Re: RTC wakealarm write-only, still has 644 permissions

From: Pavel Machek
Date: Tue Oct 02 2007 - 05:36:57 EST


Hi!

> > > ...should they be changed to 200? Or perhaps file should be readable?
>
> No, mode 644 is fine. No reason to prevent "other" people from
> reading the alarm time (is there?) and if you write a legal value,
> that will work. So $SUBJECT is no problem at all.

Yep, agreed. I was confused by fact that it does not give invalid
values back.

> > > root@amd:/sys/class/rtc/rtc0# cat wakealarm
> > > root@amd:/sys/class/rtc/rtc0# echo 132719 > wakealarm
>
> At which point I'd expect
>
> # echo $?
>
> would indicate the write failed. That's a LONG time in the
> past (January 2, 1970), so that setting would be rejected.

echo $? says 0 here :-(.

> > > root@amd:/sys/class/rtc/rtc0#
> > >
> > > ...standard PC with reasonably recent kernel...
>
> Yeah, well a "standard PC" is chock full of fairly bizarrely
> glitchey hardware. Clocks and timers have more than their
> fair share, or x86_64 NOHZ support would be merged by now!

:-). Ok. Thinkpad x60.
Pavel


--
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(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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