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From: Pavel Machek <pavel@suse.cz>
To: Riley Williams <rhw@memalpha.cx>
Cc: Linux Kernel <linux-kernel@vger.kernel.org>
Subject: Re: PROBLEM: Linux updates RTC secretly when clock synchronizes
Date: Fri, 9 Nov 2001 10:32:54 +0100	[thread overview]
Message-ID: <20011109103254.B2620@atrey.karlin.mff.cuni.cz> (raw)
In-Reply-To: <20011108132639.A14160@atrey.karlin.mff.cuni.cz> <Pine.LNX.4.21.0111082252500.14996-100000@Consulate.UFP.CX>
In-Reply-To: <Pine.LNX.4.21.0111082252500.14996-100000@Consulate.UFP.CX>

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.

  reply	other threads:[~2001-11-09  9:33 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2001-10-31  0:33 PROBLEM: Linux updates RTC secretly when clock synchronizes Ian Maclaine-cross
2001-10-31  1:05 ` Kurt Roeckx
2001-10-31  2:55   ` Ian Maclaine-cross
2001-10-31 11:52     ` Kurt Roeckx
2001-11-01  0:52       ` Riley Williams
2001-11-01  1:26         ` Kurt Roeckx
2001-11-01 13:57         ` Alex Bligh - linux-kernel
2001-11-02  9:50           ` Riley Williams
2001-11-03 11:41             ` Alex Bligh - linux-kernel
2001-11-03 18:35               ` Riley Williams
2001-11-03 19:19                 ` Alex Bligh - linux-kernel
2001-11-03 21:04                 ` Kurt Roeckx
2001-11-06 10:01                 ` Pavel Machek
2001-11-06  9:57             ` Pavel Machek
2001-11-02 12:16 ` Pavel Machek
2001-11-05 23:08   ` Riley Williams
2001-11-06 10:17     ` Pavel Machek
2001-11-07  0:00       ` Riley Williams
2001-11-07  0:44         ` Alex Bligh - linux-kernel
2001-11-07  1:01           ` Kurt Roeckx
2001-11-07  1:15             ` Alex Bligh - linux-kernel
2001-11-07  9:24             ` Russell King
2001-11-08 12:26         ` Pavel Machek
2001-11-08 23:00           ` Riley Williams
2001-11-09  9:32             ` Pavel Machek [this message]
2001-11-09 21:11               ` Riley Williams
2001-11-09 21:30                 ` Pavel Machek
2001-11-09 22:54                   ` Riley Williams
2001-11-09 23:10                     ` Mark Zealey
2001-11-10 20:04                     ` Pavel Machek
2001-11-10 20:35                       ` Riley Williams
2001-11-10 20:43                         ` Pavel Machek
2001-11-10 20:49                         ` Doug McNaught
2001-11-06  0:20   ` Ian Maclaine-cross
2001-11-06 10:18     ` Pavel Machek
2001-11-08  5:09       ` Ian Maclaine-cross

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