linux-kernel - Re: [2.6.25] compat VDSO option not disabling

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Message-ID: <alpine.DEB.1.10.0804281322200.17060@mtl.rackplans.net>
Date:	Mon, 28 Apr 2008 13:24:52 -0400 (EDT)
From:	Gerhard Mack <gmack@...erfire.net>
To:	Jeremy Fitzhardinge <jeremy@...p.org>
cc:	Jiri Kosina <jkosina@...e.cz>, linux-kernel@...r.kernel.org
Subject: Re: [2.6.25] compat VDSO option not disabling

On Mon, 28 Apr 2008, Jeremy Fitzhardinge wrote:
> Gerhard Mack wrote:
> > On Sat, 26 Apr 2008, Jeremy Fitzhardinge wrote:
> >   
> > > Gerhard Mack wrote:
> > >     
> > > > I havn't enabled compat VDSO at the kernel command line or otherwise.
> > > > Something broke with this option.         
> > > Yes, you might be on to something.  I think I've been seeing that message
> > > when
> > > I wouldn't expect to.  I'll double-check.  Could you send your complete
> > > dmesg
> > > output?
> > > 
> > >     
> > Of course
> > 
> > 
> > Compat vDSO mapped to ffffe000.
> >   
> 
> I think this is just a false alarm.  sysenter_setup always prints this, but if
> compat mode isn't enabled this is just the address the compat vdso would be at
> if it were mapped.  You can confirm this by doing "cat /proc/self/maps" and
> making sure that there's nothing mapped at ffffe000.  And then cross confirm
> with "sysctl -w vm.vdso_enabled=2; cat /proc/self/maps" to make sure it
> appears.
> 

fd:~# cat /proc/self/maps | grep ffffe000
fd:~# sysctl -w vm.vdso_enabled=2
vm.vdso_enabled = 2
fd:~# cat /proc/self/maps | grep ffffe000
ffffe000-fffff000 r-xp 00000000 00:00 0          [vdso]

Your right.. can the boot message be made a bit more descriptive ?  I'm 
going to guess that I'm not the only one who makes this mistake.

	Gerhard


--
Gerhard Mack

gmack@...erfire.net

<>< As a computer I find your faith in technology amusing.
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