[lxc-devel] [PATCH] allow all iX86 strings for lxc.arch

Dwight Engen dwight.engen at oracle.com
Mon Apr 28 20:29:52 UTC 2014


On Mon, 28 Apr 2014 16:05:24 -0400
Stéphane Graber <stgraber at ubuntu.com> wrote:

> On Mon, Apr 28, 2014 at 08:00:53PM +0000, Serge Hallyn wrote:
> > Quoting Dwight Engen (dwight.engen at oracle.com):
> > > On Mon, 28 Apr 2014 17:54:46 +0000
> > > Serge Hallyn <serge.hallyn at ubuntu.com> wrote:
> > > 
> > > > Quoting Dwight Engen (dwight.engen at oracle.com):
> > > > > This change accepts the same strings for lxc.arch that
> > > > > setarch(8) does.
> > > > > 
> > > > > When outputting the setting, use i386 instead of x86 since the
> > > > > later is not a valid input to setarch, nor will the kernel
> > > > > output UTS_MACHINE as x86. The kernel sets utsname.machine to
> > > > > i[3456]86, which are all map to PER_LINUX32.
> > > > > 
> > > > > Note that we continue to parse plain x86 as PER_LINUX32 so as
> > > > > not to break existing lxc configuration files.
> > > > > 
> > > > > Signed-off-by: Dwight Engen <dwight.engen at oracle.com>
> > > > 
> > > > Hi,
> > > > 
> > > > the first part (expanding the list of allowed inputs) seems
> > > > fine, but the second part seems like it could break existing
> > > > callers.
> > > 
> > > That's a good point. Using an older lxc version with a config
> > > that's been cloned with a newer one won't work because the older
> > > one won't parse i386. Maybe we should output i686 instead since
> > > older lxc's will parse that.
> > > 
> > > Or are you thinking it is too dangerous that there are callers
> > > outside of lxc that would be confused by seeing i686 instead of
> > > x86? I can drop
> > 
> > Right, whiel it's highly unlikely, I could see some script parsing
> > that output and being confused by new values.
> > 
> > > the output part, it just seemed a bit wrong that we're using a
> > > value that isn't valid from the kernel nor for setarch.
> > 
> > Admittedly even templates seem to use i686 rather than x86.  So
> > perhaps outputting i686 is the best thing to do.
> > 
> > -serge
> 
> I think it's reasonable to switch to i686 by default, I won't
> cherry-pick this change into stable so even if something does use
> this, it won't suddenly break for our stable 1.0.x users.

Stéphane, do you think just expanding the list part makes sense for
stable? If so I can split up the change and resend patches.


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