10:50 ` Pavel Machek
2007-09-22 5:38 ` David Brownell
2007-10-02 9:36 ` Pavel Machek
2007-10-03 2:15 ` David Brownell
2007-11-28 23:26 ` Pavel Machek
2007-11-29 8:02 ` Tino Keitel
2007-11-29 18:10 ` David Brownell
2007-11-29 18:14 ` Alessandro Zummo
2007-11-30 20:35 ` Pavel Machek
2007-11-30 21:10 ` David Brownell
2007-11-30 21:20 ` Mark Lord
2007-11-30 21:27 ` Pavel Machek
2007-12-02 11:36 ` Pavel Machek [this message]
2007-12-02 16:03 ` David Brownell
[not found] ` <20071128230451.GA1547@elf.ucw.cz>
2007-11-28 23:26 ` Pavel Machek
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