Re: PROBLEM: Linux updates RTC secretly when clock synchronizes

Pavel Machek (pavel@suse.cz)
Fri, 9 Nov 2001 10:32:54 +0100


Hi!

> >>>> least as KERN_DEBUG if not as KERN_NOTICE) whenever the RTC is
> >>>> written to. It's too important a subsystem to be left hidden like
> >>>> it currently is.
>
> >>> This can be as well done in userland, enforced by whoever does rtc
> >>> writes, no?
>
> >> If some idiot writes a hwclock replacement that doesn't do logging...
>
> > Then it is *his* problem. That's no excuse for putting it into kernel.
>
> So you believe viruses are a good thing to have? Sorry, I have to
> disagree with you.

> Take the position of a sysadmin who can't understand why the system
> clock on his computer keeps getting randomly changed under Linux, and
> has verified using another operating system that it isn't a hardware
> problem, then ask yourself what said sysadmin would expect from the
> kernel to help him/her track the problem down. Would said sysadmin
> prefer to be told...
>
> 1. "Look in the system log - you'll get a message every time any
> program writes to the RTC."
>
> 2. "Sorry, you'll have to go through every piece of software on
> your system and find the one that's updating the system clock
> that shouldn't be."
>
> According to your comments, you prefer (2). I most definitely prefer
> (1).

Hmm, and if some malicious software insmods kernel module to work
around your printk()?

We are talking root only here. If sofware with uid 0 is malicious, you
have big problems.
Pavel

-- 
Casualities in World Trade Center: 6453 dead inside the building,
cryptography in U.S.A. and free speech in Czech Republic.
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